WO2007125959A1 - Air conditioner - Google Patents

Abstract

A separated-type air conditioner (1) where the labor of inputting information on refrigerant connection piping before starting operation of the air conditioner is reduced and where whether the amount of refrigerant in a refrigerant circuit is appropriate or not can be highly accurately determined. The air conditioner (1) has the refrigerant circuit (10) formed by connecting an outdoor unit (2) and an indoor unit (4) via the refrigerant connection piping (6, 7), operation control means capable of piping length determination operation, and piping length calculation means. The piping length determination operation is operation where the condition of control of constituting apparatuses is changed from a first condition to a second condition different from the first condition. The piping length calculation means calculates the length of the refrigerant connection piping (6, 7) based on a time period in which a change in the amount of operating conditions propagates in a predetermined segment of the refrigerant circuit (10) including at least the refrigerant connection piping (7), where the change appears in the refrigerant flowing in the refrigerant circuit (10) by the piping length determination operation.

Description

 Specification

 Air conditioner

 Technical field

 The present invention relates to a function for determining the suitability of the amount of refrigerant in a refrigerant circuit of an air conditioner, in particular, an air conditioner configured by connecting a heat source unit and a utilization unit via a refrigerant communication pipe. The present invention relates to a function for determining the suitability of the refrigerant amount in the refrigerant circuit.

 Background art

 Conventionally, a separate air conditioner configured by connecting a heat source unit and a utilization unit via a refrigerant communication pipe leads to an insufficient amount of refrigerant in the refrigerant circuit. In order to make it possible to accurately determine the length of the refrigerant communication pipe, information such as the length of the refrigerant communication pipe is input (for example, see Patent Document 1).

 Patent Document 1: JP-A-8-200905

 Disclosure of the invention

 [0003] However, the above-described operation of inputting information on the refrigerant communication pipe is a very time-consuming operation, and there is a problem that an input error is likely to occur.

 An object of the present invention is to make it possible to determine with high accuracy whether or not the amount of refrigerant in the refrigerant circuit is accurate, while reducing the effort of inputting information on the refrigerant communication pipe before the operation of the separate type air conditioner.

 [0004] The air conditioner according to the first invention is capable of performing a pipe length determination operation and a refrigerant circuit configured by connecting a heat source unit and a utilization unit via a refrigerant communication pipe. Operation control means and pipe length calculation means are provided. The pipe length judgment operation is an operation that changes the control state of the component equipment to the second state that is different from the first state force and the first state. The pipe length calculation means is a propagation time required for a change in the operation state quantity that appears in the refrigerant flowing in the refrigerant circuit by the pipe length judgment operation to propagate at least within a predetermined section in the refrigerant circuit including the refrigerant communication pipe. Based on the above, the pipe length of the refrigerant communication pipe is calculated.

In this air conditioner, the control state of the component devices is different from the first state to the first state. The pipe length judgment operation to be changed to the second state is performed, and the change in the operation state quantity that appears in the refrigerant flowing in the refrigerant circuit due to such a state change is at least within a predetermined section in the refrigerant circuit including the refrigerant communication pipe. For example, after installing the component equipment, the pipe length of the refrigerant communication pipe is calculated based on this propagation time. Even if is unknown, the pipe length of the refrigerant connection pipe can be known. Thus, the length of the refrigerant communication pipe can be obtained while reducing the time for inputting the information of the refrigerant communication pipe, and as a result, the suitability of the refrigerant amount in the refrigerant circuit can be determined with high accuracy.

 [0005] An air conditioner according to a second invention is the air conditioner according to the first invention, wherein the refrigerant circuit includes a compressor, a condenser, an expansion valve, and an evaporator. The operation control means changes the opening of the expansion valve to the first opening force as the first state and the second opening as the second state in the pipe length determination operation.

 In this air conditioner, in the pipe length determination operation, the opening of the expansion valve is changed to the first opening force as the first state and the second opening as the second state. The change of the operating state quantity appearing in the refrigerant flowing inside can be made to appear rapidly and clearly, and the propagation time can be accurately detected.

 [0006] An air conditioner according to the third invention is an air conditioner according to the second invention! The refrigerant communication pipe includes a liquid refrigerant communication pipe and a gas refrigerant communication pipe. . The heat source unit includes a compressor and a heat source side heat exchanger that can function as a condenser. The utilization unit has an expansion valve and a utilization-side heat exchange that can function as an evaporator. The refrigerant circuit is configured by connecting a compressor, a heat source side heat exchanger, a liquid refrigerant communication pipe, an expansion valve, a use side heat exchanger, and a gas refrigerant communication pipe. The propagation time is detected from the change in the operating state quantity of the refrigerant flowing on the suction side of the compressor in the pipe length judgment operation.

In this air conditioner, the operation state of the refrigerant flowing on the suction side of the compressor in the pipe length determination operation is used as the operation state quantity for detecting the propagation time in the pipe length determination operation in which the opening degree of the expansion valve is changed. Therefore, this change in the operating state quantity is required to propagate at least in a predetermined section in the refrigerant circuit including the gas refrigerant communication pipe. The sowing time can be detected, and the pipe length of the gas refrigerant communication pipe can be obtained from this propagation time.

 [0007] The air conditioner according to the fourth invention is the same as the air conditioner according to the third invention! The operating state quantity of the refrigerant flowing on the suction side of the compressor used for detecting the propagation time Is the degree of superheat of the refrigerant flowing on the suction side of the compressor.

 In this air conditioner, the degree of superheat of the refrigerant flowing on the suction side of the compressor is used as the operating state quantity of the refrigerant flowing on the suction side of the compressor used for detecting the propagation time. The effect of change becomes apparent and the propagation time can be detected more accurately.

 [0008] An air conditioner according to a fifth aspect of the present invention is the air conditioner according to any of the first to fourth aspects, wherein a plurality of utilization units are connected to the heat source unit. The operation control means performs a pipe length judgment operation for one of a plurality of usage units. In this air conditioner, a plurality of use units are connected to the heat source unit, and when calculating the pipe length of the refrigerant communication pipe, the pipe length judgment operation is performed for one of the plurality of use units. Therefore, the propagation time can be accurately detected without any disturbance on the other usage unit side.

 [0009] An air conditioner according to a sixth aspect of the invention is the air conditioner according to any of the first to fifth aspects of the invention, wherein the pipe length calculation means is a relationship between the propagation time and the pipe length of the refrigerant communication pipe. Calculate the refrigerant communication pipe length from the equation and calculate the refrigerant communication pipe diameter from the refrigerant communication pipe diameter obtained from the information of the units that make up the refrigerant circuit and the refrigerant communication pipe length calculated using the relational expression. The volume of is calculated.

 In this air conditioner, the pipe length of the refrigerant communication pipe is calculated from the propagation time detected in the pipe length judgment operation using the relational expression between the propagation time and the pipe length of the refrigerant communication pipe, and the calculated pipe length and Information capacity of the usage unit Pipe diameter and force of the refrigerant communication pipe obtained The volume of the refrigerant communication pipe is calculated, so the effort to input the information of the refrigerant communication pipe is reduced, and the volume of the refrigerant communication pipe is reduced. Can be calculated accurately

[0010] An air conditioner according to a seventh invention is the air according to any of the first to sixth inventions. In the harmony device, the refrigerant amount for determining the adequacy of the refrigerant amount in the refrigerant circuit using the pipe length of the refrigerant communication pipe calculated by the pipe length calculating means and the operating state quantity of the refrigerant flowing through the refrigerant circuit or the component device The determination unit is further provided.

 In this air conditioner, the suitability of the refrigerant amount in the refrigerant circuit is determined by using the pipe length of the refrigerant communication pipe calculated by the pipe length calculating means and the operating state quantity of the refrigerant flowing through the refrigerant circuit or the component equipment. As a result, it is possible to obtain the length of the refrigerant communication pipe while reducing the effort of inputting the information of the refrigerant communication pipe, and as a result, to determine the suitability of the amount of the refrigerant in the refrigerant circuit with high accuracy. Can do.

 Brief Description of Drawings

 FIG. 1 is a schematic configuration diagram of an air conditioner according to a first embodiment of the present invention.

 FIG. 2 is a control block diagram of the air conditioner according to the first embodiment.

 FIG. 3 is a flowchart of a test operation mode.

 FIG. 4 is a flowchart of an automatic refrigerant charging operation.

 FIG. 5 is a schematic diagram showing the state of refrigerant flowing in the refrigerant circuit in the refrigerant quantity determination operation (illustration of a four-way switching valve and the like is omitted).

 FIG. 6 is a flowchart of pipe length judgment operation.

 FIG. 7 is a diagram showing changes over time in the degree of opening of the indoor expansion valve and the compressor suction superheat degree in the pipe length judgment operation.

 [FIG. 8] A table showing comparison data of indoor unit models, relational expressions between pipe length and propagation time, pipe diameter (gas), and pipe diameter (liquid).

 FIG. 9 is a flowchart of an initial refrigerant quantity determination operation.

 FIG. 10 is a flowchart of a refrigerant leak detection operation mode.

 FIG. 11 is a schematic configuration diagram of an air conditioner according to a second embodiment of the present invention.

 FIG. 12 is a control block diagram of the air conditioner according to the second embodiment.

 Explanation of symbols

[0012] 1, 101 air conditioner

 2 Outdoor unit (heat source unit)

4, 5 Indoor unit (Usage unit) 6 Liquid refrigerant communication pipe (Refrigerant communication pipe)

 7 Gas refrigerant communication pipe (refrigerant communication pipe)

 10, 110 Refrigerant circuit

 21 Compressor

 23 Outdoor heat exchanger (heat source side heat exchanger)

 25 Supercooler (Temperature adjustment mechanism)

 41, 51 Indoor expansion valve (expansion mechanism)

 42, 52 Indoor heat exchange (use side heat exchange)

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of an air conditioner according to the present invention will be described based on the drawings.

 [First embodiment]

 (1) Configuration of air conditioner

 FIG. 1 is a schematic configuration diagram of an air-conditioning apparatus 1 according to the first embodiment of the present invention. The air conditioner 1 is an apparatus used for air conditioning in a room such as a building by performing a vapor compression refrigeration cycle operation. The air conditioner 1 is mainly composed of an outdoor unit 2 as one heat source unit, an indoor unit 4 as one utilization unit, and a liquid refrigerant as a refrigerant communication pipe connecting the outdoor unit 2 and the indoor unit 4. Connecting pipe 6 and gas refrigerant connecting pipe 7 are provided. That is, the vapor compression refrigerant circuit 10 of the air conditioner 1 of the present embodiment is configured by connecting the outdoor unit 2, the indoor unit 4, the liquid refrigerant communication pipe 6, and the gas refrigerant communication pipe 7. Has been.

[0014] <Indoor unit>

 The indoor unit 4 is installed by being embedded or suspended in the ceiling of a room such as a building or by hanging on the wall surface of the room. The indoor unit 4 is connected to the outdoor unit 2 via the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7 and constitutes a part of the refrigerant circuit 10.

 Next, the configuration of the indoor unit 4 will be described.

The indoor unit 4 mainly includes an indoor refrigerant circuit 10a that forms part of the refrigerant circuit 10. Have. This indoor refrigerant circuit 10a mainly has an indoor expansion valve 41 as an expansion mechanism and an indoor heat exchanger 42 as a use side heat exchanger.

 In the present embodiment, the indoor expansion valve 41 is an electric expansion valve connected to the liquid side of the indoor heat exchanger 42 in order to adjust the flow rate of the refrigerant flowing in the indoor refrigerant circuit 10a.

 In the present embodiment, the indoor heat exchange is a cross-fin type fin 'and' tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant evaporator during cooling operation. It is a heat exchanger that functions as a refrigerant condenser during heating operation to heat indoor air.

 In the present embodiment, the indoor unit 4 sucks indoor air into the unit, exchanges heat with the refrigerant in the indoor heat exchanger 42, and then supplies the indoor fan 43 as a blower fan to be supplied indoors as supply air. Have. The indoor fan 43 is a fan capable of changing the air volume Wr of air supplied to the indoor heat exchanger 42, and in this embodiment, the centrifugal fan or the multiblade fan driven by the motor 43a that also has DC fan motor power. Etc.

