JP2016102636A - Air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning system showing a superior efficiency including a heat source device utilizing geothermal heat, a heat source device using electricity or fuel and an air conditioner device performing an air conditioning under utilization of heat of circulating fluid cooled/heated by these heat source devices.SOLUTION: An air conditioning system 100 comprises a geothermal heat exchanger device 60 for cooling/heating circulating fluid at a geothermal heat exchanger 61 utilizing geothermal heat, a cooling tower 80 for cooling/heating circulating fluid and a boiler 90, an air conditioner device 30 and a controller 70. The controller selectively executes the first control mode in which the air conditioner device performs an air conditioning operation under utilization of heat from the circulating fluid cooled/heated by the geothermal heat exchanger and the second control mode in which the air conditioner device performs an air conditioning operation under utilization of heat of the circulating fluid cooled/heated by the cooling tower or the boiler. Under the second control mode, when surplus heat more than requisite amount of heat required for the air conditioner device to perform air conditioning operation, heat of the circulating fluid is given to the geothermal heat exchanger device.SELECTED DRAWING: Figure 1

Description

  The present invention uses an air conditioning system, more specifically, a heat source device that uses underground heat, a heat source device that uses electricity or fuel, and the heat of a circulating fluid cooled / heated by these heat source devices. And an air conditioning system equipped with an air conditioning system.

  Conventionally, an air conditioning system that uses geothermal heat as a heat source has been known as disclosed in Japanese Patent Application Laid-Open No. 2012-047360. The underground temperature is easily maintained constant regardless of the season, and an efficient air conditioning system can be realized as compared with the case where air is used as a heat source.

  However, since the underground heat is not inexhaustible, for example, if the underground heat is excessively used for heating in winter, the underground temperature gradually decreases, and the capacity of the air conditioning system may decrease.

  In order to continue heating even in such a case, it is conceivable to provide a boiler as a backup heat source. However, since the capacity of the installed boiler is determined so that the capacity is not insufficient even at the peak load, the boiler repeatedly starts and stops at the partial load, and the efficiency may decrease.

  An object of the present invention is to provide a heat source device that uses underground heat, a heat source device that uses electricity or fuel, and an air conditioner that performs air conditioning using the heat of a circulating fluid cooled / heated by these heat source devices. The present invention is to provide an air conditioning system having excellent efficiency.

  An air conditioning system according to a first aspect of the present invention includes a first heat source device, a second heat source device different from the first heat source device, an air conditioner, and a control unit. The first heat source device has an underground heat exchanger, and cools or heats the circulating fluid in the underground heat exchanger using the underground heat. The second heat source device cools or heats the circulating fluid using electricity or fuel. The air conditioner performs air conditioning using the heat of the circulating fluid. The control unit selectively executes the first control mode and the second control mode. In the first control mode, the air conditioner is caused to perform air conditioning using the heat of the circulating fluid cooled or heated by the first heat source device without using the second heat source device. In the second control mode, the air conditioner is caused to perform air conditioning using the heat of the circulating fluid cooled or heated by the second heat source device without using the first heat source device. In the second control mode, the control unit also supplies the heat of the circulating fluid to the underground heat exchanger when excessive heat necessary for the air conditioner to perform air conditioning is generated.

  In the air conditioning system according to the first aspect of the present invention, the second heat source device cools or heats the circulating fluid using electricity or fuel, and the excess heat is more than necessary for the air conditioning device to perform air conditioning. When this occurs, the heat of the circulating fluid is also supplied to the underground heat exchanger. Therefore, surplus heat can be utilized without waste for recovery of underground heat. Therefore, an air conditioning system with excellent efficiency can be realized without wasting excess heat.

  The air conditioning system which concerns on the 2nd viewpoint of this invention is an air conditioning system which concerns on a 1st viewpoint, Comprising: A control part performs 1st control mode at the time of the driving | operation start of the said air conditioning system. The control unit starts the second control mode instead of the first control mode when the underground temperature drops below the first temperature during execution of the first control mode. The controller starts the first control mode instead of the second control mode when the underground temperature rises above the second temperature higher than the first temperature during execution of the second control mode.

  In the air conditioning system according to the second aspect of the present invention, even when the air conditioner is in the heating operation and the underground temperature decreases, the air conditioner is executed by executing the second control mode instead of the first control mode. Can be operated efficiently. On the other hand, when the underground temperature recovers, the efficient air-conditioning heating operation using the underground heat can be performed by switching from the second control mode to the first control mode.

