JP5081787B2 - Heating system - Google Patents

Description

  The present invention relates to a hybrid heating device including a heat pump and a combustor as a heat source.

  In a hybrid hot water heating apparatus or hot water supply apparatus that includes a heat pump and a combustor as a heat source, the amount of hot water and the hot water temperature are ensured while performing low-cost operation by appropriately using the heat source. For example, in the hybrid hot water supply apparatus described in Patent Document 1, a heat pump capable of low-cost operation is mainly used as a heat source. Water heated by a heat pump water heater is stored in a hot water storage tank and used as needed. Hot water is stored mainly using a heat pump, which is a low-cost heat source, and when the hot water storage tank runs out or the heat pump's heating capacity is insufficient, an instantaneous water heater is used as an auxiliary heat source to supply hot water and hot water temperature. And ensure.

In a hybrid heating apparatus that uses heat storage in a hot water storage tank as a heating terminal, for example, heating water is circulated as a heat medium in a heating circuit including the heating terminal and is heated directly or indirectly by a heat source. The heated heating water circulates through the heating circuit to dissipate heat and is heated again by the heat source. In a heating circuit provided with a high-temperature heating terminal (such as a warm air heater) and a low-temperature heating terminal (such as floor heating) as a heating terminal, when high-temperature heating and low-temperature heating are performed simultaneously, The returning heating water and the heating water returning from the low-temperature heating terminal are mixed and then heated again by the heat source.
JP 2004-125226 A

  However, in order to perform highly efficient heating operation using a heat pump as a heat source, the temperature of the heating water returning from the heating circuit needs to be sufficiently low. When the heating water returning from the heating circuit is so-called medium-temperature water, the efficiency of the heat pump is reduced, and low-cost operation cannot be performed. In a heating circuit provided with a high temperature heating terminal and a low temperature heating terminal as heating terminals, the temperature of the heating water returning from the high temperature heating terminal is higher than the temperature of the heating water returning from the low temperature heating terminal. When the heating water returning from the high temperature heating terminal and the heating water returning from the low temperature heating terminal are mixed as in the prior art, the temperature of the heating water returning from the heating circuit is large because the thermal energy of the heating water returning from the high temperature heating terminal is large. It was getting expensive. As a result, the temperature of the water in the hot water storage tank rises and the intermediate hot water area widens, and the temperature of the water in the lower part of the hot water storage tank cannot be kept sufficiently low, and the water in the lower part of the hot water storage tank is extracted and heated. The efficiency of the heat pump has been reduced.

  Accordingly, the present invention provides a heating circuit including a high-temperature heating terminal and a low-temperature heating terminal, a heat pump, a hot water storage tank that stores water heated by the heat pump, a combustor that heats a heat medium circulating in the heating circuit, Provided is a heating device including a heat exchanger that exchanges heat between water stored in a hot water storage tank and a heat medium circulating in the heating circuit.

In the present invention, a part of the heating circuit branches into a path including the high temperature heating terminal and a path including the low temperature heating terminal, and the path including the high temperature heating terminal is upstream in the flow direction of the heat medium. The combustor and the high temperature heating terminal are connected in series, and in the path including the low temperature heating terminal, the low temperature heating terminal and the heat exchanger are connected in series from the upstream side in the flow direction of the heat medium. The downstream side of the high temperature heating terminal joins the downstream side of the heat exchanger. The heat exchanger is provided outside the hot water storage tank. In the heat exchanger, the heat medium after flowing through the low-temperature heating terminal and the water stored in the hot water storage tank exchange heat. The water exchanged with the heat medium by the heat exchanger is introduced into the central portion of the hot water tank in the height direction.

  If it demonstrates along the flow of the heat medium which circulates through a heating circuit, a heat medium will be shunted into the path | route on the high temperature heating terminal side, and the path | route on the low temperature heating terminal side. The heat medium divided into the route on the high temperature heating terminal side passes through the combustor and then passes through the high temperature heating terminal. After passing through the low-temperature heating terminal, the heat medium divided into the path on the low-temperature heating terminal side passes through a heat exchanger that exchanges heat between the heat medium and water (hot water) stored in a hot water storage tank. The heat medium after passing through the high-temperature heating terminal and the heat medium after passing through the heat exchanger merge, and then are divided again into the route on the high-temperature heating terminal side and the route on the low-temperature heating terminal side, and circulate.

