JP7494504B2 - Heat pump equipment - Google Patents

Description

This disclosure relates to a heat pump device.

A heat exchanger provided in a heat pump device is known that has a fuel flow path through which fuel flows and a heat medium flow path through which a heat medium flows, and exchanges heat between the fuel flowing in the fuel flow path and the heat medium flowing in the heat medium flow path, and has a partition that separates the fuel flow path from the heat medium flow path, and this partition has a first partition wall that faces the fuel and a second partition wall that is spaced from the first partition wall to form a space between the first partition wall and faces the heat medium, and the space between the first and second partition walls serves as an evacuation flow path for evacuating leaked fuel and heat medium (see, for example, Patent Document 1).

JP 2013-234626 A

However, when a heat exchanger such as that shown in Patent Document 1 is used in a heat pump device as a water heat exchanger that exchanges heat between refrigerant and water, depending on the location of the refrigerant or water leakage in the water heat exchanger, it is possible that the refrigerant or water leaking from the refrigerant or water flow path will not enter the evacuation flow path. In such a case, when refrigerant or water leakage occurs from the water heat exchanger, the leaked refrigerant or water will diffuse. Furthermore, no consideration is given to detecting the occurrence of refrigerant or water leakage from the water heat exchanger.

The present disclosure has been made to solve such problems. Its purpose is to provide a heat pump device that can quickly detect the occurrence of a refrigerant leak or water leak while suppressing the diffusion of the leaked refrigerant or water when a refrigerant leak or water leak occurs from a water heat exchanger that exchanges heat between water and a refrigerant.

The heat pump device according to the present disclosure includes a refrigerant piping in which a refrigerant is sealed, a water piping in which water is sealed, a water heat exchanger that exchanges heat between the refrigerant and the water, an air heat exchanger that exchanges heat between the refrigerant and air, a blower fan that generates an air flow that passes around the air heat exchanger, a housing that houses the refrigerant piping, the water heat exchanger, the air heat exchanger, and the blower fan, a casing that is provided separately from the housing within the housing and in which the water heat exchanger is provided, and a refrigerant sensor that detects the refrigerant inside the casing , wherein the inside of the casing is filled with air as a filler, the water heat exchanger exchanges heat between the refrigerant and the water via the filler, the inside of the casing is connected to the outside of the casing through an opening formed in the casing, and the blower fan is provided outside the casing and blows air when the refrigerant sensor detects the refrigerant .

The heat pump device according to the present disclosure has the advantage that when a refrigerant leak or water leak occurs from a water heat exchanger that exchanges heat between water and a refrigerant, the occurrence of the refrigerant leak or water leak can be detected quickly while suppressing the diffusion of the leaked refrigerant or water.

1 is a diagram showing an internal configuration of an outdoor unit and an indoor unit of an air conditioner to which a heat pump device according to a first embodiment is applied. 2 is a diagram showing a schematic configuration of a water heat exchanger provided in the heat pump device according to the first embodiment; FIG. 1 is a block diagram showing a configuration of a control system of an air conditioner to which a heat pump device according to a first embodiment is applied.

The embodiment for implementing the heat pump device according to the present disclosure will be described with reference to the attached drawings. In each drawing, the same or corresponding parts are given the same reference numerals, and duplicated descriptions are 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 the embodiments may be freely combined, any component of each embodiment may be modified, or any component of each embodiment may be omitted, within the scope of the spirit of the present disclosure.

Embodiment 1.
A first embodiment of the present disclosure will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a diagram showing the internal configuration of an outdoor unit and an indoor unit of an air conditioner to which a heat pump device is applied. Fig. 2 is a diagram showing a schematic configuration of a water heat exchanger provided in the heat pump device. And Fig. 3 is a block diagram showing the configuration of a control system of the air conditioner to which the heat pump device is applied.

The following describes an example in which the heat pump device according to this disclosure is applied to an air conditioner. This disclosure can be applied to air conditioners, including room air conditioners and commercial packaged air conditioners, as well as water heaters, showcases, refrigerators, chiller systems, and the like, and can be used in heat pump devices that have a primary circuit (refrigerant circuit) through which a refrigerant circulates and a secondary circuit (water circuit) through which water, a heat medium, circulates.

