CN112013473A - Air conditioner control method - Google Patents

Abstract

The invention discloses a control method of an air conditioner. The control method of the air conditioner includes: in a cooling mode, obtaining the cooling superheat degree of the refrigerant outflow end of a reheat heat exchanger; comparing the cooling superheat degree and the cooling target superheat degree; If the superheat degree is greater than the cooling target superheat degree, reduce the opening degree of the reheat regulating valve; if the cooling superheat degree is less than the cooling target superheat degree, increase the opening degree of the reheat regulating valve; if the cooling superheat degree is equal to the cooling target superheat degree The target superheat degree, maintain the opening degree of the reheat regulating valve. The technical scheme of the present invention is beneficial to improve the refrigeration efficiency of the indoor heat exchanger in the refrigeration mode.

Description

Air conditioner control method

technical field

The invention relates to the technical field of air conditioners, in particular to a control method of an air conditioner.

Background technique

Due to the complexity of the weather, the air conditioner needs to have multiple functions at the same time to meet people's needs. For example, in order to overcome the weather with very high humidity, people need the air conditioner with dehumidification function. However, in the existing air conditioner with dehumidification function, in the process of cooling, the subcooling degree of the heat exchanger on the indoor side is unreasonably adjusted, so that the cooling effect of the heat exchanger on the indoor side in the cooling mode is not good.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a control method of an air conditioner, which aims to make the air conditioner with constant temperature dehumidification have better refrigeration performance in the refrigeration mode.

In order to achieve the above object, the present invention proposes a control method for an air conditioner, a control method for an air conditioner, characterized in that it includes an outdoor unit and an indoor unit, the outdoor unit includes a compression mechanism and an outdoor heat exchanger, and the indoor unit Including dehumidification heat exchanger and dehumidification throttling adjustment device;

The air conditioner further includes: a discharge pipe connected to the discharge side of the compression mechanism, a low-pressure suction pipe connected to the low-pressure suction side of the compression mechanism, and sequentially connected to the discharge pipe, the outdoor heat exchanger, and the The dehumidification throttling adjustment device, the liquid side piping of the dehumidification heat exchanger, and the gas side piping connecting the dehumidification heat exchanger and the low-pressure suction pipe, thereby forming a dehumidification circuit;

The indoor unit further includes a reheat heat exchanger, a reheat throttling adjustment device, and a thermal circulation device for sending the heat or cold of the indoor unit into the room;

The air conditioner further includes a high-low pressure pipe and a branch pipe branched from the discharge pipe, and the high and low pressure pipe connects the first intersection of the liquid-side pipe, the reheat throttling device, and all the other components. The reheat heat exchanger and the branch pipe are sequentially connected to form a reheat circuit, wherein the first intersection is located between the dehumidification and throttling adjustment device and the outdoor heat exchanger; the air conditioner The switch further includes a second switch capable of switching between a third switching state and a fourth switching state of the second switch, in which the second switch enables the high and low pressure piping communicates with the branch pipe, and in the fourth switching state, the second switch communicates the high and low pressure piping with the suction pipe;

The control method of the air conditioner includes:

In the outdoor unit constant temperature dehumidification and indoor unit cooling mode, obtain the cooling superheat degree of the refrigerant inflow end of the liquid side piping;

Compare the cooling superheat with the cooling target superheat;

If the cooling superheat degree is less than the cooling target superheat degree, reduce the opening degree of the reheat regulating valve;

If the refrigeration superheat degree is greater than the refrigeration target superheat degree, increase the opening degree of the reheat regulating valve;

If the cooling superheat degree is equal to the cooling target superheat degree, the opening degree of the reheat regulating valve is maintained.

Optionally, the air conditioner further includes a gas-liquid separator and an economizer, the gas-liquid separator is arranged on the low-pressure suction pipe; the economizer is arranged in the liquid between the outdoor heat exchanger and the first intersection. On the side piping, the return pipe of the economizer communicates with the gas-liquid separator; wherein, the economizer is provided with a first refrigerant flow path and a second refrigerant flow path, and the two ends of the first refrigerant flow path are respectively It is communicated with the liquid side piping at both ends of the economizer; one end of the second refrigerant flow path is communicated with the liquid side piping through the liquid intake pipe, and the other end is communicated with the medium pressure suction port of the compressor through the return pipe; There is a liquid taking control valve;

If the cooling superheat degree is greater than the cooling target superheat degree, the specific steps of increasing the opening degree of the reheat throttling adjustment device include:

If the cooling superheat degree is greater than the cooling target superheat degree;

Obtain the current opening of the reheat throttling device, and compare the current opening with the target opening range;

If the current opening degree is smaller than the maximum value of the target opening degree range, the opening degree of the reheat throttle adjustment device is increased.

Optionally, after the step of acquiring the current opening degree of the reheat throttling adjustment device and comparing the current opening degree with the target opening degree range, the method further includes:

If the current opening is greater than or equal to the maximum value of the target opening range, adjust the opening of the liquid intake throttle valve to reduce the cooling superheat.

Optionally, if the cooling superheat degree is less than the cooling target superheat degree, the specific steps of reducing the opening degree of the reheating throttle adjustment device include:

If the cooling superheat degree is less than the cooling target superheat degree;

Obtain the current opening of the reheat throttling device, and compare the current opening with the target opening range;

If the current opening degree is smaller than the maximum value of the target opening degree range, the opening degree of the reheat throttling adjustment device is reduced.

Optionally, after the step of acquiring the current opening degree of the reheat throttling adjustment device and comparing the current opening degree with the target opening degree range, the method further includes:

If the current opening is greater than or equal to the maximum value of the target opening range, adjust the opening of the liquid intake throttle valve to increase the cooling superheat.

Optionally, the return pipe is communicated with the gas-liquid separator through a low-pressure suction pipe, and a second control valve is provided on the return pipe or a connecting pipe between the return pipe and the low-pressure suction pipe.

Optionally, the air conditioner further includes an economizer; the economizer is arranged on the liquid side piping between the outdoor heat exchanger and the first intersection, and the return pipe of the economizer is connected to the medium pressure suction of the compressor. The economizer is provided with a first refrigerant flow path and a second refrigerant flow path, and both ends of the first refrigerant flow path are respectively connected with the liquid side piping at both ends of the economizer; one end of the second refrigerant flow path The liquid taking pipe is communicated with the liquid side piping, and the other end is communicated with the medium-pressure suction port of the compressor through the return pipe; a liquid taking regulating valve is arranged on the liquid taking pipe.

Optionally, the inflow end of the liquid taking pipe is communicated with the liquid side piping between the economizer and the outdoor side heat exchanger; or,

The inflow end of the liquid taking pipe communicates with the liquid side piping between the economizer and the first intersection.

Optionally, the outdoor unit further includes a first switch capable of switching between a first switch state of the first switch and a second switch state of the first switch,

In the first switching state, the first switching device communicates the liquid-side piping with the suction pipe and communicates the gas-side piping with the discharge pipe,

In the second switching state, the first switch communicates the first pipe and the discharge pipe and communicates the gas-side pipe and the suction pipe.

Optionally, the control method of the air conditioner further includes:

Obtain the dehumidification cooling superheat degree of the refrigerant outlet of the dehumidification heat exchanger;

Compare dehumidification cooling superheat and dehumidification cooling target superheat;

If the dehumidification refrigeration superheat degree is less than the dehumidification refrigeration target superheat degree, reduce the opening degree of the dehumidification throttling adjustment device;

If the dehumidification refrigeration superheat degree is greater than the dehumidification refrigeration target superheat degree, increase the opening degree of the dehumidification throttling adjustment device;

If the dehumidification refrigeration superheat degree is equal to the dehumidification refrigeration target superheat degree, keep the opening degree of the dehumidification throttling adjustment device.

Optionally, the opening degree of the dehumidification adjustment device and the opening degree of the reheat adjustment device are adjusted alternately.

Optionally, before the step of acquiring the refrigeration superheat degree of the refrigerant outflow end of the reheat heat exchanger, the method further includes the steps:

Detect the opening adjustment of the dehumidification throttling adjustment device;

If the opening degree adjustment of the dehumidification and throttling adjustment device is being performed, the cooling superheat degree of the refrigerant outflow end of the reheat heat exchanger will not be obtained;

If the opening degree of the dehumidification and throttling adjustment device is not adjusted, obtain the cooling superheat degree of the refrigerant outflow end of the reheat heat exchanger.

The technical solution of the present invention is to first obtain the cooling superheat degree of the refrigerant flow outlet of the reheat heat exchanger in the cooling mode; then compare the cooling superheat degree with the cooling target superheat degree, and then, if the cooling superheat degree is less than the cooling target superheat degree , increase the opening degree of the reheating throttling adjustment device; if the cooling superheat degree is greater than the cooling target superheat degree, reduce the opening degree of the reheating throttling adjustment device; if the cooling superheat degree is equal to the cooling target superheat degree, keep the reheating adjustment The opening degree of the flow regulating device makes the reheating throttle valve have a suitable opening degree to ensure the subcooling degree of the reheating heat exchanger, thereby ensuring the cooling effect of the reheating heat exchanger.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

1 is a schematic structural diagram of an embodiment of an air conditioner of the present invention in a heating mode;

Fig. 2 is the internal structure schematic diagram of the economizer at A place in Fig. 1;

3 is a schematic structural diagram of an embodiment of the air conditioner of the present invention in a cooling mode;

4 is a schematic structural diagram of an embodiment of the air conditioner of the present invention in a constant temperature dehumidification mode;

5 is a schematic flowchart of an embodiment of a control method for an air conditioner according to the present invention;

6 is a schematic flowchart of another embodiment of a control method for an air conditioner according to the present invention;

7 is a schematic flowchart of another embodiment of a control method for an air conditioner according to the present invention;

FIG. 8 is a schematic flowchart of still another embodiment of a control method for an air conditioner according to the present invention;

9 is a schematic structural diagram of another embodiment of the air conditioner of the present invention in a cooling mode;

10 is a schematic structural diagram of another embodiment of the air conditioner of the present invention in a heating mode;

11 is a schematic structural diagram of another embodiment of the air conditioner of the present invention in a constant temperature dehumidification mode;

Figure 12 is a schematic diagram showing that the total cooling demand of the indoor unit of the air conditioner of the present invention is greater than the total heating demand;

Figure 13 is a schematic diagram of the total cooling demand of the indoor unit of the air conditioner of the present invention being equal to the total heating demand;

Fig. 14 is a schematic diagram showing that the total cooling demand of the indoor unit of the air conditioner of the present invention is less than the total heating demand;

FIG. 15 is a schematic structural diagram of still another embodiment of the constant temperature dehumidification mode of the air conditioner of the present invention.

Description of reference numbers:

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relationship between various components under a certain posture (as shown in the accompanying drawings). The relative positional relationship, the movement situation, etc., if the specific posture changes, the directional indication also changes accordingly.

The specific structure of the air conditioner will be mainly described below.

1 to 8 , the entire pipeline structure and component arrangement of the air conditioner are first introduced; in the embodiment of the present invention, the air conditioner includes an outdoor unit 100 and an indoor unit 200 , and the outdoor unit 100 includes an enthalpy increasing compressor 110 structure and outdoor heat exchanger 141, the indoor unit 200 includes a dehumidification heat exchanger 220 and a dehumidification throttling adjustment device 240;

The air conditioner also includes: a discharge pipe 111 connected to the discharge side of the compressor 110, a low-pressure suction pipe 113 connected to the low-pressure suction side of the compressor 110, and sequentially connected to the discharge pipe 111 and the other. The outdoor heat exchanger 141 , the dehumidification and throttling adjustment device 240 , the liquid side piping 140 of the dehumidification heat exchanger 220 , and the gas side piping 150 connecting the dehumidification heat exchanger 220 and the low pressure suction pipe 113 , thus forming a dehumidification circuit;

The indoor unit 200 further includes a reheat heat exchanger 210, a reheat throttling device 230 and a thermal circulation device for sending the heat or cold of the indoor unit 200 into the room;

The air conditioner further includes a high-low pressure pipe 160 and a branch pipe 112 branched from the discharge pipe 111 . The high-low pressure pipe 160 connects the first intersection 211 of the liquid side pipe 140 to the reheating pipe 112 . The throttling adjustment device 230, the reheat heat exchanger 210 and the branch pipe 112 are connected in sequence to form a reheat circuit, wherein the first intersection 211 is located between the dehumidification throttling adjustment device 240 and the branch pipe 112. between the outdoor heat exchangers 141.

