JP2012225596A - Heat pump system for heating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a COP of a heat pump unit for heating relatively high, without wasting thermal energy and resources.SOLUTION: A heat pump system for heating includes: a medium-temperature water circulation path 11 and a medium-temperature water circulation device 10 that circulate a medium-temperature water collected from a relatively lower portion of a hot-water storage tank 5 to return to the hot-water storage tank 5; a heat radiation device 12 that is positioned in the middle of the medium-temperature water circulation path 11 and radiates heat of the medium-temperature water; a heat exchanging ventilator 15 that introduces outside air having a lower temperature than an indoor temperature; and a controlling device 14 that controls the heat pump unit, a water circulation device 7, a hot-water circulation device 8, and the medium-temperature water circulation device 10. The heat radiation device 12 radiates heat to the outside air introduced by the heat exchanging ventilator 15 to cool a temperature of the medium-temperature water to a predetermined temperature or lower, and thereafter operates the water circulation device 7 to heat that cooled water with the heat pump unit.

Description

  The present invention relates to a home heating system using heat pump technology.

  Generally, in a heat pump, if the refrigeration cycle is configured in a relatively low temperature range of the temperature range that can be heated with the refrigerant used, the energy efficiency (COP) is high, and if operated in a relatively high temperature range, the COP is low. A hot water supply heat pump does not pose a big problem because hot water of about 65 ° C. is produced from tap water at a relatively low temperature (10 to 25 ° C.), but it becomes a problem in a heating heat pump that circulates and uses hot water. This is because many heaters have a relatively small temperature difference at the entrance and exit, and thus operate in a relatively high temperature range.

  In order to solve this problem, in Patent Document 1, a part of tap water is introduced into a heat exchanger installed at the lower part of the hot water tank to lower the water temperature at the lower part, so that the COP is not lowered. Moreover, since warmed tap water is used for adjusting the tapping temperature, heat energy is not wasted.

JP 2008-39305 A

  If the above technology is used in an environment where the amount of hot water used is relatively small, such as in general European homes, it is necessary to achieve both the effect of lowering the water temperature at the bottom of the hot water tank and the effect of adjusting the hot water temperature. There is a problem that it can only operate under limited conditions. Therefore, under actual use conditions, there is a problem that the water in the lower part of the hot water tank cannot be sufficiently cooled and the COP is reduced, or a part of the cooling tap water and heat energy is wasted. I think that the. In the latter case, even if the nominal COP is improved, the same amount of heat as the COP improvement effect is actually wasted, so it can be said that there is no substantial effect.

  An object of the present invention is to keep the COP of a heating heat pump relatively high without wasting heat energy and resources.

  In the heat pump system for heating according to the present invention, a heat pump unit including a condenser, an expansion valve, an evaporator, and a compressor, a hot water storage tank that stores hot water generated by receiving heat from the condenser, and the hot water storage tank Water supply means for supplying tap water, water circulation means for circulating water between the hot water storage tank and the condenser, heating terminal equipment for releasing heat generated by the heat pump unit indoors, and the heating terminal equipment, A hot water circulation means for circulating hot water between the hot water storage tank, an intermediate hot water circulation path and an intermediate hot water circulation means for circulating the intermediate hot water collected from a relatively lower position of the hot water tank and returning the hot water to the hot water tank; A heat dissipating means for dissipating the heat of the medium hot water located in the middle of the hot water circulation path, a ventilating means for introducing outside air having a temperature lower than the indoor air temperature, the heat pump unit and the water circulation And a control means for controlling the hot water circulating means and the intermediate warm water circulating means, and the heat radiating means radiates heat to the outside air introduced by the ventilation means to keep the temperature of the intermediate warm water below a predetermined temperature. Then, the water circulating means is operated after being cooled to the temperature and heated by the heat pump unit.

  As a result, the COP of the heating heat pump unit can be kept relatively high without wasting heat energy and water resources.

