JP5217624B2 - Heating system - Google Patents

Description

  The present invention relates to a heating system that heats a heat medium of a heat transfer circuit provided with a use side heat exchanger by a refrigerant of a refrigerant circuit.

  2. Description of the Related Art Conventionally, there is known a heating system that heats a heat medium of a heat transfer circuit provided with a use side heat exchanger by a refrigerant of a refrigerant circuit. In this type of heating system, the room is heated by using heat released from the heat transfer circuit of the heat transfer circuit heated by the refrigerant circulating in the refrigerant circuit in the use side heat exchanger.

For example, Patent Document 1 discloses a floor heating apparatus that performs floor heating as this type of heating system. In this floor heating apparatus, a hot water heat exchanger of a secondary circuit (heat transfer circuit) provided with a floor heating panel is connected to a refrigerant circuit. In the hot water heat exchanger, the refrigerant dissipates heat, and the water circulating in the secondary circuit is heated. In the secondary circuit, the hot water heated by the hot water heat exchanger radiates heat from the floor heating panel. Thus, in this floor heating apparatus, the indoor water is heated by the heat of the hot water heated by the refrigerant in the refrigerant circuit being radiated by the floor heating panel. In this floor heating device, the inverter of the compressor of the refrigerant circuit is controlled so that the temperature of the hot water returning from the floor heating panel to the hot water heat exchanger becomes the target temperature.
JP 2000-46417 A

  By the way, in this kind of heating system, it is possible to perform a supercritical refrigeration cycle in which, for example, carbon dioxide is used as the refrigerant in the refrigerant circuit, and the high pressure of the refrigeration cycle is higher than the critical pressure of the refrigerant in the refrigerant circuit. In such a heating system, the amount of heat of the refrigerant that can be used as warm heat decreases as the temperature of the heat medium in the heat transfer circuit that exchanges heat with the refrigerant in the heat source side heat exchanger to which the refrigerant circuit is connected increases. However, even if the amount of heat of the refrigerant that can be used as warm heat decreases, the energy required for refrigerant compression in the compressor of the refrigerant circuit does not decrease. Therefore, the coefficient of performance of the refrigeration cycle in the refrigerant circuit becomes smaller as the temperature of the heat medium in the heat transfer circuit in which the refrigerant exchanges heat with the heat source side heat exchanger connected to the refrigerant circuit becomes higher.

  On the other hand, in the conventional heating system, only the refrigerant circuit that performs the refrigeration cycle becomes the heat source of the heat medium of the heat transfer circuit that radiates heat in the use side heat exchanger. For this reason, in the refrigerant circuit, a certain amount of energy is required in order to obtain the heat used for heating the heat medium of the heat transfer circuit. Therefore, in order to reduce the energy consumption of the refrigerant circuit, it is conceivable to provide heating means for heating the heat medium of the heat transfer circuit separately from the refrigerant circuit.

  However, when a supercritical refrigeration cycle is performed in the refrigerant circuit, if a heating unit is provided separately, the heat source side heat to which the refrigerant circuit is connected depends on the position at which the heating unit heats the heat medium of the heat transfer circuit. There is a possibility that the temperature of the heat medium in the heat transfer circuit returning to the exchanger becomes high, and the coefficient of performance of the refrigeration cycle in the refrigerant circuit is lowered.

  The present invention has been made in view of the above point, and an object of the present invention is to provide a refrigerant in a refrigerant circuit for performing a refrigeration cycle in which a high pressure of the refrigeration cycle is higher than a critical pressure of the refrigerant, and a use side heat exchanger is provided. An object of the present invention is to reduce energy consumption in the refrigerant circuit without reducing the coefficient of performance of the refrigeration cycle in the refrigerant circuit in the heating system for heating the heat medium of the heat transfer circuit.

The first invention includes a heat transfer circuit (30) for circulating a heat medium between a heat source side heat exchanger (50) and a use side heat exchanger (35), and a heat transfer medium of the heat transfer circuit (30). A first heating means (21) and a second heating means (71, 82) for heating the first heating means (21, 82), the first heating means (21) and the second heating means (71, 82). Only the means (21) is constituted by a refrigerant circuit that performs the refrigeration cycle by circulating the refrigerant so that the high pressure of the refrigeration cycle is higher than the critical pressure of the refrigerant. In the heat transfer circuit (30), The first heating means (21) is connected to the refrigerant circuit heat exchanger (50) constituting the heat source side heat exchanger (50), and the first heating means is connected to the refrigerant circuit heat exchanger (50). The heat medium of the heat transfer circuit (30) is heated by the refrigerant of (21), and the first heating means (21) and the second heating means (71, 82) Heating medium heated the heat carrier circuit (30) Te is directed to a heating system (10) utilizing the heat released by the utilization-side heat exchanger (35) to the room heating. And in this heating system (10), the said 2nd heating means (71,82) is the outflow side of the said heat exchanger for refrigerant circuits (50) in the said heat transfer circuit (30), and the said utilization side heat exchanger. (35) is configured to heat the heat medium of the heat transfer circuit (30) with the inflow side of the heat transfer circuit (30), and the heat transfer circuit (30) includes a first passage (58) connected in parallel and A second passage (59) is provided, the refrigerant circuit heat exchanger (50) is disposed in the first passage (58), and the second heating means (71, 82) is connected to the heat transfer circuit ( In addition to the first position between the outflow side of the refrigerant circuit heat exchanger (50) and the inflow side of the use side heat exchanger (35) in 30), the heat transfer circuit (30) While configured to be able to heat the heat transfer medium of the heat transfer circuit (30) even at the second position on the second passage (59),
The second heating means (71, 82) is constituted by a heat medium circuit through which a heat medium flows, and is connected to a solar heat collector (70) having a solar heat collector (76) for collecting solar heat, The second heating means (71) used for heating the heat medium of the heat transfer circuit (30) by heating the heat medium of the heat transfer circuit (30) with the heat medium heated by the solar heat collector (70). , 82) is detected, and when the detected temperature is higher than a predetermined reference temperature, the heat medium of the heat transfer circuit (30) is heated at the first position, and the detected temperature is Control means (55) for controlling the second heating means (71, 82) is provided so as to heat the heat transfer medium of the heat transfer circuit (30) at the second position when the temperature is lower than the reference temperature. ing.

  In the first invention, only the first heating means (21) out of the first heating means (21) and the second heating means (71, 82) is such that the high pressure of the refrigeration cycle is higher than the critical pressure of the refrigerant. The refrigerant circuit is configured to perform a set refrigeration cycle (hereinafter, referred to as “supercritical refrigeration cycle”). That is, the second heating means (71, 82) is constituted by a heating means other than the refrigerant circuit that performs the supercritical refrigeration cycle. The heat medium of the heat transfer circuit (30) is heated by the heat released by the refrigerant in the refrigerant circuit heat exchanger (50) that radiates heat from the refrigerant of the first heating means (21). The heat medium of the heat transfer circuit (30) is also heated by the second heating means (71, 82). In the first aspect of the invention, in addition to the first heating means (21) configured by the refrigerant circuit that performs the supercritical refrigeration cycle, the second heating system is configured by a heating means other than the refrigerant circuit that performs the supercritical refrigeration cycle. The heating means (71, 82) is a heat source for the heat medium of the heat transfer circuit (30). In the heat transfer circuit (30), the second heating means (71, 82) heats the heat medium of the heat transfer circuit (30) downstream of the refrigerant circuit heat exchanger (50). For this reason, in the heat transfer circuit (30), the heat medium returning to the refrigerant circuit heat exchanger (50) is not heated by the second heating means (71, 82).

Based on the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30), the second heat means (71, 82) is the heat medium of the heat transfer circuit (30). The position for heating is selected. Specifically, when the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is higher than the reference temperature, the second heating means (71, 82) Heats the heat medium of the heat transfer circuit (30) at the first position downstream of the refrigerant circuit heat exchanger (50). On the other hand, when the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is lower than the reference temperature, the second heating means (71, 82) is the refrigerant circuit. The heat medium of the heat transfer circuit (30) is heated at a second position parallel to the heat exchanger (50). In the first aspect of the invention, the second heating means (depending on whether the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is higher or lower than the reference temperature). 71, 82) is selected for heating the heat carrier of the heat transfer circuit (30).

In a second aspect based on the first invention, the control means (55), the second heating means used to heat the heating medium in the upper Symbol heat carrier circuit (30) of the heating medium (71,82) When the temperature is detected and the detected temperature is equal to or lower than a predetermined lower limit temperature, the second heating means (71, 82) is controlled so as to stop the heating of the heat transfer circuit (30). It is configured as follows.

In the second invention, based on the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30), the second heating means (71, 82) is the heat transfer circuit. It is determined whether or not the heating medium (30) is heated. Specifically, when the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is higher than the lower limit temperature, the second heating means (71, 82) Performs heating of the heat medium of the heat transfer circuit (30). On the other hand, when the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is lower than the lower limit temperature, the second heating means (71, 82) is heat transferred. Stop heating the heating medium of the circuit (30). In the second aspect of the invention, the second heating means (depending on whether the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is higher or lower than the lower limit temperature). 71, 82) determines whether to heat the heat medium of the heat transfer circuit (30).

