Heat pump apparatus and heat pump system

Abstract

The present disclosure provides a heat pump apparatus 1 capable of improving energy saving performance. The heat pump apparatus 1 comprises: a refrigerant circuit 11; heat source piping 12; utilization piping 13; a control valve 14; and a control unit 15. The control valve 14 can be switched between a first mode M1, in which a flow rate F of a heat source fluid Fh in relation to a prescribed pressure range PvR is adjusted to a first flow rate F1, and a second mode M2, in which the flow rate F of the heat source fluid Fh in relation to the prescribed pressure range PvR is adjusted to a second flow rate F2 which is greater than the first flow rate F1, by changing a flow passage width Wf by using an adjustment mechanism 14B. The control unit 15 switches between the first mode M1 and the second mode M2 by controlling the adjustment mechanism 14B of the control valve 14 according to an index related to a load of a utilization circuit 3.

Description

Heat pump device and heat pump system

[0001] The present disclosure relates to a heat pump device and a heat pump system.

[0002] Conventionally, an invention related to a cooling and heating water control method of a cooling and heating source machine is known (see, for example, Patent Document 1). The cooling and heating water control method described in Patent Document 1 is premised on including a cooling and heating source machine, a cooling and heating water pump, a plurality of secondary side facilities, a flow rate adjustment valve of the secondary side facilities, a bypass pipe, and a flow rate adjustment valve of the bypass pipe.

[0003] The cooling and heating source machine is connected to a cooling and heating water piping system and a cooling water piping system. The cooling and heating water pump can perform inverter control to circulate the cooling and heating water generated by the cooling and heating source machine in the cooling and heating water piping system. The plurality of secondary side facilities are connected to the cooling and heating water piping system in parallel with each other. The flow rate adjustment valve of the secondary side facilities adjusts the flow rate of the cooling and heating water to each secondary side facility according to the load. The bypass pipe bypasses the secondary side facilities in the cooling and heating water piping system and returns the cooling and heating water from the outlet side to the inlet side of the cooling and heating source machine. The flow rate adjustment valve of the bypass pipe is provided in the bypass pipe.

[0004] This conventional cooling and heating water control method detects the valve opening degree of the flow rate adjustment valve of each secondary side facility, and reduces the water supply pressure of the cooling and heating water pump by inverter control so that the valve opening degree of the flow rate adjustment valve of the secondary side facility with the largest valve opening degree becomes almost fully open. According to Patent Document 1, since the above cooling and heating water control method controls the pump rotation speed by inverter control to reduce the flow rate, it is said that maximum energy saving can be expected.

[0005] Japanese Patent Application Laid-Open No. 2006-38379

[0006] There is a heat pump system that supplies a heat source fluid to a heat pump device and uses the cold heat of the heat source fluid for cooling or heating a use fluid in the heat pump device. In such a system, the flow rate of the heat source fluid in the supply system of the heat source fluid is adjusted not only by a plurality of pumps existing in the supply system of the heat source fluid but also by a plurality of pumps and valves mounted on each heat pump device.

[0007] Therefore, applying the chilled / hot water control method described in Patent Document 1 to the heat pump system described above would involve controlling the supply system for the heat source fluid and numerous pumps and valves included in the heat pump device. As a result, rapid changes in the flow rate of the heat source fluid and hunting to avoid these changes may occur, potentially reducing energy efficiency.

[0008] This disclosure provides a heat pump device and a heat pump system that can improve energy efficiency.

[0009] A first aspect of this disclosure is a refrigerant circuit (11) that performs a refrigeration cycle, including a compressor (111) for compressing a refrigerant (Fr), a first heat exchanger (112) for exchanging heat between the refrigerant (Fr) and a heat source fluid (Fh), a pressure reducing mechanism (113) for reducing the pressure of the refrigerant (Fr), and a second heat exchanger (114) for exchanging heat between the refrigerant (Fr) and a utilization fluid (Fu), and the heat source fluid in the first heat exchanger (112) A heat source conduit (12) through which (Fh) passes, a utilization conduit (13) through which the utilization fluid (Fu) passes to the second heat exchanger (114), a control valve (14) provided in the heat source conduit (12) and including a differential pressure adjustment mechanism (14A) that uses the differential pressure (ΔPv) of the heat source fluid (Fh) to maintain the flow rate (F) of the heat source fluid (Fh) within a predetermined pressure range (PvR) within a certain range, and the control valve (14) The heat pump device (1) is provided, comprising a control unit (15) for controlling the flow path (Wf), wherein the control valve (14) includes an adjustment mechanism (14B) for changing the flow path width (Wf), and by changing the flow path width (Wf) with the adjustment mechanism (14B), it is possible to switch between a first mode (M1) in which the flow rate (F) of the heat source fluid (Fh) for the predetermined pressure range (PvR) is adjusted to a first flow rate (F1), and a second mode (M2) in which the flow rate (F) of the heat source fluid (Fh) for the predetermined pressure range (PvR) is adjusted to a second flow rate (F2) which is greater than the first flow rate (F1), and the control unit (15) controls the adjustment mechanism (14B) according to an indicator of the load of the utilization circuit (3) that circulates the utilization fluid (Fu) in the utilization pipeline (13) to switch between the first mode (M1) and the second mode (M2).

[0010] According to the first point of view described above, a heat pump device (1) capable of improving energy efficiency can be provided.

[0011] A second aspect of this disclosure is that, in the heat pump device (1) according to the first aspect, the control valve (14) can be changed to a transient mode (TR) in which the flow rate (F) of the heat source fluid (Fh) with respect to the predetermined pressure range (PvR) is adjusted to a transient flow rate (Ftr) that is smaller than the first flow rate (F1) by changing the flow path width (Wf) by the adjustment mechanism (14B), and the control unit (15) may switch the control valve (14) to the transient mode (TR) in a transient state in which the differential pressure (ΔP) of the refrigerant (Fr) between the discharge side and the suction side of the compressor (111) is less than or equal to a predetermined value (Ptr).

[0012] From the second perspective described above, for example, a transient state is defined as a state in which the differential pressure (ΔP) between the discharge side and the suction side of the compressor (111) drops below a predetermined value (Ptr), such as during the period from the start-up of the compressor (111) to steady-state operation, or when some abnormality occurs during the operation of the compressor (111). In this transient state, the control unit (15) switches the control valve (14) to transient mode (TR). As a result, the flow rate (F) of the heat source fluid (Fh) flowing through the heat source pipeline (12) is adjusted by the adjustment mechanism (14B) to a transient flow rate (Ftr) that is smaller than the first flow rate (F1). This makes it possible to suppress problems caused by excessive heat source fluid (Fh) passing through the first heat exchanger (112) during the transient state of the compressor (111). Furthermore, in the heat source circuit (2) that circulates the heat source fluid (Fh) through the heat source pipeline (12), the flow rate of the heat source fluid (Fh) can be reduced, thereby improving energy efficiency.

[0013] A third aspect of this disclosure is that, in the heat pump device (1) according to the first or second aspect, the index may include the rotational speed (R) of the compressor (111).

[0014] From the third point of view described above, the rotational speed (R) of the compressor (111) can be used as an indicator of the load on the utilization circuit (3) that circulates the utilization fluid (Fu) in the utilization pipeline (13). Therefore, the control unit (15) can switch between the first mode (M1) and the second mode (M2) of the control valve (14) according to the rotational speed (R) of the compressor (111).

[0015] A fourth aspect of this disclosure is that, in the heat pump device (1) according to the third aspect, the control unit (15) may switch the control valve (14) to the first mode (M1) when the rotational speed (R) is in a first range, and switch the control valve (14) to the second mode (M2) when the rotational speed (R) is in a second range greater than the first range.

[0016] In accordance with the fourth point of view described above, the control unit (15) switches the control valve (14) to the second mode (M2) when the rotational speed (R) of the compressor (111) falls within the second range of any load condition in the utilization circuit (3). This allows the first heat exchanger (112) to exchange heat between the heat source fluid (Fh) and the refrigerant (Fr) at the second flow rate (F2), and the second heat exchanger (114) to exchange heat between the refrigerant (Fr) and the utilization fluid (Fu), thereby enabling the control unit (15) to handle any load condition in the utilization circuit (3). Furthermore, the control unit (15) switches the control valve (14) to the first mode (M1) when the load in the utilization circuit (3) is lower than the aforementioned arbitrary load condition, and the rotational speed (R) of the compressor (111) falls within the first range, which is smaller than the second range, resulting in a low load condition. As a result, in the first heat exchanger (112), the heat source fluid (Fh) at a first flow rate (F1), which is less than the second flow rate (F2), and the refrigerant (Fr) exchange heat, and in the second heat exchanger (114), the refrigerant (Fr) and the utilization fluid (Fu) exchange heat, thereby enabling the utilization circuit (3) to function under low load conditions. Furthermore, in the low load conditions of the utilization circuit (3), the flow rate of the heat source fluid (Fh) passing through the heat source pipe 12 decreases from the second flow rate (F2) to the first flow rate (F1), which reduces the flow rate of the heat source fluid (Fh) in the heat source circuit (2) that circulates the heat source fluid (Fh) through the heat source pipe (12), thereby improving energy efficiency.

[0017] In a fifth aspect of this disclosure, the heat pump device (1) according to any one of the first to fourth aspects further comprises a first temperature detection device (TI1) provided in the heat source pipeline (12) for detecting the inlet temperature and outlet temperature of the heat source fluid (Fh) at the inlet and outlet sides of the first heat exchanger (112), wherein the index may include the temperature difference (ΔTh) between the inlet temperature and the outlet temperature of the heat source fluid (Fh) detected by the first temperature detection device (TI1).