The indoor unit 4 is provided with various sensors. On the liquid side of the indoor heat exchanger 42, a liquid side temperature sensor 44 that detects the temperature of the refrigerant (that is, the refrigerant temperature corresponding to the condensation temperature Tc during heating operation or the evaporation temperature Te during cooling operation) is provided. ing. A gas side temperature sensor 45 for detecting the refrigerant temperature Teo is provided on the gas side of the indoor heat exchanger 42. An indoor temperature sensor 46 for detecting the temperature of indoor air flowing into the unit (that is, the indoor temperature Tr) is provided on the indoor air inlet side of the indoor unit 4. In the present embodiment, the liquid side temperature sensor 44, the gas side temperature sensor 45, and the room temperature sensor 46 are composed of thermistors. The indoor unit 4 also has an indoor side control unit 47 that controls the operation of each part constituting the indoor unit 4. The indoor control unit 47 includes a microcomputer, a memory, and the like provided for controlling the indoor unit 4, and a remote controller (not shown) for individually operating the indoor unit 4. Control signals etc. can be exchanged with the outdoor unit 2 and control signals etc. can be exchanged with the outdoor unit 2 via the transmission line 8a. [0016] <Outdoor unit>

 The outdoor unit 2 is installed outside a building or the like, and is connected to the indoor unit 4 via the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7, and the refrigerant circuit 10 is connected between the indoor units 4. It is composed.

 Next, the configuration of the outdoor unit 2 will be described. The outdoor unit 2 mainly has an outdoor refrigerant circuit 10c that constitutes a part of the refrigerant circuit 10. This outdoor refrigerant circuit 10c mainly includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23 as a heat source side heat exchange, an outdoor expansion valve 38 as an expansion mechanism, an accumulator 24, A supercooler 25 as a temperature adjusting mechanism, a liquid side closing valve 26 and a gas side closing valve 27 are provided.

 The compressor 21 is a compressor whose operating capacity can be varied. In this embodiment, the compressor 21 is a positive displacement compressor driven by a motor 21a whose rotational speed Rm is controlled by an inverter. In the present embodiment, the number of the compressors 21 is only one, but is not limited to this, and two or more compressors may be connected in parallel according to the number of indoor units connected.

 [0017] The four-way switching valve 22 is a valve for switching the direction of the refrigerant flow. During the cooling operation, the outdoor heat exchanger 23 is used as a refrigerant condenser compressed by the compressor 21, and the indoor In order for the heat exchanger 42 to function as an evaporator for the refrigerant condensed in the outdoor heat exchanger 23, the discharge side of the compressor 21 and the gas side of the outdoor heat exchanger 23 are connected and the suction side of the compressor 21 (specifically Specifically, the accumulator 24) is connected to the gas refrigerant communication pipe 7 side (see the solid line of the four-way selector valve 22 in FIG. 1), and the indoor heat exchanger 42 is compressed by the compressor 21 during heating operation. In order to function as a refrigerant condenser and an outdoor heat exchanger as a refrigerant evaporator condensed in the indoor heat exchanger 42, the discharge side of the compressor 21 and the gas refrigerant communication pipe 7 side are connected and compressed. Connect the suction side of unit 21 to the gas side of outdoor heat exchanger 23. (Refer to the broken line of the four-way switching valve 22 in FIG. 1).

[0018] In the present embodiment, the outdoor heat exchange is a cross-fin type fin 'and' tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant condenser during cooling operation. This is heat exchange that functions as a refrigerant evaporator during heating operation. The outdoor heat exchanger 23 has its gas side connected to the four-way selector valve 22 and its liquid side liquid-cooled. Connected to the medium communication pipe 6.

 In the present embodiment, the outdoor expansion valve 38 is an electric expansion valve connected to the liquid side of the outdoor heat exchanger 23 in order to adjust the pressure and flow rate of the refrigerant flowing in the outdoor refrigerant circuit 10c.

 In the present embodiment, the outdoor unit 2 has an outdoor fan 28 as a blower fan for sucking outdoor air into the unit, exchanging heat with the refrigerant in the outdoor heat exchanger 23, and then discharging the air outside. ing. The outdoor fan 28 is a fan capable of changing the air volume Wo of the air supplied to the outdoor heat exchanger ^ 23. In this embodiment, the outdoor fan 28 is a propeller fan or the like driven by a motor 28a having a DC fan motor power. is there.

[0019] The accumulator 24 is connected between the four-way switching valve 22 and the compressor 21, and stores excess refrigerant generated in the refrigerant circuit 10 in accordance with fluctuations in the operating load of the indoor unit 4. It is a container that can.

 In this embodiment, the supercooler 25 is a double-pipe heat exchanger, and is provided to cool the refrigerant that is condensed in the outdoor heat exchanger 23 and then sent to the indoor expansion valve 41. It has been. In the present embodiment, the supercooler 25 is connected between the outdoor expansion valve 38 and the liquid side closing valve 26.

 In the present embodiment, a bypass refrigerant circuit 61 as a cooling source for the subcooler 25 is provided. In the following description, the part excluding the bypass refrigerant circuit 61 from the refrigerant circuit 10 will be referred to as a main refrigerant circuit for convenience.

[0020] The bypass refrigerant circuit 61 is connected to the main refrigerant circuit so that a main part of the refrigerant sent from the outdoor heat exchanger to the indoor expansion valve 41 is branched to return to the suction side of the compressor 21. . Specifically, the bypass refrigerant circuit 61 is connected so that part of the refrigerant sent from the outdoor expansion valve 38 to the indoor expansion valve 41 also branches the positional force between the outdoor heat exchanger and the subcooler 25. And a junction circuit 61b connected to the suction side of the compressor 21 so as to return from the outlet on the bypass refrigerant circuit side of the subcooler 25 to the suction side of the compressor 21. The branch circuit 61a is provided with a bypass expansion valve 62 for adjusting the flow rate of the refrigerant flowing through the bypass refrigerant circuit 61. Here, the bypass expansion valve 62 also has an electric expansion valve force. As a result, it is sent from the outdoor heat exchange to the indoor expansion valve 41. In the supercooler 25, the refrigerant that is cooled is cooled by the refrigerant that flows through the bypass refrigerant circuit 61 after being depressurized by the bypass expansion valve 62. That is, the capacity control of the subcooler 25 is performed by adjusting the opening degree of the bypass expansion valve 62.

 The liquid side shutoff valve 26 and the gas side shutoff valve 27 are valves provided at connection ports with external devices and pipes (specifically, the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7). The liquid side closing valve 26 is connected to the outdoor heat exchanger 23. The gas side closing valve 27 is connected to the four-way switching valve 22.

The outdoor unit 2 is provided with various sensors. Specifically, the outdoor unit 2 includes a suction pressure sensor 29 that detects the suction pressure Ps of the compressor 21, a discharge pressure sensor 30 that detects the discharge pressure Pd of the compressor 21, and the compressor 21. A suction temperature sensor 31 for detecting the suction temperature Ts and a discharge temperature sensor 32 for detecting the discharge temperature Td of the compressor 21 are provided. The suction temperature sensor 31 is provided at a position between the accumulator 24 and the compressor 21. The outdoor heat exchanger 23 includes a heat exchange temperature sensor that detects the temperature of the refrigerant flowing in the outdoor heat exchanger 23 (that is, the refrigerant temperature corresponding to the condensation temperature Tc during the cooling operation or the evaporation temperature Te during the heating operation). 33 is provided. On the liquid side of the outdoor heat exchanger 23, a liquid side temperature sensor 34 for detecting the temperature Tco of the refrigerant is provided. A liquid pipe temperature sensor 35 that detects the temperature of the refrigerant (that is, the liquid pipe temperature Tip) is provided at the outlet of the subcooler 25 on the main refrigerant circuit side. The junction circuit 6 lb of the no-pass refrigerant circuit 61 is provided with a bypass temperature sensor 63 for detecting the temperature of the refrigerant flowing through the outlet of the subcooler 25 on the bypass refrigerant circuit side. An outdoor temperature sensor 36 for detecting the temperature of the outdoor air flowing into the unit (that is, the outdoor temperature Ta) is provided on the outdoor air inlet side of the outdoor unit 2. In the present embodiment, the suction temperature sensor 31, the discharge temperature sensor 32, the heat exchange temperature sensor 33, the liquid side temperature sensor 34, the liquid pipe temperature sensor 35, the outdoor temperature sensor 36, and the binos temperature sensor 63 are composed of thermistors. The outdoor unit 2 also has an outdoor control unit 37 that controls the operation of each part constituting the outdoor unit 2. The outdoor control unit 37 includes a microcomputer provided for controlling the outdoor unit 2, a memory, an inverter circuit for controlling the motor 21a, and the like, and an indoor control unit 47 of the indoor unit 4 Control signals, etc., between them via transmission line 8a Is getting ready to do. That is, the control unit 8 that controls the operation of the entire air conditioner 1 is configured by the indoor control unit 47, the outdoor control unit 37, and the transmission line 8a that connects the control units 37 and 47.

[0022] As shown in FIG. 2, the control unit 8 is connected so as to receive detection signals of various sensors 29 to 36, 44 to 46, and 63, and based on these detection signals and the like. It is connected so that various devices and valves 21, 22, 24, 28a, 38, 41, 43a, 62 can be controlled. Also, the control unit 8 is connected with a warning display unit 9 that is an LED or the like for notifying that a refrigerant leak has been detected in the refrigerant leak detection operation described later. Here, FIG. 2 is a control block diagram of the air conditioner 1.

 <Refrigerant piping>

 Refrigerant communication pipes 6 and 7 are refrigerant pipes that are installed on site when the air conditioner 1 is installed in a building or other location, such as a combination of the installation location or outdoor unit and indoor unit. Depending on the installation conditions, those having various lengths and pipe diameters are used. For this reason, for example, when a new air conditioner is installed, it is necessary to accurately grasp information such as the length of the refrigerant communication pipes 6 and 7 in order to calculate the refrigerant charge amount. Therefore, the calculation of the refrigerant amount is complicated. In addition, when the existing unit is used to update the indoor unit or the outdoor unit, information such as the diameter of the refrigerant communication pipes 6 and 7 may be lost.

[0023] As described above, the indoor refrigerant circuit 10a, the outdoor refrigerant circuit 10c, and the refrigerant communication pipes 6 and 7 are connected to form the refrigerant circuit 10 of the air conditioner 1. In other words, the refrigerant circuit 10 is composed of a bypass refrigerant circuit 61 and a main refrigerant circuit excluding the bypass refrigerant circuit 61. The air conditioner 1 of the present embodiment includes a four-way switching valve by a control unit 8 including an indoor side control unit 47, an outdoor side control unit 37, and a transmission line 8a that connects the control units 37 and 47. The operation is switched between the cooling operation and the heating operation by 22 and the devices of the outdoor unit 2 and the indoor unit 4 are controlled according to the operation load of the indoor unit 4.

 (2) Operation of the air conditioner

Next, the operation of the air conditioner 1 of the present embodiment will be described. [0024] The operation mode of the air conditioner 1 of the present embodiment includes a normal operation mode for controlling the components of the outdoor unit 2 and the indoor unit 4 in accordance with the operation load of the indoor unit 4, and the air conditioner 1 After installation of component equipment (specifically, not limited to after installation of the first equipment, for example, after modification such as addition or removal of component equipment such as indoor units, or after repair of equipment failure) There are a test operation mode for performing the test operation to be performed and a refrigerant leak detection operation mode for determining whether or not the refrigerant leaks from the refrigerant circuit 10 after the test operation is finished and the normal operation is started. The normal operation mode mainly includes a cooling operation for cooling the room and a heating operation for heating the room. The test operation mode mainly includes an automatic refrigerant filling operation for filling the refrigerant in the refrigerant circuit 10, a pipe length determination operation for detecting the pipe length of the refrigerant communication pipes 6 and 7, and after the installation of the constituent devices or the refrigerant And an initial refrigerant quantity detection operation for detecting the initial refrigerant quantity after the refrigerant is filled in the circuit.

 [0025] Hereinafter, the operation of each operation mode of the air conditioner 1 will be described.