  According to the present invention, the relatively high temperature heating medium returning from the high temperature heating terminal is supplied to the low temperature heating terminal before being supplied to the heat exchanger that exchanges heat between the heating medium and the water stored in the hot water storage tank (hot water). Since it is circulated and supplied to the heat exchanger after the temperature is sufficiently low, the temperature of the water in the hot water storage tank heated by the heat pump can be made sufficiently low, and the efficiency of the heat pump can be kept high. it can.

  ADVANTAGE OF THE INVENTION According to this invention, the efficiency of a heat pump can be improved in the heating apparatus which equips a heat pump and a combustor as a heat source and can implement high temperature heating and low temperature heating. As a result, a heat pump, which is a low-cost heat source, can be effectively used as a heat source, so that the heating device can be operated at a low cost.

The main features of the embodiments described below are listed below.
(Feature 1) The heat medium circulating in the heating circuit is water or antifreeze.
(Feature 2) The refrigerant used in the heat pump unit is R410A.
(Characteristic 3) A first combustor for heating the heat medium circulating in the heating circuit and a second combustor for heating water stored in the hot water storage tank are installed.
(Characteristic 4) The 1st combustor and the 2nd combustor are installed adjacent in the gas heat source unit, and can share a power source, gas piping, etc.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 shows a hybrid hot water supply / room heating device 1 according to this embodiment. The hot water supply / room heating device 1 includes a tank unit 10, a heat pump unit 20, and a gas heat source unit 30.

  The tank unit 10 includes a hot water storage tank 11, a heat exchanger 12 that heats the heat medium, and pumps 121 and 122. Hot water heated by the heat pump unit 20 is stored in the hot water storage tank 11. The hot water storage tank 11 is a hermetic type, and the outside is covered with a heat insulating material. In a state where hot water is stored, temperature stratification is formed inside the hot water storage tank 11, the water temperature at the lower part of the hot water storage tank 11 is low, and the water temperature at the upper part is high. An inlet 118 is provided at the top of the hot water storage tank 11, outlets 111 and 112 and an inlet 113 are provided at the top, and an inlet 116 and an outlet 117 are provided at the bottom. . At the center of the hot water storage tank 11 in the height direction, an outlet 114 and an inlet 115 are provided.

  The heat pump unit 20 is a refrigeration cycle device in which refrigerant circulates in this order through a compressor 21, a radiator 22, an expansion mechanism 23, and an evaporator 24 connected by piping. The water sent from the hot water storage tank 11 to the radiator 22 by the pump 221 is heated by the high-temperature and high-pressure refrigerant discharged from the compressor 21 in the radiator 22. As the expansion mechanism 23, an ejector or an expander may be used in addition to the expansion valve. The evaporator 24 is a fin tube type heat exchanger, and rotates a fan to exchange heat with the outside air.

  The gas heat source unit 30 includes a first combustor 32 that heats a heat medium circulating in the heating circuit, a cistern 33, a high temperature heating terminal (not shown), a low temperature heating terminal (not shown), and a pump 321. , A hot water supply circuit constituted by a second combustor 42 for heating water stored in the hot water storage tank 11, a hot water supply port 44, a water supply port 46, a mixer 48, a reheating heat exchanger 45, and a bath constituted by a pump 421. It is composed of a catch-up circuit. The inlet of the high temperature heating terminal is connected to the high temperature heating forward path 341, and the outlet is connected to the high temperature heating return path 342. The inlet of the low temperature heating terminal is connected to the low temperature heating forward path 351, and the outlet is connected to the low temperature heating return path 352.

  The 1st combustor 32 and the 2nd combustor 42 are combustors which heat water or a heat carrier by burning fuels, such as city gas and LP gas. The first combustor 32 and the second combustor 42 are installed adjacent to each other in the gas heat source unit 30 and can share a gas pipe, a power source, and the like.

