JP7731322B2 - Air conditioning system - Google Patents

Description

The present invention relates to an air conditioning system. In particular, the present invention relates to preventing condensation on a box that houses a heat exchanger of an air conditioning system.

Conventionally, there is an air conditioning system that includes a heat pump heat source, a combustion heat source, an air conditioning device that heats and cools indoor spaces, a refrigerant circuit that circulates refrigerant between the heat pump heat source and a first heat exchanger, a heat medium circuit that circulates heat medium between the combustion heat source and a second heat exchanger, and a circulation path that circulates circulating fluid between the first and second heat exchangers and the air conditioning device (see, for example, Patent Document 1). In this air conditioning device, refrigerant is circulated between the heat pump heat source and the first heat exchanger, and the circulating fluid flowing through the circulation path is cooled by the first heat exchanger, thereby cooling the indoor space.

Japanese Patent Application Laid-Open No. 2020-159663

In air conditioning systems that connect multiple devices, such as heat sources and air conditioners, a heat exchanger unit containing a heat exchanger within a housing may be installed in the underfloor space. When the first and second heat exchangers are connected by a circulation path, as in Patent Document 1, cooled circulating fluid also flows into the second heat exchanger during cooling, lowering the internal temperature within the housing of the heat exchanger unit that houses the second heat exchanger. As a result, when the outside temperature is high in the summer and the exterior surface of the housing falls below the dew point, condensation occurs, causing the problem of mold growing in the underfloor space.

The present invention aims to solve the above problem, and its object is to prevent condensation from forming on the box housing the heat exchanger of an air conditioning system.

According to the present invention,
a first heat source capable of heating and cooling a first heat medium;
a second heat source capable of heating a second heat medium;
an air conditioner capable of selectively heating and cooling the indoor space by performing heat exchange between a first heat medium and the indoor space;
a first heat medium circuit that circulates a first heat medium between the first heat source and the air conditioning device;
a heat exchanger connected to a position downstream of the first heat source and upstream of the air conditioner in the first heat medium circuit;
a second heat medium circuit that circulates a second heat medium between the second heat source and the heat exchanger;
a circulation pump that circulates the second heat medium between the second heat source and the heat exchanger;
a bypass circuit connecting the first heat medium circuit upstream and downstream of the heat exchanger to bypass the heat exchanger;
a valve device that blocks the first heat medium circuit in the heat exchanger on at least one of the upstream side and the downstream side of the heat exchanger so that the first heat medium after circulating through the first heat source does not flow into the heat exchanger but flows into the bypass circuit;
a box that accommodates at least a portion of the heat exchanger and at least a portion of the bypass circuit;
a control device;
When the first heat medium is cooled by the first heat source and supplied to the air conditioning device, the control device operates the valve device so that the first heat medium that has circulated through the first heat source does not flow into the heat exchanger but instead flows through the bypass circuit, and also operates the circulation pump to circulate the second heat medium between the second heat source and the heat exchanger, thereby providing an air conditioning system.

In the above air conditioning system, when the first heat medium is cooled by the first heat source and supplied to the air conditioner, the valve device is operated so that the first heat medium that has circulated through the first heat source circulates through the bypass circuit without flowing into the heat exchanger, and the circulation pump is operated to circulate the second heat medium between the second heat source and the heat exchanger. This makes it possible to prevent a drop in the internal temperature inside the box that houses at least a portion of the heat exchanger and bypass circuit, even during cooling operation. This prevents condensation on the outer surface of the box in the summer.

Preferably, the air conditioning system further comprises:
a box internal temperature detection means for detecting an internal temperature of the box;
When the internal temperature of the box falls to or below a predetermined temperature, the control device operates the circulation pump to circulate the second heat medium between the second heat source and the heat exchanger.

With the above air conditioning system, the circulation pump is activated when the internal temperature inside the box drops below a predetermined temperature, thereby efficiently preventing condensation.

Preferably, in the air conditioning system,
The control device operates the circulation pump to circulate the second heat medium that is not heated by the second heat source between the second heat source and the heat exchanger.