Configuration diagram of a heat pump system for heating in the first embodiment The block diagram of the heat pump system for heating in 2nd Embodiment The block diagram of the heat exchange ventilation apparatus in Embodiment 2 of this invention The block diagram of the heat pump system for heating in 3rd Embodiment The block diagram of the heat pump system for heating in 4th Embodiment Configuration diagram of a conventional heat pump system

  A first invention includes a heat pump unit including a condenser, an expansion valve, an evaporator, and a compressor, a hot water storage tank that stores hot water generated by receiving heat from the condenser, and tap water in the hot water storage tank. Water supply means to supply; water circulation means for circulating water between the hot water storage tank and the condenser; heating terminal equipment for releasing heat generated by the heat pump unit indoors; the heating terminal equipment and the hot water storage tank A hot water circulating means for circulating hot water between the hot water tank, an intermediate hot water circulation path and an intermediate hot water circulating means for circulating the hot water collected from a relatively lower side of the hot water tank and returning it to the hot water tank, and the intermediate hot water circulation path A heat dissipating means for dissipating the heat of the intermediate temperature water, a ventilating means for introducing outside air having a temperature lower than the indoor temperature, the heat pump unit, the water circulation means, the hot water circulation means, Control means for controlling the intermediate temperature water circulation means, and the heat dissipation means radiates heat to the outside air introduced by the ventilation means to cool the water temperature of the intermediate temperature water below a predetermined temperature, and then the water circulation It is a heat pump system for heating in which the means is operated and heated by the heat pump unit. Since indoor air is always ventilated by a predetermined amount or more, the intermediate temperature water can be cooled and the COP can be kept at a relatively high value by releasing heat to the introduced air. In addition, since heat energy is used to warm the introduced air, it can be used for indoor air conditioning by using a heat cascade.

  In particular, the second aspect of the present invention is the heating heat pump system according to the first aspect of the present invention, further comprising water temperature detection means for detecting the temperature of the intermediate temperature water, and the control means is configured to control the temperature of the intermediate temperature water from tap water by the water temperature detection means. If it is detected that the temperature is within a predetermined temperature range that is higher than the temperature of the warm water, the medium temperature water circulating means is operated to dissipate the medium temperature water and cool the water temperature below a predetermined temperature, It is operated and heated by a heat pump unit.

  The third invention is particularly characterized in that, in the heat pump system for heating according to the first or second invention, the heat pump unit is characterized in that the refrigerant is CO2.

  The fourth invention, in particular, in the heat pump system for heating according to any one of the first to third inventions, has an outdoor air temperature detecting means for detecting the outdoor air temperature and transmitting the outdoor air temperature to the control means. When the outdoor air temperature detected by the outdoor air temperature detecting means is lower than the temperature of the intermediate temperature water, the intermediate temperature water circulating means is operated.

  The fifth aspect of the invention is particularly the heating heat pump system according to any one of the first to third aspects of the invention, wherein the ventilation means is a heat exchange ventilator, and the heat dissipation means is more than the heat exchanger of the heat exchange air apparatus. It is a water / air heat exchanger provided on the indoor side, and has an introduction air temperature detection means for detecting the indoor introduction air temperature after heat exchange and transmitting the introduction air temperature to the control means. The control means is controlled by the introduction air temperature detection means. When the detected introduction air temperature is lower than the temperature of the medium temperature water, the medium temperature water circulation means is operated.

  In a sixth aspect of the present invention, in particular, in the heating heat pump system according to any one of the first to third aspects of the invention, the ventilation means is a heat exchange ventilator, and the heat dissipation means is provided in the heat exchanger of the heat exchange air apparatus. A temperature gradient and an intermediate temperature water temperature gradient are provided integrally with the heat exchanger so as to be parallel to each other, and has an outdoor air temperature detection means for detecting an outdoor air temperature, and the control means has the outdoor air temperature from the temperature of the intermediate temperature water. If the temperature is too low, the medium warm water circulation means is operated.

