CN115342425A - Multi-split air conditioner - Google Patents

Abstract

The present invention provides a multi-connected air conditioner. The multi-connected air conditioner includes: an outdoor unit; a plurality of transfer units connected to the outdoor unit through gas pipes and liquid pipes; a plurality of indoor units; The transfer units are connected in one-to-one correspondence; waste heat recovery pipes are arranged between a plurality of transfer units, and are used to recover waste heat between the transfer units. The invention can solve the technical problems of limited distance between the transfer unit and the indoor unit, waste of heat and low efficiency when the multi-connected air conditioner is in operation.

Description

A multi-connected air conditioner

technical field

The invention relates to the technical field of air conditioners, in particular to a multi-connected air conditioner.

Background technique

At this stage, multi-connected air conditioners are widely used. One outdoor unit is connected with two or more indoor units through piping to achieve the purpose of controlling multiple units. In the process, multiple indoor units can be simultaneously cooled, heated and cooled. Simultaneous demand.

At present, although there are multi-connected air conditioners that can cool and heat at the same time, it is necessary to add a relay unit between the outdoor unit and the indoor unit to achieve the purpose of cooling and heating multiple indoor units at the same time. However, the relay unit is a centralized relay unit. That is to say, one transfer unit connects multiple indoor units. If there are more indoor units connected to the transfer unit, the distance between the indoor unit and the transfer unit will increase. When the distance exceeds a certain distance, the cooling or heating efficiency of the indoor unit will be affected. ; Even if the one-to-one connection between the transfer unit and the indoor unit is adopted, there are disadvantages of heat loss and low efficiency.

Contents of the invention

The invention can solve the technical problems of limited distance between the transfer unit and the indoor unit, waste of heat and low efficiency when the multi-connected air conditioner is in operation.

In order to solve the above problems, the present invention provides a multi-connected air conditioner, which includes: an outdoor unit; a plurality of transfer units connected to the outdoor unit through gas pipes and liquid pipes; a plurality of indoor units; The indoor units are connected to the multiple transfer units in one-to-one correspondence; waste heat recovery pipes are arranged between the multiple transfer units to recover waste heat between the transfer units.

Each of the relay units is connected to each of the indoor units in one-to-one correspondence, realizing the purpose of a single relay unit controlling a single indoor unit. Compared with the centralized relay unit, the distance between the relay unit and the indoor unit is avoided. Furthermore, the waste heat recovery pipe can recover the waste heat between the transfer units, avoiding the waste of heat, and effectively improving the use efficiency of the air conditioner.

Further, in one embodiment of the present invention, each of the transfer units includes a gas-liquid separator, and when the outdoor unit is in the main mode of cooling, the high-pressure refrigerant is separated into high-pressure gaseous refrigerant and As for the high-pressure liquid refrigerant, if any one of the indoor units is in the heating mode, the high-pressure gaseous refrigerant is delivered to it, and if any of the indoor units is in the cooling mode, the high-pressure liquid refrigerant is delivered to it.

The setting of the gas-liquid separator can separate the high-pressure refrigerant, so that it can provide high-pressure liquid refrigerant for the indoor unit in the cooling mode, and provide high-pressure gas refrigerant for the indoor unit in the heating mode. The high-pressure gaseous refrigerant realizes the purpose of simultaneous cooling and heating of the multi-connected air conditioner, and improves the cooling or heating efficiency of the air conditioner.

Further, in one embodiment of the present invention, the liquid refrigerant of the indoor unit in the heating mode is transported to the indoor unit in the cooling mode through the waste heat recovery pipe.

Through the arrangement of the waste heat recovery pipe, the high-pressure liquid generated by the indoor unit in the heating mode can be transported to the indoor unit in the cooling mode, achieving the purpose of waste heat recovery between the transfer units. In this mode, The cooling efficiency of the indoor unit in cooling mode is improved.

Further, in one embodiment of the present invention, the gas-liquid separator is arranged between the liquid pipe and the indoor unit, the gas-liquid separator includes an inlet, a gas outlet and an outlet, and the gas-liquid separator in cooling mode The outlet of the gas-liquid separator of the indoor unit communicates with the refrigerant inlet of the indoor unit, and the gas outlet communicates with the air pipe; the outlet of the gas-liquid separator of the indoor unit in the heating mode The waste heat recovery pipe communicates with the refrigerant inlet of the indoor unit in cooling mode; the inlet communicates with the liquid pipe.

