Refrigeration cycle device

Abstract

A refrigeration cycle device of an embodiment has an indoor unit, first and second outdoor units, and a control portion. The indoor unit has an indoor heat exchanger. The first and second outdoor units are connected in parallel to the indoor unit. The second outdoor unit has a compressor, an outdoor heat exchanger, and a four-way valve. The four-way valve switches a supply destination of refrigerant discharged from the compressor between the indoor heat exchanger and the outdoor heat exchanger. The four-way valve includes a main valve having a main valve body and a sub valve having a sub valve body. The main valve body is movable between a first position and a second position. The first position is a position at which the refrigerant discharged from the compressor is supplied to one of the indoor heat exchanger and the outdoor heat exchanger. The second position is a position at which the refrigerant discharged from the compressor is supplied to the other of the indoor heat exchanger and the outdoor heat exchanger. The sub valve body is driven by a solenoid and is movable between a third position and a fourth position. The third position is a position at which the main valve body is disposed in the first position. The fourth position is a position at which the main valve body is disposed in the second position. In a case where the first outdoor unit is operating and the second outdoor unit is stopped, when the main valve body is not in the first position, the control portion disposes the sub valve body in the fourth position and then moves the sub valve body to the third position.

Description

Technical Field

[0001] Embodiments of the present invention relate to a refrigeration cycle device. Background Technology

[0002] The refrigeration cycle unit of a multi-air conditioning system includes: an indoor unit with an indoor heat exchanger; and multiple outdoor units connected in parallel with the indoor unit. Each outdoor unit includes a compressor, an outdoor heat exchanger, and a four-way valve. The four-way valve switches the refrigerant discharged from the compressor between the indoor and outdoor heat exchangers.

[0003] In a multi-unit outdoor unit setup, sometimes only a portion of the units operate while the rest are shut down. In the shut-down units, a malfunctioning four-way valve may occur. This malfunction needs to be addressed by eliminating the malfunctioning four-way valve in the shut-down units. Existing technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2002-340386 Summary of the Invention The technical problem that the invention aims to solve

[0005] The technical problem to be solved by the present invention is to provide a refrigeration cycle device that can eliminate the switching malfunction of the four-way valve in the stopped outdoor unit. Technical means for solving technical problems

[0006] The refrigeration cycle device of the embodiment includes: an indoor unit; a first outdoor unit and a second outdoor unit; and a control unit. The indoor unit has an indoor heat exchanger. The first and second outdoor units are connected in parallel with the indoor unit. The second outdoor unit has a compressor, an outdoor heat exchanger, and a four-way valve. The four-way valve switches the supply destination of refrigerant discharged from the compressor between the indoor and outdoor heat exchangers. The four-way valve has: a main valve having a main valve body; and a secondary valve having a secondary valve body. The main valve body is movable between a first position and a second position. The first position is the position where refrigerant discharged from the compressor is supplied to one of the indoor and outdoor heat exchangers. The second position is the position where refrigerant discharged from the compressor is supplied to the other of the indoor and outdoor heat exchangers. The secondary valve body is driven by a solenoid and is movable between a third position and a fourth position. The third position is the position where the main valve body is positioned in the first position. The fourth position is the position where the main valve body is positioned in the second position. When the first outdoor unit is operating and the second outdoor unit is stopped, if the main valve body is not in the first position, the control unit will configure the auxiliary valve body in the fourth position and then move the auxiliary valve body to the third position. Attached Figure Description

[0007] Figure 1 This is a simplified structural diagram and a diagram illustrating the first operation of the refrigeration cycle device according to the embodiment. Figure 2 This is a simplified structural diagram and a diagram illustrating the first action of a four-way valve. Figure 3 This is a diagram illustrating the second action of a four-way valve. Figure 4 This is a diagram illustrating the second operation of the refrigeration cycle device. Figure 5 This is a diagram illustrating the third action of a four-way valve. Figure 6 This is a diagram illustrating the fourth action of a four-way valve. Figure 7 It is a graph showing the relationship between the compressor's suction pressure and the switching time of the four-way valve. Detailed Implementation

[0008] Hereinafter, the refrigeration cycle apparatus of the embodiment will be described with reference to the accompanying drawings. Figure 1 This is a simplified structural diagram and a first operational illustration of the refrigeration cycle device according to the embodiment. The refrigeration cycle device 1 has multiple indoor units 10, multiple outdoor units 11, 12, and refrigerant flow paths through which refrigerant flows. The refrigeration cycle device 1 contains refrigerants such as R410A, R32, R454B, R466A, or carbon dioxide (CO2). The refrigerant circulates within the refrigeration cycle device 1 during a phase change.

