EP4650672A1

EP4650672A1 - Heat pump apparatus

Info

Publication number: EP4650672A1
Application number: EP25173562.7A
Authority: EP
Inventors: Hayato Matsumoto; Ko Inagaki
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2024-05-13
Filing date: 2025-04-30
Publication date: 2025-11-19
Also published as: JP2025172609A

Abstract

The present disclosure provides a heat pump apparatus that easily reduces erroneous measurement of a flow rate of a heating medium.The heat pump apparatus according to the present disclosure includes: a refrigerant circuit including a utilization-side heat exchanger, which exchanges heat between a refrigerant and a heating medium, inside a housing; and a heating medium pipe through which the heating medium flowing out from the utilization-side heat exchanger flows, a flow meter is provided inside the housing to be connected to an outlet of the heating medium pipe and to measure a flow rate of the heating medium, and the heating medium pipe is formed with an outlet-side straight portion that extends in a straight line to the flow meter.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a heat pump apparatus.

Description of the Related Art

International Publication No. WO 2018-047265 discloses a heat pump apparatus that prevents ignition of a flammable refrigerant. The heat pump apparatus includes a refrigerant circuit that uses a flammable refrigerant, a heating medium circuit, and a refrigerant release valve that is used as an air vent valve or a pressure relief valve for the heating medium circuit, the refrigerant release valve is provided outside a housing of an outdoor unit and releases a refrigerant mixed in the heating medium.

SUMMARY OF THE INVENTION

The present disclosure provides a heat pump apparatus capable of preventing erroneous measurement of a flow rate of a heating medium with ease.
A heat pump apparatus according to the present disclosure includes: a refrigerant circuit including a utilization-side heat exchanger, which exchanges heat between a refrigerant and a heating medium, inside a housing; and a heating medium pipe through which the heating medium flowing out from the utilization-side heat exchanger flows, a flow meter is provided inside the housing to be connected to an outlet of the heating medium pipe and to measure a flow rate of the heating medium, and the heating medium pipe is formed with an outlet-side straight portion that extends in a straight line to the flow meter.
The heat pump apparatus according to the present disclosure can easily reduce turbulence in a flow of a heating medium that reaches a flow meter. Therefore, it is possible to easily prevent erroneous measurement of a flow rate of the heating medium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a refrigerant circuit and a water circuit of a hot water heater according to a first embodiment;
FIG. 2 is a perspective view illustrating an inside of an outdoor unit;
FIG. 3 is a front view illustrating the inside of the outdoor unit; and
FIG. 4 is a right side view illustrating the inside of the outdoor unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(Findings on which the Present Disclosure is Based)

At the time when the inventors come up with the present disclosure, there is a technique in which a heat pump apparatus includes a refrigerant circuit including a utilization-side heat exchanger inside a housing, thereby allowing a heating medium, which exchanges heat with a refrigerant in the utilization-side heat exchanger, to flow outside the housing. For this reason, in the industry, it has been common to design products in which a housing in a heat pump apparatus houses the whole refrigeration circuit and a heating medium pipe through which a heating medium flows. Under such circumstances, the inventors have found that there is a problem that the flow meter may erroneously measure depending on the shape of the heating medium pipe when a flow meter for measuring a flow rate of the heating medium is installed inside the housing of the heat pump apparatus, and have come up with the subject matter of the present disclosure to solve the problem.
The present disclosure provides a heat pump apparatus that easily prevents erroneous measurement of a flow rate of a heating medium.
An embodiment will be described in detail with reference to the drawings. However, more detailed description than necessary may not be given. For example, detailed description of already well-known matters or duplicate redundant description of substantially the same component may not be given. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art.
It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(First Embodiment)

A first embodiment will be described below with reference to the drawings.