According to a third invention, in the first or second invention, the second heating means (71, 82) utilizes the exhaust heat of the power generation device (81) to heat the heat transfer circuit (30). It is comprised so that it may heat.

In the third invention, the exhaust heat of the power generation device (81) is used to heat the heat medium of the heat transfer circuit (30).

According to a fourth invention, in any one of the first to third inventions, the heat transfer circuit (30) is heated by the first heating means (21) and the second heating means (71, 82). A heat storage tank (37) for storing the heated heat medium, and only the heat medium heated by the first heating means (21) and the second heating means (71, 82) is used in the use side heat exchanger. Normal operation for supplying to (35), and the heat medium heated by the first heating means (21) and the second heating means (71, 82) to the use side heat exchanger (35) and the heat storage tank ( 37) both the heat storage operation supplied to both the heat medium heated by the first heating means (21) and the second heating means (71, 82) and the heat medium in the heat storage tank (37). The utilization operation of supplying to the utilization side heat exchanger (35) is selectively performed.

In the fourth invention, the normal operation, the heat storage operation, and the use operation are selectively performed. In normal operation, only the heat medium heated by the first heating means (21) and the second heating means (71, 82) is supplied to the use side heat exchanger (35) without using the heat storage tank (37). Is done. In the heat storage operation, the heat medium heated by the first heating means (21) and the second heating means (71, 82) is supplied to both the use side heat exchanger (35) and the heat storage tank (37). In the heat storage operation, a part of the heat medium heated by the first heating means (21) and the second heating means (71, 82) is supplied to the heat storage tank (37), so the use side heat exchanger (35) The amount of heat of the heat medium supplied to is reduced, and the heating capacity in the use side heat exchanger (35) is reduced. In the use operation, both the heat medium heated by the first heating means (21) and the second heating means (71, 82) and the heat medium in the heat storage tank (37) are transferred to the use side heat exchanger (35). Supplied. In the use operation, the heat medium is also supplied from the heat storage tank (37) to the use side heat exchanger (35), so the amount of heat of the heat medium supplied to the use side heat exchanger (35) increases, The heating capacity in the side heat exchanger (35) is increased. Thus, in this 4th invention, the heating capacity in the utilization side heat exchanger (35) is adjusted by adjusting the heat quantity of the heat medium supplied to the utilization side heat exchanger (35) by the heat storage tank (37). Adjusted.

  In the present invention, in addition to the first heating means (21) configured by the refrigerant circuit that performs the supercritical refrigeration cycle as a heat source of the heat transfer circuit (30), heating other than the refrigerant circuit that performs the supercritical refrigeration cycle The 2nd heating means (71,82) comprised by the means is provided. For this reason, the energy consumption in the 1st heating means (21) comprised by the refrigerant circuit can be reduced. Further, according to the present invention, the second heating means (71, 82) is placed at a predetermined position with respect to the heat transfer circuit (30) with respect to the refrigerant circuit heat exchanger (50) to which the first heating means (21) is connected. In the heat transfer circuit (30), the heat medium returning to the refrigerant circuit heat exchanger (50) is not heated by the second heating means (71, 82). I have to. For this reason, by providing the second heating means (71, 82), the temperature of the heat medium in the heat transfer circuit (30) returning to the refrigerant circuit heat exchanger (50) does not rise, and the first heating means In (21), it is avoided that the amount of heat of the refrigerant that can be used as the heat is reduced. Therefore, the energy consumption in the first heating means (21) can be reduced without reducing the coefficient of performance of the refrigeration cycle in the first heating means (21).

Moreover, in the said 1st invention, in order to heat the heat medium of a heat conveyance circuit (30), the warm temperature obtained with the solar-heat collector (76) is utilized. For this reason, in the 2nd heating means (71,82), in order to obtain the warmth which heats the heat carrier of heat transfer circuit (30), energy is not consumed. Therefore, the energy consumption of the heating system (10) can be reduced.

In the first invention, the second heating is performed depending on whether the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is higher or lower than the reference temperature. The position where the means (71, 82) heats the heat medium of the heat transfer circuit (30) is selected. Here, in the solar heat collector (70), the amount of heat to be obtained changes according to the amount of light incident on the solar heat collector (76). For this reason, in the second heating means (71, 82), depending on the weather, the temperature of the heat medium used for heating the heat medium of the heat transfer circuit (30) may not be so high. The temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is heated by the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30). If the temperature of the heat medium becomes lower, the second heating means (71, 82) cannot heat the heat medium of the heat transfer circuit (30) at a position downstream of the refrigerant circuit heat exchanger (50). The second heating means (71, 82) cannot be used for heating the heat medium of the heat transfer circuit (30).

In the first invention, considering such points, is the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) higher than the reference temperature? The position where the second heating means (71, 82) heats the heat medium of the heat transfer circuit (30) is selected depending on whether the temperature is low. When the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is equal to or lower than the reference temperature, the second heating means (71, 82) The heat medium of the heat transfer circuit (30) is heated not at the first position downstream of the circuit heat exchanger (50) but at the second position parallel to the refrigerant circuit heat exchanger (50). Thus, according to the first aspect of the present invention, the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30), that is, the solar heat collector (76). Since the second heating means (71, 82) can heat the heat medium of the heat transfer circuit (30) at an appropriate position according to the amount of heat obtained, the second heating means (71, 82) is solar heat. The heat obtained from can be used efficiently.

In the second invention, the second heating means depends on whether the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is higher or lower than the lower limit temperature. Whether (71, 82) heats the heat medium of the heat transfer circuit (30) is determined. By the way, when using the heat obtained by the solar heat collector (76), as described above, depending on the weather, the temperature of the heat medium used for heating the heat medium of the heat transfer circuit (30) becomes so high. It may not be possible. When the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is lowered to some extent, the second heating means (71, 82) is changed to the heat transfer circuit (30). By heating the heat medium, the temperature of the heat medium supplied to the use side heat exchanger (35) may be lowered. That is, the second heating means (71, 82) may not be appropriately used for heating the heat medium of the heat transfer circuit (30). In the second invention, in consideration of such points, the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is compared with the lower limit temperature. Thus, it is determined whether or not the second heating means (71, 82) heats the heat medium of the heat transfer circuit (30). Therefore, the second heating means (71, 82) cannot be properly used for heating the heat medium of the heat transfer circuit (30), and the second heating means (71, 82) is not connected to the heat transfer circuit (30). Therefore, the temperature of the heat medium supplied to the use side heat exchanger (35) can be prevented from being lowered by the second heating means (71, 82).

Moreover, in the said 3rd invention, in order to heat the heat medium of a heat conveyance circuit (30), the exhaust heat of a power generator (81) is utilized. For this reason, the energy consumption of a heating system (10) can be reduced.

Moreover, in the said 4th invention, the heating capability in a utilization side heat exchanger (35) is adjusted by adjusting the heat quantity of the heat medium supplied to a utilization side heat exchanger (35) with a thermal storage tank (37). It is possible. Here, in the conventional heating system (for example, the heating system of Cited Document 1), the operating capacity of the compressor is controlled according to the temperature of the hot water returning from the floor heating panel to the hot water heat exchanger. The temperature of the warm water returning to the warm water heat exchanger decreases as the heating load increases. That is, in the conventional heating system, the circulation amount of the refrigerant in the refrigerant circuit is adjusted according to the heating load.

  By the way, when the circulation amount of the refrigerant in the refrigerant circuit changes, the coefficient of performance (COP) of the refrigeration cycle also changes accordingly. The coefficient of performance changes because the performance of the heat exchanger changes with a change in the refrigerant flow rate or the efficiency of the compressor changes with a change in the rotational speed of the compressor. For this reason, in the conventional heating system in which the circulation amount of the refrigerant is adjusted according to the heating load, the circulation amount of the refrigerant in the refrigerant circuit has to be set to a value at which a high coefficient of performance cannot be obtained. There was a risk of longer time. That is, there is a possibility that the time during which the coefficient of performance of the refrigeration cycle in the refrigerant circuit does not become so high may be long.

On the other hand, in the fourth aspect of the invention, the amount of heat of the heat medium supplied to the use side heat exchanger (35) can be adjusted by the heat storage tank (37), so that the first heating constituted by the refrigerant circuit is performed. The heating capacity in the use side heat exchanger (35) can be adjusted without adjusting the circulation amount of the refrigerant in the means (21). For this reason, since the fluctuation range of the circulation amount of the refrigerant in the first heating means (21) is reduced, the time during which the coefficient of performance of the refrigeration cycle in the first heating means (21) does not become so high can be shortened. The operating efficiency of the heating system (10) can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 of the Invention
A first embodiment of the present invention will be described. The first embodiment is a heating system (10) according to the present invention. This heating system (10) is provided with a use side heat exchanger (35) by a refrigerant circuit (21) that performs a supercritical refrigeration cycle and a solar heat utilization circuit (71) that uses the heat obtained from solar heat. The heat transfer circuit (30) is configured to heat the heat medium. This heating system (10) is installed in a general household in a cold region, for example.

<Heat transfer circuit>
As shown in FIG. 1, the heating system (10) includes a heat source side heat exchanger (27) constituted by a plurality of heat source side heat exchangers (50 to 52), and a plurality of usage side heat exchangers (35 ) Is provided with a heat transfer circuit (30) provided with a use side heat exchange section (28). The heat transfer circuit (30) is filled with water as a heat medium. In the heat transfer circuit (30), the heat medium circulates between the heat source side heat exchange unit (27) and the use side heat exchange unit (28).

