Heat pump device and heat source unit

Abstract

To provide a heat pump device that restrains the generation of unusual noise caused by a check valve, and can be restrained from being upsized, and a heat source unit thereof.SOLUTION: A heat pump device comprises a circuit board equipped with a DC power circuit, a first expansion valve connector connected to a first expansion valve, a second expansion valve connector connected to a second expansion valve, a first opening / closing valve connector connected to a first opening / closing valve, and a second opening / closing valve connector connected to a second opening / closing valve. The circuit board is provided with a wiring pattern connecting the DC power circuit, the first expansion valve connector, and the first opening / closing valve connector. The wiring pattern comprises a first common wiring part common to the first expansion valve connector and the first opening / closing valve connector, and first branch wiring parts branching from the first common wiring part to the first expansion valve connector and the first opening / closing valve connector.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a heat pump apparatus in which a plurality of indoor units are connected in parallel to one outdoor unit (heat source unit), and to the heat source unit. [Background technology]

[0002] A heat pump apparatus is known in which a plurality of indoor units are connected in parallel to one outdoor unit (see, for example, Patent Document 1). Also known is a heat pump apparatus in which one of the plurality of indoor units functions as a hot water heater.

[0003] In a heat pump device with a hot water supply function, when the hot water supply side is stopped during heating operation in winter, the refrigerant is cooled in the water-refrigerant heat exchanger on the hot water supply side due to the drop in water temperature, and liquefied refrigerant may accumulate in the indoor unit on the hot water supply side. In this case, as described in Patent Document 2, for example, by arranging an expansion valve in the liquid pipe of each indoor unit and an on-off valve in the gas pipe of each indoor unit, and closing the expansion valve and on-off valve on the indoor unit that is stopped, it is possible to prevent refrigerant from flowing into that indoor unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-20064 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-236392 Summary of the Invention [Problem to be solved by the invention]

[0005] The on-off valves used in heat pump systems are required to operate even when there is a difference in refrigerant pressure between the inlet and outlet sides. For this reason, pilot-operated solenoid valves (also known as one-way solenoid valves) with independent plungers (moving iron cores) and main valves are typically used. In such cases, a check valve that allows refrigerant to flow in the opposite direction is installed in parallel with the one-way solenoid valve to enable reverse cycle operation. However, because the compressors used in heat pump systems repeatedly draw, compress, and discharge the refrigerant, the refrigerant pressure pulsates in the refrigerant circuit. When this pulsation becomes too great, the check valve repeatedly opens and closes, causing abnormal noise.

[0006] Furthermore, providing a check valve in addition to an expansion valve and an on-off valve increases the size of the heat source unit of the heat pump device they are installed in. Furthermore, when a high voltage is applied to the on-off valve or solenoid valve, the number of high-voltage sections in the valve drive circuit increases, so it is necessary to increase the wiring pattern width and pattern spacing on the circuit board on which the valve drive circuit is formed, which inevitably increases the size of the circuit board.

[0007] In view of the above circumstances, an object of the present invention is to provide a heat pump apparatus and a heat source unit thereof that can suppress the generation of abnormal noise caused by a check valve and prevent the apparatus from becoming large in size. [Means for solving the problem]

[0008] A heat pump device according to one aspect of the present invention includes a first indoor unit having a first indoor heat exchanger, a second indoor unit having a second indoor heat exchanger, and a heat source unit. The heat source unit includes a compressor, an outdoor heat exchanger, a first liquid pipe connecting the outdoor heat exchanger and the first indoor heat exchanger, a second liquid pipe connecting the outdoor heat exchanger and the second indoor heat exchanger, a first gas pipe connecting the compressor and the first indoor heat exchanger, a second gas pipe connecting the compressor and the second indoor heat exchanger, a first expansion valve arranged in the first liquid pipe, a second expansion valve arranged in the second liquid pipe, a first on-off valve arranged in the first gas pipe, a second on-off valve arranged in the second gas pipe, and a control device that controls the compressor, the first expansion valve, the second expansion valve, the first on-off valve, and the second on-off valve. The first expansion valve and the second expansion valve are electronic expansion valves whose opening degrees are adjusted by the passage of a direct current. The first on-off valve and the second on-off valve are direct acting solenoid valves that open and close when a direct current is passed through them. The control device has a circuit board. The circuit board is mounted with a DC power supply circuit, a first expansion valve connector connected to the first expansion valve, a second expansion valve connector connected to the second expansion valve, a first on-off valve connector connected to the first on-off valve, and a second on-off valve connector connected to the second on-off valve. The circuit board is provided with wiring patterns connecting the DC power supply circuit and the first expansion valve connector, the DC power supply circuit and the second expansion valve connector, the DC power supply circuit and the first on-off valve connector, and the DC power supply circuit and the second on-off valve connector. The wiring pattern has a first common wiring portion common to the first expansion valve connector and the first on-off valve connector, and a first branch wiring portion branching from the first common wiring portion to the first expansion valve connector and the first on-off valve connector.

[0009] In the present invention, direct-acting solenoid valves that allow refrigerant to flow in both directions are used as the first and second on-off valves, eliminating the need for check valves. This prevents noise caused by pulsations in the refrigerant pressure. Furthermore, because the wiring pattern includes a first common wiring portion and a first branch wiring portion, the area required to form the wiring pattern is reduced, thereby preventing the circuit board from becoming larger. [Effects of the Invention]

[0010] According to the present invention, it is possible to suppress the generation of abnormal noise caused by the check valve and also to prevent the device from becoming larger in size. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a refrigerant circuit diagram showing an example of the configuration of a heat pump device according to an embodiment of the present invention. [Figure 2] 1 is a system diagram showing an example of the configuration of a water heater; [Figure 3] FIG. 2 is a block diagram showing the configuration of a control device. [Figure 4] FIG. 1 is a circuit diagram showing an on-off valve in which a check valve is connected in parallel to an AC solenoid valve. [Figure 5] FIG. 1 is a circuit diagram showing an example of the configuration of a drive circuit for a DC solenoid valve. [Figure 6] 3 is a schematic diagram showing an example of a circuit board of a heat source unit on which the drive circuit is mounted. FIG. [Figure 7] 4 is a schematic diagram showing an example of a wiring pattern connecting a switching power supply circuit to a first expansion valve connector and a first on-off valve connector. FIG. [Figure 8] 4 is a schematic enlarged view of a main part of a circuit board for explaining the operation of the present invention. FIG. [Figure 9] 1A and 1B are schematic cross-sectional side views showing the structure of a first on-off valve and a second on-off valve, in which (A) shows the open valve state (state when not energized) and (B) shows the closed valve state (state when energized). [Figure 10] 10 is a diagram showing the time-dependent changes in the operating state of each part of the heat source unit when starting a heating operation. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] 1 is a refrigerant circuit diagram showing an example of the configuration of a heat pump device 100 according to one embodiment of the present invention. The entire heat pump device 100 of this embodiment will be described briefly below with reference to FIG.

[0014] [Overall configuration of heat pump equipment] As shown in FIG. 1, the heat pump device 100 includes a heat source unit 1, a first indoor unit 2A, and a second indoor unit 2B.

[0015] The heat source unit 1 corresponds to an outdoor unit and includes a compressor 11, a four-way valve 12, an outdoor heat exchanger 13, an accumulator 14, a refrigerant circuit 10 having a first expansion valve E1, a second expansion valve E2, a first on-off valve V1, and a second on-off valve V2, an outdoor fan 13F, and a control device 90.

