JP6247980B2 - Heat pump heating device - Google Patents

Description

  The present invention relates to a heat pump heating apparatus.

  In Patent Document 1, a condenser that condenses the refrigerant by exchanging heat between the refrigerant and the fluid to be heated, a decompressor that decompresses the refrigerant from the condenser, an evaporator that evaporates the refrigerant from the decompressor, A heat pump heating device is disclosed that includes a compressor that pressurizes the refrigerant from the evaporator and sends it to the condenser, and a temperature detection means that is disposed in the refrigerant flow path in the condenser and detects the temperature of the refrigerant. In this heat pump heating device, when the temperature detected by the temperature detection means (that is, the refrigerant condensing temperature) exceeds a predetermined temperature, the rotation speed of the compressor is decreased to increase the pressure of the refrigerant discharged from the compressor. Suppress.

JP 2004-226036 A

  In the heat pump heating device, the dryness of the refrigerant sucked into the compressor is low, and the refrigerant discharged from the compressor may be in a gas-liquid two-phase state. If the compressor is continuously operated in this state, the compression ratio is increased and the pressure in the cylinder is increased accordingly, and the deterioration of the mechanical parts of the compressor is accelerated. However, in the prior art, even if the dryness of the refrigerant sucked into the compressor is low and the refrigerant discharged from the compressor is in a gas-liquid two-phase state, the heat pump heating device is operated so as to eliminate the state I couldn't make it happen.

  The present specification provides a technique for solving the above problems. In the present specification, in the heat pump heating device, when the dryness of the refrigerant sucked into the compressor is low and the refrigerant discharged from the compressor is in a gas-liquid two-phase state, the state can be eliminated I will provide a.

  The heat pump heating apparatus disclosed in this specification includes a condenser that exchanges heat between a refrigerant and a fluid to be heated to condense the refrigerant, a decompressor that decompresses the refrigerant from the condenser, and a refrigerant from the decompressor. An evaporator that evaporates, a compressor that pressurizes the refrigerant from the evaporator and sends it to the condenser, and a first temperature detection that is disposed in the refrigerant flow path between the compressor and the condenser and detects the temperature of the refrigerant And a second temperature detecting means arranged in the refrigerant flow path in the condenser and detecting the temperature of the refrigerant. The heat pump heating device is configured to increase the dryness of the refrigerant sucked into the compressor when the difference between the detected temperature of the first temperature detecting means and the detected temperature of the second temperature detecting means is less than a predetermined lower limit value. Increase the degree of control.

  When the refrigerant sucked into the compressor is low in dryness and the refrigerant discharged from the compressor is in a gas-liquid two-phase state, the temperature of the refrigerant does not decrease even if the refrigerant dissipates heat. The detected temperature and the temperature detected by the second temperature detecting means are substantially the same. On the other hand, when the dryness of the refrigerant sucked into the compressor is high and the refrigerant discharged from the compressor is in a gas single-phase state, the temperature of the refrigerant decreases due to the heat dissipation of the refrigerant. The temperature detected at is higher than the temperature detected by the second temperature detecting means. In the above heat pump heating apparatus, when the difference between the detected temperature of the first temperature detecting means and the detected temperature of the second temperature detecting means is less than the predetermined lower limit value, the refrigerant that increases the dryness of the refrigerant sucked into the compressor Perform dryness increase control. According to said heat pump heating apparatus, when the dryness of the refrigerant | coolant suck | inhaled by a compressor is low and the refrigerant | coolant discharged from a compressor exists in a gas-liquid two-phase state, the state can be eliminated.

  Further, according to the above heat pump heating device, the second temperature detection means measures the temperature of the refrigerant after the heat is radiated to some extent by the condenser, so the refrigerant discharged from the compressor is in a gas single phase state. In this case, the difference between the detected temperature of the first temperature detecting means and the detected temperature of the second temperature detecting means can be clearly detected.

  Another heat pump heating apparatus disclosed in this specification includes a condenser that exchanges heat between a refrigerant and a fluid to be heated to condense the refrigerant, a decompressor that decompresses the refrigerant from the condenser, and a An evaporator that evaporates the refrigerant, a compressor that pressurizes the refrigerant from the evaporator and sends it to the condenser, and a refrigerant flow path between the compressor and the condenser, and detects the temperature of the refrigerant. The temperature detection means is disposed downstream of the first temperature detection means of the refrigerant flow path between the compressor and the condenser, and includes a second temperature detection means for detecting the temperature of the refrigerant. The heat pump heating device is configured to increase the dryness of the refrigerant sucked into the compressor when the difference between the detected temperature of the first temperature detecting means and the detected temperature of the second temperature detecting means is less than a predetermined lower limit value. Increase the degree of control.