  The heat source side heat exchanger (27) includes three heat source side heat exchangers (a refrigerant circuit heat exchanger (50), a first solar heat exchanger (51), and a second solar heat exchanger (52)). 50 to 52). In the heat transfer circuit (30), the first solar heat exchanger (51) is disposed in the supply passage (31) extending from the outflow side of the refrigerant circuit heat exchanger (50). That is, the first solar heat exchanger (51) is disposed at the first position downstream of the refrigerant circuit heat exchanger (50). The second solar heat exchanger (52) is disposed in the second passage (59) provided in parallel with the first passage (58) provided with the refrigerant circuit heat exchanger (50). . That is, the second solar heat exchanger (52) is disposed at the second position in parallel with the refrigerant circuit heat exchanger (50). The first passage (58) includes a part of the supply passage (31) and a part of the return passage (32) described later.

  The refrigerant circuit heat exchanger (50) includes a first flow path (50a) and a second flow path (50b), and the fluid in the first flow path (50a) and the fluid in the second flow path (50b) are provided. It is configured to perform heat exchange. In the refrigerant circuit heat exchanger (50), the first flow path (50a) is connected to the heat transfer circuit (30). Each solar heat exchanger (51, 52) includes a first flow path (51a, 52a) and a second flow path (51b, 52b), and the fluid in the first flow path (51a, 52a) The fluid in the second flow path (51b, 52b) is configured to perform heat exchange. In each solar heat exchanger (51, 52), the first flow path (51a, 52a) is connected to the heat transfer circuit (30).

  On the other hand, the use side heat exchange section (28) is constituted by a plurality of use side heat exchangers (35). The plurality of usage side heat exchangers (35) are connected in parallel to each other between the supply side header (33) and the return side header (34). Each use side heat exchanger (35) is configured as a radiator for floor heating installed on the back side of the floor material or a radiator installed in an indoor space.

  The supply passage (31) extends from the outflow side of the refrigerant circuit heat exchanger (50) to the inflow side of each use side heat exchanger (35). In the supply passage (31), an openable first open / close valve (41) is provided between the first solar heat exchanger (51) and the supply header (33). Further, in the first passage (58) on the upstream side of the supply passage (31), the heat medium heated by the refrigerant circuit heat exchanger (50) at a position downstream of the refrigerant circuit heat exchanger (50). A first temperature sensor (16) for measuring the temperature of is provided.

  The return passage (32) extends from the outflow side of each use side heat exchanger (35) to the inflow side of the refrigerant circuit heat exchanger (50). In the return passage (32), a pump (36) having a variable discharge flow rate is provided between the return header (34) and the refrigerant circuit heat exchanger (50). An expansion tank (38) for releasing the pressure of the heat transfer circuit (30) is connected to the suction side of the pump (36) in the return passage (32). Further, a second temperature sensor (for measuring the temperature of the heat medium radiated by each use side heat exchanger (35)) is provided between the return side header (34) and the pump (36) in the return passage (32). 17) is provided. The second passage (59) is provided with a sixth open / close valve (46) that can be freely opened and closed.

  In addition, the heat transfer circuit (30) of the first embodiment is provided with a heat storage tank (37) for storing the heat medium heated by the heat source side heat exchange section (27). The heat storage tank (37) is filled with the heat medium, and the temperature of the heat medium is higher toward the upper side. At the top of the heat storage tank (37), an inflow passage (61) for allowing a warm heat medium to flow into the heat storage tank (37) and an outflow passage (64) for allowing the warm heat medium to flow out from the heat storage tank (37) And are connected. The inflow passage (61) branches off from between the first solar heat exchanger (51) and the first on-off valve (41) in the supply passage (31). The inflow passage (61) is provided with a second on-off valve (42) that can be freely opened and closed. On the other hand, the outflow passage (64) joins between the first on-off valve (41) and the supply-side header (33) in the supply passage (31). The outflow passage (64) is provided with a fifth open / close valve (45) that can be freely opened and closed.

  In addition, a junction passage (63) is connected to the bottom surface of the heat storage tank (37) of the first embodiment. The confluence passage (63) is branched to the first communication passage (62a) and the second communication passage (62b) on the side opposite to the heat storage tank (37). The first communication passage (62a) is connected upstream of the pump (36) in the return passage (32). A fourth open / close valve (44) that can be freely opened and closed is provided in the first communication passage (62a). On the other hand, the second communication passage (62b) is connected downstream of the pump (36) in the return passage (32). A third open / close valve (43) that can be freely opened and closed is provided in the second communication passage (62b).

  In the heat transfer circuit (30) of the first embodiment, only the heat medium heated by the heat source side heat exchange unit (27) is controlled by controlling the first to fifth on-off valves (41 to 45). Normal operation for supplying to the exchange unit (28), and heat storage operation for supplying the heat medium heated in the heat source side heat exchange unit (27) to both the use side heat exchange unit (28) and the heat storage tank (37), One of the three types of operation that uses both the heat medium heated in the heat source side heat exchange unit (27) and the warm heat medium in the heat storage tank (37) to the use side heat exchange unit (28) Is done. Details of each operation will be described later.

<Refrigerant circuit>
The heating system (10) includes a heat pump unit (19) having a refrigerant circuit (21) constituting the first heating means (21). In the refrigerant circuit (21), the supercritical refrigeration cycle is performed by circulating the refrigerant so that the high pressure of the refrigeration cycle is higher than the critical pressure of the refrigerant. The refrigerant circuit (21) is filled with, for example, carbon dioxide as a refrigerant.

  A compressor (22), a refrigerant circuit heat exchanger (50), a decompression mechanism (24), and an outdoor heat exchanger (25) are connected in order to the refrigerant circuit (21). In the supercritical refrigeration cycle in the refrigerant circuit (21), the refrigerant circuit heat exchanger (50) serves as a radiator (gas cooler) and the outdoor heat exchanger (25) serves as an evaporator.

  Specifically, the compressor (22) is configured as a compressor having a fixed operating capacity. The compressor (22) is one in which the electric motor is always operated at a constant rotational speed, and its operating capacity is fixed. The compressor (22) operates continuously without stopping while the heat medium is circulating in the heat transfer circuit (30). Of course, it is possible to employ a compressor having a variable operating capacity as the compressor (22).

  The refrigerant circuit heat exchanger (50) includes a first flow path (50a) connected to the heat transfer circuit (30) and a second flow path (50b) connected to the refrigerant circuit (21). Yes. The refrigerant circuit heat exchanger (50) is configured such that the heat medium in the first flow path (50a) and the refrigerant in the second flow path (50b) exchange heat. The refrigerant circuit heat exchanger (50) is constituted by, for example, a plate heat exchanger.

  The decompression mechanism (24) is configured as an electronic expansion valve with a variable opening. The outdoor heat exchanger (25) is configured as a cross fin type fin-and-tube heat exchanger. An outdoor fan (26) for sending air to the outdoor heat exchanger (25) is provided in the vicinity of the outdoor heat exchanger (25).

<Solar heat utilization circuit>
The heating system (10) includes a solar heat utilization circuit (71) constituting the second heating means (71). The solar heat utilization circuit (71) is connected to a solar heat collector (70) having a solar heat collector (76). The solar heat utilization circuit (71) is configured to heat the heat medium of the heat transfer circuit (30) using the heat obtained from the solar heat collector (70). Below, before explaining a solar-heat utilization circuit (71), a solar-heat collector (70) is demonstrated first.

  The solar heat collector (70) includes a heat collecting side circuit (80) provided with a solar heat collector (76), a heat collecting tank (77), and a heat collector pump (78). The heat collecting side circuit (80) is filled with antifreeze as a heat medium. In the heat collecting side circuit (80), the heat medium discharged from the heat collector pump (78) circulates.

  The solar heat collector (76) is configured by disposing a heat collecting tube through which the heat medium of the heat collecting side circuit (80) flows in a hollow plate-like casing whose surface is constituted by a transparent plate. ing. The solar collector (76) is installed on the roof. In the solar heat collector (76), a heat insulating material is provided below the heat collecting tube. The heat collecting tube is connected to the heat collecting side circuit (80).

  The heat collection tank (77) is for collecting the heat obtained by the solar heat collector (76). The heat collection tank (77) is installed on the ground, for example. A solar heat utilization circuit (71) is connected to the heat collecting tank (77). Inside the heat collecting tank (77), the heat medium of the solar heat utilization circuit (71) is stored. Further, the heat collection tank (77) accommodates a heat exchange section (77a) connected to the heat collection side circuit (80). The heat exchange part (77a) is made of a metallic tube material having a high thermal conductivity. In the heat collection tank (77), the heat medium of the solar heat utilization circuit (71) stored therein is heated by the heat medium of the heat collection side circuit (80) flowing through the heat exchange section (77a).

  In the solar heat collector (70) of the present embodiment, since the heat collection tank (77) is installed at a position away from the solar heat collector (76), the pump (78) is used for circulation of the heat medium. doing. However, depending on the arrangement of the heat collection tank (77), it is possible to use a solar heat collection device (70) that circulates the heat medium by changing the specific gravity of the heat medium due to heating by solar heat without using a pump. is there.

