ES2307629T3 - AIR CONDITIONER. - Google Patents

Abstract

An air conditioner comprising a refrigerant circuit formed of an outdoor unit refrigerant circuit including at least a compressor (101), a four-way valve (102) and an outdoor heat exchanger (103) arranged in an outdoor unit (100), and an indoor heat exchanger (201) arranged in an indoor unit (200) and connected to said outdoor unit refrigerant circuit by a liquid-side pipe and a gas-side pipe, wherein a bypass circuit forming a bypass between said liquid-side and gas-side pipes (131,132) is provided with a receiver (121) for collecting liquid refrigerant, and refrigerant on-off means (128,129) arranged in a liquid pipe connection pipe (122) connecting said receiver (121) to said liquid-side pipe (131) and in a gas pipe connecting pipe (123) connecting said receiver (121) to said gas-side pipe (132), said refrigerant on-off means (128,129) is controlled based on determination of presence/absence of surplus refrigerant performed by determining a current heat exchanging performance of said outdoor heat exchanger (103), and thereby an amount of the refrigerant in said receiver (121) is controlled.

Description

Air conditioner.

The present invention relates to a air conditioner, and particularly to a conditioner of air provided with a receiver to collect refrigerant surplus.

Background Technique

A refrigerant circuit of a conditioner air is formed of a refrigerant pipe structure that connects an accumulator, a compressor, a four-way valve and an outdoor heat exchanger, which are arranged in an outdoor unit, as well as a heat exchanger of interior arranged in an indoor unit, and provides a refrigerant circulation path.

When the refrigerant circuit of the air conditioner works to cool, the four valve tracks controls a direction of refrigerant circulation so that the outdoor heat exchanger works like condenser, and the indoor heat exchanger works as evaporator. In a heating operation, the four valve tracks controls the direction of refrigerant circulation so that the outdoor heat exchanger works as an evaporator, and the indoor heat exchanger works like condenser.

In the previous air conditioner, in view of ease of installation, it is desired that the circuit of refrigerant on the side of the outdoor unit is filled with a appropriate amount of refrigerant containing an amount additional refrigerant, which is required for a pipeline connection of a maximum length. However, the appropriate amount of refrigerant, which is required during an operation, changes significantly depending on one mode of operation, a indoor unit capacity and a pipe length of connection used for the actual installation. Therefore, in the refrigerant circuit refrigerant may be present leftover, and this can cause abnormal pressure rise when it stays in the condenser, and can reduce the efficiency of operation.

To handle such leftover refrigerant, it has proposed to arrange a receiver between the heat exchanger outdoor and a liquid shut-off valve to collect the leftover refrigerant

In a conventional receiver circuit, a receiver is arranged in a part of pipe on one side of the liquid pipe between the outdoor heat exchanger and the liquid shut-off valve, and is located in series with it. Therefore, the amount of refrigerant in the receiver increases or decreases simply according to an opening degree of a motor operated valve located downstream of the receiver. This motor operated valve corresponds to each valve operated by room engine in a cooling operation, and corresponds to a main pressure reducing valve, and the degree of opening It is controlled based on a degree of overheating. Therefore, it is difficult to precisely control or adjust the amount of coolant in the receiver, and particularly, it is impossible to control the amount of liquid refrigerant in the receiver when a special operation is performed, such as a operation with a low outside air temperature or with a load excessive

For example, when an operation of cooling when the outside air temperature is extremely low, the outdoor heat exchanger has an excessively large capacity, so that the pressure in the High pressure side is reduced. Therefore, a difference between high and low pressures, which reduces the compressor reliability. If the remaining refrigerant, which is collected in the receiver, it can be transferred to the heat exchanger of outside, a part of the outdoor heat exchanger can fill with excess coolant. Thus, the capacity of the outdoor heat exchanger is reduced, and the pressure in the high pressure side rises so that you can ensure a sufficient pressure difference.

The two documents JP 60 114669A and JP 2000 146322A unveil an air conditioner according to the preamble of the claim 1.

Exhibition of the invention

The object of the invention is to control the leftover refrigerant according to operating situations as a cooling operation at an air temperature lower exterior and an operation with excessive load.

An air conditioner according to the invention includes the features of claim 1.

The dependent claims are listed preferred optional features.

