Heat pump device

Abstract

To provide a heat pump device that has a simple structure, and can restrain a rapid outflow of a leaked refrigerant to an indoor space when a refrigerant leak from a heat exchanger, etc. occurs.SOLUTION: A heat pump device comprises: an outdoor heat exchanger 14; a water heat exchanger 32; a refrigerant pipe 11 connecting the outdoor heat exchanger 14 and the water heat exchanger 32, and filled with a refrigerant; a water pipe 35 connected to the water heat exchanger 32, and filled with water; and a relay case 38 forming an outer frame of a relay 30 arranged in an indoor space 3 of a building 1, and internally housing the water heat exchanger 32. In the relay case 38, a through hole 39 is formed at a position equal to or higher than a preset reference height from a bottom surface of the relay case 38. The relay case 38 can prevent gas in the relay case 38 from leaking out to the indoor space 3 in at least a range below the reference height from the bottom surface. The refrigerant pipe 11 and the water pipe 35 are passed into the through hole 39.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] In a heat pump device, a refrigerant circuit for circulating a refrigerant, a heat medium circuit for flowing a heat medium, a heat exchanger for performing heat exchange between the refrigerant and the heat medium, and at least an indoor unit for housing the heat exchanger are provided. The indoor unit has a container for housing the heat exchanger, and it is known that a first opening communicating with the outdoors is formed in the container without passing through the indoor space (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a heat pump device as shown in Patent Document 1, it is necessary to separately provide a sealed container for housing the heat exchanger in the housing of the indoor unit that houses the heat exchanger for performing heat exchange between the refrigerant and the heat medium.

[0005] The present disclosure has been made to solve such problems. The object is to provide a heat pump device having a refrigerant circuit in which a refrigerant circulates and a heat medium circuit in which a heat medium circulates, and in which a heat exchanger for performing heat exchange between the refrigerant and the heat medium is disposed indoors in a building, and which can suppress a rapid outflow of leaked refrigerant into the indoor space when refrigerant leakage occurs from the heat exchanger or the like with a simple configuration.

Means for Solving the Problems

[0006] The heat pump device according to the present disclosure includes a first heat exchanger that exchanges heat between a refrigerant and air, a second heat exchanger that exchanges heat between the refrigerant and water, a refrigerant pipe that connects the first heat exchanger and the second heat exchanger and in which the refrigerant is enclosed, a water pipe that is connected to the second heat exchanger and in which water is enclosed, a relay machine housing that forms an outer shell of a relay machine disposed indoors in a building and houses the second heat exchanger therein. A through hole is formed in the relay machine housing at a position higher than a preset reference height from the bottom surface of the relay machine housing. The relay machine housing can prevent leakage of gas in the relay machine housing into the indoor space at least in a range less than the reference height from the bottom surface. The refrigerant pipe and the water pipe are passed through the through hole.

Effect of the Invention

[0007] According to the heat pump device of the present disclosure, in a heat pump device in which a heat exchanger that exchanges heat between a refrigerant and a heat medium is disposed indoors in a building, it has the effect of being able to suppress a rapid outflow of leaked refrigerant into the indoor space with a simple configuration when refrigerant leakage occurs from the heat exchanger or the like.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0009] A mode for implementing a heat pump device according to the present disclosure will be described with reference to the accompanying drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and overlapping descriptions will be appropriately simplified or omitted. In the following description, for convenience, the positional relationship of each structure may be expressed based on the illustrated state. Note that the present disclosure is not limited to the following embodiments, and within the scope not departing from the gist of the present disclosure, any combination of the embodiments, modification of any component of each embodiment, or omission of any component of each embodiment is possible.

[0010] Embodiment 1. Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 6. FIG. 1 is a diagram showing the overall configuration of the heat pump device. FIG. 2 is a diagram schematically showing the configuration of the relay machine included in the heat pump device. FIG. 3 is a block diagram showing the configuration of the control system of the heat pump device. FIG. 4 is a diagram schematically showing another example of the configuration of the relay machine included in the heat pump device. FIG. 5 is a diagram schematically showing the configuration of a modified example of the heat pump device. FIG. 6 is a diagram showing an example of the configuration for realizing the functions of the control device of the heat pump device.

[0011] The heat pump device according to this disclosure can be applied to, for example, air conditioners including room air conditioners and commercial package air conditioners, water heaters, showcases, refrigerators, chiller systems, etc., and can be used for a heat pump device provided with a primary circuit (refrigerant circuit) in which a refrigerant circulates and a secondary circuit (heat medium circuit) in which a liquid heat medium (for example, water) circulates.

[0012] Fig. 1 shows a configuration example when the heat pump device according to this embodiment is applied to an air conditioner. In the example shown in the figure, the heat pump device includes an outdoor unit 10, an indoor unit 20, and a relay unit 30. The outdoor unit 10 is installed outdoors 2 of a building 1 (not shown in Fig. 1). The indoor unit 20 and the relay unit 30 are installed indoors 3 of the building 1. The relay unit 30 is for performing heat exchange between a refrigerant and a heat medium such as water. The water heated or cooled by heat exchange with the refrigerant is distributed from the relay unit 30 to the load at the usage destination. The indoor unit 20 is an example of such a load. The indoor unit 20 is installed indoors in a room to be air-conditioned in the indoor area 3. The relay unit 30 is installed indoors in a room that is not the object of air conditioning in the indoor area 3. For example, the relay unit 30 is installed in indoor spaces such as a kitchen, a bathroom, a storage space (such as a closet), and a laundry room in the indoor area 3.

[0013] The outdoor unit 10 and the relay unit 30 are connected by a refrigerant pipe 11. The outdoor unit 10 includes an outdoor heat exchanger 14. The relay unit 30 includes a water heat exchanger 32. The refrigerant pipe 11 is provided in a circulating manner between the outdoor heat exchanger 14 of the outdoor unit 10 and the water heat exchanger 32 of the relay unit 30. A refrigerant is enclosed in the refrigerant pipe 11. From the viewpoint of global environmental protection, it is desirable to use a refrigerant with a small global warming potential (GWP) enclosed in the refrigerant pipe 11. This refrigerant is heavier than air. That is, this refrigerant has a larger average molecular weight (higher density) than air and has the property of sinking downward in the gravitational direction (vertical direction) in the air.