The air conditioner comprises an outdoor unit 10 and an indoor unit 20. The indoor unit 20 is installed inside the room to be air-conditioned. The outdoor unit 10 is installed outside the room. The outdoor unit 10 comprises refrigerant piping 11, a compressor 12, a four-way valve 13, an outdoor heat exchanger 14, an outdoor fan 15, an expansion valve 16, a water heat exchanger 32, and a pump 33. The indoor unit 20 comprises an indoor heat exchanger 21 and an indoor fan 22.

The refrigerant pipes 11 are provided in a circulating manner between the outdoor heat exchanger 14 of the outdoor unit 10 and the water heat exchanger 32. A refrigerant is sealed in the refrigerant pipes 11. From the viewpoint of protecting the global environment, it is desirable to use a refrigerant with a small global warming potential (GWP) for the refrigerant sealed in the refrigerant pipes 11. This refrigerant has a larger average molecular weight than air (it has a higher density than air), and has the property of sinking downward in the direction of gravity (vertical direction) in the air.

Specific examples of such refrigerants include refrigerants (mixtures) consisting of 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. These refrigerants include those that are flammable (slightly flammable or highly flammable).

The refrigerant piping 11 connects the compressor 12, the expansion valve 16, the outdoor heat exchanger 14, and the water heat exchanger 32 in a ring shape. Therefore, a refrigerant circuit is formed in which the refrigerant circulates between the outdoor heat exchanger 14 and the water heat exchanger 32. The compressor 12 is a device that compresses the supplied refrigerant to increase the pressure and temperature of the refrigerant. The compressor 12 may be, for example, a rotary compressor or a scroll compressor. The expansion valve 16 expands the refrigerant that has flowed in, reducing the pressure of the refrigerant. In other words, the expansion valve 16 is a pressure reducing device that reduces the pressure of the refrigerant.

The outdoor heat exchanger 14 is an air heat exchanger that exchanges heat between the refrigerant that flows into the outdoor heat exchanger 14 and the air. The outdoor fan 15 generates an airflow in an air passage in the outdoor unit housing described below, and blows the outside air so that it passes around the outdoor heat exchanger 14. The outdoor heat exchanger 14 exchanges heat with the outside air sent from the outdoor fan 15 by evaporating or condensing the flowed-in refrigerant, thereby cooling or heating the air. In this way, the outdoor fan 15 is a blower fan that generates an airflow that passes around the outdoor heat exchanger 14, which is an air heat exchanger.

The outdoor unit 10 and the indoor unit 20 are connected by a water pipe 31. The water pipe 31 is provided in a circulating manner between the water heat exchanger 32 of the outdoor unit 10 and the indoor heat exchanger 21 of the indoor unit 20. Water, which is a liquid heat medium, is sealed inside the water pipe 31. In other words, the water pipe 31 is a heat medium pipe with water, which is a liquid heat medium, inside. Note that water is an example of a liquid heat medium. Other liquid heat mediums such as brine can also be used.

The water heat exchanger 32 is a liquid heat exchanger that exchanges heat between the refrigerant that flows into the water heat exchanger 32 and water (liquid heat medium). The pump 33 is provided in the water piping 31. The pump 33 is for causing water, which is a liquid heat medium, to flow through the water heat exchanger 32. The water piping 31 connects the indoor heat exchanger 21, the water heat exchanger 32, and the pump 33 in a ring shape. Therefore, a water circuit is formed in which water is circulated between the indoor heat exchanger 21 and the water heat exchanger 32 by the pump 33. The pump 33 then causes water (liquid heat medium) to flow in a predetermined circulation direction through the water piping 31 (heat medium piping) thus formed in a ring shape.

The indoor heat exchanger 21 exchanges heat between the water (liquid heat medium) that flows into the indoor heat exchanger 21 and the air. The indoor fan 22 generates an airflow in an air passage in the indoor unit housing described below, and blows the outside air so that it passes around the indoor heat exchanger 21. The indoor heat exchanger 21 exchanges heat between the high-temperature or low-temperature water that flows in and the indoor air sent from the indoor fan 22, thereby exchanging heat with the indoor air.

The outdoor unit 10 includes an outdoor unit housing. Inside the outdoor unit housing, refrigerant piping 11, compressor 12, four-way valve 13, outdoor heat exchanger 14, outdoor fan 15, expansion valve 16, water heat exchanger 32, pump 33, and part of the water piping 31 are housed. The indoor unit 20 includes an indoor unit housing. Inside the indoor unit housing, indoor heat exchanger 21, indoor fan 22, and part of the water piping 31 are housed.