Brief description of the drawings

Fig. 1 schematically shows a circuit of refrigerant from an air conditioner that uses a embodiment of the invention;

Figs. 2 to 5 are control flowcharts of the embodiment of the invention, respectively;

Figs. 6 to 9 are control flowcharts of a second embodiment, respectively;

Figs. 10 to 13 are control flowcharts of a third embodiment, respectively;

Figs. 14 to 17 are control flowcharts of a fourth embodiment, respectively;

Fig. 18 is a block diagram of control of one embodiment;

Fig. 19 is a block diagram of control of a compressor activation circuit;

Fig. 20 is an organization chart showing a way of estimating a saturation temperature corresponding to high pressure; Y

Fig. 21 shows a table to calculate a saturation temperature

Description of preferred embodiments

First realization

Schematic structure

An air conditioner that uses a first embodiment, which is according to the invention, has a circuit of refrigerant shown in Fig. 1.

An outdoor unit 100 includes a circuit of outdoor refrigerant provided with a compressor 101, a four-way valve 102, an outdoor heat exchanger 103 and an accumulator 105. A pressure protection switch of the discharge side 108 is disposed on the discharge side of the compressor 101 to detect the abnormal rise in pressure of discharge. An intake side pressure sensor 110 is arranged on the intake side of the compressor 101 to detect a intake pressure

An oil separator 107 is arranged in the discharge side of compressor 101 to separate and return to accumulator 105 the lubricating oil contained in the refrigerant. He oil separator 107 is provided with a pipe thermistor of discharge 109 to detect a temperature on the discharge side of the compressor 101.

An oil return pipe 197 of the oil separator 107 is provided with a branch circuit discharge 194, which forks from the return pipe of oil 197, and is connected to an inlet side of the accumulator 105. This discharge branch circuit 194 is provided with a portion of heat exchanger pipe 196 arranged inside the accumulator 105 and a motor driven valve of discharge-admission 142 for capacity control. The oil return line 197 of oil separator 107 is provided with a capillary 141, which is also connected to the side of accumulator intake 105.

The outdoor unit 100 is also provided of an outdoor air thermistor 111 to detect a temperature outside air, an outdoor heat exchange thermistor 112 to detect an outlet temperature of the exchanger of outdoor heat 103, and an intermediate exchange thermistor of heat 113 to detect an intermediate temperature of heat exchanger. The outdoor unit 100 is provided in addition to a fan 106 for heat exchange between the outside air introduced in unit 100 and the refrigerant circulating inside the heat exchanger of exterior 103, and a fan motor 104 to activate the fan 106.

The refrigerant pipe that extends from the outdoor unit 100 towards the indoor unit is provided of a liquid pipe connection hole 114 connected to the outdoor heat exchanger 103, and a connection hole of gas pipe 115 connected to the heat exchanger of outside 103 by four-way valve 102. Holes 114 and 115 are internally provided with a shut-off valve liquid pipe 116 and a gas pipe shutoff valve 117, respectively.

The outdoor unit 100 includes a receiver 121 to temporarily store excess coolant, which circulates from the outdoor heat exchanger 103 serving as a condenser in the cooling operation. Receiver 121 it is provided with a liquid pipe connection pipe 122 and a gas pipe connection pipe 123. The pipeline liquid pipe connection 122 is connected to a part of liquid side pipe 131 between the heat exchanger of outside 103 and the liquid pipe shutoff valve 116. The Gas pipe connection pipe 123 is connected to a part of gas side pipe 132 between four-way valve 102 and the gas pipe shutoff valve 117.

The liquid pipe connection pipe 122 of receiver 121 is provided with a motor operated valve of the liquid pipe (EVL) 128 which has a function of pressure reduction and a coolant shutdown function. The Gas pipe connection pipe 123 is provided with a Gas pipeline motor driven valve (EVG) 129.

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An auxiliary heat exchanger 133 is disposed between the gas-driven valve of the gas pipe 129 and a connection to the pipe side of the gas side 132. A subcooling heat exchanger 134 is arranged in an outlet of the liquid side of the heat exchanger of exterior 103.

A gas vent capillary 130 is directed towards a part of the gas side pipe part 132 between the four-way valve 102 and the shut-off valve gas pipe 117 to collect a refrigerant gas from the receiver 121.

A plurality of branches 300A, 300B, ... are connected to each of the pipe connection holes of liquid 114 and the gas pipe connection holes 115 of the outdoor unit 100. Like these branches 300A, 300B, ... they have the same structures, the description will only be given below on the 300A branch, and the others will not be described.