[0018] From the fifth point of view described above, the first temperature detection device (TI1) can measure the inlet and outlet temperatures of the heat source fluid (Fh) at the inlet and outlet sides of the first heat exchanger (112). Furthermore, the temperature difference (ΔTh) between the inlet and outlet temperatures measured by the first temperature detection device (TI1) can be used as an indicator of the load on the utilization circuit (3) that circulates the utilization fluid (Fu) through the utilization pipeline (13). When the load on this utilization circuit (3) increases, the temperature difference (ΔTh) between the inlet and outlet temperatures of the heat source fluid (Fh) at the inlet and outlet sides of the first heat exchanger (112) increases. Conversely, when the load on the utilization circuit (3) decreases, the temperature difference (ΔTh) between the inlet and outlet temperatures of the heat source fluid (Fh) at the inlet and outlet sides of the first heat exchanger (112) decreases. Therefore, if the temperature difference (ΔTh) falls within a predetermined temperature range, the control unit (15) sets the control valve (14) to the first mode (M1) and suppresses the flow rate (F) of the heat source fluid (Fh) to the first flow rate (F1). Furthermore, if the temperature difference (ΔTh) exceeds the predetermined temperature range, the control unit (15) can switch the control valve (14) to the second mode (M2) and increase the flow rate (F) of the heat source fluid (Fh) to the second flow rate (F2).

[0019] A sixth aspect of this disclosure is a heat pump device (1) according to any one of the first to fifth aspects described above, further comprising a second temperature detection device (TI2) provided in the utilization pipeline (13) for detecting the inlet temperature and outlet temperature of the utilization fluid (Fu) at the inlet and outlet sides of the second heat exchanger (114), wherein the index may include the temperature difference (ΔTu) between the inlet temperature and outlet temperature of the utilization fluid (Fu) detected by the second temperature detection device (TI2).

[0020] From the sixth point of view described above, the inlet and outlet temperatures of the utilization fluid (Fu) can be measured by the second temperature detection device (TI2) at the inlet and outlet sides of the second heat exchanger (114). Furthermore, the temperature difference (ΔTu) between the inlet and outlet temperatures measured by the second temperature detection device (TI2) can be used as an indicator of the load on the utilization circuit (3) that circulates the utilization fluid (Fu) through the utilization pipeline (13). When the load on this utilization circuit (3) increases, the temperature difference (ΔTu) between the inlet and outlet temperatures of the utilization fluid (Fu) at the inlet and outlet sides of the second heat exchanger (114) increases. Conversely, when the load on the utilization circuit (3) decreases, the temperature difference (ΔTu) between the inlet and outlet temperatures of the utilization fluid (Fu) at the inlet and outlet sides of the second heat exchanger (114) decreases. Therefore, if the temperature difference (ΔTu) falls within a predetermined temperature range, the control unit (15) sets the control valve (14) to the first mode (M1) and suppresses the flow rate (F) of the heat source fluid (Fh) to the first flow rate (F1). Furthermore, if the temperature difference (ΔTu) exceeds the predetermined temperature range, the control unit (15) can switch the control valve (14) to the second mode (M2) and increase the flow rate (F) of the heat source fluid (Fh) to the second flow rate (F2).

[0021] A seventh aspect of this disclosure is that in the heat pump device (1) according to any one of the first to sixth aspects described above, the index may include ambient temperature (T).

[0022] In accordance with the seventh point described above, the control unit (15) can switch between the first mode (M1) and the second mode (M2) of the control valve (14) using the ambient temperature (T), which correlates with the load of the utilization circuit (3) that circulates the utilization fluid (Fu) in the utilization pipeline (13), as an indicator. Specifically, during heating operation of the heat pump device (1) that heats the utilization fluid (Fu) with a refrigerant (Fr) in the second heat exchanger (114), the load of the utilization circuit (3) increases as the ambient temperature (T) decreases, and the load of the utilization circuit (3) decreases as the ambient temperature (T) increases. Also, during cooling operation of the heat pump device (1) that cools the utilization fluid (Fu) with a refrigerant (Fr) in the second heat exchanger (114), the load of the utilization circuit (3) increases as the ambient temperature (T) increases, and the load of the utilization circuit (3) decreases as the ambient temperature (T) decreases. Therefore, when the ambient temperature (T) falls within a predetermined temperature range, the control unit (15) sets the control valve (14) to the first mode (M1) and suppresses the flow rate (F) of the heat source fluid (Fh) to the first flow rate (F1). Furthermore, when the ambient temperature (T) exceeds the predetermined temperature range, the control unit (15) can switch the control valve (14) to the second mode (M2) and increase the flow rate (F) of the heat source fluid (Fh) to the second flow rate (F2).

[0023] The eighth aspect of this disclosure provides a heat pump system (HPS) comprising a heat pump device (1) according to any one of the first to seventh aspects, the system comprising: a heat source circuit (2) including a heat source section (21) that supplies the heat source fluid (Fh); a utilization circuit (3) including a utilization section (31) to which the utilization fluid (Fu) is supplied; a flow rate detection device (4) that detects the flow rate of the heat source fluid (Fh) flowing through the heat source circuit (2); a heat source pump (5) that pumps the heat source fluid (Fh) through the heat source circuit (2); and a control device (6) that controls the discharge amount of the heat source pump (5) according to the detection result of the flow rate detection device (4).

[0024] According to the eighth point described above, a heat pump system (HPS) capable of improving energy efficiency can be provided. Specifically, the control unit (15) of the heat pump device (1) constituting the heat pump system (HPS) switches the control valve (14) of the heat pump device (1) to a first mode (M1) or a second mode (M2) according to an indicator related to the load of the utilization circuit (3). As a result, a heat source fluid (Fh) at a flow rate corresponding to the load of the utilization circuit (3) can be circulated to the heat source conduit (12) of each heat pump device (1), and the flow rate of the heat source fluid (Fh) in the heat source circuit (2) that circulates the heat source fluid (Fh) in the heat source conduit (12) decreases. As a result, the control device (6) of the heat pump system (HPS) can reduce the discharge amount of the heat source pump (5) according to the detection result of the flow rate detection device (4), thereby reducing the power consumption of the heat source pump (5) and improving energy efficiency.

[0025] A circuit diagram showing an embodiment of the heat pump system (HPS) according to this disclosure. A circuit diagram of the heat pump device (1) constituting the system (HPS) in Figure 1. A block diagram showing the control unit (15) of the heat pump device (1) in Figure 2. A cross-sectional view of the control valve (14) constituting the heat pump device (1) in Figure 2. A graph explaining the mode (M) of the control valve (14) in Figure 4. A table showing the relationship between the indicators of the utilization circuit (3) in Figure 2 and the mode (M) of the control valve (14). A flow diagram of the processing of the control unit (15) constituting the heat pump device (1) in Figure 2. A circuit diagram showing an enlarged portion of the heat pump system (HPS) in Figure 1.

[0026] Hereinafter, embodiments of the heat pump device (1) and heat pump system (HPS) according to this disclosure will be described with reference to the drawings.

[0027] Figure 1 is a circuit diagram showing an embodiment of the heat pump system (HPS) according to this disclosure. Figure 2 is a circuit diagram showing an example of a heat pump device 1 that constitutes the heat pump system HPS of Figure 1.

[0028] The HPS heat pump system uses the cold energy of the heat source fluid Fh circulating in the heat source circuit 2 via the heat pump device 1 to heat or cool the utilization fluid Fu circulating in the utilization circuit 3. The cold energy of the utilization fluid Fu heated or cooled by the heat pump device 1 is used, for example, for heating, cooling, or hot water supply in detached houses, shops, apartment buildings, office buildings, commercial facilities, educational facilities, public facilities, or factories.

[0029] The heat pump system HPS of this embodiment, shown in Figures 1 and 2, comprises a heat pump device 1, a heat source circuit 2, a utilization circuit 3, a flow rate detection device 4, a heat source pump 5, and a control device 6.

[0030] A heat pump system (HPS) comprises, for example, one or more heat pump devices 1. As shown in Figure 1, the multiple heat pump devices 1 may be arranged in groups A1 and A2, such as the upper and lower floors of an apartment building or office building, and in subgroups such as A11, A12, A21, A22, etc., within each group A1 and A2. Each heat pump device 1 is installed, for example, in each household of an apartment building. Details of the heat pump devices 1 and utilization circuits 3 will be described later with reference to Figure 2.

[0031] The heat source circuit 2 includes a heat source unit 21. The heat source circuit 2 also has a supply heat source pipe 22 and a return heat source pipe 23 connected to the heat source unit 21. The heat source circuit 2 may also have a relay heat source heat exchanger 7 connected to the heat source pipes 22 and 23, as shown in the figure. In this case, the heat source circuit 2 may further have a supply heat source pipe 24 and a return heat source pipe 25 connecting the heat source heat exchanger 7 to the heat pump device 1. The heat source heat exchanger 7 is installed, for example, in relay rooms A10 and A2 provided for each group A1 and A2, such as upper floors and lower floors. The heat source heat exchanger 7 can be omitted depending on the conditions.

[0032] The heat source unit 21 uses, for example, air heat, geothermal heat, waste heat, river water, or factory wastewater as a heat source, and heats or cools the heat source fluid Fh, which is recovered via the return heat source pipeline 23 of the heat source circuit 2, to a predetermined temperature range and supplies it to the outgoing heat source pipeline 22 of the heat source circuit 2. As the heat source fluid Fh, for example, a liquid such as water or brine can be used. The heat source unit 21 includes, for example, one or more air heat source heat pump chillers. The heat source unit 21 is installed, for example, in a heat source fluid Fh supply facility A0 located away from an apartment building or office building where the heat pump device 1 is installed.

[0033] The heat source conduits 22 that go from the heat source unit 21 to each heat source heat exchanger 7 connect the heat source unit 21 to each heat source heat exchanger 7 and allow the heat source fluid Fh supplied from the heat source unit 21 and sent to each heat source heat exchanger 7 to pass through. The heat source conduits 23 that return from each heat source heat exchanger 7 to the heat source unit 21 connect each heat source heat exchanger 7 to the heat source unit 21 and allow the heat source fluid Fh that has finished heat exchange in each heat source heat exchanger 7 and is returning to the heat source unit 21 to pass through.

[0034] The heat source conduits 24 from each heat source heat exchanger 7 to each heat pump device 1 connect each heat source heat exchanger 7 to each heat pump device 1 and allow the heat source fluid Fh, which is sent out from each heat source heat exchanger 7 and supplied to each heat pump device 1, to pass through. The heat source conduits 25 from each heat pump device 1 to each heat source heat exchanger 7 connect each heat pump device 1 to each heat source heat exchanger 7 and allow the heat source fluid Fh, which has finished heat exchange in the first heat exchanger 112 of the heat pump device 1 and is returning to the heat source heat exchanger 7, to pass through.