  In a seventh aspect of the invention, in particular, in the heat pump system for heating according to any one of the first to third aspects of the invention, the ventilation means is a heat exchange ventilator, and the heat dissipation means is more than the heat exchanger of the heat exchange air apparatus. Two water / air heat exchangers provided separately on the outdoor side and the indoor side, and having an introduction air temperature detection means for detecting the indoor introduction air temperature after heat exchange, and the control means is based on the introduction air temperature The medium temperature water circulation means is activated.

  According to an eighth aspect of the invention, in particular, in the heating heat pump system according to any one of the first to seventh aspects of the invention, the control means is configured to circulate medium hot water so that the temperature of the indoor introduction air of the ventilation means is equal to or higher than the indoor air temperature The circulation flow rate of the means is controlled.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a heating heat pump system according to a first embodiment of the present invention.

  In FIG. 1, a condenser 1, an expansion valve 2, an evaporator 3 and a compressor 4 constitute a heat pump unit. The hot water tank 5 temporarily stores low-temperature water introduced by water supply means 6 such as water. The water circulating means 7 heats the low-temperature water by exchanging heat with the condenser 1, and the generated high-temperature water is stored from the upper part of the hot water tank 5. The hot water circulation means 8 introduces the hot water in the upper part of the hot water tank 5 into the heating terminal device 9 to supply heat. The warm water becomes medium warm water with a slight drop in temperature, is returned to the hot water storage tank 5, and is mainly accumulated in the lower part because the specific gravity is relatively large. The intermediate temperature water circulating means 10 causes the intermediate temperature water to flow through the intermediate temperature water circulation path 11, dissipates heat by the heat radiating means 12, and then returns to the lower part of the hot water tank 5 again. A water temperature detecting means 13 for detecting the temperature of the stored water is provided in the lower part of the hot water tank 5. The control means 14 controls the operation of the heat pump unit, the water circulation means 7, the hot water circulation means 8, and the intermediate warm water circulation means 10. The heat dissipating means 12 is installed in a ventilation channel on the indoor side of the heat exchanger 16 of the heat exchanging ventilator 15 which is one of the ventilating means. The introduction air temperature detection means 17 is installed between the heat exchanger 16 and the heat dissipation means 12. The temperature information detected by the water temperature detection means 13 and the introduction air temperature detection means 17 is input to the control means 14. Some of the hot water in the hot water storage tank 5 is discharged from a hot water outlet 18 such as a shower or a currant, but in the embodiment of the present invention, heat consumption by the heating terminal device 9 is relatively larger than that from the hot water outlet 18. Therefore, it is assumed that the hot water circulation is frequently used.

  As the working medium of the heat pump unit, various refrigerants such as R22, R410A, R407C, and R744 (CO2) are used. In any of the refrigerants in the present invention, the effect of improving COP as compared with a single heat pump unit is achieved. is there. In particular, in the case of CO2 refrigerant, the COP value reacts more sensitively to the outlet temperature of the condenser than other refrigerants, so that a greater COP improvement effect can be expected.

  As the heating terminal device 9, a heating radiator or a floor heating unit is assumed. The heat dissipating means 12 is for exchanging heat between water and introduced air, and a cross-fin heat exchanger is considered as a general form.

  The heat exchange ventilator 15 is for exchanging heat between dirty indoor air and fresh outside air. The heat exchange efficiency is generally about 70%. For example, when the indoor air temperature is 20 ° C. and the outdoor air temperature is 0 ° C., the temperature of the indoor introduction air after the heat exchange is expected to be 14 ° C. according to the equation (1).

(20 ° C.−0 ° C.) × 70% + 0 ° C. = 14 ° C. Formula (1)
Therefore, although the heat exchange ventilator 15 performs heat exchange, the air introduced in the severe cold season is lower than the room temperature, and using the heat exchange ventilator 15 alone may give a cold feeling to an indoor person.

  About the characteristic part of the heat pump system for heating comprised as mentioned above, the effect | action is demonstrated below.