The outdoor unit housing has an intake port and an outlet port that connect the inside and outside of the outdoor unit housing. Inside the outdoor unit housing, an air passage is formed that runs from the intake port through the outdoor heat exchanger 14 and the outdoor fan 15 to the outlet port. In other words, this air passage is for discharging air taken in from outside the outdoor unit housing to the outside of the outdoor unit housing after heat exchange in the outdoor heat exchanger 14. The indoor unit housing also has an intake port, an outlet port, and an air passage.

The refrigerant circuit and water circuit configured in this way function as a heat pump that transfers heat between the indoor unit 20 and the outdoor unit 10 by performing heat exchange between the refrigerant and air in the outdoor heat exchanger 14, between the refrigerant and water in the water heat exchanger 32, and between the water and air in the indoor heat exchanger 21. In other words, it is an indirect type heat pump device that uses a primary circuit (refrigerant circuit) in which a flammable refrigerant circulates and a secondary circuit in which a non-flammable heat medium (here, water) circulates. In this case, by switching the four-way valve 13, the direction of circulation of the refrigerant in the refrigerant circuit can be reversed to switch between cooling operation and heating operation.

First, during cooling operation, in the primary refrigerant circuit, the refrigerant becomes hot and high pressure by the compressor 12, passes through the four-way valve 13, and flows into the outdoor heat exchanger 14. At this time, the outdoor heat exchanger 14 functions as a condenser and condenses the refrigerant that has flowed in. In other words, the high-temperature refrigerant that has flowed into the outdoor heat exchanger 14 exchanges heat with the low-temperature outside air, condenses, and becomes liquid refrigerant.

The liquid refrigerant expands through the expansion valve 16, becoming a two-phase gas-liquid refrigerant with a mixture of gas and liquid phases at low temperature and pressure. This low-temperature two-phase gas-liquid refrigerant flows into the water heat exchanger 32, where it exchanges heat with the water circulating through the water circuit and evaporates to become a gas refrigerant. This heat exchange cools the water in the water circuit. In other words, 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 back into the compressor 12, becoming a high-temperature, high-pressure refrigerant.

In the water circuit, water is circulated by the pressure generated by the pump. The water that has been cooled in the water heat exchanger 32 and has a low temperature flows from the water pipe 31 in the outdoor unit housing to the water pipe 31 in the indoor unit housing while still at a low temperature. The low-temperature water flowing through the water pipe 31 in the indoor unit housing flows into the indoor heat exchanger 21.

The water that flows into the indoor heat exchanger 21 exchanges heat with the indoor air and is heated. During this process, the indoor air is cooled. The heated water flows into the water piping 31 inside the outdoor unit housing, passes through the pump 33, and flows back into the water heat exchanger 32 where it is cooled and becomes low-temperature water.

Next, during heating operation, in the primary refrigerant circuit, the refrigerant is heated to a high temperature and pressure by the compressor 12, and passes through the four-way valve 13 and flows into the water heat exchanger 32. The refrigerant that flows into the water heat exchanger 32 exchanges heat with the water circulating in the water circuit, condensing and becoming liquid refrigerant. At this time, the water circulating in the water circuit is heated. In other words, the water heat exchanger 32 functions as a radiator and heats the water flowing in the water circuit.

The liquid refrigerant expands through the expansion valve 16 and becomes a low-temperature, low-pressure two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant flows into the outdoor heat exchanger 14. At this time, the outdoor heat exchanger 14 functions as an evaporator and evaporates the refrigerant that has flowed in. In other words, the two-phase gas-liquid refrigerant that has flowed into the outdoor heat exchanger 14 exchanges heat with the outside air and evaporates to become a gas refrigerant. The gas refrigerant flows back into the compressor 12 through the four-way valve 13 and becomes a high-temperature, high-pressure refrigerant.

In the water circuit, water is circulated by the pressure generated by the pump 33. First, the low-temperature water cooled by the water heat exchanger 32 flows at a high temperature from the water pipe 31 in the outdoor unit housing to the water pipe 31 in the indoor unit housing. The high-temperature water flowing through the water pipe 31 in the indoor unit housing flows into the indoor heat exchanger 21.

The water that flows into the indoor heat exchanger 21 exchanges heat with the indoor air and is cooled. During this process, the indoor air is heated. The cooled water flows into the water piping 31 inside the outdoor unit housing, passes through the pump 33, and flows back into the water heat exchanger 32 where it is heated and becomes high-temperature water.