 <Normal operation mode>

 (Cooling operation)

First, the cooling operation in the normal operation mode will be described with reference to FIGS. 1 and 2. During the cooling operation, the four-way switching valve 22 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 21 is the outdoor heat. It is connected to the gas side of the exchanger 23, and the suction side of the compressor 21 is connected to the gas side of the indoor heat exchanger 42 via the gas side closing valve 27 and the gas refrigerant communication pipe 7. The outdoor expansion valve 38 is fully opened. The liquid side closing valve 26 and the gas side closing valve 27 are opened. The opening of the indoor expansion valve 41 is adjusted so that the superheat degree SHr of the refrigerant at the outlet of the indoor heat exchanger 42 (that is, the gas side of the indoor heat exchanger 42) becomes constant at the superheat degree target value SHrs. It has become. In the present embodiment, the superheat degree SHr of the refrigerant at the outlet of the indoor heat exchanger 42 is calculated from the refrigerant temperature value detected by the gas side temperature sensor 45 to the refrigerant temperature value detected by the liquid side temperature sensor 44 (evaporation temperature Te The suction pressure Ps of the compressor 21 detected by the suction pressure sensor 29, or the saturation temperature value corresponding to the evaporation temperature Te. This is detected by subtracting the saturation temperature value of the refrigerant from the refrigerant temperature value detected by the gas side temperature sensor 45. Although not adopted in this embodiment, a temperature sensor for detecting the temperature of the refrigerant flowing in the indoor heat exchanger 42 is provided, and the refrigerant temperature value corresponding to the evaporation temperature Te detected by this temperature sensor is By subtracting the refrigerant temperature value detected by the gas side temperature sensor 45, the superheat degree SHr of the refrigerant at the outlet of the indoor heat exchange may be detected. Further, the opening of the bypass expansion valve 62 is adjusted so that the superheat degree SHb of the refrigerant at the outlet of the supercooler 25 on the bypass refrigerant circuit side becomes the superheat degree target value SHbs. In the present embodiment, the superheat degree SHb of the refrigerant at the outlet of the bypass refrigerant circuit side of the supercooler 25 is the saturation temperature value corresponding to the evaporation temperature Te, which is the suction pressure Ps of the compressor 21 detected by the suction pressure sensor 29. The refrigerant temperature value force detected by the bypass temperature sensor 63 is also detected by subtracting the saturation temperature value of this refrigerant. Although not adopted in this embodiment, a temperature sensor is provided at the inlet of the supercooler 25 on the binos refrigerant circuit side, and the refrigerant temperature value detected by this temperature sensor is detected by the bypass temperature sensor 63. By subtracting the temperature value force, the superheat degree SHb of the refrigerant at the outlet of the subcooler 25 on the bypass refrigerant circuit side may be detected.

When the compressor 21, the outdoor fan 28, and the indoor fan 43 are started in the state of the refrigerant circuit 10, the low-pressure gas refrigerant is sucked into the compressor 21 and compressed to become a high-pressure gas refrigerant. Thereafter, the high-pressure gas refrigerant is sent to the outdoor heat exchanger 23 via the four-way switching valve 22, exchanges heat with the outdoor air supplied by the outdoor fan 28, and condenses to condense. It becomes. Then, the high-pressure liquid refrigerant passes through the outdoor expansion valve 38 and flows into the supercooler 25, and is further cooled by exchanging heat with the refrigerant flowing through the bypass refrigerant circuit 61 to be in a supercooled state. At this time, a part of the high-pressure liquid refrigerant condensed in the outdoor heat exchange is branched to the no-pass refrigerant circuit 61, and after being depressurized by the bypass expansion valve 62, is returned to the suction side of the compressor 21. Here, a part of the refrigerant passing through the binos expansion valve 62 is evaporated by being reduced to near the suction pressure Ps of the compressor 21. The outlet force of the bypass expansion valve 62 of the bypass refrigerant circuit 61 also flows toward the suction side of the compressor 21, passes through the subcooler 25, and passes from the outdoor heat exchanger 23 on the main refrigerant circuit side to the indoor refrigerant. Tsu Heat exchange with high-pressure liquid refrigerant sent to

[0027] Then, the high-pressure liquid refrigerant in a supercooled state is sent to the indoor unit 4 via the liquid side closing valve 26 and the liquid refrigerant communication pipe 6. The high-pressure liquid coolant sent to the indoor unit 4 is reduced to near the suction pressure Ps of the compressor 21 by the indoor expansion valve 41 to become a low-pressure gas-liquid two-phase refrigerant and sent to the indoor heat exchanger. In the heat exchange in the room, heat is exchanged with the room air to evaporate into a low-pressure gas refrigerant.

 This low-pressure gas refrigerant is sent to the outdoor unit 2 via the gas refrigerant communication pipe 7 and flows into the accumulator 24 via the gas side closing valve 27 and the four-way switching valve 22. Then, the low-pressure gas refrigerant that has flowed into the accumulator 24 is again sucked into the compressor 21.

 (Heating operation)

 Next, the heating operation in the normal operation mode will be described.

[0028] During the heating operation, the four-way switching valve 22 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the indoor heat exchanger 42 via the gas-side stop valve 27 and the gas refrigerant communication pipe 7. And the suction side of the compressor 21 is connected to the gas side of the outdoor heat exchanger 23. The degree of opening of the outdoor expansion valve 38 is adjusted so as to reduce the refrigerant flowing into the outdoor heat exchanger 23 to a pressure at which the refrigerant can evaporate in the outdoor heat exchanger 23 (that is, the evaporation pressure Pe). . Further, the liquid side closing valve 26 and the gas side closing valve 27 are opened. The opening degree of the indoor expansion valve 41 is adjusted so that the degree of supercooling SCr of the refrigerant at the outlet of the indoor heat exchange becomes constant at the supercooling degree target value SCrs. In the present embodiment, the refrigerant subcooling degree SCr at the outlet of the indoor heat exchanger 42 is converted from the discharge pressure Pd of the compressor 21 detected by the discharge pressure sensor 30 to a saturation temperature value corresponding to the condensation temperature Tc, The refrigerant is detected by subtracting the refrigerant temperature value detected by the liquid temperature sensor 44. In this embodiment, a temperature sensor for detecting the temperature of the refrigerant flowing in the indoor heat exchanger is provided, and the refrigerant temperature value corresponding to the condensation temperature Tc detected by the temperature sensor is set as follows. The subcooling degree SCr of the refrigerant at the outlet of the indoor heat exchanger 42 may be detected by subtracting the refrigerant temperature value detected by the liquid side temperature sensor 44. The bypass expansion valve 62 is closed. [0029] When the compressor 21, the outdoor fan 28, and the indoor fan 43 are started in the state of the refrigerant circuit 10, the low-pressure gas refrigerant is sucked into the compressor 21 and compressed to become a high-pressure gas refrigerant. It is sent to the indoor unit 4 via the four-way switching valve 22, the gas side closing valve 27 and the gas refrigerant communication pipe 7.

 The high-pressure gas refrigerant sent to the indoor unit 4 is condensed by exchanging heat with the indoor air in the outdoor heat exchanger 42 to become a high-pressure liquid refrigerant, and then passes through the indoor expansion valve 41. At this time, the pressure is reduced according to the opening degree of the indoor expansion valve 41.

 The refrigerant that has passed through the indoor expansion valve 41 is sent to the outdoor unit 2 via the liquid refrigerant communication pipe 6 and further depressurized via the liquid side closing valve 26, the subcooler 25, and the outdoor expansion valve 38. After that, it flows into the outdoor heat exchanger 23. The low-pressure gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 23 exchanges heat with the outdoor air supplied by the outdoor fan 28 to evaporate into a low-pressure gas refrigerant. Flows into the accumulator 24. Then, the low-pressure gas refrigerant flowing into the accumulator 24 is again sucked into the compressor 21.

 [0030] The operation control in the normal operation mode as described above is performed by the control unit 8 (more specifically, the indoor side control unit 47 and the room functioning as normal operation control means for performing normal operation including cooling operation and heating operation). This is performed by the transmission line 8a) connecting the outer control unit 37 and the control units 37 and 47.

 <Test run mode>

 Next, the trial operation mode will be described with reference to FIGS. Here, Fig. 3 is a flowchart of the test operation mode. In the present embodiment, in the test operation mode, first, the automatic refrigerant charging operation in step S1 is performed, then the pipe length determination operation in step S2 is performed, and further, the initial refrigerant amount detection operation in step S3 is performed. .

 In the present embodiment, the outdoor unit 2 pre-filled with the refrigerant and the indoor unit 4 are installed at an installation location such as a building and connected via the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7 to form the refrigerant circuit 10. An example in which the refrigerant circuit 10 is additionally filled with a refrigerant that is insufficient in accordance with the volumes of the liquid refrigerant communication pipe 6 and the gas refrigerant communication pipe 7 after the above-described configuration will be described.

[0031] (Step S1: Automatic refrigerant charging operation) First, the liquid side shutoff valve 26 and the gas side shutoff valve 27 of the outdoor unit 2 are opened, and the refrigerant circuit 10 is filled with the refrigerant filled in the outdoor unit 2 in advance.

 Next, an operator who performs a test run connects a refrigerant cylinder for additional charging to a service port (not shown) of the refrigerant circuit 10 and directly or remotely controls the control unit 8. When a command to start a trial run from a remote location is issued, the control unit 8 performs steps S11 to S13 shown in FIG. Here, FIG. 4 is a flowchart of the automatic refrigerant charging operation.

 (Step S11: Refrigerant amount judgment operation)

 When a command to start the automatic refrigerant charging operation is issued, the refrigerant circuit 10 is in a state where the four-way switching valve 22 of the outdoor unit 2 is shown by the solid line in FIG. 1 and the indoor expansion valve 41 and the outdoor unit of the indoor unit 4 The expansion valve 38 is opened, the compressor 21, the outdoor fan 28, and the indoor fan 43 are started, and the cooling operation is performed.

Then, as shown in FIG. 5, in the refrigerant circuit 10, the high-pressure gas refrigerant compressed and discharged in the compressor 21 flows through the flow path from the compressor 21 to the outdoor heat exchange functioning as a condenser ( (Refer to the hatched part in Fig. 5 from the compressor 21 to the outdoor heat exchanger 23), and the outdoor heat exchanger 23 functioning as a condenser is changed from a gas state to a liquid state by heat exchange with the outdoor air. (Refer to the portion corresponding to the outdoor heat exchanger 23 in the hatched and black hatched portions in FIG. 5), and the flow from the outdoor heat exchanger 23 to the indoor expansion valve 41 High-pressure liquid refrigerant flows through the flow path including the outdoor expansion valve 38, the part on the main refrigerant circuit side of the subcooler 25 and the liquid refrigerant communication pipe 6 and the flow path from the outdoor heat exchanger 23 to the bypass expansion valve 62. (Outdoor heat in the black-hatched area in Figure 5 (Refer to the part from the inversion 23 to the indoor expansion valve 41 and the bypass expansion valve 62), the indoor heat exchange part functioning as an evaporator and the bypass refrigerant circuit side part of the subcooler 25 Low-pressure refrigerant that changes phase into a gas-liquid phase due to heat exchange flows (the indoor heat exchanger 42 part and the supercooler 25 part in the grid-like hatched and hatched parts in Fig. 5) ), The flow path including the gas refrigerant communication pipe 7 and the accumulator 24 from the indoor heat exchanger 42 to the compressor 21 and the partial force on the bypass refrigerant circuit side of the subcooler 25 are also included in the flow path to the compressor 21. Low pressure gas The refrigerant begins to flow (the hatched portion in Fig. 5 is the portion from the indoor heat exchanger 42 to the compressor 21 and the partial force on the bypass refrigerant circuit side of the subcooler 25 is also the portion up to the compressor 21. See). FIG. 5 is a schematic diagram showing the state of the refrigerant flowing in the refrigerant circuit 10 in the refrigerant quantity determination operation (illustration of the four-way switching valve 22 and the like is omitted).

 Next, the following device control is performed to shift to an operation for stabilizing the state of the refrigerant circulating in the refrigerant circuit 10. Specifically, the indoor expansion valve 41 is controlled so that the superheat degree SHr of the indoor heat exchanger 42 functioning as an evaporator becomes constant (hereinafter referred to as superheat degree control) so that the evaporation pressure Pe becomes constant. Then, the operation capacity of the compressor 21 is controlled (hereinafter referred to as evaporation pressure control) and supplied to the outdoor heat exchanger 23 by the outdoor fan 28 so that the refrigerant condensing pressure Pc in the outdoor heat exchange becomes constant. Controls the air volume Wo of the outdoor air (hereinafter referred to as condensing pressure control) and controls the capacity of the subcooler 25 so that the temperature of the refrigerant sent from the subcooler 25 to the indoor expansion valve 41 is constant ( In the following, the liquid pipe temperature control is performed), and the indoor fan 43 supplies the indoor heat exchange to the indoor heat exchanger ^ 42 so that the evaporation pressure Pe of the refrigerant is stably controlled by the above-described evaporation pressure control. Air volume Wr is kept constant.