[1-1. Configuration]

[1-1-1. Configuration of Refrigeration Circuit]

FIG. 1 is a diagram illustrating a refrigerant circuit R of a hot water heater 1 according to a first embodiment and a water circuit W. The hot water heater 1 includes an outdoor unit 10 that is mainly installed outdoors, and an indoor unit 70 that is mainly installed in a space to be air-conditioned such as an indoor space. The outdoor unit 10 is an example of a "heat pump apparatus" in the present disclosure.
A hot water supply heater is a device that performs heating of a space to be air-conditioned by flowing water heated by the outdoor unit 10 to an indoor heat exchanger 71 of the indoor unit 70. The hot water supply heater of the present embodiment can also perform cooling operation by flowing water cooled by the outdoor unit 10 to the indoor heat exchanger 71. In FIG. 1, flows of refrigerant and water during cooling operation of the hot water heater are indicated by arrows. The water is an example of a "heating medium" in the present disclosure.
The outdoor unit 10 is provided with the refrigerant circuit R. The refrigerant circuit R includes a compressor 12, air heat exchanger 14, an expansion valve 16, and a plate water-refrigerant heat exchanger 30.
The compressor 12 is a device that sucks a refrigerant to compress and discharge the refrigerant. In the outdoor unit 10, a flow channel switching mechanism 13 is connected to a discharge side and suction side of the compressor 12. The flow channel switching mechanism 13 switches an inflow destination of the refrigerant discharged to the compressor 12 between the air heat exchanger 14 and a plate water-refrigerant heat exchanger 30, and causes the heat exchangers 14 and 30 of the inflow destination to function as condensers. In addition, the flow channel switching mechanism 13 causes the refrigerant, which has passed through an evaporator of the heat exchangers 14 and 30 to be sucked into the compressor 12. The flow channel switching mechanism 13 is, for example, a four-way valve.
The air heat exchanger 14 is a heat exchanger that exchanges heat between the inside refrigerant and outside air. The air heat exchanger 14 is a fin-tube heat exchanger, for example. The outdoor unit 10 is provided with an outdoor air-blowing fan 15 that blows outside air into the air heat exchanger 14. In the present embodiment, the outdoor air-blowing fan 15 is an axial fan.
The plate water-refrigerant heat exchanger 30 is a plate heat exchanger that exchanges heat between the refrigerant flowing inside and water. The plate water-refrigerant heat exchanger 30 is an example of a "utilization-side heat exchanger" in the present disclosure.
The air heat exchanger 14 and the plate water-refrigerant heat exchanger 30 are connected to each other through the expansion valve 16. The expansion valve 16 is a valve that reduces a pressure of the refrigerant flowing in from the condenser of each of the heat exchangers 14 and 30 to make the refrigerant in a gas-liquid two phase state and allows the refrigerant to flow into the evaporator of each of the heat exchangers 14 and 30. In the present embodiment, an opening degree of the expansion valve 16 can be adjusted by electronic control, and the flow rate of the refrigerant is adjusted by the change of the opening degree.
As illustrated in FIG. 1, the refrigerant circuit R formed by the connection of the compressor 12, the expansion valve 16, each of the heat exchangers 14 and 30, and the like is housed inside a housing 11 of the outdoor unit 10.
As illustrated in FIG. 1, the hot water supply heater 1 is formed with the water circuit W. The water circuit W is a circuit that circulates water as a heating medium between the plate water-refrigerant heat exchanger 30 of the outdoor unit 10 and the indoor heat exchanger 71 of the indoor unit 70. The indoor heat exchanger 71 is a heat exchanger that exchanges heat between the inside water and the air in the space to be air-conditioned. The indoor unit 70 includes an indoor air-blowing fan 73 that flows air into the indoor heat exchanger 71. The indoor unit 70 drives the indoor air-blowing fan 73 to pass the air in the space to be air-conditioned through the indoor heat exchanger 71 and then return the air to the space to be air-conditioned, thereby performing air-conditioning on the space to be air-conditioned.
The water circuit W connects the indoor unit 70 and the outdoor unit 10, and includes two connecting pipes 75 and 77 through which water flows as a heating medium. Further, the water circuit W includes a circulation pump 21 provided inside the outdoor unit 10. The circulation pump 21 is driven to suck water from the connecting pipe 75 and causes the sucked water to flow toward the plate water-refrigerant heat exchanger 30. In this way, the water circulates inside the water circuit W.