The above air conditioning system circulates the second heat medium that is not heated by the second heat source, making it possible to prevent condensation with low energy consumption.

FIG. 1 is a schematic diagram showing an example of an air conditioning system according to an embodiment of the present invention. FIG. 2 is a block diagram showing an example of an air conditioning system according to an embodiment of the present invention. FIG. 3 is a diagram illustrating the operation of the air conditioning system according to the embodiment of the present invention. FIG. 4 is a diagram illustrating the operation of the air conditioning system according to the embodiment of the present invention.

An air conditioning system according to an embodiment of the present invention will be described below.
1, an air conditioning system 1 of this embodiment includes a cooling and heating air conditioner 3 as an air conditioning device, a heat pump unit 10 as a first heat source capable of heating and cooling a first heat medium, and a combustion heat source machine 20 as a second heat source capable of heating a second heat medium. The first and second heat mediums in this air conditioning system 1 may be, for example, water or antifreeze.

The cooling and heating air conditioning unit 3 has a flow path (not shown) through which a first heat medium flows, and is a known air conditioning unit that heats or cools an indoor space by exchanging heat between the first heat medium flowing through the flow path and the indoor space in which it is located, and is configured, for example, as a fan coil unit. In addition to the cooling and heating air conditioning unit, other heating devices (for example, heating devices such as fan convectors, panel radiators, and floor heating devices, or bathroom heating devices that heat, dry, and ventilate the bathroom) may also be installed.

The heat pump unit 10 includes a heat pump 11 of known configuration. The heat pump 11 includes a heat medium-side heat exchanger 12 and a refrigerant circuit 13 including a compressor, an outdoor air-side heat exchanger, and an expansion mechanism (not shown). The refrigerant circuit 13 is capable of circulating refrigerant from the outdoor air-side heat exchanger through the compressor, the heat medium-side heat exchanger 12, and the expansion mechanism in that order. In this state, heat absorbed by the refrigerant from the outdoor air via the outdoor air-side heat exchanger is dissipated via the heat medium-side heat exchanger 12 to a first heat medium flowing through a first heat medium circuit 40 (described below), thereby heating the first heat medium.

The refrigerant circuit 13 can also circulate the refrigerant from the heat medium side heat exchanger 12 through the compressor, outdoor air side heat exchanger, and expansion mechanism in that order. In this state, the heat absorbed by the refrigerant from the first heat medium flowing through the first heat medium circuit 40 (described below) via the heat medium side heat exchanger 12 can be released to the outdoor air via the outdoor air side heat exchanger, thereby cooling the first heat medium. Therefore, the heat pump unit 10 functions as a heat source capable of heating and cooling the first heat medium.

The combustion heat source unit 20 is equipped with a heating unit 21 that heats the second heat medium. The heating unit 21 is composed of a burner 22 and a heat exchanger 23 that is heated by the heat of combustion of the burner 22. The burner 22 is, for example, a gas burner, and is supplied with fuel gas from a fuel supply source (not shown) via a fuel supply line 24, and combustion air is supplied by the operation of a combustion fan (not shown). The fuel supply line 24 is fitted with an on-off valve 25 that can open and close the fuel supply line 24, and a fuel adjustment valve 26 that adjusts the amount of fuel gas supplied to the burner 22. The on-off valve 25 may be composed of a solenoid valve or the like, and the fuel adjustment valve 26 may be composed of a proportional valve or the like.

The burner 22 begins combustion operation by activating the combustion fan and igniting it with an ignition device (not shown) while the on-off valve 25 is controlled to be open. During combustion operation of the burner 22, the amount of combustion by the burner 22 can be controlled by controlling the fuel adjustment valve 26 and the combustion fan. Furthermore, the burner 22 is extinguished by controlling the on-off valve 25 to be closed. The fuel for the burner 22 is not limited to gaseous fuel, and may be liquid fuel such as kerosene.