[0009] Multiple indoor units 10 are connected in parallel with multiple outdoor units 11 and 12. The indoor unit 10 has an indoor heat exchanger 4 and an indoor expansion valve 6a. Multiple outdoor units 11 and 12 are connected in parallel with multiple indoor units 10. Each outdoor unit 11 and 12 has a first outdoor unit 11 and a second outdoor unit 12. Multiple outdoor units 11 and 12 may also have three or more outdoor units. The first outdoor unit 11 has a compressor 2, a four-way valve 18, an outdoor heat exchanger 8, and an outdoor expansion valve 6b. The second outdoor unit 12 is constructed in the same manner as the first outdoor unit 11. Hereinafter, the compressor 2 of the first outdoor unit 11 is sometimes referred to as the first compressor 2, and the compressor 2 of the second outdoor unit 12 is sometimes referred to as the second compressor 2. Additionally, the four-way valve 18 of the first outdoor unit 11 is sometimes referred to as the first four-way valve 18, and the four-way valve 18 of the second outdoor unit 12 is sometimes referred to as the second four-way valve 18.

[0010] The four-way valve 18 switches the refrigerant discharged from the compressor 2 between the indoor heat exchanger 4 and the outdoor heat exchanger 8. When the refrigeration cycle unit 1 is in indoor heating operation, the refrigerant discharged from the compressor 2 is supplied to the indoor heat exchanger 4. When the refrigeration cycle unit 1 is in indoor cooling operation or defrosting operation of the outdoor heat exchanger 8, the refrigerant discharged from the compressor 2 is supplied to the outdoor heat exchanger 8. Figure 1 In the example, the four-way valve 18 is switched to enable the refrigeration cycle unit 1 to operate in heating mode.

[0011] The operation of the refrigeration cycle unit 1 in heating mode will be explained. Compressor 2 compresses the low-pressure gaseous refrigerant (fluid) inside, transforming it into a high-temperature, high-pressure gaseous refrigerant. The refrigerant discharged from compressor 2 is supplied to four-way valve 18 via oil separator 2b and check valve 3. When the refrigeration cycle unit 1 is operating in heating mode, refrigerant is supplied from four-way valve 18 to indoor heat exchanger 4 of indoor unit 10. The indoor heat exchanger 4 functions as a condenser (radiator). The condenser dissipates heat by converting the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 2 into a high-pressure liquid refrigerant. The refrigerant discharged from the indoor heat exchanger 4 flows through the indoor expansion valve 6a and the outdoor expansion valve 6b.

[0012] The indoor expansion valve 6a and the outdoor expansion valve 6b reduce the pressure of the high-pressure liquid refrigerant supplied from the indoor heat exchanger 4, transforming the high-pressure liquid refrigerant into a low-temperature, low-pressure gas-liquid two-phase refrigerant. The refrigerant discharged from the outdoor expansion valve 6b is supplied to the outdoor heat exchanger 8. The outdoor heat exchanger 8 functions as an evaporator (heat absorber). The evaporator converts the two-phase refrigerant discharged from the outdoor expansion valve 6b into a low-pressure gaseous refrigerant. The refrigerant discharged from the outdoor heat exchanger 8 is supplied to the four-way valve 18. The refrigerant discharged from the four-way valve 18 is then supplied to the compressor 2 via the storage tank (gas-liquid separator) 2a.

[0013] When the refrigeration cycle unit 1 is in refrigeration or defrosting operation, from Figure 1 The four-way valve 18 is switched on and off. In this case, the refrigerant discharged from the compressor 2 flows sequentially through the four-way valve 18, outdoor heat exchanger 8, outdoor expansion valve 6b, indoor expansion valve 6a, indoor heat exchanger 4, four-way valve 18, and compressor 2. In this case, the outdoor heat exchanger 8 functions as a condenser (radiator), and the indoor heat exchanger 4 functions as an evaporator (heat absorber).

[0014] The refrigeration cycle unit 1 includes a discharge pressure sensor 14, a suction pressure sensor 15, a suction temperature sensor 16, and an external gas temperature sensor 17. The discharge pressure sensor 14 is located in the refrigerant flow path between the discharge port of the compressor 2 and the four-way valve 18. The discharge pressure sensor 14 outputs a discharge pressure signal corresponding to the discharge pressure of the refrigerant in the compressor 2. The suction pressure sensor 15 and the suction temperature sensor 16 are located in the refrigerant flow path between the suction port of the compressor 2 and the four-way valve 18. The suction pressure sensor 15 outputs a suction pressure signal corresponding to the suction pressure of the refrigerant in the compressor 2. The suction temperature sensor 16 outputs a suction temperature signal corresponding to the temperature of the refrigerant drawn into the compressor 2. The external gas temperature sensor 17 is located in the outdoor unit where it comes into contact with external gas. The external gas temperature sensor 17 outputs an external gas temperature signal corresponding to the external gas temperature.

[0015] The refrigeration cycle unit 1 includes a CPU (Central Processing Unit), memory, and auxiliary storage devices. The CPU functions as the control unit 13 by executing programs stored in the memory and auxiliary storage devices. The control unit 13 controls the operation of each part of the refrigeration cycle unit 1. The control unit 13 receives discharge pressure signals, suction pressure signals, suction temperature signals, and external gas temperature signals. The control unit 13 controls the energization of the four-way valve 18 (described later) to the solenoid 31.