[0014] As such a refrigerant, specifically, for example, one or more refrigerants selected from tetrafluoropropene (CF3CF=CH2: HFO-1234yf), difluoromethane (CH2F2: R32), propane (R290), propylene (R1270), ethane (R170), butane (R600), isobutane (R600a), 1,3,3,3-tetrafluoro-1-propene (CF3-CH=CHF: HFO-1234ze), etc. can be used. Specific examples of the mixed refrigerant include R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, R459A, R474A, R479A, etc. These refrigerants include those having flammability (slightly flammable or highly flammable).

[0015] In addition to the outdoor heat exchanger 14 described above, the outdoor unit 10 further includes a compressor 12, a four-way valve 13, an outdoor fan 15, and an expansion valve 16. The refrigerant pipe 11 annularly connects the compressor 12, the outdoor heat exchanger 14, the expansion valve 16, and the water heat exchanger 32. Thereby, a refrigerant circuit in which the refrigerant circulates between the outdoor heat exchanger 14 and the water heat exchanger 32 is formed.

[0016] The compressor 12 is a device that compresses the supplied refrigerant to increase the pressure and temperature of the refrigerant. The compressor 12 can use, for example, a rotary compressor or a scroll compressor, etc.

[0017] The expansion valve 16 expands the flowing-in refrigerant and reduces the pressure of the refrigerant. That is, the expansion valve 16 is a pressure-reducing device that reduces the pressure of the refrigerant. In the configuration example described here, the expansion valve 16 is a linear electric expansion valve (LEV). Therefore, by closing the expansion valve 16, the flow of the refrigerant can be blocked.

[0018] The outdoor heat exchanger 14 is a heat source side air heat exchanger that exchanges heat between the refrigerant flowing into the outdoor heat exchanger 14 and the air. The outdoor fan 15 generates an air current in the air duct inside the outdoor unit housing described later, and blows air so that the outside air passes around the outdoor heat exchanger 14. The outdoor heat exchanger 14 evaporates or condenses the flowing-in refrigerant, thereby exchanging heat with the air of the outdoors 2 sent from the outdoor fan 15, and cools or heats the air.

[0019] The four-way valve 13 is a valve that switches the connection destination on the discharge side of the compressor 12 between the outdoor heat exchanger 14 and the water heat exchanger 32. The four-way valve 13 is a valve that switches the connection destination on the discharge side of the compressor 12 between the outdoor heat exchanger 14 and the water heat exchanger 32. By switching the four-way valve 13, the circulation direction of the refrigerant in the refrigerant circuit can be reversed.

[0020] The relay unit 30 and the indoor unit 20 are connected by a water pipe 35. The indoor unit 20 includes an indoor heat exchanger 21. The water pipe 35 is provided circularly between the water heat exchanger 32 of the relay unit 30 and the indoor heat exchanger 21 of the indoor unit 20. Water, which is a liquid heat medium, is enclosed in the water pipe 35. That is, the water pipe 35 is a heat medium pipe filled with water, which is a liquid heat medium, inside. Note that water is an example of a liquid heat medium. As the liquid heat medium, brine or the like can also be used.

[0021] The water heat exchanger 32 is a liquid heat exchanger that exchanges heat between the refrigerant flowing into the water heat exchanger 32 and water (liquid heat medium). For the water heat exchanger 32, for example, a plate heat exchanger or a double pipe heat exchanger having high heat exchange efficiency is used.

[0022] The indoor heat exchanger 21 is a utilization-side heat exchanger that exchanges heat between the water (liquid heat medium) flowing into the indoor heat exchanger 21 and the object to be heated or cooled using heat. The object to be heated or cooled using heat varies depending on whether the heat pump device is applied to an air conditioner, a water heater, a showcase, a refrigerator, or the like. For example, when the heat pump device is applied to an air conditioner, a showcase, or a refrigerator, the object to be heated or cooled using heat is air. Also, when the heat pump device is applied to a water heater, the object to be heated or cooled using heat is water. The indoor heat exchanger 21 heats or cools the target air or water by exchanging heat between the flowing high-temperature or low-temperature water and the target air or water.

[0023] As described above, here, a configuration example in which the heat pump device is applied to an air conditioner will be described. The indoor unit 20 further includes an indoor fan 22 in addition to the indoor heat exchanger 21 described above. The indoor fan 22 generates an air current in the air passage in the indoor unit housing described later and blows air so that the indoor air passes around the indoor heat exchanger 21. The indoor heat exchanger 21 heats or cools the indoor air by exchanging heat between the flowing high-temperature or low-temperature water and the indoor air sent from the indoor fan 22.

[0024] The outdoor heat exchanger 14 in this embodiment is an example of a first heat exchanger that exchanges heat between a refrigerant and air. The water heat exchanger 32 in this embodiment is an example of a second heat exchanger that exchanges heat between a refrigerant and water. The indoor heat exchanger 21 in this embodiment is an example of a third heat exchanger that exchanges heat between water and air. The outdoor heat exchanger 14, which is the first heat exchanger, is arranged outdoors 2 of the building 1. The water heat exchanger 32, which is the second heat exchanger, and the indoor heat exchanger 21, which is the third heat exchanger, are arranged indoors 3 of the building 1. And the refrigerant pipe 11 annularly connects the outdoor heat exchanger 14, which is the first heat exchanger, and the water heat exchanger 32, which is the second heat exchanger.

[0025] In addition, the water pipe 35 annularly connects the water heat exchanger 32, which is the second heat exchanger, and the indoor heat exchanger 21, which is the third heat exchanger. That is, the water pipe 35 has an outgoing water pipe and a return water pipe. The outgoing water pipe is a pipe through which water flows from the water heat exchanger 32 toward the indoor heat exchanger 21. The return water pipe is a pipe through which water flows from the indoor heat exchanger 21 toward the water heat exchanger 32.

[0026] In addition to the water heat exchanger 32 described above, the relay unit 30 further includes a pump 31. The pump 31 is for causing water, which is a liquid heat medium, to flow through the water heat exchanger 32 and the indoor heat exchanger 21. The pump 31 is provided in the return water pipe of the water pipe 35. The water pipe 35 annularly connects the water heat exchanger 32, the indoor heat exchanger 21, and the pump 31. Therefore, a water circuit in which water is circulated between the water heat exchanger 32 and the indoor heat exchanger 21 by the pump 31 is formed.

