Heat source unit of refrigeration cycle device, and refrigeration cycle device

Abstract

A heat source unit (2) comprises an electrical component unit (70), a heat-source-side refrigerant main flow path (300), and a first refrigerant sub flow path (46) having a first cooling part (47) for cooling a first part of the electrical component unit (70) and a second part of the electrical component unit (70). The heat-source-side refrigerant main flow path (300) has an accumulator (29), a compressor (21), a heat-source-side heat exchanger (23), and a heat-source-side expansion valve (25). The heat-source-side refrigerant main flow path (300) is connected to a usage-side refrigerant flow path (500) of a usage unit (3a, 3b) and forms a refrigerant circuit (10). The first refrigerant sub flow path (46) branches from a liquid flow path (340) that extends from the heat-source-side heat exchanger (23) of the heat-source-side refrigerant main flow path (300) to the use-side refrigerant flow path (500), the first refrigerant sub flow path (46) causing refrigerant to flow to a gas flow path (310) between the accumulator (29) and the compressor (21) of the heat-source-side refrigerant main flow path (300).

Description

Heat source unit and refrigeration cycle device of a refrigeration cycle device

[0001] Relates to a heat source unit and a refrigeration cycle device of a refrigeration cycle device.

[0002] Conventionally, there is a cooling circuit for cooling an electrical component unit whose one end is connected to a liquid pipe and the other end is connected to the upstream side of an accumulator (Patent Document 1 (Japanese Patent Application Laid-Open No. 2022-146443)).

[0003] In the conventional cooling circuit, in order to suppress the rise in the discharge temperature of the compressor by the R32 refrigerant, it may be necessary to provide a liquid injection circuit, which may complicate the circuit. Also, there is a problem that the cooling capacity may be insufficient when the heat generation amount of the electrical component unit increases.

[0004] The heat source unit of the refrigeration cycle device from the first aspect includes an electrical component unit, a heat source side refrigerant main flow path, and a first refrigerant sub-flow path. The heat source side refrigerant main flow path has an accumulator, a compressor, a heat source side heat exchanger, and a heat source side main expansion mechanism. The heat source side refrigerant main flow path is connected to the utilization side refrigerant flow path of the utilization unit to form a refrigerant circuit. The first refrigerant sub-flow path has a first cooling unit that cools the first part and the second part of the electrical component unit. The first refrigerant sub-flow path branches from a liquid flow path extending from the heat source side heat exchanger of the heat source side refrigerant main flow path to the utilization side refrigerant flow path, and flows the refrigerant through a gas flow path between the accumulator and the compressor of the heat source side refrigerant main flow path.

[0005] In this heat source unit of the refrigeration cycle device, the first refrigerant sub-flow path can be used for cooling the electrical component unit, and can also cool the gas refrigerant sucked into the compressor.

[0006] The heat source unit of the refrigeration cycle device from the second aspect is the heat source unit from the first aspect, and includes a first flow rate adjustment mechanism and a control unit. The first flow rate adjustment mechanism adjusts the flow rate of the refrigerant flowing through the first refrigerant sub-flow path. The control unit controls the opening degree of the first flow rate adjustment mechanism based on the discharge pipe temperature of the compressor.

[0007] In this refrigeration cycle system's heat source unit, when the compressor discharge pipe temperature rises, the opening of the first flow rate adjustment mechanism is increased to cool the gas refrigerant drawn into the compressor, thereby lowering the compressor discharge pipe temperature and protecting the compressor.

[0008] The heat source unit of the refrigeration cycle device in the third perspective is the heat source unit in the second perspective, and the control unit controls the opening degree of the first flow rate adjustment mechanism based on the temperature of the compressor discharge pipe and the temperature of the electrical equipment unit.

[0009] In this refrigeration cycle system's heat source unit, when the compressor discharge pipe temperature rises and the temperature of the electrical components rise, the opening of the first flow rate adjustment mechanism is increased to cool the gas refrigerant drawn into the compressor, thereby lowering the compressor discharge pipe temperature and achieving cooling of the electrical components.

[0010] The heat source unit of the refrigeration cycle device in the fourth view is a heat source unit of either the first view or the third view, and the electrical component unit is enclosed in a housing. The first refrigerant subflow channel cools the housing space inside the housing.

[0011] This heat source unit of the refrigeration cycle system lowers the discharge pipe temperature of the compressor and, compared to cooling electrical components, can cool the housing space containing the electrical components with a smaller amount of cooling.

[0012] The heat source unit of the refrigeration cycle device in the fifth view is a heat source unit according to either the second view or the fourth view, and further comprises a second refrigerant subflow path. The second refrigerant subflow path has a second cooling section and a second flow rate adjustment mechanism. The second cooling section cools the second part of the electrical component unit. The second flow rate adjustment mechanism adjusts the amount of refrigerant flowing to the second cooling section. The second refrigerant subflow path connects the liquid piping on the heat source side heat exchanger side of the heat source side main expansion mechanism to the liquid piping on the opposite side of the heat source side heat exchanger side of the heat source side main expansion mechanism. The first refrigerant subflow path branches off from a position on the user side refrigerant circuit side rather than a position on the opposite side of the heat source side heat exchanger side of the heat source side main expansion mechanism to which the second refrigerant subflow path is connected.

[0013] In the heat source unit of this refrigeration cycle system, the first refrigerant subflow channel branches off from a position in the liquid flow channel that is closer to the user-side refrigerant circuit than the second refrigerant subflow channel, thereby ensuring a sufficient amount of refrigerant for cooling in the second refrigerant subflow channel.

[0014] The heat source unit of the refrigeration cycle device according to the sixth aspect is the heat source unit according to the fifth aspect, further comprising a fourth refrigerant sub-flow path. The fourth refrigerant sub-flow path has a fourth cooling section and a fourth flow rate adjustment mechanism. The fourth cooling section cools the first part of the electrical component unit. The fourth flow rate adjustment mechanism expands the refrigerant flowing through the fourth cooling section. The fourth refrigerant sub-flow path branches off from the liquid flow path extending from the heat source side heat exchanger to the utilization side refrigerant flow path of the heat source side refrigerant main flow path, and flows refrigerant into the gas flow path on the suction side of the compressor of the heat source side refrigerant main flow path.

[0015] In this refrigeration cycle unit's heat source unit, when operating with the heat source-side heat exchanger, which cools the refrigerant with outside air, as the condenser, the high-temperature, high-pressure liquid refrigerant condensed in the heat source-side heat exchanger is expanded by the fourth flow rate adjustment mechanism of the fourth refrigerant sub-flow path to lower its temperature. This two-phase gaseous refrigerant then absorbs heat from the electrical components unit and evaporates, returning to the gas flow path on the compressor's intake side. This allows for stronger cooling of the electrical components unit than in conventional systems where high-temperature, high-pressure liquid refrigerant was used to cool the electrical components unit.

[0016] The heat source unit of the refrigeration cycle device in the seventh aspect is the heat source unit of the sixth aspect, wherein the heat source side refrigerant main flow path further comprises a subcooled heat exchanger. The subcooled heat exchanger is located in a liquid flow path extending from the heat source side heat exchanger to the utilization side refrigerant flow path. The heat source unit further comprises a third refrigerant subflow path. The third refrigerant subflow path branches off from the liquid flow path. The third refrigerant subflow path has a third flow rate adjustment mechanism that expands the refrigerant flowing inside it. The third refrigerant subflow path causes heat exchange between the refrigerant that has passed through the third flow rate adjustment mechanism and the refrigerant flowing in the liquid flow path of the heat source side refrigerant main flow path in the subcooled heat exchanger. The third refrigerant subflow path flows the refrigerant after heat exchange into the gas flow path on the suction side of the compressor of the heat source side refrigerant main flow path.

[0017] In the heat source unit of this refrigeration cycle system, when the heat source side heat exchanger, which cools the refrigerant with outside air, is used as a condenser, the high-temperature, high-pressure liquid refrigerant condensed in the heat source side heat exchanger is expanded by the third flow path adjustment mechanism of the third refrigerant sub-flow path to lower its temperature. This lowered refrigerant then exchanges heat with the high-temperature, high-pressure liquid refrigerant, thereby cooling the high-temperature, high-pressure liquid refrigerant condensed in the heat source side heat exchanger.