The liquid pipe is connected to the inlet of the gas-liquid separator to provide high-pressure refrigerant for the gas-liquid separator, and to provide high-pressure liquid refrigerant or high-pressure gas refrigerant for the indoor unit through the gas-liquid separator to achieve different Heating or cooling of the indoor unit The arrangement of multiple openings of the gas-liquid separator better realizes the full use of heat between different indoor units and improves the heating and cooling effects of the air conditioner.

Further, in one embodiment of the present invention, the refrigerant outlet of the indoor unit in heating mode communicates with the refrigerant inlet of the indoor unit in cooling mode through the waste heat recovery pipe.

The refrigerant outlet of the indoor unit in the heating mode is connected to the refrigerant inlet of the indoor unit in the cooling mode through the waste heat recovery pipe, providing high-pressure refrigerant for the indoor unit in the cooling mode, further The cooling efficiency of the indoor unit in the cooling mode is enhanced.

Further, in one embodiment of the present invention, each of the transfer units includes a jet pump, and when the outdoor unit is in the heating mode, if any of the indoor units is in the heating mode, it will deliver A part of the high-pressure gaseous refrigerant passing through the indoor unit is sent to the liquid pipe; the other part is sent to the transfer unit of the indoor unit in cooling mode through the waste heat recovery pipe.

In another case, when the outdoor unit is in the main mode of heating, high-pressure gaseous refrigerant is provided to the indoor unit in the heating mode, and then the high-pressure liquid refrigerant converted by the indoor unit is delivered to the cooling system. In the indoor unit in the above mode, in this state, the recovery of waste heat between the transfer units is fully realized, the waste of resources is reduced, and the efficiency of the air conditioner is improved.

Further, in one embodiment of the present invention, a part of the high-pressure liquid refrigerant delivered by the waste heat recovery pipe to the transfer unit of the indoor unit in the cooling mode is delivered to the indoor unit in the cooling mode; the other part is delivered to the indoor unit in the cooling mode. In the jet pump; wherein, the high-pressure liquid refrigerant delivered to the jet pump is used to drain the low-pressure gas refrigerant generated by the indoor unit in cooling mode.

The indoor unit in the cooling mode converts the high-pressure liquid refrigerant into a low-pressure gaseous refrigerant, and the low-pressure gaseous refrigerant is boosted by the jet pump and then delivered to the liquid pipe. During this process, all The low-pressure gaseous refrigerant is mixed with part of the high-pressure liquid refrigerant in the waste heat recovery pipe, which avoids the need to increase the diameter of the pipe due to the delivery of the low-pressure gaseous refrigerant, thereby reducing the specification requirements of the pipe and saving materials.

Further, in one embodiment of the present invention, each of the transfer units further includes a gas-liquid separator, the gas-liquid separator is arranged between the liquid pipe and the indoor unit, and the gas-liquid separator The device includes an inlet, a gas outlet and an outlet.

The setting of the gas-liquid separator further enhances the mixing between the liquid refrigerant and the gas refrigerant and can be used as a liquid storage chamber for the mixed fluid at this time, which improves the efficiency of the air conditioner and further strengthens the low-pressure gas refrigerant inside the pipeline. Mixing of high-pressure liquid refrigerants.

Further, in one embodiment of the present invention, when the outdoor unit is in the main mode of heating, the refrigerant outlet of the indoor unit in the heating mode communicates with the inlet; the refrigerant outlet of the indoor unit in the cooling mode The jet pump communicates with the inlet; the outlet communicates with the liquid pipe.

The expansion loss can be recovered through the jet pump, and the beneficial effect of not transporting low-pressure gaseous refrigerant is achieved when heating is the main mode.

Further, in one embodiment of the present invention, the jet pump is provided with: a drive inlet, a suction inlet, and an outlet of the jet pump; when the outdoor unit is in the main mode of heating, the indoor unit in the cooling mode The outlet of the refrigerant is connected to the suction inlet; the driving inlet is connected to the waste heat recovery pipe, and the outlet of the jet pump is connected to the inlet of the gas-liquid separator.

Through the driving inlet and the suction inlet, the high-pressure liquid refrigerant and the low-pressure gaseous refrigerant can be mixed inside the jet pump, and the mixed fluid is further pressurized, and finally transported from the outlet of the jet pump to The liquid pipe, in this process, through the absorption treatment of the low-pressure gaseous refrigerant, realizes the purpose of conveying the fluid without increasing the diameter of the pipe, and saves costs.