[0035] The flow rate detection device 4 measures the flow rate of the heat source fluid Fh flowing through the heat source circuit 2. The flow rate detection device 4 is installed, for example, in the return heat source pipeline 23 connecting each heat source heat exchanger 7 to the heat source unit 21. Alternatively, the flow rate detection device 4 may be installed in the outgoing heat source pipeline 22 connecting the heat source unit 21 to each heat source heat exchanger 7. The flow rate detection device 4 is installed, for example, between the branching point of the outgoing heat source pipeline 22 closest to the heat source unit 21 and the heat source unit 21, or between the junction point of the return heat source pipeline 23 closest to the heat source unit 21 and the heat source unit 21. The flow rate detection device 4 transmits the measurement result of the flow rate of the heat source fluid Fh to the control device 6 via wireless or wired communication.

[0036] Furthermore, the flow rate detection device 4 is installed, for example, in the return heat source pipeline 25 connecting each heat pump device 1 to each heat source heat exchanger 7. Alternatively, the flow rate detection device 4 may be installed in the supply heat source pipeline 24 connecting each heat source heat exchanger 7 to each heat pump device 1. The flow rate detection device 4 is installed, for example, between the branching point of the supply heat source pipeline 24 closest to the heat source heat exchanger 7 and the heat source heat exchanger 7, or between the junction point of the return heat source pipeline 25 closest to the heat source heat exchanger 7 and the heat source heat exchanger 7. The flow rate detection device 4 transmits the measurement result of the flow rate of the heat source fluid Fh to the control device 6 via a wired or wireless communication line.

[0037] The heat source pump 5 pumps the heat source fluid Fh through the heat source circuit 2. The heat source pump 5 is installed, for example, in the supply heat source pipeline 22 connecting the heat source unit 21 and each heat source heat exchanger 7. Alternatively, the heat source pump 5 may be installed in the return heat source pipeline 23 connecting each heat source heat exchanger 7 and the heat source unit 21. The heat source pump 5 is installed, for example, between the branching point of the supply heat source pipeline 22 closest to the heat source unit 21 and the heat source unit 21, or between the junction point of the return heat source pipeline 23 closest to the heat source unit 21 and the heat source unit 21.

[0038] Furthermore, the heat source pump 5 is provided, for example, in the supply heat source pipeline 24 connecting each heat source heat exchanger 7 to each heat pump device 1. Alternatively, the heat source pump 5 may be provided in the return heat source pipeline 25 connecting each heat pump device 1 to each heat source heat exchanger 7. The heat source pump 5 is provided, for example, between the branching point of the supply heat source pipeline 24 closest to the heat source heat exchanger 7 and the heat source heat exchanger 7, or between the junction point of the return heat source pipeline 25 closest to the heat source heat exchanger 7 and the heat source heat exchanger 7.

[0039] The control device 6 includes, for example, an electronic circuit such as a CPU (Central Processing Unit), FPGA (Field Programmable Gate Array), or ASIC (Application Specific Integrated Circuit), a memory such as ROM (Read Only Memory) or RAM (Random Access Memory), and an input / output unit. The control device 6 is connected to the heat source unit 21, the flow rate detection device 4, and the heat source pump 5 via the input / output unit and a communication line.

[0040] The control device 6 performs various control operations by executing a program stored in memory using a CPU or the like, or by designing a circuit for special applications. Specifically, the control device 6 acquires the detection result of the flow detection device 4, that is, the flow rate of the heat source fluid Fh flowing through the heat source circuit 2. The control device 6 also controls the discharge amount of the heat source pump 5 according to the acquired detection result of the flow detection device 4.

[0041] As mentioned above, the heat source heat exchanger 7 is installed in each group A1, A2, such as the upper and lower floors of apartment buildings and office buildings. The heat source heat exchanger 7 exchanges heat between the heat source fluid Fh supplied from the heat source unit 21 via the heat source pipeline 22 and the heat source fluid Fh recirculated from each heat pump device 1 via the heat source pipeline 25. The method of heat exchange in the heat source heat exchanger 7 is not particularly limited.

[0042] Incidentally, each heat source heat exchanger 7, the heat source pipelines 24 and 25 between the heat source heat exchanger 7 and the heat pump device 1, and the flow rate detection device 4 and the heat source pump 5 provided in the heat source pipelines 24 and 25 may be omitted. In this case, the heat source pipelines 22 and 23 connected to the heat source section 21 can be connected to each heat pump device 1. In this case, the heat source pipeline 22 going from the heat source section 21 to each heat pump device 1 allows the heat source fluid Fh supplied from the heat source section 21 and sent to each heat pump device 1 to pass through. Further, the return heat source pipeline 23 from each heat pump device 1 to the heat source section 21 allows the heat source fluid Fh that has undergone heat exchange in the first heat exchanger 112 of each heat pump device 1 and returns to the heat source section 21 to pass through.

[0043] Next, referring to FIGS. 2 and 3, the details of the heat pump device 1 and the utilization circuit 3 will be described. FIG. 3 is a block diagram of the control unit 15 that constitutes the heat pump device 1 of FIG. 2.

[0044] The heat pump device 1 is, for example, an indoor unit installed in each household such as a detached house or an apartment house. As shown in FIG. 2, the heat pump device 1 mainly includes a refrigerant circuit 11, a heat source pipeline 12, a utilization pipeline 13, a control valve 14, and a control unit 15. Further, the heat pump device 1 may include, for example, a utilization pump 16, a branch pipeline 17, a hot water storage tank HWT, a heat exchange coil HC, a water supply pipeline 18, and a hot water supply pipeline 19.

[0045] The refrigerant circuit 11 includes a compressor 111, a first heat exchanger 112, a decompression mechanism 113, and a second heat exchanger 114, and performs a refrigeration cycle. Further, the refrigerant circuit 11 includes, for example, a refrigerant pipeline 115, a switching mechanism 116, and a check valve 117.

[0046] The compressor 111 is provided in the refrigerant pipeline 115 and compresses the refrigerant Fr filled in the refrigerant pipeline 115. The compressor 111 can be appropriately selected, for example, from a swing compressor, a scroll compressor, a screw compressor, a turbo compressor, etc., according to the application and capacity. The compressor 111 includes, for example, a motor that is housed in a casing and drives a compression mechanism, and an inverter that controls the electric power supplied to the motor.

[0047] The first heat exchanger 112 is connected to, for example, the refrigerant pipeline 115 of the refrigerant circuit 11 and the heat source pipeline 12 of the heat pump device 1 that forms part of the heat source circuit 2, and exchanges heat between the refrigerant Fr flowing through the refrigerant pipeline 115 and the heat source fluid Fh flowing through the heat source pipeline 12. The heat exchange method in the first heat exchanger 112 is not particularly limited.

[0048] The pressure reducing mechanism 113 reduces the pressure of the refrigerant Fr flowing through the refrigerant pipeline 115. The pressure reducing mechanism 113 is, for example, an expansion valve provided in the refrigerant pipeline 115 that connects the first heat exchanger 112 and the second heat exchanger 114. The pressure reducing mechanism 113 is, for example, a control valve whose opening can be changed under the control of the control unit 15.

[0049] The second heat exchanger 114 is connected to, for example, the refrigerant pipeline 115 of the refrigerant circuit 11 and the utilization pipeline 13 of the heat pump device 1 that forms part of the utilization circuit 3, and exchanges heat between the refrigerant Fr flowing through the refrigerant pipeline 115 and the utilization fluid Fu flowing through the utilization pipeline 13. The heat exchange method in the second heat exchanger 114 is not particularly limited.

[0050] The refrigerant pipeline 115 is composed of a pipe filled with the refrigerant Fr and circulating the refrigerant Fr. The refrigerant pipeline 115 may include, for example, a pipe passing through the inside of the first heat exchanger 112 and may also include a pipe passing through the inside of the second heat exchanger 114. The refrigerant pipeline 115 is provided with pressure detection devices PI on the discharge side and the suction side of the compressor 111, respectively. As shown in FIG. 3, the pressure detection device PI is connected to the control unit 15 via a wireless or wired communication line. The pressure detection device PI detects the pressures of the refrigerant Fr on the discharge side and the suction side of the compressor 111 and outputs the detection results to the control unit 15.

[0051] Also, the refrigerant pipeline 115 is provided with third temperature detection devices TI3 on the inlet side and the outlet side of the refrigerant Fr in the first heat exchanger 112, respectively. As shown in FIG. 3, the third temperature detection device TI3 is connected to the control unit 15 via a wireless or wired communication line. The third temperature detection device TI3 detects the inlet side temperature and the outlet side temperature of the refrigerant Fr on the inlet side and the outlet side of the refrigerant Fr in the first heat exchanger 112, respectively, and outputs the detection results to the control unit 15.

[0052] Furthermore, the refrigerant pipeline 115 is provided with, for example, a fourth temperature detection device TI4 on both the inlet and outlet sides of the refrigerant Fr in the second heat exchanger 114. As shown in Figure 3, the fourth temperature detection device TI4 is connected to the control unit 15 via a wireless or wired communication line. The fourth temperature detection device TI4 detects the inlet and outlet temperatures of the refrigerant Fr in the second heat exchanger 114, respectively, and outputs the detection results to the control unit 15.

[0053] The switching mechanism 116 is, for example, a four-way switching valve connected to the first heat exchanger 112 and the second heat exchanger 114 via refrigerant lines 115, and also connected to the discharge port and suction port of the compressor 111 via refrigerant lines 115. As shown in Figure 3, the switching mechanism 116 is connected to the control unit 15 via a wireless or wired communication line. The switching mechanism 116 switches between the first operating state and the second operating state of the refrigerant circuit 11 by switching the flow path, for example, under the control of the control unit 15.

[0054] In the first operating state, the refrigerant circuit 11 heats the working fluid Fu by having the second heat exchanger 114 function as a refrigerant radiator. At this time, the switching mechanism 116 switches the flow path so that the refrigerant Fr flowing out from the first heat exchanger 112 is introduced into the suction port of the compressor 111, and the refrigerant Fr discharged from the compressor 111 is introduced into the second heat exchanger 114, as shown by the solid line in Figure 2.