[0018] The heat source unit of the refrigeration cycle device in the eighth aspect is a heat source unit of either the sixth or seventh aspect, and the control unit controls the opening degree of the second flow rate adjustment mechanism or the fourth flow rate adjustment mechanism based on the temperature of the electrical component unit.

[0019] In this refrigeration cycle system's heat source unit, the temperature or amount of refrigerant can be adjusted according to the temperature of the electrical components unit by controlling the opening degree of the second flow rate adjustment mechanism or the fourth flow rate adjustment mechanism based on the temperature of the electrical components unit, thereby cooling the electrical components unit.

[0020] The heat source unit of the refrigeration cycle device in the ninth aspect is a heat source unit of any of the sixth to eighth aspects, and the electrical component unit includes a first electrical component and a second electrical component. The fourth refrigerant subflow channel cools the first electrical component.

[0021] In this refrigeration cycle system's heat source unit, the fourth refrigerant sub-flow channel can cool specific electrical components.

[0022] The heat source unit of the refrigeration cycle device in the tenth perspective is the heat source unit in the ninth perspective, and the amount of heat generated by the first electrical component is greater than the amount of heat generated by the second electrical component.

[0023] In this refrigeration cycle system's heat source unit, the first electrical component, which generates a large amount of heat, can be cooled by a fourth refrigerant sub-flow channel that lowers the temperature of the high-temperature, high-pressure liquid refrigerant.

[0024] The heat source unit of the refrigeration cycle device in the 11th aspect is a heat source unit in either the 6th or 10th aspect, wherein the fourth refrigerant subflow path branches off from a position on the user-side refrigerant flow path side rather than from a position on the opposite side of the heat source-side heat exchanger of the heat source-side main expansion mechanism to which the second refrigerant subflow path is connected, in the liquid flow path extending from the heat source-side heat exchanger of the heat source-side refrigerant main flow path to the user-side refrigerant flow path.

[0025] In the heat source unit of this refrigeration cycle system, the fourth refrigerant subflow channel branches off from the liquid flow channel at a position closer to the utilization-side refrigerant flow channel than the second refrigerant subflow channel, thereby ensuring a sufficient amount of refrigerant for cooling in the second refrigerant subflow channel.

[0026] The refrigeration cycle device according to the twelfth aspect comprises a heat source unit described in any of the first or eleventh aspects, and one or more utilization units. The one or more utilization units are connected to the heat source unit.

[0027] In this refrigeration cycle system, the first refrigerant sub-flow channel can be used to cool the electrical components unit, and it can also be used to cool the gaseous refrigerant drawn into the compressor.

[0028] This is a schematic diagram of the refrigeration cycle device according to this embodiment. This is a schematic external perspective view showing the arrangement of the heat source side control unit in the heat source unit. This is a schematic plan view of the interior of the heat source side control unit. This is a schematic front view of the front portion of the interior of the heat source side control unit. This is a schematic rear view of the rear portion of the interior of the heat source side control unit.

[0029] (1) Diagram 1 of the refrigeration cycle device shows a schematic diagram of the refrigeration cycle device 1.

[0030] The refrigeration cycle device 1 is a device used for cooling and heating rooms in buildings, etc., by operating a vapor compression type refrigeration cycle. The refrigeration cycle device 1 mainly comprises a heat source unit 2, utilization units 3a and 3b, and liquid-side refrigerant connecting pipes 5 and gas-side refrigerant connecting pipes 6 that connect the heat source unit 2 and the utilization units 3a and 3b. The refrigerant circuit 10 of the refrigeration cycle device 1 is configured by connecting the heat source unit 2, the utilization units 3a and 3b, and the liquid-side refrigerant connecting pipes 5 and gas-side refrigerant connecting pipes 6.

[0031] In this embodiment, the refrigerant circuit 10 is filled with any refrigerant, such as R32.

[0032] (1-1) Utilization Units Utilization units 3a and 3b are installed in the ceiling of a room in a building, etc., by embedding or suspending them, or by wall-mounting them on the walls of the room. Utilization units 3a and 3b are connected to the heat source unit 2 via the liquid-side refrigerant connecting pipe 5 and the gas-side refrigerant connecting pipe 6, and constitute a part of the refrigerant circuit 10. Utilization units 3a and 3b have a utilization-side refrigerant flow path 500 that is connected to the heat source-side refrigerant main flow path 100 to form the refrigerant circuit 10.

[0033] In this embodiment, the refrigeration cycle device 1 has a plurality of (in this case, two) utilization units 3a and 3b connected in parallel to each other in the refrigerant circuit 10.

[0034] Next, the configurations of user units 3a and 3b will be described. Since user units 3a and 3b have the same configuration, only the configuration of user unit 3a will be described here. For the configuration of user unit 3b, the subscript "b" will be used instead of the subscript "a" used to indicate each part of user unit 3a, and the description of each part will be omitted.

[0035] The utilization unit 3a mainly comprises a utilization-side expansion valve 51a, a utilization-side heat exchanger 52a, a utilization-side fan 55a, and a utilization-side control unit 75a. The utilization unit 3a also includes a utilization liquid refrigerant pipe 53a connecting the liquid side end of the utilization heat exchanger 52a to the liquid refrigerant connecting pipe 5, and a utilization gas refrigerant pipe 54a connecting the gas side end of the utilization heat exchanger 52a to the gas refrigerant connecting pipe 6.

[0036] The user-side heat exchanger 52a is, for example, a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes and numerous fins. During cooling operation, the user-side heat exchanger 52a functions as a refrigerant evaporator to cool the indoor air, and during heating operation, it functions as a refrigerant radiator or condenser to heat the indoor air. A gas-side refrigerant connecting pipe 6 is connected to the gas side of the user-side heat exchanger 52a.

[0037] The user-side expansion valve 51a is configured as an electronically controlled expansion valve with adjustable valve opening. The user-side expansion valve 51a is installed in the refrigerant flow path between the user-side heat exchanger 52a and the liquid-side refrigerant connecting pipe 5.

[0038] The utilization unit 3a has a utilization-side fan 55a that draws in indoor air into the unit, exchanges heat with the refrigerant in the utilization-side heat exchanger 52a, and then supplies the air to the room as supply air. The utilization-side fan 55a is a centrifugal fan, a multi-blade fan, etc. The utilization-side fan 55a has a utilization-side fan motor 56a.

[0039] The utilization unit 3a is equipped with various sensors. Specifically, the utilization unit 3a is equipped with a utilization-side heat exchanger liquid-side sensor 57a for detecting the temperature Trl of the refrigerant at the liquid-side end of the utilization-side heat exchanger 52a, a utilization-side heat exchanger gas-side sensor 58a for detecting the temperature Trg of the refrigerant at the gas-side end of the utilization-side heat exchanger 52a, and an indoor air sensor 59a for detecting the temperature Tra of the indoor air drawn into the utilization unit 3a.

[0040] The user-side control unit 75a controls the operation of each part that constitutes the user unit 3a. The user-side control unit 75a has a microcomputer, memory, etc., which are provided for controlling the user unit 3a. The user-side control unit 75a can exchange control signals, etc., with the heat source side control unit 70 of the heat source unit 2 or the remote control 9 via the transmission line 8.

[0041] (1-2) Heat source unit The heat source unit 2 is installed outside the building, etc., and is connected to each of the user units 3a and 3b via the liquid side refrigerant connecting pipe 5 and the gas side refrigerant connecting pipe 6, and constitutes part of the refrigerant circuit 10.

[0042] Figure 2 shows a schematic external perspective view illustrating the arrangement of the heat source side control unit 70 in the heat source unit 2. In the following description, unless otherwise specified, "up," "down," "left," "right," "front," and "rear" refer to the direction when viewing the outdoor unit 2 shown in Figure 2 from the front (left-front side of the drawing). In this embodiment, "front" is defined as the direction where the surface without the heat source side heat exchanger 23 or the surface with the smallest portion of the heat source side heat exchanger 23 is located, when viewed from the center of the heat source unit 2 in a plan view. In Figure 2, the heat source side control unit 70, the first cooling section 47 and the second cooling section 67 surrounding it, the heat source side heat exchanger 23, the heat source side fan 24, etc. are mainly shown, and other equipment and piping are omitted.