[0027] The pump 31 causes water (liquid heat medium) to flow in a predetermined circulation direction in the water pipe 35 (heat medium pipe) formed annularly in this way. This circulation direction is the direction in which water, which is a liquid heat medium, passes through the pump 31, the water heat exchanger 32, which is a liquid heat exchanger, and the indoor heat exchanger 21 in this order.

[0028] A pressure valve 33 is provided in the outgoing water pipe of the water pipe 35. The pressure valve 33 is a control valve capable of opening the water pipe 35 and keeping the internal pressure of the water pipe 35 constant when the internal pressure of the water pipe 35 becomes equal to or higher than a preset value. For example, a spring-type pressure valve is used for the pressure valve 33. The spring-type pressure valve is normally closed by pressing the valve body against the valve seat by the elastic force of the spring. When the pressure in the pipe reaches the set value, the pressure acting on the valve body from the inside pushes the valve body upward against the elastic force of the spring, and the valve opens.

[0029] An air vent valve 34 is further provided in the supply water pipe of the water pipe 35. The air vent valve 34 is a valve capable of discharging gas such as air in the water pipe 35 to the outside. As the air vent valve 34, for example, a float-type automatic air vent valve is used. The float-type automatic air vent valve has a sealing function to prevent the backflow of air by the float and can discharge only the gas in the water. More specifically, normally, the inside of the air vent valve 34 is filled with water and is sealed by the close contact between the opening and the float. When air accumulates inside the air vent valve 34, the water level inside the air vent valve 34 drops. Along with this, the float descends and a gap is formed between the opening and the float, and only the gas is discharged to the outside.

[0030] If air exists in the water pipe 35 or the like of the water circuit, the smooth flow of water is hindered. Also, if air enters the pump 31, there is a possibility that it will rotate idly (so-called "air biting") and it will be impossible to circulate water. For example, when installing a heat pump device, gas such as air may be mixed into the water circuit. Also, during the trial operation of the heat pump device or the like, gas such as air may be separated from the water in the water circuit. When gas has entered the water circuit in this way, the gas circulates in the water circuit together with the water that is the heat medium. When the gas circulating in the water circuit passes through the air vent valve 34 provided in the supply water pipe, it is discharged from the air vent valve 34 to the outside of the water circuit. Thereby, it is possible to prevent air from entering the pump 31 and prevent the pump 31 from rotating idly.

[0031] The outdoor unit 10 includes an outdoor unit housing. Inside the outdoor unit housing, a compressor 12, a four-way valve 13, an outdoor heat exchanger 14, an outdoor fan 15, an expansion valve 16, and a part of the refrigerant pipe 11 are accommodated. Also, the indoor unit 20 includes an indoor unit housing. Inside the indoor unit housing, an indoor heat exchanger 21, an indoor fan 22, and a part of the water pipe 35 are accommodated. And, as shown in FIG. 2, the relay unit 30 includes a relay unit housing 38. The relay unit housing 38 is a member that forms the outer shell of the relay unit 30. Inside the relay unit housing 38, a pump 31, a water heat exchanger 32, a pressure valve 33, an air vent valve 34, a part of the refrigerant pipe 11, and a part of the water pipe 35 are accommodated.

[0032] The outdoor unit housing is formed with a suction port and a blowout port that communicate the inside and the outside of the outdoor unit housing. Inside the outdoor unit housing, an air passage is formed that leads from the suction port, passes through the outdoor heat exchanger 14 and the outdoor fan 15, and communicates with the blowout port. This air passage is for exchanging heat of the air taken in from the outside of the outdoor unit housing with the outdoor heat exchanger 14 and then discharging it to the outside of the outdoor unit housing.

[0033] Similarly, the indoor unit housing is also formed with a suction port and a blowout port that communicate the inside and the outside of the indoor unit housing. Inside the indoor unit housing, an air passage is formed that leads from the suction port, passes through the indoor heat exchanger 21 and the indoor fan 22, and communicates with the blowout port. This air passage is for exchanging heat of the air taken in from the outside of the indoor unit housing with the indoor heat exchanger 21 and then discharging it to the outside of the indoor unit housing.

[0034] The refrigerant circuit and the water circuit configured in this way perform heat exchange between the refrigerant and air in the outdoor heat exchanger 14, perform heat exchange between the refrigerant and water in the water heat exchanger 32, and further perform heat exchange between the water and air in the indoor heat exchanger 21, thereby acting as a heat pump that transfers heat between the outdoor unit 10 on the heat source side and the indoor heat exchanger 21 on the utilization side. That is, it is an indirect-type heat pump device using a primary circuit (refrigerant circuit) in which a combustible refrigerant circulates and a secondary circuit in which a non-combustible heat medium (here, water) circulates.

[0035] By switching the four-way valve 13, the circulation direction of the refrigerant in the refrigerant circuit can be reversed to switch between the cooling operation and the heating operation. In the case of the cooling operation, the connection destination on the discharge side of the compressor 12 is set to the outdoor heat exchanger 14 by the four-way valve 13. In the present disclosure, setting the connection destination on the discharge side of the compressor 12 to the outdoor heat exchanger 14 by the four-way valve 13 is also referred to as setting the four-way valve 13 to the "cooling orientation". On the other hand, in the case of the heating operation, the connection destination on the discharge side of the compressor 12 is set to the water heat exchanger 32 by the four-way valve 13. In the present disclosure, setting the connection destination on the discharge side of the compressor 12 to the water heat exchanger 32 by the four-way valve 13 is also referred to as setting the four-way valve 13 to the "heating orientation".

[0036] During the cooling operation, in the primary refrigerant circuit, the refrigerant becomes high-temperature and high-pressure by the compressor 12, and flows into the outdoor heat exchanger 14 through the four-way valve 13. At this time, the outdoor heat exchanger 14 functions as a condenser and condenses the flowing-in refrigerant. That is, the high-temperature refrigerant flowing into the outdoor heat exchanger 14 exchanges heat with the low-temperature outside air and condenses into liquid refrigerant.