The air conditioner to which the heat pump device according to this embodiment is applied further includes a refrigerant shutoff valve 17 and a water shutoff valve 34. The refrigerant shutoff valve 17 is provided in the refrigerant piping 11. In the configuration example described here, the refrigerant shutoff valves 17 are provided at the inlet portion of the refrigerant piping 11 to the water heat exchanger 32 and at the outlet portion from the water heat exchanger 32. Under normal circumstances, these refrigerant shutoff valves 17 are open. By closing these refrigerant shutoff valves 17, the water heat exchanger 32 can be separated from the water circuit.

Water shutoff valves 34 are provided in the water piping 31. In the configuration example described here, water shutoff valves 34 are provided at the inlet portion of the water piping 31 to the water heat exchanger 32 and the outlet portion from the water heat exchanger 32. Under normal circumstances, these water shutoff valves 34 are open. By closing these water shutoff valves 34, the water heat exchanger 32 can be separated from the water circuit. It is preferable that these refrigerant shutoff valves 17 and water shutoff valves 34 are provided, but they are not necessarily required.

As shown in FIG. 2, the air conditioner to which the heat pump device according to this embodiment is applied further includes a casing 40. The casing 40 is housed in the outdoor unit housing of the outdoor unit 10. The water heat exchanger 32 is provided inside the casing 40. The inside of the casing 40 is filled with a filler. The filler is a gas or liquid. For example, air, a gas such as helium, water, various oils and fats that are liquid at room temperature, etc. can be used as the filler. When air is used as the filler, the inside of the casing 40 may be open to the outside through an opening formed in the casing 40.

The water heat exchanger 32 of this embodiment is a so-called double-wall type, for example, a plate heat exchanger. The water heat exchanger 32 has a refrigerant layer 32a and a water layer 32b. The refrigerant layer 32a is a plate through which the refrigerant flowing into the water heat exchanger 32 from the refrigerant pipe 11 flows. The water layer 32b is a plate through which the water flowing into the water heat exchanger 32 from the water pipe 31 flows. The refrigerant layer 32a and the water layer 32b of the water heat exchanger 32 are arranged alternately inside the casing 40. The adjacent refrigerant layer 32a and the water layer 32b are completely separated by a double wall. A layer filled with a filler in the casing 40 is formed in the double wall between the refrigerant layer 32a and the water layer 32b. And the water heat exchanger 32 of this embodiment exchanges heat between the refrigerant in the refrigerant layer 32a and the water in the water layer 32b through the filler.

The air conditioner to which the heat pump device according to this embodiment is applied further includes a refrigerant sensor 41, a water leakage sensor 42, and a pressure sensor 43. The refrigerant sensor 41 is a sensor that detects the refrigerant inside the casing 40. The refrigerant sensor 41 is installed in the casing 40. The refrigerant sensor 41 is capable of detecting at least the same type of refrigerant as that sealed in the refrigerant pipe 11. The refrigerant sensor 41 can be of various types, such as catalytic combustion type, semiconductor type, heat conduction type, low potential electrolysis type, and infrared type. The refrigerant sensor 41 converts the refrigerant concentration inside the casing 40 into an electrical signal and outputs it.

Also, an oxygen sensor can be used as the refrigerant sensor 41. When an oxygen sensor is used, the oxygen concentration is calculated based on the sensor output, and the concentration of the inflowing gas is calculated assuming that the decrease in oxygen concentration is due to the inflowing gas, thereby indirectly detecting the concentration of the inflowing gas, i.e., the refrigerant. As the oxygen sensor, for example, various types such as a galvanic cell type, a polaro type, and a zirconia type can be used.

The water leakage sensor 42 is a sensor that detects water inside the casing 40. The water leakage sensor 42 detects water inside the casing 40 using, for example, a pair of electrodes, and converts the presence or absence of water inside the casing 40 into an electrical signal for output. The pressure sensor 43 measures the pressure of the filling material inside the casing 40 using a pressure-sensitive element via a diaphragm or the like, and converts it into an electrical signal for output.

In the configuration example described here, three types of sensors are provided: the refrigerant sensor 41, the water leakage sensor 42, and the pressure sensor 43. However, it is not necessary to provide all of these sensors. The heat pump device only needs to have at least one of the refrigerant sensor 41, the water leakage sensor 42, and the pressure sensor 43.