[0043] The heat source unit 2 mainly includes a heat source unit casing 11, a compressor 21, a four-way switching valve 22, a heat source side heat exchanger 23, a heat source side expansion valve (heat source side main expansion mechanism) 25, an accumulator 29, a liquid side shut-off valve 27, a gas side shut-off valve 28, a first refrigerant sub-flow path 46, a second refrigerant sub-flow path 66, a heat source side fan 24, etc. The four-way switching valve 22 and the suction side of the compressor 21 are connected by a suction refrigerant pipe 31. An accumulator 29 for temporarily storing the refrigerant sucked into the compressor 21 is provided in the suction refrigerant pipe 31. The discharge side of the compressor 21 and the four-way switching valve 22 are connected by a discharge refrigerant pipe 32. The four-way switching valve 22 and the gas side end of the heat source heat exchanger 23 are connected by a first heat source gas refrigerant pipe 33. The liquid side end of the heat source heat exchanger 23 and the liquid refrigerant connecting pipe 5 are connected by a heat source liquid refrigerant pipe 34. A liquid side shut-off valve 27 is provided at the connection portion of the heat source liquid refrigerant pipe 34 and the liquid refrigerant connecting pipe 5. The four-way switching valve 22 and the gas refrigerant connecting pipe 6 are connected by a second heat source gas refrigerant pipe 35. A gas side shut-off valve 28 is provided at the connection portion of the second heat source gas refrigerant pipe 35 and the gas refrigerant connecting pipe 6. The liquid side shut-off valve 27 and the gas side shut-off valve 28 are valves that are manually opened and closed.

[0044] Also, the heat source unit has an accumulator 29, a compressor 21, a heat source side heat exchanger 23, and a heat source side expansion valve 25, and is connected to the use side refrigerant flow paths 500 of the use units 3a and 3b to form a refrigerant circuit 10. The liquid flow path 340 is a flow path that extends from the heat source side heat exchanger 23 of the heat source side refrigerant main flow path 300 to the use side flow path 500. The liquid flow path 340 includes the heat source liquid refrigerant pipe 34. The heat source liquid refrigerant pipe 34 includes a first heat source liquid refrigerant pipe 34a and a second heat source liquid refrigerant pipe 34b. The first heat source liquid refrigerant pipe 34a is a liquid pipe on the heat source side heat exchanger 23 side of the heat source side expansion valve 25. The second heat source liquid refrigerant pipe 34b is a liquid pipe on the side opposite to the heat source side heat exchanger 23 side of the heat source side expansion valve 25. The gas flow path 310 is a flow path on the suction side of the compressor 21 in the heat source side refrigerant main flow path 300. The gas flow path 310 includes the suction refrigerant pipe 31.

[0045] Also, the heat source unit 2 has a first refrigerant sub-flow path 46, a second refrigerant sub-flow path 66, a third refrigerant sub-flow path 41, and a fourth refrigerant sub-flow path 61.

[0046] In this embodiment, the heat source unit 2 is an upward blowing type heat exchange unit that sucks air from the left and right side surfaces and the back surface of the heat source unit casing 11 and blows the air upward from the upper end surface of the heat source unit casing 11.

[0047] The heat source unit casing 11 mainly has a main part 13 and a fan module 12 provided on the main part 13.

[0048] The main part 13 has a pair of mounting legs 18, a bottom frame 15, four support columns 14, a front panel 13a, and net parts 13b, 13c, and 13d. The mounting legs 18 include those provided on the front side and those provided on the rear side, and each extends in the left - right direction. The bottom frame 15 is spanned over each mounting leg 18. Each support column 14 extends vertically from a corner of the bottom frame 15. The front panel 13a spreads between the two front - side support columns 14. The net part 13b is provided so as to spread back - and - forth between the left - side support columns 14. The net part 13c is provided so as to spread left - and - right between the rear - side support columns 14. The net part 13d is provided so as to spread back - and - forth between the right - side support columns 14.

[0049] The bottom frame 15 forms the bottom surface of the heat source unit casing 11, and a heat source - side heat exchanger 23 is provided on the bottom frame 15. Here, the heat source - side heat exchanger 23 is a heat exchanger having a substantially U - shaped planar view facing the back surface and both left and right side surfaces of the heat source unit casing 11.

[0050] Each of the above net parts 13b, 13c, and 13d is provided so as to spread along the outer surface of the heat source - side heat exchanger 23. These net parts 13b, 13c, and 13d substantially form three suction ports on the right side surface, the left side surface, and the back surface of the heat source unit casing 11.

[0051] The front panel 13a has an upper front panel 16 that constitutes the upper part of the front surface of the heat source unit casing 11 and a lower front panel 17 that constitutes the lower part of the front surface of the heat source unit casing 11.

[0052] The fan module 12 is attached to the upper end of each support column 14. The fan module 12 is a roughly rectangular box-shaped body having a front side plate 12a, a left side plate 12b, a back side plate 12c, and a right side plate 12d, and is penetrating in the vertical direction. The fan module 12 houses the heat source side fan 24 inside, forming a flow path for air that flows upward.

[0053] The compressor 21 is, for example, a positive displacement compressor driven by a compressor motor 21a. The compressor motor 21a is driven by power supplied via an inverter device. The operating capacity of the compressor 21 is variable by changing the rotational speed by changing the driving frequency of the compressor motor 21a. The discharge side of the compressor 21 is connected to one of the multiple connection ports of the four-way switching valve 22. In this embodiment, the compressor 21 is mounted on the bottom frame 15.

[0054] The accumulator 29 is a refrigerant container located between the suction side of the compressor 21 and one of the multiple connection ports of the four-way switching valve 22. In this embodiment, the accumulator 29 is mounted on the bottom frame 15.

[0055] The heat source side heat exchanger 23 is, for example, a cross-fin type fin-and-tube heat exchanger composed of heat transfer tubes and numerous fins. The heat source side heat exchanger 23 functions as a refrigerant radiator or condenser during cooling operation and as a refrigerant evaporator during heating operation. One of the multiple connection ports of the four-way switching valve 22 is connected to the gas side of the heat source side heat exchanger 23 via refrigerant piping. The heat source side expansion valve 25 is connected to the liquid side of the heat source side heat exchanger 23 via refrigerant piping.

[0056] The heat source side fan 24 is housed within the fan module 12. The heat source side fan 24 draws in outside air from around the lower part of the heat source unit casing 11, and after heat exchange with the refrigerant in the heat source side heat exchanger 23, it forms an airflow that is discharged upward from an outlet provided on the upper end surface of the fan module 12. This heat source side fan 24 is a propeller fan or the like, driven by a heat source side fan motor 24a consisting of a DC fan motor, and has a variable airflow. In this embodiment, the heat source side fan motor 24a is driven by power supplied via an inverter device.

[0057] The heat source side expansion valve 25 is an electrically operated expansion valve whose valve opening can be adjusted in order to regulate the flow rate of refrigerant flowing through the refrigerant circuit 10. The heat source side expansion valve 25 is installed between the liquid side outlet of the heat source side heat exchanger 23 and the liquid side shut-off valve 29.

[0058] The four-way switching valve 22 has multiple connection ports. The four-way switching valve 22 switches the refrigerant circuit 10 between a cooling operation connection state and a heating operation connection state by switching the connection state of the multiple connection ports. In the cooling operation connection state, the discharge side of the compressor 21 is connected to the heat source side heat exchanger 23, and the suction side of the compressor 21 is connected to the gas side shut-off valve 28. In the heating operation connection state, the discharge side of the compressor 21 is connected to the gas side shut-off valve 28, and the suction side of the compressor 21 is connected to the heat source side heat exchanger 23.

[0059] The liquid-side shut-off valve 27 is a valve provided at the connection port to the liquid-side refrigerant communication pipe 5. The liquid-side shut-off valve 27 is connected via refrigerant piping to the side of the heat source-side expansion valve 25 that is opposite to the heat source-side heat exchanger 23. The gas-side shut-off valve 28 is a valve provided at the connection port to the gas-side refrigerant communication pipe 6. The gas-side shut-off valve 28 is connected via refrigerant piping to one of the multiple connection ports of the four-way switching valve 22.

[0060] The first refrigerant sub-flow channel 46, the second refrigerant sub-flow channel 66, and the fourth refrigerant sub-flow channel 61 are flow channels for cooling electrical components such as heat-generating components, which will be described later, that are located in the heat source side control unit (hereinafter also referred to as the electrical component unit) 70.