The heat exchanger 23 of the heating unit 21 is connected to the second heat medium circuit 50 (described below) so that the second heat medium flows through the second heat medium circuit 50, and is configured to heat the second heat medium by radiating the combustion heat provided by the combustion operation of the burner 22 to the second heat medium. The heating unit 21 may also be equipped with a bypass path that allows the second heat medium to flow from the upstream side to the downstream side of the heat exchanger 23 without passing through the heat exchanger 23, or a control valve for adjusting the ratio between the flow rate of the second heat medium passing through the bypass path and the flow rate of the second heat medium passing through the heat exchanger 23.

The air conditioning system 1 further includes a heat exchanger unit 30 including a liquid-liquid heat exchanger 31 that exchanges heat between a first heat medium heated by the heat pump 11 and a second heat medium heated by the heating section 21; a first heat medium circuit 40 that connects the heat medium-side heat exchanger 12 of the heat pump 11 to the air conditioning unit 3 for heating and cooling so that the first heat medium can circulate between them; a second heat medium circuit 50 that connects the heat exchanger 23 of the combustion heat source unit 20 to the heat exchanger 31 of the heat exchanger unit 30 so that the second heat medium can circulate between them; and a bypass circuit 41e that connects the upstream and downstream sides of the first heat medium circuit 40 of the heat exchanger 31, bypassing the heat exchanger 31.

The heat exchanger unit 30 has a box 300 that houses the heat exchanger 31, bypass circuit 41e, and other components. The heat exchanger 31 of the heat exchanger unit 30 is configured to perform heat exchange between a first flow path 31a, through which a first heat medium heated by the heat pump 11 flows, and a second flow path 31b, through which a second heat medium heated by the heating section 21 flows. Therefore, the heat exchanger 31 is connected to the first heat medium circuit 40 downstream of the heat medium-side heat exchanger 12 of the heat pump 11 and upstream of the heating and cooling air conditioner 3. The first flow path 31a in the heat exchanger 31 forms part of the first heat medium circuit 40, and the second flow path 31b in the heat exchanger 31 forms part of the second heat medium circuit 50.

The first heat medium circuit 40 has an outgoing path 41 that supplies the first heat medium from the heat medium-side heat exchanger 12 of the heat pump 11 to the air conditioning unit 3 for heating and cooling, and a returning path 42 that returns the first heat medium from the air conditioning unit 3 for heating and cooling to the heat medium-side heat exchanger 12. The outgoing path 41 is provided with the first flow path 31a of the heat exchanger 31 of the heat exchanger unit 30, and a bypass circuit 41e that branches off from the upstream side of the first flow path 31a to the downstream side, allowing the first heat medium to flow without passing through the first flow path 31a.

Specifically, the outgoing path 41 of the first heat transfer medium circuit 40 includes a first outgoing path 41a that connects the heat transfer medium outlet of the heat transfer medium-side heat exchanger 12 of the heat pump 11 to the heat transfer medium inlet of the first flow path 31a of the heat exchanger 31, and a second outgoing path 41b whose upstream end is connected to the heat transfer medium outlet of the first flow path 31a of the heat exchanger 31 and whose downstream end is connected to the heat transfer medium inlet of the air conditioning unit 3 for heating and cooling. The bypass circuit 41e branches off from the middle of the first outgoing path 41a and merges with the middle of the second outgoing path 41b so as to be connected to the outgoing path 41 of the first heat transfer medium circuit 40 in parallel with the first flow path 31a of the heat exchanger 31. Note that while FIG. 1 shows the heat exchanger 31 and bypass circuit 41e entirely housed within the box 300, at least a portion of these may be housed within the box 300 depending on the installation location.

The return path 42 of the first heat transfer medium circuit 40 has its upstream end connected to the heat transfer medium outlet of the air conditioning unit 3 for heating and cooling, and its downstream end connected to the heat transfer medium inlet of the heat transfer medium-side heat exchanger 12 of the heat pump 11.