Wherein, the thermal cycle device may be a wind wheel in some embodiments, and the rotation of the wind wheel transports the air after heat exchange with the initial heat exchanger and the reheat heat exchanger into the room. Of course, in other embodiments, the thermal cycle device may also be a water cycle device, and the dehumidification heat exchanger and the reheat heat exchanger send heat or cold energy into the room through circulating water flowing in the water cycle device.

On the basis of the above-mentioned pipeline, the dehumidification heat exchanger 220 of the air conditioner cools, and the reheat heat exchanger 210 heats, so that constant temperature dehumidification can be realized. Wherein, the dehumidification and throttle adjustment device 240 includes a dehumidification throttle valve, and the reheat throttle adjustment device 230 includes a reheat throttle valve.

In some embodiments, the outdoor unit 100 further includes a first switch 131 capable of switching between a first switching state of the first switch 131 and a second switching state of the first switch 131,

In the first switching state, the first switch 131 communicates the liquid-side piping 140 with the suction pipe and communicates the gas-side piping 150 with the discharge pipe 111, and in the second switching state In the switching state, the first switch 131 communicates the liquid-side piping 140 with the discharge pipe 111 and communicates the gas-side piping 150 with the suction pipe.

Through the setting of the first switch 131, in the first switching state, the air conditioner is in a heating state, that is, the dehumidifying heat exchanger 220 and the reheating heat exchanger 210 heat at the same time; in the second switching state, the air conditioner is in a constant temperature Dehumidified state. The first switch 131 may be a four-way valve.

In some other embodiments, the air conditioner further includes a second switch 132, the second switch 132 can switch between the third switching state and the fourth switching state of the second switch 132, in the first switching state In the third switching state, the second switch 132 communicates the high and low pressure piping 160 with the branch pipe 112 , and in the fourth switching state, the second switch 132 connects the high and low pressure pipes 160 . The piping 160 communicates with the suction pipe.

Through the setting of the second switch 132, in the third switching state, the air conditioner is in a constant temperature dehumidification state; in the fourth switching state, the air conditioner is in a cooling state, that is, the dehumidifying heat exchanger 220 and the reheating heat exchanger 210 are at the same time refrigeration. The second switch 132 may be a four-way valve. The reheat throttle adjustment device 230 includes a reheat throttle valve, and the dehumidification throttle adjustment device 240 includes a dehumidification throttle valve. Also connected to the second switch 132 is an auxiliary branch pipe 170. When the high and low pressure pipes 160 communicate with the branch pipe 112, the auxiliary branch pipe 170 communicates with the suction pipe; when the high and low pressure pipes 160 communicate with the low pressure suction pipe 113, the auxiliary branch pipe 170 communicates with the low-pressure suction pipe 113 and the branch pipe 112 . The auxiliary branch pipe 170 is provided with a filter 171 and a capillary 172 .

Of course, in some embodiments, the first switch 131 and the second switch 132 can exist at the same time, so that the air conditioner can be switched in three states: constant temperature dehumidification, single heating, and single cooling.

In order to better adjust the subcooling degree of the outdoor heat exchanger 141, the air conditioner further includes an outdoor side throttle adjustment device 142, and the outdoor side throttle adjustment device 142 is located between the economizer 143 and the outdoor side heat exchanger. On the liquid side piping 140 between the heaters 141 . The outdoor side throttle adjustment device 142 includes an outdoor throttle valve.

In some embodiments, in order to reduce the loss of refrigerant pressure on the liquid-side piping 140 , the air conditioner further includes a first check valve 134 , and the first check valve 134 is connected in parallel with the outdoor side throttle adjustment device 142 . set up. The conduction direction of the first one-way valve 134 can be set according to different working conditions. It can be set so that the outdoor heat exchanger 141 conducts unidirectionally to the first intersection 211, or it can be set so that the first intersection 211 changes to the outdoor. Heater 141 conducts unidirectionally, and the former is taken as an example. When throttling is not required, the one-way valve 134 is turned on as much as possible, and when throttling is required, the outdoor side throttling adjusting device 142 is opened. The outdoor side throttle adjustment device 142 may be an electromagnetic throttle valve. In some embodiments, when the outdoor side throttle adjustment device is a large-diameter throttle valve, the first one-way valve may not be provided; when the outdoor side throttle adjustment device is a small-diameter throttle valve, the first one-way valve may be installed as much as possible. The first one-way valve relieves the pressure in the throttling device, thereby protecting the throttling device.

In some embodiments, in order to improve the ability of the air conditioner to heat at low temperatures, the air conditioner further includes an economizer 143 ; the economizer 143 is disposed on the liquid side between the outdoor heat exchanger 141 and the first intersection 211 On the piping 140 , the return pipe 146 of the economizer 143 communicates with the medium-pressure suction port of the compressor 110 . The return pipe 146 may have various forms. The return pipe 146 may only include the return pipe body, or may include the return pipe body and the first communication pipe 148. One end of the first communication pipe 148 is communicated with the return pipe body, and the other end is in communication with the return pipe body. It communicates with the medium pressure suction port of the compressor 110 .

A first control valve 133 is provided on the return pipe 146 or on the first communication pipe 148 between the return pipe 146 and the medium-pressure suction port of the compressor 110 . The compressor 110 at this time is the jet enthalpy compressor 110, and has a low-pressure suction port and a medium-pressure suction port.

The economizer 143 itself has a throttling function. The economizer 143 is provided with a first refrigerant flow path 143a and a second refrigerant flow path 143b. 140 is communicated; one end of the second refrigerant flow path 143b is communicated with the liquid side piping 140 through the liquid taking pipe 145, and the other end is communicated with the medium pressure suction port of the compressor 110 through the return pipe 146; the liquid taking pipe 145 is provided with Liquid intake throttle valve 144. One end of the first refrigerant fluid is communicated with the refrigerant inlet of the economizer 143 , and the other end is communicated with the refrigerant outlet of the economizer 143 . One end of the liquid intake pipe 145 is communicated with the liquid side piping 140, the other end is communicated with the second refrigerant flow path 143b, one end of the return pipe 146 is communicated with the medium pressure suction port of the compressor 110, and the other end is communicated with the second refrigerant flow path 143b .

In this way, after being switched by the first switch 131 and the second switch 132, the exhaust gas from the compressor 110 enters the reheat heat exchanger 210 and the dehumidification heat exchanger 220 respectively for heating, and the reheat heat exchanger 210 and the dehumidification heat exchanger The liquid refrigerant from the heater 220 enters the economizer 143 and is divided into two parts: the first part is directly throttled and depressurized by the outdoor side throttling device 142 (electronic expansion valve), and then enters the outdoor heat exchanger 141 to evaporate and absorb heat; the second part After being throttled and depressurized by the liquid intake throttle valve 144 (electronic expansion valve), it enters the economizer 143 through the liquid intake pipe 145 to absorb heat and evaporate. The evaporated medium-pressure saturated steam passes through the return pipe 146, and the first control valve 133 is connected to the The pipe 148 enters the medium-pressure suction port of the compressor 110, and is mixed with the refrigerant at the low-pressure suction port of the compressor 110 and compressed together, which solves the problems of small refrigerant flow, low return air pressure, and high compression ratio in a low-temperature environment, and improves the Low temperature heating capacity and system reliability. Through the technology of the present invention, when the outdoor ambient temperature is low, the system design of the air jet enthalpy increasing compressor 110 and the economizer 143 increases the refrigerant suction volume of the compressor 110 in the low temperature environment, thereby increasing the low temperature heating capacity and reducing the low temperature at the same time. The compression ratio in the environment can improve the reliability of the system.

In order to improve the liquid taking effect, the inflow end of the liquid taking pipe 145 is communicated with the liquid side piping 140 between the economizer 143 and the outdoor heat exchanger 141. In other embodiments, the inflow end of the liquid taking pipe 145 may also be The liquid-side piping 140 between the economizer 143 and the first intersection 211 communicates with each other. That is, the refrigerant flows in from the refrigerant outflow end of the economizer 143, which is beneficial to improve the reliability of liquid extraction.

In some other embodiments, in order to avoid unpleasant abnormal sound when the refrigerant in the vapor-liquid two-phase state passes through the indoor throttling device, the air conditioner further includes a gas-liquid separator 120 and an economizer 143 . The economizer 120 is arranged on the low pressure suction pipe 113; the economizer 143 is arranged on the liquid side piping 140 between the outdoor heat exchanger 141 and the first intersection 211, and the return pipe 146 of the economizer 143 is connected to the gas The liquid separator 120 is in communication. The return pipe 146 can have various forms. The return pipe 146 may only include the return pipe body, or may include the return pipe body and the second communication pipe 147. One end of the second communication pipe 147 is communicated with the return pipe body, and the other end is in communication with the return pipe body. It communicates with the gas-liquid separator 120 .

In order to facilitate control, in some examples, the return pipe 146 communicates with the gas-liquid separator 120 through the low-pressure suction pipe 113 , and the return pipe 146 or the second connection pipe 147 between the return pipe 146 and the low-pressure suction pipe 113 is on the A second control valve 149 is provided.

The present invention further reduces the outdoor heat exchange by adopting the system design with economizer 143 on the basis of the three-pipe dehumidification and reheating scheme, and by controlling the liquid intake throttle valve 144 (electronic expansion valve) in the design circuit of the system with economizer 143 The condensing temperature of the refrigerant at the outlet of the device 141 increases the degree of subcooling, so that the refrigerant is completely condensed into a liquid state. The liquid refrigerant is throttled and depressurized by the indoor electronic expansion valve and then enters the indoor heat exchanger to absorb heat and evaporate. When it is liquid, it can solve the abnormal sound of refrigerant caused by gas-liquid two-phase state.

After the exhaust gas of the compressor 110 is switched by the first switch 131, the high-pressure and high-temperature gaseous refrigerant enters the outdoor heat exchanger 141 for condensation and heat exchange, and the gas-liquid two-phase medium-temperature and high-pressure refrigerant from the outdoor heat exchanger 141 enters the economizer 143. Then it is divided into two parts: the first part is throttled and depressurized through the liquid intake throttle valve 144, and then enters the economizer 143 through the liquid intake pipe 145 to absorb heat and evaporate, and the evaporated gaseous refrigerant passes through the return pipe 146, and the second control valve 149 (electromagnetic valve) and the connecting pipe 147 enter the gas-liquid separator 120 and enter the suction port of the compressor 110 after mixing with the gaseous refrigerant after the heat absorption and evaporation of the indoor heat exchanger. After the second part is further condensed and exchanged from the economizer 143, The gas-liquid two-phase refrigerant becomes a pure liquid refrigerant, and this part of the pure liquid refrigerant flows into the room, and then enters the dehumidification heat exchanger 220 and the reheat heat exchange after being throttled and depressurized by the dehumidification throttle valve and the reheat throttle valve. The device 210 performs endothermic evaporation. Since the state of the refrigerant entering the dehumidification control valve and the reheat control valve (electronic expansion valve) changes from a gas-liquid two-phase state to a pure liquid state, the problem of abnormal refrigerant noise caused by the gas-liquid two-phase refrigerant passing through the throttling device is solved. .