[0061] The first refrigerant sub-flow channel 46 has a first cooling section 47 that cools the IPM (Intelligent Power Module, first electrical component) 81a and the IPM (Intelligent Power Module, second electrical component) 82a of the electrical component unit 70. The first refrigerant sub-flow channel 46 branches off from the liquid flow channel 340 that extends from the heat source side heat exchanger 23 of the heat source side refrigerant main flow channel 300 to the user side refrigerant flow channel 500, and flows refrigerant into the gas flow channel 310 between the accumulator 29 and the compressor 21 of the heat source side refrigerant main flow channel 300. The first refrigerant sub-flow channel 46 branches off from a position on the side of the utilization-side refrigerant circuit 500 rather than from the position opposite the heat source-side heat exchanger 23 of the heat source-side expansion valve 25 to which the second refrigerant sub-flow channel 66 is connected (see points G and H in Figure 1). In other words, the first refrigerant sub-flow channel 46 is connected to the portion of the heat source-side liquid refrigerant pipe 34 between the heat source-side expansion valve 25 and the subcooling heat exchanger 45 (see point G in Figure 1). The first refrigerant sub-flow channel 46 is also connected to the suction refrigerant pipe 31 through which the refrigerant drawn into the compressor 21 flows. Furthermore, the first refrigerant sub-flow channel 46 is connected to the portion of the suction refrigerant pipe 31 on the outlet side of the accumulator 29 (see point H in Figure 1).

[0062] The first refrigerant subflow channel 46 has a first expansion valve (first flow rate adjustment mechanism) 48. The first expansion valve 48 is an electrically operated expansion valve. The first expansion valve 48 adjusts the amount of refrigerant flowing through the first refrigerant subflow channel 46.

[0063] The second refrigerant sub-flow channel 66 includes a second cooling section 67 and a second expansion valve (second flow rate adjustment mechanism) 68. The second cooling section 67 further cools the IPM (Intelligent Power Module, second electrical component) 82a of the electrical component unit 70 (see Figure 3). The second expansion valve 68 adjusts the amount of refrigerant flowing to the second cooling section 67. The second expansion valve 68 is an electrically operated expansion valve. The second refrigerant sub-flow channel 66 connects the first heat source side liquid refrigerant pipe (liquid piping) 34a on the heat source side heat exchanger 23 side of the heat source side expansion valve 25 to the second heat source side liquid refrigerant pipe (liquid piping) 34b on the opposite side of the heat source side heat exchanger 23 of the heat source side expansion valve 25 (see points C and D in Figure 1). The second cooling unit 67 is provided to make thermal contact with the heat-generating components of the heat source side control unit 70, such as the electrical components, from the front via the second heat transfer member 67a described later, and to cool them.

[0064] The fourth refrigerant sub-flow channel 61 includes a fourth cooling section 62 and a fourth expansion valve (fourth flow rate adjustment mechanism) 63. The fourth cooling section 62 further cools the IPM (Intelligent Power Module, first electrical component) 81a of the electrical component unit 70 (see Figure 3). The fourth expansion valve 63 expands the refrigerant flowing to the fourth cooling section 62. The fourth expansion valve 63 is an electrically operated expansion valve. The fourth refrigerant sub-flow channel 61 branches off from the liquid flow channel 340 that extends from the heat source side heat exchanger 23 of the heat source side refrigerant main flow channel 300 to the utilization side refrigerant flow channel 500, and flows refrigerant into the gas flow channel 310 on the suction side of the compressor 21 of the heat source side refrigerant main flow channel 300 (see points A and B in Figure 1). The fourth refrigerant sub-flow channel 61 branches off from a position on the side of the user-side refrigerant flow channel 500 rather than from a position on the opposite side of the heat source-side expansion valve 25 from the heat source-side heat exchanger 23, to which the second refrigerant sub-flow channel 66 is connected (see point A in Figure 1). The fourth cooling unit 62 is provided to make thermal contact with electrical components such as heat-generating parts of the heat source-side control unit 70 from the front via the fourth heat transfer member 62a, which will be described later, and to cool them.

[0065] The third refrigerant sub-flow channel 41 branches off from the liquid flow channel 340 (see point E in Figure 1). The third refrigerant sub-flow channel 41 has a third expansion valve (third flow rate adjustment mechanism) 44 that expands the refrigerant flowing inside it. The third expansion valve 44 is an electrically operated expansion valve. The subcooled heat exchanger 45 is located in the liquid flow channel 340 that extends from the heat source side heat exchanger 23 to the utilization side refrigerant flow channel 500. The third refrigerant sub-flow channel 41 causes heat exchange between the refrigerant that has passed through the third expansion valve 44 and the refrigerant flowing in the liquid flow channel 340 of the heat source side refrigerant main flow channel 300 in the subcooled heat exchanger 45. The third refrigerant sub-flow channel 41 allows the refrigerant after heat exchange to flow into the gas flow channel 310 on the suction side of the compressor 21 of the heat source side refrigerant main flow channel 300 (see point F in Figure 1). In other words, the third refrigerant subflow channel 41 is a refrigerant pipe that sends refrigerant branched from the heat source side liquid refrigerant pipe 34 to the suction side of the compressor 21. The third refrigerant subflow channel 41 mainly consists of a refrigerant return inlet pipe 42 and a refrigerant return outlet pipe 43. The refrigerant return inlet pipe 42 is a refrigerant pipe that branches off a portion of the refrigerant flowing through the heat source side liquid refrigerant pipe 34 from the portion between the liquid side end of the heat source side heat exchanger 23 and the liquid side shut-off valve 27 (here, the portion between the heat source side expansion valve 25 and the subcooled heat exchanger 45) and sends it to the inlet of the subcooled heat exchanger 45 on the third refrigerant subflow channel 41 side. The refrigerant return outlet pipe 43 is a refrigerant pipe that sends refrigerant from the outlet of the subcooled heat exchanger 45 on the third refrigerant subflow channel 41 side to the suction refrigerant pipe 31. The refrigerant return outlet pipe 43 of the third refrigerant subflow channel 41 is connected to the portion of the suction refrigerant pipe 31 on the inlet side of the accumulator 29.

[0066] The heat source unit 2 is equipped with various sensors. Specifically, the heat source unit 2 is equipped with a discharge pressure sensor 36 for detecting the pressure of the refrigerant discharged from the compressor 21 (discharge pressure Pd), a discharge temperature sensor 37 for detecting the temperature of the refrigerant discharged from the compressor 21 (discharge temperature Td, hereinafter also referred to as discharge pipe temperature Td), an intake pressure sensor 39 for detecting the pressure of the refrigerant drawn into the compressor 21 (intake pressure Ps), and an intake temperature sensor 40 for detecting the temperature of the refrigerant drawn into the compressor 21 (intake temperature Ts). The heat source unit 2 is also equipped with a heat source side heat exchanger liquid side sensor 38 for detecting the temperature of the refrigerant Tol at the liquid side end of the heat source side heat exchanger 24 (outdoor heat exchanger outlet temperature Tol), and a liquid pipe temperature sensor 49 for detecting the temperature of the refrigerant in the portion of the heat source side liquid refrigerant pipe 34 between the heat source side expansion valve 25 and the liquid side shut-off valve 27 (liquid pipe temperature Tlp). Furthermore, the heat source unit 2 is equipped with an internal air temperature sensor 64 that detects the temperature of the air near the electrical components of the electrical component unit 70 (internal air temperature Ta).

[0067] The heat source side control unit (electrical components unit) 70 is located in the heat source unit casing 11, below the fan module 12, towards the front, and facing the rear side of the upper front panel 16. More specifically, the heat source side control unit 70 is located in front of the compressor 21 and the accumulator 29. The heat source side control unit 70 can be accessed from the outside through an opening 16a that appears when the upper front panel 16 of the heat source unit casing 11 is removed. The opening 16a is bordered by a support column 14 located on the left front, a support column 14 located on the right front, the lower edge of the front plate 12a of the fan module 12, and the upper edge of the lower front panel 17, and opens in the front-to-back direction. The heat source side control unit 70 controls the operation of each part that constitutes the heat source unit 2. The heat source side control unit 70 has a microcomputer and memory provided for controlling the heat source unit 2, and controls the state of the compressor motor 21a, heat source side fan motor 24a, heat source side expansion valve 25, four-way switching valve 22, first expansion valve 48, second expansion valve 68, etc. The heat source side control unit 70 can exchange control signals, etc., with the user side control units 75a, 75b of each user unit 3a, 3b and the remote control 9 via the transmission line 70. The user side control units 75a, 75b, the heat source side control unit 50 and the remote control 9 are connected to each other by the transmission line 8, thereby forming a control unit 7 that controls the operation of the entire refrigeration cycle system 1.