[0037] The liquid refrigerant expands through the expansion valve 16 and becomes a refrigerant in a gas-liquid two-phase state in which the gas phase and the liquid phase are mixed at low temperature and low pressure. This low-temperature gas-liquid two-phase refrigerant flows into the water heat exchanger 32, exchanges heat with the water circulating in the water circuit, evaporates, and becomes gas refrigerant. By this heat exchange, the water in the water circuit is cooled. That is, the water heat exchanger 32 acts as a heat absorber that absorbs heat from the water in the water circuit and cools the water. The gas refrigerant passes through the four-way valve 13 and flows into the compressor 12 again to become high-temperature and high-pressure refrigerant.

[0038] In the water circuit, water is circulated by the pressure generated by the pump. The water cooled to a low temperature in the water heat exchanger 32 flows through the water pipe 35 while remaining at a low temperature and flows into the indoor heat exchanger 21. The water flowing into the indoor heat exchanger 21 exchanges heat with the indoor air and is heated. At this time, the indoor air is cooled. The heated water advances to the water pipe 35, passes through the pump 31, and flows into the water heat exchanger 32 again to be cooled into low-temperature water.

[0039] During the heating operation, in the primary refrigerant circuit, the refrigerant becomes high-temperature and high-pressure by the compressor 12, and flows into the water heat exchanger 32 through the four-way valve 13. The refrigerant flowing into the water heat exchanger 32 exchanges heat with the water circulating in the water circuit and condenses into liquid refrigerant. At this time, the water circulating in the water circuit is heated. That is, the water heat exchanger 32 functions as a radiator and heats the water flowing through the water circuit.

[0040] The liquid refrigerant expands through the expansion valve 16 to become a low-temperature and low-pressure gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant flows into the outdoor heat exchanger 14. At this time, the outdoor heat exchanger 14 functions as an evaporator and evaporates the flowing-in refrigerant. That is, the gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 14 exchanges heat with the outside air and evaporates to become a gas refrigerant. The gas refrigerant flows through the four-way valve 13 and flows into the compressor 12 again to become a high-temperature and high-pressure refrigerant.

[0041] In the water circuit, the water in the water circuit is circulated by the pressure generated by the pump 31. First, the high-temperature water heated by the water heat exchanger 32 flows through the water pipe 35 while remaining at a high temperature and flows into the indoor heat exchanger 21. The water flowing into the indoor heat exchanger 21 exchanges heat with the indoor air and is cooled. At this time, the indoor air is heated. The cooled water advances to the water pipe 35, passes through the pump 31, and flows into the water heat exchanger 32 again to be heated and become high-temperature water.

[0042] In the heat pump device according to this embodiment, as shown in FIG. 2, inside the relay machine housing 38, the water heat exchanger 32, which is a second heat exchanger, is accommodated. A through hole 39 is formed in the relay machine housing 38. The through hole 39 is arranged at a position in the relay machine housing 38 that is at a reference height H or more from the bottom surface of the relay machine housing 38. And the refrigerant pipe 11 and the water pipe 35 are passed through the through hole 39. The number of through holes 39 formed in the relay machine housing 38 is not limited to one. A plurality of through holes 39 may be formed in the relay machine housing 38. In this case, all of the plurality of through holes 39 are arranged at positions in the relay machine housing 38 that are at a reference height H or more from the bottom surface.

[0043] The relay housing 38 can prevent the gas inside the relay housing 38 from leaking to the outside of the relay housing 38, that is, into the space of Room 3, at least in the range below the reference height H from the bottom surface. The portion of the relay housing 38 other than the through-hole 39 is configured to be airtight. The relay housing 38 is generally composed of a combination of a plurality of sheet metals processed by sheet metal working. In such a case, the joints between the respective steel plates are hermetically sealed by a sealing member such as a silicon resin or a caulking material. As the sealing member, for example, a material having a low thermal conductivity, such as urethane, foam material, or rubber, in other words, a material having high heat insulation properties, may be used. By doing so, the heat insulation performance of the relay housing 38 can be improved and the temperature inside the relay housing 38 can be stabilized.

[0044] Note that an opening may be formed on the side surface of the relay housing 38, and a door that can open and close this opening may be provided. When this opening and the door are arranged below the reference height H, a sealing member may be provided on one or both of the peripheral edge of the door and the peripheral edge of the opening so that the opening is hermetically sealed when the door is closed. By providing such an opening and a door, the maintainability can be improved.

[0045] In the heat pump device configured as described above, a low-temperature refrigerant flows into the water heat exchanger 32 during a cooling operation or the like. At this time, a refrigerant below 0°C (the freezing point of water) may flow into the water heat exchanger 32, the water circulating in the water circuit may freeze, and the water heat exchanger 32 may be damaged due to the volume expansion of the water caused by the freezing. Also, for example, the water heat exchanger 32 may be damaged due to aging deterioration, external stress, or the like.

[0046] As described above, the water heat exchanger 32 is housed inside the relay housing 38. When the refrigerant leaks from the water heat exchanger 32 due to damage to the water heat exchanger 32, the leaked refrigerant flows out into the relay housing 38. And since the relay housing 38 can prevent the gas inside the relay housing 38 from leaking to the outside of the relay housing 38 at least in the range below the reference height H from the bottom surface, the refrigerant that has flowed into the relay housing 38 is stored inside the relay housing 38 within a volume range that is at least below the reference height H from the bottom surface.

[0047] Also, even when refrigerant leaks from the connection portion between the hydrothermal exchanger 32 and the refrigerant pipe 11 or from the portion of the refrigerant pipe 11 within the relay housing 38, the leaked refrigerant flows out into the relay housing 38. As described above, a refrigerant heavier than air is used. For this reason, the leaked refrigerant accumulates within the relay housing 38 and is stored within the relay housing 38 within a volume range that is at least at or below the reference height H from the bottom surface. In this way, in the heat pump apparatus according to this embodiment, without separately providing a sealed container or the like that hermetically houses the hydrothermal exchanger 32, when refrigerant leakage occurs in the hydrothermal exchanger 32 and the refrigerant pipe 11 provided in the relay 30 in the indoor space 3, the leaked refrigerant is temporarily stored in the relay housing 38, and it is possible to suppress the refrigerant from rapidly flowing out directly from the leakage point to the outside of the relay housing 38, that is, into the space of the indoor space 3. For this reason, with a simple configuration, when refrigerant leakage occurs from the hydrothermal exchanger 32 or the like, it is possible to suppress the rapid inflow of the leaked refrigerant into the space of the indoor space 3. Therefore, it is possible to suppress the formation of a region with a high refrigerant concentration in the indoor space 3 in a short period of time.