An electric pump 43 serving as a power source for circulating the heat medium is attached to the first outgoing line 41a upstream of the connection between the first outgoing line 41a and the bypass circuit 41e. In this embodiment, the pump 43 is mounted on the heat pump unit 10. However, the pump 43 may also be mounted on the heat exchanger unit 30, for example, or may be located external to the heat pump unit 10 and the heat exchanger unit 30. The pump 43 may also be attached to the second outgoing line 41b downstream of the connection between the second outgoing line 41b and the bypass circuit 41e, or to the return line 42, for example.

An electrically operated three-way valve 44 is installed at the connection between the first outflow path 41a and the bypass circuit 41e. The three-way valve 44 can be switched between two operating states: one in which the first heat medium flows from the upstream first outflow path 41a only through the first flow path 31a of the heat exchanger 31 and the bypass circuit 41e is blocked (one in which the first flow path 31a of the heat exchanger 31 is open to the upstream first outflow path 41a of the three-way valve 44 and the bypass circuit 41e is blocked), and one in which the first heat medium flows from the upstream first outflow path 41a only through the bypass circuit 41e and the first flow path 31a of the heat exchanger 31 is blocked (one in which the upstream first outflow path 41a of the three-way valve 44 is closed to the upstream first outflow path 41a of the three-way valve 44 and the bypass circuit 41e is opened).

The three-way valve 44 may be configured to adjust the ratio between the flow rate of the first heat medium flowing through the first flow path 31a of the heat exchanger 31 and the flow rate of the first heat medium flowing through the bypass circuit 41e to a desired target ratio (including the case where the flow rate through the first flow path 31a is set to zero and the case where the flow rate through the bypass circuit 41e is set to zero).

In this embodiment, the three-way valve 44 is mounted on the heat exchanger unit 30. However, the three-way valve 44 may also be disposed external to the heat exchanger unit 30. The three-way valve 44 may also be attached to the connection between the second outward path 41b and the bypass circuit 41e. Instead of the three-way valve 44, an open/close valve or flow control valve may be provided in each of the bypass circuit 41e and the flow path that passes through the first flow path 31a of the heat exchanger 31 from the connection between the first outward path 41a and the bypass circuit 41e to the connection between the second outward path 41b and the bypass circuit 41e.

A thermal valve 46 is installed in the second outward path 41b, which is connected to the cooling and heating air conditioner 3. The thermal valve 46 may be installed in the return path 42, or may be mounted on the cooling and heating air conditioner 3.

Since the first heat medium circuit 40 is configured as described above, when the pump 43 is operated with the thermal valve 46 open, the first heat medium flows back from the heat medium-side heat exchanger 12 of the heat pump 11 via the outward path 41, the air conditioning unit 3, and the return path 42, in that order, to the heat medium-side heat exchanger 12, thereby circulating the first heat medium between the heat medium-side heat exchanger 12 and the air conditioning unit 3. In this case, by controlling the operation of the three-way valve 44, the first heat medium can be circulated through either (or both) the first flow path 31a and the bypass circuit 41e of the heat exchanger 31.

The second heat medium circuit 50 includes an outward path 51 that supplies the second heat medium from the heat exchanger 23 of the heating section 21 of the combustion heat source unit 20 to the second flow path 31b of the heat exchanger 31 of the heat exchanger unit 30, and a return path 52 that returns the heat medium from the second flow path 31b of the heat exchanger 31 to the heat exchanger 23 of the heating section 21.

The outgoing path 51 is arranged to connect the heat medium outlet of the heat exchanger 23 of the heating section 21 to the heat medium inlet of the second flow path 31b of the heat exchanger 31 of the heat exchanger unit 30, and the returning path 52 is arranged to connect the heat medium outlet of the second flow path 31b of the heat exchanger 31 of the heat exchanger unit 30 to the heat medium inlet of the heat exchanger 23 of the heating section 21. A circulation pump 53 is installed in the returning path 52 as a power source for circulating the second heat medium.

In this embodiment, the circulation pump 53 is mounted on the combustion heat source unit 20. However, the circulation pump 53 may also be located outside the combustion heat source unit 20, or may be attached to the outgoing path 51.