In summary, after adopting the technical solution of the present invention, the following technical effects can be achieved:

i) Each of the transfer units is connected to a single indoor unit, which avoids the limitation of the distance between the indoor unit and the transfer unit;

ii) The arrangement of the waste heat recovery pipe can realize the recovery of waste heat between the transfer units, further improving the cooling or heating efficiency of the indoor unit;

iii) The arrangement of the gas-liquid separator improves the separation of gaseous refrigerant and liquid refrigerant;

iv) The arrangement of the jet pump avoids the requirement of increasing the diameter of the delivery pipe due to the delivery of low-pressure gaseous refrigerant when heating is the main mode, further saving costs.

Description of drawings:

Fig. 1 is a schematic structural diagram of a multi-connected air conditioner 100 according to a first embodiment of the present invention.

FIG. 2 is a flow diagram of refrigerant when the first indoor unit 30 and the second indoor unit 50 shown in FIG. 1 are cooling simultaneously.

FIG. 3 is a flow diagram of refrigerant when the first indoor unit 30 and the second indoor unit 50 shown in FIG. 1 are simultaneously heating.

FIG. 4 is a flow diagram of refrigerant when the first indoor unit 30 shown in FIG. 1 is cooling and the second indoor unit 50 is heating.

FIG. 5 is a flow diagram of refrigerant when the first indoor unit 30 shown in FIG. 1 is heating and the second indoor unit 50 is cooling.

FIG. 6 is a schematic structural diagram of the jet pump 42 in FIG. 5 .

Explanation of reference signs:

100-multi-split air conditioner; 10-outdoor unit; 11-accumulator; 12-compressor; 13-four-way valve; 14-first heat exchanger; 15-outdoor expansion valve; 20-first transfer unit; 21 - the first gas-liquid separator; 22 - the first injection pump; 23 - the first check valve; 24 - the second check valve; 25 - the first solenoid valve; 26 - the second solenoid valve; 27 - the first expansion Valve; 28-second expansion valve; 30-first indoor unit; 31-second heat exchanger; 32-first indoor expansion valve; 40-second transfer unit; 41-second gas-liquid separator; 411- Gas chamber; 412-liquid chamber; 42-second jet pump; 421-mixing part; 422-second compressor; 423-condenser; 424-evaporator; 43-third check valve; 44-fourth Check valve; 45-the third solenoid valve; 46-the fourth solenoid valve; 47-the third expansion valve; 48-the fourth expansion valve; 50-the second indoor unit; 51-the third heat exchanger; 52-the first Two indoor expansion valves; 60-gas pipe; 70-liquid pipe; 80-waste heat recovery pipe.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

【The first embodiment】

The embodiment of the present invention provides a multi-connected air conditioner 100, the multi-connected air conditioner 100 includes: an outdoor unit 10, a plurality of transfer units and a plurality of indoor units; 70 is connected to the outdoor unit 10; a plurality of the indoor units; a plurality of the indoor units are connected to a plurality of the transfer units in one-to-one correspondence.

Preferably, taking the transfer unit and the indoor unit as an example, referring to Figures 1-3, the transfer unit includes: a first transfer unit 20 and a second transfer unit 40; the indoor unit includes: The first indoor unit 30 and the second indoor unit 50; wherein, the first transfer unit 20 and the second transfer unit 40 are connected to the outdoor unit 10 through the air pipe 60 and the liquid pipe 70; the first indoor unit 30 is connected to the first transfer unit 20 , the second indoor unit 50 is connected to the second relay unit; the outdoor unit 10 includes an accumulator 11 , a compressor 12 , a four-way valve 13 , a first heat exchanger 14 and an outdoor expansion valve 15 connected in sequence by piping.

Preferably, the first transfer unit 20 and the second transfer unit 40 are provided with a pipe 90 inside, and the setting of the pipe 90 realizes the communication between the first indoor unit 30, the second indoor unit 50 and the outdoor unit 10, and further the outdoor unit 10 realizes the effect of heating and cooling on the first indoor unit 30 and the second indoor unit 50 through the pipe 90 .

Specifically, the pipeline 90 includes: a first pipeline 91, a second pipeline 92, a third pipeline 93, and a fourth pipeline 94; wherein, the first pipeline 91 and the second pipeline 92 are arranged in the first transfer unit 20, and the first pipeline One end of 91 is connected to the air pipe 60, the second pipe 92 is connected to the liquid pipe 70, the first indoor unit 30 is connected between the first pipe 91 and the second pipe 92; the third pipe 93 and the fourth pipe 94 are arranged in the second transit Unit 40, and the third pipeline 93 is connected to the gas pipe 60, the fourth pipeline 94 is connected to the liquid pipe 70, and the second indoor unit 50 is connected between the third pipeline 93 and the fourth pipeline 94; it can be understood that the first transit The internal structure of the unit 20 is consistent with that of the second transfer unit 40 ; the multi-split air conditioner 100 also includes: a waste heat recovery pipe 80 connected between the second pipe 92 and the fourth pipe 94 .