  Even in the refrigerant flow path between the compressor and the condenser, the refrigerant dissipates heat, albeit slightly. Therefore, also in the above heat pump heating device, when the dryness of the refrigerant sucked into the compressor is low and the refrigerant discharged from the compressor is in a gas-liquid two-phase state, the temperature detected by the first temperature detecting means When the temperature detected by the second temperature detection means is substantially the same, the dryness of the refrigerant sucked into the compressor is high, and the refrigerant discharged from the compressor is in a gas single-phase state, the temperature is detected by the first temperature detection means The detected temperature is higher than the temperature detected by the second temperature detecting means. According to said heat pump heating apparatus, when the dryness of the refrigerant | coolant suck | inhaled by a compressor is low and the refrigerant | coolant discharged from a compressor exists in a gas-liquid two-phase state, the state can be eliminated.

  When both the first temperature detection means and the second temperature detection means are arranged in the refrigerant flow path between the compressor and the condenser as in the heat pump heating device described above, the second temperature detection means is condensed. The measurement conditions of the respective temperature detection means are almost the same without being affected by the temperature of the heated fluid of the vessel, so that the measurement error due to the difference in measurement conditions between the first temperature detection means and the second temperature detection means The influence of can be eliminated.

  Said heat pump heating apparatus is further provided with the ventilation means which ventilates to an evaporator, and can be comprised so that the ventilation volume of a ventilation means may be increased in refrigerant | coolant dryness raise control.

  According to the heat pump heating device described above, in the refrigerant dryness increase control, the evaporation of the refrigerant in the evaporator is promoted by the increase in the blowing amount of the blower means, and the dryness of the refrigerant sucked into the compressor can be increased. . The state where the dryness of the refrigerant sucked into the compressor is low can be solved.

  Said heat pump heating apparatus can be comprised so that the rotation speed of a compressor may be reduced in refrigerant | coolant dryness raise control.

  According to the heat pump heating device described above, in the refrigerant dryness increase control, it is possible to increase the dryness of the refrigerant sucked into the compressor by reducing the circulating flow rate of the refrigerant by reducing the rotation speed of the compressor. The state where the dryness of the refrigerant sucked into the compressor is low can be solved.

  Said heat pump heating apparatus is a throttle valve in which the decompressor was provided in the refrigerant | coolant flow path, Comprising: In refrigerant | coolant dryness raise control, it can comprise so that the opening degree of a throttle valve may be made small.

  According to the above heat pump heating device, in the refrigerant dryness increase control, it is possible to increase the dryness of the refrigerant sucked into the compressor by decreasing the circulating flow rate of the refrigerant by reducing the opening of the throttle valve. . The state where the dryness of the refrigerant sucked into the compressor is low can be solved.

  According to the heat pump heating device disclosed in this specification, when the dryness of the refrigerant sucked into the compressor is low and the refrigerant discharged from the compressor is in a gas-liquid two-phase state, the state can be eliminated. it can.

It is a figure which shows typically the structure of the hot water supply system 2 in which the heat pump heating apparatus 4 was integrated. It is a figure which shows an example of the temperature change of the refrigerating cycle of the refrigerant | coolant in the heat pump heating apparatus 4, and hot water supply water. It is a figure which shows another example of the refrigerating cycle of the refrigerant | coolant in the heat pump heating apparatus 4, and the temperature change of the hot water supply water. It is a figure which shows typically another structure of the hot water supply system 2 in which the heat pump heating apparatus 4 was integrated.

(Example)
As shown in FIG. 1, the hot water supply system 2 mainly includes a heat pump heating device 4, a hot water storage tank 8, a circulation pump 10, a mixing valve 12, a burner heating device 14, a bypass valve 16, and a control device 18. I have. The hot water supply system 2 heats water supplied from a water supply source such as a water supply by using the heat pump heating device 4 and / or the burner heating device 14 as a heating source, and supplies water adjusted to a hot water supply set temperature.

The heat pump heating device 4 includes a refrigerant circulation path 20 for circulating a refrigerant (for example, an HFC refrigerant such as R32 and R410A, and a CO ₂ refrigerant such as R744), an evaporator 22, a fan 24, a compressor 26, and a condenser. 28 and a decompressor 30.