[0055] In the second operating state, the refrigerant circuit 11 cools the working fluid Fu by having the second heat exchanger 114 function as a refrigerant evaporator. At this time, the switching mechanism 116 switches the flow path so that the refrigerant Fr flowing out of the second heat exchanger 114 is introduced into the suction port of the compressor 111, and the refrigerant Fr discharged from the compressor 111 is introduced into the first heat exchanger 112, as shown by the dashed line in Figure 2.

[0056] The check valve 117 is installed in the refrigerant pipeline 115 that connects the discharge port of the compressor 111 and the switching mechanism 116. The check valve 117 allows the refrigerant Fr flowing from the compressor 111 to the switching mechanism 116 to pass through, and blocks the reverse flow of refrigerant Fr from the switching mechanism 116 to the compressor 111.

[0057] The heat source conduit 12 allows the heat source fluid Fh circulating in the heat source circuit 2 to pass through the first heat exchanger 112. The heat source conduit 12 includes a supply pipe connecting the supply heat source conduit 24 (or heat source conduit 22) of the heat source circuit 2 to the inlet of the heat source fluid Fh in the first heat exchanger 112. The heat source conduit 12 also includes a return pipe connecting the outlet of the heat source fluid Fh in the first heat exchanger 112 to the return heat source conduit 25 (or heat source conduit 23) of the heat source circuit 2. The heat source conduit 12 may also include a pipe passing through the inside of the first heat exchanger 112. The heat source conduit 12 constitutes a part of the heat source circuit 2 that circulates the heat source fluid Fh.

[0058] Furthermore, the heat source pipeline 12 is equipped with first temperature detection devices TI1 on both the inlet and outlet sides of the heat source fluid Fh of the first heat exchanger 112. As shown in Figure 3, the first temperature detection devices TI1 are connected to the control unit 15 via a wireless or wired communication line. The first temperature detection devices TI1 measure the inlet and outlet temperatures of the heat source fluid Fh at the inlet and outlet sides of the first heat exchanger 112 and output the measurement results to the control unit 15. The first temperature detection devices TI1 are provided in the supply and return pipes of the heat source pipeline 12. In addition, the heat source pipeline 12 is equipped with a control valve 14.

[0059] The control valve 14 is installed, for example, in the supply piping of the heat source pipeline 12. The control valve 14 includes a differential pressure adjustment mechanism that uses the differential pressure of the heat source fluid Fh to maintain the flow rate of the heat source fluid Fh within a certain range relative to a predetermined pressure range. The control valve 14 is also called, for example, a pressure independent control valve (PICV), a pressure regulating valve, or a constant flow valve. As shown in Figure 3, the control valve 14 is connected to the control unit 15 via a wired or wireless communication line and controlled by the control unit 15. Details of the control valve 14 and the control unit 15 will be described later with reference to Figures 4 to 6.

[0060] Furthermore, on-off valves are provided at the end of the supply heat source pipeline 24 (or heat source pipeline 22) of the heat source circuit 2, and at the end of the supply piping of the heat source pipeline 12 connected to that end. Similarly, on-off valves are provided at the end of the return heat source pipeline 25 (or heat source pipeline 23) of the heat source circuit 2, and at the end of the return piping of the heat source pipeline 12 connected to that end.

[0061] The utilization circuit 3, which constitutes part of the heat pump system (HPS), includes a utilization section 31 to which the utilization fluid Fu is supplied. The utilization circuit 3 is also connected to the utilization line 13 of the heat pump device 1 and includes a utilization line 32 that circulates the utilization fluid Fu through the utilization circuit 3. As the utilization fluid Fu circulated through the utilization circuit 3, for example, a liquid such as water or brine can be used.

[0062] The utilization section 31 is located in the middle of the utilization pipeline 32, and the utilization fluid Fu is supplied through the utilization pipeline 32. The utilization section 31 includes, for example, radiators 311 and underfloor heating and cooling systems 312 installed in the rooms of each household. The utilization pipeline 32 includes supply pipes connected to the inlets of the utilization fluid Fu in each utilization section 31, and return pipes connected to the outlets of the utilization fluid Fu in each utilization section 31. An on / off valve is provided at the end of the utilization pipeline 32 connected to the utilization pipeline 13 of the heat pump device 1.

[0063] The utilization line 13 of the heat pump device 1 is connected to the utilization line 32 of the utilization circuit 3 and constitutes a part of the utilization circuit 3. The utilization line 13 passes the utilization fluid Fu circulating in the utilization circuit 3 to the second heat exchanger 114 of the refrigerant circuit 11. That is, the utilization circuit 3 may include the utilization line 13 of the heat pump device 1 and the second heat exchanger 114.

[0064] The utilization pipeline 13 of the heat pump device 1 includes a supply pipe connecting the outlet of the utilization fluid Fu of the second heat exchanger 114 to the supply pipe of the utilization pipeline 32 that constitutes the utilization circuit 3. The heat source pipeline 12 also includes a return pipe connecting the return pipe of the utilization pipeline 32 that constitutes the utilization circuit 3 to the inlet of the second heat exchanger 114. Furthermore, the utilization pipeline 13 may also include a pipe that passes through the inside of the second heat exchanger 114.

[0065] The supply piping of utilization pipeline 13 supplies the utilization fluid Fu from the second heat exchanger 114 to each utilization section 31 via the supply piping of utilization pipeline 32. The return piping of utilization pipeline 13 recirculates the utilization fluid Fu from each utilization section 31 to the second heat exchanger 114 via the return piping of utilization pipeline 32. The piping of utilization pipeline 13 that passes inside the second heat exchanger 114 allows the utilization fluid Fu to pass through the inside of the second heat exchanger 114, and heat exchange occurs between the utilization fluid Fu and the refrigerant Fr of the refrigerant circuit 11.

[0066] The utilization pipeline 13 includes a second temperature detection device TI2 that detects the inlet and outlet temperatures of the utilization fluid Fu at the inlet and outlet sides of the utilization fluid Fu of the second heat exchanger 114. The second temperature detection device TI2 is provided in the supply and return piping of the utilization pipeline 13, respectively. In addition, an on-off valve and a three-way valve Vt are provided in the supply piping of the utilization pipeline 13 from the upstream side to the downstream side of the utilization fluid Fu flow, and an on-off valve and a utilization pump 16 are provided in the return piping of the utilization pipeline 13 from the upstream side to the downstream side of the utilization fluid Fu flow.

[0067] The utilization pump 16 pumps the utilization fluid Fu and circulates it through the utilization circuit 3, which includes the utilization pipeline 13 and the second heat exchanger 114 of the heat pump device 1. The utilization pump 16 is connected to the control unit 15, for example, via a wired or wireless communication line, and the discharge amount is controlled by the control unit 15.

[0068] The three-way valve Vt is installed in the supply piping of the utilization pipeline 13 and connected to the branch pipeline 17. The three-way valve Vt has a first opening connected to the second heat exchanger 114 via the utilization pipeline 13, a second opening connected to the utilization pipeline 32 of the utilization circuit 3 via the utilization pipeline 13, and a third opening connected to the branch pipeline 17.

[0069] Furthermore, the three-way valve Vt has a valve body that can switch between a first state and a second state, and a drive unit that drives the valve body to switch between the first state and the second state. The drive unit is connected to the control unit 15 via a wired or wireless communication line, as shown in Figure 3, for example, and is controlled by the control unit 15 to switch between the first state and the second state of the three-way valve Vt.

[0070] The first state of the three-way valve Vt is a state in which the valve body connects the first opening and the second opening, blocking the space between the first opening and the third opening. In this first state, the utilization fluid Fu that flows from the second heat exchanger 114 to the first opening of the three-way valve Vt via the utilization pipeline 13 passes through the three-way valve Vt and flows into the utilization pipeline 32 of the utilization circuit 3 via the utilization pipeline 13 connected to the second opening of the three-way valve Vt.

[0071] The second state of the three-way valve Vt is a state in which the valve body blocks the connection between the first and second openings, while connecting the first and third openings. In this second state, the utilization fluid Fu that flows from the second heat exchanger 114 to the first opening of the three-way valve Vt via the utilization pipeline 13 passes through the three-way valve Vt and flows into the branch pipeline 17 connected to the third opening of the three-way valve Vt.

[0072] The branch pipeline 17 has an upstream pipe connecting the third opening of the three-way valve Vt to the inlet of the heat exchange coil HC housed in the hot water storage tank HWT, and a downstream pipe connecting the outlet of the heat exchange coil HC to the utilization pipeline 13. When the three-way valve Vt is switched to the second state, the branch pipeline 17 allows the utilization fluid Fu to pass through the heat exchange coil HC. The utilization section 31 of the utilization circuit 3 may include, for example, the heat exchange coil HC.

[0073] The hot water storage tank HWT houses a heat exchange coil HC inside. The hot water storage tank HWT is connected to a water supply pipe 18 and a hot water supply pipe 19. The utilization circuit 3 also includes, for example, a water supply pipe 33 and a hot water supply pipe 34. The water supply pipe 33 and the hot water supply pipe 34 of the utilization circuit 3 are connected to the water supply pipe 18 and the hot water supply pipe 19 of the heat pump device 1 at ends where on-off valves are provided.

[0074] The water supply pipeline 33 of the utilization circuit 3 supplies tap water TW to the hot water storage tank HWT via the water supply pipeline 18 of the heat pump device 1. The hot water storage tank HWT stores the tap water TW supplied via the water supply pipeline 18. The tap water TW stored in the hot water storage tank HWT is heated by heat exchange with the utilization fluid Fu flowing through the heat exchange coil HC, becoming hot water HW. The hot water HW in the hot water storage tank HWT is supplied to equipment that uses hot water HW, such as showers Sh, via the hot water supply pipeline 19 of the heat pump device 1 and the hot water supply pipeline 34 of the utilization circuit 3.