[0016] The structure of the four-way valve 18 will be described in detail. Figure 2 This is a simplified structural diagram and a diagram illustrating the first action of a four-way valve. Figure 3 This is a diagram illustrating the second action of a four-way valve. Figure 2 This refers to the state of the four-way valve 18 during heating operation. Figure 3 This indicates the state of the four-way valve 18 during refrigeration or defrosting operation. The four-way valve 18 has a main valve 20 and a secondary valve (pilot valve) 30.

[0017] The main valve 20 has a housing 29 and a main valve body 28. The housing 29 is formed in a cylindrical shape. The housing 29 has a first port 21, a second port 22, a third port 23, and a fourth port 24. The first port 21 is connected to the discharge port of the compressor 2. The second port 22 is connected to one of the indoor heat exchanger 4 and the outdoor heat exchanger 8. In this embodiment, the second port 22 is connected to the indoor heat exchanger 4. The third port 23 is connected to the other of the indoor heat exchanger 4 and the outdoor heat exchanger 8. In this embodiment, the third port 23 is connected to the outdoor heat exchanger 8. The fourth port 24 is connected to the suction port of the compressor 2. The connection destinations of each port represent the ports initially connected among the discharge port of the compressor 2, the suction port of the compressor 2, the indoor heat exchanger 4, and the outdoor heat exchanger 8. For example, the first port 21 is initially connected via... Figure 1 The check valve 3 and oil separator 2b shown are connected to the discharge port of compressor 2.

[0018] The main valve body 28 is located near the center along the long side of the housing 29. The main valve body 28 is movable between a first position P1 and a second position P2 along the long side of the housing 29.

[0019] exist Figure 2 In this embodiment, the main valve body 28 is positioned at a first position P1. At the first position P1, the main valve body 28 is connected to a first port 21 and a second port 22. At the first position P1, the main valve body 28 supplies refrigerant discharged from the compressor 2 to one of the indoor heat exchanger 4 and the outdoor heat exchanger 8. In this embodiment, the refrigerant discharged from the compressor 2 is supplied to the indoor heat exchanger 4 through the first port 21 and the second port 22. At the first position P1, the main valve body 28 is connected to a third port 23 and a fourth port 24. In this embodiment, the refrigerant discharged from the outdoor heat exchanger 8 is supplied to the suction port of the compressor 2 through the third port 23 and the fourth port 24.

[0020] exist Figure 3 In this embodiment, the main valve body 28 is positioned at the second position P2. At the second position P2, the main valve body 28 is connected to the first port 21 and the third port 23. At the second position P2, the main valve body 28 supplies refrigerant discharged from the compressor 2 to one of the indoor heat exchanger 4 and the outdoor heat exchanger 8. In this embodiment, the refrigerant discharged from the compressor 2 is supplied to the indoor heat exchanger 8 through the first port 21 and the third port 23. At the second position P2, the main valve body 28 is connected to the second port 22 and the fourth port 24. In this embodiment, the refrigerant discharged from the indoor heat exchanger 4 is supplied to the suction port of the compressor 2 through the second port 22 and the fourth port 24.

[0021] The main valve 20 has a first cylinder chamber 26 and a second cylinder chamber 27. The first cylinder chamber 26 is formed between one end of the housing 29 in the long side direction and a first piston 26p disposed on one side of the main valve body 28. The second cylinder chamber 27 is formed between the other end of the housing 29 in the long side direction and a second piston 27p disposed on the other side of the main valve body 28. The first piston 26p and the second piston 27p are connected to the main valve body 28. Figure 2 As shown, when the first cylinder chamber 26 expands and the second cylinder chamber 27 contracts, the main valve body 28 is positioned at the first position P1. The expansion of the first cylinder chamber 26 moves the main valve body 28 to the first position P1. Figure 3 As shown, when the second cylinder chamber 27 expands and the first cylinder chamber 26 contracts, the main valve body 28 is positioned at the second position P2. The expansion of the second cylinder chamber 27 causes the main valve body 28 to move to the second position P2. Hereinafter, the main valve body 28 of the four-way valve 18 being positioned at the first position P1 or the second position P2 is sometimes simply referred to as the four-way valve 18 being positioned at the first position P1 or the second position P2.

[0022] The secondary valve 30 has a housing 34 and a secondary valve body 33. The housing 34 is cylindrical. The housing 34 has a fifth port 35, a sixth port 36, a seventh port 37, and an eighth port 38. The fifth port 35 is connected to the first port 21 via a capillary tube 21t. The sixth port 36 is connected to the first cylinder chamber 26 via a capillary tube 26t. The seventh port 37 is connected to the second cylinder chamber 27 via a capillary tube 27t. The eighth port 38 is connected to the fourth port 24 via a capillary tube 24t.