[1-1-2. Arrangement of Components in Heat pump apparatus]

FIG. 2 is a perspective view illustrating the inside of the outdoor unit 10. FIG. 3 is a front view illustrating the inside of the outdoor unit 10. In each of the drawings of the present disclosure, the housing 11 is not partially illustrated in order to show the inside of the outdoor unit 10. In the drawings, a symbol X indicates a left side of the outdoor unit 10, a symbol Y indicates a front side of the outdoor unit 10, and a symbol Z indicates an upper side.
As illustrated in FIGS. 2 and 3, the housing 11 of the outdoor unit 10 has a substantially rectangular parallelepiped shape. The housing 11 is formed therein with an air-blowing fan room 17 which is a space partitioned to a left side of a partition plate 19 and a machine room 18 which is a space partitioned to a right side of the partition plate 19. The partition plate 19 is formed of a sheet metal and is provided in a posture that is substantially orthogonal in a left-right direction.
The housing 11 includes a bottom plate 11a made of a sheet metal and forming a lower surface of the housing 11. The housing 11 includes a front panel 11b that forms a front surface of the air-blowing fan room 17. An opening is formed in the front panel 11b. Further, the housing 11 includes a top panel (not illustrated). The top panel forms an upper surface of the housing 11. The housing 11 also includes side panels (not illustrated) that cover the machine room 18 from front, right, and rear sides.
The air-blowing fan room 17 is provided with the air heat exchanger 14 and the outdoor air-blowing fan 15. The air heat exchanger 14 is provided on a right surface and a rear surface of the air-blowing fan room 17. Specifically, in the housing 11, the right surface and the rear surface of the air-blowing fan room 17 are open, and the air heat exchanger 14 is exposed to the outside of the housing 11 through the opening.
The outdoor air-blowing fan 15 blows the air inside the outdoor unit 10 forward through the opening of the front panel 11b, thereby sucking outside air through the air heat exchanger 14 and exchanging heat between the outside air and the refrigerant inside the air heat exchanger 14. In the present embodiment, the outdoor unit 10 is described as an example in which one outdoor air-blowing fan 15 is provided in the air-blowing fan room 17, but the number of outdoor air-blowing fans 15 in the outdoor unit 10 is not particularly limited.

[1-1-3. Configuration of Machine Room]