[0068] The control unit 7 is connected to various sensors 36, 37, 38, 39, 40, 49, 57a, 57b, 58a, 58b, 59a, 59b, and 64 so as to be able to receive detection signals, and controls various devices based on these detection signals. The control unit 7 also has a CPU that executes the above-mentioned various controls, and a memory that stores information used for executing the various controls.

[0069] (1-3) Refrigerant connecting pipes: The liquid side refrigerant connecting pipe 5 and the gas side refrigerant connecting pipe 6 are refrigerant pipes that are installed on-site when the refrigeration cycle device 1 is installed at a building or other installation location.

[0070] In this embodiment of the refrigeration cycle device 1 having multiple utilization units 3a and 3b, the liquid-side refrigerant communication pipe 5 has branched sections corresponding to each utilization unit 3a and 3b, and the gas-side refrigerant communication pipe 6 also has branched sections corresponding to each utilization unit 3a and 3b.

[0071] (2) Refrigerant circuit Refrigeration cycle In the refrigerant circuit 10 of the refrigeration cycle device 1, cooling operation and heating operation are mainly performed by switching the connection state of the four-way switching valve 22.

[0072] (2-1) Cooling Operation Cooling operation is performed with the four-way switching valve 22 switched so that the discharge side of the compressor 21 is on the heat source side heat exchanger 23 side, and the suction side of the compressor 21 is on the respective user side heat exchangers 52a and 52b sides.

[0073] The compressor 21 is controlled to a frequency that, for example, handles the cooling load in each utilization unit 3a, 3b. As a result, the low-pressure refrigerant drawn into the compressor 21 is discharged from the compressor 21 as high-pressure refrigerant and flows into the heat source side heat exchanger 23 via the four-way switching valve 22.

[0074] The refrigerant flowing into the heat source side heat exchanger 23 releases its heat and condenses. The refrigerant flowing out of the heat source side heat exchanger 23 passes through the heat source side expansion valve 25, which is controlled to be fully open by the control unit 7 during cooling operation.

[0075] The refrigerant that has passed through the heat source side expansion valve 25 is sent to the liquid side refrigerant connecting pipe 5 after passing through the liquid side shut-off valve 27.

[0076] The refrigerant flowing through the liquid-side refrigerant communication pipe 5 is branched and then sent to each utilization unit 3a and 3b.

[0077] The refrigerant flowing into each utilization unit 3a and 3b is reduced in pressure by the utilization-side expansion valves 51a and 51b until it reaches the low pressure of the refrigeration cycle. The valve opening of the utilization-side expansion valves 51a and 51b is controlled by the control unit 7, for example, so that the superheating degree of the refrigerant at the outlet side of the utilization-side heat exchangers 52a and 52b reaches a predetermined target superheating degree.

[0078] The refrigerant, depressurized in the respective utilization-side expansion valves 51a and 51b of each utilization unit 3a and 3b, evaporates in the respective utilization-side heat exchangers 52a and 52b. The refrigerant evaporated in each utilization-side heat exchanger 51a and 51b merges and flows through the gas-side refrigerant connecting pipe 6.

[0079] The refrigerant that has flowed through the gas-side refrigerant communication pipe 6 is drawn back into the compressor 21 via the gas-side shut-off valve 28, the four-way switching valve 22, and the accumulator 29 of the heat source unit 2.

[0080] In cooling operation, a portion of the refrigerant flowing through the heat source side liquid refrigerant pipe 34 is branched off at the portion of the heat source side liquid refrigerant pipe 34 closer to the heat source side heat exchanger 23 than the subcooled heat exchanger 45, and this first refrigerant sub-flow channel 46 sends the refrigerant to the compressor 21.

[0081] The first refrigerant sub-flow channel 46 cools the internal storage space of the electrical component casing 70a. In other words, the first refrigerant sub-flow channel 46 cools the internal air of the electrical component unit 70. The control unit 7 controls the opening degree of the first expansion valve 48 based on the discharge temperature (discharge pipe temperature) Td of the compressor 21. When the discharge temperature Td rises to the discharge temperature threshold Tdx, the control unit 7 controls the opening degree of the first expansion valve 48 to increase until the discharge temperature Td falls below the discharge temperature threshold Tdx.

[0082] Furthermore, during cooling operation, the high-temperature, high-pressure liquid refrigerant condensed in the heat source side heat exchanger 23 flows through the second refrigerant sub-flow channel 66 to cool the electrical component unit 70. The control unit 7 controls the opening degree of the second expansion valve 68 based on the temperature of the electrical component unit 70. In other words, the control unit 7 adjusts the opening degree of the second expansion valve 68 based on the internal air temperature Ta detected by the internal air temperature sensor 64.

[0083] Furthermore, during cooling operation, the refrigerant in a gas-liquid two-phase state evaporates from the electrical equipment unit 70 by the fourth expansion valve 63 provided in the fourth refrigerant sub-flow path 61, absorbing heat and returning to the gas flow path 310 on the suction side of the compressor 21. The control unit 7 controls the opening degree of the fourth expansion valve 63 based on the temperature of the electrical equipment unit 70. In other words, the control unit 7 controls the opening degree of the fourth expansion valve 63 based on the internal air temperature Ta detected by the internal air temperature sensor 64.

[0084] Furthermore, during cooling operation, a third refrigerant sub-flow channel 41 branches off a portion of the refrigerant flowing through the heat source side liquid refrigerant pipe 34 and sends it to the compressor 21. A subcooling heat exchanger 45 cools the portion of the heat source side liquid refrigerant pipe 34 that flows on the heat source side heat exchanger 23 side of the liquid side shut-off valve 27 using the refrigerant flowing through the third refrigerant sub-flow channel 41. This operation cools the portion of the heat source side liquid refrigerant pipe 34 between the subcooling heat exchanger 45 and the heat source side heat exchanger 23. The control unit 7 controls the opening of the third expansion valve 44 to be increased when the liquid pipe temperature Tlp is higher than the target liquid pipe temperature Tlpt, and controls the opening of the third expansion valve 44 to be decreased when the liquid pipe temperature Tlp is lower than the target liquid pipe temperature Tlpt.

[0085] (2-2) Heating Operation Heating operation is performed with the four-way switching valve 22 switched so that the discharge side of the compressor 21 is connected to the respective user-side heat exchangers 52a and 52b, and the suction side of the compressor 21 is connected to the heat source-side heat exchanger 23.

[0086] The compressor 21 is controlled by frequency to handle the heating load in each utilization unit, for example. As a result, the high-pressure refrigerant discharged from the compressor 21 flows to each utilization unit 3a, 3b via the four-way switching valve 22 and the gas-side refrigerant communication pipe 6.

[0087] Here, the refrigerant that has passed through the gas-side refrigerant communication pipe 6 branches off and flows into the respective utilization units 3a and 3b.

[0088] The refrigerant flowing into each utilization unit 3a and 3b dissipates heat and condenses in each utilization-side heat exchanger 52a and 52b. The valve opening of each utilization-side expansion valve 51a and 51b is controlled during heating operation, for example, so that the degree of subcooling of the refrigerant flowing out of the outlets of the utilization-side heat exchangers 52a and 52b reaches a predetermined value.

[0089] In this way, the refrigerants that condense in each of the user-side heat exchangers 52a and 52b and pass through each of the user-side expansion valves 51a and 51b merge and flow through the liquid-side refrigerant connecting pipe 5.

[0090] The refrigerant flowing through the liquid-side refrigerant communication pipe 5 is supplied to the heat source unit 2 through the liquid-side shut-off valve 27. The refrigerant that has passed through the liquid-side shut-off valve 27 is reduced in pressure to the low pressure of the refrigeration cycle in the heat source side expansion valve 25. Specifically, for example, the valve opening of the heat source side expansion valve 25 is controlled so that the superheating degree of the refrigerant flowing on the suction side of the compressor 21 reaches the target superheating degree.