  The outlet 331 at the bottom of the cistern 33 is connected to the branching portion 304 via the pump 321 and branched. In the branch part 304, one pipe line is connected to the low temperature heating forward path 351, and the other pipe line is connected to the high temperature heating forward path 341 via the first combustor 32 and the branch part 305. The low temperature heating return path 352 is connected to the heat medium inlet of the heat exchanger 12, and the heat medium outlet of the heat exchanger 12 is connected to the junction 303. The high temperature heating return path 342 is connected to the junction 303. The junction 303 is connected to the inlet 332 at the bottom of the cistern 33. In this embodiment, water is used as the heat medium, and the cistern 33 stores hot water used as heating water in the heating circuit. Hereinafter, in the present embodiment, the case where water is used as the heat medium will be described. However, for example, an antifreeze containing ethylene glycol or the like as a main component can be used instead of water. The systern 33 is provided with a drain outlet 334, and when the water level exceeds the drain outlet 334, the drain is discharged by overflow. Further, a water supply port 335 connected to the water supply port 46 and a water level sensor 333 are provided, and heating water can be supplied based on a detection value of the water level sensor 333.

  The outlet 114 in the center of the hot water storage tank 11 is connected to the inlet of the second combustor 42 via a pump 121 installed in the tank unit 10, and the outlet of the second combustor 42 is connected to the hot water storage tank 11. It is connected to the upper inlet 113. The flow path on the water side of the hot water storage tank 11 of the heat exchanger 12 is connected to the outlet 111 on the inlet side and connected to the inlet 115 via the pump 122 on the outlet side.

  The water inlet 46 and the outlet 112 at the top of the hot water storage tank 11 are connected by a junction 401, and the junction 401 is connected to the hot water inlet 44. A pipe that connects the water inlet 46 and the junction 401 is provided with a mixer 48 that adjusts the mixing ratio of the hot water and the hot water in the hot water storage tank 11 according to the required temperature of the hot water supply.

  The branching part 305 is connected to the inlet of the reheating heat exchanger 45, and the outlet of the reheating heat exchanger 45 is provided in a pipe line connecting the junction part 303 and the introduction port 332 of the cistern 33. Connected to the junction 306. The reheating heat exchanger has a double-pipe structure, the heat medium passage is on the inside, and the passage of hot water stored in the bathtub is on the outside. The pump 421 circulates hot water stored in the bathtub.

  Next, hot water storage and hot water supply operations of the present embodiment will be described. The bottom of the hot water storage tank 11 is supplied with clean water from an inlet 116 connected to the clean water supply. The outlet 117 at the bottom of the hot water storage tank 11 is connected to the radiator 22 of the heat pump unit 20, and low-temperature water at the bottom of the hot water storage tank 11 is supplied by the pump 221 to exchange heat with the refrigerant in the radiator 22. In the present embodiment, the capacity of the heat pump unit 20 is 6.0 kW. R410A is used as the refrigerant, and the temperature of the hot water at the outlet of the radiator 22 is about 50 to 60 ° C. The heat pump unit 20 is controlled by a general refrigeration cycle apparatus control method. For example, it can be controlled based on the discharge temperature of the compressor 21, the outside air temperature, and the inlet temperature of the radiator 22 of water flowing in from the hot water storage tank 11.

  The hot water heated by the heat pump unit 20 returns from the inlet 118 to the top of the hot water storage tank 11. The lower part of the water stored in the hot water storage tank 11 has a low temperature, and the temperature gradually increases toward the upper part. In the present embodiment, the hot water temperature in the upper part of the hot water storage tank 11 is about 50 to 60 ° C.

  If the capacity of the heat pump unit 20 is insufficient when the hot water heater 1 is started or when the hot water storage tank 11 runs out, the hot water in the hot water storage tank 11 is further increased using a hot water combustion circuit that passes through the second combustor 42. Heat. In the hot water supply combustion circuit, hot water having an intermediate temperature is extracted from the outlet 114, heated by the second combustor 42, and returned from the inlet 113 to the upper part of the hot water storage tank 11. The hot water in the hot water storage tank 11 is circulated through the hot water supply combustion circuit by the pump 121 and heated by the second combustor 42.