[0023] The secondary valve body 33 is disposed near the center along the long side of the housing 34. The secondary valve body 33 is movable between the third position P3 and the fourth position P4 along the long side of the housing 34.

[0024] exist Figure 2 In this configuration, the auxiliary valve body 33 is positioned at the third position P3. At the third position P3, the auxiliary valve body 33 connects to the fifth port 35 and the sixth port 36. High-pressure refrigerant discharged from the compressor 2 flows into the first cylinder chamber 26 via the first port 21, capillary tube 21t, the fifth port 35, the sixth port 36, and capillary tube 26t. At the third position P3, the auxiliary valve body 33 connects to the seventh port 37 and the eighth port 38. Refrigerant in the second cylinder chamber 27 flows into the suction port of the compressor 2 via capillary tube 27t, the seventh port 37, the eighth port 38, capillary tube 24t, and the fourth port. The high-pressure first cylinder chamber 26 expands, while the low-pressure second cylinder chamber 27 contracts, and the main valve body 28 is positioned at the first position P1. The auxiliary valve body 33, positioned at the third position P3, positions the main valve body 28 at the first position P1.

[0025] exist Figure 3In this configuration, the secondary valve body 33 is positioned at the fourth position P4. At the fourth position P4, the secondary valve body 33 connects to the fifth port 35 and the seventh port 37. High-pressure refrigerant discharged from the compressor 2 flows into the second cylinder chamber 27 via the first port 21, capillary tube 21t, the fifth port 35, the seventh port 37, and capillary tube 27t. At the fourth position P4, the secondary valve body 33 connects to the sixth port 36 and the eighth port 38. Refrigerant in the first cylinder chamber 26 flows into the suction port of the compressor 2 via capillary tube 26t, the sixth port 36, the eighth port 38, capillary tube 24t, and the fourth port 24. The high-pressure second cylinder chamber 27 expands, while the low-pressure first cylinder chamber 26 contracts, and the main valve body 28 is positioned at the second position P2. The secondary valve body 33 positions the main valve body 28 at the second position P2 from the fourth position P4.

[0026] The secondary valve body 33 is connected to the plunger 32. The plunger 32 is driven by the solenoid 31 and can move along its long side. When the control unit 13 energizes the solenoid 31, such as... Figure 2 As shown, the secondary valve body 33 is positioned in the third position P3. Therefore, the main valve body 28 is positioned in the first position P1, and heating operation is implemented. When the control unit 13 disconnects the energizer 31, as... Figure 3 As shown, the secondary valve body 33 is positioned at the fourth position P4. Consequently, the main valve body 28 is positioned at the second position P2 to perform cooling or defrosting operation.

[0027] The refrigeration cycle unit 1 adjusts the number of operating outdoor units based on indoor and outdoor temperatures. Sometimes, only a portion of the outdoor units operate, while the rest remain off. For example, during heating operation, only... Figure 1 The first outdoor unit 11 is operating, while the second outdoor unit 12 is stopped. In this situation, both the first four-way valve 18 and the second four-way valve 18 are energized to the solenoid 31. Both the first four-way valve 18 and the second four-way valve 18 are in the first position P1. The high-pressure refrigerant discharged from the first compressor 2 enters not only the indoor unit 10 but also the stopped second outdoor unit 12. Because the second four-way valve 18 is in the first position P1, the intrusion of the high-pressure refrigerant is prevented by the check valve 3.

[0028] During refrigeration operation, sometimes only the first outdoor unit 11 operates, while the second outdoor unit 12 stops. In this case, the energization of both the first four-way valve 18 and the second four-way valve 18 to the solenoid 31 is disconnected. Both the first four-way valve 18 and the second four-way valve 18 are in the second position P2. Low-pressure refrigerant discharged from the indoor unit 10 enters the stopped second outdoor unit 12. With all outdoor units 11 and 12 in a stopped state, the energization of the solenoid 31 by the first four-way valve 18 and the second four-way valve 18 is disconnected. Both the first four-way valve 18 and the second four-way valve 18 are in the second position P2.

[0029] Figure 4 This is a diagram illustrating the second operation of the refrigeration cycle device. Figure 5 This is a diagram illustrating the third operation of the four-way valve. Sometimes, starting from when all outdoor units 11 and 12 have stopped or are in defrost mode, only the first outdoor unit 11 operates in heating mode, while the second outdoor unit 12 stops. The control unit 13 activates the solenoids of the first four-way valve 18 and the second four-way valve 18. (The diagram is incomplete and requires further context.) Figure 5 As shown, immediately after the secondary valve body 33 moves to the third position P3, the main valve body 28 is also positioned at the second position P2.