In this embodiment, through the technical solution of the present invention, the condensation temperature of the refrigerant at the outlet of the outdoor heat exchanger 141 can be further reduced, and the degree of subcooling can be increased, so that the refrigerant is completely condensed from a gas-liquid two-phase state to a liquid state, and the liquid refrigerant passes through the indoor electronic expansion. When the valve (dehumidification throttle valve and reheat throttle valve) is throttled and depressurized, it enters the indoor heat exchanger to absorb heat and evaporate, and the refrigerant passing through the indoor throttle device (dehumidification throttle valve and reheat throttle valve) is in full liquid state , which can solve the problem of abnormal sound of refrigerant caused by gas-liquid two-phase refrigerant passing through the throttling device, and improve user satisfaction

It is worth noting that, in some embodiments, the return pipe 146 is respectively connected to the medium-pressure suction port of the compressor 110 and the gas-liquid separator 120 through different communication pipes. At this time, the two communication pipes (the first communication pipe and the second communication pipe The first control valve 133 (near the compressor 110) and the second control valve 149 (near the gas-liquid separator 120) are respectively set on the pipe). The return pipe at this time includes a return pipe body and two communication pipes. In the heating mode, close the second control valve 149 and open the first control valve 133 to allow refrigerant to flow into the compressor 110 to improve the heating capacity; in the cooling mode or constant temperature dehumidification mode, close the first control valve 133 and open The second control valve 149 to eliminate abnormal sound. Of course, in some embodiments, due to special operating conditions, the second control valve 149 may also be closed and the first control valve 133 may be opened. This arrangement enables the air conditioner to adjust the first control valve 133 and the second control valve 149 according to specific conditions, thereby improving the heating capacity of the air conditioner in the heating mode and reducing noise in the cooling and constant temperature dehumidification modes.

Regarding the specific connection between the compressor 110 and the economizer 143, the compressor 110 is a jet enthalpy increasing compressor 110. In addition to the conventional high-pressure exhaust port P, the low-pressure intake port S, and the medium-pressure intake port M, the compressor 110 is also (ie, the steam injection port), the medium-pressure refrigerant vapor enters the compressor 110 through the steam injection port to increase the effective flow of the refrigerant.

The a port of the economizer 143 is connected to one end of the outdoor heat exchanger 141, the b port of the economizer 143 is connected to the second intersection 212, the c port of the economizer 143 is connected to the liquid taking pipe 145, and the d port of the economizer 143 is connected to The return pipe 146 is connected in series, the liquid taking throttle valve 144 is connected in series on the liquid taking pipe 145, the first control valve 133 is connected in series on the connecting pipe, the second control valve 149 is connected in series on another connecting pipe, and one end of the connecting pipe is connected to the connecting pipe. The medium-pressure suction port M of the compressor 110 is connected, and the other connecting pipe is connected to the inlet end of the gas-liquid separator 120 .

In some embodiments, the air conditioner further includes a plurality of indoor units 200, and the heat exchangers included in each indoor unit 200 may be different, for example, may include an indoor unit with a constant temperature and dehumidification function (with a dehumidification heat exchanger 220 and a reheater at the same time) heat exchanger 210), common cooling/heating internal unit (with only one heat exchanger 270 and corresponding throttling device 280), and an internal unit with a conversion device that can freely switch between cooling or heating states, among One or more, so that the air conditioner can perform mixed operation of constant temperature dehumidification, cooling, heating, etc. at the same time.

Specifically, the air conditioner further includes: a first connection pipe 260 branched from the second intersection 212 of the liquid side piping 140 , and a second connection pipe 250 branched from the gas side pipe 150 , the second intersection 212 is located between the dehumidification and throttling adjustment device 240 and the outdoor heat exchanger 141, the air conditioner further includes a plurality of indoor units 200, and the plurality of indoor units 200 are connected in parallel at on the first connecting pipe 260 and the second connecting pipe 250 .

In some embodiments, in order to improve the reliability of the second switch 132 , the second switch 132 does not use a four-way valve, but is controlled by two solenoid valves. Specifically, the high and low pressure piping 160 communicates with the branch pipe 112 and communicates with the low pressure suction pipe 113 or the gas side piping 150 , the branch pipe 112 is provided with a third control valve 310 , and the high and low pressure pipes 160 pass through the communication pipe 114 communicates with the low-pressure suction pipe 113 or with the gas-side piping, and the communication pipe 114 is provided with a fourth control valve 320 . It is worth noting that the end of the communication pipe 114 away from the high and low pressure piping 160 may be communicated with the gas side piping 150 between the first switch 131 and the indoor heat exchanger, or may be connected with the first switch 131 and the gas-liquid separator The gas-side piping 150 between them communicates with each other. Since the third control valve 310 and the fourth control valve 320 are separate control valves, compared with the four-way valve, the structure is simpler, and the stability and reliability are higher. In addition, the third control valve 310 and the fourth control valve 320 may be solenoid valves. The solenoid valve can still work stably and reliably when liquid refrigerant enters, but in the four-way valve, if liquid refrigerant enters, it will affect the stability of its operation. Therefore, the independent third control valve 310 and the fourth control valve are used. The control valve 320 can improve the stability and reliability of the operation and state switching of the air conditioner.

It is worth noting that the third control valve 310 and the fourth control valve 320 can be set to their states when they are powered off according to actual operating conditions. Taking the third control valve 310 as an example, during the operation of the air conditioner, the third control valve 310 maintains the normally open state for a long time. In the power-on state, most of its work can be completed. Only when the state of the third control valve 310 needs to be switched, it needs to be powered on. Similarly, if the third control valve 310 is kept normally closed for a long time, the Select it as a normally closed valve. In this way, the electric energy consumed by the second switch 132 (including the third control valve 310 ) during the operation of the air conditioner can be reduced, thereby facilitating the rational utilization of energy.

In some embodiments, in order to simplify the pipeline structure, the high and low pressure piping 160 , the branch pipe 112 and the low pressure suction pipe 113 are connected to the first connection Q. Of course, the low pressure suction pipe 113 can be connected to the other two through the communication pipe 114 tube connection. At this time, a three-way valve can be provided at the first connection Q to replace the two two-way valves. The three-way valve realizes that the high and low pressure piping 160 is communicated with the communication pipe 114 and the branch pipe 112 respectively, and can control the on-off of the communication pipe 114 and the branch pipe respectively. The convenience of the connection of the branch pipe 112.

Cooling Mode:

The high temperature and high pressure refrigerant is discharged from the exhaust pipe 111, passes through the first switch 131, the liquid side piping 140, the outdoor side heat exchanger and the economizer in sequence, and then enters the evaporative heat exchanger and the dehumidification heat exchanger respectively for cooling. One part flows out from the dehumidifier heat exchanger, passes through the gas-side piping 150 and the first switch 131 (in some embodiments, it may not be), and flows into the gas-liquid separator; the other part flows out from the evaporative heat exchanger and passes through the high and low pressure piping 160 Then it enters the communication pipe 114. When the communication pipe 114 is connected with the low-pressure suction pipe, the refrigerant enters the gas-liquid separator through the low-pressure suction pipe 113; when the communication pipe 114 is communicated with the gas side piping 150, the refrigerant flows into the The gas side piping 150 flows into the gas-liquid separator through the gas side piping 150 . During this process, the third control valve 310 is closed, and the fourth control valve 320 is opened.

Heating mode:

The high-temperature and high-pressure refrigerant is discharged from the exhaust pipe 111, and a part of the refrigerant passes through the first switch 131 (in some embodiments may not be) and the gas-side piping 150 in turn, and then enters the dehumidification heat exchanger for heating, and flows out from the dehumidification heat exchanger Then enter the liquid side piping 140; the other part enters the reheat heat exchanger for heating through the branch pipe 112 and the high and low pressure piping 160 in turn, flows out from the reheat heat exchanger and then enters the liquid side piping 140, passes through the economizer, The outdoor side heat exchanger and the first switch 131 then flow into the gas-liquid separator. During this process, the third control valve 310 is opened, and the fourth control valve 320 is closed.

Constant temperature dehumidification mode:

The high-temperature and high-pressure refrigerant is discharged from the exhaust pipe 111, and part of it passes through the first switch 131 (in some embodiments, there may be none), the liquid side piping 140, the outdoor side heat exchanger and the economizer, and then enters the dehumidification heat exchanger Refrigeration is carried out in the gas-liquid separator, and then flows into the gas-liquid separator through the gas-side piping 150 and the first switch 131 . The other part enters the reheat heat exchanger for heating through the branch pipe 112 and the high and low pressure piping 160 in sequence, and then flows into the dehumidification heat exchanger for cooling. During this process, the third control valve 310 is opened, and the fourth control valve 320 is closed.

In some embodiments, the air conditioner is also used to supply water for floor heating or to prepare domestic water for people.

When the air conditioner further includes a floor heating module, the air conditioner further includes a hot water exchange tank and a floor heating water flow pipe communicating with the hot water exchange tank; a floor heating heat exchanger is arranged in the hot water exchange tank, and the floor heating heat exchanger is The refrigerant inlet communicates with the high and low pressure piping, the refrigerant outlet communicates with the liquid side piping, and the gas side piping is provided with a sixth control valve.

Specifically, in this embodiment, the floor heating water pipe can be buried in the ground or in the wall, the floor heating water pipe is communicated with the hot water exchange tank, and the water in the hot water exchange tank can be circulated in the floor heating water pipe, so that the water temperature in the floor heating water pipe is the same as that in the hot water exchange tank. the water temperature is comparable. When the high temperature and high pressure refrigerant passes through, the floor heating heat exchanger exchanges heat with the water in the hot water exchange tank to heat the cold water in the water tank; when the low pressure refrigerant passes through, the floor heating heat exchanger exchanges heat with the water in the hot water exchange tank. , to cool the water in the hot water tank. When the floor heating heat exchanger is working, the sixth control valve can be selectively closed (close when the floor heating needs to be efficiently heated). At this time, the outdoor unit mainly serves the floor heating heat exchanger to improve the heat exchange efficiency of the floor heating heat exchanger. .

In some other embodiments, the air conditioner further includes: a first connecting pipe branched from a second intersection of the liquid-side piping, and a second connecting pipe branched from the gas-side piping, The second intersection is located between the dehumidification and throttling adjustment device and the outdoor heat exchanger; the air conditioner further includes a water treatment device, the water treatment device includes a water heat exchanger and a water container, the The water heat exchanger is used for heating or cooling the water in the water container, and the water heat exchanger is connected to the first connecting pipe and the second connecting pipe in parallel with the indoor unit. The water heat exchanger heats or cools the water in the water container. Of course, there can be multiple water containers, and multiple water heat exchangers can also be arranged in parallel. In this way, one water container can be used to hold hot water. Another water container holds cold water, so that cold and hot water can be supplied at the same time. When hot water is needed, a high-temperature refrigerant is passed through the water heat exchanger, so that heat energy can be transferred to the water in the container; when cooling water is needed, a low-temperature refrigerant is passed through the water heat exchanger, so that cold energy can be transferred. Give water in the container.

In different operation modes, in order to achieve better cooling, heating or constant temperature dehumidification effects, different adjustments need to be made to the dehumidification throttle valve, the reheat throttle valve, the liquid intake throttle valve 144 and the outdoor throttle valve. The following descriptions are made in the cooling mode, the heating mode and the constant temperature dehumidification mode.

Control method in cooling mode:

Adjustment of the subcooling degree of the economizer 143 (by adjusting the opening of the liquid intake throttle valve 144);

Air conditioner control methods include:

S10. In the cooling mode, obtain the liquid subcooling degree of the economizer 143; the subcooling degree is the temperature in the middle of the heat exchanger minus the temperature at the outlet of the heat exchanger;

Specifically, in this embodiment, the subcooling degree of the extracted liquid is the temperature in the middle of the economizer 143 minus the temperature of the refrigerant outlet of the economizer 143 . Obtain the temperature of the middle of the economizer 143 and the temperature of the refrigerant outlet respectively, and then subtract the temperature of the refrigerant outlet of the economizer 143 from the temperature of the middle of the economizer 143 . Among them, the subcooling degree of liquid extraction refers to the difference between the temperature of port a of the economizer and the temperature of port b, that is, the temperature value of Ta-Tb.

S20, compare the subcooling degree of the liquid taking and the target subcooling degree of taking the liquid;

The target subcooling degree of liquid taking is taken as an example of 5-8 degrees Celsius, and the calculated subcooling degree of liquid taking is compared with the target subcooling degree of liquid taking.