Preferably, when there are two transfer units, the gas-liquid separator includes: a first gas-liquid separator 21 and a second gas-liquid separator 41; wherein, the first gas-liquid separator 21 is arranged on the first The transfer unit 20, the second gas-liquid separator 41 is arranged on the second transfer unit 40; the further first transfer unit 20 also includes: the first jet pump 22; the first gas-liquid separator 21 is arranged on the second pipeline 92, And it is located between the waste heat recovery pipe 80 and the liquid pipe 70; the first jet pump 22 is arranged between the first pipe 91 and the second pipe 92; further, the first transfer unit 20 is also provided with a first expansion valve 27, The second expansion valve 28 , the first solenoid valve 25 and the second solenoid valve 26 are used to control the flow of refrigerant in the first transfer unit 20 .

Further, the first transfer unit 20 is also provided with a first check valve 23 and a second check valve 24, which are respectively arranged on the first pipeline 91 and the first jet pump 22, and the second pipeline 92 and the first jet pump 22. used to control the flow of refrigerant inside the first transfer unit 20 between the first pipeline 91, the second pipeline 92 and the first injection pump 22, and the first check valve 23 and the second check valve 24 are set in the opposite direction.

Still further, the first indoor unit 30 is provided with a second heat exchanger 31, the second indoor unit 50 is provided with a third heat exchanger 51, and the second pipe 92 connected to the second heat exchanger 31 is provided with a first An indoor expansion valve 32 , the second indoor expansion valve 52 is arranged on the fourth pipe 94 connected to the second heat exchanger 51 .

Preferably, the structure and connection relationship of the second indoor unit 50 and the second relay unit 40 are consistent with those of the first indoor unit 30 and the first relay unit 20 , which will not be repeated here.

Preferably, when the first indoor unit 30 and the second indoor unit 50 are cooling at the same time, the outdoor unit 10 sends high-pressure liquid refrigerant to the first indoor unit 30 and the second indoor unit 40 through the liquid pipe 70, specifically, the liquid pipe 70 After the high-pressure liquid refrigerant is transported to the second pipeline 92 and the fourth pipeline 94 of the first transfer unit 20 and the second transfer unit 40, the high-pressure liquid refrigerant is transferred by the first indoor expansion valve 32 and the second indoor expansion valve 52 It is converted into a low-temperature and low-pressure two-phase refrigerant that is easy to evaporate, wherein the low-pressure two-phase refrigerant includes a low-pressure liquid refrigerant and a low-pressure gaseous refrigerant; further, the low-pressure two-phase refrigerant passes through the second heat exchanger 31 and the third heat exchanger 31. The heat exchanger 51 completes the heat exchange to realize the cooling effect of the first indoor unit 30 and the second indoor unit 50; the low-pressure gaseous refrigerant produced by the heat exchange between the second heat exchanger 31 and the third heat exchanger 51 is then passed through the first pipeline 91 and the third pipeline 93 to the air pipe 60, and further, to the outdoor unit 10; wherein, A is a high-pressure gaseous refrigerant, B is a high-pressure liquid refrigerant, C is a low-pressure two-phase refrigerant, D is a low-pressure gaseous refrigerant, and E is a high-pressure two-phase refrigerant. phase refrigerant.

Furthermore, during the cooling process of the first indoor unit 30 and the second indoor unit 50 at the same time, the first solenoid valve 25 and the first expansion valve 27 in the first transfer unit 20 are in an open state, and the second expansion valve 28 And the second solenoid valve 26 is in the closed state; similarly, in the second transfer unit 40, the third solenoid valve 45 and the third expansion valve 47 are in the open state, and the fourth solenoid valve 46 and the fourth expansion valve 48 are in the closed state .

It can be understood that, during the cooling process of the first indoor unit 30 and the second indoor unit 50 at the same time, the operating states of the first indoor unit 30 and the second indoor unit 50 are consistent, so at this time, the first transfer unit 30 and the second indoor unit 50 The jet pump and the gas-liquid separator in the second transfer unit 50 do not have a working state. During the simultaneous cooling process, the operation process of the multi-connected air conditioner 100 is consistent with that of the connected air conditioner in the prior art. The specific operation process will not be described here. repeat.