[0075] The control unit 15, similar to the control device 6 of a heat pump system (HPS), includes electronic circuits such as a CPU, memory such as ROM or RAM, and an input / output unit. It implements various functions by executing programs stored in memory using the CPU. The control unit 15 is connected to various parts of the heat pump device 1 via the input / output unit and wired or wireless communication lines. Specifically, as shown in Figure 3, the control unit 15 is connected to, for example, the compressor 111, the pressure reducing mechanism 113, the switching mechanism 116, the control valve 14, the utilization pump 16, the three-way valve Vt, the pressure detection device PI, the first temperature detection device TI1, the second temperature detection device TI2, the third temperature detection device TI3, and the fourth temperature detection device TI4.

[0076] The control unit 15 controls the rotational speed and capacity of the compressor 111, for example, by controlling the inverter that supplies power to the motor of the compressor 111. The control unit 15 also controls the pressure reducing mechanism 113, for example, to change the opening degree of the pressure reducing mechanism 113. The control unit 15 also controls the switching mechanism 116, for example, to switch between the first operating state and the second operating state of the refrigerant circuit 11. The control unit 15 also controls the discharge amount of the utilization pump 16, for example, according to an indicator related to the load of the utilization circuit 3. The control unit 15 also controls the three-way valve Vt, for example, to switch between the first state and the second state of the three-way valve Vt.

[0077] Next, the details of the control valve 14 and the control unit 15 will be described with reference to Figures 4 to 6.

[0078] Figure 4 is a schematic cross-sectional view showing an example of a control valve 14 that constitutes the heat pump device 1 in Figure 2. Figure 5 is a graph illustrating an example of mode M in the control valve 14 in Figure 4. Figure 6 is a table showing an example of the relationship between an index related to the load of the utilization circuit 3 in Figure 2 and mode M of the control valve 14.

[0079] As described above, the control valve 14 is installed in the heat source pipeline 12 of the heat pump device 1. The control valve 14 includes a differential pressure adjustment mechanism 14A that uses the differential pressure ΔPv of the heat source fluid Fh to maintain the flow rate F of the heat source fluid Fh within a certain range for a predetermined pressure range. The control valve 14 also includes an adjustment mechanism 14B that changes the flow path width Wf.

[0080] Specifically, the control valve 14 includes, for example, a body 141, a bonnet 142, a stem 143, a diaphragm 144, an automatic valve body 145, a spring 146, a valve seat 147, a valve body 148, an actuation unit 149, and pressure piping 14p.

[0081] The body 141 has an inlet and outlet for the heat source fluid Fh at both ends and is open at the top. The bonnet 142 is attached to the top of the body 141 and closes the top of the body 141. The stem 143 is supported by the bonnet 142 so as to be movable in the axial direction.

[0082] The diaphragm 144 is positioned between the body 141 and the bonnet 142, with its peripheral edge fixed between the body 141 and the bonnet 142. A pressure chamber is formed between the diaphragm 144 and the bonnet 142, through which the primary pressure Pv1 of the heat source fluid Fh at the inlet side of the control valve 14 is introduced by the pressure piping 14p.

[0083] Specifically, the body 141 has an opening 141a on the inlet side of the control valve 14, and the bonnet 142 has an opening 142a that communicates with the pressure chamber between the diaphragm 144 and the bonnet 142. The pressure piping 14p connects the opening 141a of the body 141 and the opening 142a of the bonnet 142, and introduces the heat source fluid Fh of the primary pressure Pv1 at the inlet side of the control valve 14 into the pressure chamber between the diaphragm 144 and the bonnet 142.

[0084] The automatic valve body 145 is positioned adjacent to the diaphragm 144 on the opposite side of the pressure chamber between the bonnet 142 and the diaphragm 144, and is supported within the body 141 so as to be movable in the axial direction of the stem 143. A spring 146 is positioned between the automatic valve body 145 and the valve seat 147, biasing the automatic valve body 145 toward the diaphragm 144. The valve seat 147 is fixed within the body 141 and forms a passage for the heat source fluid Fh between itself and the automatic valve body 145.

[0085] The valve body 148 is attached to the tip of the stem 143 and forms a flow path for the heat source fluid Fh between it and the valve seat 147. The drive unit 149 is controlled by the control unit 15 and adjusts the flow path width Wf of the heat source fluid Fh between the valve seat 147 and the valve body 148 by moving the stem 143 in the axial direction.

[0086] In the example shown in Figure 4, the differential pressure adjustment mechanism 14A, which uses the differential pressure of the heat source fluid Fh to maintain the flow rate of the heat source fluid Fh within a certain range relative to a predetermined pressure range, includes a diaphragm 144, an automatic valve body 145, and a spring 146.

[0087] Specifically, the primary pressure Pv1 of the heat source fluid Fh at the inlet side of the control valve 14 is introduced into the pressure chamber between the bonnet 142 and the diaphragm 144 via the pressure piping 14p, acting on the diaphragm 144 and pushing the automatic valve body 145 downward toward the valve seat 147. The automatic valve body 145 is also pushed upward toward the diaphragm 144 by the intermediate pressure Pv2 of the heat source fluid Fh that has passed through the flow path between the valve seat 147 and the valve body 148, and by the elastic force of the spring 146.

[0088] The automatic valve body 145 moves to a position where the primary pressure Pv1 of the heat source fluid Fh that pushes the automatic valve body 145 down balances the intermediate pressure Pv2 of the heat source fluid Fh that pushes the automatic valve body 145 up, and the elastic force of the spring 146, thereby forming a flow path for the heat source fluid Fh between it and the valve seat 147. As a result, the pressure of the heat source fluid Fh at the outlet side of the control valve 14 converges to the outlet pressure Pv3.

[0089] Even if the primary pressure Pv1 of the heat source fluid Fh increases and the flow rate of the heat source fluid Fh increases, the propagation of the primary pressure Pv1 acting on the diaphragm 144 via the pressure pipe 14p takes precedence, pushing down the automatic valve body 145. As a result, the automatic valve body 145 moves toward the valve seat 147 until the primary pressure Pv1 acting on the diaphragm 144 balances out the intermediate pressure Pv2 and the elastic force of the spring 146, thereby narrowing the flow path between the automatic valve body 145 and the valve seat 147.

[0090] Thus, the differential pressure adjustment mechanism 14A maintains the flow rate of the heat source fluid Fh within a certain range for a predetermined pressure range by utilizing the differential pressure ΔPv between the primary pressure Pv1 and the intermediate pressure Pv2 of the heat source fluid Fh. This flow rate adjustment function by the differential pressure adjustment mechanism 14A utilizes the differential pressure ΔPv between the primary pressure Pv1 and the intermediate pressure Pv2 of the heat source fluid Fh, which is generated by the flow path width Wf between the valve seat 147 and the valve body 148, i.e., the opening degree of the valve body 148. Therefore, the flow rate of the heat source fluid Fh passing through the control valve 14 is independent of both fluctuations in the primary pressure Pv1 on the inlet side of the control valve 14 and fluctuations in the outlet pressure Pv3 on the outlet side of the control valve 14, and is independent of the primary pressure Pv1 and the outlet pressure Pv3.

[0091] Furthermore, in the example shown in Figure 4, the adjustment mechanism 14B that changes the flow path width Wf between the valve seat 147 and the valve body 148, i.e., the opening degree of the valve body 148, includes a stem 143, a valve seat 147, a valve body 148, and a drive unit 149. The control valve 14 can be changed to multiple modes with different flow rates for a predetermined pressure range of the heat source fluid Fh by changing the flow path width Wf using the adjustment mechanism 14B.

[0092] Specifically, the control valve 14 can change its mode M between a first mode M1 and a second mode M2, as shown in Figure 5, by changing the flow path width Wf using the adjustment mechanism 14B. In the graph shown in Figure 5, the horizontal axis represents the differential pressure ΔPv between the primary pressure Pv1 and the intermediate pressure Pv2, and the vertical axis represents the flow rate F of the heat source fluid Fh passing through the control valve 14.

[0093] In the first mode M1, the flow rate F of the heat source fluid Fh is adjusted to a certain range near the first flow rate F1, with respect to a predetermined pressure range PvR from a minimum value ΔPv_min to a maximum value ΔPv_max of the differential pressure ΔPv of the heat source fluid Fh. In the second mode M2, the flow rate F of the heat source fluid Fh is adjusted to a certain range near the second flow rate F2, which is greater than the first flow rate F1, with respect to a predetermined pressure range PvR of the heat source fluid Fh.

[0094] The control unit 15 controls the adjustment mechanism 14B according to an indicator of the load on the utilization circuit 3 that circulates the utilization fluid Fu in the utilization pipeline 13, and switches between the first mode M1 and the second mode M2. The load on the utilization circuit 3 is, for example, the heating and cooling load or the hot water supply load in the utilization unit 31. Specifically, for example, the load on the utilization circuit 3 increases as the amount of heat emitted or absorbed by the radiator 311 or the underfloor heating and cooling 312 installed in the room increases. Also, the load on the utilization circuit 3 increases as the temperature of the hot water HW heated by the heat exchange coil HC is increased or the amount of hot water HW supplied is increased.

[0095] Here, the indicators related to the load of the utilization circuit 3 include, for example, the rotational speed R of the compressor 111. That is, there is a positive correlation between the load of the utilization circuit 3 and the rotational speed of the compressor 111, and as the load of the utilization circuit 3 increases, it becomes necessary to increase the rotational speed of the compressor 111. Therefore, the control unit 15 may switch between the first mode M1 and the second mode M2 ​​by controlling the adjustment mechanism 14B according to the rotational speed R of the compressor 111.

[0096] Specifically, as shown in the table in Figure 6, the control unit 15 switches the mode M of the control valve 14 to the first mode M1 when, for example, the rotational speed R of the compressor 111 is in a first range where it exceeds 10 [rpm] and is 20 [rpm] or less. As a result, the flow rate F of the heat source fluid Fh passing through the control valve 14 is adjusted to the first flow rate F1 in a predetermined pressure range PvR, as shown in Figure 5.