S31. If the subcooling degree of the liquid extraction is greater than the target subcooling degree of the liquid extraction, reduce the opening degree of the liquid extraction throttle valve 144; the opening degree of the liquid extraction throttle valve 144 is gradually adjusted, and each adjustment is calculated and compared. The subcooling degree of the liquid taken and the target subcooling degree of the liquid taken, until the subcooling degree of the liquid taken falls within the range of the target subcooling degree of the liquid taken.

When the subcooling degree of the liquid taking is greater than the target subcooling degree of taking the liquid, it means that the temperature difference between the middle part of the economizer 143 and the refrigerant outlet is large, and the temperature difference needs to be reduced. At this time, the opening of the liquid taking throttle valve 144 needs to be reduced, to adjust the heat exchange, thereby reducing the temperature difference between the middle of the economizer 143 and the refrigerant outlet. So that the subcooling degree of the liquid sample is within the range of the target subcooling degree of the liquid sample. At this time, it can be ensured that the refrigerant flowing from the economizer 143 to the dehumidification throttle valve and the reheat throttle valve is pure liquid, and abnormal noise can be completely eliminated.

S32, if the subcooling degree of the liquid taking is less than the target subcooling degree of the liquid taking, increase the opening degree of the liquid taking throttle valve 144;

When the subcooling degree of the liquid taking is less than the target subcooling degree of taking the liquid, it means that the temperature difference between the middle part of the economizer 143 and the refrigerant outlet is small, and the temperature difference needs to be increased. At this time, it is necessary to increase the opening of the liquid taking throttle valve 144. to adjust the heat exchange, thereby increasing the temperature difference between the middle of the economizer 143 and the refrigerant outlet. So that the subcooling degree of the liquid sample is within the range of the target subcooling degree of the liquid sample. At this time, it can be ensured that the refrigerant flowing from the economizer 143 to the dehumidification throttle valve and the reheat throttle valve is pure liquid, and abnormal noise can be completely eliminated.

S33. If the subcooling degree of the liquid taking is equal to the target subcooling degree of the liquid taking, keep the opening degree of the liquid taking throttle valve 144.

When the subcooling degree of the extraction liquid is within the target subcooling degree range of the extraction liquid, the temperature difference of the economizer 143 is appropriate, which can effectively ensure that the refrigerant flowing from the economizer 143 to the dehumidification throttle valve and the reheating throttle valve is pure liquid, which can completely eliminate the Different sound.

The cooling superheat adjustment of the reheat heat exchanger 210 and the dehumidification cooling superheat adjustment of the dehumidification heat exchanger 220

The control method of the air conditioner also includes:

S100, the outdoor unit is dehumidified at a constant temperature, and in the indoor unit cooling mode, the cooling superheat degree of the refrigerant inlet of the liquid side piping is obtained;

The cooling superheat degree is the difference between the temperature Tb in the middle of the reheat heat exchanger 210 and the temperature Tc at the outlet of the refrigerant. The temperature Tb in the middle of the reheat heat exchanger 210 and the temperature Tc of the refrigerant outlet of the reheat heat exchanger 210 during cooling are respectively detected, and the difference between the two is calculated.

S200, compare the cooling superheat and the cooling target superheat;

The target superheat degree of refrigeration is 0～10℃, taking 1～4℃ as an example. Compare the calculated cooling superheat with the cooling target superheat.

S310, if the cooling superheat degree is less than the cooling target superheat degree, reduce the opening degree of the reheating throttling adjustment device 230;

When the cooling superheat degree is less than the cooling target superheat degree, it means that the temperature difference between the middle of the reheat heat exchanger 210 and the refrigerant outlet is small, and the temperature difference needs to be increased. At this time, the opening of the reheat throttle valve needs to be reduced to adjust heat exchange, thereby increasing the temperature difference between the middle of the reheat heat exchanger 210 and the refrigerant outlet. so that the cooling superheat degree is within the range of the cooling target superheat degree. At this time, the heat exchange efficiency of the reheat heat exchanger 210 can be ensured, so as to ensure the heat exchange efficiency of the refrigerant in the reheat heat exchanger 210, so that the liquid refrigerant can be fully evaporated and the heat exchange effect can be improved. The opening degree of the reheat throttle valve is gradually adjusted, and the cooling superheat degree and the cooling target superheat degree are calculated and compared every time the adjustment is made until the cooling superheat degree falls within the range of the cooling target superheat degree.

In some examples, if the cooling superheat degree is less than the cooling target superheat degree, the step of reducing the opening degree of the reheat throttling adjustment device 230 specifically includes:

If the cooling superheat degree is less than the cooling target superheat degree;

obtaining the current opening degree of the reheat throttling adjusting device 230, and comparing the current opening degree with the target opening degree range;

In this embodiment, the opening range of the reheat throttle valve is limited, which can be limited by the structure of the reheat throttle valve itself, that is, the limit opening degree and the limit closing degree; The reheat throttle valve can only move within the preset target opening range.

If the current opening degree is greater than the minimum value of the target opening degree range, the opening degree of the reheat throttle adjusting device 230 is reduced; that is, when the current opening degree of the reheat throttle valve has further room for reduction, the reheat throttle valve can be directly reduced. Thermal throttle valve opening.

If the current opening degree is less than or equal to the minimum value of the target opening degree range, the opening degree of the liquid intake throttle valve 144 is adjusted to increase the refrigeration superheat degree. That is, when the current opening degree of the reheat throttle valve has no room for further reduction, the current opening degree of the reheat throttle valve is maintained (in some special conditions, the opening degree even needs to be increased to make the reheat throttle valve The opening degree of the valve returns to the target opening degree range), and the temperature and pressure of the refrigerant in the refrigerant pipe are adjusted by adjusting the opening degree of the liquid intake throttle valve 144, so as to finally achieve the adjustment of the cooling superheat degree of the reheat heat exchanger 210. The purpose is to ensure the heat exchange effect.

Among them, the opening adjustment of the reheat adjustment device can be adjusted according to the difference between the cooling superheat degree and the cooling target superheat degree. The greater the number of steps; the smaller the difference between the cooling superheat degree and the cooling target superheat degree, the less the number of steps to reduce the reheating throttling adjustment device each time.

In the same way, the greater the difference between the cooling superheat degree and the cooling target superheat degree, the more steps the reheat throttling adjustment device is increased each time; the smaller the difference between the cooling superheat degree and the cooling target Fewer steps for the large reheat throttling device.

S320, if the cooling superheat degree is greater than the cooling target superheat degree, increase the opening degree of the reheating throttling adjustment device 230;

When the cooling superheat degree is greater than the cooling target superheat degree, it means that the temperature difference between the middle of the reheat heat exchanger 210 and the refrigerant outlet is large, and the temperature difference needs to be reduced. At this time, the opening of the reheat throttle valve needs to be increased to adjust heat exchange, thereby reducing the temperature difference between the middle of the economizer 143 and the refrigerant outlet. so that the cooling superheat degree is within the range of the cooling target superheat degree. At this time, the heat exchange efficiency of the reheat heat exchanger 210 can be ensured, so as to ensure the heat exchange efficiency of the refrigerant in the reheat heat exchanger 210, so that the liquid refrigerant can be fully evaporated and the heat exchange effect can be improved.

In some embodiments, if the cooling superheat degree is less than the cooling target superheat degree;

obtaining the current opening degree of the reheat throttling adjusting device 230, and comparing the current opening degree with the target opening degree range;

If the current opening degree is smaller than the maximum value of the target opening degree range, the opening degree of the reheat throttle adjusting device 230 is increased. That is, when the current opening degree of the reheat throttle valve has further room for increase, the opening degree of the reheat throttle valve can be directly increased.

If the current opening degree is greater than or equal to the maximum value of the target opening degree range, the opening degree of the liquid intake throttle valve 144 is adjusted to reduce the refrigeration superheat degree.

That is, when the current opening degree of the reheat throttle valve does not have room for further increase, the current opening degree of the reheat throttle valve should be maintained (in some special conditions, the opening degree may even need to be reduced, so that the reheat throttle valve can The opening degree of the flow valve returns to the target opening degree range), and the temperature and pressure of the refrigerant in the refrigerant pipe are adjusted by adjusting the opening degree of the liquid intake throttle valve 144, so as to finally adjust the refrigeration superheat degree of the reheat heat exchanger 210. purpose to ensure the heat transfer effect.

In some embodiments, in order to achieve the effect of eliminating abnormal sound faster, if the subcooling degree of the liquid extraction is greater than the target subcooling degree of the liquid extraction, the step of reducing the opening degree of the liquid extraction throttle valve includes:

If the subcooling degree of the liquid taken is greater than the target subcooling degree of the liquid taken;

Obtain the fourth temperature difference between the subcooling degree of the liquid taking and the target subcooling degree of taking the liquid;

The number of steps for reducing the opening degree of the liquid intake throttle valve according to the fourth temperature difference.

That is, different fourth temperature difference values will have different adjustment ranges. The larger the fourth temperature difference value is, the more steps the single adjustment is made, and the smaller the fourth temperature difference value is, the fewer the single adjustment steps are.

Specifically, the specific steps for reducing the number of steps of the opening degree of the liquid taking throttle valve according to the fourth temperature difference include:

comparing the fourth temperature difference value with the fourth preset temperature difference value;

If the fourth temperature difference value is greater than the fourth preset temperature difference value, the speed at which the liquid intake throttle valve decreases is step E/adjustment duration;

If the fourth temperature difference value is smaller than the fourth preset temperature difference value, comparing the fourth temperature difference value with the fifth preset temperature difference value;

If the fourth temperature difference value is greater than the fifth preset temperature difference value, and is less than or equal to the fourth preset temperature difference value, the speed at which the liquid throttling valve is reduced is F step/adjustment duration; wherein, the value of E is greater than F;

If the fourth temperature difference value is less than or equal to the fifth preset temperature difference value, and is greater than zero, the opening of the liquid intake throttle valve is maintained.

It is worth noting that the values of E and F may be a specific number of steps or a range of steps, which will be described below with examples. Tp is the fourth temperature difference value=(Ta-Tb)-T target subcooling degree of liquid sampling.

Tp>3, reduce the opening degree of the electronic expansion valve 144 in the economizer loop by 4 steps/every 120 seconds, wherein the value of E is 4, of course, in some examples, it can also be 3-5, the fourth preset The temperature difference value is 3°C; it is worth noting that, in this embodiment, the adjustment period of the liquid taking throttle valve is 120 seconds.

2<Tp≤3, decrease the opening degree of the electronic expansion valve 144 in the economizer circuit by 2 steps/120 seconds. Wherein, the value of F is 2, of course, in some examples, it may also be 1-3, and the fifth preset temperature difference value is 2°C.

0<Tp≤2, the opening degree of the electronic expansion valve 144 in the economizer circuit is maintained. Since the subcooling degree of the liquid taking is greater than the target subcooling degree of the liquid taking, the fourth temperature difference is greater than zero.

Similarly, if the subcooling degree of the liquid taken is less than the target subcooling degree of the liquid taken, the fifth temperature difference at this time will be less than zero, and the calculation logic thereof is also very similar.

The specific steps of increasing the opening degree of the liquid taking throttle valve if the liquid taking subcooling degree is less than the liquid taking target subcooling degree include:

If the subcooling degree of the liquid taken is less than the target subcooling degree of the liquid taken;

Obtain the fifth temperature difference between the subcooling degree of the liquid taking and the target subcooling degree of taking the liquid;

The number of steps for increasing the opening degree of the liquid intake throttle valve according to the fifth temperature difference.

That is, different fifth temperature difference values will have different adjustment ranges. The smaller the fifth temperature difference value is, the more steps are in a single adjustment, and the larger the fifth temperature difference value is, the fewer the steps in a single adjustment.

Specifically, the specific steps of increasing the number of steps of the opening degree of the liquid taking throttle valve according to the fifth temperature difference include:

comparing the fifth temperature difference value with the sixth preset temperature difference value;

If the fifth temperature difference value is less than or equal to the sixth preset temperature difference value, the rate at which the liquid intake throttle valve increases is G step/adjustment duration;

If the fifth temperature difference value is greater than the sixth preset temperature difference value, the rate at which the liquid intake throttle valve increases is H steps/adjustment duration; wherein, the value of G is greater than H.