  The solar heat utilization circuit (71) is configured such that a heat medium (for example, water) heated by the solar heat collector (70) circulates. The solar heat utilization circuit (71) is connected to the utilization circuit pump (66), the heat collection tank (77), and the two solar heat exchangers (51, 52) described above. The utilization circuit pump (66) and the heat collecting tank (77) are arranged in the main passage (71a). The utilization circuit pump (66) is arranged upstream of the heat collecting tank (77). Further, on the downstream side of the heat collection tank (77) in the main passage (71a), a third heat medium for measuring the temperature of the heat medium from the heat collection tank (77) toward the solar heat exchanger (51, 52) side is measured. A temperature sensor (18) is provided.

  The two solar heat exchangers (51, 52) are provided in the branch passages (71b, 71c) branched from the main passage (71a), respectively. These solar heat exchangers (51, 52) are connected in parallel to each other. In the solar heat utilization circuit (71), a first branch on-off valve (47) that can be opened and closed on a first branch pipe (71b) provided with a first solar heat exchanger (51) is provided as a second solar heat exchanger. A second branch on-off valve (48) that can be freely opened and closed is provided on the second branch pipe (71c) provided with (52).

  Each solar heat exchanger (51, 52) is connected to the first flow path (51a, 52a) connected to the heat transfer circuit (30) and to each branch passage (71b, 71c) of the solar heat utilization circuit (71). And a connected second flow path (51b, 52b). Each solar heat exchanger (51, 52) is configured such that the heat medium in the first flow path (51a, 52a) and the heat medium in the second flow path (51b, 52b) exchange heat. . Each solar heat exchanger (51, 52) is constituted by, for example, a plate heat exchanger.

<Configuration of controller>
The heating system (10) of Embodiment 1 is provided with a controller (55) that controls the operating state of the heating system (10). The controller (55) constitutes a control means (55).

  The controller (55) controls the operation of the heat transfer circuit (30) based on the measured value (TB) of the second temperature sensor (17). Specifically, the controller (55) selects an operation to be executed from the normal operation, the heat storage operation, and the use operation based on the measurement value (TB) of the second temperature sensor (17), and the selected operation is performed by the heat transfer circuit ( 30) is configured to be executed.

  The controller (55) receives the measured value (TB) of the second temperature sensor (17) and the indoor set temperature (Ts). The controller (55) is preset with a first determination value (T1) and a second determination value (T2) for selecting the operation of the heat transfer circuit (30). The first determination value (T1) is a positive value. The second determination value (T2) is a negative value. The first determination value (T1) and the second determination value (T2) have the same absolute value.

  The controller (55) determines the difference (TB−Ts) between the measured value (TB) of the second temperature sensor (17) and the indoor set temperature (Ts) as the first determination value (T1) and the second determination value ( The operation to be performed is selected by comparing with T2). Specifically, the controller (55), when the following formula 1 is satisfied, that is, the temperature of the heat medium that has passed through each use side heat exchanger (35) is a predetermined numerical range (a range of T2 + Ts or more and T1 + Ts or less). If it is determined that the value is within the range, normal operation is selected. The normal operation is selected when the indoor heating load is not so high or low as shown in FIG. When the controller (55) selects normal operation, the controller opens the first on-off valve (41), opens the second on-off valve (42), the third on-off valve (43), the fourth on-off valve (44), and By setting the fifth on-off valve (45) to the closed state, the heat transfer circuit (30) is caused to perform a normal operation.

Formula 1: T2 ≦ TB−Ts ≦ T1
Further, the controller (55), when the following equation 2 is established, that is, when the temperature of the heat medium that has passed through each use side heat exchanger (35) exceeds the upper limit value (T1 + Ts) within a predetermined numerical range. If it is determined, the heat storage operation is selected. The heat storage operation is selected when the indoor heating load is relatively low and the temperature of the heat medium does not decrease so much in each use side heat exchanger (35). When selecting the heat storage operation, the controller (55) sets the first on-off valve (41), the second on-off valve (42) and the fourth on-off valve (44) to the open state, and the third on-off valve (43) and By setting the fifth on-off valve (45) to a closed state, the heat transfer circuit (30) is caused to perform a heat storage operation. In addition, the controller (55) maintains the discharge flow rate of the pump (36) in a normal operation.

Formula 2: T1 <TB-Ts
Further, the controller (55), when the following expression 3 is established, that is, when the temperature of the heat medium that has passed through each use side heat exchanger (35) falls below a lower limit (T2 + Ts) within a predetermined numerical range. If it is determined, the use operation is selected. The use operation is selected when the indoor heating load is relatively high and the temperature of the heat medium is relatively reduced in each use-side heat exchanger (35). When the controller (55) selects the use operation, the controller opens the first on-off valve (41), the third on-off valve (43), and the fifth on-off valve (45), opens the second on-off valve (42), By setting the fourth on-off valve (44) to the closed state, the heat transfer circuit (30) is caused to perform the use operation. Further, the controller (55) sets the discharge flow rate of the pump (36) to a value larger than that in the normal operation.

Formula 3: TB-Ts <T2
In this embodiment, the controller (55) is based on the difference (TC−TA) between the measurement value (TC) of the third temperature sensor (18) and the measurement value (TA) of the first temperature sensor (16). Controls the operation of the solar heat utilization circuit (71). Specifically, the controller (55) selects the solar heat exchanger (51, 52) that supplies the heat medium from the heat collection tank (77) based on the difference in the measured values (TC-TA), The first branch on-off valve (47) and the second branch on-off valve (48) are controlled so that the heat medium is supplied to the selected solar heat exchanger (51, 52). In addition, the controller (55) can be used so that the heat medium is not supplied from the heat collection tank (77) to the solar heat exchanger (51, 52) depending on the difference in the measured values (TC-TA). The circuit pump (66) is configured to stop. In the first embodiment, the measured value (TA) of the first temperature sensor (16) is used as the value of the temperature of the heat medium at the outlet of the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30). Although it is used, assuming the heat release temperature of the refrigerant in the second flow path (50b) of the heat exchanger for refrigerant circuit (50), heat exchange for the refrigerant circuit in the heat transfer circuit (30) is calculated from the assumed heat release temperature. A value of the temperature of the heat medium at the outlet of the vessel (50) may be assumed. In this case, it is not necessary to provide the first temperature sensor (16).

  The controller (55) receives the measurement value (TA) of the first temperature sensor (16) and the measurement value (TC) of the third temperature sensor (18). In addition, a solar heat exchanger (51, 52) for supplying a heat medium from the heat collection tank (77) is selected for the controller (55), or a solar heat exchanger (51) from the heat collection tank (77). , 52) is preset with a third determination value (T3) and a fourth determination value (T4) for determining whether or not to supply the heat medium. The third determination value (T3) is a positive value. The fourth determination value (T4) is a negative value. The third determination value (T3) and the fourth determination value (T4) have the same absolute value.

  The controller (55) determines whether the difference (TC-TA) in the measurement value is larger or smaller than the third determination value (T3), and further larger or smaller than the fourth determination value, and determines the heat medium. It is determined whether to select a solar heat exchanger (51, 52) to be supplied or to supply a heat medium from the heat collection tank (77) to the solar heat exchanger (51, 52). That is, the measured value (TC) of the third temperature sensor (18) that measures the temperature of the heat medium toward the heat source side heat exchanger (51, 52) in the solar heat utilization circuit (71) is the first temperature sensor (16). The solar heat exchanger (51, 52) for supplying the heat medium is selected depending on whether the temperature is higher or lower than the reference temperature obtained by adding the third determination value (T3) to the measured value (TA). Further, depending on whether the measured value (TC) of the third temperature sensor (18) is higher or lower than the lower limit temperature obtained by adding the fourth determination value (T4) to the measured value (TA) of the first temperature sensor (16). It is then determined whether or not the heat medium is supplied from the heat collecting tank (77) to the solar heat exchanger (51, 52).

  Specifically, the controller (55) selects the first solar heat exchanger (51) as the supply destination of the heat medium from the heat collection tank (77) when the following Equation 4 is satisfied. In the solar heat utilization circuit (71), the temperature of the heat medium toward the solar heat exchanger (51, 52) is the temperature of the heat medium at the outlet of the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30). If it becomes higher to some extent, the first solar heat exchanger (51) is selected. In this case, the controller (55) sets only the first branch opening / closing valve (47) out of the first branch opening / closing valve (47) and the second branch opening / closing valve (48).

Formula 4: TC-TA> T3
The controller (55) selects the second solar heat exchanger (52) as the supply destination of the heat medium from the heat collection tank (77) when the following equation 5 is established. In the solar heat utilization circuit (71), the temperature of the heat medium toward the solar heat exchanger (51, 52) is the temperature of the heat medium at the outlet of the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30). On the other hand, when it becomes substantially equivalent, the second solar heat exchanger (52) is selected. In this case, the controller (55) sets only the second branch opening / closing valve (48) out of the first branch opening / closing valve (47) and the second branch opening / closing valve (48). Furthermore, the controller (55) simultaneously sets the sixth on-off valve (46) to the open state. The sixth on-off valve (46) is closed except when the second solar heat exchanger (52) is selected as the supply destination of the heat medium from the heat collecting tank (77).