[0091] The refrigerant sent to the heat source side heat exchanger 23 evaporates and is then drawn back into the compressor 21 via the four-way switching valve 22 and the accumulator 29.

[0092] In heating operation, the control unit 7 fully closes the opening of the first expansion valve 48 to prevent refrigerant from flowing into the first refrigerant sub-flow path 46. The control unit 7 also fully closes the opening of the second expansion valve 68 to prevent refrigerant from flowing into the second refrigerant sub-flow path 66. The control unit 7 also fully closes the opening of the fourth expansion valve 63 to prevent refrigerant from flowing into the fourth refrigerant sub-flow path 61. The control unit 7 also fully closes the opening of the third expansion valve 44 to prevent refrigerant from flowing into the third refrigerant sub-flow path 41 and the first refrigerant sub-flow path 46.

[0093] (3) Figure 3 of the configuration diagram of the heat source side control unit is a schematic plan view of the inside of the heat source side control unit 70. Figure 4 is a schematic front view of the front part of the inside of the heat source side control unit 70. Figure 5 is a schematic rear view of the back part of the inside of the heat source side control unit 70.

[0094] The heat source side control unit (electrical component unit) 70 includes an electrical component casing (enclosure) 70a, a first circuit board 81, and a second circuit board 82. The heat source side control unit 70 may also have other circuit boards. The electrical component unit 70's enclosure is sealed by the electrical component casing 70a.

[0095] The electrical component casing 70a has a rear surface 77, a top surface 75, a bottom surface 76, a right side surface 74, a left side surface 73, a front cover 72, and a partition plate 71. The partition plate 71 extends vertically and horizontally to divide the interior of the electrical component casing 70a into a front side and a rear side. The partition plate 71 is located near the center in the front-to-back direction inside the electrical component casing 70a. As a result, the interior of the electrical component casing 70a is divided into a first space S1 which is on the rear side relative to the partition plate 71, and a second space S2 which is on the front side relative to the partition plate 71. For example, the second space S2 may be further divided into an upper space and a lower space by another partition plate.

[0096] The first substrate 81 and the second substrate 82 are both plate-shaped members that extend in the vertical, horizontal, and vertical directions, and have a rectangular shape when viewed from the front, and are fixed to the partition plate 71.

[0097] The first circuit board 81 is equipped with an Intelligent Power Module (IPM, first electrical component) 81a, which is an electrical component for the inverter of the compressor 21 and is a heat-generating component. The second circuit board 82 is equipped with an Intelligent Power Module (IPM, second electrical component) 82a, which is an electrical component used for the heat source side fan 24 and is a heat-generating component. The amount of heat generated by the IPM (first electrical component) 81a is greater than the amount of heat generated by the IPM (second electrical component) 82a. Both IPM 81a and IPM 82a are housed in the first space S1.

[0098] (4) Cooling by the first refrigerant sub-flow channel The first refrigerant sub-flow channel 46 cools the internal air of the electrical component casing 70a, and the IPM 81a and IPM 82a are cooled by the air cooled by the first refrigerant sub-flow channel 46.

[0099] As shown in Figure 5, the first space S1 of the heat source side control unit 70 is cooled by the first cooling section 47 of the first refrigerant subflow channel 46. The first cooling section 47 of the first refrigerant subflow channel 46 is provided so as to be in thermal contact with the electrical component casing 70a from the rear side via a first heat transfer member 47a. The first heat transfer member 47a has a plane that extends parallel to the rear surface 77 of the electrical component casing 70a, and is used so that this plane is in surface contact with the rear surface 77. The first cooling section 47 extends from the lower end to the upper end on the rear side of the electrical component casing 70a, then folds back via a U-shape and extends to the lower end.

[0100] In this way, in the first space S1 of the heat source side control unit 70, the internal air of the electrical component casing 70a is cooled by the first cooling section 47 of the first refrigerant subflow channel 46, thereby cooling the heat-generating components IPM 81a and IPM 82a.

[0101] (5) Cooling by the second refrigerant subflow channel. On the side of the partition plate 71 of the heat source side control unit 70 facing the second space S2, the second cooling section 67 of the second refrigerant subflow channel 66 is provided so as to be in thermal contact with the heat source side control unit 70 via the second heat transfer member 67a. The second heat transfer member 67a has a plane that extends parallel to the partition plate 71 and is used so as to be in surface contact with the partition plate 71. The second cooling section 67 extends from the lower end to the upper end on the front side of the electrical component casing 70a, then folds back via a U-shape and extends to the lower end.

[0102] The partition plate 71 of the heat source side control unit 70 is cooled by the second cooling unit 67 of the second refrigerant subflow channel 66, thereby further cooling the heat-generating component IPM 82a provided on the back side of the partition plate 71.

[0103] If an IPM 82a is provided on the front side of the partition plate 71, the second cooling section 67 of the second refrigerant subflow channel 66 may be provided so as to be in thermal contact with the partition plate 71 from the rear side via the second heat transfer member 67a.

[0104] (6) The fourth cooling section 62 of the fourth refrigerant subflow channel 61 is provided so as to be in thermal contact with the side of the partition plate 71 of the heat source side control unit 70 of the fourth refrigerant subflow channel 70 that faces the second space S2, via the fourth heat transfer member 62a. The fourth heat transfer member 62a has a plane that extends parallel to the partition plate 71 and is used so as to be in surface contact with the partition plate 71. The fourth cooling section 62 extends from the lower end to the upper end on the front side of the electrical component casing 70a, then folds back via a U shape and extends to the lower end.

[0105] The partition plate 71 of the heat source side control unit 70 is cooled by the fourth cooling unit 62 of the fourth refrigerant subflow channel 61, thereby further cooling the heat-generating component IPM (first electrical component) 81a provided on the back side of the partition plate 71.

[0106] If an IPM 81a is provided on the front side of the partition plate 71, the fourth cooling section 62 of the fourth refrigerant subflow channel 61 may be provided so as to be in thermal contact with the partition plate 71 from the rear side via the first heat transfer member 62a.

[0107] (7) Features (7-1) The heat source unit 2 of the refrigeration cycle device 1 according to this embodiment comprises an electrical equipment unit 70, a heat source side refrigerant main flow path 300, and a first refrigerant sub-flow path 46. The heat source side refrigerant main flow path 300 includes an accumulator 29, a compressor 21, a heat source side heat exchanger 23, and a heat source side expansion valve 25. The heat source side refrigerant main flow path 300 is connected to the utilization side refrigerant flow path 500 of utilization units 3a and 3b to form a refrigerant circuit 10. The first refrigerant sub-flow path 46 has a first cooling section 47 that cools the IPM 81a and IPM 82a of the electrical equipment unit 70. The first refrigerant sub-flow channel 46 branches off from the liquid flow channel 340 that extends from the heat source side heat exchanger 23 to the user side refrigerant flow channel 500 in the heat source side refrigerant main flow channel 300, and flows refrigerant into the gas flow channel 310 between the accumulator 29 and the compressor 21 in the heat source side refrigerant main flow channel 300.

[0108] Conventional cooling circuits for electrical components have one end connected to a liquid pipe and the other end connected to the upstream side of the accumulator. Furthermore, with the use of R32 as the refrigerant, a liquid injection circuit is required to suppress the rise in discharge pipe temperature, which complicates the circuit and increases costs.

[0109] In this refrigeration cycle system 1, the first refrigerant sub-flow channel 46 that cools the electrical component unit 70 has a liquid injection function, and the outlet of the first refrigerant sub-flow channel 46 is merged between the compressor 21 and the accumulator 29. This reduces costs. Also, when R32 refrigerant is introduced into the accumulator 29, the injection effect is diminished. In this refrigeration cycle system 1, the reduction in the injection effect can be suppressed by directly injecting liquid refrigerant into the compressor 21.

[0110] In the heat source unit 2 of this refrigeration cycle device 1, the first refrigerant subflow channel 46 can be used to cool the electrical component unit 70, and can also be used to cool the gaseous refrigerant drawn into the compressor 21.