Preferably, the principle of simultaneous heating and cooling of the first indoor unit 30 and the second indoor unit 50 is consistent. The first indoor unit 30 and the second indoor unit 40 deliver high-pressure gaseous refrigerant; specifically, after the high-pressure gaseous refrigerant in the air pipe 60 is delivered to the first pipeline 91 and the third pipeline 93 of the first transfer unit 20 and the second transfer unit 40, The heat exchange is completed through the second heat exchanger 31 and the third heat exchanger 51. After the heat exchange is completed, the generated high-pressure liquid refrigerant is transported to the liquid pipe 70 through the second pipeline 92 and the fourth pipeline 94, and further The liquid pipe 70 is sent back to the outdoor unit 10 .

Further, during simultaneous heating and simultaneous cooling, except that the gas-liquid flow direction between the first indoor unit 30, the second indoor unit 50, and the outdoor unit 10 is opposite, each switch in the first transfer unit 20 and the second transfer unit 40 The closed state of is also consistent with that under simultaneous cooling conditions, and will not be repeated here.

【Second Embodiment】

Preferably, the second embodiment of the present invention provides another multi-connected air conditioner 100. When the outdoor unit 10 is in the main mode of cooling, the high-pressure refrigerant is separated into a high-pressure gaseous refrigerant and a high-pressure liquid refrigerant through the gas-liquid separator. When one of the indoor units is in the heating mode, high-pressure gaseous refrigerant is delivered to it; if any of the indoor units is in cooling mode, high-pressure liquid refrigerant is delivered to it. The liquid refrigerant of the indoor unit in the heating mode is delivered to the indoor unit in the cooling mode through the waste heat recovery pipe 80 . The gas-liquid separator is arranged between the liquid pipe 70 and the indoor unit, the gas-liquid separator includes an inlet, a gas outlet and an outlet, and the outlet of the gas-liquid separator of the indoor unit in cooling mode It communicates with the refrigerant inlet of the indoor unit, and the gas outlet communicates with the gas pipe 60; the gas outlet of the gas-liquid separator of the indoor unit in heating mode communicates with the refrigerant inlet of the indoor unit, and the outlet The refrigerant inlet of the indoor unit in the cooling mode is communicated through the waste heat recovery pipe 80; the inlet is communicated with the liquid pipe 70; The refrigerant inlet of the indoor unit is connected.

Wherein, the main mode of cooling means that: when the multi-split air conditioner 100 is running at the same time of cooling and heating, referring to FIG. The multi-connected air conditioner 100 is mainly based on cooling, that is, at this time, the operating state of the multi-connected air conditioner 100 can be recorded as: cooling is the main mode, and in this state, the outdoor unit 10 is heating; In the main mode, the second indoor unit 50 can be regarded as the second outdoor unit of the first indoor unit 30, through the cooperation between the second indoor unit 50 and the outdoor unit 10, through the liquid pipe 70 and the waste heat recovery pipe 80 to the first The high-pressure liquid refrigerant delivered by the first indoor unit 30 improves the cooling efficiency of the first indoor unit 30 and further satisfies the user's demand for cooling in the cooling-based mode.

Further, when there are two indoor units and two transfer units, when the multi-connected air conditioner 100 is heating and cooling at the same time, in the cooling mode of the outdoor unit 10, the first indoor unit 30 is used for cooling, and the second indoor unit 30 is used for cooling. Take machine 50 heating as an example;

Referring to Fig. 4, in the main mode of cooling, by suppressing the air volume of the fan of the first heat exchanger 14 in the outdoor unit 10, it can generate high-pressure two-phase refrigerant in the piping of the outdoor unit 10, that is, high-pressure gaseous refrigerant and The high-pressure liquid refrigerant exists at the same time, and the high-pressure two-phase refrigerant is transported from the second pipeline 92 to the first gas-liquid separator 21 through the liquid pipe 70. After the gas-liquid separation is performed by the first gas-liquid separator 21, the high-pressure liquid refrigerant It is transported to the first indoor unit 30 by the first expansion valve 27, and after the first indoor expansion valve 32 performs depressurization treatment, a low-pressure two-phase refrigerant is generated, and then enters the second heat exchanger 31, thereby realizing the first indoor unit 30 for the purpose of cooling, the low-pressure gaseous refrigerant after further heat exchange by the second heat exchanger 31 is transported to the gas pipe 60 by the first pipeline 91, and finally transported back to the interior of the outdoor unit 10, thereby forming a cycle.