Formula 5: T4 ≦ TC−TA ≦ T3
Further, the controller (55) determines that the heat medium is not supplied from the heat collection tank (77) to the solar heat exchanger (51, 52) when the following equation 6 is satisfied. In this case, the controller (55) stops the utilization circuit pump (66).

Formula 6: T4> TC-TA
-Driving action-
Operation | movement of the heating system (10) of this Embodiment 1 is demonstrated.

  First, the operation of the refrigerant circuit (21) will be described. In the refrigerant circuit (21), the refrigerant discharged from the compressor (22) circulates, whereby the refrigerant circuit heat exchanger (50) operates as a radiator and the outdoor heat exchanger (25) serves as the heat absorber. A supercritical refrigeration cycle that operates as In this refrigeration cycle, the opening degree of the decompression mechanism (24) is adjusted as appropriate. The compressor (22) is continuously operated while the heating system (10) is powered on, that is, while the pump (36) of the heat transfer circuit (30) is operating.

  Specifically, the refrigerant discharged from the compressor (22) dissipates heat to the heat medium of the heat transfer circuit (30) and is cooled by the refrigerant circuit heat exchanger (50). The refrigerant cooled by the refrigerant circuit heat exchanger (50) is depressurized by the decompression mechanism (24), and evaporates by absorbing heat from the air sent by the outdoor fan (26) in the outdoor heat exchanger (25). The refrigerant evaporated in the outdoor heat exchanger (25) returns to the compressor (22), is compressed, and is discharged again. The operation of the refrigerant circuit (21) is the same regardless of the type of operation of the heat transfer circuit (30).

  Next, the operation of the solar heat collector (70) will be described. In the solar heat collector (70), the heat collector pump (78) is operated. The operation of the heat collector pump (78) is performed, for example, while sunlight is incident on the solar heat collector (76).

  In the heat collecting side circuit (80), when passing through the solar heat collector (76), the heat medium is heated by the heat collecting tube heated by the solar heat, and the heat medium heated by the solar heat collector (76) is collected. It flows into the heat exchange part (77a) in the heat tank (77). The heat medium passing through the heat exchanging section (77a) is cooled by releasing heat to the heat medium of the solar heat utilization circuit (71) stored in the heat collecting tank (77). The heat medium of the solar heat utilization circuit (71) stored in the heat collecting tank (77) is heated. The heat medium cooled by the heat exchange part (77a) is heated again when passing through the solar heat collector (76). As described above, in the solar heat collecting apparatus (70), the heat medium circulates in the heat collecting side circuit (80), whereby the heat obtained from the solar heat is collected in the heat collecting tank (77).

  Next, the operation of the solar heat utilization circuit (71) will be described. In the solar heat utilization circuit (71), the utilization circuit pump (66) is operated. The operation circuit pump (66) is not operated when the heat medium in the heat transfer circuit (30) cannot be heated by the heat collected in the heat collecting tank (77).

  Specifically, in the solar heat utilization circuit (71), as described above, based on the measurement value of the third temperature sensor (18), the solar heat exchanger (supplied with the heat medium from the heat collecting tank (77)) ( 51, 52) is selected. In the solar heat utilization circuit (71), the heat medium circulates between the selected solar heat exchanger (51, 52) and the heat collection tank (77). In the solar heat exchanger (51, 52) supplied with the heat medium from the heat collecting tank (77), the supplied heat medium dissipates heat to the heat medium of the heat transfer circuit (30) and is cooled.

  Next, the operation of the heat transfer circuit (30) will be described. Hereinafter, the operation of the heat transfer circuit (30) will be described in the order of normal operation, heat storage operation, and use operation.

<Normal operation>
In the normal operation, as shown in FIG. 3, the first on-off valve (41) is set to the open state, and the second on-off valve (42), the third on-off valve (43), the fourth on-off valve (44) and the second on-off valve (44). 5 The on-off valve (45) is set to the closed state. In the heat transfer circuit (30), the heat medium heated by the heat source side heat exchange section (27) flows into the supply side header (33) through the supply passage (31). In the supply side header (33), the heat medium is distributed to each use side heat exchanger (35). In each usage-side heat exchanger (35), the distributed heat medium dissipates heat into the room and is cooled. The heat medium radiated by each use-side heat exchanger (35) merges with the heat medium radiated by the other use-side heat exchanger (35) at the return-side header (34), and the heat source-side heat exchange section (27) It is heated again.

  In the heat transfer circuit (30), the heat medium circulates between the heat source side heat exchange section (27) and each use side heat exchanger (35), so that the refrigerant circuit (21) and the solar heat use circuit (71) Is transmitted to the room through the heat medium of the heat transfer circuit (30) to heat the room. The point that the heat medium circulates between the heat source side heat exchange section (27) and each use side heat exchanger (35) is the same in the heat storage operation and the use operation described later.

<Heat storage operation>
In the heat storage operation, as shown in FIG. 4, the first on-off valve (41), the second on-off valve (42), and the fourth on-off valve (44) are set in the open state, and the third on-off valve (43) and the second on-off valve (43) 5 The on-off valve (45) is set to the closed state. The discharge flow rate of the pump (36) is set to the same value as in normal operation. Hereinafter, differences from the normal operation will be described.

  In the heat transfer circuit (30), since the fourth on-off valve (44) is in the open state, the heat medium under the heat storage tank (37) is sucked into the pump (36) through the first communication passage (62a). And flows out of the heat storage tank (37). The heat medium that has flowed out of the heat storage tank (37) merges with the heat medium that has passed through each use side heat exchanger (35), and is sent to the heat source side heat exchange section (27). Further, in the heat transfer circuit (30), since the second on-off valve (42) is in an open state, a part of the heat medium flowing through the supply passage (31) passes through the heat storage tank (37 ). A heat medium having the same flow rate as the flow rate flowing out from the first communication passage (62a) flows into the heat storage tank (37). In the heat storage tank (37), the high temperature heat medium heated by the heat source side heat exchange section (27) flows in and the lower temperature heat medium flows out, so the amount of heat increases.

  In the heat storage operation, a part of the heat medium heated in the heat source side heat exchange section (27) is supplied to the heat storage tank (37), so that the warm heat medium supplied to each use side heat exchanger (35) The flow rate is reduced compared to normal operation. Accordingly, since the amount of heat supplied to each use side heat exchanger (35) is smaller than that in the normal operation, the heating capacity in each use side heat exchanger (35) is lower than that in the normal operation.

<Usage behavior>
In the use operation, as shown in FIG. 5, the first on-off valve (41), the third on-off valve (43), and the fifth on-off valve (45) are set in the open state, and the second on-off valve (42) and the second on-off valve (42) 4 The on-off valve (44) is set to the closed state. The discharge flow rate of the pump (36) is set to a larger value than in normal operation. Hereinafter, differences from the normal operation will be described.

  In the heat transfer circuit (30), since the fifth on-off valve (45) is in the open state, the warm heat medium in the upper layer of the heat storage tank (37) flows out through the outflow passage (64). The warm heat medium that has flowed out of the heat storage tank (37) merges with the heat medium heated in the heat source side heat exchange section (27), and is supplied to each use side heat exchanger (35). In the heat transfer circuit (30), since the third on-off valve (43) is in an open state, a part of the heat medium discharged from the pump (36) stores heat through the second communication passage (62b). Supplied to the tank (37). A heat medium having the same flow rate as the flow rate flowing out from the outflow passage (64) flows into the heat storage tank (37). In the heat storage tank (37), the high-temperature heat medium in the upper layer flows out, and the relatively low-temperature heat medium after heat dissipation flows in, so the amount of heat is reduced.

  In use operation, a warm heat medium is supplied not only from the heat source side heat exchanger (27) but also from the heat storage tank (37) to each use side heat exchanger (35), so each use side heat exchanger (35) The warm heat medium supplied to the is increased in comparison with the normal operation. Accordingly, since the amount of heat supplied to each use side heat exchanger (35) is larger than that in the normal operation, the heating capacity in each use side heat exchanger (35) is higher than that in the normal operation.

-Effect of Embodiment 1-
In the first embodiment, as a heat source for the heat transfer circuit (30), in addition to the refrigerant circuit (21) that performs the supercritical refrigeration cycle, solar heat utilization that is configured by a circuit other than the refrigerant circuit that performs the supercritical refrigeration cycle A circuit (71) is provided. For this reason, the energy consumption in a refrigerant circuit (21) can be reduced. Further, according to the first embodiment, the solar heat utilization circuit (71) is in a predetermined position with respect to the heat of the heat transfer circuit (30) with respect to the refrigerant circuit heat exchanger (50) to which the refrigerant circuit (21) is connected. By heating the medium, the heat transfer circuit (30) prevents the heat medium returning to the refrigerant circuit heat exchanger (50) from being heated by the second heating means (71, 82). . Therefore, by providing the solar heat utilization circuit (71), the temperature of the heat transfer circuit (30) returning to the refrigerant circuit heat exchanger (50) does not increase, and the refrigerant circuit (21) It is avoided that the amount of heat of the refrigerant that can be used as warm heat is reduced. Therefore, energy consumption in the refrigerant circuit (21) can be reduced without reducing the coefficient of performance of the refrigeration cycle in the refrigerant circuit (21).