  Usually, the temperature of hot water stored in the hot water tank 5 is 65 ° C. or higher in order to suppress the growth of sanitary harmful bacteria. Further, in the heating terminal device 9, the temperature difference between the entrance and the exit is controlled to about 5 ° C. in order to maintain comfort. Even if heat exchange with the heating terminal device 9 is devised, the return water by the hot water circulation means 8 is usually about 35 ° C. in many cases. In the present embodiment, an example will be described in which the return water is 35 ° C., and therefore the temperature of the medium-temperature water accumulated in the lower part of the hot water tank 5 is 35 ° C. In the following example, the room temperature is 20 ° C., the outdoor temperature is 0 ° C., and the heat exchange efficiency of the heat exchange ventilator 15 is 70%.

  The water temperature detecting means 13 and the sampling port of the intermediate hot water circulation path 11 are provided at substantially the same depth in the hot water tank 5. When the following two conditions are met, the control means 14 activates the intermediate temperature water circulation means 10 to cool the intermediate temperature water.

Condition 1: The presence of medium-temperature water is detected in the hot water tank 5 by the water temperature detection means 13 Condition 2: The introduction temperature detected by the introduction temperature detection means 17 is lower than the temperature of the medium-temperature water The above two conditions are satisfied Then, the control means 14 operates the intermediate warm water circulating means 10 to cool the intermediate warm water by the heat radiating means 12 and then introduces it into the bottom of the hot water tank 5. Since the water after cooling is lower than 35 ° C., it mainly accumulates at the bottom. The operation of the medium temperature water circulating means 10 is continued until the water temperature detecting means 13 detects that the water temperature at the installation depth is lower than 35 ° C. After the medium temperature water circulating means 10 is stopped, the control means 14 operates the water circulating means 7 and the heat pump unit to boil up the cooled water to 65 ° C. The COP value is higher than boiling from medium temperature water at 35 ° C.

  As described above, a heat pump unit including a condenser, an expansion valve, an evaporator, and a compressor, a hot water tank that stores hot water generated by receiving heat from the condenser, and tap water is supplied to the hot water tank. Water supply means, water circulation means for circulating water between the hot water storage tank and the condenser, heating terminal equipment for releasing heat generated by the heat pump unit indoors, the heating terminal equipment and the hot water storage tank, A hot water circulation means for circulating hot water between the hot water tank, an intermediate hot water circulation path and medium hot water circulation means for circulating medium hot water collected from a relatively lower side of the hot water tank and returning it to the hot water tank, and the intermediate hot water circulation path A heat dissipating means for dissipating the heat of intermediate temperature water located in the middle, a ventilating means for introducing outside air having a temperature lower than the indoor temperature, the heat pump unit, the water circulation means, the hot water circulation means, Control means for controlling the intermediate temperature water circulation means, and the heat dissipation means radiates heat to the outside air introduced by the ventilation means to cool the water temperature of the intermediate temperature water below a predetermined temperature, and then the water circulation By operating the means and heating the heat pump unit, the COP of the heating heat pump unit can be kept relatively high without wasting heat energy and resources.

Further, as described above, it has a water temperature detecting means for detecting the temperature of the intermediate temperature water, and the control means is a predetermined temperature range in which the temperature of the intermediate temperature water is higher than the tap water and lower than the temperature of the hot water by the water temperature detection means. When the medium temperature water is detected, the medium temperature water circulating means is operated to dissipate the medium temperature water, the water temperature is cooled to a predetermined temperature or lower, and then the water circulation means is operated and heated by the heat pump unit. It is possible to operate the intermediate temperature water circulating means 10 only when the temperature is present, and energy consumption for the intermediate temperature water circulation can be minimized.

  In addition, since the temperature of medium temperature water changes with the specifications of the heating terminal device 9, the control means 14 is comprised so that the temperature setting of medium temperature water can be changed according to the heating terminal device combined at the time of installation.