The machine room 18 is a space in which the above-described compressor 12, the flow channel switching mechanism 13, the expansion valve 16, and the plate water-refrigerant heat exchanger 30 are provided.
FIG. 4 is a right side view illustrating the inside of the outdoor unit 10.
As illustrated in FIG. 4, the plate water-refrigerant heat exchanger 30 is provided in a position biased toward the front side inside the machine room 18. In other words, the plate water-refrigerant heat exchanger 30 is disposed at a position biased toward the front side inside the housing 11. In more detail, as illustrated in FIG. 4, the whole of the plate water-refrigerant heat exchanger 30 is located forward of a center C in a front-rear direction of the housing 11.
As illustrated in FIG. 4, the plate water-refrigerant heat exchanger 30 is provided with a first refrigerant-side connection port 31 and a second refrigerant-side connection port 32. Each of the refrigerant-side connection ports 31 and 32 is an opening that communicates with the flow channel through which the refrigerant flows in the plate water-refrigerant heat exchanger 30. The first refrigerant-side connection port 31 is formed at a lower end on the front side of the right surface of the plate water-refrigerant heat exchanger 30. The first refrigerant-side connection port 31 is connected to the expansion valve 16 through a refrigerant pipe. The second refrigerant-side connection port 32 is formed above the first refrigerant-side connection port 31, on the right surface of the plate water-refrigerant heat exchanger 30. The second refrigerant-side connection port 32 is connected to the flow channel switching mechanism 13 through a refrigerant pipe.
The plate water-refrigerant heat exchanger 30 is provided with a first water-side connection port 34 and a second water-side connection port 35. Each of the water-side connection ports 34 and 35 is an opening that communicates with the flow channel through which the water flows in the plate water-refrigerant heat exchanger 30. The first water-side connection port 34 is provided at the lower end on the rear side of the right surface of the plate water-refrigerant heat exchanger 30. The second water-side connection port 35 is provided above the first water-side connection port 34, on the right surface of the plate water-refrigerant heat exchanger 30.
The first water-side connection port 34 is connected to a discharge side of the circulation pump 21 that circulates water. In other words, the first water-side connection port 34 is an entrance on a water side in the plate water-refrigerant heat exchanger 30. A suction side of the circulation pump 21 is provided with an inlet-side connection valve 22 that protrudes rearward to the outside of the outdoor unit 10 and can be connected to the connecting pipe 75 outside the outdoor unit 10.
The second water-side connection port 35 is a water-side outlet in the plate water-refrigerant heat exchanger 30. The second water-side connection port 35 is connected to a gas-liquid separator 23 that removes gas from the water flowing out from the plate water-refrigerant heat exchanger 30. The second water-side connection port 35 corresponds to an "outlet of the heating medium in the utilization-side heat exchanger" in the present disclosure.
The gas-liquid separator 23 is formed with a liquid-side outlet 24 that is an outlet for water after gas is removed. The liquid-side outlet 24 opens downward. Further, the liquid-side outlet 24 is located below the second water-side connection port 35. Furthermore, the liquid-side outlet 24 is located rearward of a rear end 30a of the plate water-refrigerant heat exchanger 30. In the present embodiment, specifically, the liquid-side outlet 24 is located rearward of the center C in the front-rear direction of the housing 11.
A water pipe 40 is connected to the liquid-side outlet 24. The water pipe 40 is a pipe through which water heat-exchanged with the refrigerant in the plate water-refrigerant heat exchanger 30 flows. In the present embodiment, the water passing through the gas-liquid separator 23 flows into the water pipe 40. For this reason, gas is unlikely to be mixed into the water flowing into the water pipe 40. In the present embodiment, the whole of the water pipe 40 is approximately located below the liquid-side outlet 24. The water pipe 40 corresponds to a "heating medium pipe" in the present disclosure.
The water pipe 40 is formed with an inlet portion 41. The inlet portion 41 is connected to the liquid-side outlet 24 of the gas-liquid separator 23 from below. The inlet portion 41 extends downward from the liquid-side outlet 24 of the gas-liquid separator 23 and curves forward. In the present embodiment, the whole of the inlet portion 41 is located rearward of the rear end 30a of the plate water-refrigerant heat exchanger 30.
The water pipe 40 is formed with an inlet-side straight portion 43. The inlet-side straight portion 43 is formed in a straight line that is inclined downward toward the front. An upper end of the inlet-side straight portion 43 is coupled to a lower end of the inlet portion 41. A front end of the inlet-side straight portion 43 is located forward of the rear end 30a of the plate water-refrigerant heat exchanger 30.
The water pipe 40 is formed with a curved portion 45. The curved portion 45 is curved rearward from the lower end of the inlet-side straight portion 43. In the present embodiment, the whole of the curved portion 45 is located forward of the rear end 30a of the plate water-refrigerant heat exchanger 30.
The water pipe 40 is formed with an outlet-side straight portion 47. The outlet-side straight portion 47 is the most downstream portion of the water pipe 40. The outlet-side straight portion 47 extends forward from a lower end of the curved portion 45.
The outlet-side straight portion 47 is formed in a straight line. Specifically, the outlet-side straight portion 47 extends horizontally in a straight line. More specifically, the outlet-side straight portion 47 extends straight in the front-rear direction.
In the present embodiment, the outlet-side straight portion 47 is configured to extend long in the front-rear direction over a range from a position forward of the rear end 30a of the plate water-refrigerant heat exchanger 30 to a position rearward of the center C in the front-rear direction of the housing 11.
A flow meter 25 is connected to an outlet 49 of the water pipe 40, that is, a rear end of the outlet-side straight portion 47. The flow meter 25 measures the flow rate of water circulating through the water circuit W. The flow meter 25 is located inside the housing 11. In the present embodiment, the flow meter 25 is an electromagnetic flow meter. The flow meter 25 may not be an electromagnetic flow meter. For example, an example of the flow meter 25 may include any flow meter such as an ultrasonic flow meter or a thermal flow meter.
Specifically, the flow meter 25 includes a measuring tube 26. The measuring tube 26 is a portion in the flow meter 25 through which water flows. In the present embodiment, the flow meter 25 measures the flow rate of water inside the measuring tube 26.
The measuring tube 26 is formed in a straight line. In the present embodiment, the measuring tube 26 is disposed to extend in the front-rear direction. The measuring tube 26 is connected to the outlet 49 of the water pipe 40. Specifically, the measuring tube 26 is connected to the outlet 49 such that a central axis of the measuring tube 26 approximately coincides with a central axis of the outlet-side straight portion 47.
An outlet-side connection valve 27 is connected to an outlet side of the measuring tube 26, that is, a rear end of the measuring tube 26. The outlet-side connection valve 27 is a valve that can be connected to the connecting pipe 77. The outlet-side connection valve 27 protrudes rearward from the rear surface of the housing 11. In the present embodiment, a flow channel inside the outlet-side connection valve 27 extends in the front-rear direction. The outlet-side connection valve 27 is connected to the measuring tube 26 such that a central axis of the flow channel inside the outlet-side connection valve 27 approximately coincides with a central axis of the measuring tube 26.
In other words, the outlet-side straight portion 47 of the water pipe 40, the measuring tube 26 of the water pipe 40, and the flow channel of the outlet-side connection valve 27 can form a substantially straight flow channel extending in the front-rear direction.