It is worth noting that the values of G and H may be a specific number of steps, or may be a range of steps, which will be described with an example below. Tq is the fifth temperature difference value=(Ta-Tb)-T target subcooling degree of liquid sampling.

Tq≤-2, increase the opening degree of the electronic expansion valve 144 in the economizer loop by 4 steps/every 120 seconds, wherein the value of G is 4, of course, in some examples, it can also be 3-5. The temperature difference is set to be -2°C; it is worth noting that, in this embodiment, the adjustment period of the liquid sampling throttle valve is 120 seconds.

-2<Tq≤0, increase the opening degree of the electronic expansion valve 144 in the economizer circuit by 2 steps/every 120 seconds. Wherein, the value of H is 2, of course, in some instances, it can also be 1-3.

S330 , if the cooling superheat degree is equal to the cooling target superheat degree, keep the opening degree of the reheating throttle adjustment device 230 .

When the cooling superheat degree is within the cooling target superheat degree range, the temperature difference of the reheat heat exchanger 210 is appropriate, which can effectively ensure the evaporation efficiency of the reheat heat exchanger 210 and ensure the heat exchange effect of the reheat heat exchanger 210 .

When the outdoor unit is in the cooling state and the indoor unit is also in the cooling state:

The control method of the air conditioner also includes:

Obtain the cooling superheat of the refrigerant outlet of the reheat heat exchanger;

Compare the cooling superheat with the cooling target superheat;

If the cooling superheat degree is less than the cooling target superheat degree, reduce the opening degree of the reheating throttling adjustment device;

If the cooling superheat degree is greater than the cooling target superheat degree, increase the opening degree of the reheating throttling adjustment device;

If the cooling superheat degree is equal to the cooling target superheat degree, keep the opening degree of the reheating throttling device.

Among them, the opening adjustment of the reheat adjustment device can be adjusted according to the difference between the cooling superheat degree and the cooling target superheat degree. The more the number of steps, or the faster the adjustment speed; the smaller the difference between the cooling superheat degree and the cooling target superheat degree, the less the number of steps to reduce the reheat throttling adjustment device each time, or the adjustment speed. slower.

In the same way, the greater the difference between the cooling superheat degree and the cooling target superheat degree, the more steps the small reheat throttling adjustment device is increased each time, or the faster the adjustment speed; the cooling superheat degree is greater than the cooling target superheat degree. The smaller the difference is, the fewer steps the reheat throttling adjustment device needs to increase each time, or the slower the adjustment speed. The degree of cooling superheat is represented by Tu. When Tu is greater than 2°C, the opening of the indoor electronic expansion valve will be larger. When Tu is less than 2°C, the opening of the indoor electronic expansion valve will be reduced. When Tu is equal to 2°C, the opening degree will be reduced. It remains unchanged; 2°C at this time is an example, and it can also be a range, such as 1.2-2.2°C.

Tu>6℃, the opening rate of the indoor electronic expansion valve is 10 steps/30 seconds;

4<Tu≤6℃, the opening rate of the indoor electronic expansion valve is 6 steps/60 seconds;

3＜Tu≤4℃, the opening rate of the indoor electronic expansion valve is 4 steps/60 seconds;

2＜Tu≤3℃, the opening rate of the indoor electronic expansion valve is 2 steps/120 seconds;

Tu=2℃, the opening of the indoor electronic expansion valve remains unchanged;

1≤Tu＜2℃, the rate of opening and closing of the indoor electronic expansion valve is 2 steps/120 seconds;

0≤Tu＜1℃, the opening and closing rate of the indoor electronic expansion valve is 4 steps/60 seconds;

Tu<0°C, the rate of opening and closing of the indoor electronic expansion valve is 8 steps/30 seconds.

In the cooling mode, regarding the degree of dehumidification and subcooling of the dehumidifying heat exchanger 220, since in the cooling mode, the dehumidifying heat exchanger 220 and the reheating heat exchanger 210 are cooled at the same time, the subcooling degree of the two is adjusted in the same way, as follows. brief introduction.

The control method of the air conditioner also includes:

Obtain the dehumidification and refrigeration superheat degree of the refrigerant flow outlet of the dehumidification heat exchanger 220;

The dehumidification cooling superheat is the refrigerant temperature in the middle of the dehumidification heat exchanger 220 minus the refrigerant temperature at the refrigerant outlet of the dehumidification heat exchanger 220 .

Compare dehumidification cooling superheat and dehumidification cooling target superheat;

If the dehumidification refrigeration superheat degree is less than the dehumidification refrigeration target superheat degree, reduce the opening degree of the dehumidification throttling adjustment device 240;

If the dehumidification refrigeration superheat degree is greater than the dehumidification refrigeration target superheat degree, increase the opening degree of the dehumidification throttling adjustment device 240;

If the dehumidification and cooling superheat degree is equal to the dehumidification and cooling target superheat degree, the opening degree of the dehumidification and throttling adjustment device 240 is maintained.

In the same way, if the adjustment opening of the dehumidification throttle valve reaches the limit value, the temperature and pressure of the refrigerant in the pipeline can be adjusted by adjusting the opening degree of the liquid intake valve, so as to achieve the purpose of adjusting the superheat degree of dehumidification and refrigeration, so as to ensure the dehumidification replacement. The heat exchange effect of the heater 220.

In the cooling mode, in order to make the liquid intake throttle valve 144 , the dehumidification throttle valve and the reheat throttle valve reach the adjustment target as soon as possible, the opening degrees of the three are not adjusted at the same time as possible. It is worth noting that, not only in the cooling mode, but also in the heating mode and the constant temperature dehumidification mode, if the adjustment between the liquid intake throttle valve 144, the dehumidification throttle valve and the reheat throttle valve will interfere with each other, Try to avoid adjusting all three at the same time.

Before the step of acquiring the cooling superheat degree of the refrigerant inflow end of the reheat heat exchanger 210, the following steps are further included:

Detecting the adjustment of the opening degree of the dehumidification throttling adjustment device 240;

If the opening degree adjustment of the dehumidification and throttling adjustment device 240 is being performed, the cooling superheat degree of the refrigerant outflow end of the reheat heat exchanger 210 is not obtained;

If the opening degree of the dehumidifying and throttling adjusting device 240 is not adjusted, the degree of cooling superheat at the refrigerant outflow end of the reheat heat exchanger 210 is obtained.

That is to say, before adjusting the opening of the reheat throttle valve, check whether the opening of the dehumidification throttle valve is being adjusted. If it is, avoid mutual interference between the two. Then adjust the opening of the reheat throttle valve. In order to avoid the simultaneous adjustment of the dehumidification throttle valve and the reheat throttle valve as much as possible, the cycle duration of the two can be set to the same, but the adjustment time settings of the two are different, and the opening degrees of the two are adjusted alternately. For example, the cycle duration is 20 seconds. In a certain period, the dehumidification throttle valve is adjusted after the first 20 seconds, the reheat throttle valve is adjusted after the second 20 seconds, and the reheat throttle valve is adjusted after the third 20 seconds. The dehumidification throttle valve is adjusted so that the two are not adjusted at the same time.

Similarly, before adjusting the opening of the reheat throttle valve, it is also necessary to detect the opening adjustment state of the liquid intake throttle valve 144 or the outdoor side throttle adjustment device. If it is being adjusted, wait until the adjustment is completed. make adjustments.

Before the step of obtaining the liquid sampling subcooling degree of the liquid sampling throttle valve 144, it also includes the steps:

Detecting the adjustment of the opening degree of the reheat throttling adjusting device 230;

If the reheat throttling adjusting device 230 is adjusting the opening degree, the subcooling degree of the liquid taking throttling valve 144 is not obtained;

If the opening degree adjustment of the reheat throttle adjusting device 230 is not performed, the liquid intake subcooling degree of the liquid intake throttle valve 144 is obtained.

That is, before adjusting the opening degree of the liquid intake throttle valve 144, first check whether the reheat throttle valve (dehumidification throttle valve) is adjusting the opening degree. If the opening degree is being adjusted, wait for the reheat throttle valve. After the adjustment of the opening degree of the valve (dehumidification throttle valve) is completed, the opening degree of the liquid intake throttle valve 144 is adjusted. If it is to adjust the opening degree, it can be adjusted directly.

In order to avoid the simultaneous opening adjustment of the liquid intake throttle valve 144 and the reheat throttle valve (dehumidification throttle valve), the adjustment period of the reheat throttle adjustment device 230 is smaller than that of the liquid intake throttle valve 144 cycle. For example, the adjustment period of the reheat throttle valve is 20 seconds, and the adjustment period of the liquid intake throttle valve 144 is 2 minutes, which can fully ensure the heat exchange effect of the reheat heat exchanger 210 (dehumidification heat exchanger 220) ( The cycle is short, the adjustment is fast, and the operation is accurate), and the generation of abnormal sounds can be minimized.

Control method in heating mode:

Superheat adjustment of liquid intake throttle valve 144;

The control method of the air conditioner includes:

S1. In the heating mode, obtain the superheat degree of the supplementary air of the economizer 143;

The exhaust superheat is equal to the exhaust temperature minus the exhaust pressure corresponding to the saturation temperature. The suction superheat is equal to the suction temperature minus the suction pressure corresponding to the saturation temperature. Among them, the superheat degree of the supplementary air refers to the difference between the temperature of the d port of the economizer and the temperature of the c port, that is, Td-Tc. This heating mode is the heating mode of the indoor unit, and the outdoor unit can be the heating mode.

S2. Compare the superheat degree of the supplemental gas with the target superheat degree of the supplementary gas;

The target superheat degree of the supplemental gas is 1 to 3°C, taking 2°C as an example.

S3-1. If the superheat degree of the supplemental gas is greater than the target superheat degree of the supplementary gas, increase the opening degree of the liquid intake throttle valve 144; the opening degree of the liquid intake throttle valve 144 is gradually adjusted, and each adjustment is calculated and compared. The supplemental gas superheat degree and the supplemental gas target superheat degree, until the supplemental gas superheat degree falls within the range of the supplementary gas target superheat degree.

When the superheat degree of the supplemental gas is greater than the target superheat degree of the supplementary gas, it means that the temperature difference between the suction or exhaust temperature and the saturation temperature is large, and the temperature difference needs to be reduced. The heat exchange is adjusted to reduce the temperature difference between the suction or exhaust temperature of the economizer 143 and the saturation temperature. So that the superheat degree of the supplemental gas is within the range of the target superheat degree of the supplementary gas. At this time, the refrigerant after being throttled and depressurized by the liquid intake throttling valve 144 (electronic expansion valve) passes through the liquid intake pipe 145 and then enters the economizer 143 to absorb heat and evaporate, and the evaporated medium-pressure saturated steam enters the compressor through the return pipe 146 The medium pressure suction port of 110 is mixed with the refrigerant of the low pressure suction port of compressor 110 and compressed together, which solves the problems of small refrigerant flow, low return air pressure and high compression ratio in low temperature environment, and improves the low temperature heating capacity and system. reliability.

In some embodiments, the opening range of the liquid intake throttle valve 144 is limited, which may be limited by the structure of the liquid intake throttle valve 144 itself, that is, the limit opening degree and the limit closing degree; it may also be due to special working conditions requirements, so that the liquid intake throttle valve 144 can only move within a preset target opening range.

If the superheat degree of the supplemental gas is greater than the target superheat degree of the supplementary gas, the specific steps of increasing the opening degree of the liquid intake throttle valve 144 include:

If the superheat degree of the supplemental gas is greater than the target superheat degree of the supplementary gas;

Obtain the current opening degree of the liquid intake throttle valve 144, and compare the current opening degree with the target opening degree range;

If the current opening degree is smaller than the maximum value of the target opening degree range, the opening degree of the liquid intake throttle valve 144 is increased.

That is, when the current opening degree of the liquid intake throttle valve 144 has further room for increase, the opening degree of the liquid intake throttle valve 144 can be directly increased.