The 300A branch includes a connection hole liquid pipe on the outer side 301 connected to the hole of liquid pipe connection 114 of outdoor unit 100 and a gas pipe connection hole on the inner side 303 connected to the gas pipe connection hole 115 of the unit outside 100. The 300A branch has liquid side branches divided into the connection hole of the outer side 301, and the ends of these branches form a plurality of holes of liquid pipe connection of the inner side 302 in equal number that the indoor units connected to them. The branch 300A also has gas side branches divided into the gas pipe connection hole on the outer side 303, and the ends of these branches form pipe connection holes of gas from the inner side 304 in the same number as the units of Interior connected to them. In the following description, it is assumed that the indoor units connected to the holes are three, and the liquid pipe connection holes on the side are used 302A, 302B and 302C as well as the connection holes of gas pipe on the inner side 304A, 304B and 304C. One valve motor driven 308 for bypass is arranged between the liquid pipe connection hole on the outer side 301 and the gas pipe connection hole on the outside side 303

The branches, which extend from the hole of liquid pipe connection of the outer side 301 inside the 300A branch to the liquid pipe connection holes of the indoor side 302A - 302C, respectively, are provided with 305A - 305C motor operated valves to reduce pressures of the refrigerant that circulates through them, as well as 306A - 306C liquid pipe thermistors to detect coolant temperatures circulating through them, respectively. The branches, which extend from the hole of gas pipe connection on the outer side 303 inside the branch 300A to the gas pipe connection holes on the side of interior 304A - 304C, respectively, are provided with 307A - 307C gas pipe thermistors to detect coolant temperatures circulating through them, respectively.

Each of the branches 330A, 300B, ... is connected to a plurality of outdoor units 200. In the structure shown in Fig. 1, it is assumed that they may be connected three outdoor units to each of the branches 300A, 300B, ... so that the outdoor units 200A - 200C are connected to the 300A branch, and the 200D outdoor units - 200F are connected to the 300B branch. Each of the units of indoor 200A - 200F can be used in the indoor unit of a type of multiple units or a type of pair of units. In the following description, the indoor unit 200A is of the type of pair of units.

The indoor unit 200A is provided with a indoor heat exchanger 201, which is connected to a refrigerant pipe that extends to the outdoor unit through a liquid pipe connection hole 204 and a gas pipe connection hole 205. The indoor unit 200A is provided with a room temperature thermistor 202 for detect an ambient temperature and an exchange thermistor of indoor heat 203 to detect a temperature of indoor heat exchanger 201.

If the indoor units connected to the 300A and 300B branches are of the multiple unit type, the part of liquid side pipe may be provided with a thermistor of liquid pipe to detect coolant temperature circulating through it, in which case the thermistors of liquid pipe of branches 300A and 300B can be removed

Control of excess refrigerant in the operation of cooling

In the cooling operation, the refrigerant leftover is controlled according to a pipe temperature of liquid This will be described later with reference to a Organization chart of Fig. 2.

In a step S11, it is determined whether a coolant control sampling time has elapsed or not surplus TSCSET. When it is determined that an elapsed time counted by a timer has reached the sampling time of TSCSET excess refrigerant control, the process goes to a stage S12

In step S12, the temperature is calculated target of the liquid pipe.

The process of calculation of the target temperature of the liquid pipe with reference to an organization chart of Fig. 3.

In step S21, a DOATD variable is calculated according to the following formula using calculation coefficients of target temperature of the liquid pipe KSCC1, KSCC2, KSCC3 and EDOSC, an FMK target frequency of compressor 101, a temperature deviation of the discharge pipe EDO and others.

DOATD = KSCC1 x FMK + KSCC2 - (EDO - EDOSC) x KSCC3

In a step S22, it is determined whether the variable DOATD is greater than a lower DOATDMIN temperature limit target the liquid pipe or not. When it is determined that the DOATD variable is not greater than the lower limit DOATDMIN of the target temperature of the liquid pipe, the process goes to a step S23. In step S23, the value of the DOATD variable is set as the lower limit DOATDMIN of the temperature target of the liquid pipe.