[1-2. Operation]

An operation of the hot water heater 1 configured as described above will be described below.
When the hot water heater 1 performs a heating operation or a cooling operation, the compressor 12 is driven to circulate the refrigerant in the refrigerant circuit R, and the plate water-refrigerant heat exchanger 30 functions as an evaporator for refrigerant or a condenser for refrigerant. Thus, the water in the water circuit W is cooled or heated.
The water in the water circuit W is circulated by driving of the circulation pump 21. The water discharged by the circulation pump 21 flows into the plate water-refrigerant heat exchanger 30 through the first water-side connection port 34, and is heated or cooled. The water heated or cooled in the plate water-refrigerant heat exchanger 30 flows into the gas-liquid separator 23 through the second water-side connection port 35. The water flowing into the gas-liquid separator 23 flows into the water pipe 40 through the liquid-side outlet 24 after removal of the mixed gas.
The water flowing into the water pipe 40 flows through the inlet portion 41, the inlet-side straight portion 43, the curved portion 45, and the outlet-side straight portion 47 of the water pipe 40.
Here, the outlet-side straight portion 47 is located below the second water-side connection port 35 which is an outlet for the water flowing through the plate water-refrigerant heat exchanger 30. In the present embodiment, the outlet-side straight portion 47 is located even lower than the liquid-side outlet 24 which is located below the second water-side connection port 35. Therefore, pressure loss can be easily reduced which is caused by the difference in height from the second water-side connection port 35 and the liquid-side outlet 24 to the outlet-side straight portion 47. In the present embodiment, since the almost whole of the water pipe 40 is located below the liquid-side outlet 24 of the gas-liquid separator 23, the pressure loss due to the difference in height can be reduced, compared to, for example, a case where a part of the water pipe 40 is located above the liquid-side outlet 24.
The water flowing through the outlet-side straight portion 47 flows to the flow meter 25 through the outlet 49 of the water pipe 40. Here, since the outlet-side straight portion 47 extends in a straight line to the flow meter 25, turbulence in the water flowing through the outlet-side straight portion 47 can be easily prevented. For this reason, it is possible to prevent the turbulence in the water flowing into flow meter 25. Particularly, in the present embodiment, the water flowing through the water pipe 40 flows downward toward the front through the inlet-side straight portion 43, and then flows through the outlet-side straight portion 47 that extends in the front-rear direction over the range from the position forward of the rear end 30a of the plate water-refrigerant heat exchanger 30 to the position rearward of the center C in the front-rear direction of the housing 11. Thereby, the water easily flows through the outlet-side straight portion 47 over a long distance, and the turbulence in the water flowing into the flow meter 25 can be easily reduced.
The water flowing into the measuring tube 26 of the flow meter 25 flows rearward inside the measuring tube 26. As described above, the turbulence in the water flowing into the measuring tube 26 is not easily caused, and thus the flow meter 25 is less likely to erroneously measure the flow rate of the water. In addition, since the water, from which the gas is removed by the gas-liquid separator 23, flows into the flow meter 25, the flow meter 25 is less likely to erroneously measure the flow rate of the water.
The water passing through the measuring tube 26 flows into the connecting pipe 77 through the outlet-side connection valve 27. As described above, since the outlet-side straight portion 47, the measuring tube 26 of the flow meter 25, and the outlet-side connection valve 27 are provided in a straight line in the front-rear direction, a force of the water flowing into the connecting pipe 77 is not easily weakened.
The water flowing through the connecting pipe 77 flows into the indoor unit 70, and exchanges heat with the air in the space to be air-conditioned in the indoor heat exchanger 71. Thus, the air in the space to be air-conditioned is heated or cooled, and the space to be air-conditioned is heated or cooled.