[0016] The compressor 11 is a variable capacity compressor with a variable operating capacity driven by a motor (not shown) whose rotation speed is controlled by an inverter. The refrigerant discharge side of the compressor 11 is connected to port a of the four-way valve 12 via a discharge pipe 15. The refrigerant suction side of the compressor 11 is connected to the refrigerant outflow side of the accumulator 14 via a suction pipe 18.

[0017] The four-way valve 12 is a flow path switching valve that switches the refrigerant flow direction in the refrigerant circuit 10, and has four ports a, b, c, and d. As described above, port a is connected to the refrigerant discharge side of the compressor 11 by discharge piping 15. Port b is connected to one refrigerant inlet / outlet of the outdoor heat exchanger 13 by refrigerant piping 16. Port c is connected to the refrigerant inlet / outlet side of the accumulator 14 by refrigerant piping 17. Port d is connected to one refrigerant inlet / outlet of a first indoor heat exchanger 21 (described later) by a gas pipe G and a first gas branch piping G1, and is also connected to one refrigerant inlet / outlet of a second indoor heat exchanger 22 (described later) by the gas pipe G and a second gas branch piping G2.

[0018] The first gas branch pipe G1 is one of the refrigerant pipes branching at a branch point A1 of the gas pipe G, and corresponds to the first gas pipe connecting the outdoor heat exchanger 13 and the first indoor heat exchanger 21. The second gas branch pipe G2 is the other refrigerant pipe branching at a branch point A2 of the gas pipe G, and corresponds to the second gas pipe connecting the outdoor heat exchanger 13 and the second indoor heat exchanger 22.

[0019] The outdoor heat exchanger 13 exchanges heat between the refrigerant and outside air taken into the heat source unit 1 by the rotation of an outdoor fan 13F, which will be described later. As described above, one refrigerant inlet and outlet of the outdoor heat exchanger 13 is connected to port b of the four-way valve 12 by refrigerant piping 16. The other refrigerant inlet and outlet of the outdoor heat exchanger 13 is connected to the other refrigerant inlet and outlet of a first indoor heat exchanger 21, which will be described later, by a liquid pipe L and a first liquid branch pipe L1, and is also connected to the other refrigerant inlet and outlet of a second indoor heat exchanger 22, which will be described later, by a liquid pipe L and a second liquid branch pipe L2.

[0020] The outdoor fan 13F is disposed near the outdoor heat exchanger 13. The outdoor fan 13F is driven by a fan motor (not shown), takes in outside air from an intake port (not shown) of the heat source unit 1, exchanges heat with the refrigerant in the outdoor heat exchanger 13, and discharges the outside air to the outside of the heat source unit 1 from an outlet port (not shown) of the heat source unit 1.

[0021] The first branched liquid pipe L1 is one of the refrigerant pipes branching off at branch point A2 of the liquid pipe L, and corresponds to the first liquid pipe connecting the outdoor heat exchanger 13 and the first indoor heat exchanger 21. The second branched liquid pipe L2 is the other of the refrigerant pipes branching off at branch point A2 of the liquid pipe L, and corresponds to the second liquid pipe connecting the outdoor heat exchanger 13 and the second indoor heat exchanger 22.

[0022] The first expansion valve E1 and the second expansion valve E2 are electronic expansion valves whose openings are adjusted by applying a DC voltage. The openings of the first expansion valve E1 and the second expansion valve E2 are controlled, for example, based on the number of pulses applied to a stepping motor (not shown).

[0023] The first expansion valve E1 is disposed in the first liquid branch pipe L1 and reduces the pressure of the refrigerant flowing through the first liquid branch pipe L1. The opening degree of the first expansion valve E1 is adjusted according to the operating capacity required by the first indoor unit 2A. The second expansion valve E2 is disposed in the second liquid branch pipe L2 and reduces the pressure of the refrigerant flowing through the second liquid branch pipe L2. The opening degree of the second expansion valve E2 is adjusted according to the operating capacity required by the second indoor unit 2B.

[0024] The first on-off valve V1 is an on-off valve that can block the flow of refrigerant in the first gas branch pipe G1. The first on-off valve V1 is open when the first indoor unit 2A is operating and closed when the first indoor unit 2A is stopped. The second on-off valve V2 is an on-off valve that can block the flow of refrigerant in the second gas branch pipe G2. The second on-off valve V2 is open when the second indoor unit 2B is operating and closed when the indoor unit 2B is stopped.

[0025] As will be described later, the first on-off valve V1 and the second on-off valve V2 are direct-acting solenoid valves that open and close when a direct current is applied. In this embodiment, the first on-off valve V1 and the second on-off valve V2 are normally open direct-acting solenoid valves that close when energized.

[0026] The first on-off valve V1 is arranged in the first gas branch pipe G1, and the second on-off valve V2 is arranged in the second gas branch pipe G2. The first on-off valve V1 is open when the first indoor unit 2A is operating and closed when the first indoor unit 2A is not operating. The second on-off valve V2 is open when the second indoor unit 2A is operating and closed when the second indoor unit 2B is not operating.

[0027] The first indoor unit 2A has a first indoor heat exchanger 21. The second indoor unit 2B has a second indoor heat exchanger 22. In this embodiment, the first indoor heat exchanger 21 is an air-refrigerant heat exchanger that exchanges heat between the air (indoor air) in the indoor space in which the first indoor unit 2A is installed and a refrigerant. On the other hand, the second indoor unit 2B is, for example, the water heater 500 shown in FIG. 2, and the second indoor heat exchanger 22 is a water-refrigerant heat exchanger that exchanges heat between the water circulating through the water heater 500 and a refrigerant.

[0028] 2 is a system diagram showing an example of the configuration when the second indoor unit 2B is used as a hot water heater 500. The hot water heater 500 has a hot water storage tank 51, a water pipe 52 that supplies city water to the hot water storage tank 51, a water circuit 50 including a pump 53 that circulates water between the hot water storage tank 51 and the second indoor heat exchanger (water-refrigerant heat exchanger) 22, and a hot water supply pipe 54 that supplies hot water in the hot water storage tank 51 to the outside. A mixing valve 55 is provided in the hot water supply pipe 54 for mixing the hot water drawn out from the hot water storage tank 51 with water in the water pipe 52.

[0029] The second indoor unit 2B is not limited to the above example, and may be a panel heater for floor heating instead of the hot water storage tank 51, or may be a fan coil unit (FCU) further equipped with a water-air heat exchanger that exchanges heat between the water circulating through the water circuit and the indoor air.

[0030] Furthermore, the second indoor heat exchanger 22 may be an air-refrigerant heat exchanger, similar to the first indoor heat exchanger 21. That is, both the first indoor heat exchanger 21 and the second indoor heat exchanger 22 may be air-refrigerant heat exchangers, or at least one of the first indoor heat exchanger 21 and the second indoor heat exchanger 22 may be a water-refrigerant heat exchanger.