  On the other hand, in the heat exchange ventilator 15, the temperature of air introduced from the heat exchanger 16 to the indoor side is 14 ° C. in calculation, but is heated by passing through the heat dissipating means 12. In the case of a single heat exchange ventilator, the indoor air introduced in winter was lower than the room air temperature, and there was a drawback of giving the occupants a cool feeling near the ventilation inlet, but the heat pump unit for heating as in this embodiment It is possible to solve the problem of cold feeling by systematizing.

  As described above, the ventilation means is a heat exchange ventilator, and the heat radiating means is a water / air heat exchanger provided on the indoor side of the heat exchanger of the heat exchange air apparatus. Introducing air temperature detecting means for detecting the air temperature and transmitting the introducing air temperature to the control unit, the control means activates the intermediate temperature water circulating means when the introduced air temperature detected by the introducing air temperature detecting means is lower than the temperature of the intermediate temperature water. Therefore, the COP improvement effect can be exhibited at the same time while preventing the cool feeling due to ventilation.

  Further, by using the heat pump system of the present invention, it is possible to heat not only the heating terminal device 9 but also the indoor introduction air of the heat exchange ventilator 15 partially. For example, about 70 to 90% of the required heating output can be covered by the heating terminal device 9, and the remaining 10 to 30% can be performed by the indoor introduction air. In that case, the temperature of indoor introduction air becomes higher than 20 degreeC of room temperature. When the ventilation inlet is installed at a low position in the room, a feeling of warmth can be given to the feet and comfort can be improved. In addition, since the output of the heating terminal device 9 can be reduced as compared with the case of heating only by the heating terminal device 9, it is possible to reduce the cooling means of the medium-temperature water, and as a result, the heat dissipation means 12 and the medium The hot water circulation means 10 can be reduced in size.

    As described above, the control means exerts a COP improvement effect with a relatively small configuration by controlling the circulation flow rate of the medium-temperature water circulation means so that the temperature of the indoor introduction air of the ventilation means becomes equal to or higher than the indoor air temperature. It is possible, and the warming effect by warming indoor introduction air can be exhibited.

(Embodiment 2)
FIG. 2 is a configuration diagram of a heat pump system for heating according to the second embodiment of the present invention. Since the configuration and operation of the present embodiment have many parts in common with the first embodiment, only different parts will be described below.

  As shown in FIG. 3, the heat dissipating means 12 of the present embodiment is integrated with the heat exchanger 16 of the heat exchanging ventilator 15, and the temperature gradient of the air in the heat exchanger and the medium hot water circulation path 11 It is provided so that the temperature gradient of water is in parallel. The colored portion in FIG. 3 represents a high temperature fluid. An arrow indicates air introduced into the heat exchanger.

  In the present embodiment, the outdoor air temperature detection means 19 is provided in the outside air introduction part of the heat exchange ventilator 15. When the following two conditions are met, the control means 14 activates the intermediate temperature water circulation means 10 to cool the intermediate temperature water.

Condition 1: The presence of medium temperature water is detected in the hot water tank 5 by the water temperature detection means 13 Condition 2: The outdoor temperature detected by the outdoor temperature detection means 19 is lower than the temperature of the medium temperature water Outside the heat exchanger 16 Compared to the first embodiment in which the heat dissipating means 12 is provided, an installation space for the heat dissipating means 12 is not required, and the entire structure can be reduced in size. Moreover, in the low temperature part on the left side of FIG. 3, since the low temperature outside air and the intermediate warm water circulation path 11 are in contact with each other, the effect of lowering the intermediate warm water is great. On the other hand, since a part of the heat of the medium-temperature water is thrown away outdoors by heat exchange ventilation, it may be wasted in terms of heat energy.

  As described above, the ventilation means is a heat exchange ventilator, and the heat dissipation means is integrated with the heat exchanger so that the temperature gradient in the heat exchanger of the heat exchange air device and the temperature gradient of the intermediate temperature water are in parallel. The outdoor air temperature detecting means for detecting the outdoor air temperature, and the control means is a small system by operating the intermediate warm water circulation means when the outdoor air temperature is lower than the temperature of the intermediate warm water, and It has the feature that it is easy to cool medium temperature water.