Furthermore, during the cooling process of the first indoor unit 30, the first solenoid valve 25 in the first relay unit 20 is in an open state, the second solenoid valve 26 is in a closed state, the first expansion valve 27 is in an open state, and the second expansion valve 27 is in an open state. The valve 28 is in an open state and the valve opening of the second expansion valve 28 is adjusted to be small, so that it can reduce the pressure of the high-pressure gaseous refrigerant flowing from the first gas-liquid separator 21 to the first pipeline 91, and further cooperate with the second expansion valve 28. The low-pressure gaseous refrigerant in a pipeline 91 is mixed and sent to the outdoor unit 10 through the air pipe 60 together.

Preferably, when the second indoor unit 50 is heating, the high-pressure two-phase refrigerant in the liquid pipe 70 is transported to the second gas-liquid separator 41 through the fourth pipe 94, and then undergoes gas-liquid separation, and the high-pressure gaseous refrigerant passes through the fourth The expansion valve 48 is transported to the third pipeline 93, and further transported to the second indoor unit 50 for heat exchange. After the heat exchange is completed by the third heat exchanger 51, a high-pressure liquid refrigerant is formed; Full utilization of liquid refrigerant, the high-pressure liquid refrigerant can be transported to the first indoor unit 30 through the waste heat recovery pipe 80, and further refrigerated by the first indoor unit 30; the high-pressure liquid refrigerant separated by the second gas-liquid separator 41 It can be sent to the waste heat recovery pipe 80 by the third expansion valve 47, mixed with the high-pressure liquid refrigerant generated by the second indoor unit 50, and then sent to the first indoor unit 30. During this process, the second indoor unit 50 is prevented from being The waste of high-pressure liquid refrigerant generated during heating.

Further, during the heating process of the second indoor unit 50, the third solenoid valve 45 and the fourth solenoid valve 46 are in a closed state, and the fourth expansion valve 48 is in a fully open state; in order to prevent the separation of the second gas-liquid separator 41 The high-pressure liquid refrigerant affects the heating of the second indoor unit 50, so the opening of the third expansion valve 47 is adjusted to be small.

Preferably, in one case, when cooling is the main mode and the requirement for heating is relatively low, the first gas-liquid separator 21 and the first gas-liquid separator 21 in the first transfer unit 20 and the second transfer unit 40 can also be omitted. Two gas-liquid separators 41. The high-pressure liquid refrigerant (for example, condensing temperature of 50°C) from the outdoor unit 10 can flow into the first indoor unit 30 and the second indoor unit 50, and only sensible heat is used for heating, that is, when the second indoor unit 50 is heating , the temperature of the high-pressure liquid refrigerant is used for heating, and the state of the refrigerant does not undergo a phase change during the process.

[Third embodiment]

Preferably, the third embodiment of the present invention provides another multi-connected air conditioner 100. In the embodiment of the present invention, each of the transfer units includes a jet pump, and when the outdoor unit 10 is in the main mode of heating, if any When the indoor unit is in the heating mode, high-pressure gaseous refrigerant is delivered to it, and a part of the high-pressure liquid refrigerant passing through the indoor unit is delivered to the liquid pipe; the other part is delivered to the indoor unit in cooling mode through the waste heat recovery pipe 80 the transfer unit. A part of the high-pressure liquid refrigerant delivered by the waste heat recovery pipe 80 to the transfer unit of the indoor unit in the cooling mode is delivered to the indoor unit in the cooling mode; the other part is delivered to the jet pump; The high-pressure liquid refrigerant in the pump is used to drain the low-pressure gas refrigerant generated by the indoor unit in cooling mode. When the outdoor unit 10 is in the main mode of heating, the refrigerant outlet of the indoor unit in the heating mode communicates with the inlet of the gas-liquid separator; the refrigerant outlet of the indoor unit in the cooling mode communicates with the inlet of the gas-liquid separator through the jet pump. The inlet is communicated; the outlet of the gas-liquid separator is communicated with the liquid pipe. The jet pump is provided with: a driving inlet, a suction inlet, and an outlet of the jet pump; when the outdoor unit 10 is in the heating mode, the refrigerant outlet of the indoor unit in the cooling mode communicates with the suction inlet; The driving inlet is communicated with the waste heat recovery pipe 80; the outlet of the jet pump is communicated with the inlet of the gas-liquid separator.

Among them, the main mode of heating means: when the multi-split air conditioner 100 is running at the same time for cooling and heating, refer to FIG. The multi-connected air conditioner 100 mainly focuses on heating, that is, the operating state of the multi-connected air conditioner 100 can be recorded as: heating is the main mode, and in this state, the outdoor unit 10 is cooling; In the heat-based mode, the user’s demand for cooling is relatively low, and the first indoor unit 30 can be used as the outdoor unit of the second indoor unit 50, and the first indoor unit 30 can provide the high-pressure liquid refrigerant required by the second indoor unit 50, At this time, the waste heat recovery pipe 80 mainly plays the role of delivering high-pressure liquid refrigerant to the second indoor unit 50 .