[0031] The heat pump device 100 is provided with various sensors (not shown). For example, in the heat source unit 1, the discharge piping 15 is provided with a high-pressure sensor that detects the pressure of the refrigerant discharged from the compressor 11, and a discharge temperature sensor that detects the temperature of the refrigerant discharged from the compressor 11. The suction piping 18 is provided with a low-pressure sensor that detects the pressure of the refrigerant sucked into the compressor 11, and an suction temperature sensor that detects the temperature of the refrigerant sucked into the compressor 11. Furthermore, the outdoor heat exchanger 13 is provided with a heat exchanger temperature sensor that detects the temperature of the refrigerant flowing through the outdoor heat exchanger 13. And, near an inlet (not shown) of the heat source unit 1, an outdoor air temperature sensor is provided that detects the temperature of the outdoor air flowing into the heat source unit 1, i.e., the outdoor air temperature.

[0032] The first indoor unit 2A is provided with a heat exchanger temperature sensor for detecting the temperature of the refrigerant flowing through the indoor heat exchanger 21, and a room temperature sensor for detecting the room temperature. The second indoor unit 2B is provided with a heat exchanger temperature sensor for detecting the temperature of the refrigerant flowing through the indoor heat exchanger 22, water temperature sensors for detecting the temperatures of the water flowing into and out of the indoor heat exchanger 22, and a hot water storage tank temperature sensor for detecting the temperature of the water stored in the hot water storage tank 51.

[0033] The control device 90 is a heat source unit control device provided in the heat source unit 1, and is mounted on a control board stored in an electrical component box (not shown) of the heat source unit 1. Fig. 3 is a block diagram showing the configuration of the control device 90. As shown in the figure, the control device 90 has a CPU (Central Processing Unit) 91, a memory unit 92, a communication unit 93, a sensor input unit 94, and a rotation speed detection unit 95.

[0034] The memory unit 92 is a non-volatile memory such as a flash memory, and stores the control program and control parameters of the heat source unit 1, detection values ​​corresponding to detection signals from various sensors, the control status of each device provided in the heat source unit 1 such as the compressor 11 and the outdoor fan 13F, and the control status of the first indoor unit 2A and the second indoor unit 2B obtained via the communication unit 93.

[0035] The communication unit 93 is an interface that communicates with the first indoor unit 2A and the second indoor unit 2B. The sensor input unit 94 takes in detection results from various sensors in the heat source unit 1 and outputs them to the CPU 91. The rotation speed detection unit 95 detects the rotation speed of the motor of the compressor 11 and outputs it to the CPU 91. The rotation speed detection unit 95 may be configured to directly detect the rotation speed of the motor using an encoder or the like attached to the drive shaft of the motor, or may be configured to detect the rotation speed of the motor from the drive current supplied to the motor. In the following description, the rotation speed of the compressor 11 refers to the rotation speed of the motor.

[0036] The CPU 91 is a control unit that controls each device of the heat source unit 1, including the compressor 11, by executing a program stored in the storage unit 92. The program is pre-installed in the control device 90. Alternatively, the program may be installed via the Internet or the like.

[0037] The CPU 91 receives the detection results of the sensors in the heat source unit 1 described above via the sensor input unit 94. Furthermore, the CPU 91 receives control signals transmitted from the first indoor unit 2A and the second indoor unit 2B via the communication unit 93. The control signals transmitted from the first indoor unit 2A and the second indoor unit 2B include the operating capacities required by the first indoor unit 2A and the second indoor unit 2B. Based on the received detection results and control signals, the CPU 91 controls the drive of the compressor 11, the outdoor fan 13F, and the like, for example, by setting the command rotation speed at which these are driven. Furthermore, the CPU 91 controls the switching of the four-way valve 12 based on the received detection results and control signals.

[0038] Furthermore, the CPU 91 controls the opening degrees of the first expansion valve E1 and the second expansion valve E2 and the opening and closing of the first on-off valve V1 and the second on-off valve V2 based on the captured detection results and control signals. In particular, in this embodiment, when the CPU 91 operates either the first indoor unit 2A or the second indoor unit 2B, it stops the other. In other words, the first indoor unit 2A and the second indoor unit 2B are not operated simultaneously, and only one of them is operated.

[0039] [Heat pump device operation] Next, a description will be given of the basic operation of the heat pump device 100. Here, a cooling operation, a heating operation, and a hot water supply operation will be described.

[0040] (Cooling operation) When the heat pump apparatus 100 performs cooling operation using the first indoor unit 2A, for example, the four-way valve 12 is switched to the state shown by the solid line in Fig. 1, i.e., state 2, in which port a and port b are connected and port c and port d are connected. Also, the second expansion valve E2 is fully closed, the first on-off valve V1 is open, and the second on-off valve V2 is closed. Adjustment of the opening of the first expansion valve E1 will be described later.

[0041] In this state, the compressor 11 is driven to circulate the refrigerant through the refrigerant circuit 10. At this time, the outdoor heat exchanger 13 functions as a condenser, and the first indoor heat exchanger 21 functions as an evaporator. Here, the second expansion valve E2 is fully closed to prevent refrigerant from flowing into the second indoor heat exchanger 22 of the second indoor unit 2B, whose operation is stopped.

[0042] The high-temperature, high-pressure refrigerant discharged from the compressor 11 flows into the four-way valve 12 through the discharge pipe 15, and then flows from the four-way valve 12 through the refrigerant piping 16 into the outdoor heat exchanger 13. The refrigerant that has flowed into the outdoor heat exchanger 13 exchanges heat with outside air that has been drawn into the heat source unit 1 by the rotation of the outdoor fan 13F, and is condensed.

[0043] The refrigerant flowing out of the outdoor heat exchanger 13 flows through the liquid pipe L and the first liquid branch pipe L1, and is reduced in pressure when passing through the first expansion valve E1. The opening degree of the first expansion valve E1 is set so that the discharge temperature of the compressor 11 becomes the target discharge temperature. The refrigerant that has passed through the first expansion valve E1 flows into the first indoor heat exchanger 21, where it exchanges heat with the indoor air and evaporates. The refrigerant that has flowed out of the first indoor heat exchanger 21 flows through the first gas branch pipe G1 and the first on-off valve V1, which is in an open state, to the gas pipe G. The refrigerant that has flowed into the gas pipe G flows through the four-way valve 12, refrigerant pipe 17, accumulator 14, and suction pipe 18, and is sucked into the compressor 11 and compressed again.

[0044] (Heating operation) When the heat pump apparatus 100 performs heating operation using the first indoor unit 2A, the four-way valve 12 is switched to the state shown by the dashed lines in Fig. 1, i.e., state 1, in which port a communicates with port d and port b communicates with port c. In addition, the second expansion valve E2 is fully opened, the first on-off valve V1 is open, and the second on-off valve V2 is closed. Adjustment of the opening of the first expansion valve E1 will be described later.

[0045] In this state, the compressor 11 is driven to circulate the refrigerant through the refrigerant circuit 10. At this time, the outdoor heat exchanger 13 functions as an evaporator, and the first indoor heat exchanger 21 functions as a condenser. Here, by fully opening the second expansion valve E2, accumulation of refrigerant in the second indoor heat exchanger 22 of the second indoor unit 2B, which is not operating, is prevented.

[0046] The high-temperature, high-pressure refrigerant discharged from the compressor 11 flows through the discharge pipe 15 into the four-way valve 12, and then flows from the four-way valve 12 through the gas pipe G and the first gas branch pipe G1, and the first on-off valve V1 which is fully open, into the first indoor heat exchanger 21. The refrigerant that has flowed into the first indoor heat exchanger 21 exchanges heat with the indoor air and condenses.