[0030] Sometimes, the pressure difference between the discharge pressure of the operating first compressor 2 and the discharge pressure of the stopped second compressor 2 is large. When the second four-way valve 18 is in the second position P2, the high-pressure refrigerant discharged from the first compressor 2 flows from the second port 22 of the second four-way valve 18 into the fourth port 24. The high-pressure refrigerant flows into the second cylinder chamber 27 via the capillary tube 24t, the eighth port 38, the seventh port 37, and the capillary tube 27t. On the other hand, since the high-pressure refrigerant does not flow from the second compressor 2 into the first port 21, the first cylinder chamber 26 is at low pressure. Therefore, sometimes the main valve body 28 of the second four-way valve 18 does not move to the first position P1. When the second four-way valve 18 is not in the first position P1, the second four-way valve 18 stops at the second position P2, or moves to an intermediate position between the second position P2 and the first position P1 and stops.

[0031] As described above, the high-pressure refrigerant discharged from the operating first compressor 2 enters the stopped second outdoor unit 12. Figure 4 As shown, when the second four-way valve 18 is not in the first position P1, high-pressure refrigerant enters the suction port of the second compressor 2 from the second four-way valve 18 via the reservoir 2a. In the stopped second compressor 2, the high-pressure refrigerant liquefies and remains, thus causing a refrigerant retention problem. Refrigerant retention in the second compressor 2 will cause it to malfunction upon restarting.

[0032] The control unit 13 detects a malfunction in the switching of the second four-way valve 18 as follows: When the second four-way valve 18 is not in the first position P1, high-pressure refrigerant discharged from the first compressor 2 enters the suction port of the second compressor 2. The control unit 13 receives the discharge pressure signal output from the discharge pressure sensor 14 of the first compressor 2. The control unit 13 also receives the suction pressure signal output from the suction pressure sensor 15 of the second compressor 2. When the difference between the discharge pressure of the first compressor 2 and the suction pressure of the second compressor is less than a predetermined value, the control unit 13 determines that the second four-way valve 18 is not in the first position P1.

[0033] The control unit 13 can also detect malfunction of the second four-way valve 18 as follows: When the second four-way valve 18 is in the first position P1, the high-pressure refrigerant discharged from the first compressor 2 does not enter the suction port of the second compressor 2. At this time, the temperature converted from the suction pressure of the second compressor 2 to the saturation temperature is the same as the external gas temperature. The control unit 13 receives the suction pressure signal output from the suction pressure sensor 15 of the second compressor 2. The control unit 13 receives the external gas temperature signal output from the external gas temperature sensor 17 of the second outdoor unit 12. When the difference between the temperature converted from the suction pressure to the saturation temperature and the external gas temperature is less than a specified value, the control unit 13 determines that the second four-way valve 18 is in the first position P1. Conversely, when the difference between the temperature converted from the suction pressure to the saturation temperature and the external gas temperature is greater than or equal to a specified value, the control unit 13 determines that the second four-way valve 18 is not in the first position P1.

[0034] Similarly, the control unit 13 can also determine that the second four-way valve 18 is not in the first position P1 based on the output signals of the pressure sensor and the temperature sensor. The pressure sensor is at least one of the discharge pressure sensor 14 of the second compressor 2 and the suction pressure sensor 15 of the second compressor 2. The temperature sensor is at least one of the suction temperature sensor 16 of the second compressor 2 and the external gas temperature sensor 17 of the second outdoor unit 12.

[0035] When the second four-way valve 18 is not in the first position P1, the control unit 13 moves the second four-way valve 18 to the first position P1 as follows. First, control unit 13 will Figure 5 The second four-way valve 18 shown is configured to disconnect the energization of the solenoid 31. For example... Figure 3 As shown, immediately after the secondary valve body 33 moves to the fourth position P4, the main valve body 28 is also positioned at the second position P2. Figure 4 As shown, when the second four-way valve 18 is in the second position P2, the high-pressure refrigerant discharged from the first compressor 2 flows from the second port 22 of the second four-way valve 18 into the fourth port 24. The high-pressure refrigerant then... Figure 3The capillary tube 24t, eighth port 38, sixth port 36, and capillary tube 26t shown flow into the first cylinder chamber 26. On the other hand, since high-pressure refrigerant does not flow into the first port 21 of the second four-way valve 18, the second cylinder chamber 27 is at low pressure. The first cylinder chamber 26 expands, and the second cylinder chamber 27 contracts. Thus, as... Figure 6 As shown in the diagram illustrating the fourth action of the four-way valve, the main valve body 28 of the second four-way valve 18 moves to the first position P1.

[0036] like Figure 1 As shown, when the second four-way valve 18 is in the first position P1, the high-pressure refrigerant discharged from the first compressor 2 flows from the second port 22 of the second four-way valve 18 into the first port 21. The high-pressure refrigerant then... Figure 6 The capillary tube 21t, fifth port 35, seventh port 37, and capillary tube 27t shown flow into the second cylinder chamber 27. On the other hand, since the high-pressure refrigerant does not flow into the fourth port 24 of the second four-way valve 18, the first cylinder chamber 26 is at low pressure. The second cylinder chamber 27 expands, and the first cylinder chamber 26 contracts. Thus, as... Figure 3 As shown, the main valve body 28 of the second four-way valve 18 returns to the second position P2. When the second four-way valve 18 keeps the energization of the solenoid 31 disconnected, the main valve body 28 repeatedly moves back and forth between the first position P1 and the second position P2.