The configuration of the control system of an air conditioner to which the heat pump device according to this embodiment is applied is shown in Figure 3. As shown in the figure, the air conditioner according to this embodiment includes a leak detection unit 51, a memory unit 52, an alarm unit 53, and a control unit 54. Each of these units is configured, for example, by a circuit mounted on the control device of the air conditioner.

The leak detection unit 51 detects the occurrence of leakage of either or both of the refrigerant and water inside the casing 40 based on the detection results of the refrigerant sensor 41, the water leakage sensor 42, and the pressure sensor 43. As described above, the refrigerant sensor 41 can detect the refrigerant directly or indirectly. The refrigerant sensor 41 then outputs a detection signal according to the concentration of the detected refrigerant.

The detection signal output from the refrigerant sensor 41 is input to the leak detection unit 51. The leak detection unit 51 determines whether the refrigerant concentration indicated by the detection signal from the refrigerant sensor 41 is equal to or greater than the refrigerant leak judgment reference value. The refrigerant leak judgment reference value is a preset value. The preset refrigerant leak judgment reference value is stored in the memory unit 52. The leak detection unit 51 makes a judgment by comparing the refrigerant leak judgment reference value acquired from the memory unit 52 with the refrigerant concentration indicated by the detection signal from the refrigerant sensor 41.

When the refrigerant concentration indicated by the detection signal from the refrigerant sensor 41 is equal to or greater than the refrigerant leakage judgment reference value, the leak detection unit 51 outputs a refrigerant leakage detection signal to the control unit 54. The refrigerant leakage detection signal is a signal indicating that a refrigerant leakage has been detected within the casing 40. In this manner, when the heat pump device is equipped with the refrigerant sensor 41, the leak detection unit 51 detects a refrigerant leakage within the casing 40.

As described above, the water leakage sensor 42 outputs a detection signal according to whether water is detected. The detection signal output from the water leakage sensor 42 is input to the leakage detection unit 51. When a detection signal indicating the detection of water is input from the water leakage sensor 42, the leakage detection unit 51 outputs a water leakage detection signal to the control unit 54. The water leakage detection signal is a signal indicating that a water leakage has been detected within the casing 40. When the heat pump device is equipped with the water leakage sensor 42, the leakage detection unit 51 detects water leakage inside the casing 40 in this manner.

As described above, the pressure sensor 43 outputs a detection signal corresponding to the detected pressure of the filling material. The detection signal output from the pressure sensor 43 is input to the leak detection unit 51. The leak detection unit 51 judges whether the pressure indicated by the detection signal from the pressure sensor 43 is equal to or greater than the leak judgment reference value. The leak judgment reference value is a preset value. The leak judgment reference value should be at least equal to or greater than atmospheric pressure, and should be set taking into account the temperature environment and tolerance. The preset leak judgment reference value is stored in the memory unit 52. The leak detection unit 51 makes a judgment by comparing the leak judgment reference value acquired from the memory unit 52 with the pressure indicated by the detection signal from the pressure sensor 43.

Then, when the pressure indicated by the detection signal from the pressure sensor 43 is equal to or greater than the leak judgment reference value, the leak detection unit 51 outputs a leak detection signal to the control unit 54. The leak detection signal is a signal indicating that at least one of a refrigerant leak and a water leak has been detected within the casing 40. In this manner, when the heat pump device is equipped with the pressure sensor 43, the leak detection unit 51 detects a leak of either or both of the refrigerant and water within the casing 40.

In an air conditioner to which a heat pump device configured as described above is applied, low-temperature refrigerant flows into the water heat exchanger 32 during cooling operation, etc. At this time, refrigerant below 0°C (the freezing point of water) may flow into the water heat exchanger 32, causing the water circulating through the water circuit to freeze, and the water heat exchanger 32 may be damaged due to the volume expansion of the water caused by freezing. In addition, the water heat exchanger 32 may also be damaged due to, for example, aging deterioration, external stress, etc.

As described above, the water heat exchanger 32 in this embodiment is covered by the casing 40, and the adjacent refrigerant layer 32a and water layer 32b are completely separated by a double wall. The water heat exchanger 32 exchanges heat between the refrigerant flowing through the refrigerant layer 32a and the water flowing through the water layer 32b through the filler in the casing 40. For this reason, even if the water layer 32b side of the water heat exchanger 32 is damaged, for example, the refrigerant does not enter the water circuit, and water leaks from the water layer 32b, i.e., the water heat exchanger 32, into the casing 40. Also, even if the refrigerant layer 32a side of the water heat exchanger 32 is damaged due to aging, external stress, corrosion, etc., the refrigerant does not enter the water circuit, and the refrigerant leaks from the refrigerant layer 32a, i.e., the water heat exchanger 32, into the casing 40.