Here, the evaporation pressure control is performed in the indoor heat exchanger 42 functioning as an evaporator, in a gas-liquid two-phase state force by heat exchange with room air, and a low-pressure cooling while changing phase to a gas state. Refrigerant in the indoor heat exchanger 42 through which the medium flows (refer to the portion corresponding to the indoor heat exchanger 42 in the grid-shaped hatched and hatched portions in FIG. 5 and hereinafter referred to as the evaporator section C). The amount is also a force that greatly affects the evaporation pressure Pe of the refrigerant. And here, by controlling the operating capacity of the compressor 21 by the motor 21a whose rotation speed Rm is controlled by the inverter, the evaporation pressure Pe of the refrigerant in the indoor heat exchanger 42 is made constant, and the evaporator section C The state of the refrigerant flowing inside is stabilized, and a state in which the amount of refrigerant in the evaporator C is changed mainly by the evaporation pressure Pe is created. In the control of the evaporation pressure Pe by the compressor 21 of the present embodiment, the refrigerant temperature value (corresponding to the evaporation temperature Te) detected by the liquid side temperature sensor 44 of the indoor heat exchanger 42 is converted into a saturation pressure value. Thus, the operating capacity of the compressor 21 is controlled so that the pressure value becomes constant at the low pressure target value Pes (that is, control for changing the rotational speed Rm of the motor 21a), and the refrigerant circuit 10 This is achieved by increasing or decreasing the amount of refrigerant circulating in the interior, Wc. In this embodiment, it is adopted However, the suction pressure Ps of the compressor 21 detected by the suction pressure sensor 29, which is an operation state quantity equivalent to the refrigerant pressure at the refrigerant evaporating pressure Pe in the indoor heat exchange, is the low pressure target value Pes. Or the operating capacity of the compressor 21 may be controlled so that the saturation temperature value corresponding to the suction pressure Ps (corresponding to the evaporation temperature Te) becomes constant at the low pressure target value Tes. The operating capacity of the compressor 21 is controlled so that the refrigerant temperature value (corresponding to the evaporation temperature Te) detected by the liquid side temperature sensor 44 of the indoor heat exchanger 42 is constant at the low pressure target value Tes. Also good.

By performing such evaporation pressure control, the gas refrigerant communication pipe 7 from the indoor heat exchanger 42 to the compressor 21 and the refrigerant pipe including the accumulator 24 (in the hatched portion in FIG. The state of the refrigerant flowing through the heat exchanger 42 to the compressor 21 (hereinafter referred to as “gas refrigerant circulation part D”) is also stable and is mainly operated equivalent to the refrigerant pressure in the gas refrigerant circulation part D. A state in which the amount of refrigerant in the gas refrigerant circulation portion D is changed by the evaporation amount Pe (that is, the suction pressure Ps), which is a state quantity, is created. Condensation pressure control is also performed in the outdoor heat exchanger ^^ 23 in which high-pressure refrigerant flows while changing the gas state force to the liquid state due to heat exchange with the outdoor air (hatched hatched and blackened in Fig. 5). Among the hatched portions, see the portion corresponding to the outdoor heat exchanger 23 (hereinafter referred to as the condenser portion A), which is also the force that greatly affects the refrigerant condensing pressure Pc. Since the refrigerant condensing pressure Pc in the condenser part A changes greatly due to the influence of the outdoor temperature Ta, the air volume Wo of the indoor air supplied from the outdoor fan 28 to the outdoor heat exchanger 23 is controlled by the motor 28a. As a result, the condensation pressure Pc of the refrigerant in the outdoor heat exchanger 23 is made constant, and the state of the refrigerant flowing in the condenser section A is stabilized, and mainly the liquid side of the outdoor heat exchanger 23 (hereinafter referred to as the refrigerant). In the description of the quantity determination operation, the refrigerant amount in the condenser A is changed by the degree of supercooling SCo at the outlet of the outdoor heat exchanger 23). In the control of the condensation pressure Pc by the outdoor fan 28 of the present embodiment, the compressor 21 detected by the discharge pressure sensor 30 which is an operation state amount equivalent to the refrigerant condensation pressure Pc in the outdoor heat exchanger 23 is used. The discharge pressure Pd or the temperature of the refrigerant flowing in the outdoor heat exchanger 23 detected by the heat exchange temperature sensor 33 (that is, the condensation temperature Tc) is used. [0036] Then, by performing such condensing pressure control, the outdoor expansion valve 38 from the outdoor heat exchange to the indoor expansion valve 41, the portion on the main refrigerant circuit side of the subcooler 25, and the liquid refrigerant communication pipe 6 The high-pressure liquid refrigerant flows through the flow path including the outdoor heat exchanger 23 and the flow path from the outdoor heat exchanger 23 to the bypass expansion valve 62 of the bypass refrigerant circuit 61. From the outdoor heat exchanger 23 to the indoor expansion valve 41 and the bypass expansion valve 62 (Refer to the black hatched area in Fig. 5; hereinafter referred to as liquid refrigerant circulation section B) The refrigerant pressure is also stable and liquid refrigerant circulation section B is sealed with liquid refrigerant and stabilized It becomes.

 The liquid pipe temperature control is performed in the refrigerant pipe including the liquid refrigerant communication pipe 6 from the subcooler 25 to the indoor expansion valve 41 (the subcooler 25 in the liquid refrigerant circulation section B shown in FIG. 5). To the indoor expansion valve 41)) so that the refrigerant density does not change. The capacity control of the subcooler 25 is performed by adjusting the refrigerant temperature Tip detected by the liquid pipe temperature sensor 35 provided at the outlet of the main refrigerant circuit of the subcooler 25 to the liquid pipe temperature target value Tips. This is realized by increasing or decreasing the flow rate of the refrigerant flowing through the bypass refrigerant circuit 61 so as to adjust the amount of exchange heat between the refrigerant flowing through the main refrigerant circuit side of the subcooler 25 and the refrigerant flowing through the bypass refrigerant circuit side. ing. The flow rate of the refrigerant flowing through the bypass refrigerant circuit 61 is increased or decreased by adjusting the opening degree of the bypass expansion valve 62. In this way, liquid pipe temperature control is realized in which the refrigerant temperature in the refrigerant pipe including the liquid refrigerant communication pipe 6 extending from the supercooler 25 to the indoor expansion valve 41 is constant.

 [0037] Then, by performing such liquid pipe temperature constant control, as the refrigerant amount in the refrigerant circuit 10 gradually increases by charging the refrigerant circuit 10 with the refrigerant, the outdoor heat exchange 23 The refrigerant temperature Tco at the outlet of the outdoor heat exchanger 23 is changed even when the refrigerant temperature Tco at the outlet of the outdoor heat exchanger 23 changes (that is, the degree of refrigerant supercooling SCo at the outlet of the outdoor heat exchanger 23). The influence of this change and the outlet force of the outdoor heat exchange are also contained only in the refrigerant pipe reaching the subcooler 25, and the refrigerant from the subcooler 25 to the indoor expansion valve 41 including the liquid refrigerant communication pipe 6 in the liquid refrigerant circulation section B The pipe is not affected.

Further, the superheat control is performed because the amount of refrigerant in the evaporator section C greatly affects the dryness of the refrigerant at the outlet of the indoor heat exchanger 42. The degree of superheat SHr of the refrigerant at the outlet of the indoor heat exchange is controlled by controlling the opening degree of the indoor expansion valve 41. The superheat degree SHr of the refrigerant on the gas side of the indoor heat exchanger 42 (hereinafter referred to as the outlet of the indoor heat exchanger 42 in the description of the refrigerant quantity determination operation) is made constant at the superheat degree target value SHrs (that is, The gas refrigerant at the outlet of the indoor heat exchanger 42 is overheated), and the state of the refrigerant flowing in the evaporator section C is stabilized.

 [0038] Then, by performing such superheat degree control, a state in which the gas refrigerant surely flows in the gas refrigerant communication portion D is created.

 By the various controls described above, the state of the refrigerant circulating in the refrigerant circuit 10 is stabilized, and the distribution of the refrigerant amount in the refrigerant circuit 10 becomes constant. When the refrigerant begins to be charged, it is possible to create a state in which the change in the refrigerant amount in the refrigerant circuit 10 mainly appears as a change in the refrigerant amount in the outdoor heat exchanger 23 (hereinafter, this operation is performed). Is the refrigerant quantity determination operation).

 The above control is performed by the control unit 8 (more specifically, between the indoor side control unit 47, the outdoor side control unit 37, and the control units 37, 47 functioning as a refrigerant amount determination operation control means for performing the refrigerant amount determination operation. This is performed as step S11 by the transmission line 8a).

 [0039] Note that, unlike the present embodiment, if the outdoor unit 2 is not prefilled with refrigerant, the constituent devices are stopped abnormally when performing the above-described refrigerant amount determination operation prior to the processing of step S11. It is necessary to charge the refrigerant until the amount of refrigerant is low enough

(Step S12: Calculation of refrigerant quantity)

 Next, additional refrigerant charging is performed in the refrigerant circuit 10 while performing the above-described refrigerant amount determination operation. At this time, the additional charging of the refrigerant in step S12 is performed by the control unit 8 functioning as the refrigerant amount calculating means. The refrigerant amount in the refrigerant circuit 10 is calculated from the refrigerant flowing through the refrigerant circuit 10 at the time or the operating state quantity of the component equipment.

First, the refrigerant quantity calculation means in this embodiment will be described. The refrigerant quantity calculating means calculates the refrigerant quantity in the refrigerant circuit 10 by dividing the refrigerant circuit 10 into a plurality of parts and calculating the refrigerant quantity for each of the divided parts. More specifically, for each of the divided parts, a relational expression between the refrigerant amount of each part and the operating state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device is set. Use the amount of refrigerant in each part Can be calculated. And in this embodiment, a refrigerant circuit

10 shows a state in which the four-way switching valve 22 is shown by a solid line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the gas side of the outdoor heat exchanger 23, and the suction side of the compressor 21 is closed to the gas side. In the state where it is connected to the outlet of the indoor heat exchanger 42 via the valve 27 and the gas refrigerant communication pipe 7, the compressor 21 and the four-way switching valve 22 from the compressor 21 (not shown in FIG. 5) Of the outdoor heat exchanger 23 (hereinafter referred to as the high pressure gas pipe section E), the outdoor heat exchanger 23 section (that is, the condenser section A), and the liquid refrigerant circulation section B. The portion from the exchanger 23 to the subcooler 25 and the portion on the main refrigerant circuit side of the subcooler 25 (hereinafter referred to as the high temperature side liquid pipe section B1) and the liquid refrigerant circulation section B The part on the outlet side of the main refrigerant circuit side of the cooler 25 and the part from the supercooler 25 to the liquid side shut-off valve 26 (not shown in FIG. 5) (hereinafter referred to as the low temperature side liquid pipe) B2), the liquid refrigerant communication pipe 6 in the liquid refrigerant circulation section B (hereinafter referred to as the liquid refrigerant communication pipe section B3), and the liquid refrigerant communication pipe B in the liquid refrigerant communication section B from the liquid refrigerant communication pipe 6 A portion of the gas refrigerant circulation section D including the valve 41 and the indoor heat exchanger 42 (that is, the evaporator section C) up to the gas refrigerant communication pipe 7 (hereinafter referred to as an indoor unit section F), and a gas refrigerant Four-way switching from the part of the gas refrigerant communication pipe 7 in the circulation part D (hereinafter referred to as gas refrigerant communication pipe part G) and the gas side closing valve 27 (not shown in FIG. 5) of the gas refrigerant circulation part D The part up to the compressor 21 including the valve 22 and the accumulator 24 (hereinafter referred to as the low pressure gas pipe part H) and the liquid refrigerant circulation part B from the high temperature side liquid pipe part B1 to the bypass expansion valve 62 and the supercooler 25 Part up to the low pressure gas pipe part H including the part on the bypass refrigerant circuit side (hereinafter referred to as the nopass circuit part I) The relational expression is set for each part. Next, the relational expressions set for each part will be described.