Since the second heat medium circuit 50 is configured as described above, when the circulation pump 53 is operated, the second heat medium flows back from the heat exchanger 23 of the heating unit 21 via the outward path 51, the second flow path 31b of the heat exchanger 31, and the return path 52 in that order to the heat exchanger 23 of the heating unit 21, thereby circulating the second heat medium between the heat exchanger 23 of the heating unit 21 and the heat exchanger 31 of the heat exchanger unit 30.

As shown in FIG. 2, the air conditioning system 1 includes a control device 80 that controls the operation of the air conditioning system 1, and a remote control 85 that allows the user to operate the air conditioning system 1. The control device 80 is composed of one or more electronic circuit units, including, for example, a processor such as a microcomputer (not shown), memory (RAM, ROM, etc.), an interface circuit, a communication circuit, etc.

For example, the control device 80 may be configured as a collection of multiple electronic circuit units that are mounted on each of the heating and cooling air conditioners 3, the heat pump unit 10, the combustion heat source unit 20, and the heat exchanger unit 30, and that communicate with each other and work together to control the operation of the air conditioning system 1.

The control device 80 receives input of sensing signals (detection signals) from a plurality of sensors, such as a plurality of temperature sensors 90, provided in the air conditioning system 1. In this embodiment, the temperature sensors 90 include, for example, a temperature sensor 90a that detects the temperature of the first heat medium (the temperature of the first heat medium flowing out of the heat medium-side heat exchanger 12) flowing from the heat pump 11's heat medium-side heat exchanger 12 through the outgoing line 41 (first outgoing line 41a) of the first heat medium circuit 40 into the three-way valve 44, a temperature sensor 90b that detects the temperature of the first heat medium supplied to the cooling and heating air conditioner 3 through the outgoing line 41 (second outgoing line 41b) downstream of the first flow path 31a of the heat exchanger 31 and the bypass circuit 41e, and a temperature sensor 90c that detects the temperature of the first heat medium flowing out of the heat medium-side heat exchanger 12. These include a temperature sensor 90c that detects the temperature of the second heat medium flowing from the heat exchanger 23 into the outward path 51 of the second heat medium circuit 50, a temperature sensor 90d that detects the temperature of the second heat medium flowing from the outward path 51 into the second flow path 31b of the heat exchanger 31, a temperature sensor 90e that detects the temperature of the second heat medium flowing from the second flow path 31b of the heat exchanger 31 into the return path 52 of the second heat medium circuit 50, and an internal box temperature sensor (internal box temperature detection means) 90f that is provided near the bottom surface of the box 300 of the heat exchanger unit 30 and detects the internal temperature within the box 300.

The control device 80 is also capable of wired or wireless communication with the remote control 85. Through this communication, the control device 80 can receive command information related to the operation of the cooling and heating air conditioner 3 from the remote control 85, and can also send and output various notification information to the remote control 85.

The control device 80 has the function of executing control processes related to the operation of the cooling and heating air conditioner 3, as a function realized by the implemented hardware configuration and program (software configuration). In this case, the control device 80 is able to control the operation of the heat pump 11, the burner 22 of the heating unit 21, the three-way valve 44, the thermal valve 46, and the pumps 43 and 53, which are the elements to be controlled, and controls the operation of the cooling and heating air conditioner 3 through this operation control.

Operation control of the heat pump 11 involves switching between heating and cooling the first heat medium and controlling the output of the heat pump 11 by controlling the switching of the flow path of the refrigerant circuit 13 and the operation of the compressor. Furthermore, operation control of the burner 22 involves controlling the operation of the on-off valve 25 and fuel adjustment valve 26 of the fuel supply line 24, as well as the ignition device and combustion fan (not shown), thereby igniting the burner 22, adjusting the combustion amount, and extinguishing the burner 22.

Next, with reference to Figures 3 and 4, the operation of the cooling and heating air conditioner 3 in the air conditioning system 1 of this embodiment during cooling operation will be described. Note that in these figures, thick solid lines indicate flow paths when the heat medium is flowing, and thin dashed lines indicate flow paths when the heat medium is not flowing.