[0048] Also, when the amount of leaked refrigerant exceeds the volume of the range below the reference height H of the relay housing 38 and refrigerant leaks from within the relay housing 38, the refrigerant flows out into the space of the indoor space 3 through the through-hole 39 located at a position of the reference height H or higher. Therefore, the refrigerant diffuses while settling from a relatively high position of the reference height H or higher. For this reason, even if the refrigerant leaks from the relay housing 38 into the space of the indoor space 3, it is possible to promote the diffusion of the refrigerant and suppress the formation of a region with a high refrigerant concentration in the indoor space 3.

[0049] The reference height H, that is, the minimum distance from the bottom surface to the through hole 39, may be set to a dimension such that at least half of the amount of refrigerant filled in the refrigerant circuit can be stored in the range below the reference height H of the relay housing 38. Hereinafter, a specific example will be given for explanation. Assume that the refrigerant is R290, the refrigerant filling amount of the refrigerant circuit is 1 [kg], and the inner dimensions of the bottom surface of the relay housing 38 are 0.595 [m] in width and 0.68 [m] in depth. The bottom area of the relay housing 38 is 0.595 × 0.68 = 0.405 [m^2].

[0050] When 1 kg of R290 becomes all gas under the conditions of 1 atmospheric pressure and 25 °C, its volume becomes approximately 554 [L], that is, 0.554 [m^3]. Assuming that all 0.554 [m^3] of R290 is stored in the relay housing 38 with a bottom area of 0.405 [m^2], its height becomes 0.554 / 0.405 = 1.37 [m]. Therefore, the reference height H required to store at least half of the amount of refrigerant filled in the refrigerant circuit is 1.37 / 2 = 0.68 [m].

[0051] As shown in FIG. 2, the pressure valve 33 and the air vent valve 34 may be further accommodated in the relay housing 38. When the water heat exchanger 32 is damaged, the refrigerant flow path and the water flow path in the water heat exchanger 32 may communicate with each other. In this case, if the internal pressure of the refrigerant pipe 11 is higher than the internal pressure of the water pipe 35, the refrigerant in the refrigerant pipe 11 of the refrigerant circuit may invade into the water pipe 35 of the water circuit. The refrigerant flowing into the water heat exchanger 32 is high-pressure refrigerant compressed by the compressor 12. Therefore, when the water heat exchanger 32 is damaged and the refrigerant flow path and the water flow path in the water heat exchanger 32 communicate with each other, the refrigerant invades into the water pipe 35 of the water circuit, and the invaded refrigerant becomes gas and flows in the water circuit. Then, the gaseous refrigerant that has invaded into the water pipe 35 is discharged to the outside of the water pipe 35 from one or both of the pressure valve 33 and the air vent valve 34.

[0052] By accommodating the pressure valve 33 and the air bleeding valve 34 within the relay machine housing 38, in such a case, the refrigerant discharged from the pressure valve 33 or the air bleeding valve 34 can be temporarily stored within the relay machine housing 38, suppressing the rapid outflow of the refrigerant directly from the valve to the outside of the relay machine housing 38, that is, into the space of Room 3 indoors. For this reason, without separately providing a sealed container or the like, with a simple configuration, when refrigerant leakage occurs from the water heat exchanger 32 or the like, the rapid inflow of the leaked refrigerant into the space of Room 3 can be suppressed. Therefore, it is possible to suppress the formation of a region with a high refrigerant concentration in Room 3 within a short period of time.

[0053] As shown in FIGS. 1 and 2, the heat pump device according to this embodiment may further include a stirring fan 37. As shown in FIG. 2, the stirring fan 37 is provided within the relay machine housing 38. The stirring fan 37 generates an air flow within the relay machine housing 38 and stirs the air within the relay machine housing 38. By providing such a stirring fan 37, the air within the relay machine housing 38 is stirred, ventilation within the relay machine housing 38 through the through holes 39 is promoted, and local temperature rise and condensation within the relay machine housing 38 can be suppressed.

[0054] The stirring fan 37 may blow air constantly. Here, the term "constantly" means always as long as power for operation is supplied to the stirring fan 37. That is, if the heat pump device is connected to, for example, a commercial power supply, the stirring fan 37 operates regardless of the operating state of the heat pump device itself. Also, an emergency battery, an uninterruptible power supply device, etc. for operating the stirring fan 37 may be provided. By doing so, even when the heat pump device is stopped, the stirring fan 37 can be constantly operated to stir the air within the relay machine housing 38. Note that instead of constantly operating the stirring fan 37, for example, a temperature sensor may be installed within the relay machine housing 38, and the stirring fan 37 may be operated when the detected value of the temperature sensor becomes equal to or higher than a preset reference temperature.

[0055] As shown in FIGS. 1 and 2, the heat pump apparatus according to this embodiment may further include a refrigerant sensor 36. The refrigerant sensor 36 is a sensor that detects the refrigerant inside the relay housing 38. As shown in FIG. 2, the refrigerant sensor 36 is installed inside the relay housing 38. The refrigerant sensor 36 can detect at least the same kind of refrigerant as that enclosed in the refrigerant pipe 11. The refrigerant sensor 36 can use sensors of various types such as, for example, a catalytic combustion type, a semiconductor type, a heat conduction type, a low potential electrolysis type, and an infrared type. The refrigerant sensor 36 converts the refrigerant concentration inside the relay housing 38 into an electrical signal and outputs it.

[0056] Also, an oxygen sensor can be used as the refrigerant sensor 36. When an oxygen sensor is used, the oxygen concentration is obtained based on the sensor output, and the concentration of the inflowing gas, that is, the refrigerant, can be indirectly detected by calculating the concentration of the inflowing gas inversely assuming that the decrease in the oxygen concentration is due to the inflowing gas. As the oxygen sensor, for example, various types such as a galvanic cell type, a polarographic type, and a zirconia type can be used.