By providing sensors (one or more of the refrigerant sensor 41, water leakage sensor 42, and pressure sensor 43) for detecting leakage of either or both of the refrigerant and water within the casing 40 that houses the water heat exchanger 32, when a refrigerant leak or water leak occurs from the water heat exchanger 32, the leaked refrigerant and water can be contained within the casing 40, preventing the diffusion of the leaked refrigerant and water, and quickly detecting the occurrence of a refrigerant leak or water leak from the water heat exchanger 32.

The control unit 54 controls the overall operation of the air conditioner by controlling the actuators equipped in the air conditioner. In addition to the outdoor fan 15, pump 33, refrigerant shutoff valve 17, and water shutoff valve 34 explicitly shown in FIG. 3, the control objects of the control unit 54 include, for example, the compressor 12, four-way valve 13, and indoor fan 22.

The control unit 54 operates the outdoor fan 15 when at least one of the refrigerant leakage detection signal and the leakage detection signal is input from the leakage detection unit 51. That is, when the heat pump device is equipped with the refrigerant sensor 41, the outdoor fan 15, which is a blower fan, blows air when the refrigerant sensor 41 detects a refrigerant leakage. Also, when the heat pump device is equipped with the pressure sensor 43, the outdoor fan 15, which is a blower fan, blows air when the leakage detection unit 51 detects a leakage of one or both of the refrigerant and water from the detection result of the pressure sensor 43. As described above, when the filling body in the casing 40 is air, the inside of the casing 40 may be connected to the outside. In this case, when the refrigerant leaks from the refrigerant layer 32a of the water heat exchanger 32 in the casing 40, the leaked refrigerant flows out to the outside of the casing 40. Therefore, the outdoor fan 15 stirs the air inside the housing of the outdoor unit 10 to diffuse the leaked refrigerant, preventing the leaked refrigerant from accumulating inside the housing of the outdoor unit 10 and causing the refrigerant concentration to increase.

If the heat pump device is equipped with a refrigerant sensor 41, when a refrigerant leakage detection signal is input from the leakage detection unit 51, the control unit 54 may stop the compressor 12 if the compressor 12 is in operation. In this way, the amount of refrigerant leakage in the event of a refrigerant leakage in the casing 40 can be suppressed.

In addition, if the heat pump device is equipped with a water leak sensor 42, when a water leak detection signal is input from the leak detection unit 51, the control unit 54 may stop the pump 33 if the pump 33 is in operation. In this way, the amount of water leakage when a leak occurs inside the casing 40 can be suppressed.

When at least one of a refrigerant leakage detection signal and a water leakage detection signal is input from the leakage detection unit 51, the control unit 54 closes one or both of the refrigerant shutoff valve 17 and the water shutoff valve 34. That is, when the heat pump device is equipped with a refrigerant sensor 41, the control unit 54 closes the refrigerant shutoff valve 17 when a refrigerant leakage detection signal is input from the leakage detection unit 51. Therefore, when the refrigerant sensor 41 detects a refrigerant leakage, the refrigerant shutoff valve 17 shuts off the refrigerant piping 11. This separates the water heat exchanger 32 from the refrigerant circuit. In this way, the amount of refrigerant leakage when a refrigerant leakage occurs in the casing 40 can be suppressed.

In addition, if the heat pump device is equipped with a water leak sensor 42, the control unit 54 closes the water shutoff valve 34 when a water leak detection signal is input from the leak detection unit 51. Therefore, the water shutoff valve 34 shuts off the water piping 31 when the water leak sensor 42 detects a water leak. This separates the water heat exchanger 32 from the water circuit. In this way, the amount of water leakage when a leak occurs inside the casing 40 can be suppressed.

When the leak detection unit 51 outputs at least one of a refrigerant leak detection signal, a water leak detection signal, and a leak detection signal, the notification unit 53 notifies the user or worker of the same and encourages ventilation and repairs. The notification unit 53 is equipped with a speaker for sounding or an LED for light notifying that a leak of either or both of the refrigerant and water has been detected inside the casing 40. The notification unit 53 is provided, for example, in the housing of the indoor unit 20, the remote control of the air conditioner, etc.