When the cooling/heating air conditioner 3 is in cooling operation, the control device 80 operates the heat pump 11 in cooling operation mode (an operation mode in which the refrigerant circuit 13 is operated to flow cooled refrigerant through the heat medium-side heat exchanger 12) and operates the pump 43 with the thermal valve 46 open. The control device 80 also operates the three-way valve 44 of the first heat medium circuit 40 so that the first heat medium flows only through the bypass circuit 41e of the first flow path 31a and bypass circuit 41e of the heat exchanger 31 of the heat exchanger unit 30.

As a result, as shown in FIG. 3, the first heat medium circulates between the heat pump 11's heat medium-side heat exchanger 12 and the cooling and heating air conditioner 3 via the bypass circuit 41e without passing through the first flow path 31b of the heat exchanger 31, and the first heat medium cooled in the heat medium-side heat exchanger 12 is supplied to the cooling and heating air conditioner 3, thereby performing cooling operation of the cooling and heating air conditioner 3 (heat absorption operation from the indoor space by the cooling and heating air conditioner 3).

During cooling operation, the control device 80 monitors the internal temperature output from the internal temperature sensor 90f. When the internal temperature falls below a predetermined temperature (e.g., 26°C or below, assuming worst-case conditions of an outside temperature of 30°C and humidity of 80%), the control device 80 activates the circulation pump 53. As a result, as shown in FIG. 4, the second heat medium circulates through the second heat medium circuit 50 between the heating section 21 and the heat exchanger 31 of the heat exchanger unit 30 via the second flow path 31b of the heat exchanger 31. The temperature of the unheated second heat medium is approximately room temperature, which is higher than the temperature of the first heat medium after circulating through the heat medium-side heat exchanger 12 of the heat pump 11. Therefore, by circulating the second heat medium through the second flow path 31b of the heat exchanger 31, the temperature of the heat exchanger 31 can be raised, thereby preventing a decrease in the internal temperature of the box 300. This prevents condensation. If the internal temperature of the box 300 exceeds a predetermined temperature, the circulation pump 53 may be stopped to stop the circulation of the second heat medium. Furthermore, if the internal temperature of the box 300 remains below the predetermined temperature even after circulating the room-temperature second heat medium through the heat exchanger 31 for a predetermined time or longer, the burner 22 of the heating section 21 of the combustion heat source unit 20 may continue combustion operation until the internal temperature of the box 300 exceeds the predetermined temperature.

As explained in detail above, according to this embodiment, even when the heat pump 11 cools the first heat medium and supplies it to the air conditioning unit 3, it is possible to prevent a decrease in the internal temperature within the box 300 that houses the heat exchanger 31 and bypass circuit 41e. Therefore, during cooling operation in the summer, the temperature of the outer surface of the box 300 can be prevented from falling below the condensation temperature, thereby preventing condensation.

Furthermore, according to this embodiment, the circulation pump 53 is operated to circulate the unheated second heat medium through the heat exchanger 31 only when the internal temperature of the box 300 falls below a predetermined temperature, thereby preventing condensation efficiently and with low energy consumption.

In addition, in this embodiment, the second heat medium at room temperature is supplied to the heat exchanger 31 during cooling operation, but the first heat medium does not flow through the heat exchanger 31, preventing the cooled first heat medium from absorbing heat in the heat exchanger 31. This reduces energy loss during cooling operation.

To briefly explain the operation of the cooling and heating air conditioner 3 in the air conditioning system 1 of this embodiment during heating operation, when the cooling and heating air conditioner 3 is in heating operation, the control device 80 first operates the heat pump 11 in a heating operation mode (an operation mode in which the refrigerant circuit 13 is operated to flow heated refrigerant through the heat medium side heat exchanger 12), and also operates the pump 43 with the thermal valve 46 open.

As a result, the first heat medium circulates between the heat pump 11's heat medium-side heat exchanger 12 and the cooling and heating air conditioner 3 via the first heat medium circuit 40, and the first heat medium heated by the heat medium-side heat exchanger 12 is supplied to the cooling and heating air conditioner 3, thereby performing heating operation of the cooling and heating air conditioner 3 (heat dissipation operation from the cooling and heating air conditioner 3 to the indoor space).