  In the first embodiment, the heat obtained by the solar heat collector (76) is used to heat the heat medium of the heat transfer circuit (30). For this reason, in the solar heat utilization circuit (71), energy is not consumed in order to obtain the heat for heating the heat medium of the heat transfer circuit (30). Therefore, the energy consumption of the heating system (10) can be reduced.

  In the first embodiment, the solar heat utilization circuit (71) depends on whether the temperature of the heat medium of the solar heat utilization circuit (71) used for heating the heat medium of the heat transfer circuit (30) is higher or lower than the reference temperature. A position for heating the heat medium of the heat transfer circuit (30) is selected. When the temperature of the heat medium of the solar heat utilization circuit (71) used for heating the heat medium of the heat transfer circuit (30) is equal to or lower than the reference temperature, the solar heat utilization circuit (71) is connected to the refrigerant circuit heat exchanger ( The heat medium of the heat transfer circuit (30) is heated not at the first position downstream of 50) but at the second position parallel to the refrigerant circuit heat exchanger (50). Thus, according to the first embodiment, the temperature of the heat medium of the solar heat utilization circuit (71) used for heating the heat medium of the heat transfer circuit (30), that is, the amount of heat obtained by the solar heat collector (76). Accordingly, the solar heat utilization circuit (71) can heat the heat medium of the heat transfer circuit (30) at an appropriate position, so that the solar heat utilization circuit (71) efficiently uses the heat obtained from the solar heat. be able to.

  Moreover, in this Embodiment 1, a solar-heat utilization circuit (71) carries out heat conveyance by comparing the temperature of the heat medium of the solar-heat utilization circuit (71) used for heating of the heat medium of a heat-conveyance circuit (30) with minimum temperature. It is determined whether to heat the heat medium of the circuit (30). Therefore, the temperature of the heat medium of the solar heat utilization circuit (71) used for heating the heat medium of the heat transfer circuit (30) is low, and the solar heat utilization circuit (71) is appropriately used for heating the heat medium of the heat transfer circuit (30). Since the solar heat utilization circuit (71) does not heat the heat medium of the heat transfer circuit (30) when it cannot be used, the temperature of the heat medium supplied to the use side heat exchanger (35) is solar heat. It is possible to avoid a drop by the utilization circuit (71).

  In Embodiment 1, the amount of heat of the heat medium supplied to the use-side heat exchanger (35) is adjusted by the heat storage tank (37), so that the amount of circulation of the refrigerant in the refrigerant circuit (21) is not adjusted. In addition, it is possible to adjust the heating capacity in the use side heat exchanger (35). For this reason, since the fluctuation | variation range of the circulation amount of the refrigerant | coolant in a refrigerant circuit (21) becomes small, the time when the coefficient of performance of the refrigerating cycle in a refrigerant circuit (21) does not become a very high value can be shortened, and a heating system (10 ) Driving efficiency can be improved.

  In the first embodiment, the solar utilization circuit (71) in which the amount of heat obtained by the weather varies is the heat source of the heat medium of the heat transfer circuit (30). For this reason, when the amount of heat of the heat medium supplied to the use side heat exchanger (35) cannot be adjusted by the heat storage tank (37), along with the variation of the amount of heat obtained by the solar use circuit (71) The fluctuation range of the refrigerant circulation amount in the refrigerant circuit (21) may be increased. Therefore, even if solar heat is used, there is a possibility that the time during which the coefficient of performance of the refrigeration cycle does not become so high may be further increased. On the other hand, according to this Embodiment 1, the fluctuation | variation of the heat amount obtained by a solar utilization circuit (71) is relieve | moderated by the thermal storage tank (37). For this reason, even if the amount of heat obtained by the solar utilization circuit (71) fluctuates, the influence on the circulation amount of the refrigerant in the refrigerant circuit (21) is small. Therefore, by providing the solar utilization circuit (71), it is possible to avoid an increase in the time during which the coefficient of performance of the refrigeration cycle is not so high.

  In the first embodiment, a compressor having a fixed operating capacity is used as the compressor (22) of the refrigerant circuit (21). For this reason, by designing the refrigerant circuit (21) so that the coefficient of performance in the operating capacity of the compressor (22) is high, it is possible to operate in a state where the coefficient of performance is always high. Therefore, the operating efficiency of the heating system (10) can be improved.

  In the first embodiment, the compressor (22) continuously operates while the heat medium is circulated in the heat transfer circuit (30), so that the refrigerant circuit (21) to the heat transfer circuit (30 ) Is continuously supplied with heat. For this reason, it is possible to make the output calorie | heat amount per unit time of a refrigerant circuit (21) small. Therefore, the configuration of the refrigerant circuit (21) including the compressor (22) can be reduced in size. Moreover, since the energy loss accompanying the start / stop of the compressor (22) can be eliminated, the operating efficiency of the heating system (10) can be improved.

  In the first embodiment, since the operation of the heat transfer circuit (30) is controlled using the temperature of the heat medium that has passed through the use side heat exchanger (35), the heat transfer circuit ( The operation of 30) is switched. Therefore, the heating capacity of the use side heat exchanger (35) can be appropriately adjusted according to the heating load.

  Further, in the first embodiment, by controlling the discharge flow rate of the pump (36), the use operation increases the flow rate of the warm heat medium supplied to the use side heat exchanger (35) compared to the normal operation. I have to. Therefore, the heating capacity in the use side heat exchanger (35) can be efficiently increased in the use operation.

-Modification 1 of Embodiment 1-
A first modification of the first embodiment will be described. In the heat transfer circuit (30) of the first modified example, the solar heat exchanger (52) is disposed only at the second parallel position of the refrigerant circuit heat exchanger (50) as shown in FIG. ing.

  This arrangement is such that the temperature at the outlet of the solar heat collector (76) in the heat collecting side circuit (80) of the solar heat collecting device (70) is the same as that of the heat exchanger (50) for the refrigerant circuit in the heat transfer circuit (30). This is adopted when it is assumed that the temperature is equal to the temperature of the outlet heat medium. In the first modification, the flow rate of the heat medium in the refrigerant circuit heat exchanger (50) is reduced by the amount that the heat medium flows through the second passage (59) provided with the solar heat exchanger (51, 52). Therefore, in the refrigerant circuit (21), the amount of heat necessary for heating the heat medium of the heat transfer circuit (30) is reduced. Therefore, the input of the compressor (22) of the refrigerant circuit (21) can be reduced, and the energy consumption in the refrigerant circuit (21) can be reduced.

-Modification 2 of Embodiment 1
A second modification of the first embodiment will be described. In the heat transfer circuit (30) of Modification 2, the solar heat exchanger (51) is disposed only at the first position downstream of the refrigerant circuit heat exchanger (50) as shown in FIG. ing.

  In this arrangement, the temperature at the outlet of the solar heat collector (76) in the heat collecting side circuit (80) of the solar heat collecting device (70) is changed to the heat exchanger (50) for the refrigerant circuit in the heat transfer circuit (30). This is adopted when it is assumed that the temperature of the heat medium at the outlet of the heat exchanger becomes higher to some extent. In Modification 2, since the heat medium is further heated downstream of the heat exchanger (50) for the refrigerant circuit in the heat transfer circuit (30), the heat radiation temperature of the refrigerant in the refrigerant circuit (21) is changed to the heat transfer circuit (30). It can be set to a lower value than when the solar heat exchanger (51) is not provided at the first position 30). Therefore, the input of the compressor (22) of the refrigerant circuit (21) can be reduced, and the energy consumption in the refrigerant circuit (21) can be reduced.

<< Embodiment 2 of the Invention >>
A second embodiment of the present invention will be described. The second embodiment is a heating system (10) according to the present invention. Below, a different point from the said Embodiment 1 is demonstrated.

  In the second embodiment, as shown in FIG. 8, an exhaust heat side circuit (82) is provided instead of the solar heat utilization circuit (71). The exhaust heat side circuit (82) is connected to a power generation device (81) configured to be supplied with fuel and generate electric power and exhaust heat. The exhaust heat side circuit (82) is configured to heat the heat medium of the heat transfer circuit (30) using the exhaust heat of the power generation device (81). Hereinafter, before describing the exhaust heat side circuit (82), the power generator (81) will be described first.

  The power generation device (81) is constituted by, for example, a device provided with a heat engine such as a gas turbine or a gas engine, or a device provided with a fuel cell. The electric power generated by the power generation device (81) is used for the operation of the heat pump unit (19), for example.

  In the power generation device (81) provided with the heat engine, the heat engine is configured to receive supply of air and fuel, and convert the combustion energy of the fuel into motive power for driving. In this power generation device (81), the generated electric power is output, and exhaust heat such as combustion exhaust gas of the heat engine is output as warm heat.

  Further, in the power generation device (81) provided with the fuel cell, power is generated by the fuel cell, and electric power is output from the fuel cell. In this power generation device (81), the exhaust heat of at least one of the reforming section that generates hydrogen supplied to the fuel cell by reforming the fuel and the fuel cell is output as warm heat. The power generation device (81) provided with the fuel cell is one that is directly supplied with hydrogen fuel without having a reforming unit, or one that uses liquid hydrocarbons (eg, methanol, ethanol) as the fuel. Also good.