  The air conditioning system which concerns on the 3rd viewpoint of this invention is an air conditioning system which concerns on a 1st viewpoint or a 2nd viewpoint, Comprising: In a 2nd control mode, when a stop of the 2nd heat-source apparatus by a capability excess generate | occur | produces a control part In addition, the heat of the circulating fluid is supplied to the underground heat exchanger because surplus heat is generated.

  In the air conditioning system according to the third aspect of the present invention, it is possible to prevent a situation in which the second heat source device repeatedly starts / stops in the second control mode, and the second heat source device can be operated efficiently.

  In the air conditioning system according to the first aspect, the circulating fluid is cooled or heated using electricity or fuel by the second heat source device, and excess heat is generated that is more than necessary for the air conditioning device to perform air conditioning. In addition, heat from the circulating fluid is also supplied to the underground heat exchanger. Therefore, surplus heat can be utilized without waste for recovery of underground heat. Therefore, an air conditioning system with excellent efficiency can be realized without wasting excess heat.

  In the air conditioning system according to the second aspect, the air conditioner can be operated efficiently even when the underground temperature decreases during the heating operation of the air conditioner, and when the underground temperature recovers, the efficiency using the underground heat is good. The heating operation of the air conditioner can be performed.

  In the air conditioning system according to the third aspect, it is possible to prevent a situation in which the second heat source device repeats starting / stopping in the second control mode, and to efficiently operate the second heat source device.

It is a schematic structure figure of an air-conditioning system concerning one embodiment of the present invention. It is a schematic block diagram of the air conditioner which the air conditioning system of FIG. 1 has. It is a flowchart explaining the selection process of the control mode performed at the time of the heating operation of an air conditioner in the air conditioning system of FIG. It is a figure explaining the flow of the circulating fluid at the time of 1st control mode execution in the air conditioning system of FIG. It is a figure explaining the flow of the circulating fluid at the time of 2nd control mode execution in the air conditioning system of FIG. 1 (at the time of heating operation of an air conditioner). In addition, in FIG. 5, the flow of the circulating fluid in the state where the underground heat storage control mode is not executed is drawn. It is a figure explaining the flow of the circulating fluid at the time of execution of 2nd control mode and underground heat storage control mode in the air conditioning system of FIG. 1 (at the time of heating operation of an air conditioner). It is a flowchart explaining the selection process of the control mode performed at the time of the air_conditioning | cooling operation of the air conditioner in the air conditioning system of FIG.

  An air conditioning system 100 according to an embodiment of the present invention will be described with reference to the drawings.

  The following embodiments are merely examples, and can be appropriately changed without departing from the gist of the present invention.

(1) Overall Configuration The air conditioning system 100 according to the present embodiment is an air conditioning system installed in a building or the like. The air conditioning system 100 is used for cooling and heating of a building or the like in which the air conditioning system 100 is installed. However, the present invention is not limited to this, and the air conditioning system 100 may be used only for cooling or heating of a building or the like in which the air conditioning system 100 is installed.

  The air conditioning system 100 mainly includes a pipe 21, a ground heat exchanger 60, a cooling tower 80, a boiler 90, a first pump 62, a second pump 20, an air conditioner 30, and a controller 70 (see FIG. 1). In FIG. 1, the number of air conditioners 30 is three, but the number of air conditioners 30 is not limited to this, and may be one, or two or four or more. There may be.

  The underground heat exchange device 60 is an example of a first heat source device. The underground heat exchange device 60 has an underground heat exchanger 61 installed in the ground. When the first pump 62 described later is operated, the circulating fluid flows through the underground heat exchanger 61, and the circulating fluid is cooled or heated using the underground heat in the underground heat exchanger 61. . When the second pump 20 described later is operated, the circulating fluid flows through the underground heat exchanger 61, and the heat of the circulating fluid (including both cold / hot) is supplied to the underground heat exchanger 61. The ground is cooled or heated.

  The cooling tower 80 and the boiler 90 are an example of a second heat source device. The cooling tower 80 and the boiler 90 cool or heat the circulating fluid circulated by the second pump 20 using electricity or fuel. The cooling tower 80 is installed on the rooftop of a building or the like where the air conditioning system 100 is installed, for example. In the cooling tower 80, the circulating fluid is cooled to a predetermined temperature. The boiler 90 is installed in a machine room such as a building where the air conditioning system 100 is installed, for example. In the boiler 90, the circulating fluid is heated to a predetermined temperature.