 In the present embodiment, the relational expression between the refrigerant amount Mogl in the high-pressure gas pipe E and the operating state quantity of the refrigerant or the component device flowing through the refrigerant circuit 10 is, for example,

 Mogl = Vogl X p d

This is expressed as a functional expression obtained by multiplying the volume Vogl of the high-pressure gas pipe E of the outdoor unit 2 by the refrigerant density / 0 d in the high-pressure gas pipe E. Note that the volume Vogl of the high-pressure gas pipe E is a known value of the front force at which the outdoor unit 2 is installed at the installation location, and is stored in advance in the memory of the control unit 8. In addition, the density of the refrigerant in the high-pressure gas pipe E is the discharge temperature Td and It is obtained by converting the discharge pressure Pd.

 The relational expression between the refrigerant quantity Mc in the condenser part A and the operating state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device is, for example,

 Mc = kclXTa + kc2XTc + kc3XSHm + kc4XWc

The outdoor temperature Ta, the condensation temperature Tc, the compressor discharge superheat SHm, the refrigerant circulation rate Wc, the saturated liquid density pc of the refrigerant in the outdoor heat exchanger 23, and the refrigerant density P at the outlet of the outdoor heat exchanger 23 It is expressed as a function expression of co. The parameters kcl to kc7 in the above relational expression are obtained by regression analysis of the results of tests and detailed simulations, and are stored in the memory of the control unit 8 in advance. The compressor discharge superheat degree S Hm is the refrigerant superheat degree on the discharge side of the compressor. The discharge pressure Pd is converted to the refrigerant saturation temperature value, and the discharge temperature Td force is subtracted from the refrigerant saturation temperature value. Can be obtained. The refrigerant circulation amount Wc is expressed as a function of the evaporation temperature Te and the condensation temperature Tc (that is, Wc = f (Te, Tc)). The saturated liquid density pc of the refrigerant is obtained by converting the condensation temperature Tc. The refrigerant density p co at the outlet of the outdoor heat exchanger 23 is obtained by converting the condensation pressure Pc obtained by converting the condensation temperature Tc and the refrigerant temperature Tco.

 The relational expression between the refrigerant amount Moll in the high temperature side liquid pipe part B1 and the operating state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device is, for example,

 Moll = VollX p co

t, u, the volume Voll of the high-temperature side liquid pipe part B1 of the outdoor unit 2 was multiplied by the refrigerant density p co in the high-temperature side liquid pipe part B1 (that is, the refrigerant density at the outlet of the above-mentioned outdoor heat exchanger 23). Expressed as a function expression. The volume Voll of the high-pressure side liquid pipe section B1 is a known value of the front force at which the outdoor unit 2 is installed at the installation location, and is stored in the memory of the control section 8 in advance.

 The relational expression between the refrigerant quantity Mol2 in the low temperature side liquid pipe part B2 and the operating state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device is, for example,

Mol2 = Vol2X ip t is expressed as a functional expression obtained by multiplying the volume Vol2 of the low temperature side liquid pipe portion B2 of the outdoor unit 2 by the refrigerant density p lp in the low temperature side liquid pipe portion B2. Note that the volume Vol2 of the low temperature side liquid pipe section B2 is also a known value of the front force at which the outdoor unit 2 is installed at the installation location, and is stored in advance in the memory of the control section 8. Further, the refrigerant density p lp in the low temperature side liquid pipe section B2 is the refrigerant density at the outlet of the supercooler 25, and the condensation pressure Pc and the refrigerant temperature Tip at the outlet of the supercooler 25 are converted. Obtained by.

[0042] The relational expression between the refrigerant amount Mlp in the liquid refrigerant communication pipe section B3 and the operating state quantity of the refrigerant or the component device flowing through the refrigerant circuit 10 is, for example,

 Mlp = Vlp X ip

 This is expressed as a function equation obtained by multiplying the volume Vlp of the liquid refrigerant communication pipe 6 by the refrigerant density lp (that is, the refrigerant density at the outlet of the subcooler 25) in the liquid refrigerant communication pipe section B3.

 The relational expression between the refrigerant quantity Mr in the indoor unit F and the operating state quantity of the refrigerant or component equipment flowing through the refrigerant circuit 10 is, for example,

 Mr = krl XTlp + kr2 X AT + kr3 X SHr + kr4 XWr + kr5

 The refrigerant temperature Tlp at the outlet of the supercooler 25, the temperature difference ΔΤ obtained by subtracting the evaporation temperature Te from the room temperature Tr, the superheat degree SHr of the refrigerant at the outlet of the indoor heat exchanger 42, and the air volume Wr of the indoor fan 43 Expressed as a function expression. The parameters krl to kr5 in the above relational expression are obtained by regression analysis of the results of tests and detailed simulations, and are stored in the memory of the control unit 8 in advance. Here, the relational expression of the refrigerant quantity Mr is set corresponding to each of the indoor units 4, and the total refrigerant quantity of the indoor unit part F is calculated. When the indoor unit 4 is different in model and capacity, relational expressions with different values of the meters krl to kr5 are used.

[0043] The relational expression between the refrigerant amount Mgp in the gas refrigerant communication pipe section G and the operating state quantity of the refrigerant or the component device flowing through the refrigerant circuit 10 is, for example,

 Mgp = Vgp X gp

This is expressed as a function expression obtained by multiplying the volume Vgp of the gas refrigerant communication pipe 7 by the refrigerant density p gp in the gas refrigerant communication pipe section H. In addition, the refrigerant refrigerant in the gas refrigerant pipe connection G The density p gp is an average value of the refrigerant density ps on the suction side of the compressor 21 and the refrigerant density p eo at the outlet of the indoor heat exchanger 42 (that is, the inlet of the gas refrigerant communication pipe 7). . The refrigerant density ps is obtained by converting the suction pressure Ps and the suction temperature Ts. The refrigerant density p eo is the conversion value of the evaporation temperature Te, the evaporation pressure Pe, and the outlet temperature Teo of the indoor heat exchanger 42. Is obtained by converting.

 The relational expression between the refrigerant amount Mog2 in the low-pressure gas pipe part H and the operating state quantity of the refrigerant or the component device flowing through the refrigerant circuit 10 is, for example,

 Mog2 = Vog2 X p s

This is expressed as a functional expression obtained by multiplying the volume Vog2 of the low-pressure gas pipe H in the outdoor unit 2 by the refrigerant density p s in the low-pressure gas pipe H. Note that the volume Vog2 of the low-pressure gas pipe H is a known value of the pre-force that is shipped to the installation location, and is stored in the memory of the controller 8 in advance.

 The relational expression between the refrigerant amount Mob in the no-pass circuit section I and the operation state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device is, for example,

 Mob = kobl X co + kob2 X ps + kob3 X Pe + kob4

The refrigerant density p co at the outlet of the outdoor heat exchanger 23, the refrigerant density p s at the outlet of the subcooler 25 on the bypass circuit side, and the evaporation pressure Pe are expressed as functional expressions. Note that the parameters kobl to kob3 in the above relational expression are obtained by regression analysis of the results of tests and detailed simulations, and are stored in the memory of the control unit 8 in advance. Further, the volume Mob of the bypass circuit part I may be smaller than the other parts, and may be calculated by a simpler relational expression. For example,

 Mob = Vob X e X kob5

This is expressed as a functional expression obtained by multiplying the volume Vob of the bypass circuit part I by the saturated liquid density pe and the correction coefficient kob in the bypass circuit side part of the subcooler 25. Incidentally, the volume Vob of the bypass circuit section I is also a known value of the front force at which the outdoor unit 2 is installed at the installation location, and is stored in the memory of the control section 8 in advance. The saturated liquid density pe in the portion of the subcooler 25 on the bypass circuit side can be obtained by converting the suction pressure Ps or the evaporation temperature Te. [0045] In the present embodiment, a single outdoor unit 2 is used. When a plurality of outdoor units are connected, the refrigerant amounts Mogl, Mc, Moll, Mol2, Mog2 and Mob related to the outdoor units are: A relational expression of the refrigerant amount of each part is set corresponding to each of the plurality of outdoor units, and the total refrigerant quantity of the outdoor unit is calculated by adding the refrigerant amount of each part of the plurality of outdoor units. It has become so. When multiple outdoor units with different models and capacities are connected, the relational expression for the refrigerant amount of each part with different parameter values is used.

 As described above, in the present embodiment, using the relational expression for each part of the refrigerant circuit 10, the refrigerant flowing through the refrigerant circuit 10 in the refrigerant quantity determination operation or the operating state quantity of the component device is calculated. By doing so, the refrigerant amount of the refrigerant circuit 10 can be calculated.

 [0046] Since this step S12 is repeated until a condition for determining whether the refrigerant amount is appropriate in step S13, which will be described later, is satisfied, until the additional charge of the refrigerant is started and the force is completed, the refrigerant is Using the relational expression for each part of circuit 10, the amount of refrigerant in each part is calculated. More specifically, the refrigerant amount Mo in the outdoor unit 2 and the refrigerant amount Mr in the indoor unit 4 (that is, the refrigerant communication pipes 6 and 7) necessary for determining the suitability of the refrigerant amount in step S 13 described later. The amount of refrigerant in each part of the refrigerant circuit 10 excluding is calculated. Here, the refrigerant amount Mo in the outdoor unit 2 is calculated by calculating the power of the refrigerant amounts Mogl, Mc, Moll, Mol2, Mog2, and Mob in each part in the outdoor unit 2 described above.

 In this way, the control unit 8 that functions as the refrigerant amount calculating means for calculating the refrigerant amount of each part of the refrigerant circuit 10 from the refrigerant flowing in the refrigerant circuit 10 or the operating state quantity of the component device in the refrigerant automatic charging operation, performs step S. 12 processes are performed.

[0047] (Step S 13: Determination of Appropriate Refrigerant Quantity)

As described above, when additional charging of the refrigerant into the refrigerant circuit 10 is started, the refrigerant amount in the refrigerant circuit 10 gradually increases. Here, when the volume of the refrigerant communication pipes 6 and 7 is unknown, the amount of refrigerant to be filled in the refrigerant circuit 10 after the additional charging of the refrigerant cannot be defined as the refrigerant amount of the refrigerant circuit 10 as a whole. . However, outdoor unit 2 and indoor unit 4 (I.e., the refrigerant circuit 10 excluding the refrigerant communication pipes 6 and 7), the optimum refrigerant quantity of the outdoor unit 2 in the normal operation mode can be known in advance through tests and detailed simulations. Is stored in advance in the memory of the control unit 8 as the charging target value Ms, and the operating state quantity force of the refrigerant or component equipment flowing in the refrigerant circuit 10 in the automatic refrigerant charging operation is also calculated using the above-described relational expression. Additional refrigerant charging may be performed until the refrigerant amount value obtained by adding the refrigerant amount Mo of the outdoor unit 2 and the refrigerant amount Mr of the indoor unit 4 reaches the target charging value Ms. That is, step S13 determines whether the value of the refrigerant amount obtained by adding the refrigerant amount Mo of the outdoor unit 2 and the refrigerant amount Mr of the indoor unit 4 in the automatic refrigerant charging operation reaches the charging target value Ms. In this way, the process determines whether or not the amount of the refrigerant charged in the refrigerant circuit 10 by the additional charging of the refrigerant is appropriate.

 [0048] Then, in step S13, the additional charging of the refrigerant in which the refrigerant amount value obtained by adding the refrigerant amount Mo of the outdoor unit 2 and the refrigerant amount Mr of the indoor unit 4 is smaller than the target charging value Ms is completed. If not, the process of step S13 is repeated until the filling target value Ms is reached. In addition, when the refrigerant amount value obtained by adding the refrigerant amount Mo of the outdoor unit 2 and the refrigerant amount Mr of the indoor unit 4 reaches the charging target value Ms, the additional charging of the refrigerant is completed, and the automatic refrigerant charging is performed. Step S1 as the operation process is completed.

 In the refrigerant amount determination operation described above, as the additional charging of the refrigerant into the refrigerant circuit 10 progresses, the degree of supercooling SCo mainly at the outlet of the outdoor heat exchanger 23 tends to increase, resulting in outdoor heat exchange. Since the refrigerant amount Mc in the chamber 23 increases and the refrigerant amount in the other parts tends to be kept almost constant, the refrigerant target amount of the outdoor unit 2 is less than the outdoor unit 2 and the indoor unit 4. It may be set as a value corresponding only to Mo, or set as a value corresponding to the refrigerant amount Mc of the outdoor heat exchanger 23, and additional charging of the refrigerant may be performed until the charging target value Ms is reached. .