In a step S24, it is determined whether the variable DOATD is equal to or less than ((upper limit DOATDMAX of the target temperature of the liquid pipe) - (temperature of outside air DOA)) or not. When it is determined that the DOATD variable is greater than ((upper limit DOATDMAX of the target temperature of the liquid pipe) - (DOA outdoor air temperature)), The process goes to an S25 stage. In step S25, the value of the DOATD variable is set to ((upper limit DOATDMAX of the target temperature of the liquid pipe) - (temperature of outdoor air DOA)).

In a step S26, a temperature is calculated target of the DELSET liquid pipe. In this embodiment, it Use the following formula for this calculation.

DELSET = DOA (outside air temperature) + DOATD (variable)

In a step S13, a deviation of liquid pipe temperature ΔDEL from the target temperature of the DELSET liquid pipe and the outlet temperature of the outdoor heat exchanger DEL According to the following formula.

ΔDEL = DELSET - OF THE

In a step S14, the process is performed to calculate an amount or degree, which the valve has to be operated motor driven.

This process of calculating the amount of motor driven valve actuation is shown in a Organization chart of Fig. 4.

In a step S31, an amount of POSC motor driven valve drive according to The following formula using KOSCA1 and KOSCA coefficients, which are coefficients to calculate the amount of actuation of the motor operated valve, the temperature deviation of the liquid pipe ΔDEL, the last temperature deviation of the liquid pipeline? DeltaDELZ and others.

POSC = KOSCA1 x ((\ DeltaDEL - \ DeltaDELZ) + ΔDEL / KOSCA)

In a step S15, the valve is operated motor driven according to drive quantity determined in step S14.

The process of operating the valve actuated by Engine is shown in a flow chart of Fig. 5.

It is assumed that an EVL degree of opening of the motor driven valve of liquid pipe 128 is defined by ((current EVL grade) + (amount of actuation of the POSC motor driven valve)). At the same time, a EVG degree of motor-operated valve opening of the 129 gas pipe to reach ((current EVG grade) + (amount of POSC drive) x KPOSC1).

The temperature of the liquid pipe during the cooling operation can be determined from a value detected by the outdoor heat exchange thermistor 112 arranged near the exit of the exchanger of external heat 103. Based on the pipe temperature of liquid, it is possible to control the amount of the refrigerant leftover at receiver 121.

Therefore, even when the operation of cooling is performed while an outside air temperature is low, the amount of the remaining refrigerant is controlled to ensure a difference between high and low pressures in the compressor 101.

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Second realization

Control of excess refrigerant in the operation of cooling

Referring to a flow chart of Fig. 6, the description on control of surplus refrigerant made with a saturation temperature corresponding to high pressure in the cooling operation. Be assumes that the same refrigerant circuit is used as in the first embodiment to control the remaining refrigerant in the cooling operation The second embodiment is not part of the invention.

In a step S51, it is determined whether a coolant control sampling time has elapsed or not surplus TSCSET. When it is determined that an elapsed time counted by the timer has reached the sampling time of TSCSET excess refrigerant control, the process goes to a stage S52.

In step S52, the temperature of target saturation corresponding to high pressure.

The process of calculation of the target saturation temperature corresponding to high pressure with reference to an organization chart of Fig. 7.

In step S61, the DOATD variable of according to the following formula using calculation coefficients of target saturation temperature corresponding to high pressure KSCC1, KSCC2, KSCC3 and EDOSC, the FMK target frequency of the compressor 101, the temperature deviation of the pipeline download EDO and others.

DOATD = KSCC1 x FMK + KSCC2 - (EDO - EDOSC) x KSCC3

In a step S62, it is determined whether the variable DOATD is greater than a lower DOATDMIN limit of the temperature of target saturation corresponding to high pressure or not. When determines that the DOATD variable is not greater than the lower limit DOATDMIN of the target saturation temperature corresponding to high pressure, the process goes to an S63 stage. In step S63, the DOATD variable value is set as the lower limit DOATDMIN of the target saturation temperature corresponding to high pressure.

In an S64 step, it is determined whether the variable DOATD is equal to or less than the upper limit DOATDMAX of the target saturation temperature corresponding to high pressure or no. When it is determined that the DOATD variable is greater than the DOATDMAX upper limit of the target saturation temperature corresponding to high pressure, the process goes to a step S65. In step S65, the value of the DOATD variable is set as the DOATDMAX upper limit of the target saturation temperature corresponding to high pressure.