If the current opening degree is greater than or equal to the maximum value of the target opening degree range, the opening degree of the outdoor side throttle adjustment device 142 is adjusted until the supplemental air superheat degree is less than or equal to the supplemental air target superheat degree. That is, if the current opening degree of the liquid intake throttle valve 144 does not have room for further increase, the current opening degree of the liquid intake throttle valve 144 should be maintained (in some special operating conditions, the opening degree may even need to be reduced, so that the extraction The opening degree of the liquid throttle valve 144 returns to the target opening degree range), and the temperature and pressure of the refrigerant in the refrigerant pipe are adjusted by adjusting the opening degree of the outdoor side throttling adjustment device 142, so as to finally achieve the adjustment of the economizer 143. The purpose of supplementing the air superheat is to ensure the effect of the enthalpy increasing compressor 110 on heating.

In some embodiments, in order to achieve the effect of increasing the enthalpy of gas injection faster, if the superheat degree of the supplemental gas is greater than the target superheat degree of the supplementary gas, the specific steps of increasing the opening of the liquid intake throttle valve include:

If the supplemental gas superheat degree is greater than the target supplemental gas superheat degree;

obtaining a first temperature difference between the supplemental gas superheat degree and the supplemental gas target superheat degree;

The number of steps for increasing the opening degree of the liquid intake throttle valve according to the first temperature difference.

That is, different first temperature difference values will have different adjustment ranges. The larger the first temperature difference value, the more steps of a single adjustment, and the smaller the first temperature difference value, the fewer steps of a single adjustment.

Specifically, the specific steps of increasing the number of steps of the opening degree of the liquid taking throttle valve according to the first temperature difference include:

comparing the first temperature difference value with the first preset temperature difference value;

If the first temperature difference value is greater than the first preset temperature difference value, the rate at which the liquid intake throttle valve increases is step A/adjustment duration;

If the first temperature difference value is smaller than the first preset temperature difference value, comparing the first temperature difference value with the second preset temperature difference value;

If the first temperature difference value is greater than the second preset temperature difference value, and is less than or equal to the first preset temperature difference value, the increase rate of the liquid intake throttle valve is B step/adjustment time; wherein, the value of A is greater than B ;

If the first temperature difference value is less than or equal to the second preset temperature difference value, and is greater than zero, the opening of the liquid intake throttle valve is maintained.

It is worth noting that the values of A and B may be a specific number of steps or a range of steps, which will be described with examples below. Tm is the first temperature difference value=(Td-Tc)-T target superheat degree of supplemental gas.

Tm>3, increase the opening degree of the electronic expansion valve 144 in the economizer loop by 4 steps/every 120 seconds, wherein the value of A is 4. Of course, in some examples, it can also be 3-5. The first preset The temperature difference value is 3°C; it is worth noting that, in this embodiment, the adjustment period of the liquid taking throttle valve is 120 seconds.

2<Tm≤3, increase the opening degree of the electronic expansion valve 144 in the economizer circuit by 2 steps/120 seconds. Wherein, the value of B is 2, of course, in some examples, it may also be 1-3, and the second preset temperature difference value is 2°C.

0<Tm≤2, the opening degree of the electronic expansion valve 144 in the economizer circuit is maintained. Since the supplemental gas superheat degree is greater than the supplemental gas target superheat degree, the first temperature difference is greater than zero.

Similarly, if the supplemental gas superheat degree is smaller than the supplemental gas target superheat degree, the second temperature difference at this time will be less than zero, and the calculation logic thereof is also very similar.

If the superheat degree of the supplemental gas is less than the target superheat degree of the supplementary gas, the specific steps of reducing the opening degree of the liquid intake throttle valve include:

If the superheat degree of the supplemental gas is less than the target superheat degree of the supplementary gas;

obtaining a second temperature difference between the supplemental gas superheat degree and the supplemental gas target superheat degree;

The number of steps for reducing the opening degree of the liquid intake throttle valve according to the second temperature difference.

That is to say, different second temperature difference values will have different adjustment ranges. The smaller the second temperature difference value is, the more steps the single adjustment is made, and the larger the second temperature difference value, the fewer the single adjustment steps.

Specifically, the specific steps of reducing the number of steps of the opening degree of the liquid taking throttle valve according to the second temperature difference include:

comparing the second temperature difference value with the third preset temperature difference value;

If the second temperature difference value is less than or equal to the third preset temperature difference value, the decreasing speed of the liquid taking throttle valve is C steps/adjustment duration;

If the second temperature difference value is greater than the third preset temperature difference value, the decreasing speed of the liquid intake throttle valve is D steps/adjustment duration; wherein, the value of C is greater than D.

It is worth noting that the values of C and D may be a specific number of steps or a range of steps, which will be described with examples below. Tn is the second temperature difference value=(Td-Tc)-T target superheat degree of supplemental gas.

Tn≤-2, reduce the opening degree of the electronic expansion valve 144 in the economizer loop by 4 steps/every 120 seconds, wherein the value of C is 4, of course, in some examples, it can also be 3-5, the third pre- The temperature difference is set to be -2°C; it is worth noting that, in this embodiment, the adjustment period of the liquid sampling throttle valve is 120 seconds.

-2<Tn≤0, decrease the opening degree of the electronic expansion valve 144 in the economizer circuit by 2 steps/120 seconds. Wherein, the value of D is 2, of course, in some instances, it can also be 1-3.

In the heating mode, before the step of obtaining the superheat degree of the supplementary air of the economizer, it also includes:

Get the outdoor ambient temperature T4;

Compare the outdoor ambient temperature T4 with the preset ambient temperature T4-ph;

If the outdoor ambient temperature is greater than or equal to the preset ambient temperature, close the liquid intake throttle valve;

If the outdoor ambient temperature is lower than the preset ambient temperature, obtain the superheat degree of the supplemental air of the economizer.

Specifically, in this embodiment, the preset ambient temperature T4-ph may be 0 to 7°C. Taking 5°C and 7°C as an example, when the current outdoor ambient temperature is higher than the preset ambient temperature, it means that the temporary ambient temperature is still higher than the preset ambient temperature. There is no need to increase the enthalpy of air injection to improve the heating performance, and the liquid intake throttle valve can be closed at this time. When the current outdoor ambient temperature is lower than the preset ambient temperature, it means that the compressor needs to increase the enthalpy so that it can improve the heating capacity in a low temperature environment. At this time, the liquid intake throttle valve should be opened and adjusted. .

S3-2. If the superheat degree of the supplemental gas is less than the target superheat degree of the supplementary gas, reduce the opening degree of the liquid intake throttle valve 144;

When the supplemental gas superheat degree is less than the supplemental gas target superheat degree, it means that the temperature difference between the suction or exhaust temperature and the saturation temperature is small, and the temperature difference needs to be increased. At this time, the opening of the liquid intake throttle valve 144 needs to be reduced, The heat exchange is adjusted to increase the temperature difference between the suction or discharge temperature of the economizer 143 and the saturation temperature. So that the superheat degree of the supplemental gas is within the range of the target superheat degree of the supplementary gas. At this time, the refrigerant after being throttled and depressurized by the liquid intake throttling valve 144 (electronic expansion valve) passes through the liquid intake pipe 145 and then enters the economizer 143 to absorb heat and evaporate, and the evaporated medium-pressure saturated steam enters the compressor through the return pipe 146 The medium pressure suction port of 110 is mixed with the refrigerant of the low pressure suction port of compressor 110 and compressed together, which solves the problems of small refrigerant flow, low return air pressure and high compression ratio in low temperature environment, and improves the low temperature heating capacity and system. reliability.

In some embodiments, if the supplemental gas superheat degree is less than the supplemental gas target superheat degree, the specific steps of reducing the opening degree of the liquid intake throttle valve 144 include:

If the superheat degree of the supplemental gas is less than the target superheat degree of the supplementary gas;

Obtain the current opening degree of the liquid intake throttle valve 144, and compare the current opening degree with the target opening degree range;

If the current opening degree is greater than the minimum value of the target opening degree range, the opening degree of the liquid intake throttle valve 144 is reduced.

That is, when the current opening degree of the liquid intake throttle valve 144 has a further reduction space, the opening degree of the liquid intake throttle valve 144 can be directly reduced.

If the current opening degree is less than or equal to the minimum value of the target opening degree range, reduce the opening degree of the outdoor side throttle device until the supplemental air superheat degree is greater than or equal to the supplementary air target superheat degree.

That is, if the current opening degree of the liquid intake throttle valve 144 does not have room for further reduction, the current opening degree of the liquid intake throttle valve 144 should be maintained (in some special conditions, the opening degree may even need to be increased to make the intake The opening degree of the liquid throttle valve 144 returns to the target opening degree range), and the temperature and pressure of the refrigerant in the refrigerant pipe are adjusted by adjusting the opening degree of the outdoor side throttling adjustment device 142, so as to finally achieve the adjustment of the economizer 143. The purpose of supplementing the air superheat is to ensure the effect of the enthalpy increasing compressor 110 on heating.

S3-3. If the superheat degree of the supplemental gas is equal to the target superheat degree of the supplementary gas, keep the opening degree of the liquid intake throttle valve 144. At this time, it means that the suction or discharge temperature is equal to the saturation temperature, and the economizer 143 can better obtain medium-pressure saturated steam. In this way, the enthalpy increasing effect of the enthalpy increasing compressor 110 can be effectively guaranteed, and the air conditioner can be operated more efficiently. Heating capacity in low temperature environment.

Heating and subcooling adjustment of reheat heat exchanger 210 (sequence)

In the heating mode, the following describes how to ensure the heating effect of the reheat heat exchanger 210 by adjusting the heating and subcooling degree of the reheat heat exchanger 210. The air conditioner includes a plurality of indoor units, and the control method of the air conditioner is also include:

Obtain the central temperature T2i of all the heating heat exchangers, and calculate the average T2avg of the central temperature of the heating heat exchangers;

Specifically, in this embodiment, the middle temperature T2i of each heating heat exchanger may be T21, T22, T23... T2n. The value of T2avg is the value of (T21+T22+T23+...+T2n)/n.

Calculate the third temperature difference between T2i and T2avg in the middle of the reheat heat exchanger in the heating mode;

Taking the current middle temperature of the reheat heat exchanger as T28, the third temperature difference is the difference between T28 and T2avg.

The opening degree of the reheat throttle adjusting device is adjusted according to the third temperature difference.

Specifically, first compare the third temperature difference with the preset temperature range; if the third temperature difference is within the current preset temperature range; the reheat throttling device performs the adjustment according to the adjustment method corresponding to the current preset temperature range adjust. There are multiple preset temperature ranges, and each preset temperature range has a corresponding opening adjustment method. When the third temperature difference falls within the corresponding preset temperature range, the adjustment method corresponding to the current preset temperature range can be installed and adjusted.

In the heating mode, in order to avoid mutual interference due to the simultaneous adjustment of the reheat throttle valve (dehumidification throttle valve) and the liquid intake throttle valve 144, the opening adjustment of the reheat throttle adjustment device 230 is detected; The flow adjustment device 230 is adjusting the opening degree, and does not obtain the superheat degree of the supplemental gas of the liquid intake throttle valve 144; . That is, before adjusting the opening degree of the reheat throttle valve, it is first detected whether the opening degree of the liquid intake throttle valve 144 is being adjusted. Then adjust the opening of the reheat throttle valve.

It is worth noting that in the heating mode, when there is only one indoor heat exchanger on the indoor side, the throttle valve can be adjusted to the preset opening degree.

When there are multiple indoor heat exchangers on the indoor side, first calculate the average temperature T2avg (target subcooling degree) in the middle of all the heating heat exchangers in the heating mode, and then calculate the temperature in the middle of the indoor heat exchangers running in the current heating mode. The difference between the temperature T2i (heating subcooling degree) and the temperature average T2avg (target subcooling degree) is compared, and the third temperature difference value To (To=T2i-T2avg) obtained by the difference is compared with the preset temperature to determine the third temperature difference Which preset temperature stage the value is in, different temperature stages have different adjustment steps and adjustment methods. It is worth noting that To can be within a certain range.