(Embodiment 3)
FIG. 4 is a configuration diagram of a heat pump system for heating according to the third embodiment of the present invention. Since the configuration and operation of the present embodiment have many parts in common with the first embodiment, only different parts will be described below.

  As shown in FIG. 4, the heat dissipating means 12 of the present embodiment is divided into two parts, one of which is 12b on the indoor side from the heat exchanger 16 of the heat exchanging ventilator 15 as in the first embodiment. One 12 a is provided in each air flow path on the outdoor side of the heat exchanger 16.

  In the present embodiment, the introduction temperature detecting means 17 is provided on the indoor side of the heat exchanger 16. The operating conditions of the medium temperature water circulating means 10 are the same as those in the first embodiment.

  By providing one of the heat dissipating means 12a on the outdoor side of the heat exchanger, it is expected that the effect of improving the COP value is greater because the effect of cooling the medium-temperature water is greater than that of the first embodiment. Moreover, cooling is possible even in the case of an outside air temperature higher than that of the first embodiment. On the other hand, since a part of the heat of the medium-temperature water is thrown away outdoors by heat exchange ventilation, it may be wasted in terms of heat energy.

  As described above, the ventilation means is a heat exchange ventilator, and the heat dissipation means is two water / air heat exchangers that are provided on the outdoor side and the indoor side separately from the heat exchanger of the heat exchange air device. There is an introduction air temperature detection means for detecting the indoor introduction air temperature after heat exchange, and the control means operates the intermediate warm water circulation means based on the introduction air temperature, so that it is easy to cool the intermediate temperature water.

(Embodiment 4)
FIG. 5 is a configuration diagram of a heat pump system for heating according to the fourth embodiment of the present invention. Since the configuration and operation of the present embodiment have many parts in common with the first embodiment, only different parts will be described below.

  The ventilation means 20 of the present embodiment performs ventilation without heat exchange. The heat dissipating means 12 is provided in the air channel on the indoor side of the ventilation means 20.

  In the present embodiment, the outdoor air temperature detection means 19 is provided on the outdoor side of the heat dissipation means 12. When the following two conditions are met, the control means 14 activates the intermediate temperature water circulation means 10 to cool the intermediate temperature water.

Condition 1: The presence of medium temperature water is detected in the hot water tank 5 by the water temperature detection means 13 Condition 2: The outdoor temperature detected by the outdoor temperature detection means 19 is lower than the temperature of the medium temperature water. Since the medium-temperature water can be cooled at the lowest outdoor air temperature as compared with the first to third embodiments, the effect of improving the COP value can be expected to be greater. Moreover, compared with the case where the ventilation means 20 is not combined with a heat pump unit, there exists the feature that the effect of improving the temperature of indoor introduction air is large. On the other hand, since the exhaust is performed somewhere indoors, the amount of heat released from the house is the same as when not combined.

  As described above, the outdoor air temperature detecting means for detecting the outdoor air temperature and transmitting the outdoor air temperature to the control unit is provided, and the control means is used when the outdoor air temperature detected by the outdoor air temperature detecting means is lower than the temperature of the medium temperature water. By operating the hot water circulation means, the COP improvement effect can be exhibited with a relatively small configuration, and the warm feeling effect by warming the indoor introduction air can be exhibited.

  As described above, the heating heat pump system according to the present invention can keep the COP of the heating heat pump unit relatively high without wasting heat energy and resources, so that food processing, brewing, chemical industry, etc. It can also be applied to heating applications for constant bath temperature in a constant temperature (reaction) bath in various industries.