Further, referring to Fig. 5, when there are two indoor units and two transfer units, when heating is the main mode, take the first indoor unit 30 for heating and the second indoor unit 50 for cooling as an example: the outdoor unit 10 The high-pressure gaseous refrigerant is delivered from the first pipe 91 to the first indoor unit 30 through the gas pipe 60, and the high-pressure liquid refrigerant is formed after the heat exchange between the second heat exchanger 31 and the indoor air, wherein a part of the generated high-pressure liquid refrigerant The second pipe 92 is sent to the liquid pipe 70 through the first expansion valve 27, and then sent back to the outdoor unit 10 by the liquid pipe 70 to form a cycle; the other part of the generated high-pressure liquid refrigerant is passed through the second pipe 92 through the waste heat recovery pipe 80 After being transported to the second transfer unit 40, the pressure is further reduced through the second indoor expansion valve 52, and after heat exchange is performed by the third heat exchanger 51, the third pipeline 93 passes through the third check valve 42, the second The jet pump 42, the fourth electromagnetic valve 46, the second gas-liquid separator 41 and the liquid pipe 70 are sent back to the outdoor unit 10 to complete the cycle; at the same time, the high-pressure liquid refrigerant sent to the second transfer unit 40 in the second pipe 92 The other part is transported back to the outdoor unit 10 by the fourth pipeline 94 through the fourth check valve 44, the second jet pump 42, the fourth solenoid valve 46, the second gas-liquid separator 41 and the liquid pipe 70 to complete the cycle.

Furthermore, during the heating process of the first indoor unit 30, the first solenoid valve 25 in the first relay unit 20 is in an open state, the second solenoid valve 26 is in a closed state, the first expansion valve 27 is in an open state, and the second solenoid valve is in an open state. The valve opening of the first expansion valve 27 is relatively small, and the second expansion valve 28 is in a closed state.

Still further, during the cooling process of the second indoor unit 50 , the third solenoid valve 45 is in the closed state, the fourth solenoid valve 46 is in the open state, and the third expansion valve 47 and the fourth expansion valve 48 are in the closed state.

Preferably, when the heating is the main mode, most of the high-pressure liquid refrigerant delivered in the second transfer unit is distributed to the second jet pump 42 as the driving flow of the refrigerant delivered to the second indoor unit 50 . In addition, the refrigerant sent to the second indoor unit 50 is returned to the outdoor unit 10 through the liquid pipe 70 after being boosted from evaporation by the second jet pump 42 . As the second expansion valve 27 in the first relay unit 20 that uses heating, in order to make the return liquid refrigerant flow to the second relay unit 40 on the cooling side, it can be adjusted to be fully closed, but the opening degree needs to be adjusted according to the cooling ratio (using The third pipeline 93 and the fourth pipeline 94 of refrigeration have excessive pressure loss, etc.).

Preferably, referring to Fig. 6, when the heating mode is the main mode, the second indoor unit 50 is cooling, and the high-pressure liquid refrigerant flowing from the second check valve 44 to the second injection pump 42 is injected at a high speed by the nozzle as the driving flow, forming an internal In the low-pressure space, the low-pressure gaseous refrigerant flowing from the first check valve 43 to the second jet pump 42 is sucked into the second jet pump 42 as a suction flow, mixed in the mixing part 421 of the second jet pump 42, and the mixed fluid While reducing the velocity in the diffuser, its kinetic energy is recovered almost without loss, further realizing the purpose of pressure recovery.

Among them, _PH is the initial pressure value when the high-pressure liquid refrigerant as the driving flow enters the second jet pump 42, _PL is the initial pressure value when the low-pressure gaseous refrigerant as the suction flow enters the second jet pump 42, _PS is the driving force P _D is the pressure value of the mixed fluid at the outlet of the second jet pump 42 .

Furthermore, it is transported to the gas chamber 411 and the liquid chamber 412 in the second gas-liquid separator 41. At this time, since the fourth expansion valve 48 is in a closed state, the separated gaseous refrigerant will not enter through the fourth expansion valve 48. In the gas pipe 60, the second gas-liquid separator 41 can be used as a storage at this time. When the low-pressure gaseous refrigerant and the high-pressure liquid refrigerant in the second jet pump 42 cannot be fully mixed, the mixed fluid can be stored in the second gas-liquid separator 41. Further achieve buffering, and finally deliver the final mixed fluid to the liquid pipe 70, and further deliver it to the outdoor 10 to realize circulation. It can be understood that the mixed fluid is mainly high-pressure liquid mixed with a small amount of gas; The mixed fluid in the second gas-liquid separator 41 can also be separated from the mixed fluid in the gas-liquid separator 41 by adding piping, and then sent to the second compressor 422 and the condenser 423 by the newly installed piping to realize The purpose of heating or cooling is achieved through the evaporator. The cooling or heating process in this process is consistent with the method in the prior art, and will not be repeated here.