At this time, if the temperature of the first heat medium supplied to the air conditioning unit 3 for heating and cooling can be raised to the target temperature by operating the heat pump 11 alone, the control device 80 operates the three-way valve 44 of the first heat medium circuit 40 so that the first heat medium flows only through the bypass circuit 41e of the first flow path 31a and bypass circuit 41e of the heat exchanger 31 of the heat exchanger unit 30.

Furthermore, if the temperature of the first heat medium supplied to the air conditioning unit 3 cannot be raised to the target temperature even when the heat pump 11 is operated at its upper limit output, the control device 80 not only operates the heat pump 11 and the pump 43, but also operates the circulation pump 53 while starting combustion operation of the burner 22 of the heating section 21 of the combustion heat source unit 20, and further operates the three-way valve 44 so that the first heat medium flows only through the first flow path 31a of the first flow path 31a and the bypass circuit 41e of the heat exchanger 31 of the heat exchanger unit 30, or through both the first flow path 31a and the bypass circuit 41e.

As a result, the first heat medium supplied to the cooling and heating air conditioner 3 is not only heated in the heat medium-side heat exchanger 12 of the heat pump 11, but also heated by heat exchange with the second heat medium (second heat medium heated in the heat exchanger 23 of the heating unit 21) flowing through the second flow path 31b of the heat exchanger 31 as it flows through the first flow path 31a of the heat exchanger 31. This reduces energy loss during heating operation.

(Other embodiments)
In the above embodiment, when the internal temperature of the box 300 falls below a predetermined temperature, the circulation pump 53 is operated to circulate the second heat medium to the heat exchanger 31. However, during cooling operation, the circulation pump 53 may be operated to circulate the second heat medium to the heat exchanger 31 even if the internal temperature of the box 300 is higher than the predetermined temperature.

REFERENCE SIGNS LIST 1 Air conditioning system 3 Air conditioning device for heating and cooling 10 Heat pump unit 20 Combustion type heat source device 31 Heat exchanger 40 First heat medium circuit 41e Bypass circuit 44 Three-way valve 50 Second heat medium circuit 53 Circulation pump 80 Control device 300 Box body

Claims (3)

a first heat source capable of heating and cooling a first heat medium;
a second heat source capable of heating a second heat medium;
an air conditioner capable of selectively heating and cooling the indoor space by performing heat exchange between a first heat medium and the indoor space;
a first heat medium circuit that circulates a first heat medium between the first heat source and the air conditioning device;
a heat exchanger connected to a position downstream of the first heat source and upstream of the air conditioner in the first heat medium circuit;
a second heat medium circuit that circulates a second heat medium between the second heat source and the heat exchanger;
a circulation pump that circulates the second heat medium between the second heat source and the heat exchanger;
a bypass circuit connecting the first heat medium circuit upstream and downstream of the heat exchanger to bypass the heat exchanger;
a valve device that blocks the first heat medium circuit in the heat exchanger on at least one of the upstream side and the downstream side of the heat exchanger so that the first heat medium after circulating through the first heat source does not flow into the heat exchanger but flows into the bypass circuit;
a box that accommodates at least a portion of the heat exchanger and at least a portion of the bypass circuit;
a control device;
When the first heat medium is cooled by the first heat source and supplied to the air conditioning device, the control device operates the valve device so that the first heat medium that has circulated through the first heat source does not flow into the heat exchanger but instead flows through a bypass circuit, and also operates the circulation pump to circulate the second heat medium between the second heat source and the heat exchanger. The air conditioning system according to claim 1 further comprises:
a box internal temperature detection means for detecting an internal temperature of the box;
The control device is an air conditioning system in which, when the internal temperature of the box falls below a predetermined temperature, the control device activates a circulation pump to circulate a second heat medium between the second heat source and the heat exchanger. 3. The air conditioning system according to claim 1,
The control device operates a circulation pump to circulate a second heat medium that is not heated by the second heat source between the second heat source and the heat exchanger.