[1-3. Effects]

In the present embodiment, as described above, the outdoor unit 10 includes, inside the housing 11, the refrigerant circuit R including the plate water-refrigerant heat exchanger 30 that exchanges heat between the refrigerant and the water, and the water pipe 40 through which the water flowing out from the plate water-refrigerant heat exchanger 30 flows; the flow meter 25 is provided inside the housing 11 to be connected to the outlet 49 of the water pipe 40 and to measure the flow rate of the water; and the water pipe is formed with the outlet-side straight portion 47 that extends in a straight line to the flow meter 25.
Thus, it is possible to easily reduce the turbulence in the flow of the water that reaches the flow meter 25. For this reason, it is possible to easily prevent the erroneous measurement of the flow rate of the water.
As in the present embodiment, the outdoor unit 10 may be provided with the gas-liquid separator 23 that removes the gas from the water flowing out from the plate water-refrigerant heat exchanger 30, and the water pipe may be connected to the liquid-side outlet 24 of the gas-liquid separator 23.
Thus, even when the water contains gas, it is possible to easily remove the gas from the water before the water reaches the flow meter. For this reason, it is possible to easily prevent the erroneous measurement of the flow rate of the water.
As in the present embodiment, the outlet-side straight portion 47 may extend horizontally, the outlet-side connection valve 27 is provided on the outlet side of the flow meter 25 to protrude outward from the housing 11, and the outlet-side straight portion 47, the flow meter 25, and the outlet-side connection valve 27 may be aligned in a straight line.
Thus, the heating medium flowing through the outlet-side straight portion 47 of the water pipe 40 can reach the outlet-side connection valve 27 outside the housing without bending of the flow channel. For this reason, it is possible to easily reduce resistance to the flow of the water.
As in the present embodiment, the outlet-side straight portion 47 may be located below the second water-side connection port 35, which is the outlet for water in the plate water-refrigerant heat exchanger 30.
Thus, it is possible to easily reduce the pressure loss of the water due to the difference in height between the second water-side connection port 35, which is the outlet of the water in the plate water-refrigerant heat exchanger 30 and the outlet-side straight portion 47. For this reason, it is possible to easily reduce energy required to make the water flow.
Particularly, in the present embodiment, the whole of the water pipe 40 is located below the second water-side connection port 35. For this reason, it is possible to easily prevent an increase in the energy required to make the water flow.
As in the present embodiment, the outdoor unit 10 may be configured in which: the plate water-refrigerant heat exchanger 30 is provided forward of the center C in the front-rear direction inside the housing 11; the liquid-side outlet 24 of the gas-liquid separator 23 is located rearward of the plate water-refrigerant heat exchanger 30; the outlet-side straight portion 47 extends in the front-rear direction from the position forward of the rear end 30a of the plate water-refrigerant heat exchanger 30 to the position rearward of the center C in the front-rear direction inside the housing 11; and the flow meter 25 is located rearward of the outlet-side straight portion 47.
Thus, it is possible to make the outlet-side straight portion 47 as long as possible in the front-rear direction, and to easily reduce the turbulence in the flow of the water that reaches the flow meter 25. For this reason, it is possible to easily prevent the erroneous measurement of the flow rate of the water.