  The evaporator 22 is a gas-liquid heat exchanger that exchanges heat between the outside air blown by the fan 24 and the refrigerant in the refrigerant circulation path 20. The evaporator 22 is supplied with a refrigerant in a low-pressure and low-temperature liquid state after passing through the decompressor 30. The evaporator 22 heats the refrigerant by exchanging heat between the refrigerant and the outside air. The refrigerant is vaporized by being heated, and is in a gas state at a relatively high temperature and a low pressure.

  The compressor 26 is a compressor having a lift type check valve. The refrigerant after passing through the evaporator 22 is supplied to the compressor 26. That is, the compressor 26 is supplied with a relatively high temperature and low pressure gaseous refrigerant. When the refrigerant is compressed by the compressor 26, the refrigerant is in a high-temperature and high-pressure gaseous state. The compressor 26 sends the compressed high-temperature and high-pressure gaseous refrigerant to the condenser 28. A first temperature sensor 31 that detects the temperature of the refrigerant is provided in the refrigerant circuit 20 between the compressor 26 and the condenser 28. In the present embodiment, the first temperature sensor 31 is provided in the refrigerant circuit 20 near the discharge port of the compressor 26.

  The condenser 28 is supplied with a high-temperature and high-pressure gaseous refrigerant sent out from the compressor 26. The condenser 28 is a liquid-liquid heat exchanger that performs heat exchange between the refrigerant in the refrigerant circuit 20 and the water in the hot water supply water circuit 6 (hereinafter also referred to as hot water supply water). As a result of the heat exchange in the condenser 28, the refrigerant is deprived of heat and condensed. Thereby, a refrigerant | coolant will be in a high-pressure liquid state with a comparatively low temperature. Note that a second temperature sensor 32 that detects the temperature of the refrigerant is provided in the refrigerant circulation path 20 in the condenser 28.

  The decompressor 30 is supplied with a relatively low-temperature and high-pressure liquid refrigerant after passing through the condenser 28. The decompressor 30 of the present embodiment is a throttle valve provided in the refrigerant circuit 20. The refrigerant is depressurized by passing through the decompressor 30, and becomes a low-temperature and low-pressure liquid state. The refrigerant that has passed through the decompressor 30 is sent to the evaporator 22 as described above.

  When the compressor 26 is operated in the heat pump heating device 4, the refrigerant in the refrigerant circulation path 20 circulates in the order of the evaporator 22, the compressor 26, the condenser 28, and the decompressor 30. When the heat pump heating device 4 operates, the hot water in the hot water supply water circulation path 6 is heated in the condenser 28.

  The hot water storage tank 8 stores hot water supply water heated by the heat pump heating device 4. The hot water tank 8 is a closed type, and the outside is covered with a heat insulating material. Hot water supply water is stored in the hot water tank 8 until it is full.

  The hot water supply water circulation path 6 has an upstream end connected to the lower part of the hot water storage tank 8, passes through the condenser 28 of the heat pump heating device 4, and a downstream end is connected to the upper part of the hot water storage tank 8. A circulation pump 10 is attached to the hot water supply water circulation path 6. When the heat pump heating device 4 is operated and the circulation pump 10 is driven, the hot water for the hot water in the lower part of the hot water tank 8 is sent to the condenser 28, and the hot water for the hot water heated by the condenser 28 is supplied to the upper part of the hot water tank 8. Returned. Inside the hot water storage tank 8, a temperature stratification is formed in which a layer of high-temperature hot water supply water is stacked on a layer of low-temperature hot water supply water.

  The upstream end of the water supply channel 34 is connected to an external water supply, and receives tap water as hot water supply water. The downstream side of the water supply path 34 branches into a hot water tank introduction path 36 and a hot water tank bypass path 38. The downstream end of the hot water tank introduction path 36 is connected to the lower part of the hot water tank 8. The downstream end of the hot water tank bypass passage 38 is connected to the mixing valve 12. An upstream end of the hot water tank outlet 40 is connected to the upper part of the hot water tank 8. A downstream side of the hot water tank outlet 40 is connected to the mixing valve 12.