 [0049] In this way, it functions as a refrigerant amount determination means for determining the suitability of the refrigerant amount in the refrigerant circuit 10 in the refrigerant amount determination operation of the automatic refrigerant charging operation (that is, whether or not the charging target value Ms has been reached). The control unit 8 performs the process of step S13.

 (Step S2: Pipe length judgment operation)

When the automatic refrigerant charging operation in step S1 is completed, the pipe length determination in step S2 Transition to driving. In the pipe length determination operation, the processing of step S21 to step S24 shown in FIG. Here, Fig. 6 is a flow chart of the pipe length judgment operation.

 (Step S21: Pipe length judgment operation)

 In step S21, to obtain the operation data necessary for calculating the pipe lengths of the refrigerant communication pipes 6 and 7, in order to obtain the pipe volume Vlp of the liquid refrigerant communication pipe 6 and the pipe volume Vgp of the gas refrigerant communication pipe 7 The pipe length judgment operation is performed. The pipe length determination operation is an operation in which the operation state quantity of the refrigerant flowing in the refrigerant circuit 10 is changed by changing the control state of the constituent devices. The pipe length determination operation in the present embodiment is performed as follows.

 First, in the same manner as the refrigerant amount determination operation in step S11 in the above-described automatic refrigerant charging operation.

Then, the first state, which is the state before changing the control state, is created by performing cooling operation, condensing pressure control, liquid pipe temperature control, superheat degree control and evaporation pressure control. That is, in the refrigerant circuit 10, the condensing pressure Pc, the liquid pipe temperature Tlp, the degree of superheat SHr, and the evaporation pressure Pe are kept constant.

Then, in this first state, the superheat control is canceled (the opening degree of the indoor expansion valve 41 at this time is set to the first opening degree OV1), and as shown in FIG. Change stepwise to a second opening OV2 smaller than OV1. Here, the state at the second opening OV2 is the second state. Thus, if the opening of the indoor expansion valve 41 is reduced from the first opening OV1 to the second opening OV2, the flow resistance in the indoor expansion valve 41 increases, so the indoor expansion valve 41 and the indoor heat exchanger 42 The flow rate of the refrigerant passing through will decrease. For this reason, the temperature of the refrigerant at the outlet of the indoor heat exchanger increases, and a response appears that the degree of superheat SHr at the outlet of the indoor heat exchanger 42 increases. This response is propagated to the suction side of the compressor 21 through the gas refrigerant communication pipe 7, the gas side closing valve 27, the four-way switching valve 22, and the accumulator 24. That is, by performing an operation to reduce the opening of the indoor expansion valve 41 from the first opening OV 1 to the second opening OV2, the degree of superheat of the refrigerant on the suction side of the compressor 21 (hereinafter referred to as compressor intake) The superheat degree SHi) becomes a response similar to the superheat degree SHr at the outlet of the indoor heat exchanger 42. Specifically, Figure 7 (b ) As shown in (c), after the operation to reduce the opening of the indoor expansion valve 41 from the first opening OV1 to the second opening OV2, the inside of the indoor heat exchanger 42, the gas refrigerant communication pipe 7 After the passage of propagation time in the gas side shut-off valve 27, four-way selector valve 22 and accumulator 24 (hereinafter referred to as propagation time), this response (ie, from superheat SHil Response that changes to superheat SHi 2) appears. Here, the compressor suction superheat degree SHi is obtained by converting the suction pressure Ps of the compressor 21 into the saturation temperature value of the refrigerant and subtracting the saturation temperature value of the refrigerant from the suction temperature Ts. Since this propagation time becomes larger as the gas refrigerant communication pipe 7 is longer, for example, as shown in FIG. 7B, when the gas refrigerant communication pipe 7 is short, the propagation time τ is τ 1 When the gas refrigerant communication pipe 7 is long, the propagation time τ tends to be τ 2 longer than τ 1. Here, FIG. 7 is a graph showing changes over time in the opening degree of the indoor expansion valve 41 and the compressor intake superheat degree SHi in the pipe length determination operation.

 In the present embodiment, a response to increase the compressor suction superheat degree SHi appears by performing an operation to reduce the opening of the indoor expansion valve 41, but this is limited to this. In response to the operation of increasing the opening of the indoor expansion valve 41, a response to decrease the compressor superheating degree SHi may appear, and the control state of other constituent devices may be changed. First state force By changing to the second state, a response may appear as a change in compressor intake superheat SHi and other operating state quantities.

 The control described above is performed by the control unit 8 (more specifically, between the indoor side control unit 47, the outdoor side control unit 37, and the control units 37, 47 functioning as a pipe length determination operation control means for performing the pipe length determination operation. This is performed as a process of step S21 by the transmission line 8a) connecting the two.

 (Step S22: Propagation time detection)

Next, in step S22, the propagation time τ during the pipe length judgment operation in step S21 is detected. Here, as shown in FIG. 7, data of the change over time of the compressor intake superheat SHi from the time when the opening of the indoor expansion valve 41 is reduced from the first opening OV 1 to the second opening OV2 is shown. , And the propagation time τ is detected by measuring the time until the compressor suction superheat degree SHi increases and stabilizes again. That is, the propagation time τ is the amount of operation state that appears in the refrigerant flowing in the refrigerant circuit 10 by the pipe length determination operation described above. Change within a predetermined section in the refrigerant circuit 10 including at least the gas refrigerant communication pipe 7 (here, in the indoor heat exchanger 42, in the gas refrigerant communication pipe 7, in the gas side shut-off valve 27, and in the four-way switching valve) 2 corresponds to the time required for propagation in 2 and in accumulator 24).

[0052] The process for detecting the propagation time τ as described above is performed by the control unit 8 (more specifically, the indoor side control unit 47, the outdoor side control unit 37, and the control unit 37, which functions as a propagation time detection unit. This is performed as step S22 by the transmission line 8a) connecting 47.

 (Step S23: Calculation of the length of refrigerant communication pipe)

 Next, in step S23, the pipe lengths of the refrigerant communication pipes 6 and 7 are calculated based on the propagation time τ detected in step S22. As described above, there is a correlation between the propagation time and the pipe length of the gas refrigerant communication pipe 7 (hereinafter, the pipe length of the gas refrigerant communication pipe 7 is referred to as pipe length Lg) (Fig. 7). See), and the relational expression between pipe length Lg and propagation time is

 Lg = f (r)

 Can be expressed as This relational expression is obtained as a result of a test or the like performed in advance, and is stored in the memory of the control unit 8 in advance.

Here, since the relational expression of the pipe length L depends on the combination of the indoor unit and the outdoor unit as shown in FIG. 8, the relational expression between the pipe length Lg and the propagation time is Prepared by pre-stored in the memory of the outdoor control unit 37 that constitutes the control unit 8 in a form that is grouped for each model of the unit, and is selected according to the model information of the indoor unit 4 It is set by. For example, if the model information acquired from the indoor unit 4 via the control unit 8 force transmission line 8a that functions as an information acquisition means is `` α '', the relational expression for the pipe length L is Lg = fa (τ) Will be selected. Fig. 8 is a table showing comparison data of indoor unit models, relational expressions between pipe length and propagation time, pipe diameter of gas refrigerant pipe, and pipe diameter of liquid refrigerant pipe. It is.

 Then, the pipe length Lg of the gas refrigerant communication pipe 7 is calculated from the relational expression between the pipe length Lg and the propagation time selected for the model information power of the indoor unit 4 and the propagation time detected in step S22. .

[0054] Further, since the pipe length L1 of the liquid refrigerant communication pipe 6 can be regarded as substantially the same as the pipe length Lg of the gas refrigerant communication pipe 7, in this embodiment, the pipe length L1 of the liquid refrigerant communication pipe 6 Is Ll = Lg

Can be expressed as The pipe length L1 of the liquid refrigerant communication pipe 6 is calculated from this relational expression.

 Using the above relational expression, the pipe length Lg of the gas refrigerant communication pipe 7 and the pipe length L1 of the liquid refrigerant communication pipe 6 can be calculated from the propagation time.

 In this way, the process of step S23 is performed by the control unit 8 functioning as the pipe length calculating means for calculating the pipe lengths Lg and L1 of the refrigerant communication pipes 6 and 7 based on the propagation time.

 (Step S24: Calculation of refrigerant volume of refrigerant communication pipe)

 Next, in step S24, the volumes Vgp and Vlp of the refrigerant communication pipes 6 and 7 are calculated from the pipe lengths Lg and L1 of the refrigerant communication pipes 6 and 7 calculated in step S23. In order to calculate the volumes Vgp and Vlp, data for obtaining the cross-sectional area of the refrigerant communication pipes 6 and 7 such as the pipe diameter of the gas refrigerant communication pipe 7 and the pipe diameter of the liquid refrigerant communication pipe 6 is required. It is. Therefore, in this embodiment, as in the relational expression between the pipe length Lg and the propagation time described above, as shown in FIG. 8, the pipe diameter dg and the indoor unit of the gas refrigerant pipe connected to the indoor unit are shown. The pipe diameter dl of the gas refrigerant pipe connected to the indoor unit is prepared by being stored in advance in the memory of the outdoor control unit 37 constituting the control unit 8 in a form that is grouped for each indoor unit model. It is set by being selected according to the model information of the indoor unit 4. For example, when the model information acquired from the indoor unit 4 by the control unit 8 functioning as the information acquisition means is “a” via the transmission line 8a, dg a is set as the pipe diameter dg of the gas refrigerant pipe. Select dl a as the pipe diameter dl of the liquid refrigerant pipe.

 Then, as in this embodiment, when one indoor unit 4 is connected to the outdoor unit 2, the pipe diameter dg of the gas refrigerant pipe is set to the pipe diameter of the gas refrigerant communication pipe 7, and the liquid refrigerant Since the pipe diameter of the pipe dl can be the pipe diameter of the liquid refrigerant communication pipe 6, the pipe volume Vgp of the gas refrigerant connection pipe 7

 Vgp = Z4 X dg X dg X Lg

It can also be expressed as the pipe volume Vlp of the liquid refrigerant communication pipe 6

Vlp = 7u / 4 X dl X dl X Ll Can be expressed as The pipe volumes Vgp and Vlp are calculated from these relational expressions.

 Using the above relationship, pipe length Lg of gas refrigerant communication pipe 7 and liquid refrigerant communication pipe 6 pipe length L1 to gas refrigerant communication pipe 7 pipe volume Vgp and liquid refrigerant communication pipe 6 V lp It can be calculated.

[0056] In this way, the control unit 8 functioning as the pipe length calculation means performs a calculation based on the pipe diameters dg and dl from which the model information of the indoor unit 4 is obtained and the pipe lengths Lg and L1 obtained in step S23. It also has a function to calculate the pipe volume Vgp of the refrigerant refrigerant pipe 7 and Vlp of the liquid refrigerant pipe 6.

 (Step S3: Initial refrigerant quantity detection operation)

 When the pipe length determination operation in step S2 is completed, the process proceeds to the initial refrigerant amount determination operation in step S3. In the initial refrigerant quantity detection operation, the control unit 8 performs the processes of step S31 and step S32 shown in FIG. Here, FIG. 9 is a flowchart of the initial refrigerant quantity detection operation.

 (Step S31: Refrigerant amount judgment operation)

 In step S31, similar to the refrigerant amount determination operation in step S11 of the above-described automatic refrigerant charging operation, the refrigerant amount determination operation including the cooling operation, the condensation pressure control, the liquid pipe temperature control, the superheat degree control, and the evaporation pressure control is performed. . Here, the liquid pipe temperature target value Tlps in the liquid pipe temperature control, the superheat degree target value SHrs in the superheat degree control, and the low pressure target value Pes in the evaporation pressure control are, in principle, the refrigerant amount judgment operation in step S11 of the automatic refrigerant charging operation. The same value as the target value in is used.

[0057] In this way, the control unit 8 that functions as the refrigerant amount determination operation control unit that performs the refrigerant amount determination operation including the cooling operation, the condensing pressure control, the liquid pipe temperature control, the superheat degree control, and the evaporation pressure control, performs step S31. Is performed.