[0047] The refrigerant flowing out of the first indoor heat exchanger 21 flows through the first liquid branch pipe L1 and is reduced in pressure when passing through the first expansion valve E1. The opening degree of the first expansion valve E1 is set so that the discharge temperature of the compressor 11 becomes the target discharge temperature. The refrigerant that has passed through the first expansion valve E1 flows through the liquid pipe L into the outdoor heat exchanger 13, where it exchanges heat with outside air and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger 13 flows into the refrigerant pipe 16, flows through the four-way valve 12, refrigerant pipe 17, accumulator 14, and suction pipe 18, and is drawn into the compressor 11 and compressed again.

[0048] (Hot water operation) When the heat pump apparatus 100 performs hot water supply operation in the second indoor unit 2B, the four-way valve 12 is switched to the state shown by the dashed lines in Fig. 1, i.e., state 1 in which port a communicates with port d and port b communicates with port c. Also, the first expansion valve E1 is fully opened, the first on-off valve V1 is closed, and the second on-off valve V2 is open. Adjustment of the opening of the second expansion valve E2 will be described later.

[0049] In this state, driving the compressor 11 causes refrigerant to circulate through the refrigerant circuit 10, and driving the pump 53 causes water to circulate through the water circuit 50. At this time, the outdoor heat exchanger 13 functions as an evaporator, and the second indoor heat exchanger 22 functions as a condenser. Here, by fully opening the first expansion valve E1, accumulation of refrigerant in the first indoor heat exchanger 21 of the first indoor unit 2A, which is not operating, is prevented.

[0050] The high-temperature, high-pressure refrigerant discharged from the compressor 11 flows into the four-way valve 12 through the discharge pipe 15, and then flows from the four-way valve 12 through the gas pipe G and the first gas branch pipe G2, and the second on-off valve V2 in an open state, into the second indoor heat exchanger 22. The refrigerant that has flowed into the second indoor heat exchanger 22 exchanges heat with water sent from the hot water storage tank 51 by the pump 53, and is condensed. The water in the hot water storage tank 501 is heated by heat exchange with the refrigerant in the second indoor heat exchanger 22, and becomes hot water at a predetermined temperature.

[0051] Meanwhile, the refrigerant flowing out of the second indoor heat exchanger 22 flows through the second liquid branch pipe L2 and is reduced in pressure when passing through the second expansion valve E2. The opening degree of the second expansion valve E2 is set so that the discharge temperature of the compressor 11 becomes the target discharge temperature. The refrigerant that has passed through the second expansion valve E2 flows through the liquid pipe L into the outdoor heat exchanger 13, where it exchanges heat with outside air and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger 13 flows into the refrigerant pipe 16, flows through the four-way valve 12, refrigerant pipe 17, accumulator 14, and suction pipe 18, and is drawn into the compressor 11 and compressed again.

[0052] [On-off valve] A pilot solenoid valve (also called a one-way solenoid valve 61) that operates based on the refrigerant pressure difference between the inlet and outlet sides of the valve is sometimes used as an on-off valve in a heat pump device. The one-way solenoid valve 61 has an independent plunger (moving iron core) and main valve, and the main valve opens based on the refrigerant pressure difference between the inlet and outlet sides of the valve. For example, when the refrigerant circuit is in a state where refrigerant is trying to flow in the direction of arrow A1 shown in Figure 4, if the inlet side X of the valve is connected to the upstream side and the outlet side Y of the valve is connected to the downstream side, the refrigerant pressure at the inlet side 61A of the valve becomes higher than the refrigerant pressure at the outlet side Y of the valve, opening the one-way solenoid valve 61 and allowing the refrigerant to flow in the direction of arrow A1. 4, when the refrigerant circuit is in a state where the refrigerant is attempting to flow in the direction of arrow A2, which is the opposite direction to arrow A1, the one-way solenoid valve 61 cannot open because the magnitude relationship between the refrigerant pressure on the inlet side X of the valve and the refrigerant pressure on the outlet side Y of the valve is opposite to that when the refrigerant is attempting to flow in the direction of arrow A1, and the flow of refrigerant is blocked. Therefore, when the one-way solenoid valve 61 is provided at a location in the refrigerant circuit where the refrigerant flow direction changes by switching the four-way valve, a check valve 62 that allows refrigerant to flow only in the direction of arrow A2 is provided in parallel with the one-way solenoid valve 61, so that the refrigerant flow is not blocked whether the refrigerant flow is in the direction of arrow A1 or the direction of arrow A2.

[0053] However, because the compressor used in the heat pump device repeatedly draws, compresses, and discharges the refrigerant, the refrigerant pressure pulsates in the refrigerant circuit. At this time, the pressure applied to the refrigerant inlet and outlet sides of the check valve 62 also fluctuates in accordance with the refrigerant pressure pulsation. This pressure fluctuation causes the check valve 62 to open and close minutely, and each time the valve opens and closes, the valve hits the valve seat, generating abnormal noise.

[0054] To address the above-described problems, this embodiment employs direct-acting solenoid valves as the first on-off valve V1 and the second on-off valve V2, which can open and close without requiring a refrigerant pressure difference between the inlet and outlet sides of the valve and allow refrigerant to flow in both directions (both directions of arrows A1 and A2 shown in FIG. 4). Direct-acting solenoid valves are solenoid valves (hereinafter also referred to as DC solenoid valves) that operate the valve directly with a plunger that is excited by the passage of direct current, and because they allow refrigerant to flow in both directions, there is no need to use a check valve 62. This prevents abnormal noise caused by pulsation of the refrigerant pressure.

[0055] When DC solenoid valves are used for the first on-off valve V1 and the second on-off valve V2, the drive circuit that supplies drive power to these DC solenoid valves may also supply drive power to other devices in the heat source unit 1 (for example, the compressor 11, the four-way valve 12, the outdoor fan 13F, the first expansion valve E1, the second expansion valve E2, the control device 90, and other sensors). The circuit board of the drive circuit must be provided with wiring patterns and connector components for supplying power to each of the above-mentioned devices. Providing wiring patterns and connector components according to the number of devices to which drive power is supplied increases the size of the circuit board, so it is necessary to minimise the width and spacing of the wiring patterns as much as possible to minimise the size of the circuit board.

[0056] FIG. 5 is a circuit diagram showing an example of the configuration of a drive circuit 30 for a DC solenoid valve, and FIG. 6 is a schematic diagram showing an example of a circuit board 40 of a heat source unit 1 on which this drive circuit 30 is mounted.

[0057] As shown in Fig. 5, the drive circuit 30 has a switching power supply circuit 33 that steps down an AC power supply 35, which is a commercial power supply, to a predetermined DC voltage. The load R corresponds to various electronic devices of the heat source unit 1 (for example, the power relay of the compressor 11, the power relay of the four-way valve 12, the first expansion valve E1, the second expansion valve E2, the first on-off valve V1, and the second on-off valve V2) that are driven by the same drive voltage as the DC solenoid valves, and for example, the load R is the solenoid 63 of the first on-off valve V1 or the second on-off valve V2 (described later using Fig. 9). Here, the voltage of the AC power supply 35 is, for example, 230 V, and the drive voltage of the load R is, for example, 12 V.

[0058] The drive circuit 30 includes a first switch 31 arranged between an AC power supply 35 and a switching power supply circuit 33, a second switch 32 arranged between the switching power supply circuit and a load R, and a resistive element 34 connected in parallel with the first switch 31.