  The mixing valve 12 mixes the hot water for hot water from the upper part of the hot water tank 8 flowing through the hot water tank outlet path 40 and the low temperature hot water from the water path 34 for flowing through the hot water tank bypass path 38 to the first hot water path. 42. In the mixing valve 12, the ratio of the flow rate of hot water flowing from the hot water tank outlet path 40 to the first hot water path 42 and the flow rate of hot water flowing from the hot water tank bypass path 38 to the first hot water path 42 are adjusted. The downstream side of the first hot water supply passage 42 branches into a burner heating passage 44 and a burner bypass passage 46. A burner heating device 14 is attached to the burner heating path 44. The burner heating device 14 burns fuel such as gas and heats hot water supply water flowing through the burner heating path 44. A bypass valve 16 is attached to the burner bypass 46. The burner heating path 44 and the burner bypass path 46 merge at their downstream ends and are connected to the upstream end of the second hot water supply path 48. Water for hot water adjusted to a hot water supply set temperature is supplied from the second hot water supply path 48 to a hot water supply location such as a kitchen hot water tap and a shower in the bathroom.

  The control device 18 controls operations of the fan 24, the compressor 26, the decompressor 30, the circulation pump 10, the mixing valve 12, the burner heating device 14, the bypass valve 16, and the like.

  Hereinafter, a hot water supply operation and a heat storage operation performed by the hot water supply system 2 will be described.

  The hot water supply operation is an operation in which hot water supply water adjusted to a hot water supply set temperature is supplied to the second hot water supply passage 48. The hot water supply operation can be performed in parallel with the heat storage operation described later. When the supply of hot water in a hot water tap or shower is started, tap water flows from the water supply channel 34 into the lower part of the hot water tank 8 due to the water pressure from the water supply channel 34. At the same time, hot water supply water in the upper part of the hot water storage tank 8 is supplied to the second hot water supply path 48 via the hot water tank outlet path 40, the first hot water supply path 42, the burner heating path 44, and the burner bypass path 46. When the temperature of the hot water supplied from the hot water storage tank 8 to the hot water tank outlet path 40 is higher than the set hot water temperature, the control device 18 drives the mixing valve 12 to connect the first hot water path from the hot water tank bypass path 38. Into 42, low-temperature hot water supply water is introduced. The control device 18 adjusts the opening degree of the mixing valve 12 so that the temperature of the hot water supply water supplied to the second hot water supply passage 48 becomes the target hot water supply set temperature. On the other hand, the control device 18 heats the hot water supply water by the burner heating device 14 when the temperature of the hot water supply water supplied from the hot water storage tank 8 to the hot water tank lead-out path 40 is lower than the hot water supply set temperature. The control device 18 controls the output of the burner heating device 14 so that the temperature of the hot water supply water supplied to the second hot water supply passage 48 becomes the target hot water supply set temperature.

  In the heat storage operation, the hot water supply water in the hot water storage tank 8 is heated by the heat pump heating device 4, and the hot water supply water that has reached a high temperature is returned to the hot water storage tank 8. When starting the heat storage operation, the control device 18 drives the fan 24 and the compressor 26 to operate the heat pump heating device 4 and drives the circulation pump 10. By driving the compressor 26, the refrigerant in the refrigerant circuit 20 circulates in the order of the evaporator 22, the compressor 26, the condenser 28, and the decompressor 30. Further, the hot water supply water in the hot water storage tank 8 circulates in the hot water supply water circulation path 6 by driving the circulation pump 10. That is, the hot water supply water existing in the lower part of the hot water storage tank 8 is introduced into the hot water supply water circulation path 6, the introduced hot water supply water is heated by the condenser 28, and the heated hot water supply water is returned to the upper part of the hot water storage tank 8. . As a result, hot water supply water is stored in the hot water tank 8. When the hot water storage tank 8 is fully charged with hot hot water, the heat storage operation is terminated.

  During the heat storage operation, the control device 18 determines the rotational speed of the fan 24, the rotational speed of the compressor 26 based on the temperature detected by the first temperature sensor 31 and the temperature detected by the second temperature sensor 32, The opening degree of the throttle valve which is the decompressor 30 is adjusted.

  2 and 3, the thick solid line 50 indicates the refrigerant refrigeration cycle in the heat pump heating device 4, the thick broken line 52 indicates the temperature rise of the hot water supply water in the heat pump heating device 4, and the white circle 54 indicates the first temperature. The temperature detected by the sensor 31 is shown, and the white circle 56 shows the temperature detected by the second temperature sensor 32.