E.g:

When the third temperature difference is less than the fourth preset temperature, the opening of the throttle valve is greatly opened. To<-3℃, the opening of the electronic expansion valve is opened by 8 steps/120 seconds, that is, the throttle valve is opened every 120 seconds. Open eight steps in a cycle;

-3≤To＜-2℃, the opening of the electronic expansion valve is opened by 4 steps/every 120 seconds, that is, the throttle valve is opened by 4 steps per cycle;

-2≤To≤2℃, the opening of the electronic expansion valve remains unchanged, that is, it is inconvenient to maintain the opening of the throttle valve. At this time, it is considered that the heating subcooling degree is equivalent to the target heating subcooling degree.

2＜To≤3℃, the opening of the electronic expansion valve is reduced by 4 steps/every 120 seconds, that is, the throttle valve is reduced by 4 steps per cycle;

To>3°C, the opening of the electronic expansion valve is reduced by 8 steps/120 seconds, that is, the throttle valve is reduced by 8 steps per cycle.

In some embodiments, in order to avoid the simultaneous opening adjustment of the liquid intake throttle valve 144 and the reheat throttle valve, the adjustment period of the reheat throttle adjustment device 230 and the dehumidification throttle adjustment device is smaller than the liquid intake throttle valve. The adjustment period of the throttle valve 144 . For example, the adjustment period of the reheat throttle valve is 20 seconds, and the adjustment period of the liquid intake throttle valve 144 is 2 minutes, which can fully ensure the heating effect ( The cycle is short, the adjustment is fast, and the operation is accurate), and the enthalpy increasing effect of the enthalpy increasing compressor 110 can be ensured as much as possible, and the heating performance of the compressor 110 can be fully improved.

Control method in constant temperature dehumidification mode:

The control method of the air conditioner includes:

S1000, the indoor unit and the outdoor unit are all in the constant temperature dehumidification mode, and the reheating and subcooling degree of the refrigerant outflow end of the reheating heat exchanger 210 is obtained;

The degree of reheating and subcooling is the difference between the temperature Tb in the middle of the reheating heat exchanger 210 and the temperature Ta at the outlet of the refrigerant flow. The temperature Tb in the middle of the reheat heat exchanger 210 and the temperature Ta of the refrigerant outlet of the reheat heat exchanger 210 during cooling are respectively detected, and the difference between the two is calculated.

S2000, compare the reheat subcooling degree and the reheat target subcooling degree;

The target subcooling degree for reheating is 2 to 15°C, taking 8 to 12°C as an example. Compare the calculated cooling superheat with the cooling target superheat.

S3100. If the reheat subcooling degree is less than the reheat target subcooling degree, reduce the opening degree of the reheat regulating valve;

When the reheating subcooling degree is less than the cooling target superheating degree, it means that the temperature difference between the middle of the reheating heat exchanger 210 and the refrigerant outlet is small, and the temperature difference needs to be increased. At this time, the opening degree of the reheating throttle valve needs to be reduced. to adjust the heat exchange, thereby increasing the temperature difference between the middle of the reheat heat exchanger 210 and the refrigerant outlet. so that the reheat subcooling degree is within the range of the reheat target subcooling degree. At this time, the heating efficiency of the reheat heat exchanger 210 can be ensured, so as to ensure the heat exchange efficiency of the refrigerant in the reheat heat exchanger 210 and improve the heating effect. The opening degree of the reheating throttle valve is gradually adjusted, and the reheating subcooling degree and the cooling target superheating degree are calculated and compared every time the adjustment is made, until the reheating subcooling degree falls within the range of the cooling target superheating degree.

In some embodiments, if the reheat subcooling degree is less than the reheat target subcooling degree, the specific steps of reducing the opening degree of the reheat throttling adjustment device 230 include:

If the degree of reheating and subcooling is less than the reheating target subcooling degree;

obtaining the current opening degree of the reheat throttling adjusting device 230, and comparing the current opening degree with the target opening degree range;

In this embodiment, the opening range of the reheat throttle valve is limited, which can be limited by the structure of the reheat throttle valve itself, that is, the limit opening degree and the limit closing degree; The reheat throttle valve can only move within the preset target opening range.

If the current opening degree is greater than the minimum value of the target opening degree range, the opening degree of the reheat throttle adjusting device 230 is decreased. That is, when the current opening degree of the reheat throttle valve has a further reduction space, the opening degree of the reheat throttle valve can be directly reduced.

If the current opening degree is less than or equal to the minimum value of the target opening degree range, adjust the opening degree of the liquid intake throttle valve 144 or adjust the opening degree of the outdoor side throttle adjusting device 142 to increase the degree of reheating and subcooling. That is, when the current opening degree of the reheat throttle valve has no room for further reduction, the current opening degree of the reheat throttle valve is maintained (in some special conditions, the opening degree even needs to be increased to make the reheat throttle valve The opening degree of the valve returns to the target opening degree range), and the temperature and pressure of the refrigerant in the refrigerant pipe are adjusted by adjusting the opening degree of the liquid intake throttle valve 144 or the outdoor throttling adjustment device 142, so as to finally adjust the reheating heat exchange. The purpose of reheating and supercooling of the heater 210 is to ensure the heating effect.

S3200. If the reheating subcooling degree is greater than the reheating target subcooling degree, increase the opening degree of the reheating regulating valve;

When the reheat subcooling degree is greater than the reheating target subcooling degree, it means that the temperature difference between the middle of the reheat heat exchanger 210 and the refrigerant outlet is large, and the temperature difference needs to be reduced. At this time, the opening of the reheat throttle valve needs to be increased. to adjust the heat exchange, thereby reducing the temperature difference between the middle of the reheat heat exchanger 210 and the refrigerant outlet. so that the reheat subcooling degree is within the range of the reheat target subcooling degree. At this time, the heating efficiency of the reheat heat exchanger 210 can be ensured, so as to ensure the heat exchange efficiency of the refrigerant in the reheat heat exchanger 210 and improve the heating effect.

In some embodiments, if the reheat subcooling degree is greater than the reheat target subcooling degree, the specific steps of increasing the opening degree of the reheat throttling adjustment device 230 include:

If the degree of reheating and supercooling is greater than the reheating target degree of subcooling;

obtaining the current opening degree of the reheat throttling adjusting device 230, and comparing the current opening degree with the target opening degree range;

If the current opening degree is smaller than the maximum value of the target opening degree range, the opening degree of the reheat throttle adjusting device 230 is increased. That is, when the current opening degree of the reheat throttle valve has further room for increase, the opening degree of the reheat throttle valve can be directly increased.

If the current opening degree is greater than or equal to the maximum value of the target opening degree range, the opening degree of the liquid intake throttle valve 144 or the outdoor side throttle adjustment device is adjusted to reduce the degree of reheating and subcooling. That is, when the current opening degree of the reheat throttle valve does not have room for further increase, the current opening degree of the reheat throttle valve should be maintained (in some special conditions, the opening degree may even need to be reduced, so that the reheat throttle valve can The opening of the flow valve returns to the target opening range), and the temperature and pressure of the refrigerant in the refrigerant pipe are adjusted by adjusting the opening of the liquid intake throttling valve 144 or the outdoor side throttling adjustment device, so as to finally adjust the reheat exchange. The purpose of the reheating and subcooling of the heater 210 is to ensure the reheating effect.

S3300. If the reheat subcooling degree is equal to the reheat target subcooling degree, keep the opening degree of the reheat regulating valve.

When the reheat subcooling degree is within the reheat target subcooling degree range, the temperature difference of the reheat heat exchanger 210 is appropriate, which can effectively ensure the condensation efficiency of the reheat heat exchanger 210, so as to ensure the reheating efficiency of the reheat heat exchanger 210. thermal effect.

In the constant temperature dehumidification mode, the control method of the air conditioner also includes:

Obtain the dehumidification and refrigeration superheat degree of the refrigerant flow outlet of the dehumidification heat exchanger 220;

Compare dehumidification cooling superheat and dehumidification cooling target superheat;

If the dehumidification refrigeration superheat degree is greater than the dehumidification refrigeration target superheat degree, increase the opening degree of the dehumidification throttling adjustment device 240;

If the dehumidification refrigeration superheat degree is less than the dehumidification refrigeration target superheat degree, reduce the opening degree of the dehumidification throttling adjustment device 240;

If the dehumidification and cooling superheat degree is equal to the dehumidification and cooling target superheat degree, the opening degree of the dehumidification and throttling adjustment device 240 is maintained.

It is worth noting that the dehumidification cooling superheat degree of the dehumidification heat exchanger 220 in the constant temperature dehumidification mode and the dehumidification cooling superheat degree of the dehumidification heat exchanger 220 in the cooling mode are different. The adjustment of the throttle valve is also affected by the liquid intake throttle valve 144 and the reheat throttle valve. Therefore, the simultaneous adjustment of the dehumidification throttle valve and the liquid intake throttle valve 144 or the reheat throttle valve should be avoided as much as possible.

Avoid simultaneous adjustment of reheat throttle and dehumidification throttle:

Before the step of obtaining the reheating and subcooling degree of the refrigerant outflow end of the reheating heat exchanger 210, the following steps are further included:

Detecting the adjustment of the opening degree of the dehumidification throttling adjustment device 240;

If the opening degree adjustment of the dehumidification and throttling adjustment device 240 is being performed, the reheat and supercooling degree of the refrigerant outflow end of the reheat heat exchanger 210 is not obtained;

If the opening degree of the dehumidification and throttling adjusting device 240 is not adjusted, the degree of reheating and subcooling at the refrigerant outflow end of the reheating heat exchanger 210 is obtained.

In this way, the air conditioner can quickly and reliably adjust the opening of the dehumidifying throttle valve and the reheating throttle valve, avoid mutual interference, and effectively ensure the dehumidification effect of the dehumidifying heat exchanger 220 and the reheating heat exchanger. The reheating effect of 210 ensures the constant temperature and dehumidification effect of the air conditioner.

Avoid simultaneous adjustment of the reheat throttle valve and the intake throttle valve 144:

Before the step of obtaining the reheating and subcooling degree of the refrigerant outflow end of the reheating heat exchanger 210, the following steps are further included:

Detect the adjustment of the opening degree of the liquid taking throttle valve 144;

If the opening of the liquid taking throttle valve 144 is being adjusted, the reheating and subcooling degree of the refrigerant outflow end of the reheating heat exchanger 210 is not obtained;

If the opening degree of the liquid intake throttle valve 144 is not adjusted, the degree of reheating and subcooling at the refrigerant outflow end of the reheating heat exchanger 210 is obtained.

In this way, the air conditioner can quickly and reliably adjust the opening of the liquid intake throttle valve 144 and the reheat throttle valve, avoiding mutual interference, which can effectively ensure the elimination of abnormal noise and ensure the The reheating effect of the heat exchanger 210.

The following describes a control method in which a plurality of indoor units 200 are installed on the indoor side.

A control method for an air conditioner, comprising:

A: Obtain the required cooling or heat of each heat exchanger of the indoor unit 200;

The air conditioner includes a plurality of indoor units 200, and each indoor unit 200 includes a different number of heat exchangers. The heat exchangers can cool or heat. The working conditions of each indoor heat exchanger are set according to user requirements. Therefore, the operation mode and required energy of the heat exchanger on the indoor side can be different. The amount of cooling or heat required depends on the operating parameters set by the user.

B: Calculate the total cooling demand and total heat demand of the indoor unit 200 according to the cooling or heat required by each heat exchanger;

Add the heat required by all the heating heat exchangers to obtain the total heat demand; add the cooling capacity required by all the cooling heat exchangers to obtain the total cooling demand.

C: Adjust the operating parameters of the compressor according to the total demand for cooling and total heat.

Specifically, the step of adjusting the operating parameters of the compressor according to the total cooling demand and the total heating demand includes:

C1: Compare the total cooling demand and the total heating demand; that is, compare the total cooling demand with the total heating demand. There are three comparison results. The total cooling demand is greater than the total heating demand, and the total cooling demand is less than the total heating demand. , and the total cooling demand equals the total heating demand.