In a step S66, the temperature of target saturation corresponding to high pressure TDSSET. In this embodiment, the following formula is used for this calculation.

TDSSET = DOA (outside air temperature) + DOATD (variable)

In a step S53, a deviation of saturation temperature corresponding to high pressure ΔTDS  from the saturation temperature corresponding to high TDSSET pressure and target saturation temperature corresponding to high pressure TDSSET TDS according to the following formula

ΔTDS = TDSSET - TDS

In a step S54, the process is performed to calculate an amount or degree, which the valve has to be operated motor driven.

This process of calculating the amount of motor driven valve actuation is shown in a Organization chart of Fig. 8.

In a step S71, the amount of POSC motor driven valve drive according to The following formula using the KOSCA1 and KOSCA coefficients, which are coefficients to calculate the amount of actuation of the motor operated valve, temperature deviation of saturation corresponding to high pressure ΔTDS, the last saturation temperature deviation corresponding to high pressure ΔTDSZ and others.

POSC = KOSCA1 x ((\ DeltaTDS - \ DeltaTDSZ) + ΔTDS / KOSCA)

In a step S55, the valve is operated motor driven according to drive quantity determined in step S54.

The process of operating the valve actuated by Engine is shown in a flow chart of Fig. 9.

The opening EVL degree of the motor driven valve of liquid pipe 128 is defined by ((current EVL grade) + (amount of actuation of the POSC motor driven valve)). At the same time, the EVG degree of motor-operated valve opening of the 129 gas pipe to reach ((current EVG grade) + (amount of POSC drive) x KPOSC1).

Third realization

Referring to a flow chart of Fig. 10, the description on control of leftover refrigerant made with a pipeline temperature of liquid in the heating operation. The third embodiment does not It is part of the invention.

In a step S91, it is determined whether a coolant control sampling time has elapsed or not surplus TSCSET. When it is determined that an elapsed time counted by a timer has reached the sampling time of TSCSET excess refrigerant control, the process goes to a stage S92

In step S92, the temperature is calculated target of the liquid pipe.

The process of calculation of the target temperature of the liquid pipe with reference to an organization chart of Fig. 11.

In step S101, the DOATD variable is calculated according to the following formula using calculation coefficients of target temperature of the liquid pipe KSCC1 and KSCC2, the FMK target frequency of compressor 101 and others.

DOATD = KSCC1 x FMK + KSCC2

In a step S102, it is determined whether the variable DOATD is greater than the lower DOATDMIN temperature limit target the liquid pipe or not. When it is determined that the DOATD variable is not greater than the lower limit DOATDMIN of the target temperature of the liquid pipe, the process goes to a step S103. In step S103, the value of the DOATD variable is set as the lower limit DOATDMIN of the temperature target of the liquid pipe.

In a step S104, it is determined whether the variable DOATD is equal to or less than ((upper limit DOATDMAX of the target temperature of the liquid pipe) - temperature DA environment) or not. When it is determined that the DOATD variable is greater than ((upper limit DOATDMAX of the target temperature of the liquid pipe) - room temperature DA), the process passes to a step S105. In step S105, the value of the DOATD variable is set to ((upper limit DOATDMAX of temperature target of the liquid pipe) - room temperature DA)).

In a step S106, a temperature is calculated target of the DLSET liquid pipe. In this embodiment, it Use the following formula for this calculation.

DLSET = DA (room temperature) + DOATD (variable)

In a step S93, a deviation of liquid pipe temperature ΔDL. For him indoor heat exchanger 201 having the temperature of the lowest liquid pipe in the indoor unit 200, which is working, the temperature deviation of the pipeline from liquid ΔDL is calculated from a representative value DL of liquid pipe temperature and temperature target of the DLSET liquid pipe according to the following formula.

ΔDL = DLSET - DL

In an S94 step, the process is performed to calculate an amount or degree, which the valve has to be operated motor driven.

This process of calculating the amount of motor driven valve actuation is shown in a Organization chart of Fig. 12.

In a step S111, the amount of POSC motor driven valve drive according to The following formula using the KOSCA1 and KOSCA coefficients, which are coefficients to calculate the amount of actuation of the motor operated valve, the temperature deviation of the liquid pipe ΔDL, the last temperature deviation of the liquid pipe ΔDLZ and others.

POSC = KOSCA1 x ((\ DeltaDL - \ DeltaDLZ) + ΔDL / KOSCA)

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In a step S95, the valve is operated motor driven according to drive quantity determined in step S94.