[0057] The configuration of the control system of the heat pump apparatus according to this embodiment is shown in FIG. 3. As shown in the figure, the heat pump apparatus according to this embodiment includes a control device 100. And the control device 100 includes a leakage detection unit 111, a storage unit 112, a notification unit 113, and a control unit 114.

[0058] The leakage detection unit 111 detects the occurrence of refrigerant leakage inside the relay housing 38 based on the detection result of the refrigerant sensor 36. As described above, the refrigerant sensor 36 can detect the refrigerant directly or indirectly. And the refrigerant sensor 36 outputs a detection signal corresponding to the detected refrigerant concentration.

[0059] The detection signal output from the refrigerant sensor 36 is input to the leakage detection unit 111. The leakage detection unit 111 determines whether the refrigerant concentration indicated by the detection signal from the refrigerant sensor 36 is equal to or higher than the refrigerant leakage determination reference value. The refrigerant leakage determination reference value is a preset value. The preset refrigerant leakage determination reference value is stored in the storage unit 112. The leakage detection unit 111 makes a determination by comparing the refrigerant leakage determination reference value acquired from the storage unit 112 with the refrigerant concentration indicated by the detection signal from the refrigerant sensor 36.

[0060] And when the refrigerant concentration indicated by the detection signal from the refrigerant sensor 36 is equal to or higher than the refrigerant leakage determination reference value, the leakage detection unit 111 outputs a refrigerant leakage detection signal to the control unit 114. The refrigerant leakage detection signal is a signal indicating that refrigerant leakage in the relay housing 38 has been detected. When the heat pump device is provided with the refrigerant sensor 36, in this way, the leakage detection unit 111 detects refrigerant leakage inside the relay housing 38. By providing the refrigerant sensor 36 for detecting refrigerant leakage in the relay housing 38 that houses the water heat exchanger 32, when refrigerant leakage occurs from the water heat exchanger 32 and the refrigerant piping 11, the leaked refrigerant is retained inside the relay housing 38, and while suppressing the diffusion of the leaked refrigerant, the occurrence of refrigerant leakage can be detected promptly.

[0061] The control unit 114 controls the operation of the entire heat pump device by controlling the actuators provided in the heat pump device. The control targets of the control unit 114 include the compressor 12, the four-way valve 13, the outdoor fan 15, the expansion valve 16, the indoor fan 22, the pump 31, the agitation fan 37, and the like.

[0062] When a refrigerant leakage detection signal is input from the leakage detection unit 111, if the compressor 12 is in operation, the control unit 114 may stop the compressor 12. By doing so, the subsequent refrigerant leakage amount can be reduced. When a refrigerant leakage detection signal is input from the leakage detection unit 111 and the compressor 12 is stopped, the control unit 114 may further close the expansion valve 16. By doing so, a further reduction in the subsequent refrigerant leakage amount can be achieved.

[0063] When a refrigerant leakage detection signal is output from the leakage detection unit 111, the notification unit 113 notifies the user, operator, etc. to that effect and prompts the implementation of repairs or the like. The heat pump device includes a speaker for notifying by sound or an LED for notifying by light or the like to notify that the occurrence of refrigerant leakage has been detected inside the relay housing 38. The speaker, LED, etc. are provided, for example, on the housing of the indoor unit 20, the remote controller of the heat pump device, or the like. When a refrigerant leakage detection signal is output from the leakage detection unit 111, the notification unit 113 uses the speaker, LED, etc. to notify that the occurrence of refrigerant leakage has been detected.

[0064] As described above, a refrigerant heavier than air is used. Therefore, the refrigerant sensor 36 is preferably arranged vertically below the water heat exchanger 32 inside the relay housing 38. In this case, the refrigerant sensor 36 may be directly below the water heat exchanger 32 or not. It is even better to arrange the refrigerant sensor 36 at a position close to the bottom inside the relay housing 38. More preferably, the refrigerant sensor 36 is arranged vertically below not only the water heat exchanger 32 but also the refrigerant pipes 11, the pressure valve 33, and the air vent valve 34.

[0065] When the heat pump device is provided with the refrigerant sensor 36, the stirring fan 37 may not be operated constantly, but may be operated when no refrigerant leakage is detected. And when refrigerant leakage is detected, the stirring fan 37 may be stopped. In this case, the control unit 114 operates the stirring fan 37 while no refrigerant leakage detection signal is input from the leakage detection unit 111. And when a refrigerant leakage detection signal is input from the leakage detection unit 111, the control unit 114 stops the stirring fan 37. That is, the stirring fan 37 operates when the refrigerant sensor 36 does not detect refrigerant leakage and stops when the refrigerant sensor 36 detects refrigerant leakage.

[0066] By doing so, during normal times when refrigerant leakage is not detected, the stirring fan 37 stirs the air inside the relay cabinet 38, promotes ventilation inside the relay cabinet 38 through the through-hole 39, and can suppress the temperature rise and the occurrence of condensation inside the relay cabinet 38. On the other hand, when refrigerant leakage is detected, by stopping the stirring fan 37, it is possible to suppress the refrigerant inside the relay cabinet 38 from being stirred by the air flow of the stirring fan 37 and leaking out of the relay cabinet 38 through the through-hole 39, so that the leaked refrigerant can be stored inside the relay cabinet 38.

[0067] In the example shown in FIG. 2, the through-hole 39 is arranged on the upper surface portion of the relay cabinet 38. By doing so, the reference height H can be made to substantially coincide with the total height of the relay cabinet 38. That is, almost all of the internal volume of the relay cabinet 38 can be used to store the leaked refrigerant inside the relay cabinet 38.

[0068] However, the through-hole 39 may be arranged at a location other than the upper surface portion of the relay cabinet 38. For example, as shown in FIG. 4, the through-hole 39 may be formed on the side surface portion of the relay cabinet 38. Even in this case, the distance from the bottom surface of the relay cabinet 38 to the through-hole 39 is equal to or greater than the reference height H.

[0069] The relay 30 further includes an electrical component box 50. Inside the electrical component box 50, electrical components for operating the heat pump device, as well as electrical components such as a substrate on which a control circuit and a power supply circuit are mounted, are accommodated. That is, the control device 100 described above is constituted by the electrical components accommodated in the electrical component box 50.