  The exhaust heat side circuit (82) is configured such that a heat medium (for example, water or engine coolant) heated by the exhaust heat of the power generation device (81) circulates. An exhaust heat side pump (not shown) for circulating the heat medium and an exhaust heat exchanger (83) are connected to the exhaust heat side circuit (82). The heat exchanger for exhaust heat (83) is constituted by, for example, a plate heat exchanger. In the exhaust heat side circuit (82), the heat medium passing through the power generator (81) is heated by the exhaust heat of the power generator (81), and the heat medium heated by the exhaust heat of the power generator (81) is used for exhaust heat. The heat exchanger (83) heats the heat transfer circuit (30) heat medium.

  The heat exchanger for exhaust heat (83) is arranged in parallel with the heat exchanger for refrigerant circuit (50). In this arrangement, the temperature of the heat medium at the outlet of the power generator (81) in the exhaust heat side circuit (82) is the temperature of the heat medium at the outlet of the heat exchanger for refrigerant circuit (50) in the heat transfer circuit (30). It is used when it is assumed that This arrangement is employed, for example, when the power generation device (81) is provided with a gas engine.

  In the second embodiment, the flow rate of the heat medium in the refrigerant circuit heat exchanger (50) is reduced by the amount that the heat medium flows through the second passage (59) provided with the heat exchanger for exhaust heat (83). In the refrigerant circuit (21), the amount of heat necessary for heating the heat medium of the heat transfer circuit (30) is reduced. Therefore, the input of the compressor (22) of the refrigerant circuit (21) can be reduced, and the energy consumption in the refrigerant circuit (21) can be reduced.

-Effect of Embodiment 2-
In the second embodiment, the exhaust heat of the power generation device (81) is used to heat the heat medium of the heat transfer circuit (30). For this reason, the energy consumption of a heating system (10) can be reduced.

-Modification of Embodiment 2-
A modification of the second embodiment will be described. In this modification, in the heat transfer circuit (30), as shown in FIG. 9, the heat exchanger for exhaust heat (83) is disposed downstream of the heat exchanger for refrigerant circuit (50) in the heat transfer circuit (30). Has been placed.

  In this arrangement, the temperature of the heat medium at the outlet of the power generator (81) in the exhaust heat side circuit (82) is the temperature of the heat medium at the outlet of the heat exchanger for refrigerant circuit (50) in the heat transfer circuit (30). This is used when it is assumed that the level will be higher to some extent. In this modification, since the heat medium is further heated downstream of the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30), the heat release temperature of the refrigerant in the refrigerant circuit (21) is set to the heat transfer circuit (30). ) In the first position can be set to a lower value than when there is no heat exchanger for exhaust heat (83). Therefore, the input of the compressor (22) of the refrigerant circuit (21) can be reduced, and the energy consumption in the refrigerant circuit (21) can be reduced.

<< Embodiment 3 of the Invention >>
Embodiment 3 of the present invention will be described. The third embodiment is a heating system (10) according to the present invention. As shown in FIG. 10, the heating system (10) includes a refrigerant circuit (21), a solar heat utilization circuit (71), and an exhaust heat side circuit (82) provided as a heat source for the heat transfer circuit (30). Yes.

  As in the first embodiment, the solar heat utilization circuit (71) is provided between the outflow side of the refrigerant circuit heat exchanger (50) and the inflow side of the utilization side heat exchanger (35) in the heat transfer circuit (30). And the second position in the second passage (59) parallel to the first passage (58) in which the refrigerant circuit heat exchanger (50) is provided in the heat transfer circuit (30). Thus, the heat medium of the heat transfer circuit (30) can be heated. As in the first embodiment, the operation of the solar heat utilization circuit (71) is the difference (TC−) between the measured value (TC) of the third temperature sensor (18) and the measured value (TA) of the first temperature sensor (16). TA).

  Similarly to the second embodiment, the exhaust heat side circuit (82) receives the heat medium of the heat transfer circuit (30) in a position parallel to the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30). It is configured to heat.

  In addition, as shown in FIG. 11, the solar heat utilization circuit (71) is a second parallel to the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30), as in the first modification of the first embodiment. The heating medium of the heat transfer circuit (30) may be heated only at the position. Further, as shown in FIG. 12, the solar heat utilization circuit (71) is the first downstream of the refrigerant circuit heat exchanger (50) in the heat transfer circuit (30), as in the second modification of the first embodiment. The heating medium of the heat transfer circuit (30) may be heated only at the position.

-Modification of Embodiment 3-
A modification of the third embodiment will be described. In this modification, in the heat transfer circuit (30), as shown in FIG. 13, the heat exchanger for exhaust heat (83) is replaced with a refrigerant in the heat transfer circuit (30), as in the modification of the second embodiment. The heat medium of the heat transfer circuit (30) is heated downstream of the circuit heat exchanger (50).

  The solar heat utilization circuit (71) may be configured to heat the heat medium of the heat transfer circuit (30) only at the second position, similarly to the first modification of the first embodiment. Similarly to the second modification of the first embodiment, the heat medium of the heat transfer circuit (30) may be heated only at the first position.

<< Embodiment 4 of the Invention >>
Embodiment 4 of the present invention will be described. This Embodiment 4 is a heating hot-water supply system (11) provided with the heating system (10) which concerns on this invention. Below, a different point from the said Embodiment 1 is demonstrated. In addition, it is possible to apply the heating system of all said embodiment to the heating hot-water supply system (11) of this Embodiment 4. FIG.

  As shown in FIG. 14, in Embodiment 4, the indoor side circuit (100) through which the heat medium that exchanges heat with the water in the heat transfer circuit (30) circulates is connected to the use side heat exchanger (35). Yes. In addition, the number of use side heat exchangers (35) is one. In this Embodiment 4, since the heat exchanger installed indoors is provided in the indoor circuit (100), it is not necessary to arrange the heat transfer circuit (30) indoors. Therefore, it is possible to incorporate the refrigerant circuit (21) and the heat transfer circuit (30) into one outdoor unit.

  The indoor circuit (100) is provided with a plurality of indoor heat exchangers (105). The plurality of indoor heat exchangers (105) are connected in parallel to each other between the headers (103, 104). The indoor heat exchanger (105) is configured as a floor heating radiator installed on the back side of the floor material or a radiator installed in the indoor space.

  The indoor circuit (100) is provided with an indoor pump (101) having a constant discharge flow rate between the return side header (104) and the use side heat exchanger (35). An expansion tank (102) for releasing the pressure in the indoor circuit (100) is connected to the suction side of the indoor pump (101).

  A water supply circuit (90) is connected to the heat transfer circuit (30). The water supply circuit (90) includes a city water side passage (91) for supplying city water to the heat transfer circuit (30) and a use side passage extending to the use side such as a bathtub in a bathroom and a shower or a kitchen faucet. (92). The exit end of the city water side passageway (91) is connected to the junction passageway (63). On the other hand, the inlet end of the use side passageway (92) is connected to the outflow passageway (64).

  The use side passage (92) is provided with a mixing valve (95). A branch passage (93) branched from the city water side passage (91) is connected to the mixing valve (95). The mixing valve (95) is configured to be able to adjust the flow rate ratio between the warm water flowing through the use side passage (92) and the water flowing from the branch passage (93) according to the water temperature required on the use side. .

  The city water side passageway (91) is provided with a check valve (98) that allows only the flow of water toward the heat storage tank (37). An escape passage (97) for releasing the pressure of the heat storage tank (37) is connected to the top of the heat storage tank (37). A relief valve (96) is provided in the relief passage (97).

-Driving action-
In the heating and hot water supply system (11) of the fourth embodiment, an operation when using hot water on the use side of the water supply circuit (90) will be described.

  When the heat transfer circuit (30) performs normal operation, as shown in FIG. 15, low-temperature water flows into the heat storage tank (37) through the city water side passageway (91) and is used from the heat storage tank (37). Hot water flows out through the side passage (92). In the heat storage tank (37), the amount of hot water decreases.

  When the heat transfer circuit (30) performs a heat storage operation, as shown in FIG. 16, a part of warm water flowing through the supply passage (31) flows into the heat storage tank (37) through the inflow passage (61). From the heat storage tank (37), hot water flows out through the use side passage (92) and low temperature water flows out through the junction passage (63). The water from the city water side passageway (91) joins the joining passageway (63).

  When the heat transfer circuit (30) performs a use operation, as shown in FIG. 17, the heat storage tank (37) has a part of the water discharged from the pump (36) through the junction passage (63) and the city. Water supplied from the water side passageway (91) flows in. Hot water flows out of the heat storage tank (37) through the outflow passageway (64). The high-temperature water flowing out from the heat storage tank (37) branches into the supply passage (31) side and the use side passage (92).

<< Other Embodiments >>
You may comprise the said embodiment like the following modifications.

-First modification-
In the first modification, as shown in FIG. 18, cooling heat exchangers (107, 107) are provided in the return passage (32) of the heat transfer circuit (30). A plurality of cooling heat exchangers (107, 107) are provided and connected in parallel between the headers (108, 109). Each cooling heat exchanger (107) is accommodated in an indoor unit installed in the room (not shown). Each indoor unit is provided with an indoor fan (110) that sends air to the cooling heat exchanger (107).

  In this first modification, the heat medium radiated by each use side heat exchanger (35) is further cooled by exchanging heat with the air sent by the indoor fan (110) in each cooling heat exchanger (107). The The air heated by each cooling heat exchanger (107) is supplied indoors. The temperature of the heat medium returning to the refrigerant circuit heat exchanger (50) is lower than that in the case where there is no cooling heat exchanger (107).