The process of operating the valve actuated by Engine is shown in a flow chart of Fig. 13.

The opening EVG degree of the motor driven valve of gas pipe 129 is defined by ((current EVG grade) + (valve actuation amount driven by POSC engine)). Likewise, the EVL degree of motor driven valve opening of the liquid pipe 128 to reach ((current EVL grade) + (drive quantity POSC) x KPOSC1).

In the heating operation, the temperature of the lowest liquid pipe in the indoor unit 200, which it is working, it is used as the representative value of the temperature of the liquid pipe, and the amount of excess refrigerant in receiver 121 can be controlled with this representative value of the pipe temperature of liquid.

Quarter realization

Referring to a flow chart of Fig. 14, the description on control of surplus refrigerant made with a saturation temperature corresponding to high pressure in the heating operation. The Second embodiment is also not part of the invention.

In a step S131, it is determined whether a coolant control sampling time has elapsed or not surplus TSCSET. When it is determined that an elapsed time counted by the timer has reached the sampling time of TSCSET excess refrigerant control, the process goes to a stage S132.

In step S132, the temperature of target saturation corresponding to high pressure.

The process of calculation of the target saturation temperature corresponding to high pressure with reference to an organization chart of Fig. 15.

In step S141, the DOATD variable is calculated according to the following formula using the coefficients of target saturation temperature calculation corresponding to high KSCC1 and KSCC2 pressure, the FMK target frequency of the compressor 101, and others.

DOATD = KSCC1 x FMK + KSCC2

In a step S142, it is determined whether the variable DOATD is greater than a lower DOATDMIN limit of the temperature of target saturation corresponding to high pressure or not. When determines that the DOATD variable is not greater than the lower limit DOATDMIN of the target saturation temperature corresponding to high pressure, the process goes to an S143 stage. In step S143, the value of the DOATD variable is set as the lower limit DOATDMIN of the target saturation temperature corresponding to high pressure.

In a step S144, it is determined whether the variable DOATD is equal to or less than the upper limit DOATDMAX of the target saturation temperature corresponding to high pressure or no. When it is determined that the DOATD variable is greater than the DOATDMAX upper limit of the target saturation temperature corresponding to high pressure, the process goes to a step S145. In step S145, the value of the DOATD variable is set as the upper limit DOATDMAX of the target saturation temperature corresponding to high pressure.

In a step S146, the temperature of target saturation corresponding to high pressure TDSSET. In this embodiment, the following formula is used for this calculation.

TDSSET = DA (room temperature) + DOATD (variable)

In a step S133, the deviation of saturation temperature corresponding to high pressure ΔTDS. Saturation temperature deviation corresponding to high pressure ΔTDS is calculated from the saturation temperature corresponding to high pressure TDS and the target saturation temperature corresponding to high pressure TDSSET according to the following formula.

ΔTDS = TDSSET - TDS

In a step S134, the process is performed to calculate an amount or degree, which the valve has to be operated motor driven.

This process of calculating the amount of motor driven valve actuation is shown in a Organization chart of Fig. 16.

In a step S151, the amount of POSC motor driven valve drive according to The following formula using the KOSCA1 and KOSCA coefficients, which are coefficients to calculate the amount of actuation of the motor operated valve, temperature deviation of saturation corresponding to high pressure ΔTDS, the last saturation temperature deviation corresponding to high pressure ΔTDSZ and others.

POSC = KOSCA1 x ((\ DeltaTDS - \ DeltaTDSZ) + ΔTDS / KOSCA)

In a step S135, the valve is operated motor driven according to drive quantity determined in step S134.

The process of operating the valve actuated by Engine is shown in a flow chart of Fig. 17.

The opening EVG degree of the motor driven valve of gas pipe 129 is defined by ((current EVG grade) + (valve actuation amount driven by POSC engine)). Likewise, the EVL degree of motor driven valve opening of the liquid pipe 128 to reach ((current EVL grade) + (drive quantity POSC) x KPOSC1).

Estimation of the saturation temperature corresponding to high pressure

The description of a way to estimate the saturation temperature corresponding to high pressure in the second embodiment already described. In Fig. 18, shows a control block for this estimate.

A control part 501 is formed of a microprocessor that includes a CPU, a ROM, a RAM and others, and is connected to a ROM 502 that stores a control program of operation and various parameters as well as a RAM 503 to store Temporarily work variables.