[0070] An electrical wiring 51 is connected to the electrical component box 50. The electrical wiring 51 is connected to the electrical components accommodated in the electrical component box 50. The electrical component box 50 is arranged indoors in the building 1. In the configuration example shown in FIG. 4, the electrical component box 50 is accommodated inside the relay cabinet 38. And the electrical wiring 51 is passed through the through-hole 39.

[0071] As shown in FIGS. 2 and 4, the upper end of the hydrothermal exchanger 32 may be disposed below the reference height H. By doing so, when refrigerant leakage occurs in the hydrothermal exchanger 32, it is possible to suppress the refrigerant leaked from the hydrothermal exchanger 32 from directly leaking outside the relay housing 38 through the through hole 39. Also, the pressure valve 33 and the air vent valve 34 may be similarly disposed below the reference height H.

[0072] On the other hand, as shown in FIG. 4, the electrical component box 50 may be disposed above the reference height H. As described above, a refrigerant heavier than air is used. For this reason, the leaked refrigerant gradually accumulates from the lower side in the relay housing 38, and when it reaches the through hole 39 at a position equal to or higher than the reference height H from the bottom surface, it leaks out of the relay housing 38 through the through hole 39. By disposing the electrical component box 50 above the reference height H, and further, by disposing the electrical component box 50 above the through hole 39, it is possible to suppress the leaked refrigerant from coming into contact with the electrical components in the electrical component box 50 that serve as an ignition source. In this case, the refrigerant sensor 36 may be disposed between the hydrothermal exchanger 32 and the electrical component box 50.

[0073] Next, a modification of the heat pump apparatus according to this embodiment will be described with reference to FIG. 5. In the description of this modification, redundant descriptions of the same points as the configurations described so far will be omitted, and the description will be centered on the differences, changes, modified points, etc. In this modification, as shown in FIG. 5, a through hole 39 is formed in the upper surface portion of the relay housing 38. And the upper surface portion of the relay housing 38 is disposed in the ceiling space of the building 1. Therefore, the through hole 39 disposed in the upper surface portion of the relay housing 38 is also disposed in the ceiling space of the building 1.

[0074] The reference height H may be set to be equal to or greater than the height from the floor surface to the ceiling surface of the building 1. In the illustrated example, the reference height H is equal to the height from the floor surface to the ceiling surface of the building 1. That is, the relay housing 38 is placed on the floor surface such that the bottom surface of the relay housing 38 contacts the floor surface of the building 1, and the upper surface of the relay housing 38 reaches the ceiling surface of the building 1.

[0075] In this modification example, a duct 40 is provided in the ceiling space of the building 1. One end side of the duct 40 covers at least a part of the through hole 39 of the relay housing 38 and communicates with the internal space of the relay housing 38 through the through hole 39. The other end side of the duct 40 communicates with the outside 2 of the building. The internal space of the duct 40 communicates with the internal space of the relay housing 38 and the outside 2. The duct 40 has airtightness, and the internal space of the duct 40 does not communicate with, for example, the internal space in the ceiling space other than the internal space of the relay housing 38 and the outside 2. In this way, the internal space of the relay housing 38 communicates with the outside 2 through the duct 40.

[0076] The refrigerant pipe 11 is passed through the duct 40. Therefore, even if refrigerant leakage occurs at any location of the refrigerant pipe 11, it is possible to prevent the refrigerant leaked from the refrigerant pipe 11 from leaking into the indoor space 3. Further, an exhaust fan 41 is provided in the duct 40. The exhaust fan 41 is a fan that generates an air flow from the relay housing 38 side toward the outside 2 in the duct 40. By providing such an exhaust fan 41, when refrigerant flows out from the water heat exchanger 32, the refrigerant pipe 11, the pressure valve 33, and the air vent valve 34, the refrigerant can be quickly discharged to the outside 2.

[0077] When the heat pump device includes the refrigerant sensor 36, the exhaust fan 41 may be operated when refrigerant leakage is detected. In this case, the control unit 114 operates the exhaust fan 41 when a refrigerant leakage detection signal is input from the leakage detection unit 111. That is, the exhaust fan 41 operates when the refrigerant sensor 36 detects refrigerant.

[0078] Further, the exhaust fan 41 may be operated constantly. At this time, an emergency battery, an uninterruptible power supply device, etc. for operating the exhaust fan 41 may be provided. By doing so, the inside of the relay housing 38 can be put into a negative pressure state, which promotes the inflow of air into the relay housing 38 from the through hole 39 that does not communicate with the duct 40. And it is possible to promote ventilation and air stirring inside the relay housing 38.

[0079] FIG. 6 is a diagram showing an example of a configuration for realizing the functions of the control device 100 in this embodiment. The functions of the control device 100 are realized, for example, by a processing circuit. The processing circuit may include a processor 101 and a memory 102. The processing circuit may be dedicated hardware 103. A part of the processing circuit may be formed as dedicated hardware 103, and the processing circuit may further include a processor 101 and a memory 102. In the example shown in the figure, a part of the processing circuit is formed as dedicated hardware 103. Also, in the example shown in the figure, the processing circuit further includes a processor 101 and a memory 102.

[0080] Examples of the processing circuit in which a part is at least one piece of dedicated hardware 103 include a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC, an FPGA, or a combination thereof. When the processing circuit includes at least one processor 101 and at least one memory 102, the functions of the control device 100 are realized by software, firmware, or a combination of software and firmware.

[0081] Software and firmware are described as programs and stored in the memory 102. The processor 101 realizes the functions of each part by reading and executing the programs stored in the memory 102. The processor 101 is also referred to as a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, or a DSP. Examples of the memory 102 include non-volatile or volatile semiconductor memories such as RAM, ROM, flash memory, EPROM, and EEPROM, or magnetic disks, flexible disks, optical disks, compact disks, mini disks, and DVDs.

[0082] In this way, the processing circuit of the control device 100 can implement each function of the control device 100 by hardware, software, firmware, or a combination thereof. When the processing circuit of the control device 100 includes at least the processor 101 and the memory 102, the processor 101 executes the program stored in the memory 102 in the control device 100, and the hardware and software of the control device 100 cooperate with each other, whereby the functions of each part included in the control device 100 are realized. Note that the heat pump device is not limited to a configuration in which the operation is controlled by a single control device 100. The operation of the heat pump device may be controlled by cooperation of a plurality of devices.