C2: If the total demand for cooling is greater than the total demand for heat, the compressor adjusts the operating frequency of the compressor according to the evaporation temperature of the low-pressure suction port; this step specifically includes:

If the total cooling demand is greater than the total heating demand;

Detecting the current working state of the outdoor unit 100;

If the outdoor unit 100 is in the heating state, switch to the cooling state or the constant temperature dehumidification state; if it is in the cooling state or the constant temperature dehumidification state, continue to maintain;

The compressor adjusts the operating frequency of the compressor according to the evaporating temperature of the low pressure suction port.

In this embodiment, when the total demand for cooling is greater than the total demand for heat, the compressor needs to provide cooling for the indoor side. The cooling mode and the constant temperature dehumidification mode can be used to provide cooling. Therefore, it is necessary to confirm the current operation at this time. model. First, it is necessary to detect the current operation state of the outdoor unit 100 of the air conditioner. If the outdoor unit 100 is in the heating state, switch to the cooling state or the constant temperature dehumidification state; if it is the cooling state or the constant temperature dehumidification state, continue to maintain. On this basis, the greater the total cooling demand is greater than the total heat demand, the more cooling energy the outdoor unit 100 needs to provide; the greater the total cooling demand and the total heat demand, the higher the frequency at which the compressor needs to operate Similarly, the smaller the total cooling demand is greater than the total heat demand, the less cooling energy the outdoor unit 100 needs to provide; the smaller the total cooling demand and the total heat demand, the lower the compressor operating frequency needs to be.

C3: If the total cooling demand is less than the total heating demand, the compressor adjusts the operating frequency of the compressor according to the condensing temperature of the high-pressure exhaust port.

If the total demand for cooling is less than the total demand for heat, the step of the compressor adjusting the operating frequency of the compressor according to the condensation temperature of the high-pressure exhaust port specifically includes:

If the total cooling demand is less than the total heating demand;

Detecting the current working state of the outdoor unit 100;

If the outdoor unit 100 is in the cooling state or the constant temperature dehumidification state, switch to the heating state; if it is in the heating state, continue to keep it;

The compressor adjusts the operating frequency of the compressor according to the evaporating temperature of the low pressure suction port.

In this embodiment, when the total cooling demand is less than the total heating demand, the compressor needs to provide heat for the indoor side, and the heat supply mode includes the heating mode. Therefore, the current operation mode needs to be confirmed at this time. First, it is necessary to detect the current operating state of the outdoor unit 100 of the air conditioner. If the outdoor unit 100 is in a cooling state or a constant temperature and dehumidification state, switch to a heating state; if it is in a heating state, keep it. On this basis, the greater the total heat demand is greater than the total cooling demand, the more heat energy the outdoor unit 100 needs to provide; the greater the total cooling demand and the total heat demand, the higher the frequency of compressor operation is required; Similarly, the less the total heat demand is greater than the total cooling demand, the less heat energy the outdoor unit 100 needs to provide; the smaller the total cooling demand and the total heat demand, the lower the compressor operating frequency needs to be.

In some embodiments, the exhaust pipe 111 is provided with a fifth control valve 330, and the step of adjusting the operating parameters of the compressor according to the total cooling demand and the total heating demand further includes:

C4: If the total cooling demand is equal to the total heating demand, the fifth control valve 330 is closed. If the total cooling demand is equal to the total heating demand, at this time, the outdoor unit 100 does not need to provide cooling energy and heating energy for the indoor side. Therefore, the refrigerant at this time may not pass through the outdoor heat exchanger. By closing the fifth control valve 330 , the phenomenon that the refrigerant flow backflow and the excessive accumulation of refrigerant in the outdoor unit 100 and the insufficient circulating refrigerant amount can be avoided. In some embodiments, the third control valve 310 may also be closed.

In this embodiment, by first obtaining the cooling capacity or heat required by each heat exchanger of the indoor unit 200; and then calculating the total cooling capacity and the total cooling capacity of the indoor unit 200 according to the cooling capacity or heat required by each heat exchanger. The total heat demand; then, the operating parameters of the compressor are adjusted according to the total cooling demand and the total heat demand; so that the heat exchangers on the indoor side are guided by the pressure difference to transfer and exchange energy to achieve heat recovery or heat recovery. Partial recycling; while providing users with personalized services, the utilization rate of energy is fully improved.

The above descriptions are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformations made by the contents of the description and drawings of the present invention, or the direct/indirect application Other related technical fields are included in the scope of patent protection of the present invention.

Claims (12)

1. The control method of the air conditioner is characterized by comprising an outdoor unit and an indoor unit, wherein the outdoor unit comprises a compression mechanism and an outdoor heat exchanger, and the indoor unit comprises a dehumidification heat exchanger and a dehumidification throttling regulation device;

the air conditioner further includes: a discharge pipe connected to a discharge side of the compression mechanism, a low-pressure suction pipe connected to a low-pressure suction side of the compression mechanism, a liquid-side piping connecting the discharge pipe, the outdoor heat exchanger, the dehumidification throttle control device, and the dehumidification heat exchanger in this order, and a gas-side piping connecting the dehumidification heat exchanger and the low-pressure suction pipe, thereby constituting a dehumidification circuit;

the indoor unit also comprises a reheating heat exchanger, a reheating throttling regulation device and a heat circulation device for sending the heat or cold of the indoor unit into the room;

the air conditioner further includes a high-low pressure pipe and a branch pipe branching from the discharge pipe, the high-low pressure pipe sequentially connecting a first intersection of the liquid-side pipe, the reheat throttle control device, the reheat heat exchanger, and the branch pipe to constitute a reheat circuit, wherein the first intersection is located between the dehumidification throttle control device and the outdoor heat exchanger; the air conditioner further includes a second switch switchable between a third switching state in which the second switch communicates the high-and low-pressure piping with the branch pipe and a fourth switching state in which the second switch communicates the high-and low-pressure piping with the suction pipe;

the control method of the air conditioner comprises the following steps:

under the constant temperature dehumidification of the outdoor unit and the refrigeration mode of the indoor unit, the refrigeration superheat degree of a refrigerant inflow end of a liquid side piping is obtained;

comparing the refrigerating superheat degree with a refrigerating target superheat degree;

if the refrigerating superheat degree is smaller than the refrigerating target superheat degree, reducing the opening degree of a reheating regulating valve;

if the refrigerating superheat degree is larger than the refrigerating target superheat degree, the opening degree of a reheating regulating valve is increased;

and if the refrigerating superheat degree is equal to the target refrigerating superheat degree, keeping the opening degree of the reheating regulating valve.

2. The control method of an air conditioner according to claim 1,

the air conditioner also comprises a gas-liquid separator and an economizer, wherein the gas-liquid separator is arranged on the low-pressure suction pipe; the economizer is arranged on a liquid side pipe between the outdoor heat exchanger and the first intersection point, and a return pipe of the economizer is communicated with the gas-liquid separator; the economizer is internally provided with a first refrigerant flow path and a second refrigerant flow path, and two ends of the first refrigerant flow path are respectively communicated with liquid side distribution pipes at two ends of the economizer; one end of the second refrigerant flow path is communicated with the liquid side pipe through a liquid taking pipe, and the other end of the second refrigerant flow path is communicated with a medium-pressure suction inlet of the compressor through a return pipe; a liquid taking regulating valve is arranged on the liquid taking pipe;

if the refrigerating superheat degree is larger than the refrigerating target superheat degree, the specific step of increasing the opening degree of the reheating throttling adjusting device comprises the following steps:

if the refrigerating superheat degree is larger than the refrigerating target superheat degree;

acquiring the current opening degree of the reheating throttling adjusting device, and comparing the current opening degree with a target opening degree range;

and if the current opening degree is smaller than the maximum value of the target opening degree range, increasing the opening degree of the reheating throttle adjusting device.

3. The control method of an air conditioner according to claim 2, further comprising, after the step of obtaining a current opening degree of the reheat throttle adjusting means, and comparing the current opening degree with a target opening degree range:

and if the current opening is larger than or equal to the maximum value of the target opening range, adjusting the opening of the liquid-taking throttle valve to reduce the refrigeration superheat degree.

4. The control method of an air conditioner according to claim 2, wherein if the degree of superheat of cooling is less than the target degree of superheat of cooling, the concrete step of reducing the opening degree of the reheat throttle adjusting means includes:

if the refrigerating superheat degree is less than the refrigerating target superheat degree;

acquiring the current opening degree of the reheating throttling adjusting device, and comparing the current opening degree with a target opening degree range;

and if the current opening degree is smaller than the maximum value of the target opening degree range, reducing the opening degree of the reheating throttle adjusting device.

5. The control method of an air conditioner according to claim 4, further comprising, after the step of obtaining a current opening degree of the reheat throttle adjusting means, and comparing the current opening degree with a target opening degree range:

and if the current opening is larger than or equal to the maximum value of the target opening range, adjusting the opening of the liquid-taking throttle valve to increase the refrigeration superheat degree.

6. The control method of an air conditioner according to claim 2, wherein the return pipe is communicated with the gas-liquid separator through a low pressure suction pipe, and the second control valve is provided on the return pipe or a connection pipe between the return pipe and the low pressure suction pipe.

7. The control method of an air conditioner according to claim 1, wherein the air conditioner further comprises an economizer; the economizer is arranged on a liquid side pipe between the outdoor heat exchanger and the first intersection point, and a return pipe of the economizer is communicated with a medium-pressure suction inlet of the compressor; the economizer is internally provided with a first refrigerant flow path and a second refrigerant flow path, and two ends of the first refrigerant flow path are respectively communicated with liquid side distribution pipes at two ends of the economizer; one end of the second refrigerant flow path is communicated with the liquid side pipe through a liquid taking pipe, and the other end of the second refrigerant flow path is communicated with a medium-pressure suction inlet of the compressor through a return pipe; and a liquid taking regulating valve is arranged on the liquid taking pipe.

8. The control method of an air conditioner according to claim 7, wherein an inflow end of the liquid take-out pipe communicates with a liquid side pipe between the economizer and the outdoor side heat exchanger; or,

the inflow end of the liquid take-off pipe is communicated with a liquid side pipe between the economizer and the first intersection.

9. The control method of an air conditioner according to claim 1,

the outdoor unit further comprises a first switch switchable between a first switch first switching state and a first switch second switching state,

in the first switching state, the first switch communicates the liquid-side pipe with the suction pipe and communicates the gas-side pipe with the discharge pipe,

in the second switching state, the first switch communicates the first pipe with the discharge pipe and communicates the gas-side pipe with the suction pipe.

10. The control method of an air conditioner according to claim 1, wherein the control method of an air conditioner further comprises:

acquiring the dehumidification refrigeration superheat degree of a refrigerant outflow port of a dehumidification heat exchanger;

comparing the dehumidification refrigeration superheat degree with the dehumidification refrigeration target superheat degree;

if the superheat degree of dehumidification refrigeration is smaller than the target superheat degree of dehumidification refrigeration, reducing the opening degree of the dehumidification throttling adjusting device;

if the dehumidification refrigeration superheat degree is larger than the dehumidification refrigeration target superheat degree, the opening degree of the dehumidification throttling adjusting device is increased;

and if the superheat degree of dehumidification refrigeration is equal to the target superheat degree of dehumidification refrigeration, keeping the opening degree of the dehumidification throttling adjusting device.

11. The control method of an air conditioner according to claim 10, wherein the opening degree of the dehumidifying control means and the opening degree of the reheating control means are alternately adjusted.

12. The method as claimed in claim 10, wherein the step of obtaining the superheat of the refrigerant at the refrigerant outflow end of the reheat heat exchanger is preceded by the step of:

detecting the opening degree adjusting condition of the dehumidification throttling adjusting device;

if the dehumidification throttling adjusting device is adjusting the opening degree, the refrigeration superheat degree of the refrigerant outflow end of the reheat heat exchanger is not obtained;

and if the opening degree of the dehumidification throttling adjusting device is not adjusted, the refrigeration superheat degree of the refrigerant outflow end of the reheat heat exchanger is obtained.

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