[0059] The switching power supply circuit 33 is a DC power supply circuit that converts the AC voltage (230 V) of the AC power supply 35 into a predetermined DC voltage (12 V). The first switch 31 is a power relay that switches whether or not the power supply voltage is input to the switching power supply circuit 33 via a resistive element 34. The second switch 32 is a relay that switches on and off the supply of current to the load R. The resistive element 34 is used to prevent inrush current from flowing from the AC power supply 35 toward the switching power supply circuit 33 when the first switch 31 is turned off (disconnected) at the start of the switching power supply circuit 33.

[0060] 6, the circuit board 40 includes an AC power input unit 41 (including the first switch 31 and the resistive element 34 in FIG. 5) connected to an AC power supply 35, and a rectifier circuit unit 42 and a DC-DC conversion circuit unit 43 that constitute the switching power supply circuit 33. The DC-DC conversion circuit unit 43 is a step-down circuit such as a chopper circuit that includes a capacitor, a coil, a relay, etc.

[0061] The circuit board 40 further includes a control device 90 (CPU 91) and connector components connected to each device of the heat source unit 1, such as a first expansion valve connector 71 connected to the first expansion valve E1, a first on-off valve connector 72 connected to the first on-off valve V1, a second expansion valve connector 73 connected to the second expansion valve E2, a second on-off valve connector 74 connected to the second on-off valve V2, and a four-way valve connector 75 connected to the four-way valve 12.

[0062] The various connectors 71 to 75 are connected to the switching power supply circuit 33 via wiring patterns on the circuit board 40. For example, FIG. 7 shows a schematic example of a wiring pattern connecting the switching power supply circuit 33 to the first expansion valve connector 71 and the first on-off valve connector 72. The gray wiring pattern P1 in the figure is formed, for example, on a wiring layer on the front side of the circuit board 40, and connects the switching power supply circuit 33 to the positive electrode of the first expansion valve connector 71 and the positive electrode of the first on-off valve connector 72. On the other hand, the black wiring pattern P2 is formed, for example, on a wiring layer on the back side of the circuit board 40, and connects the switching power supply circuit 33 to the negative electrode of the first expansion valve connector 71 and the negative electrode of the first on-off valve connector 72.

[0063] 7, the wiring pattern P1 has a common wiring portion P10 common to the first expansion valve connector 71 and the first on-off valve connector 72 connected to the switching power supply circuit 33, and two branch wiring portions P11, P12 branching from the common wiring portion P10 to the first expansion valve connector 71 and the first on-off valve connector 72. Similarly, the wiring pattern P2 has a common wiring portion P20 common to the first expansion valve connector 71 and the first on-off valve connector 72 connected to the switching power supply circuit 33, and two branch wiring portions P21, P22 branching from the common wiring portion P20 to the first expansion valve connector 71 and the first on-off valve connector 72. The common wiring portions P10, P20 correspond to the "first common wiring portion" in the present invention, and the branch wiring portions P11, P12, P21, P22 correspond to the "first branch wiring portion" in the present invention.

[0064] Here, if the first on-off valve V1 is a normally-open DC solenoid valve that closes when energized, maintaining the first on-off valve V1 in its closed state typically requires continuous energization of the first on-off valve V1. To drive the first expansion valve E1 in this state, the drive current for the first on-off valve V1 and the drive current for the first expansion valve E1 simultaneously flow through the wiring patterns P1 and P2. Therefore, the common wiring portions P10 and P20 of the wiring patterns P1 and P2 are formed with wide patterns to prevent breakage due to Joule heat generated when the drive current is applied. In particular, the larger the drive current, the wider the pattern width of the common wiring portions P10 and P20 must be. Therefore, the spacing between the wiring patterns P1 and P2 (the width of the non-pattern-forming region between the wiring patterns P1 and P2 and the adjacent wiring patterns) must also be wide. This same problem occurs with the wiring patterns connecting the switching power supply circuit 33 to the connector 73 for the second expansion valve and the connector 74 for the second on-off valve, and as a result, it is unavoidable to increase the size of the circuit board 40 in order to secure an area for forming these wiring patterns.

[0065] Therefore, in this embodiment, the control device 90 controls the drive of the first expansion valve E1 and the first on-off valve V1 so that they are not energized simultaneously. This prevents, for example, a drive current that would simultaneously drive the first expansion valve E1 and the first on-off valve V1 from flowing through the wiring patterns P1 and P2. The control device 90 also controls the drive of the second expansion valve E2 and the second on-off valve V2 so that they are not energized simultaneously. This prevents, for example, a drive current that would simultaneously drive the second expansion valve E2 and the second on-off valve V2 from flowing through the wiring patterns P3 and P4 (described later using FIG. 8(B)).

[0066] As a result, the patterns of the common wiring portions P10, P20 of these wiring patterns P1, P2 can be formed with approximately the same width as the pattern width of the branch wiring portions P11, P12, P21, P22 (for example, a width that is at least one time but less than two times the pattern width of the branch wiring portions), as shown in Figure 8(A), so the area required to form these wiring patterns P1, P2 can be reduced. This prevents the circuit board 40 from becoming larger, so the circuit board 40 can be made more compact than the structure shown in Figure 7. The same applies to each of the wiring patterns P3, P4, and details will be described later.

[0067] Here, "substantially the same" width refers not only to the pattern width of the common wiring portion being the same as the pattern width of the branch wiring portion, but also to widths slightly wider and narrower than the pattern width of the branch wiring portion. In other words, the width of the wiring pattern is set according to the magnitude of the current flowing through the wiring pattern, and therefore the pattern width of the common wiring portion is set according to the maximum current value (e.g., 1 A) flowing through the first expansion valve E1 and the maximum current value (e.g., 1 A) flowing through the first on-off valve V1. In this case, the pattern width of the common wiring portion and each branch wiring portion is appropriate, for example, 2.5 mm or more, taking into account the heat generation temperature when the maximum current value flows. In this embodiment, it is set to 2.8 mm. Note that even if current flows through either the expansion valve or the on-off valve, the current always flows through the pattern of the common wiring portion. Therefore, considering Joule heat, the pattern width of the common wiring portion is preferably at least one time the pattern width of the branch wiring portion. Furthermore, to avoid an increase in the size of the circuit board 40, it is more preferable that the pattern width of the common wiring portion be less than twice the pattern width of the branch wiring portion.

[0068] The same effect can be obtained with respect to the wiring patterns connecting the switching power supply circuit 33 to the second expansion valve connector 73 and the second on-off valve connector 74. As shown in Fig. 8(B), the wiring pattern P3 shown in gray is formed, for example, in a wiring layer on the front side of the circuit board 40, and connects between the switching power supply circuit 33 and the positive electrode of the second expansion valve connector 73 and the positive electrode of the second on-off valve connector 74. On the other hand, the wiring pattern P4 shown in black is formed, for example, in a wiring layer on the back side of the circuit board 40, and connects between the switching power supply circuit 33 and the negative electrode of the second expansion valve connector 73 and the negative electrode of the second on-off valve connector 74.