[0037] like Figure 6 As shown, after the main valve body 28 of the second four-way valve 18 moves to the first position P1, the control unit 13 energizes the solenoid 31. The auxiliary valve body 33 is as follows... Figure 2 The control unit 13 moves the sub-valve body 33 to the third position P3 after positioning the sub-valve body 33 in the fourth position. Figure 1 As shown, when the second four-way valve 18 is in the first position P1, the high-pressure refrigerant discharged from the first compressor 2 flows from the second port 22 of the second four-way valve 18 into the first port 21. The high-pressure refrigerant then... Figure 2 The capillary tube 21t, fifth port 35, sixth port 36, and capillary tube 26t shown flow into the first cylinder chamber 26. On the other hand, since the high-pressure refrigerant does not flow into the fourth port 24, the second cylinder chamber 27 is at low pressure. The first cylinder chamber 26 remains in an expanded state, and the second cylinder chamber 27 remains in a contracted state. As a result, the main valve body 28 of the second four-way valve 18 remains in the first position P1.

[0038] Figure 7This is a graph showing the relationship between the compressor's suction pressure and the switching time of the four-way valve. As described above, after the main valve body 28 of the second four-way valve 18 moves to the first position P1, the control unit 13 energizes the solenoid 31. As described above, the movement of the main valve body 28 to the first position P1 is caused by the pressure of the refrigerant discharged from the first compressor 2 and flowing into the fourth port 24 of the second four-way valve 18. The pressure at the fourth port 24 of the second four-way valve 18 is the suction pressure of the second compressor 2. Figure 7 As shown, the higher the suction pressure, the longer the time it takes for the main valve body 28 to move from the second position P2 to the first position P1. Figure 7 (The shorter the solid line in the middle)

[0039] The control unit 13 sets the time for moving the auxiliary valve body 33 from the fourth position P4 to the third position P3 based on the suction pressure signal. The time for moving the auxiliary valve body 33 from the fourth position P4 to the third position P3 is the time for disconnecting the energizer 31. Figure 7 (Used as dashed lines in the middle). For example... Figure 7 As shown, the higher the suction pressure, the shorter the energizing and de-energizing time of the solenoid 31 is for the control unit 13. Compared to the movement time β of the main valve body 28, the control unit 13 extends the energizing and de-energizing time α of the solenoid 31. After the energizing and de-energizing time of the solenoid 31 has elapsed, the control unit 13 turns the energizing of the solenoid 31 on. Thus, after the main valve body 28 moves to the first position P1, the energizing of the solenoid 31 immediately becomes on, and the second four-way valve 18 remains in the first position P1.

[0040] After moving the sub-valve body 33 from the fourth position P4 to the third position P3, the control unit 13 re-checks for switching malfunction of the second four-way valve 18. Upon this re-check, if the second four-way valve 18 is not in the first position P1, the control unit 13 stops the refrigeration cycle unit 1. Alternatively, the control unit 13 can repeatedly move the sub-valve body 33 until the second four-way valve 18 is not in the first position P1, at which point the refrigeration cycle unit 1 stops. Figure 7 When the movement time of the main valve body 28 and the energization / disconnection time of the solenoid 31 are not properly set, it can be assumed that the second four-way valve 18 is not configured in the first position P1. In this case, by stopping the first outdoor unit 11, which is scheduled to operate, a malfunction of the refrigeration cycle unit 1 can be suppressed.

[0041] As described in detail above, the refrigeration cycle device 1 of the embodiment includes an indoor unit 10, a first outdoor unit 11, a second outdoor unit 12, and a control unit 13. The indoor unit 10 includes an indoor heat exchanger 4. The first outdoor unit 11 and the second outdoor unit 12 are connected in parallel with the indoor unit 10. The second outdoor unit 12 includes a compressor 2, an outdoor heat exchanger 8, and a four-way valve 18. The four-way valve 18 switches the supply destination of the refrigerant discharged from the compressor 2 between the indoor heat exchanger 4 and the outdoor heat exchanger 8. The four-way valve 18 includes a main valve 20 having a main valve body 28 and a secondary valve 30 having a secondary valve body 33. The main valve body 28 is movable between a first position P1 and a second position P2. The first position P1 is the position where the refrigerant discharged from the compressor 2 is supplied to one of the indoor heat exchanger 4 and the outdoor heat exchanger 8. The second position P2 is the position where the refrigerant discharged from the compressor 2 is supplied to the other of the indoor heat exchanger 4 and the outdoor heat exchanger 8. The secondary valve body 33 is driven by the solenoid 31 and can move between the third position P3 and the fourth position P4. The third position P3 is the position where the main valve body 28 is positioned at the first position P1. The fourth position P4 is the position where the main valve body 28 is positioned at the second position P2. When the first outdoor unit 11 is operating and the second outdoor unit 12 is stopped, when the main valve body 28 is not in the first position P1, the control unit 13 positions the secondary valve body 33 in the fourth position P4 and then moves the secondary valve body 33 to the third position P3.