[0097] Furthermore, as shown in the table in Figure 6, the control unit 15 switches the mode M of the control valve 14 to the second mode M2 ​​when, for example, the rotational speed R of the compressor 111 exceeds 20 [rpm] and is 30 [rpm] or less, and is in a second range which is greater than the first range. As a result, the flow rate F of the heat source fluid Fh passing through the control valve 14 is adjusted to a second flow rate F2 which is greater than the first flow rate F1 in a predetermined pressure range PvR, as shown in Figure 5. Note that the rotational speed R of the compressor 111 in the first and second ranges is illustrative and not particularly limited.

[0098] Furthermore, in the example shown in Figure 6, the control valve 14 can be changed to multiple modes M in which the flow rate F differs for a predetermined pressure range PvR of the heat source fluid Fh, in addition to the first mode M1 and second mode M2 ​​mentioned above, by changing the flow path width Wf using the adjustment mechanism 14B. Specifically, the control valve 14 can be changed to any one of the eighth modes M8 mentioned above, from the first mode M1 to the eighth mode M8, by changing the flow path width Wf using the adjustment mechanism 14B according to an indicator related to the load of the utilization circuit 3, including the rotational speed R of the compressor 111.

[0099] As the mode M of the control valve 14 is changed from the first mode M1 to the eighth mode M8, the flow rate F of the heat source fluid Fh passing through the control valve 14 increases stepwise from the first flow rate F1 to the eighth flow rate F8, reaching a maximum in the eighth mode M8. The number of modes M of the control valve 14 is not particularly limited, as long as there are two or more stages.

[0100] Furthermore, the control valve 14 may be changed to a fully closed mode M0 by adjusting the flow path width Wf to zero using the adjustment mechanism 14B when the rotational speed R of the compressor 111 is 0 [rpm], thereby reducing the flow rate F of the heat source fluid Fh passing through the control valve 14 to zero. Alternatively, the control unit 15 may continuously adjust the flow path width Wf using the adjustment mechanism 14B according to an indicator related to the load of the utilization circuit 3.

[0101] Furthermore, in the example shown in Figure 6, the control valve 14 can be changed to transient mode TR by changing the flow path width Wf using the adjustment mechanism 14B, thereby adjusting the flow rate F of the heat source fluid Fh passing through the control valve 14 to a transient flow rate Ftr that is smaller than the first flow rate F1. In this case, the control unit 15 switches the control valve 14 to transient mode TR in a transient state where the differential pressure ΔP of the refrigerant Fr between the discharge side and the suction side of the compressor 111 is less than or equal to a predetermined value Ptr.

[0102] In this case, the control unit 15 calculates the differential pressure ΔP of the refrigerant Fr between the discharge side and the suction side of the compressor 111 based on the detection result of the pressure detection device PI, which detects the pressure of the refrigerant Fr on the discharge side and the suction side of the compressor 111. The transient state of the compressor 111 is, for example, the period from the start of the compressor 111 to steady-state operation, or a state in which some abnormality occurs during the operation of the compressor 111 and the rotational speed R of the compressor 111 falls below a predetermined value.

[0103] Furthermore, the indicator for the load of the utilization circuit 3 may include the temperature difference ΔTh between the inlet temperature and the outlet temperature of the heat source fluid Fh, as shown in Figure 6. This temperature difference ΔTh of the heat source fluid Fh is calculated by the control unit 15 based on the detection results of the first temperature detection device TI1, which is provided in the heat source pipeline 12 shown in Figure 2 and detects the inlet temperature and outlet temperature of the heat source fluid Fh at the inlet and outlet sides of the first heat exchanger 112.

[0104] Furthermore, the indicator for the load of the utilization circuit 3 may include the temperature difference ΔTu between the inlet temperature and the outlet temperature of the utilization fluid Fu, as shown in Figure 6. This temperature difference ΔTu of the utilization fluid Fu is calculated by the control unit 15 based on the detection results of the second temperature detection device TI2, which is provided in the utilization pipeline 13 shown in Figure 2 and detects the inlet temperature and outlet temperature of the utilization fluid Fu at the inlet and outlet sides of the second heat exchanger 114.

[0105] Furthermore, the indicators related to the load of the utilization circuit 3 may include the ambient temperature T, as shown in Figure 6. The ambient temperature T is obtained, for example, by the control unit 15 downloading regional weather information stored on a server via a communication line. The heat pump device 1 may also be connected to a thermometer capable of detecting the ambient temperature, for example.

[0106] Next, the operation of the heat pump device 1 and the heat pump system HPS of this embodiment will be explained with reference to Figures 7 and 8. Figure 7 is a flowchart illustrating the processing of the control unit 15 that constitutes the heat pump device 1 in Figure 2. Figure 8 is a circuit diagram showing an enlarged portion of the heat pump system HPS in Figure 1.

[0107] As shown in Figure 1, the heat pump system HPS uses a control device 6 to drive the heat source pump 5 and circulate the heat source fluid Fh supplied from the heat source unit 21 to the heat source circuit 2. As shown in Figure 2, the heat pump device 1 passes the heat source fluid Fh to the first heat exchanger 112 of the refrigerant circuit 11 via a heat source pipeline 12 connected to the outgoing heat source pipeline 24 and the return heat source pipeline 25 of the heat source circuit 2.

[0108] Furthermore, the heat pump device 1 uses the control unit 15 to drive the motor of the compressor 111 to compress the refrigerant Fr, and the control unit 15 switches the flow path of the switching mechanism 116 to circulate the refrigerant Fr in the direction indicated by the solid arrow. As a result, the heat pump device 1 uses the first heat exchanger 112 as an evaporator, and performs heating operation by transferring heat from the heat source fluid Fh to the refrigerant Fr through heat exchange between the refrigerant Fr and the heat source fluid Fh in the first heat exchanger 112.

[0109] Furthermore, the heat pump device 1 drives the utilization pump 16 via the control unit 15, and passes the utilization fluid Fu to the second heat exchanger 114 via the utilization pipeline 13, which is connected to the utilization pipeline 32 of the utilization circuit 3 and constitutes part of the utilization circuit 3. In this way, the heat pump device 1 makes the first heat exchanger 112 function as a heat radiator and exchanges heat between the refrigerant Fr and the utilization fluid Fu in the second heat exchanger 114, thereby transferring heat from the refrigerant Fr to the utilization fluid Fu.

[0110] The utilization fluid Fu, whose temperature has risen due to heat exchange with the refrigerant Fr in the second heat exchanger 114, is supplied to the utilization section 31 via the utilization pipeline 13 and utilization pipeline 32, where it dissipates heat into the room air, etc. The utilization fluid Fu, whose temperature has decreased after dissipating heat in the utilization section 31, is recirculated to the second heat exchanger 114 via the utilization pipeline 32 and utilization pipeline 13, where its temperature rises again due to heat exchange with the refrigerant Fr.

[0111] Furthermore, the control unit 15 of the heat pump device 1 controls the three-way valve Vt to switch from the first state to the second state, thereby performing hot water storage operation. In hot water storage operation, the working fluid Fu, whose temperature has risen due to heat exchange with the refrigerant Fr in the second heat exchanger 114, passes through the heat exchange coil HC via the three-way valve Vt and the branch pipe 17, and exchanges heat with the tap water TW stored in the hot water storage tank HWT.

[0112] In hot water storage operation, the tap water TW in the hot water storage tank HWT becomes hot water HW through heat exchange with the utilization fluid Fu passing through the heat exchange coil HC, and is supplied to showers Sh, etc., via the hot water supply pipes 19 and 34. In this way, in hot water storage operation, the utilization fluid Fu is passed through the heat exchange coil HC, and the tap water TW in the hot water storage tank HWT is heated through heat exchange with the utilization fluid Fu to generate hot water HW. In hot water storage operation, hot water supply of hot water HW from the hot water storage tank HWT to hot water utilization equipment such as showers Sh may occur simultaneously, or it may not occur. The utilization fluid Fu, whose temperature has decreased by radiating heat to the tap water TW after passing through the heat exchange coil HC, returns to the second heat exchanger 114 via the branch pipe 17 and utilization pipe 13, and its temperature rises again through heat exchange with the refrigerant Fr.

[0113] Furthermore, the control unit 15 of the heat pump device 1 can also circulate the refrigerant Fr in the direction indicated by the dashed arrow by switching the flow path of the switching mechanism 116. As a result, the heat pump device 1 can also perform cooling operation by having the first heat exchanger 112 function as a heat radiator and the second heat exchanger 114 function as an evaporator to cool the working fluid Fu.

[0114] The control unit 15 of the heat pump device 1 executes the processing flow shown in Figure 7 during the heating operation, hot water storage operation, or cooling operation. When the control unit 15 starts the processing flow shown in Figure 7, it executes a process P1 that determines whether the indicator related to the load of the utilization circuit 3 satisfies condition 1.

[0115] Here, the indicators related to the load of the utilization circuit 3 can be, for example, one or more of the following: the rotational speed R of the compressor 111 shown in Figure 6, the temperature difference ΔTh between the inlet and outlet temperatures of the heat source fluid Fh, the ambient temperature T, or the temperature difference ΔTu between the inlet and outlet temperatures of the utilization fluid Fu. Also, condition 1 can be, for example, the condition for switching the mode M of the control valve 14 shown in Figure 6 to the first mode M1.

[0116] In process P1, when the control unit 15 determines that the indicator for the load of the utilization circuit 3 satisfies condition 1 (YES), it executes process P2 to switch the control valve 14 to first mode M1, thereby ending the process flow shown in Figure 7. As a result, the flow path width Wf is changed by the adjustment mechanism 14B shown in Figure 4, and as shown in Figure 5, the flow rate F of the heat source fluid Fh passing through the control valve 14 is adjusted to the first flow rate F1 for a predetermined pressure range PvR.

[0117] On the other hand, in process P1, if the control unit 15 determines that the indicator for the load of the utilization circuit 3 does not satisfy condition 1 (NO), it executes process P3 to determine whether or not the indicator for the load of the utilization circuit 3 satisfies condition 2.

[0118] Here, the indicators related to the load of the utilization circuit 3 can be, for example, one or more of the following: the rotational speed R of the compressor 111 shown in Figure 6, the temperature difference ΔTh between the inlet and outlet temperatures of the heat source fluid Fh, the ambient temperature T, or the temperature difference ΔTu between the inlet and outlet temperatures of the utilization fluid Fu. Also, condition 2 can be, for example, the condition for switching the mode M of the control valve 14 shown in Figure 6 to the second mode M2.