[0069] 8(B), the wiring pattern P3 has a common wiring section P30 common to the second expansion valve connector 73 and the second on-off valve connector 74 connected to the switching power supply circuit 33, and two branch wiring sections P33, P34 branching from the common wiring section P30 to the second expansion valve connector 73 and the second on-off valve connector 74. Similarly, the wiring pattern P4 has a common wiring section P40 common to the second expansion valve connector 73 and the second on-off valve connector 74 connected to the switching power supply circuit 33, and two branch wiring sections P43, P44 branching from the common wiring section P40 to the second expansion valve connector 73 and the second on-off valve connector 74. In this case, too, the patterns of the common wiring portions P30, P40 of each wiring pattern P3, P4 can be formed with approximately the same width as the pattern width of the branch wiring portions P33, P34, P43, P44 (for example, a width that is at least one time but less than two times the width of the pattern of the branch wiring portion), thereby reducing the area required to form these wiring patterns P3, P4. Note that the common wiring portions P30, P40 correspond to the "second common wiring portion" in this invention, and the branch wiring portions P33, P34, P43, P44 correspond to the "second branch wiring portion" in this invention.

[0070] As described above, the pattern width of the common wiring portion of the wiring pattern connecting between the switching power supply circuit 33 and each of the valve connectors 71 to 74 can be made substantially the same as the pattern width of the branch wiring portion, so that the common wiring portion of each wiring pattern can be extended to a position near each of the valve connectors 71 to 74. This allows each of the valve connectors 71 to 74 to be arranged close to each other, thereby realizing a reduction in the area in which each of these connectors 71 to 74 is mounted, and further preventing the circuit board 40 from becoming larger.

[0071] In this embodiment, in order to prevent two or more of the first expansion valve E1, the second expansion valve E2, the first on-off valve V1, and the second on-off valve V2 from being energized simultaneously as described above, the first on-off valve V1 and the second on-off valve V2 are DC solenoid valves that close when energized and have a valve structure that maintains a closed state even when de-energized after the pressure difference between the inlet and outlet sides of the refrigerant reaches a predetermined value or more when energized. This allows, for example, the first expansion valve E1 to be driven while maintaining a closed state without energizing the first on-off valve V1, even if the first expansion valve E1 and the first on-off valve V1 are not energized simultaneously.

[0072] The following describes the configurations of the first on-off valve V1 and the second on-off valve V2, which are DC solenoid valves having such a structure. Figure 9 is a schematic side cross-sectional view showing the structure of the first on-off valve V1, where (A) shows the open state (state when not energized) and (B) shows the closed state (state when energized). Note that the second on-off valve V2 is configured in the same way as the first on-off valve V1, so only the first on-off valve V1 will be described here.

[0073] The first on-off valve V1 has a casing 60 having a valve chamber 61, a plunger 62 arranged inside the casing 60, a solenoid 63 that moves the plunger 62 to a closed position (operating position) relative to the casing 60, a return spring 64 that returns the plunger 62 to an open position (non-operating position), and a valve seat 66.

[0074] The casing 60 further has a first refrigerant inlet / outlet 61a connected to the four-way valve 12 (gas pipe G) and a second refrigerant inlet / outlet 61b connected to the first indoor heat exchanger 21, and the valve chamber 60 is formed inside the casing 60 so as to communicate with the first refrigerant inlet / outlet 61a and the second refrigerant inlet / outlet 61b. The valve chamber 61, the first refrigerant inlet / outlet 61a, and the second refrigerant inlet / outlet 61b form a part of the first gas branch pipe G1 of the refrigerant circuit 10.

[0075] In the case of the second on-off valve V2, the first refrigerant inlet / outlet 61a is connected to the four-way valve 12 (gas pipe G), and the second refrigerant inlet / outlet 61b is connected to the second indoor heat exchanger 22, and the valve chamber 61, the first refrigerant inlet / outlet 61a and the second refrigerant inlet / outlet 61b form part of the second gas branch pipe G2 of the refrigerant circuit 10.

[0076] The plunger 62 is a shaft-shaped member made of a soft magnetic material such as steel. A shaft portion 62a of the plunger 62 is disposed inside the casing 60 so as to be slidable along the inner peripheral surface of a seal ring 65 supported by the casing 60. An expanded diameter portion 62b is provided at one end of the plunger 62 on the valve chamber 61 side, facing a valve seat 66 formed around the second refrigerant inlet / outlet 61b. The expanded diameter portion 62b has a diameter larger than that of the shaft portion 62a and is formed, for example, in a disk shape.

[0077] The solenoid 63 is a coil wound around the plunger 62, and is disposed inside the casing 60. When the solenoid 63 is excited by passing a DC current through it, it generates an electromagnetic force that moves the plunger 62 to a valve-closed position (see FIG. 9(B)) where the expanded diameter portion 62a of the plunger 62 abuts against the valve seat 66.

[0078] The return spring 64 is a tension coil spring provided between the expanded diameter portion 62a of the plunger 62 and the upper surface of the valve chamber 61, and biases the plunger 62 toward the valve open position (see FIG. 9(A)).

[0079] When the solenoid 63 is de-energized, the first on-off valve V1 configured as described above is in an open state in which the first refrigerant inlet / outlet 61a and the second refrigerant inlet / outlet 61b are communicated with each other by the biasing force of the return spring 64, which holds the plunger 62 in the open position shown in Figure 9(A). This opens the first gas branch pipe G1, allowing refrigerant to flow in both directions between the four-way valve 12 and the first indoor heat exchanger 21. In this embodiment, when the first indoor unit 2A performs cooling operation, the first on-off valve V1 is de-energized to allow refrigerant to flow from the first indoor heat exchanger 21 to the four-way valve 12. When the first indoor unit 2A performs heating operation, the first on-off valve V1 is de-energized to allow refrigerant to flow from the four-way valve 12 to the first indoor heat exchanger 21.

[0080] On the other hand, when the solenoid 63 is energized, the plunger 62 moves toward the valve chamber 61 against the biasing force of the return spring 64, and the first on-off valve V1 assumes a closed valve position in which the expanded diameter portion 62b of the plunger 62 abuts against the valve seat 66, as shown in Figure 9(B), thereby entering a closed valve state in which communication between the first refrigerant inlet / outlet 61a and the second refrigerant inlet / outlet 61b is blocked. This blocks the flow of refrigerant in both directions between the four-way valve 12 and the first indoor heat exchanger 21. In this embodiment, when the second indoor unit 2B is performing hot water supply operation, the first on-off valve V1 is energized to block the flow of refrigerant from the four-way valve 12 toward the first indoor heat exchanger 21.

[0081] When the first on-off valve V1 is closed, a pressure difference occurs between the first gas branch pipe G1 on the first refrigerant inlet / outlet side 61a and the first gas branch pipe G1 on the second refrigerant inlet / outlet side. More specifically, the pressure of the refrigerant in the first refrigerant inlet / outlet 61a connected to port a of the four-way valve 12 via the gas pipe G and in the valve chamber 61 communicating therewith becomes higher than the pressure of the refrigerant in the second refrigerant inlet / outlet 61b connected to the first indoor heat exchanger 21. The pressure in the valve chamber 61 acts in a direction pressing the expanded diameter portion 62b of the plunger 62 against the valve seat 66. Then, the force pressing the expanded diameter portion 62b against the valve seat 66 due to the refrigerant pressure becomes stronger than the biasing force of the return spring 64. Once the pressure difference exceeds the pressure corresponding to the biasing force of the return spring 64 (maximum operating pressure), the first on-off valve V1 remains closed even when the solenoid 63 is de-energized.