Although the present invention is disclosed above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (10)

1. A multi-split air conditioner, comprising:

an outdoor unit (10);

a plurality of relay units connected to the outdoor unit through air pipes (60) and liquid pipes (70);

the indoor units are connected with the transfer units in a one-to-one corresponding mode;

and a waste heat recovery pipe (80) disposed between the plurality of relay units, for recovering waste heat between the relay units.

2. A multi-split air conditioner as recited in claim 1,

each transfer unit comprises a gas-liquid separator, and when the outdoor unit (10) is in a refrigeration main mode, a high-pressure refrigerant is separated into a high-pressure gaseous refrigerant and a high-pressure liquid refrigerant through the gas-liquid separator, if any indoor unit is in a heating mode, the high-pressure gaseous refrigerant is conveyed, and if any indoor unit is in a refrigeration mode, the high-pressure liquid refrigerant is conveyed.

3. A multi-split air conditioner as recited in claim 2,

and the liquid refrigerant of the indoor unit in the heating mode is conveyed to the indoor unit in the cooling mode through the waste heat recovery pipe (80).

4. A multi-split air conditioner as recited in claim 3,

the gas-liquid separator is arranged between the liquid pipe (70) and the indoor unit, the gas-liquid separator comprises an inlet, a gas outlet and an outlet, the outlet of the gas-liquid separator of the indoor unit in a refrigeration mode is communicated with a refrigerant inlet of the indoor unit, and the gas outlet is communicated with the gas pipe (60); the gas outlet of the gas-liquid separator of the indoor unit in the heating mode is communicated with the refrigerant inlet of the indoor unit, and the outlet is communicated with the refrigerant inlet of the indoor unit in the cooling mode through the waste heat recovery pipe (80); the inlet is in communication with the liquid tube (70).

5. A multi-split air conditioner as recited in claim 4,

the refrigerant outlet of the indoor unit in the heating mode is communicated with the refrigerant inlet of the indoor unit in the cooling mode through the waste heat recovery pipe (80).

6. A multi-split air conditioner as recited in claim 1,

each transfer unit comprises an injection pump, and when the outdoor unit (10) is in a heating main mode, if any indoor unit is in the heating mode, high-pressure gaseous refrigerant is conveyed to the outdoor unit, and part of the high-pressure liquid refrigerant passing through the indoor unit is conveyed to the liquid pipe; the other part is delivered to a relay unit of the indoor unit in the cooling mode through the waste heat recovery pipe (80).

7. A multi-split air conditioner as claimed in claim 6, wherein a portion of the high pressure liquid refrigerant, which is delivered to the relay unit of the indoor unit in the cooling mode by the waste heat recovery pipe (80), is delivered to the indoor unit in the cooling mode; the other part is conveyed to the jet pump;

the high-pressure liquid refrigerant conveyed to the jet pump is used for guiding low-pressure gaseous refrigerant generated by the indoor unit in the refrigeration mode.

8. A multi-split air conditioner as recited in claim 7,

each transfer unit further comprises a gas-liquid separator, the gas-liquid separator is arranged between the liquid pipe (70) and each indoor unit, and the gas-liquid separator comprises an inlet, a gas outlet and an outlet.

9. A multi-split air conditioner as recited in claim 8,

the refrigerant outlet of the indoor unit in the heating mode is communicated with the inlet of the gas-liquid separator when the outdoor unit (10) is in the heating main mode; a refrigerant outlet of the indoor unit in the refrigeration mode is communicated with the inlet through the jet pump; the outlet of the gas-liquid separator is communicated with the liquid pipe.

10. A multi-split air conditioner as claimed in any one of claims 8 to 9, wherein the injection pump is provided with: a drive inlet, a suction inlet, and a jet pump outlet;

the refrigerant outlet of the indoor unit in the cooling mode is communicated with the suction inlet when the outdoor unit (10) is in the main heating mode; the drive flow inlet is communicated with the waste heat recovery pipe (80); and the outlet of the jet pump is communicated with the inlet of the gas-liquid separator.

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