  As hot water supply water, hot hot water at the upper part of the hot water storage tank 11 from the outlet 112 is appropriately mixed with hot water supplied from the water supply port 46 and supplied to the hot water supply port 44. The mixer 48 adjusts the mixing ratio between the hot water and the hot water at the upper part of the hot water storage tank 11 based on the required temperature of the hot water supply, the temperature of the hot water at the upper part of the hot water storage tank 11, the temperature of the fresh water. When there is a demand for hot water for hot water higher than the hot water in the upper part of the hot water storage tank 11, the hot water temperature in the upper part of the hot water storage tank 11 is rapidly increased by the hot water supply combustion circuit using the second combustor 42. be able to.

  Next, the heating operation of the present embodiment will be described. In the tank unit 10, a hot medium heating circuit for extracting hot hot water at the upper part of the hot water storage tank 11 from the outlet 111, passing the heat exchanger 12, and returning the hot water from the inlet 115 to the middle hot water region in the central part of the hot water storage tank 11. Thus, the heating water used as the heat medium and the hot water in the hot water storage tank 11 are heat-exchanged. The water for heating is heated by the hot water in the hot water storage tank 11 by circulating the hot water in the hot water storage tank 11 through the heat medium heating circuit by the pump 121.

  The heating water heated by the heat exchanger 12 merges with the heating water flowing through the high-temperature heating return path 342 at the junction 303. Heating water that has joined at the junction 303 is introduced into the systern 33 from the inlet 332. Heating water is pumped out by the pump 321 from the outlet 331 at the bottom of the cistern 33 and is divided in the branching section 304. One of the diverted heating water flows into the low temperature heating forward path 351. The other passes through the first combustor 32 and then flows into the high temperature heating forward path 341 via the branching portion 305. Heating water that has passed through the low-temperature heating terminal flows through the low-temperature heating return path 352, flows into the heat exchanger 12, and is heated again by the hot water in the upper part of the hot water storage tank 11. The heating water that has passed through the high-temperature heating terminal flows through the high-temperature heating return path 342 and merges with the heating water heated by the heat exchanger 12 at the junction 303.

  If the heating water (heating water after passing through the first combustor 32) supplied from the branching section 305 to the high temperature heating forward path 341 is introduced into the reheating heat exchanger 45, it is possible to retreat the bath. . In the bath reheating circuit, the hot water stored in the bathtub by the pump 421 is circulated through the outer pipe of the reheating heat exchanger 45 to exchange heat with the heating water passing through the inner pipe of the reheating heat exchanger 45. By doing that, we will catch up. The heating water used for reheating is returned from the junction 306 to the bottom of the cistern 33 in the same manner as the heating water in the high-temperature heating return path 342.

  In the present embodiment, the temperature of the heating water heated by the heat exchanger 12 is 40 to 60 ° C., and the temperature of the heating water in the high-temperature heating return path 342 is about 60 to 70 ° C. The temperature of the heating water is about 60 ° C. Since the temperature of the heating water in the high-temperature heating forward path 341 needs to be about 80 ° C., the first combustor 32 is heated to about 80 ° C. When the temperature of the heating water in the low-temperature heating forward path 351 is about 60 ° C., the temperature of the heating water in the low-temperature heating return path 352 is 30 to 50 ° C. at the inlet of the heat exchanger 12.

  According to this embodiment, since the heating water in the high temperature heating return path always passes through the low temperature heating terminal and then returns to the heat exchanger, the thermal energy of the heating water in the high temperature heating return path is effectively used in the low temperature heating terminal. Is done. Only the water for heating, which has been sufficiently heated by the low-temperature heating terminal, is returned to the heat exchanger. Thereby, in the heat exchanger, a temperature difference between the water for heating and the hot water from the hot water storage tank is ensured, and the heat exchange efficiency is improved, so that the temperature of the water returning to the hot water storage tank can be sufficiently lowered. Since the water whose temperature has been sufficiently lowered is returned to the center of the hot water storage tank, the water temperature at the bottom of the hot water storage tank can be kept low. Thus, the temperature of the water sent from the bottom of the hot water storage tank to the heat pump unit can be kept low, so that the heat pump unit can be operated with high efficiency. In a hybrid water heater / heater equipped with a heat pump and a combustor as heat sources, a heat pump that is a low-cost heat source can be used effectively, so that low-cost operation can be realized.