  As shown in FIG. 2, when the dryness of the refrigerant sucked into the compressor 26 is high and the refrigerant discharged from the compressor 26 is in a gas single phase state, the temperature detected by the second temperature sensor 32 is the first temperature. It becomes lower than the temperature detected by the temperature sensor 31. On the other hand, as shown in FIG. 3, when the dryness of the refrigerant sucked into the compressor 26 is low and the refrigerant discharged from the compressor 26 is in a gas-liquid two-phase state, it is detected by the second temperature sensor 32. The detected temperature substantially matches the temperature detected by the first temperature sensor 31. If the compressor 26 is continuously operated in the state as shown in FIG. 3, the compression ratio is increased and the pressure in the cylinder is increased accordingly, and the deterioration of the mechanical parts of the compressor 26 is accelerated. Therefore, in the hot water supply system 2 of the present embodiment, the difference between the temperature detected by the first temperature sensor 31 and the temperature detected by the second temperature sensor 32 is less than a predetermined lower limit (for example, 0.5 ° C.). Next, the refrigerant dryness increase control for increasing the dryness of the refrigerant sucked into the compressor 26 is performed.

  Specifically, the control device 18 increases the rotational speed of the fan 24 and increases the amount of air blown to the evaporator 22 in the refrigerant dryness increase control. Thereby, the evaporation of the refrigerant in the evaporator 22 is promoted, and the dryness of the refrigerant sucked into the compressor 26 can be increased. The state where the dryness of the refrigerant sucked into the compressor 26 is low can be eliminated.

  And / or the control apparatus 18 reduces the rotation speed of the compressor 26 in refrigerant dryness raise control. Thereby, the circulation flow rate of the refrigerant | coolant in the heat pump heating apparatus 4 can be reduced, and the dryness of the refrigerant | coolant suck | inhaled by the compressor 26 can be raised. The state where the dryness of the refrigerant sucked into the compressor 26 is low can be eliminated.

  And / or the control apparatus 18 makes the opening degree of the throttle valve which is the decompressor 30 small in refrigerant | coolant dryness raise control. Thereby, the circulation flow rate of the refrigerant | coolant in the heat pump heating apparatus 4 can be reduced, and the dryness of the refrigerant | coolant suck | inhaled by the compressor 26 can be raised. The state where the dryness of the refrigerant sucked into the compressor 26 is low can be eliminated.

  In this embodiment, a compressor having a lift type check valve is used as the compressor 26. By adopting such a configuration, even when the dryness of the refrigerant sucked into the compressor 26 is lowered and the pressure in the cylinder suddenly rises, the lift type check valve is opened to increase the pressure in the cylinder. Can be relaxed.

  In the above embodiment, the second temperature sensor 32 is provided in the refrigerant circulation path 20 in the condenser 28. In such a configuration, the second temperature sensor 32 measures the temperature of the refrigerant after it has radiated heat to some extent by the condenser 28. Therefore, when the refrigerant discharged from the compressor 26 is in a gas single-phase state, The difference between the temperature detected by the first temperature sensor 31 and the temperature detected by the second temperature sensor 32 can be clearly detected.

  Unlike the above embodiment, as shown in FIG. 4, the second temperature sensor 32 may be arranged downstream of the first temperature sensor 31 in the refrigerant circulation path 20 between the compressor 26 and the condenser 28. Good. In the example shown in FIG. 4, the first temperature sensor 31 is provided in the refrigerant circuit 20 near the discharge port of the compressor 26, and the second temperature sensor 32 is provided in the refrigerant circuit 20 near the inlet of the condenser 28. It has been. Even in the refrigerant circuit 20 between the compressor 26 and the condenser 28, the refrigerant dissipates heat, albeit slightly. Therefore, even when the configuration shown in FIG. 4 is adopted, the first temperature sensor 31 detects when the dryness of the refrigerant sucked into the compressor 26 is low and the refrigerant discharged from the compressor 26 is in a gas-liquid two-phase state. The temperature detected by the second temperature sensor 32 is substantially the same, the dryness of the refrigerant sucked into the compressor 26 is high, and the refrigerant discharged from the compressor 26 is in a gas single-phase state. The temperature detected by the first temperature sensor 31 is higher than the temperature detected by the second temperature sensor 32. Also in the configuration shown in FIG. 4, when the dryness of the refrigerant sucked into the compressor 26 is low and the refrigerant discharged from the compressor 26 is in a gas-liquid two-phase state, the state can be eliminated.

  As shown in FIG. 4, when both the first temperature sensor 31 and the second temperature sensor 32 are arranged in the refrigerant circuit 20 between the compressor 26 and the condenser 28, the second temperature sensor 32 is The measurement conditions of the respective temperature sensors are substantially the same without being affected by the temperature of the hot water supply water in the condenser 28, so that the measurement error due to the difference in the measurement conditions between the first temperature sensor 31 and the second temperature sensor 32. The influence of can be eliminated.