[0082] As described above, when the heat pump device 100 performs hot water supply operation in the second indoor unit 2B, the first on-off valve V1 can be maintained in a closed state even when not energized after the refrigerant pressure difference between the first refrigerant inlet / outlet 61a and the second refrigerant inlet / outlet 61b reaches a pressure equal to or greater than a predetermined value corresponding to the biasing force of the return spring 64. This eliminates the need to constantly energize the solenoid 63 when the first on-off valve V1 is closed, thereby reducing the power required to drive the first on-off valve V1.

[0083] When the first on-off valve V1 is in the closed state shown in Figure 9(B) and one of the operating indoor units is stopped or the other indoor unit is started, for example, when the operation of the compressor 11 is stopped to stop hot water supply operation in the second indoor unit 2B or to switch from hot water supply operation to heating operation in the first indoor unit 2A, the pressure of the refrigerant in the valve chamber 61 of the first on-off valve V1 decreases, and when this pressure becomes smaller than a predetermined value corresponding to the biasing force of the return spring 64, the biasing force of the return spring 64 overcomes the pressure of the refrigerant in the valve chamber 61, causing the plunger 62 to move to the inoperative position shown in Figure 9(A), and the first on-off valve V1 returns to the open state.

[0084] [Method for controlling a heat pump device] Next, a control method for the heat pump apparatus 100 including the first on-off valve V1 and the second on-off valve V2 configured as DC solenoid valves as described above will be described. Here, a processing procedure by the control device 90 when the heat pump apparatus 100 starts heating operation in the first indoor unit 2A will be described.

[0085] Figure 10 is a diagram showing the changes over time in the operating state of each part of the heat source unit 1 when heating operation is started in the first indoor unit 2A, where (A) shows the rotation speed of the compressor 11, (B) shows the rotation speed of the outdoor fan 13F, (C) shows the communication state of the four-way valve 12, (D) shows the opening degree of the first expansion valve E1 (operating side) and the second expansion valve E2 (stopped side), and (E) shows the opening and closing state of the first opening / closing valve V1 (operating side) and the second opening / closing valve V2 (stopped side).

[0086] When a user operates a controller (not shown) to instruct the first indoor unit 2A to start heating operation, the heat pump apparatus 100 receives the operation instruction from the user and starts the heating operation of the first indoor unit 2A (time T0). First, at time T1, the control device 90 starts the outdoor fan 13F at the startup control rotation speed Rf1 and energizes the operating expansion valve (hereinafter also referred to as the first expansion valve E1) located in the refrigerant circuit 10 including the operating first indoor unit 2A to change the valve opening from fully closed to fully open. Here, the first expansion valve E1 is energized only when the opening is changed and is de-energized when the number of pulses corresponding to the target opening is reached. After performing startup control of the outdoor fan 13F at the rotation speed Rf1 for a predetermined time (a predetermined time between times T2 and T3 in the example shown in FIG. 10(B)), the control device 90 increases the rotation speed of the indoor fan 13F from the startup control to the normal control rotation speed Rf2.

[0087] Subsequently, at time T2, the control device 90 starts startup control to drive the compressor 11 at the rotation speed Rc1 for a predetermined time. This startup control is a process for stably circulating the refrigerant in the refrigerant circuit 10. The predetermined time may be, for example, the time required for the pressure (discharge pressure and suction pressure) in the refrigerant circuit 10 to reach a constant value, and in this embodiment, it is the period from time T2 to time T3 (for example, 1 minute).

[0088] At time T2, the control device 90 energizes the four-way valve 12 to switch it to the state shown by the dashed line in FIG. 1 , i.e., State 1, in which ports a and d are connected and ports c and d are connected, causing the refrigerant circuit 10 to operate in a heating cycle. Furthermore, the control device 90 energizes the first expansion valve E1 to control its opening to a relatively small opening corresponding to the initial pulse P1, and energizes the expansion valve (hereinafter also referred to as the second expansion valve E2) located in the refrigerant circuit including the stopped second indoor unit 2B until it changes from fully closed to fully open. Here, the second expansion valve E2 is energized only when its opening is changed, and is de-energized when the number of pulses corresponding to the target opening is reached. Note that in FIG. 10, State 2 refers to the state in which the four-way valve 12 is in the state shown by the solid line in FIG. 1 , i.e., State 2, in which ports a and b are connected and ports c and d are connected, causing the refrigerant circuit 10 to operate in a cooling cycle.

[0089] Next, at time T3 after the start-up control of the compressor 11 is completed, the control device 90 executes control (rotation speed pulse control) to energize the first expansion valve E1, which is the operating expansion valve, and adjust the opening from P1 to P2 so that the discharge temperature of the compressor 11 becomes the target discharge temperature. As described above, the opening of the first expansion valve E1 is adjusted so that the discharge temperature becomes the target discharge temperature. Therefore, the control device 90 starts energizing the first expansion valve E1 at time T3 and stops energizing it when the opening becomes P2 (just before time T4). During this time, the control device 90 energizes the first expansion valve E1 multiple times depending on the temperature difference between the detected discharge temperature and the target discharge temperature. While adjusting the opening of the first expansion valve E1, the control device 90 increases the rotation speed of the compressor 11 to Rc2 to follow the change in the state of the refrigerant corresponding to the change in the opening of the first expansion valve E1.

[0090] Meanwhile, the control device 90 energizes the solenoid 63 of the second on-off valve V2 only for a predetermined time within the period from time T2, when the startup control of the compressor 11 is initiated, to time T3, when the startup control is terminated. The second on-off valve V2 is a stop-side on-off valve disposed in a refrigerant circuit including the second indoor unit 2B, which is currently in operation. As shown in FIG. 10, the control device 90 energizes the four-way valve 12 and the first expansion valve E1 at time T2, and then energizes the second on-off valve V2, for example, 5 seconds after time T2. The control device 90 then deenergizes the second on-off valve V2 after a predetermined time (hereinafter also referred to as the second predetermined time) has elapsed since energization began. In this manner, the control device 90 energizes the second on-off valve V2 for the second predetermined time, thereby switching the second on-off valve V2 from an open state to a closed state. Here, the second predetermined time is not particularly limited as long as it is equal to or longer than the time required for the valve chamber 61 (see FIG. 9) of the second on-off valve V2 to reach the maximum operating pressure of the second on-off valve V2. In this embodiment, the second predetermined time is 50 seconds. As a result, the valve chamber 61 reaches the maximum operating pressure or more, so the second on-off valve V2 remains closed (see FIG. 9(B)) even after the second on-off valve V2 is de-energized.

[0091] Furthermore, when the user operates the controller at time T4 to instruct the first indoor unit 2A to stop heating operation and stop the compressor 11, the outdoor fan 13F is stopped at a subsequent time T5, and the first expansion valve E1 is controlled to be fully open at a further time T6. The compressor 11 is stopped at time T4 and then the outdoor fan 13F is stopped at time T5 to suppress the generation of refrigerant flow noise caused by a sudden change in the state of the refrigerant when the compressor 11 and the outdoor fan 13F are stopped simultaneously. The outdoor fan 13F is stopped at time T5 and then the first expansion valve E1 is fully opened at time T6 to suppress the increase in refrigerant noise flowing through the first expansion valve E1 caused by the large pressure difference across the first expansion valve E1 immediately after the compressor 11 or the outdoor fan 13F is stopped. Furthermore, the second on-off valve V2, which was closed, opens when the pressure in the valve chamber 61 of the second on-off valve V2 drops below the maximum operating pressure after the compressor 11 is stopped at time T4, and changes from closed to open, for example, between time T5 when the outdoor fan 13F is stopped and time T6 when the first expansion valve E1 is fully open.