[0119] In process P3, when the control unit 15 determines that the indicator for the load of the utilization circuit 3 satisfies condition 2 (YES), it executes process P4 to switch the control valve 14 to second mode M2, thereby ending the process flow shown in Figure 7. As a result, the flow path width Wf is changed by the adjustment mechanism 14B shown in Figure 4, and as shown in Figure 5, the flow rate F of the heat source fluid Fh passing through the control valve 14 for a predetermined pressure range PvR is adjusted to a second flow rate F2 which is greater than the first flow rate F1.

[0120] On the other hand, in process P3, if the control unit 15 determines that the indicator for the load of the utilization circuit 3 does not satisfy condition 2 (NO), it executes process P5 to determine whether the indicator for the load of the utilization circuit 3 satisfies the transient condition. Here, the indicator for the load of the utilization circuit 3 can be, for example, the differential pressure ΔP between the discharge side and the suction side of the compressor 111 shown in Figure 6. The transient condition can be, for example, the condition for switching the mode M of the control valve 14 shown in Figure 6 to transient mode TR.

[0121] In process P5, when the control unit 15 determines that the load indicator of the utilization circuit 3 satisfies the transient condition (YES), it executes process P6 to switch the control valve 14 to transient mode TR, thereby ending the process flow shown in Figure 7. As a result, the flow path width Wf is changed by the adjustment mechanism 14B shown in Figure 4, and as shown in Figure 5, the flow rate F of the heat source fluid Fh passing through the control valve 14 for a predetermined pressure range PvR is adjusted to a transient flow rate Ftr that is smaller than the first flow rate F1.

[0122] The control unit 15 may perform the same determination process as process P1 and the same mode M switching process as process P2 for all conditions from the third mode M3 to the eighth mode M8 of the control valve 14 shown in Figure 6.

[0123] As described above, the heat pump device 1 of this embodiment includes a refrigerant circuit 11, a heat source pipeline 12, a utilization pipeline 13, a control valve 14, and a control unit 15. The refrigerant circuit 11 includes a compressor 111 for compressing the refrigerant Fr, a first heat exchanger 112 for exchanging heat between the refrigerant Fr and the heat source fluid Fh, a pressure reducing mechanism 113 for reducing the pressure of the refrigerant Fr, and a second heat exchanger 114 for exchanging heat between the refrigerant Fr and the utilization fluid Fu, and performs a refrigeration cycle. The heat source pipeline 12 allows the heat source fluid Fh to pass through the second heat exchanger 114. The utilization pipeline 13 allows the utilization fluid Fu to pass through the second heat exchanger 114. The control valve 14 is provided in the heat source pipeline 12 and includes a differential pressure adjustment mechanism 14A that uses the differential pressure ΔPv of the heat source fluid Fh to maintain the flow rate F of the heat source fluid Fh within a certain range relative to a predetermined pressure range PvR. The control unit 15 controls the control valve 14. The control valve 14 also includes an adjustment mechanism 14B that changes the flow path width Wf, and by changing the flow path width Wf using the adjustment mechanism 14B, it is possible to switch between a first mode M1 and a second mode M2. In the first mode M1, the flow rate F of the heat source fluid Fh for a predetermined pressure range PvR is adjusted to a first flow rate F1, and in the second mode M2, the flow rate F of the heat source fluid Fh for a predetermined pressure range PvR is adjusted to a second flow rate F2 which is greater than the first flow rate F1. The control unit 15 then switches between the first mode M1 and the second mode M2 ​​by controlling the adjustment mechanism 14B according to an indicator related to the load of the utilization circuit 3 that circulates the utilization fluid Fu in the utilization pipeline 13.

[0124] With this configuration, for example, the control valve 14 can be switched between the first mode M1 and the second mode M2 ​​according to an index related to the load of the utilization circuit 3, which is correlated with the amount of heat dissipated or absorbed by the utilization fluid Fu in the utilization section 31 of the utilization circuit 3. As a result, for example, as shown in Figure 8, the flow rate F of the heat source fluid Fh flowing through the heat source conduit 12 of each heat pump device 1 is adjusted by the control valve 14 to the first flow rate F1 or the second flow rate F2 according to the index related to the load of the utilization circuit 3 in each heat pump device 1. Therefore, with the heat pump device 1 of this embodiment, compared to the case in which the heat source fluid Fh at the second flow rate F2 is constantly passing through the heat source conduit 12, the amount of heat source fluid Fh discharged by the heat source pump 5 of the heat pump system HPS can be reduced, thereby improving energy saving.

[0125] Furthermore, in the heat pump device 1 of this embodiment, the control valve 14 can be changed to transient mode TR by changing the flow path width Wf using the adjustment mechanism 14B, thereby adjusting the flow rate F of the heat source fluid Fh to a transient flow rate Ftr that is smaller than the first flow rate F1 for a predetermined pressure range PvR. In addition, the control unit 15 switches the control valve 14 to transient mode TR in a transient state where the differential pressure ΔP of the refrigerant Fr between the discharge side and the suction side of the compressor 111 is less than or equal to a predetermined value Ptr.

[0126] With this configuration, for example, if an abnormality occurs between the start-up of the compressor 111 and steady-state operation, or during the operation of the compressor 111, and the differential pressure ΔP of the refrigerant Fr between the discharge side and the suction side of the compressor 111 falls below a predetermined value Ptr, the control unit 15 determines that a transient state has occurred. In this transient state, the control unit 15 switches the control valve 14 to transient mode TR. As a result, the flow rate F of the heat source fluid Fh flowing through the heat source pipeline 12 is adjusted by the adjustment mechanism 14B to a transient flow rate Ftr that is smaller than the first flow rate F1. This suppresses problems caused by excessive heat source fluid Fh passing through the first heat exchanger 112 during the transient state of the compressor 111. Furthermore, in the heat source circuit 2 that circulates the heat source fluid Fh in the heat source pipeline 12, the amount of heat source fluid Fh discharged by the heat source pump 5 can be reduced, improving energy efficiency.

[0127] Furthermore, in the heat pump device 1 of this embodiment, the indicator relating to the load of the utilization circuit 3 may include the rotational speed R of the compressor 111.

[0128] With this configuration, the rotational speed R of the compressor 111 can be used as an indicator of the load on the utilization circuit 3 that circulates the utilization fluid Fu in the utilization pipeline 13. Specifically, the control unit 15 increases the rotational speed of the compressor 111 when the load on the utilization circuit 3 increases. Therefore, the control unit 15 can switch between the first mode M1 and the second mode M2 ​​of the control valve 14 according to the rotational speed R of the compressor 111.

[0129] Furthermore, in the heat pump device 1 of this embodiment, the control unit 15 switches the control valve 14 to the first mode M1 when the rotational speed R of the compressor 111 is within the first range, and switches the control valve 14 to the second mode M2 ​​when the rotational speed R of the compressor 111 is within the second range which is greater than the first range.

[0130] With this configuration, the control unit 15 switches the control valve 14 to the second mode M2 ​​when the load state of the utilization circuit 3 is in a second range where the rotational speed R of the compressor 111 exceeds 20 [rpm] and is 30 [rpm] or less, as shown in Figure 6. This allows the load state of the utilization circuit 3 to be addressed by the heat exchange between the heat source fluid Fh of the second flow rate F2 and the refrigerant Fr in the first heat exchanger 112, and the heat exchange between the refrigerant Fr and the utilization fluid Fu in the second heat exchanger 114. Furthermore, the control unit 15 switches the control valve 14 to the first mode M1 when the load state of the utilization circuit 3 is lower than the aforementioned load state and the rotational speed R of the compressor 111 is in a first range where it exceeds 10 [rpm] and is 20 [rpm] or less, which is smaller than the second range. As a result, in the first heat exchanger 112, the heat source fluid Fh at a first flow rate F1, which is less than the second flow rate F2, exchanges heat with the refrigerant Fr, and in the second heat exchanger 114, the refrigerant Fr exchanges heat with the utilization fluid Fu, thereby enabling the utilization circuit 3 to handle low load conditions. Furthermore, in the low load condition of the utilization circuit 3, the flow rate of the heat source fluid Fh passing through the heat source pipeline 12 decreases from the second flow rate F2 to the first flow rate F1, which reduces the discharge amount of the heat source fluid Fh by the heat source pump 5 in the heat source circuit 2 that circulates the heat source fluid Fh in the heat source pipeline 12, thereby improving energy efficiency.

[0131] Furthermore, the heat pump device 1 of this embodiment is provided in the heat source pipeline 12 and further includes a first temperature detection device TI1 that detects the inlet temperature and outlet temperature of the heat source fluid Fh at the inlet and outlet sides of the first heat exchanger 112. The indicator for the load of the utilization circuit 3 may include the temperature difference ΔTh between the inlet temperature and the outlet temperature of the heat source fluid Fh detected by the first temperature detection device TI1.

[0132] With this configuration, the first temperature detection device TI1 can measure the inlet and outlet temperatures of the heat source fluid Fh at the inlet and outlet sides of the first heat exchanger 112. Furthermore, the temperature difference ΔTh between the inlet and outlet temperatures measured by the first temperature detection device TI1 can be used as an indicator of the load on the utilization circuit 3 that circulates the utilization fluid Fu in the utilization pipeline 13. When the load on this utilization circuit 3 increases, the temperature difference ΔTh between the inlet and outlet temperatures of the heat source fluid Fh at the inlet and outlet sides of the first heat exchanger 112 increases. Conversely, when the load on the utilization circuit 3 decreases, the temperature difference ΔTh between the inlet and outlet temperatures of the heat source fluid Fh at the inlet and outlet sides of the first heat exchanger 112 decreases. Therefore, as shown in Figure 6, when this temperature difference ΔTh falls within a predetermined temperature range, the control unit 15 sets the control valve 14 to the first mode M1 and suppresses the flow rate F of the heat source fluid Fh to the first flow rate F1. Furthermore, if this temperature difference ΔTh exceeds a predetermined temperature range, the control unit 15 can switch the control valve 14 to the second mode M2 ​​and increase the flow rate F of the heat source fluid Fh to the second flow rate F2.