[0042] The main valve 20 has a first port 21 connected to the discharge port of the compressor 2. The main valve 20 has a second port 22 connected to one of the indoor heat exchanger 4 and the outdoor heat exchanger 8. The main valve 20 has a third port 23 connected to the other of the indoor heat exchanger 4 and the outdoor heat exchanger 8. The main valve 20 has a fourth port 24 connected to the suction port of the compressor 2. The main valve 20 has a first cylinder chamber 26 that expands to move the main valve body 28 to a first position P1. The main valve 20 has a second cylinder chamber 27 that expands to move the main valve body 28 to a second position P2. The main valve body 28 is connected to the first port 21 and the second port 22, and to the third port 23 and the fourth port 24 at the first position P1. The main valve body 28 is connected to the first port 21 and the third port 23, and to the second port 22 and the fourth port 24 at the second position P2. The secondary valve 30 has a fifth port 35 communicating with the first port 21. The secondary valve 30 has a sixth port 36 communicating with the first cylinder chamber 26. The secondary valve 30 has a seventh port 37 communicating with the second cylinder chamber 27. The secondary valve 30 has an eighth port 38 communicating with the fourth port 24. The auxiliary valve body 33 is connected to the fifth port 35 and the sixth port 36, and to the seventh port 37 and the eighth port 38 at the third position P3. The auxiliary valve body 33 is connected to the fifth port 35 and the seventh port 36, and to the sixth port 36 and the eighth port 38 at the fourth position P4.

[0043] By positioning the secondary valve body 33 in the fourth position P4, the main valve body 28 is moved to the first position P1. Then, by moving the secondary valve body 33 to the third position P3, the main valve body 28 remains in the first position P1. This eliminates the malfunction of the four-way valve 18 in the stopped second outdoor unit 12.

[0044] The second outdoor unit 12 has an intake pressure sensor 15 that outputs an intake pressure signal corresponding to the intake pressure of the compressor 2. The control unit 13 sets the time for moving the sub-valve body 33 from the fourth position P4 to the third position P3 based on the intake pressure signal.

[0045] Because the suction pressure of the compressor 2 of the stopped second outdoor unit 12 changes, the time until the main valve body 28 moves to the first position P1 changes. The control unit 13 sets the time from when the auxiliary valve body 33 is positioned in the fourth position P4 to when it moves to the third position P3 based on the suction pressure signal received from the suction pressure sensor 15. Thus, after the main valve body 28 moves to the first position P1, the auxiliary valve body 33 is positioned in the third position P3, and the main valve body 28 remains in the first position P1.

[0046] The first outdoor unit 11 has a discharge pressure sensor 14, which outputs a discharge pressure signal corresponding to the discharge pressure of the compressor 2 of the first outdoor unit 11. The second outdoor unit 12 has a suction pressure sensor 15 that outputs a suction pressure signal corresponding to the suction pressure of the compressor 2. When the difference between the discharge pressure and the suction pressure is less than a predetermined value, the control unit 13 determines that the main valve body 28 is not in the first position P1.

[0047] When the main valve body 28 is not in the first position P1, the high-pressure refrigerant discharged from the first compressor 2 of the first outdoor unit 11 enters the suction port of the second compressor 2 of the second outdoor unit 12. When the difference between the discharge pressure of the first compressor 2 and the suction pressure of the second compressor 2 is less than a specified value, it can be determined that the main valve body 28 is not in the first position P1.

[0048] The second outdoor unit 12 has a pressure sensor and a temperature sensor. The pressure sensor is at least one of the discharge pressure sensor 14 of the compressor 2 and the suction pressure sensor 15 of the compressor 2. The temperature sensor is at least one of the suction temperature sensor 16 of the compressor 2 and the external gas temperature sensor 17. Based on the output signals of the pressure sensor and the temperature sensor, the control unit 13 determines that the main valve body 28 is not in the first position P1.

[0049] When the main valve body 28 is in the first position P1, the high-pressure refrigerant discharged from the first compressor 2 does not enter the suction port of the second compressor 2. At this time, the temperature converted from the suction pressure of the second compressor 2 to the saturation temperature is the same as the external gas temperature. Based on the output signals of the pressure sensor and the temperature sensor, it can be determined that the main valve body 28 is not in the first position P1.

[0050] After the secondary valve body 33 is positioned in the fourth position P4 and then moved to the third position P3, when the main valve body 28 is not in the first position P1, the control unit 13 stops the first outdoor unit 11. This suppressed the malfunction of the refrigeration cycle device 1.