The control part 501 is also connected to various sensor elements that include the pressure sensor of the intake side 110, discharge pipe thermistor 109, the outdoor air thermistor 111, the exchange thermistor of outside heat 112 and the intermediate exchange thermistor heat 113, which are arranged inside an outdoor unit 100, to receive values detected by these sensors and thermistors In addition, the discharge side pressure switch 108 is connected to the control part 501.

A communication interface on the side of 504 interior to transmit various data between the unit interior 200 and the branch 300 is connected to the control part 501

In addition, the control part 501 is connected to a 505 compressor activation circuit to control the operating frequency of compressor 101 and a circuit of 506 fan motor activation to control a fan motor frequency 104.

The control part 501 is further connected to the motor-driven valves of liquid and gas pipes 128 and 129 arranged on opposite sides of receiver 121, and the valve operated by discharge-intake motor 142 arranged in the discharge bypass circuit 194 of the compressor 101.

The 505 compressor activation circuit is provided with an active filter circuit, which will be described afterwards, and a 507 secondary voltage sensor and a sensor secondary current 508 of the active filter circuit are connected to the control part 501.

Fig. 19 is a block diagram showing the control of the activation circuit of the compressor 505 of Fig. 18.

The 505 compressor activation circuit includes a rectifier circuit 512 connected to a source of commercial supply 511, an active filter circuit 513 and a inverter circuit 514.

The rectifier circuit 512 is formed of a diode bridge that includes four diodes, and performs rectification full wave over an AC power supplied from the commercial power supply 511.

The active filter circuit 513 includes a reactor 521, a diode 522, a capacitor 523, an element switch 524 and active filter activation means 525 for perform switching control of switching element 524.

The active filter 513 includes a sensor primary voltage 526 to detect a primary voltage, a sensor of primary current 527 to detect a primary current, a 507 secondary voltage sensor to detect a voltage secondary and a secondary current sensor 508 to detect a secondary current The activation means of the active filter 525 performs the switching control on the switching element 524 so that the secondary voltage detected by the sensor secondary voltage 507 can be made equal to a voltage predetermined. At the same time, the filter activation medium active 525 controls the current value detected by the sensor of primary current 527 so that it coincides in phase with the primary voltage detected by primary voltage sensor 526. This significantly increases a power factor, and from that mode increases the accuracy of power consumption calculation based on the secondary voltage detected by the voltage sensor secondary 507 and the secondary current detected by the sensor secondary current 508.

The inverter circuit 514 produces a signal of pulses of a constant voltage from an output signal of a predetermined voltage sent from the active filter circuit 513. The output frequency of the inverter circuit 514 in this operation is equal to the operating frequency of the compressor determined based on current operating situations. By therefore, the activation motor of the compressor 513 is activated from according to the output frequency of the inverter circuit 514.

The power consumption of the compressor 101 is calculated from the value of the secondary voltage and the value of the secondary current of the active filter 513 of the circuit 505 compressor activation, and a value of the temperature corresponding to high pressure based on consumption of energy thus calculated. A way will be described below. for this estimate with reference to an organization chart of Fig. twenty.

In a step S171, a voltage of VIN input and an IIN input current applied to the circuit inverter 514. The input voltage VIN and the input current IINs applied to inverter circuit 514 can be obtained from the sensor secondary voltage 507 and secondary current sensor 508, that detect the secondary voltage and current of the active filter 513, respectively.

In a step S172, the consumption of INPUT power of compressor 101 based on secondary voltage VIN and the secondary current IIN of the active filter 513. As the switching element 524 is controlled so that the means of activation of active filter 525 of active filter 513 may have an appropriate power factor, the factor can be considered of power is equal to one. Therefore, the energy consumption of Compressor can be determined by the following formula.

INPUT = VIN x IIN x 1 (factor of power)

In a step S173, the process is performed to determine a FOUT output frequency to activate the compressor 101 as well as an intake pressure value LP thereof. In this process, FOUT output frequency can be determined specifically from the output frequency of the inverter 514 which activates the activation motor of the compressor 531. The value of LP intake pressure can be determined specifically from of the detected value of the intake pressure sensor 110.