[0111] (7-2) The heat source unit 2 of the refrigeration cycle device 1 according to this embodiment includes a first expansion valve 48 and a control unit 7. The first expansion valve 48 adjusts the flow rate of refrigerant flowing through the first refrigerant subflow channel 46. The control unit 7 controls the opening degree of the first expansion valve 48 based on the discharge temperature Td of the compressor 21.

[0112] The control unit 7 uses the discharge temperature Td of the compressor 21 as a substitute temperature for the temperature of the internal port of the compressor 21, which cannot be directly detected. This makes it possible to ensure the necessary cooling capacity and protect the compressor 21 at the same time.

[0113] In the heat source unit 2 of this refrigeration cycle device 1, when the discharge temperature Td of the compressor 21 rises, the opening of the first expansion valve 48 is increased to cool the gaseous refrigerant drawn into the compressor 21, thereby lowering the discharge temperature Td of the compressor 21 and protecting the compressor 21.

[0114] (7-3) In the heat source unit 2 of the refrigeration cycle device 1 according to this embodiment, the electrical component unit 70 has its housing space sealed by the electrical component casing 70a. The first refrigerant subflow channel 46 cools the housing space inside the electrical component casing 70a.

[0115] In this refrigeration cycle device 1, the heat source unit 2 lowers the discharge pipe temperature Td of the compressor 21 and allows the housing space for electrical components to be cooled with a smaller amount of cooling compared to when cooling electrical components.

[0116] (7-4) The heat source unit 2 of the refrigeration cycle device 1 according to this embodiment further comprises a second refrigerant subflow channel 66. The second refrigerant subflow channel 66 has a second cooling section 67 and a second expansion valve 68. The second cooling section 67 cools the second part of the electrical component unit 70. The second expansion valve 68 adjusts the amount of refrigerant flowing to the second cooling section 67. The second refrigerant subflow channel 66 connects the first heat source side liquid refrigerant pipe 34a on the heat source side heat exchanger 23 side of the heat source side expansion valve 25 and the second heat source side liquid refrigerant pipe 34b on the opposite side of the heat source side heat exchanger 23 of the heat source side expansion valve 25. The first refrigerant sub-flow path 46 branches off from a position on the user-side refrigerant circuit 500 side of the liquid flow path 340, which extends from the heat source-side heat exchanger 23 of the heat source-side refrigerant main flow path 300 to the user-side refrigerant flow path 500, at a position on the user-side refrigerant circuit 500 side of the heat source-side expansion valve 25 to which the second refrigerant sub-flow path 66 is connected, rather than at a position on the opposite side of the heat source-side heat exchanger 23 of the heat source-side expansion valve 25.

[0117] In the heat source unit 2 of this refrigeration cycle device 1, the first refrigerant subflow path 46 branches off in the liquid flow path 340 from a position closer to the user-side refrigerant circuit 500 than the second refrigerant subflow path 66, thereby ensuring a sufficient amount of refrigerant for cooling in the second refrigerant subflow path 66.

[0118] (7-5) The heat source unit 2 of the refrigeration cycle device 1 according to this embodiment further comprises a fourth refrigerant subflow path 61. The fourth refrigerant subflow path 61 has a fourth cooling section 62 and a fourth expansion valve 64. The fourth cooling section 62 cools the IPM 81a of the electrical component unit 70. The fourth expansion valve 63 expands the refrigerant flowing to the fourth cooling section 62. The fourth refrigerant subflow path 61 branches off from the liquid flow path 340 that extends from the heat source side heat exchanger 23 of the heat source side refrigerant main flow path 300 to the utilization side refrigerant flow path 500, and flows refrigerant into the gas flow path 310 on the suction side of the compressor 21 of the heat source side refrigerant main flow path 300.

[0119] In conventional cooling circuits, electrical components used in the blower fan and the compressor inverter were cooled with a high-temperature, high-pressure liquid coolant. However, conventional cooling circuits had insufficient cooling capacity, especially when the heat generated by electrical components such as the compressor inverter increased.

[0120] In the heat source unit 2 of this refrigeration cycle device 1, when the heat source side heat exchanger 23, which cools the refrigerant with outside air, is used as a condenser, the high-temperature, high-pressure liquid refrigerant condensed in the heat source side heat exchanger 23 is expanded by the fourth expansion valve 63 of the fourth refrigerant sub-flow channel 61 to lower its temperature. This two-phase gaseous refrigerant then absorbs heat from the electrical component unit and evaporates, returning to the gas flow channel 310 on the suction side of the compressor 21. This makes it possible to cool the electrical component unit 70 more strongly than in the conventional method, where the electrical component unit 70 was cooled by a high-temperature, high-pressure liquid refrigerant.

[0121] (7-6) In the heat source unit of the refrigeration cycle device 1 according to this embodiment, the heat source side refrigerant main flow path 300 further includes a subcooled heat exchanger 45. The subcooled heat exchanger 45 is located in a liquid flow path 340 that extends from the heat source side heat exchanger 23 to the utilization side refrigerant flow path 500. The heat source unit 2 further includes a third refrigerant subflow path 41. The third refrigerant subflow path 41 branches off from the liquid flow path 340. The third refrigerant subflow path 41 has a third expansion valve 44 that expands the refrigerant flowing inside it. The third refrigerant subflow path 41 causes heat exchange between the refrigerant that has passed through the third expansion valve 44 and the refrigerant flowing in the liquid flow path 340 of the heat source side refrigerant main flow path 300 in the subcooled heat exchanger 45. The third refrigerant subflow path 41 allows the refrigerant after heat exchange to flow into the gas flow path on the suction side of the compressor 21 of the heat source side refrigerant main flow path.

[0122] In the heat source unit of this refrigeration cycle device 1, when the heat source side heat exchanger 23, which cools the refrigerant with outside air, is used as a condenser, the high-temperature, high-pressure liquid refrigerant condensed in the heat source side heat exchanger 23 is expanded in the third expansion valve 44 of the third refrigerant sub-flow channel 41 to lower its temperature, and this refrigerant then exchanges heat with the high-temperature, high-pressure liquid refrigerant, thereby cooling the high-temperature, high-pressure liquid refrigerant condensed in the heat source side heat exchanger 23.

[0123] (7-7) In the heat source unit of the refrigeration cycle device 1 according to this embodiment, the control unit 7 controls the opening degree of the second expansion valve 68 or the fourth expansion valve 63 based on the temperature of the electrical equipment unit 70.

[0124] In this refrigeration cycle device 1, the heat source unit 2 controls the opening degree of the second expansion valve 68 or the fourth expansion valve 63 based on the temperature of the electrical component unit 70, thereby adjusting the temperature or amount of refrigerant according to the temperature of the electrical component unit 70 and cooling the electrical component unit 70.

[0125] (7-8) In the heat source unit of the refrigeration cycle device 1 according to this embodiment, the electrical equipment unit 70 includes IPM 81a and IPM 82a. The fourth refrigerant subflow channel 61 cools IPM 81a.

[0126] In this refrigeration cycle system's heat source unit, the fourth refrigerant sub-flow channel 61 can cool specific electrical components.

[0127] (7-9) In the heat source unit 2 of the refrigeration cycle device 1 according to this embodiment, the heat output of IPM 81a is greater than the heat output of IPM 82a.

[0128] In the heat source unit 2 of this refrigeration cycle device 1, the IPM 81a, which generates a large amount of heat, can be cooled by a fourth refrigerant sub-flow channel 61 that lowers the temperature of the high-temperature, high-pressure liquid refrigerant.

[0129] (7-10) In the heat source unit of the refrigeration cycle device 1 according to this embodiment, the fourth refrigerant subflow channel 61 branches off from a position on the side of the utilization-side refrigerant flow channel 500 rather than from a position on the opposite side of the heat source-side heat exchanger 23 of the heat source-side expansion valve 25 to which the second refrigerant subflow channel 66 is connected, in the liquid flow channel 340 that extends from the heat source-side heat exchanger 23 of the heat source-side refrigerant flow channel 300 to the utilization-side refrigerant flow channel 500.

[0130] In the heat source unit of this refrigeration cycle device, the fourth refrigerant subflow channel 61 branches off in the liquid flow channel 340 from a position closer to the utilization-side refrigerant flow channel 500 than the second refrigerant subflow channel 66, thereby ensuring a sufficient amount of refrigerant for cooling in the second refrigerant subflow channel 66.