  In the above embodiment, the case where heat exchange is performed between the refrigerant and the hot water supply water has been described, but heat exchange may be performed between the refrigerant and the heated fluid other than the hot water supply water. For example, it can also be set as the structure which heat-exchanges between a refrigerant | coolant and heating water by using the heating water used for heating, such as a floor heater and a bathroom drying heater, as a to-be-heated fluid.

  In the above embodiment, the case where heat is exchanged between the refrigerant and one heated fluid (hot water supply water) has been described. However, the heat exchange is performed between the refrigerant and two or more heated fluids. Also good.

  As mentioned above, although the Example of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

4 Heat Pump Heating Device 6 Hot Water Supply Water Circulation Path 8 Hot Water Storage Tank 10 Circulation Pump 12 Mixing Valve 14 Burner Heating Device 16 Bypass Valve 18 Controller 20 Refrigerant Circulation Path 22 Evaporator 24 Fan 26 Compressor 28 Condenser 30 Decompressor 31 First Temperature Sensor 32 Second temperature sensor 34 Water supply path 36 Hot water tank introduction path 38 Hot water tank bypass path 40 Hot water tank outlet path 42 First hot water path 44 Burner heating path 46 Burner bypass path 48 Second hot water path 50 Refrigerant refrigeration cycle 52 Hot water supply water Temperature rise 54 first temperature sensor detected temperature 56 second temperature sensor detected temperature

Claims (6)

A condenser that condenses the refrigerant by exchanging heat between the refrigerant and the fluid to be heated;
A decompressor for decompressing the refrigerant from the condenser;
An evaporator for evaporating the refrigerant from the decompressor;
A blowing means for blowing air to the evaporator;
A compressor that pressurizes the refrigerant from the evaporator and sends it to the condenser;
A first temperature detecting means disposed in the refrigerant flow path between the compressor and the condenser and detecting the temperature of the refrigerant;
Disposed in the refrigerant flow path in the condenser, and includes second temperature detecting means for detecting the temperature of the refrigerant,
If the difference between the detected temperature of the detected temperature and the second temperature detecting means of the first temperature detecting means is less than the predetermined lower limit value, the row physician refrigerant dryness degree increase control for increasing the dryness of the refrigerant sucked into the compressor ,
A heat pump heating device that increases the amount of air blown by the air blowing means in the control for increasing the dryness of the refrigerant . A condenser that condenses the refrigerant by exchanging heat between the refrigerant and the fluid to be heated;
A decompressor for decompressing the refrigerant from the condenser;
An evaporator for evaporating the refrigerant from the decompressor;
A compressor that pressurizes the refrigerant from the evaporator and sends it to the condenser;
A first temperature detecting means disposed in the refrigerant flow path between the compressor and the condenser and detecting the temperature of the refrigerant;
Disposed in the refrigerant flow path in the condenser, and includes second temperature detecting means for detecting the temperature of the refrigerant,
When the difference between the detected temperature of the first temperature detecting means and the detected temperature of the second temperature detecting means is less than a predetermined lower limit value, the refrigerant dryness increase control is performed to increase the dryness of the refrigerant sucked into the compressor,
A heat pump heating device that reduces the rotational speed of a compressor in refrigerant dryness increase control. A condenser that condenses the refrigerant by exchanging heat between the refrigerant and the fluid to be heated;
A decompressor for decompressing the refrigerant from the condenser;
An evaporator for evaporating the refrigerant from the decompressor;
A compressor that pressurizes the refrigerant from the evaporator and sends it to the condenser;
A first temperature detecting means disposed in the refrigerant flow path between the compressor and the condenser and detecting the temperature of the refrigerant;
The refrigerant flow path between the compressor and the condenser is disposed downstream of the first temperature detection means, and includes a second temperature detection means for detecting the temperature of the refrigerant,
When the difference between the detected temperature of the first temperature detecting means and the detected temperature of the second temperature detecting means is less than a predetermined lower limit value, the refrigerant dryness increase control is performed to increase the dryness of the refrigerant sucked into the compressor. Heat pump heating device. It further includes a blowing means for blowing air to the evaporator,
The heat pump heating device according to claim 3, wherein in the refrigerant dryness increase control, the amount of air blown by the blower is increased. The heat pump heating device according to claim 3 or 4, wherein the rotation speed of the compressor is reduced in the refrigerant dryness increase control. A throttle valve provided in the refrigerant flow path,
The heat pump heating device according to any one of claims 1 to 5, wherein the opening degree of the throttle valve is reduced in the refrigerant dryness increase control.

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