DESCRIPTION OF SYMBOLS 1 Condenser 2 Expansion valve 3 Evaporator 4 Compressor 5 Hot water storage tank 6 Water supply means 7 Water circulation means 8 Warm water circulation means 9 Heating terminal equipment 10 Medium temperature water circulation means 11 Medium temperature water circulation path 12 Heat radiation means 13 Water temperature detection means 14 Control means 15 Heat exchange ventilator 16 Heat exchanger 17 Introduction temperature detection means 18 Hot water outlet 19 Outdoor temperature detection means

Claims (8)

A heat pump unit comprising a condenser, an expansion valve, an evaporator and a compressor;
A hot water tank for storing hot water generated by receiving heat from the condenser;
Water supply means for supplying tap water to the hot water tank;
Water circulation means for circulating water between the hot water tank and the condenser;
A heating terminal device that releases heat generated by the heat pump unit indoors;
Hot water circulation means for circulating hot water between the heating terminal device and the hot water storage tank;
A medium-temperature water circulation path and medium-temperature water circulation means for circulating medium-temperature water collected from a relatively lower side of the hot-water tank and returning it to the hot-water tank;
A heat dissipating means for dissipating heat of the medium temperature water located in the middle of the medium temperature water circulation path;
Ventilation means to introduce outside air that is cooler than the indoor temperature;
A control means for controlling the heat pump unit, the water circulation means, the hot water circulation means and the intermediate warm water circulation means,
The heat dissipating means radiates heat to the outside air introduced by the ventilating means, cools the water temperature of the medium temperature water below a predetermined temperature, and then operates the water circulation means to heat by the heat pump unit. Heat pump system. When having a water temperature detection means for detecting the temperature of the medium temperature water, and the control means detects that the temperature of the medium temperature water is higher than the tap water and lower than the temperature of the warm water by the water temperature detection means 2. A heat pump for heating according to claim 1, wherein the medium temperature water circulating means is operated to radiate the medium temperature water to cool the water temperature to a predetermined temperature or less, and then the water circulation means is operated to heat by the heat pump unit. system. The heat pump system for heating according to claim 1 or 2, characterized in that the refrigerant of the heat pump unit is CO2. There is an outdoor air temperature detecting means for detecting the outdoor air temperature and transmitting the outdoor air temperature to the control means, and the control means operates the medium hot water circulation means when the outdoor air temperature detected by the outdoor air temperature detecting means is lower than the temperature of the intermediate temperature water. The heat pump system for heating according to any one of claims 1 to 3, wherein the heat pump system is used. The ventilation means is a heat exchange ventilator, and the heat dissipation means is a water / air heat exchanger provided on the indoor side of the heat exchanger of the heat exchange air apparatus, and detects and controls the indoor introduction temperature after heat exchange. An introduction air temperature detection means for transmitting the introduction air temperature to the means, and the control means operates the intermediate hot water circulation means when the introduction air temperature detected by the introduction air temperature detection means is lower than the temperature of the intermediate temperature water. The heat pump system for heating according to any one of 1 to 3. The ventilation means is a heat exchange ventilator, and the heat radiating means is provided integrally with the heat exchanger so that the temperature gradient in the heat exchanger of the heat exchange air device and the temperature gradient of the medium temperature water are arranged in parallel. The outdoor air temperature detecting means for detecting the air temperature is provided, and the control means operates the intermediate hot water circulating means when the outdoor air temperature is lower than the temperature of the intermediate temperature water. Heat pump system for heating. The ventilation means is a heat exchange ventilator, and the heat radiating means is two water / air heat exchangers provided separately on the outdoor side and indoor side of the heat exchanger of the heat exchange air device, and after heat exchange The heating heat pump system according to any one of claims 1 to 3, further comprising an introduction air temperature detecting means for detecting the indoor introduction air temperature, wherein the control means operates the medium hot water circulation means based on the introduction air temperature. . The heat pump for heating according to any one of claims 1 to 7, wherein the control means controls the circulation flow rate of the medium-temperature water circulation means so that the temperature of the indoor introduction air of the ventilation means becomes equal to or higher than the indoor air temperature. system.