[0051] According to at least one embodiment described above, a control unit 13 is provided that moves the sub-valve body 33 to the third position P3 after the sub-valve body 33 is positioned in the fourth position P4. This eliminates the possibility of malfunctioning switching of the four-way valve 18 in the stopped second outdoor unit 12.

[0052] Several embodiments of the present invention have been described, but these embodiments are presented by way of example only and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are all included within the scope and spirit of the present invention, and similarly, within the scope of the invention described in the claims of this patent and its equivalents. Label Explanation

[0053] P1…First position, P2…Second position, P3…Third position, P4…Fourth position, 1…Refrigeration cycle unit, 2…Compressor, 4…Indoor heat exchanger, 8…Outdoor heat exchanger, 10…Indoor unit, 11…First outdoor unit, 12…Second outdoor unit, 13…Control unit, 14…Discharge pressure sensor, 15…Intake pressure sensor, 16…Intake temperature sensor, 17…External gas temperature sensor, 18…Four-way valve, 20…Main valve, 21…First port, 22…Second port, 23…Third port, 24…Fourth port, 26…First cylinder chamber, 27…Second cylinder chamber, 28…Main valve body, 30…Subsidiary valve, 31…Solenoid, 33…Subsidiary valve body, 35…Fifth port, 36…Sixth port, 37…Seventh port, 38…Eighth port.

Claims

1. A refrigeration cycle device, characterized in that, It includes: an indoor unit with an indoor heat exchanger; a first outdoor unit and a second outdoor unit connected in parallel with the indoor unit; and a control unit. The first outdoor unit and the second outdoor unit each have: a compressor; an outdoor heat exchanger; And a four-way valve that switches the refrigerant discharged from the compressor to its supply destination between the indoor heat exchanger and the outdoor heat exchanger. The four-way valve includes: a main valve having a main valve body; And a secondary valve with a secondary valve body, The main valve body is movable between a first position supplying refrigerant discharged from the compressor to the indoor heat exchanger and a second position supplying refrigerant discharged from the compressor to the outdoor heat exchanger. The secondary valve body is driven by a solenoid and can move between a third position where the main valve body is positioned in the first position and a fourth position where the main valve body is positioned in the second position. When the first outdoor unit is operating and the second outdoor unit is stopped, when the main valve body of the first outdoor unit is in the first position and the main valve body of the second outdoor unit is not in the first position, the control unit configures the secondary valve body of the second outdoor unit in the fourth position and then moves the secondary valve body of the second outdoor unit to the third position.

2. The refrigeration cycle device as described in claim 1, characterized in that, The main valve has: a first port connected to the discharge port of the compressor; a second port connected to the indoor heat exchanger; a third port connected to the outdoor heat exchanger; a fourth port connected to the suction port of the compressor; and a first cylinder chamber that moves the main valve body to the first position by expansion. And the second cylinder chamber that moves the main valve body to the second position by expansion. The main valve body connects the first port and the second port, and the third port and the fourth port at the first position, and connects the first port and the third port, and the second port and the fourth port at the second position. The secondary valve has: a fifth port communicating with the first port; a sixth port communicating with the first cylinder chamber; a seventh port communicating with the second cylinder chamber; and an eighth port communicating with the fourth port. The secondary valve body is connected to the fifth port and the sixth port, and to the seventh port and the eighth port at the third position, and to the fifth port and the seventh port, and to the sixth port and the eighth port at the fourth position.

3. The refrigeration cycle device as described in claim 1 or 2, characterized in that, The second outdoor unit has a suction pressure sensor that outputs a suction pressure signal corresponding to the suction pressure of the compressor in the second outdoor unit. The control unit sets the time for moving the secondary valve of the second outdoor unit from the fourth position to the third position based on the suction pressure signal.

4. The refrigeration cycle device as described in claim 1 or 2, characterized in that, The first outdoor unit has a discharge pressure sensor that outputs a discharge pressure signal corresponding to the discharge pressure of the compressor in the first outdoor unit. The second outdoor unit has a suction pressure sensor that outputs a suction pressure signal corresponding to the suction pressure of the compressor in the second outdoor unit. When the difference between the discharge pressure and the intake pressure is less than a predetermined value, the control unit determines that the main valve body of the second outdoor unit is not in the first position.

5. The refrigeration cycle device as described in claim 1 or 2, characterized in that, The second outdoor unit includes: a pressure sensor; and a temperature sensor. The pressure sensor is at least one of the discharge pressure sensor of the compressor of the second outdoor unit and the suction pressure sensor of the compressor of the second outdoor unit. The temperature sensor is at least one of the compressor intake temperature sensor and the external gas temperature sensor of the second outdoor unit. Based on the output signals of the pressure sensor and the temperature sensor, the control unit determines that the main valve body of the second outdoor unit is not in the first position.

6. The refrigeration cycle device as described in claim 1 or 2, characterized in that, After the secondary valve body of the second outdoor unit is positioned in the fourth position and then moved to the third position, when the main valve body of the second outdoor unit is not in the first position, the control unit stops the first outdoor unit.

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