[0133] Furthermore, the heat pump device 1 of this embodiment is provided in the utilization pipeline 13 and further includes a second temperature detection device TI2 that detects the inlet and outlet temperatures of the utilization fluid Fu at the inlet and outlet sides of the second heat exchanger 114. The indicator for the load of the utilization circuit 3 may include the temperature difference ΔTu between the inlet and outlet temperatures of the utilization fluid Fu detected by the second temperature detection device TI2.

[0134] With this configuration, the second temperature detection device TI2 can measure the inlet and outlet temperatures of the utilization fluid Fu at the inlet and outlet sides of the second heat exchanger 114. Furthermore, the temperature difference ΔTu between the inlet and outlet temperatures measured by the second temperature detection device TI2 can be used as an indicator of the load on the utilization circuit 3 that circulates the utilization fluid Fu in the utilization pipeline 13. When the load on the utilization circuit 3 increases, the temperature difference ΔTu between the inlet and outlet temperatures of the utilization fluid Fu at the inlet and outlet sides of the second heat exchanger 114 increases. Conversely, when the load on the utilization circuit 3 decreases, the temperature difference ΔTu between the inlet and outlet temperatures of the utilization fluid Fu at the inlet and outlet sides of the second heat exchanger 114 decreases. Therefore, as shown in Figure 6, when this temperature difference ΔTu falls within a predetermined temperature range, the control unit 15 sets the control valve 14 to the first mode M1 and suppresses the flow rate F of the heat source fluid Fh to the first flow rate F1. Furthermore, if this temperature difference ΔTu exceeds a predetermined temperature range, the control unit 15 can switch the control valve 14 to the second mode M2 ​​and increase the flow rate F of the heat source fluid Fh to the second flow rate F2.

[0135] Furthermore, in the heat pump device 1 of this embodiment, the indicator related to the load of the utilization circuit 3 may include the ambient temperature T.

[0136] With this configuration, the control unit 15 can switch between the first mode M1 and the second mode M2 ​​of the control valve 14 using the ambient temperature T, which correlates with the load of the utilization circuit 3 that circulates the utilization fluid Fu in the utilization pipeline 13, as an indicator. Specifically, during heating operation of the heat pump device 1, which heats the utilization fluid Fu with the refrigerant Fr in the second heat exchanger 114, the load of the utilization circuit 3 increases as the ambient temperature T decreases, and decreases as the ambient temperature T increases. Also, during cooling operation of the heat pump device 1, which cools the utilization fluid Fu with the refrigerant Fr in the second heat exchanger 114, the load of the utilization circuit 3 increases as the ambient temperature T increases, and decreases as the ambient temperature T decreases. Therefore, as shown in Figure 6, when the ambient temperature T falls within a predetermined temperature range, the control unit 15 sets the control valve 14 to the first mode M1 and suppresses the flow rate F of the heat source fluid Fh to the first flow rate F1. Furthermore, if the ambient temperature T exceeds a predetermined temperature range, the control unit 15 can switch the control valve 14 to the second mode M2 ​​and increase the flow rate F of the heat source fluid Fh to the second flow rate F2.

[0137] Furthermore, the heat pump system HPS of this embodiment includes the heat pump device 1 described above. The heat pump system HPS also includes a heat source circuit 2 including a heat source unit 21 that supplies a heat source fluid Fh, a utilization circuit 3 including a utilization unit 31 to which a utilization fluid Fu is supplied, and a flow rate detection device 4 that detects the flow rate of the heat source fluid Fh flowing through the heat source circuit 2. The heat pump system HPS also includes a heat source pump 5 that pumps the heat source fluid Fh through the heat source circuit 2, and a control device 6 that controls the discharge amount of the heat source pump 5 according to the detection result of the flow rate detection device 4.

[0138] This configuration makes it possible to provide an HPS heat pump system that can improve energy efficiency. Specifically, the control unit 15 of the heat pump device 1 that constitutes the HPS heat pump system switches the control valve 14 of the heat pump device 1 to either the first mode M1 or the second mode M2 ​​according to an indicator related to the load of the utilization circuit 3. As a result, a heat source fluid Fh at a flow rate corresponding to the load of the utilization circuit 3 can be circulated to the heat source pipeline 12 of each heat pump device 1, and the flow rate of the heat source fluid Fh in the heat source circuit 2 that circulates the heat source fluid Fh in the heat source pipeline 12 decreases. As a result, the control device 6 of the HPS heat pump system can reduce the discharge amount of the heat source pump 5 according to the detection result of the flow rate detection device 4, thereby reducing the power consumption of the heat source pump 5 and improving energy efficiency.

[0139] Preferred embodiments and variations of the present disclosure have been described in detail above. However, the present disclosure is not limited to the embodiments and variations described above. Various modifications or substitutions may be applied to the embodiments and variations described above without departing from the scope of the present disclosure. Furthermore, features described separately can be combined as long as no technical inconsistencies arise.

[0140] 1 Heat pump device 11 Refrigerant circuit 111 Compressor 112 First heat exchanger 113 Pressure reducing mechanism 114 Second heat exchanger 12 Heat source pipeline 13 Utilization pipeline 14 Control valve 14A Differential pressure adjustment mechanism 14B Adjustment mechanism 15 Control unit 2 Heat source circuit 21 Heat source unit 3 Utilization circuit 31 Utilization unit 4 Flow rate detection device 5 Heat source pump 6 Control device F Flow rate F1 First flow rate F2 Second flow rate Fh Heat source fluid Fr Refrigerant Ftr Transient flow rate Fu Utilization fluid HPS Heat pump system M1 First mode M2 ​​Second mode Ptr Determined value PvR Determined pressure range R Rotation speed T Ambient temperature TI1 First temperature detection device TI2 Second temperature detection device TR Transient mode Wf ​​Flow path width ΔP Differential pressure ΔPv Differential pressure ΔTh Temperature difference ΔTu Temperature difference

Claims

1. A refrigerant circuit (11) that performs a refrigeration cycle, including a compressor (111) for compressing a refrigerant (Fr), a first heat exchanger (112) for exchanging heat between the refrigerant (Fr) and a heat source fluid (Fh), a pressure reducing mechanism (113) for reducing the pressure of the refrigerant (Fr), and a second heat exchanger (114) for exchanging heat between the refrigerant (Fr) and a utilization fluid (Fu); a heat source pipeline (12) for passing the heat source fluid (Fh) through the first heat exchanger (112); a utilization pipeline (13) for passing the utilization fluid (Fu) through the second heat exchanger (114); and a control valve (14) provided in the heat source pipeline (12), including a differential pressure adjustment mechanism (14A) that uses the differential pressure (ΔPv) of the heat source fluid (Fh) to maintain the flow rate (F) of the heat source fluid (Fh) within a predetermined pressure range (PvR) within a certain range. A heat pump device (1) comprising: a control unit (15) that controls the control valve (14); the control valve (14) includes an adjustment mechanism (14B) that changes the flow path width (Wf); the adjustment mechanism (14B) allows switching between a first mode (M1) in which the flow rate (F) of the heat source fluid (Fh) for the predetermined pressure range (PvR) is adjusted to a first flow rate (F1); and a second mode (M2) in which the flow rate (F) of the heat source fluid (Fh) for the predetermined pressure range (PvR) is adjusted to a second flow rate (F2) that is greater than the first flow rate (F1); and the control unit (15) controls the adjustment mechanism (14B) according to an indicator of the load of the utilization circuit (3) that circulates the utilization fluid (Fu) in the utilization pipeline (13) to switch between the first mode (M1) and the second mode (M2).

2. The control valve (14) can be changed to a transient mode (TR) in which the flow rate (F) of the heat source fluid (Fh) for the predetermined pressure range (PvR) is adjusted to a transient flow rate (Ftr) that is smaller than the first flow rate (F1) by changing the flow path width (Wf) by the adjustment mechanism (14B), and the control unit (15) switches the control valve (14) to the transient mode (TR) in a transient state in which the differential pressure (ΔP) of the refrigerant (Fr) between the discharge side and the suction side of the compressor (111) is less than or equal to a predetermined value (Ptr), the heat pump device (1) according to claim 1.

3. The heat pump device (1) according to claim 1, wherein the indicator includes the rotational speed (R) of the compressor (111).

4. The heat pump device (1) according to claim 3, wherein the control unit (15) switches the control valve (14) to the first mode (M1) when the rotational speed (R) is in a first range, and switches the control valve (14) to the second mode (M2) when the rotational speed (R) is in a second range greater than the first range.

5. The heat pump device (1) according to claim 1, further comprising a first temperature detection device (TI1) provided in the heat source pipeline (12) for detecting the inlet temperature and outlet temperature of the heat source fluid (Fh) at the inlet and outlet sides of the first heat exchanger (112), wherein the index includes the temperature difference (ΔTh) between the inlet temperature and the outlet temperature of the heat source fluid (Fh) detected by the first temperature detection device (TI1).

6. The heat pump device (1) according to claim 1, further comprising a second temperature detection device (TI2) provided in the utilization pipeline (13) for detecting the inlet temperature and outlet temperature of the utilization fluid (Fu) at the inlet and outlet sides of the second heat exchanger (114), wherein the index includes the temperature difference (ΔTu) between the inlet temperature and the outlet temperature of the utilization fluid (Fu) detected by the second temperature detection device (TI2).

7. The heat pump device (1) according to claim 1, wherein the indicator includes ambient temperature (T).

8. A heat pump system (HPS) comprising a heat pump device (1) according to any one of claims 1 to 7, the system comprising: a heat source circuit (2) including a heat source unit (21) for supplying the heat source fluid (Fh); a utilization circuit (3) including a utilization unit (31) to which the utilization fluid (Fu) is supplied; a flow rate detection device (4) for detecting the flow rate of the heat source fluid (Fh) flowing through the heat source circuit (2); a heat source pump (5) for pressurizing and pumping the heat source fluid (Fh) through the heat source circuit (2); and a control device (6) for controlling the discharge amount of the heat source pump (5) according to the detection result of the flow rate detection device (4).

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