In a step S174, a high value is determined pressure based on INPUT power consumption, the frequency of FOUT output and the intake pressure value LP. This determination It is done according to the following formula, which uses constants High pressure estimation KHPLL, KHPFF, KHPII, KHPLF, KHPFI, KHPLI, KHPL, KHPF, KHPI and KHPC as well as a correction value of HPHOSEI high pressure.

HP = KHPLL x LP 2 + KHPFF x FOUT 2 + KHPII x INPUT 2 + KHPLF x LP x FOUT + KHPFI x FOUT x INPUT + KHPLI x LP x INPUT + KHPL x LP + KHPF x FOUT + KHPI x INPUT + KHPC + HPHOSEI.

In a step S157, the transmission of saturation corresponding to high pressure TDS based on the value HP high pressure calculated in step S174. For this you can Use the following formula.

TDS = A x HP + B

where the coefficients A and B for calculate the saturation temperature corresponding to high pressure are determined by the high pressure value HP according to a table shown in Fig. twenty-one.

Industrial applicability

According to the invention, the amount of excess refrigerant collected inside the receiver of according to the operating situations, and the degree of supercooling or overheating within the outdoor heat exchanger. Therefore, a appropriate amount of refrigerant in the circuit system refrigerant for efficient activation.

Claims (8)

1. An air conditioner comprising a refrigerant circuit formed from a refrigerant circuit of an outdoor unit that includes at least one compressor (101), a four-way valve (102) and a heat exchanger exterior (103) arranged in an outdoor unit (100), and a indoor heat exchanger (201) arranged in one unit indoor (200) and connected to said refrigerant circuit of the outdoor unit by a liquid side pipe and a gas side pipe, in which a branch circuit that forms a branch between said pipes of the liquid side and the side of Gas (131, 132) is provided with a receiver (121) to collect liquid refrigerant, and means of coolant connection-disconnection (128, 129) arranged in a liquid pipe connection pipe (122) connecting said receiver (121) to said pipe on the side of liquid (131) and in a gas pipe connection pipe (123) connecting said receiver (121) to said gas side pipe (132), said means of coolant connection-disconnection (128, 129) is control based on the presence / absence determination of excess refrigerant made by determining a yield of current heat exchange of said heat exchanger of exterior (103), and in that way a quantity of refrigerant in said receiver (121), and the presence / absence of excess refrigerant is determined by making a comparison between a temperature of output of said outdoor heat exchanger (103) and a value target of the outlet temperature of said exchanger of outdoor heat (103), characterized because the target value of the outlet temperature of said outdoor heat exchanger (103) is determined to from a quantity of circulating refrigerant and a temperature of outside air in a cooling operation. 2. The air conditioner according to the claim 1, wherein said means of coolant connection-disconnection is formed from: a motor driven valve of the pipeline liquid (128) disposed in said liquid side pipe (122) and that it is capable of controlling a coolant flow rate, and a motor driven valve of the pipeline gas (129) disposed in said gas pipe connection pipe (123) and that is capable of controlling a coolant flow rate. 3. The air conditioner according to the claim 1, wherein a detected value of a pipe thermistor of exterior liquid (112) disposed in the immediate vicinity of the output of said outdoor heat exchanger (103) is used as the outlet temperature of said heat exchanger of exterior (103). 4. The air conditioner according to the claim 1, wherein the target value of the outlet temperature of said outdoor heat exchanger (103) is determined to from an operating frequency of said compressor (101) and the outside air temperature in a cooling operation. 5. The air conditioner according to the claim 1, wherein the target value of the outlet temperature of said outdoor heat exchanger (103) is corrected based on a deviation in an overheating control or a target temperature control of the piping.
discharge. 6. The air conditioner according to the claim 5, wherein the target value of the outlet temperature of said outdoor heat exchanger (103) is the same as or lower than the highest temperature between, a temperature of high pressure saturation and an intermediate temperature of heat exchange of said outdoor heat exchanger (103). 7. The air conditioner according to the claim 5 or 6, wherein the target value of the outlet temperature of said outdoor heat exchanger (103) is the same as or greater than a sum of a current outside air temperature and a predetermined temperature

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8. The air conditioner according to the claim 5, 6 or 7, wherein said motor driven valve of the pipeline of liquid (128) works in the cooling operation to open when the outlet temperature of said exchanger of outside heat (103) is lower than the target temperature, and to close when the outlet temperature of said outdoor heat exchanger (103) is greater than the target temperature