[0131] (7-11) The refrigeration cycle device 1 according to this embodiment comprises a heat source unit 2 and utilization units 3a and 3b. The utilization units 3a and 3b are connected to the heat source unit 2.

[0132] In this refrigeration cycle device 1, the first refrigerant sub-flow channel 46 can be used to cool the electrical component unit 70, and can also be used to cool the gaseous refrigerant drawn into the compressor 21.

[0133] (8) Modifications (8-1) Modification 1A The refrigeration cycle device 1 is not limited to a device used for both cooling and heating, but may also be a device used only for cooling.

[0134] (8-2) Modification 1B The control unit 7 may control the opening degree of the first expansion valve 48 based on the discharge temperature Td of the compressor and the temperature of the electrical equipment unit 70. The temperature of the electrical equipment unit 70 may be detected by detecting the internal air temperature Ta with the internal air temperature sensor 64, or the temperature of the electrical equipment unit 70 may be detected by a sensor (not shown) that detects the air temperature in the space S1 of the electrical equipment unit 70.

[0135] In modified example 1B, when the discharge pipe temperature Td of the compressor 21 rises and the temperature of the electrical component unit 70 rises, the opening of the first expansion valve 48 is increased to cool the gas refrigerant drawn into the compressor 21, thereby lowering the discharge temperature Td of the compressor 21 and also achieving cooling of the electrical component unit 70.

[0136] (8-3) Modification 1C In this embodiment, the case in which the first refrigerant subflow channel 46 cools IPM 81a and IPM 82a, the fourth cooling section 62 of the fourth refrigerant subflow channel 61 cools IPM 81a, and the second cooling section 67 of the second refrigerant subflow channel 66 cools IPM 82a has been described. Alternatively, the fourth cooling section 62 of the fourth refrigerant subflow channel 61 may cool IPM 81a and IPM 82a.

[0137] (8-4) Although embodiments of the present disclosure have been described above, it will be understood that various modifications to the form and details are possible without departing from the spirit and scope of the present disclosure as described in the claims.

[0138] 1 Refrigeration cycle unit 2 Heat source unit 3a, 3b Utilization unit 5 Liquid refrigerant connecting piping 6 Gas refrigerant connecting piping 7 Control unit 10 Refrigerant circuit 11 Heat source unit casing 21 Compressor 23 Heat source side heat exchanger 24 Heat source side fan 25 Heat source side expansion valve (heat source side main expansion mechanism) 29 Accumulator 34a, 34b Liquid piping 41 Third refrigerant sub-flow path 44 Third expansion valve (third flow rate adjustment mechanism) 45 Subcooled heat exchanger (refrigerant cooler) 46 First refrigerant sub-flow path 47 First cooling section 48 First expansion valve (first flow rate adjustment mechanism) 61 Fourth refrigerant sub-flow path 62 Fourth cooling section 63 Fourth expansion valve (fourth flow rate adjustment mechanism) 66 Second refrigerant sub-flow path 67 Second cooling section 68 Second expansion valve (second flow rate adjustment mechanism) 70 Heat source side control unit (electrical component unit) 70a Electrical component casing (enclosure) 81 First circuit board 81a IPM (first electrical component) 82 Second circuit board 82a IPM (second electrical component) 300 Heat source side refrigerant main flow path 310 Gas flow path 340 Liquid flow path 500 Refrigerant flow path on the user side

[0139] Japanese Patent Publication No. 2022-146443

Claims

1. A heat source unit (2) of a refrigeration cycle device, comprising: an electrical component unit (70); an accumulator (29); a compressor (21); a heat source side heat exchanger (23); a heat source side main refrigerant flow path (300) which is connected to the user side refrigerant flow path (500) of user units (3a, 3b) to form a refrigerant circuit (10); and a first refrigerant sub-flow path (46) which has a first cooling section (47) for cooling the first part of the electrical component unit and the second part of the electrical component unit, wherein the first refrigerant sub-flow path branches off from a liquid flow path (340) extending from the heat source side heat exchanger of the heat source side main refrigerant flow path to the user side refrigerant flow path and flows refrigerant into a gas flow path (310) between the accumulator and the compressor of the heat source side main refrigerant flow path.

2. A heat source unit for a refrigeration cycle apparatus according to claim 1, comprising: a first flow rate adjustment mechanism (48) for adjusting the flow rate of the refrigerant flowing through the first refrigerant subflow channel; and a control unit (7), wherein the control unit controls the opening degree of the first flow rate adjustment mechanism based on the discharge pipe temperature (Td) of the compressor.

3. The heat source unit of the refrigeration cycle apparatus according to claim 2, wherein the control unit controls the opening degree of the first flow rate adjustment mechanism based on the discharge pipe temperature of the compressor and the temperature of the electrical equipment unit.

4. The electrical component unit is enclosed by a housing (70a), and the housing space of the electrical component unit is sealed by the housing, and the first refrigerant subflow channel cools the housing space inside the housing, a heat source unit for a refrigeration cycle device according to any one of claims 1 to 3.

5. A heat source unit for a refrigeration cycle device according to any one of claims 2 to 4, further comprising: a second refrigerant subflow channel (66) having a second cooling section (67) for cooling a second part of the electrical component unit and a second flow rate adjustment mechanism (68) for adjusting the amount of refrigerant flowing to the second cooling section, wherein the second refrigerant subflow channel connects a liquid pipe (34a) on the heat source side heat exchanger side of the heat source side main expansion mechanism to a liquid pipe (34b) on the opposite side of the heat source side heat exchanger side of the heat source side main expansion mechanism, and the first refrigerant subflow channel branches off from a position on the side of the utilization side refrigerant circuit rather than a position on the opposite side of the heat source side heat exchanger side of the heat source side main expansion mechanism to which the second refrigerant subflow channel is connected.

6. A heat source unit for a refrigeration cycle apparatus according to claim 5, further comprising a fourth refrigerant subflow channel (61) having a fourth cooling section (62) for cooling a first part of the electrical component unit and a fourth flow rate adjustment mechanism (63) for expanding the refrigerant flowing through the fourth cooling section, wherein the fourth refrigerant subflow channel branches off from a liquid flow channel extending from the heat source side heat exchanger to the utilization side refrigerant flow channel of the heat source side refrigerant main flow channel and flows the refrigerant through the gas flow channel on the suction side of the compressor of the heat source side refrigerant main flow channel.

7. The heat source unit of the refrigeration cycle apparatus according to claim 6, wherein the heat source side refrigerant main flow path further comprises a subcooling heat exchanger (45) disposed in the liquid flow path extending from the heat source side heat exchanger to the utilization side refrigerant flow path, and further comprises a third refrigerant subflow path (41) branching off from the liquid flow path, the third refrigerant subflow path has a third flow rate adjustment mechanism (44) that expands the refrigerant flowing inside it, the refrigerant that has passed through the third flow rate adjustment mechanism and the refrigerant flowing in the liquid flow path of the heat source side refrigerant main flow path exchange heat in the subcooling heat exchanger, and the refrigerant after heat exchange flows into the gas flow path on the suction side of the compressor of the heat source side refrigerant main flow path.

8. The heat source unit of the refrigeration cycle device according to claim 6 or 7, wherein the control unit controls the opening degree of the second flow rate adjustment mechanism or the fourth flow rate adjustment mechanism based on the temperature of the electrical component unit.

9. The electrical component unit includes a first electrical component (81a) and a second electrical component (82a), and the fourth refrigerant subflow channel cools the first electrical component, the heat source unit of the refrigeration cycle device according to any one of claims 6 to 8.

10. The heat source unit of the refrigeration cycle device according to claim 9, wherein the heat generated by the first electrical component is greater than the heat generated by the second electrical component.

11. The heat source unit of a refrigeration cycle apparatus according to any one of claims 6 to 10, wherein the fourth refrigerant subflow path branches off from a position on the side of the utilization-side refrigerant flow path, rather than from a position on the opposite side of the heat source-side heat exchanger of the heat source-side main expansion mechanism to which the second refrigerant subflow path is connected, in a liquid flow path extending from the heat source-side heat exchanger of the heat source-side main expansion mechanism.

12. A refrigeration cycle device (1) comprising: a heat source unit (2) according to any one of claims 1 to 11; and one or more utilization units (3a, 3b) connected to the heat source unit.

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