  Further, in this embodiment, the heating water in the high temperature heating return path and the heating water heated by the heat exchanger are merged so that the temperature of the heating water becomes a temperature required for the heating water in the low temperature heating outbound path. Can be adjusted.

  Further, according to the hot water supply and heating apparatus of the present embodiment, the inlet temperature of water heated by the heat pump unit can be lowered, so that the boiling temperature can be raised only to about 50 to 60 ° C. Even if the system refrigerant is used, a temperature difference between the heating water and the refrigerant temperature can be secured, and the heat pump unit can be used effectively to perform boiling.

  Moreover, in the hot water supply and heating apparatus of the present embodiment, since the first combustor for heating the heating water and the second combustor for heating the water in the hot water storage tank are provided separately, the maximum temperature of the hot water stored in the hot water storage tank is Even if it is about 50-60 degreeC, it can respond to hot water supply and high temperature heating of high temperature (for example, 80 degreeC) rapidly. Since the temperature of the hot water stored in the hot water storage tank may be low, heat loss in the hot water storage tank (for example, heat dissipation due to a temperature difference from the outside air) can be reduced. In addition, particularly efficient operation can be realized when low temperature heating is used regularly and high temperature heating is used temporarily.

  In addition, although the present Example demonstrated the case of the hot water supply and heating apparatus, this invention is applicable also to the heating only apparatus which is not provided with a hot water supply circuit.

In this embodiment, the case where R410A is used as the refrigerant has been described. However, if the inlet temperature of the water heated by the heat pump unit is lowered, the efficiency of the heat pump unit is improved in addition to the CO ₂ refrigerant and the like. The same applies to the other refrigerant. This contributes to improving the efficiency of the heat pump unit and enables low-cost operation of the hybrid hot-water heater / heater.

  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.

The figure explaining the hot-water supply heating apparatus of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water supply and heating apparatus 10 Tank unit 11 Hot water storage tank 12 Heat exchanger 20 Heat pump unit 21 Compressor 22 Radiator 23 Expansion mechanism 24 Evaporator 30 Gas heat source unit 32 1st combustor 33 Systurn 42 2nd combustor 44 Hot water supply port 45 Heat exchanger 46 for watering Water inlet 48 Mixer 111, 112, 114, 117 Hot water tank outlet 113, 115, 116, 118 Hot water tank inlet 121, 122, 221, 321, 421 Pump 303, 306, 401 304, 305 Branch 331 Systurn outlet 332 Systurn inlet 333 Water level sensor 334 Discharge port 335 Water supply port 341 High temperature heating return path 342 High temperature heating return path 351 Low temperature heating return path 352 Low temperature heating return path

Claims (1)

A heating circuit comprising a high temperature heating terminal and a low temperature heating terminal;
A heat pump,
A hot water storage tank for storing water heated by a heat pump;
A combustor for heating a heat medium circulating in the heating circuit;
A heating device provided outside the hot water storage tank , comprising a heat exchanger for exchanging heat between water stored in the hot water storage tank and a heat medium circulating in the heating circuit;
The heating circuit is branched in part into a path including the high temperature heating terminal and a path including the low temperature heating terminal,
In the path including the high temperature heating terminal, the combustor and the high temperature heating terminal are connected in series from the upstream side in the flow direction of the heat medium, and the path including the low temperature heating terminal is the flow of the heat medium. The low temperature heating terminal and the heat exchanger are connected in series from the upstream side of the direction,
The downstream side of the high-temperature heating terminal is joined to the downstream side of the heat exchanger ,
In the heat exchanger, the heat medium after flowing through the low-temperature heating terminal and water stored in the hot water storage tank are heat-exchanged,
The heating medium and the heat exchange water in the heat exchanger, the heating device according to claim Rukoto is introduced into the central portion in the height direction of the hot water storage tank.

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