Furthermore, the control unit 54 may stop normal operation of the air conditioner when at least one of a refrigerant leak detection signal, a water leak detection signal, and a leak detection signal is input from the leak detection unit 51. In this case, it is preferable that the control unit 54 does not return to normal operation until inspection and repair work by a specialized maintenance technician or the like is completed.

If water leaks from the water heat exchanger 32 or if water is generated in the water heat exchanger 32 due to condensation, the water will flow vertically downward due to gravity and will tend to accumulate on the bottom surface of the casing 40. If the refrigerant sensor 41 and pressure sensor 43 are located on the bottom surface of the casing 40, water may adhere to the sensors, which may cause sensor abnormalities and reduced detection accuracy. Therefore, it is advisable to install the refrigerant sensor 41 and pressure sensor 43 at a location other than the bottom surface of the casing 40, i.e., on the side or top surface of the casing 40. In this way, adhesion of water to the refrigerant sensor 41 and pressure sensor 43 can be suppressed, and sensor abnormalities and reduced sensor detection accuracy due to the influence of water in the casing 40 can be prevented.

Also, by installing the water leakage sensor 42 at a location other than the bottom surface of the casing 40, i.e., on the side or top surface of the casing 40, false detection due to condensation water generated in the water heat exchanger 32 can be suppressed. However, as described above, water leaking from the water heat exchanger 32 also flows vertically downward, just like condensation water. Therefore, the location of the water leakage sensor 42 should be the side surface of the casing 40, etc., below the lower end of the water heat exchanger 32 while avoiding the bottom surface of the casing 40. In this way, it is possible to efficiently detect water leakage from the water heat exchanger 32 while suppressing false detection due to condensation water. Note that a drain hole for condensation water may be provided on the bottom surface of the casing 40.

REFERENCE SIGNS LIST 10 Outdoor unit 11 Refrigerant piping 12 Compressor 13 Four-way valve 14 Outdoor heat exchanger 15 Outdoor fan 16 Expansion valve 17 Refrigerant shutoff valve 20 Indoor unit 21 Indoor heat exchanger 22 Indoor fan 31 Water piping 32 Water heat exchanger 32a Refrigerant layer 32b Water layer 33 Pump 34 Water shutoff valve 40 Casing 41 Refrigerant sensor 42 Water leakage sensor 43 Pressure sensor 51 Leak detection unit 52 Memory unit 53 Notification unit 54 Control unit

Claims (8)

A refrigerant pipe filled with a refrigerant;
A water pipe filled with water;
a water heat exchanger for exchanging heat between the refrigerant and the water;
an air heat exchanger for exchanging heat between the refrigerant and air;
A blower fan that generates an air flow passing around the air heat exchanger;
a housing that accommodates the refrigerant piping, the water heat exchanger, the air heat exchanger, and the blower fan therein;
A casing provided separately from the housing within the housing and having the water heat exchanger provided therein;
a refrigerant sensor that detects the refrigerant inside the casing ,
The inside of the casing is filled with air as a filler,
The water heat exchanger exchanges heat between the refrigerant and the water via the filler,
The inside of the casing is in communication with the outside of the casing through an opening formed in the casing,
The blower fan is provided outside the casing, and the heat pump device blows air when the refrigerant sensor detects the refrigerant . The heat pump apparatus according to claim 1 , wherein the refrigerant sensor is provided at a location other than a bottom surface of the casing. The heat pump apparatus according to claim 1 or 2 , further comprising a refrigerant shutoff valve that shuts off the refrigerant pipe when the refrigerant sensor detects the refrigerant. The heat pump apparatus according to claim 1 , further comprising a water leakage sensor that detects the water inside the casing . The heat pump apparatus according to claim 4 , wherein the water leakage sensor is installed at a location other than a bottom surface of the casing. The heat pump apparatus according to claim 4 or 5 , wherein the water leakage sensor is disposed at a position in the casing below a lower end of the water heat exchanger. The heat pump apparatus according to claim 4 , further comprising a water shutoff valve that shuts off the water piping when the water leakage sensor detects the water. A pump is further provided for causing the water to flow through the water pipe and the water heat exchanger.
The heat pump apparatus according to claim 4 , wherein the pump is stopped when the water leakage sensor detects the water.

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