(Other Embodiments)

As described above, the first embodiment has been described to exemplify the technique disclosed in the present application. However, the technique in the present disclosure is not limited to the embodiment, and is also applicable to embodiments in which modifications, replacements, additions, omissions, or the like are made. In addition, new embodiments can be made by combinations of respective components described in the first embodiment described above.
Accordingly, other exemplary embodiments are described below.
In the first embodiment, the water has been described as an example of the heating medium. The heating medium may be any liquid that can transport heat by the flow of the heating medium. Therefore, the heating medium is not limited to the water.
In the first embodiment, the plate water-refrigerant heat exchanger 30 has been described as an example of the utilization-side heat exchanger, but is merely an example. The utilization-side heat exchanger may be a heat exchanger that can exchange heat between the refrigerant and the heating medium, but is not limited to the plate heat exchanger. For example, the utilization-side heat exchanger may be a shell-and-tube heat exchanger.
The above-described embodiment is provided to exemplify the technique according to the present disclosure, and thus various modifications, replacements, additions, omissions, and the like can be made within the scope of the claims or their equivalents.

(Supplementary Note)

The following techniques are disclosed based on the above description of the embodiment.
(Technique 1) A heat pump apparatus including: a refrigerant circuit including a utilization-side heat exchanger, which exchanges heat between a refrigerant and a heating medium, inside a housing; and a heating medium pipe through which the heating medium flowing out from the utilization-side heat exchanger flows, in which: a flow meter is provided inside the housing to be connected to an outlet of the heating medium pipe and to measure a flow rate of the heating medium; and the heating medium pipe is formed with an outlet-side straight portion that extends in a straight line to the flow meter.
Thus, it is possible to easily reduce the turbulence in the flow of the heating medium that reaches the flow meter. For this reason, it is possible to easily prevent the erroneous measurement of the flow rate of the heating medium.
(Technique 2) In the heat pump apparatus according to Technique 1, a gas-liquid separator is provided to remove gas from the heating medium flowing out from the utilization-side heat exchanger, and the heating medium pipe is connected to a liquid-side outlet of the gas-liquid separator.
Thus, even when the heating medium contains gas, it is possible to easily remove the gas from the heating medium before the heating medium reaches the flow meter. For this reason, it is possible to easily prevent the erroneous measurement of the flow rate of the heating medium.
(Technique 3) In the heat pump apparatus according to Technique 1 or 2, the outlet-side straight portion extends horizontally, an outlet-side connection valve is provided on an outlet side of the flow meter to protrude outward from the housing, and the outlet-side straight portion, the flow meter, and the outlet-side connection valve are aligned in a straight line.
Thus, the heating medium flowing through the outlet-side straight portion of the heating medium pipe can reach the outlet-side connection valve outside the housing without bending of the flow channel. For this reason, it is possible to easily reduce resistance to the flow of the heating medium.
(Technique 4) In the heat pump apparatus according to any one of Techniques 1 to 3, the outlet-side straight portion is located below an outlet for heating medium in the utilization-side heat exchanger.
Thus, it is possible to easily reduce the pressure loss of the heating medium due to the difference in height between the outlet of the heating medium in the utilization-side heat exchanger and the outlet-side straight portion. For this reason, it is possible to easily reduce energy required to make the heating medium flow.
(Technique 5) In the heat pump apparatus according to any one of Techniques 1 to 4, the utilization-side heat exchanger is provided forward of a center in a front-rear direction inside the housing, the liquid-side outlet of the gas-liquid separator is located rearward of the utilization-side heat exchanger, the outlet-side straight portion extends in the front-rear direction from a position forward of a rear end of the utilization-side heat exchanger to a position rearward of the center in the front-rear direction inside the housing, and the flow meter is located rearward of the outlet-side straight portion.
Thus, it is possible to make the outlet-side straight portion as long as possible in the front-rear direction, and to easily reduce the turbulence in the flow of the heating medium that reaches the flow meter. For this reason, it is possible to easily prevent the erroneous measurement of the flow rate of the heating medium.