[0083] Note that in the present disclosure, each embodiment and modification example etc. may be arbitrarily combined without departing from the gist of the present disclosure. Examples of various aspects of the present disclosure are collectively described below as appendices. (Appendix 1) A first heat exchanger that exchanges heat between a refrigerant and air, A second heat exchanger that exchanges heat between the refrigerant and water, A refrigerant pipe that connects the first heat exchanger and the second heat exchanger and in which the refrigerant is enclosed, A water pipe that is connected to the second heat exchanger and in which water is enclosed, A relay machine housing that forms an outer shell of a relay machine disposed indoors in a building and houses the second heat exchanger therein, In the relay machine housing, a through hole is formed at a position equal to or higher than a preset reference height from the bottom surface of the relay machine housing, The relay machine housing can prevent leakage of the gas in the relay machine housing into the room at least in a range from the bottom surface to less than the reference height, The refrigerant pipe and the water pipe are passed through the through hole, a heat pump device. (Appendix 2) A stirring fan provided in the relay machine housing, A sensor provided in the relay machine housing and capable of detecting the refrigerant, The heat pump device according to Supplementary Note 1, wherein the stirring fan operates when the sensor does not detect the refrigerant and stops when the sensor detects the refrigerant. (Supplementary Note 3) The heat pump device according to any one of Supplementary Note 1 or Supplementary Note 2, wherein the upper end of the second heat exchanger is disposed below the reference height. (Supplementary Note 4) The heat pump device according to any one of Supplementary Notes 1 to 3, wherein the through hole is formed in the upper surface portion of the relay machine housing. (Supplementary Note 5) The heat pump device according to any one of Supplementary Notes 1 to 4, wherein the through hole is disposed in the ceiling space of the building. (Supplementary Note 6) The heat pump device according to Supplementary Note 5, wherein the reference height is equal to or greater than the height from the floor surface to the ceiling surface of the building. (Supplementary Note 7) A duct communicating from the through hole to the outside of the building is provided in the ceiling space, The refrigerant pipe is passed through the duct, The heat pump device according to Supplementary Note 5 or Supplementary Note 6, further comprising an exhaust fan provided in the duct. (Supplementary Note 8) The through hole is disposed in the ceiling space of the building, A duct communicating from the through hole to the outside of the building is provided in the ceiling space, The refrigerant pipe is passed through the duct, The heat pump device further comprises an exhaust fan provided in the duct, The heat pump device according to Supplementary Note 2, wherein the exhaust fan operates when the sensor detects the refrigerant. (Supplementary Note 9) The relay machine housing houses electrical components therein, The heat pump device according to any one of Supplementary Notes 1 to 8, wherein the electrical wiring connected to the electrical components is passed through the through hole. (Supplementary Note 10) The heat pump device according to Supplementary Note 9, wherein the electrical components are disposed above the reference height.

Explanation of Reference Numerals

[0084] 1 Building 2 Outdoor 3 Indoor 10 Outdoor Unit 11 Refrigerant Pipe 12 Compressor 13 Four-Way Valve 14 Outdoor Heat Exchanger 15 Outdoor Fan 16 Expansion Valve 20 Indoor Unit 21 Indoor Heat Exchanger 22 Indoor Fan 30 Relay Unit 31 Pump 32 Water Heat Exchanger 33 Pressure Valve 34 Air Bleed Valve 35 Water Pipe 36 Refrigerant Sensor 37 Stirring Fan 38 Relay Unit Housing 39 Through-Hole 40 Duct 41 Exhaust Fan 50 Electrical Component Box 51 Electrical Wiring 100 Control Device 101 Processor 102 Memory 103 Dedicated Hardware 111 Leak Detection Unit 112 Storage Unit 113 Notification Unit 114 Control Unit

Claims

1. a first heat exchanger that exchanges heat between a refrigerant and air; a second heat exchanger that exchanges heat between the refrigerant and water; a refrigerant pipe that connects the first heat exchanger and the second heat exchanger and in which the refrigerant is enclosed; a water pipe that is connected to the second heat exchanger and in which water is enclosed; a relay machine housing that forms an outer shell of a relay machine disposed indoors in a building and houses the second heat exchanger therein; a through hole is formed in the relay machine housing at a position equal to or higher than a preset reference height from the bottom surface of the relay machine housing; the relay machine housing can prevent leakage of the gas in the relay machine housing into the room at least in a range from the bottom surface to less than the reference height; a heat pump device in which the refrigerant pipe and the water pipe are passed through the through hole.

2. a stirring fan provided in the relay machine housing; a sensor provided in the relay machine housing and capable of detecting the refrigerant; The heat pump device according to claim 1, wherein the stirring fan operates when the sensor does not detect the refrigerant and stops when the sensor detects the refrigerant.

3. The heat pump device according to any one of claims 1 or 2, wherein an upper end of the second heat exchanger is disposed below the reference height.

4. The heat pump device according to any one of claims 1 or 2, wherein the through hole is formed in an upper surface portion of the relay machine housing.

5. The heat pump device according to any one of claims 1 or 2, wherein the through hole is disposed in a ceiling space of the building.

6. The heat pump device according to claim 5, wherein the reference height is equal to or greater than a height from a floor surface to a ceiling surface of the building.

7. a duct communicating from the through hole to the outside of the building is provided in the ceiling space; the refrigerant pipe is passed through the duct; The heat pump device according to claim 5, further comprising an exhaust fan provided in the duct.

8. the through hole is disposed in a ceiling space of the building; a duct communicating from the through hole to the outside of the building is provided in the ceiling space; the refrigerant pipe is passed through the duct; further comprising an exhaust fan provided in the duct; The heat pump device according to claim 2, wherein the exhaust fan operates when the sensor detects the refrigerant.

9. the relay machine housing houses electrical components inside; The heat pump device according to any one of claims 1 or 2, wherein the electrical wiring connected to the electrical appliance is passed through the through hole.

10. The heat pump device according to claim 9, wherein the electrical appliance is disposed above the reference height.

Images