 (Step S32: Calculation of refrigerant amount)

Next, the control unit 8 that functions as the refrigerant amount calculation means while performing the refrigerant amount determination operation described above, the refrigerant flowing from the refrigerant circuit 10 in the initial refrigerant amount determination operation in step S32 or the operation state amount of the component device is used. Calculate the amount of refrigerant in circuit 10. Refrigerant times The refrigerant amount in the passage 10 is calculated by using a relational expression between the refrigerant amount of each part of the refrigerant circuit 10 and the operation state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device. Since the volume Vlp and Vgp of the refrigerant communication pipes 6 and 7 that were unknown after the installation of the components of the air conditioner 1 were calculated by the above-described pipe volume determination operation, the refrigerant communication was established. By multiplying the volume of the pipes 6 and 7 by the refrigerant density, calculate the refrigerant amounts Mlp and Mgp in the refrigerant communication pipes 6 and 7, and then add the refrigerant quantities in the other parts. Thus, the initial refrigerant amount of the entire refrigerant circuit 10 can be detected. This initial refrigerant quantity is used as a reference refrigerant quantity Mi for the refrigerant circuit 10 as a reference for determining the presence or absence of leakage from the refrigerant circuit 10 in the refrigerant leakage detection operation described later. Is stored in the memory of the control unit 8 as state quantity storage means. In this way, the control unit 8 that functions as a refrigerant amount calculating means that calculates the refrigerant amount in each part of the refrigerant circuit 10 from the refrigerant flowing in the refrigerant circuit 10 in the initial refrigerant amount detection operation or the operation state quantity of the constituent devices. Then, the process of step S32 is performed.

 <Refrigerant leak detection operation mode>

 Next, the refrigerant leak detection operation mode will be described with reference to FIGS. 1, 2, 5, and 10. FIG. Here, FIG. 10 is a flowchart of the refrigerant leak detection operation mode.

 In the present embodiment, it is detected periodically (for example, when it is not necessary to perform air conditioning during holidays, late at night, etc.) whether refrigerant has leaked from the refrigerant circuit 10 due to unforeseen causes. A case will be described as an example.

 (Step S41: Refrigerant amount judgment operation)

First, when a certain amount of time (for example, every six months to one year) has elapsed in the normal operation mode such as the cooling operation or the heating operation described above, the refrigerant leak detection operation mode is automatically or manually changed from the normal operation mode. In the same manner as the refrigerant quantity judgment operation in the initial refrigerant quantity detection operation, the refrigerant quantity judgment operation including the cooling operation, the condensing pressure control, the liquid pipe temperature control, the superheat degree control, and the evaporation pressure control is performed. Here, the liquid pipe temperature target value Tips in liquid pipe temperature control, the superheat degree target value SHrs in superheat degree control, and the low pressure target value Pes in evaporative pressure control are, in principle, the refrigerant quantity judgment operation in the initial refrigerant quantity detection operation. The same value as the target value in step S31 is used. [0059] The refrigerant amount determination operation is performed for each refrigerant leakage detection operation. For example, if the condensation pressure Pc is different, the refrigerant leakage occurs! Even if the refrigerant temperature Tco fluctuates at the outlet of the outdoor heat exchanger 23 due to the difference in temperature, the temperature of the refrigerant in the liquid refrigerant communication pipe 6 is the same as the liquid pipe temperature. Will be kept.

 As described above, the process of step S41 is performed by the control unit 8 functioning as the refrigerant amount determination operation control means for performing the refrigerant amount determination operation including the cooling operation, the condensation pressure control, the liquid pipe temperature control, the superheat degree control, and the evaporation pressure control. Done.

 (Step S42: Calculation of refrigerant quantity)

 Next, the control unit 8 that functions as the refrigerant quantity calculation means while performing the refrigerant quantity determination operation described above, the refrigerant from the operating state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device in the refrigerant leakage detection operation in step S42. Calculate the amount of refrigerant in circuit 10. The refrigerant amount in the refrigerant circuit 10 is calculated using a relational expression between the refrigerant amount of each part of the refrigerant circuit 10 and the operation state quantity of the refrigerant flowing through the refrigerant circuit 10 or the component device. At this time, the volumes Vlp and Vgp of the refrigerant communication pipes 6 and 7 that were unknown after the installation of the components of the air conditioner 1 are calculated by the above-described pipe volume determination operation as in the initial refrigerant amount determination operation. Therefore, the refrigerant volumes Mlp and Mgp in the refrigerant communication pipes 6 and 7 are calculated by multiplying the volumes Vlp and Vgp of the refrigerant communication pipes 6 and 7 by the density of the refrigerant. By adding the refrigerant amounts of the other parts, the refrigerant amount M of the entire refrigerant circuit 10 can be calculated.

[0060] Here, as described above, since the temperature T1 P of the refrigerant in the liquid refrigerant communication pipe 6 is kept constant at the same liquid pipe temperature target value Tips by the liquid pipe temperature control, the liquid refrigerant communication pipe section The refrigerant amount Mlp in B3 is kept constant even when the refrigerant temperature Tco fluctuates at the outlet of the outdoor heat exchanger 23, regardless of the operating conditions of the refrigerant leak detection operation.

In this way, the control unit 8 that functions as the refrigerant amount calculating means for calculating the refrigerant amount of each part of the refrigerant circuit 10 from the refrigerant flowing in the refrigerant circuit 10 or the operating state quantity of the component device in the refrigerant leakage detection operation causes the step S42. Is performed. (Steps S43, S44: Judgment of appropriateness of refrigerant amount, warning display)

 When the refrigerant leaks from the refrigerant circuit 10 to the outside, the amount of refrigerant in the refrigerant circuit 10 decreases. When the amount of refrigerant in the refrigerant circuit 10 decreases, the degree of supercooling SC at the outlet of the outdoor heat exchanger 23 tends to decrease, and accordingly, the amount of refrigerant Mc in the outdoor heat exchange decreases. However, the refrigerant amount in other parts tends to be kept almost constant. For this reason, the refrigerant amount M of the entire refrigerant circuit 10 calculated in step S42 described above is the reference refrigerant amount MU detected in the initial refrigerant amount detection operation when refrigerant leakage from the refrigerant circuit 10 occurs. If the refrigerant leaks from the refrigerant circuit 10 and becomes V, in this case, it becomes almost the same value as the reference refrigerant amount Mi.

Utilizing this fact, in step S43, it is determined whether or not refrigerant has leaked. If it is determined in step S43 that no refrigerant leaks from the refrigerant circuit 10, the refrigerant leak detection operation mode is terminated.

 On the other hand, if it is determined in step S43 that refrigerant has leaked from the refrigerant circuit 10, the process proceeds to step S44, and a warning is sent to the warning display unit 9 informing that the refrigerant has been detected. After the display, the refrigerant leak detection operation mode is terminated.

 In this way, the refrigerant amount determination means for detecting the presence or absence of refrigerant leakage by determining whether or not the refrigerant amount in the refrigerant circuit 10 is appropriate while performing the refrigerant amount determination operation in the refrigerant leakage detection operation mode. The processing of steps S42 to S44 is performed by the control unit 8 that functions as one refrigerant leakage detection means.

 [0062] As described above, in the air conditioner 1 of the present embodiment, the control unit 8 includes the refrigerant amount determination operation means, the refrigerant amount calculation means, the refrigerant amount determination means, the pipe length determination operation means, the pipe length calculation means, By functioning as information acquisition means and state quantity accumulation means, a refrigerant quantity determination system for determining the suitability of the refrigerant quantity charged in the refrigerant circuit 10 is configured.

 (3) Features of the air conditioner

 The air conditioner 1 of the present embodiment has the following features.

 (A)

In the air conditioner 1 of the present embodiment, the pipe length determination operation is performed to change the control state of the component device to the second state different from the first state force and the first state. The change in the operating state amount that appears in the refrigerant flowing in the refrigerant circuit 10 is within a predetermined section in the refrigerant circuit 10 including at least the gas refrigerant communication pipe 7 (in this case, in the indoor heat exchange 42, the gas refrigerant communication pipe 7), the propagation time τ required to propagate through the gas side shut-off valve 27, the four-way switching valve 22 and the accumulator 24) is detected, and based on this propagation time τ, the refrigerant communication pipes 6 and 7 Since the pipe length is calculated, for example, even if the pipe length of the gas refrigerant communication pipe 7 is unknown after installing the components, the pipe length Lg of the refrigerant communication pipe 7 can be known. . Thereby, the pipe lengths Lg and L1 of the refrigerant communication pipes 6 and 7 can be obtained while reducing the time for inputting the information of the refrigerant communication pipes 6 and 7.

 [0063] Then, in this air conditioner 1, the refrigerant communication pipe 6, after the propagation time detected in the pipe length determination operation using the relational expression between the propagation time and the pipe length Lg of the gas refrigerant communication pipe 7, Calculate the pipe lengths Lg and L1 of 7 and use the calculated pipe lengths Lg and L1 and the indoor unit 4 as the unit to be used. Since the volume Vgp and Vlp of the connecting pipes 6 and 7 are calculated, the piping volumes Vgp and Vlp of the refrigerant connecting pipes 6 and 7 are accurately determined while reducing the effort for inputting the information of the refrigerant connecting pipes 6 and 7. Can be calculated.

 In this air conditioner 1, the pipe lengths Lg and L1 of the refrigerant communication pipes 6 and 7 calculated by the control unit 8 functioning as pipe length calculation means, and the refrigerant or component equipment flowing through the refrigerant circuit 10 Since the amount of refrigerant in the refrigerant circuit 10 is determined using the operating state quantity, it is possible to determine the appropriateness of the refrigerant quantity in the refrigerant circuit while reducing the effort of inputting information on the refrigerant communication pipes 6 and 7. Can be determined with high accuracy.

 [0064] (B)

 In the air conditioner 1 of the present embodiment, in the pipe length determination operation, the opening OV of the indoor expansion valve 41 is changed from the first opening OV1 as the first state to the second opening OV2 as the second state. Therefore, the change in the operating state quantity appearing in the refrigerant flowing in the refrigerant circuit 10 can be made to appear rapidly and clearly, and the propagation time can be accurately detected.

Specifically, in this air conditioner 1, in the pipe length determination operation in which the opening OV of the indoor expansion valve 41 is changed, the pipe length is used as the operation state quantity for detecting the propagation time. Since the operation state quantity of the refrigerant flowing in the suction side of the compressor 21 in the judgment operation (here, the compressor intake superheat degree SHi) is used, the change force of this operation state quantity is a refrigerant including at least the gas refrigerant communication pipe 7 It propagates in a predetermined section in the circuit 10 (in this case, in the indoor heat exchanger 42, in the gas refrigerant communication pipe 7, in the gas side shut-off valve 27, in the four-way selector valve 22, and in the accumulator 24). It is possible to detect the propagation time required for this, and the pipe length Lg of the gas refrigerant communication pipe 7 can be obtained from this propagation time. Also, the compressor suction superheat degree SHi as the superheat degree of the refrigerant flowing on the suction side of the compressor 21 is used as the operating state quantity of the refrigerant flowing on the suction side of the compressor 21 used for detecting the propagation time τ. Therefore, the influence of the change in the opening degree of the indoor expansion valve 41 appears clearly, and the propagation time can be detected more accurately.

[0065] Further, in this air conditioner 1, although the pipe length determination operation is performed, the cooling operation, the condensing pressure control, the liquid pipe temperature control, and the evaporation pressure control are performed. Even when the opening degree OV of 41 is changed from the first opening degree OV1 to the second opening degree OV2, the inside of the refrigerant circuit 10 is maintained so that the condensation pressure Pc, the liquid pipe temperature Tip, and the evaporation pressure Pe are kept constant. Since the state of the flowing refrigerant is controlled, the temperature and pressure conditions of the refrigerant flowing into the indoor expansion valve 41 are stabilized, and the outlet force of the indoor expansion valve 41 is also reduced between the intake side of the compressor 21 and the refrigerant. The pressure condition will be stable. As a result, the influence of the change in the opening degree of the indoor expansion valve 41 becomes clear, and the propagation time can be detected more accurately.