Industrial Applicability

The present disclosure is applicable to a heat pump apparatus configured to exchange heat between a refrigerant and a heating medium as a liquid and including a pipe through which the heating medium flows. Specifically, the present disclosure is applicable to an apparatus having a heat exchanger, such as an outdoor unit of a heat pump hot water heater, configured to exchange heat between a heating medium as water and a refrigerant.

Reference Signs List

1 hot water heater
10 outdoor unit
11 housing
11a bottom plate
11b front panel
12 compressor
13 flow channel switching mechanism
14 air heat exchanger
15 outdoor air-blowing fan
16 expansion valve
17 air-blowing fan room
18 machine room
19 partition plate
21 circulation pump
22 inlet-side connection valve
23 gas-liquid separator
24 liquid-side outlet
25 flow meter
26 measuring tube
27 outlet-side connection valve
30 plate water-refrigerant heat exchanger
30a rear end
31 first refrigerant-side connection port
32 second refrigerant-side connection port
34 first water-side connection port
35 second water-side connection port (heating medium outlet of utilization-side heat exchanger)
40 water pipe
41 inlet portion
43 inlet-side straight portion
45 curved portion
47 outlet-side straight portion
49 outlet
70 indoor unit
71 indoor heat exchanger
73 indoor air-blowing fan
75 connecting pipe
77 connecting pipe
R refrigerant circuit
W water circuit

Claims

A heat pump apparatus comprising:
a refrigerant circuit (R) including a utilization-side heat exchanger (30), which exchanges heat between a refrigerant and a heating medium, inside a housing; and

a heating medium pipe (40) through which the heating medium flowing out from the utilization-side heat exchanger flows, characterized in that

a flow meter (25) is provided inside the housing to be connected to an outlet of the heating medium pipe and to measure a flow rate of the heating medium, and

the heating medium pipe is formed with an outlet-side straight portion (47) that extends in a straight line to the flow meter.
The heat pump apparatus according to claim 1, wherein
a gas-liquid separator (23) is provided to remove gas from the heating medium flowing out from the utilization-side heat exchanger, and

the heating medium pipe is connected to a liquid-side outlet (24) of the gas-liquid separator.
The heat pump apparatus according to claim 1, wherein
the outlet-side straight portion extends horizontally,

an outlet-side connection valve (27) is provided on an outlet side of the flow meter to protrude outward from the housing, and

the outlet-side straight portion, the flow meter, and the outlet-side connection valve are aligned in a straight line.
The heat pump apparatus according to claim 1, wherein
the outlet-side straight portion is located below an outlet for the heating medium in the utilization-side heat exchanger.
The heat pump apparatus according to claim 2, wherein
the utilization-side heat exchanger is provided forward of a center (C) in a front-rear direction inside the housing,

the liquid-side outlet of the gas-liquid separator is located rearward of the utilization-side heat exchanger,

the outlet-side straight portion extends in the front-rear direction from a position forward of a rear end of the utilization-side heat exchanger to a position rearward of the center in the front-rear direction inside the housing, and

the flow meter is located rearward of the outlet-side straight portion.