  In this 1st modification, it returns to the heat exchanger (50) for refrigerant circuits by utilizing the heat of the heat medium which passed each utilization side heat exchanger (35) with each heat exchanger (107) for cooling. The temperature of the heat medium is lowered, and the temperature of the refrigerant radiated by the refrigerant circuit heat exchanger (50) is also lowered (for example, about 35 ° C.). That is, the amount of heat of the refrigerant that can be used as warm heat increases. At this time, the energy required to compress the refrigerant in the compressor (22) does not increase. Therefore, by providing the cooling heat exchanger (107), it is possible to obtain a high coefficient of performance in the refrigerant circuit (21).

-Second modification-
In the second modification, as shown in FIG. 19, the heat transfer circuit (30) is provided with two pumps of a main pump (36) and a sub pump (39). The main pump (36) is disposed in the return passage (32). The sub pump (39) is disposed in the second communication passage (62b). In the second modification, the return passage (32) side of the second communication passage (62b) is connected to the suction side of the main pump (36).

  The controller (55) operates the sub pump (39) only during the use operation. As shown in FIG. 19, the auxiliary pump (39) sends a part of the heat medium flowing through the return passage (32) to the lower part of the heat storage tank (37) during the use operation, and stores heat through the outflow passage (64). Allow the warm heat transfer medium in the tank (37) to flow out. Note that the discharge flow rate of the main pump (36) during the use operation is the same as the normal operation value, unlike the above embodiment. That is, the discharge flow rate of the main pump (36) is always constant. For this reason, a pump with a fixed discharge flow rate can be used for the main pump (36).

  In the second modification, the flow rate of the heat medium sent to the lower part of the heat storage tank (37) during the use operation is determined by the discharge flow rate of the sub pump (39). In the heat storage tank (37), the warm heat medium supplied to the use side heat exchanger (35) is pushed out by the heat medium sent to the lower part. Therefore, the flow rate of the warm heat medium supplied from the heat storage tank (37) to the usage-side heat exchanger (35) during the usage operation is determined by the discharge flow rate of the sub pump (39). The flow rate of the warm heat medium supplied from the heat storage tank (37) to the use side heat exchanger (35) can be easily set to a desired flow rate.

-Third modification-
About the said embodiment, the solar-heat collector (76) may be directly connected to the solar-heat utilization circuit (71). In this case, the solar heat collecting device (70) is not provided with the heat collecting tank (77) or the heat collecting side circuit (80).

-Fourth modification-
In the above embodiment, the controller (55) selects the operation of the heat transfer circuit (30) using the temperature of the heat medium that has passed through the use side heat exchanger (35), but the use side heat exchanger ( The operation of the heat transfer circuit (30) may be selected using the temperature of the heat medium in the course of passing through 35). In this case, the second temperature sensor (17) is provided in the use side heat exchanger (35).

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a heating system that heats the heat medium of the heat transfer circuit provided with the use side heat exchanger by the refrigerant of the refrigerant circuit.

It is a schematic block diagram of the heating system which concerns on this Embodiment 1. FIG. It is a graph which shows the relationship between the operation | movement of the heat transfer circuit in the heating system which concerns on this Embodiment 1, and a heating load. It is a schematic block diagram which shows the flow of the water of the heat transfer circuit during normal operation | movement of the heating system which concerns on this Embodiment 1. FIG. It is a schematic block diagram which shows the flow of the water of the heat transfer circuit during the heat storage operation | movement of the heating system which concerns on this Embodiment 1. FIG. It is a schematic block diagram which shows the flow of the water of the heat conveyance circuit during utilization operation | movement of the heating system which concerns on this Embodiment 1. It is a schematic block diagram of the heating system which concerns on the modification 1 of this Embodiment 1. It is a schematic block diagram of the heating system which concerns on the modification 2 of this Embodiment 1. It is a schematic block diagram of the heating system which concerns on this Embodiment 2. FIG. It is a schematic block diagram of the heating system which concerns on the modification of this Embodiment 2. It is a schematic block diagram of the heating system which concerns on this Embodiment 3. It is a schematic block diagram of another form of the heating system which concerns on this Embodiment 3. It is a schematic block diagram of another form of the heating system which concerns on this Embodiment 3. It is a schematic block diagram of the heating system which concerns on the modification of this Embodiment 3. It is a schematic block diagram of the heating hot-water supply system which concerns on this Embodiment 4. It is a schematic block diagram which shows the flow of the water of the heat transfer circuit during normal operation of the heating hot-water supply system which concerns on this Embodiment 4, and the circuit for water supply. It is a schematic block diagram which shows the flow of the water of the heat transfer circuit during the heat storage operation | movement of the heating hot-water supply system which concerns on this Embodiment 4, and the circuit for water supply. It is a schematic block diagram which shows the flow of the water of the heat transfer circuit during the utilization operation | movement of the heating hot-water supply system which concerns on this Embodiment 4, and the circuit for water supply. It is a schematic block diagram of the heating system which concerns on the 1st modification of other embodiment. It is a schematic block diagram of the heating system which concerns on the 2nd modification of other embodiment.

10 Heating system 21 Refrigerant circuit (first heating means)
Reference Signs List 30 Heat transfer circuit 35 User side heat exchanger 36 Pump 37 Heat storage tank 50 Heat exchanger for refrigerant circuit (heat source side heat exchanger)
51 First solar heat exchanger (heat source side heat exchanger)
52 Second solar heat exchanger (heat source side heat exchanger)
55 Controller (Control means)
70 Solar thermal collector 71 Solar thermal utilization circuit (second heating means)
76 Solar collector 77 Heat collection tank

Claims (4)

A heat transfer circuit (30) for circulating a heat medium between the heat source side heat exchanger (50) and the use side heat exchanger (35);
A first heating means (21) and a second heating means (71, 82) for heating the heat medium of the heat transfer circuit (30);
Of the first heating means (21) and the second heating means (71, 82), only the first heating means (21) is a refrigerant so that the high pressure of the refrigeration cycle is higher than the critical pressure of the refrigerant. Is constituted by a refrigerant circuit that performs a refrigeration cycle by circulating
In the heat transfer circuit (30), the first heating means (21) is connected to the refrigerant circuit heat exchanger (50) constituting the heat source side heat exchanger (50), and the refrigerant circuit heat exchange is performed. The heat medium of the heat transfer circuit (30) is heated by the refrigerant of the first heating means (21) in the vessel (50),
The heat medium of the heat transfer circuit (30) heated by the first heating means (21) and the second heating means (71, 82) releases the heat released by the use side heat exchanger (35) in the room. A heating system used for heating,
The second heating means (71, 82) is disposed between the outflow side of the refrigerant circuit heat exchanger (50) and the inflow side of the use side heat exchanger (35) in the heat transfer circuit (30). The heat transfer circuit (30) is configured to heat the heat medium ,
The heat transfer circuit (30) includes a first passage (58) and a second passage (59) connected in parallel, and the first passage (58) includes the refrigerant circuit heat exchanger (50). ) Is placed,
The second heating means (71, 82) is disposed between the outflow side of the refrigerant circuit heat exchanger (50) and the inflow side of the use side heat exchanger (35) in the heat transfer circuit (30). In addition to the first position, the heat transfer circuit (30) can be heated at the second position on the second passage (59) in the heat transfer circuit (30). While
The second heating means (71, 82) is constituted by a heat medium circuit through which a heat medium flows, and is connected to a solar heat collector (70) having a solar heat collector (76) for collecting solar heat, The heating medium of the heat transfer circuit (30) is heated by the heating medium heated by the solar heat collector (70),
The temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30) is detected, and the first temperature is detected when the detected temperature is higher than a predetermined reference temperature. The heating medium of the heat transfer circuit (30) is heated at the position, and when the detected temperature is equal to or lower than the reference temperature, the heating medium of the heat transfer circuit (30) is heated at the second position. A heating system comprising control means (55) for controlling the second heating means (71, 82) . In claim 1,
The control means (55) detects the temperature of the heat medium of the second heating means (71, 82) used for heating the heat medium of the heat transfer circuit (30), and the detected temperature is not more than a predetermined lower limit temperature. In this case, the heating system is configured to control the second heating means (71, 82) so as to stop the heating of the heat medium of the heat transfer circuit (30) . In claim 1 or 2,
The heating system characterized in that the second heating means (71, 82) is configured to heat the heat medium of the heat transfer circuit (30) using the exhaust heat of the power generation device (81). . In any one of Claims 1 thru | or 3,
The heat transfer circuit (30) includes a heat storage tank (37) for storing a heat medium heated by the first heating means (21) and the second heating means (71, 82). A normal operation of supplying only the heat medium heated by the heating means (21) and the second heating means (71, 82) to the use side heat exchanger (35); the first heating means (21) and the A heat storage operation for supplying the heat medium heated by the second heating means (71, 82) to both the use-side heat exchanger (35) and the heat storage tank (37), the first heating means (21), and The use operation of supplying both the heat medium heated by the second heating means (71, 82) and the heat medium in the heat storage tank (37) to the use side heat exchanger (35) is selectively performed. A heating system characterized by that.

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