 (C)

 In the air conditioner 1 of the present embodiment, the refrigerant circuit 10 is divided into a plurality of parts, and a relational expression between the refrigerant amount and the operating state quantity of each part is set. Compared to the simulation, the calculation load can be reduced, and the operating state quantity important for calculating the refrigerant amount in each part can be selectively captured as a variable in the relational expression. The calculation accuracy of the refrigerant amount is also improved, and as a result, the suitability of the refrigerant amount in the refrigerant circuit 10 can be determined with high accuracy.

[0066] For example, the control unit 8 serving as the refrigerant amount calculating means uses the relational expression to calculate the refrigerant flowing through the refrigerant circuit 10 or the operating state quantity force of the constituent device in the automatic refrigerant charging operation in which the refrigerant is filled into the refrigerant circuit 10. Also, the amount of refrigerant in each part can be calculated quickly. Moreover, the amount of refrigerant The control unit 8 serving as a determination unit uses the calculated refrigerant amount of each part to calculate the refrigerant amount in the refrigerant circuit 10 (specifically, the refrigerant amount Mo in the outdoor unit 2 and the refrigerant amount Mr in the indoor unit 4). It is possible to determine with high accuracy whether the force has reached the filling target value Ms.

 Further, the control unit 8 uses the relational expression to determine whether the refrigerant flowing through the refrigerant circuit 10 in the initial refrigerant amount detection operation in which the initial refrigerant amount is detected after the component device is installed or after the refrigerant circuit 10 is filled with the refrigerant or By calculating the refrigerant amount of each part from the operation state quantities of the component devices, the initial refrigerant amount as the reference refrigerant amount Mi can be quickly calculated. Also, the initial cooling amount can be detected with high accuracy.

[0067] Further, the control unit 8 uses the relational expression to determine whether the refrigerant flowing through the refrigerant circuit 10 in the refrigerant leakage detection operation for determining whether or not the refrigerant leaks from the refrigerant circuit 10 or the operating state quantity force of the constituent devices. The amount of refrigerant in the portion can be calculated quickly. The control unit 8 also increases the presence or absence of refrigerant leakage from the refrigerant circuit 10 by comparing the calculated refrigerant amount of each part with the reference refrigerant amount Mi that serves as a reference for determining the presence or absence of leakage. The accuracy can be determined.

 (D)

 In the air conditioner 1 of the present embodiment, the subcooler as a temperature adjustment mechanism capable of adjusting the temperature of the refrigerant sent from the outdoor heat exchanger 23 as a condenser to the indoor expansion valve 41 as an expansion mechanism. 25 is provided, and the capacity control of the subcooler 25 is performed so that the temperature Tip of the refrigerant sent from the subcooler 25 to the indoor expansion valve 41 as the expansion mechanism is constant during the refrigerant quantity determination operation. Therefore, the refrigerant density p lp in the refrigerant piping from the supercooler 25 to the indoor expansion valve 41 is not changed, so that the refrigerant temperature Tco at the outlet of the outdoor heat exchanger 23 as a condenser is the amount of refrigerant. Even if it is different for each judgment operation, the effect of the difference in refrigerant temperature is such that the outlet power of the outdoor heat exchanger ^^ 23 is contained only in the refrigerant pipe leading to the subcooler 25, and the refrigerant amount is judged. The refrigerant at the outlet of the outdoor heat exchanger Differences in degrees Tco (i.e., the difference in density of the refrigerant) can be reduced decision error due.

[0068] In particular, as in this embodiment, the outdoor unit 2 as a heat source unit and the indoor unit 4 as a utilization unit are connected via a liquid refrigerant communication pipe 6 and a gas refrigerant communication pipe 7. The refrigerant communication pipes 6 and 7 that connect between the outdoor unit 2 and the indoor unit 4 have different lengths depending on conditions such as the installation location. If the temperature increases, the difference in the refrigerant temperature Tco at the outlet of the outdoor heat exchanger 23 causes the outlet power of the outdoor heat exchanger to also constitute the majority of the refrigerant pipe that reaches the indoor expansion valve 41. As described above, the supercooler 25 is provided, and the refrigerant in the liquid refrigerant communication pipe 6 is used during the refrigerant amount judgment operation as described above. The capacity control of the supercooler 25 is controlled so that the temperature tip of the refrigerant is constant, so that the refrigerant density p lp in the refrigerant pipe from the supercooler 25 to the indoor expansion valve 41 does not change. Therefore, when determining the amount of refrigerant, the phase of the refrigerant temperature at the outlet Tco of the outdoor heat exchanger ^^ 23 The determination error due to the difference (that is, the difference in refrigerant density) can be reduced.

 [0069] For example, in the automatic refrigerant charging operation in which the refrigerant in the refrigerant circuit 10 is charged, it is possible to determine with high accuracy whether or not the amount of the refrigerant in the refrigerant circuit 10 has reached the target charging value Mi. In addition, the initial refrigerant amount can be detected with high accuracy in the initial refrigerant amount detection operation in which the initial refrigerant amount is detected after the component device is installed or after the refrigerant circuit 10 is filled with the refrigerant. In addition, in the refrigerant leak detection operation for determining whether or not the refrigerant leaks from the refrigerant circuit 10, it is possible to accurately determine whether or not the refrigerant leaks from the refrigerant circuit 10.

[Second Embodiment]

 In the air conditioner 1 of the first embodiment described above, an example in which the present invention is applied to an outdoor unit 2 as a heat source unit and one indoor unit 4 as a utilization unit connected thereto. As described above, as shown in FIGS. 11 and 12, the present invention is applied to the air conditioner 101 in which a plurality of (here, two) indoor units 4 and 5 are connected to the outdoor unit 2. May be. Here, FIG. 11 is a schematic configuration diagram of the air-conditioning apparatus 101 according to the second embodiment. FIG. 12 is a control block diagram of the air conditioner 101.

[0070] Specifically, the air conditioner 101 configures a vapor compression refrigerant circuit 110 by further connecting the indoor unit 5 having the same configuration as the indoor unit 4 of the first embodiment. Yes. In addition, about the structure of the indoor unit 5, it is the indoor side which the indoor unit 5 has. The refrigerant circuit is denoted by reference numeral 10b, and is denoted by reference numeral 50 in place of the reference numeral 40 indicating each part of the indoor unit 4, and description of each part is omitted. Further, the indoor side control unit 57 of the indoor unit 5 is connected to the indoor side control unit 47 of the indoor unit 4 and to the outdoor side control unit 37 of the outdoor unit 2 via a transmission line 108a. Can be exchanged. That is, the control unit 108 that controls the operation of the entire air conditioner 101 by the indoor side control unit 47, the indoor side control unit 57, the outdoor side control unit 37, and the transmission line 108a that connects the control units 37, 47, and 57. Is configured.

 [0071] Also in the air conditioner 101 having such a configuration, the same automatic refrigerant charging operation, initial refrigerant amount detection operation, pipe length determination operation, and refrigerant leakage detection operation as the air conditioner 1 of the first embodiment are performed. It can be carried out.

 However, in the air conditioner 101 of the present embodiment, since there are a plurality of indoor units (that is, the indoor units 4 and 5), for example, under the condition that both the indoor units 4 and 5 are operated, When the pipe length determination operation (operation to change the opening OV of the indoor expansion valve) in the first embodiment is performed simultaneously on both the indoor unit 4 and the indoor unit 5, the operation state quantity from the indoor unit 4 side is reduced. The change propagates to the suction side of the compressor 21 in a state in which the change of the operation state quantity of the indoor unit 5 side force is mixed. Then, the change in the operation state quantity on the indoor unit 4 side becomes a disturbance for the change in the operation state quantity on the indoor unit 4 side, and the operation condition on the indoor unit 4 side for the change in the operation state quantity on the indoor unit 5 side. Since the change in quantity becomes a disturbance, there is a possibility that the propagation time cannot be accurately detected.

 [0072] Therefore, in the case where a plurality of indoor units are connected to the outdoor unit as in the air conditioner 101 of the present embodiment, the pipe length determination operation is performed only for one of the plurality of indoor units. By doing so, it is desirable that there be no disturbance on the other indoor unit side.

Therefore, in the air conditioner 101 of the present embodiment, when calculating the pipe lengths Lg and L1 of the refrigerant communication pipes 6 and 7, the control unit 108 as a pipe length determination operation control means includes the indoor units 4 and 5 The pipe length judgment operation is performed for one of them (for example, indoor unit 4) so that there is no disturbance on the other indoor unit (in this case, outdoor unit 5) side, and the propagation time τ is accurately set. So that it can be detected. [Other embodiments]

 As mentioned above, although embodiment of this invention was described based on drawing, specific structure can be changed in the range which does not deviate from the summary of this invention which is not restricted to these embodiment.

 For example, in the above-described embodiment, an example in which the present invention is applied to an air conditioner capable of switching between cooling and heating has been described. However, the present invention is not limited to this, and other air conditioners such as a cooling-only air conditioner. The present invention may be applied to. In the above-described embodiment, the example in which the present invention is applied to the air conditioner including one outdoor unit has been described. However, the present invention is not limited to this, and the air conditioner includes a plurality of outdoor units. The present invention may be applied to an apparatus.

 Industrial applicability

[0074] If the present invention is used, the suitability of the amount of refrigerant in the refrigerant circuit can be determined with high accuracy while reducing the effort of inputting information of the refrigerant communication pipe before the operation of the separate type air conditioner. Become.

Claims

The scope of the claims

 [1] Refrigerant circuit (10, 110) configured by connecting heat source unit (2) and utilization unit (4, 5) via refrigerant communication pipe (6, 7);

 An operation control means capable of performing a pipe length determination operation for changing the control state of the component device to a second state different from the first state force and the first state;

 Based on the propagation time required for the change in the operating state quantity appearing in the refrigerant flowing in the refrigerant circuit by the pipe length judgment operation to propagate through at least a predetermined section of the refrigerant circuit including the refrigerant communication pipe! A pipe length calculating means for calculating the pipe length of the refrigerant communication pipe;

 Air conditioner (1, 101) equipped with.

[2] The refrigerant circuit (10, 110) includes a compressor (21), a condenser (23), an expansion valve (41, 51), and an evaporator (42, 52).

 The said operation control means changes the opening degree of the said expansion valve into the 2nd opening degree as the 2nd opening degree as said 1st opening force as said 1st state in the said pipe length determination driving | operation. Air conditioner (1, 101).

[3] The refrigerant communication pipe has a liquid refrigerant communication pipe (6) and a gas refrigerant communication pipe (7).

 The heat source unit (2) includes the compressor (21) and a heat source side heat exchanger (23) capable of functioning as the condenser,

 The utilization unit (4, 5) includes the expansion valve (41, 51) and a utilization side heat exchange (42, 52) capable of functioning as the evaporator,

 The refrigerant circuit (10, 110) includes the compressor (21), the heat source side heat exchanger (23), the liquid refrigerant communication pipe (6), the expansion valve (41, 51), and the The use side heat exchanger (42, 52) is connected to the gas refrigerant communication pipe (7), and the propagation time is determined by the compressor in the pipe length determination operation (21). Detected from the change in the operating state quantity of the refrigerant flowing on the suction side of

 The air conditioner (1, 101) according to claim 2.

[4] Operation of refrigerant flowing on the suction side of the compressor (21) used for detection of the propagation time The air conditioner (1) according to claim 3, wherein the state quantity is a degree of superheat of the refrigerant flowing on the suction side of the compressor.

 [5] A plurality of the utilization units (4, 5) are connected to the heat source unit (2), and the operation control means performs the pipe length determination operation for one of the plurality of utilization units. I do,

 The air conditioner (101) according to any one of claims 1 to 4.

 [6] The pipe length calculating means calculates the pipe length of the refrigerant communication pipe from the relational expression between the propagation time and the pipe length of the refrigerant communication pipe (6, 7), and the refrigerant circuit (10, 110) The volume of the refrigerant communication pipe is calculated from the pipe diameter of the refrigerant communication pipe obtained from the information of the utilization units (4, 5) constituting the pipe and the pipe length of the refrigerant communication pipe calculated using the relational expression. The air conditioner (1, 101) according to any one of claims 1 to 5.

 [7] Using the pipe length of the refrigerant communication pipe (6, 7) calculated by the pipe length calculation means and the operating state quantity of the refrigerant or the component device flowing through the refrigerant circuit (10, 110), The air conditioner (1, 101) according to any one of claims 1 to 6, further comprising a refrigerant amount determination means for determining whether or not the refrigerant amount in the refrigerant circuit is appropriate.