[0092] As described above, when the first indoor unit 2A is operated from a stopped state of the compressor 11 and the second indoor unit 2B is stopped, the control device 90 closes the second on-off valve V2 within the execution period of startup control that drives the compressor 11 at a constant rotation speed for a predetermined time when the compressor 11 is started. As a result, the power supply to the second on-off valve V2 ends before rotation speed pulse control of the first expansion valve E1 begins, and therefore the first expansion valve E1 and second on-off valve V2 are not driven simultaneously.

[0093] Furthermore, by performing the process of closing the second on-off valve V2 during the execution period of the startup control of the compressor 11, the time until the heating operation control (rotation speed pulse control of the first expansion valve E1) can be shortened.

[0094] Furthermore, in this embodiment, the supply of current to the second on-off valve V2 begins after the start-up control of the compressor 11 has begun, and the supply of current to the second on-off valve V2 is terminated before the start-up control of the compressor 11 has ended. Therefore, it is possible to start heating operation control promptly after the end of the start-up control without waiting for the closing process of the second on-off valve V2.

[0095] The above description has been given taking the case where the heat pump device 100 performs heating operation as an example, but a similar processing procedure is also adopted during hot water supply operation. In this case, the first on-off valve V1 is switched from an open state to a closed state within the start-up control period of the compressor 11. [Explanation of symbols]

[0096] 1...Heat source unit 2A, 2B...Indoor unit 10...Refrigerant circuit 11...Compressor 12...Four-way valve 13...Outdoor heat exchanger 13F...Outdoor fan 21...No. 1 indoor heat exchanger 22…Second indoor heat exchanger 30...Drive circuit 33...Switching power supply circuit (DC power supply circuit) 40...Circuit board 50…Water circuit 71...First expansion valve connector 72... Connector for first on-off valve 73...Second expansion valve connector 74...Connector for second on-off valve 90...Control device 100...Heat pump equipment E1...First expansion valve E2: Second expansion valve V1: First shut-off valve V2: Second shut-off valve

Claims

1. a first indoor unit having a first indoor heat exchanger; a second indoor unit having a second indoor heat exchanger; a heat source unit having a compressor, an outdoor heat exchanger, a first liquid pipe connecting the outdoor heat exchanger and the first indoor heat exchanger, a second liquid pipe connecting the outdoor heat exchanger and the second indoor heat exchanger, a first gas pipe connecting the compressor and the first indoor heat exchanger, a second gas pipe connecting the compressor and the second indoor heat exchanger, a first expansion valve arranged in the first liquid pipe, a second expansion valve arranged in the second liquid pipe, a first on-off valve arranged in the first gas pipe, a second on-off valve arranged in the second gas pipe, and a control device that controls the compressor, the first expansion valve, the second expansion valve, the first on-off valve, and the second on-off valve, respectively; Equipped with the first expansion valve and the second expansion valve are electronic expansion valves whose opening degrees are adjusted by passing a direct current therethrough; the first on-off valve and the second on-off valve are direct-acting solenoid valves that open and close when a direct current is passed through them, the control device has a circuit board on which a DC power supply circuit, a first expansion valve connector connected to the first expansion valve, a second expansion valve connector connected to the second expansion valve, a first on-off valve connector connected to the first on-off valve, and a second on-off valve connector connected to the second on-off valve are mounted, and on which wiring patterns are provided to connect the DC power supply circuit and the first expansion valve connector, the DC power supply circuit and the second expansion valve connector, the DC power supply circuit and the first on-off valve connector, and the DC power supply circuit and the second on-off valve connector, The wiring pattern includes a first common wiring portion common to the first expansion valve connector and the first on-off valve connector, and a first branch wiring portion branching from the first common wiring portion to the first expansion valve connector and the first on-off valve connector. Heat pump equipment.

2. The heat pump device according to claim 1, The first on-off valve and the second on-off valve are solenoid valves that are closed when energized, and have a valve structure that maintains the closed state even when de-energized after the pressure difference between the inlet side and the outlet side of the refrigerant reaches a predetermined value or more when energized. Heat pump equipment.

3. The heat pump device according to claim 2, The wiring pattern further includes a second common wiring portion common to the second expansion valve connector and the second on-off valve connector, and a second branch wiring portion branching from the second common wiring portion to the second expansion valve connector and the second on-off valve connector. Heat pump equipment.

4. The heat pump device according to claim 3, The control device does not simultaneously energize two or more of the first expansion valve, the second expansion valve, the first on-off valve, and the second on-off valve. Heat pump equipment.

5. The heat pump device according to claim 3, The first expansion valve connector and the second expansion valve connector are disposed adjacent to the first on-off valve connector and the second on-off valve connector. Heat pump equipment.

6. The heat pump device according to claim 3, The width of the wiring in the common wiring section is approximately the same as the width of the wiring in the branch wiring section. Heat pump equipment.

7. The heat pump device according to claim 1, The DC power supply circuit is a power supply circuit common to the devices that constitute the heat source unit, including the compressor. Heat pump equipment.

8. The heat pump device according to claim 1, The wiring pattern further includes a second common wiring portion common to the second expansion valve connector and the second on-off valve connector, and a second branch wiring portion branching from the second common wiring portion to the second expansion valve connector and the second on-off valve connector. Heat pump equipment.

9. an outdoor unit refrigerant circuit including a compressor, an outdoor heat exchanger, a first liquid pipe connecting the outdoor heat exchanger to a first indoor heat exchanger in a first indoor unit, a second liquid pipe connecting the outdoor heat exchanger to a second indoor heat exchanger in a second indoor unit, a first gas pipe connecting the compressor to the first indoor heat exchanger, a second gas pipe connecting the compressor to the second indoor heat exchanger, a first expansion valve arranged in the first liquid pipe, a second expansion valve arranged in the second liquid pipe, a first on-off valve arranged in the first gas pipe, and a second on-off valve arranged in the second gas pipe; a control device that controls the compressor, the first expansion valve, the second expansion valve, the first on-off valve, and the second on-off valve, the first expansion valve and the second expansion valve are electronic expansion valves whose opening degrees are adjusted by passing a direct current therethrough; the first on-off valve and the second on-off valve are direct-acting solenoid valves that open and close when a direct current is passed through them, the control device has a circuit board on which a DC power supply circuit, a first expansion valve connector connected to the first expansion valve, a second expansion valve connector connected to the second expansion valve, a first on-off valve connector connected to the first on-off valve, and a second on-off valve connector connected to the second on-off valve are mounted, and on which wiring patterns are provided to connect the DC power supply circuit and the first expansion valve connector, the DC power supply circuit and the second expansion valve connector, the DC power supply circuit and the first on-off valve connector, and the DC power supply circuit and the second on-off valve connector, The wiring pattern includes a first common wiring portion common to the first expansion valve connector and the first on-off valve connector, and a first branch wiring portion branching from the first common wiring portion to the first expansion valve connector and the first on-off valve connector. Heat source unit.

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