  The piping 21 is a heat source device 40 of the air conditioner 30 to be described later using a circulating fluid cooled or heated by the underground heat exchange device 60, a circulating fluid cooled by the cooling tower 80, or a circulating fluid heated by the boiler 90. It is piping for carrying up to. The pipe 21 is provided with a first pump 62 and a second pump 20. The first pump 62 circulates the circulating fluid in a fluid circuit including the underground heat exchange device 60, the pipe 21, and the heat source device 40 of the air conditioner 30. The second pump 20 circulates the circulating fluid in a fluid circuit including the cooling tower 80 or the boiler 90, the pipe 21, and the heat source unit 40 of the air conditioner 30. In addition, when the underground heat storage control mode to be described later is executed, the second pump 20 supplies the circulating fluid in a fluid circuit including the underground heat exchange device 60, the cooling tower 80 or the boiler 90, and the pipe 21. Circulate.

  Here, brine is used as the circulating fluid, but the present invention is not limited to this. For example, instead of brine, water may be used as the circulating fluid.

  Each air conditioner 30 includes a heat source device 40, a plurality of indoor units 50, and a flow rate adjustment valve 35 (see FIG. 1). The heat source device 40 is installed, for example, in a machine room on each floor such as a building where the air conditioning system 100 is installed. The indoor unit 50 is installed in an air-conditioning target space to be air-conditioned. As will be described later, the heat source unit 40 and the indoor unit 50 are connected by a refrigerant pipe to form a refrigerant circuit 31 (see FIG. 2). In the air conditioner 30, the refrigerant flows through the refrigerant circuit 31, and the vapor compression refrigeration cycle is performed, whereby the air-conditioning target space is cooled or heated. The heat source device 40 is connected to the pipe 21. In the heat source unit 40, heat exchange is performed between the refrigerant flowing through the refrigerant circuit 31 and the circulating fluid flowing through the pipe 21 to the heat source unit 40, and the refrigerant is cooled or heated by the circulating fluid. The flow rate adjustment valve 35 is provided in the pipe 21. The flow rate adjustment valve 35 is provided corresponding to the heat source device 40 and adjusts the amount of circulating fluid flowing through the heat source device 40.

  The controller 70 mainly includes a cooling tower 80, a boiler 90, a first pump 62, a second pump 20, and a plurality of valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, which are provided in a pipe 21 described later. 26b is controlled.

(2) Detailed Configuration The piping 21, the first pump 62, the second pump 20, the underground heat exchange device 60, the air conditioner 30, and the controller 70 will be described in detail.

(2-1) Piping The piping 21 is connected to the underground heat exchange device 60 (see FIG. 1). The pipe 21 is connected to the cooling tower 80 and the boiler 90 (see FIG. 1). Moreover, the piping 21 is connected with the heat-source equipment 40 which each of the some air conditioner 30 has (refer FIG. 1). More specifically, the pipe 21 is connected to the heat source side heat exchanger 43 of each heat source unit 40 so that the circulating fluid passes through the heat source side heat exchanger 43 of each heat source unit 40 (see FIG. 2). ).

  The pipe 21 is provided with a first pump 62 for carrying the circulating fluid cooled or heated in the underground heat exchange device 60 to the heat source unit 40 (see FIG. 1). The pipe 21 is provided with a second pump 20 for transporting the circulating fluid cooled by the cooling tower 80 or the circulating fluid heated by the boiler 90 to the heat source unit 40 (see FIG. 1). .

  The pipe 21 is provided with a plurality of valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, and 26b used to control the flow direction of the circulating fluid (see FIG. 1).

  The valves 23a and 23b are opened when the first pump 62 is in operation. When the valves 23a and 23b are opened and the first pump 62 is operated, the circulating fluid cooled or heated in the underground heat exchange device 60 flows into the heat source unit 40 and returns to the underground heat exchange device 60 again.

  The valves 24 a and 24 b are opened when the boiler 90 is in operation. When the valves 24a and 24b are opened and the second pump 20 is operated, the circulating fluid heated in the boiler 90 flows into the heat source unit 40 and returns to the boiler 90 again.

  The valves 25a and 25b are opened when the cooling tower 80 is in operation. When the valves 25a and 25b are opened and the second pump 20 is operated, the circulating fluid cooled in the cooling tower 80 flows into the heat source unit 40 and returns to the cooling tower 80 again.

  The valves 26a and 26b are opened when an underground heat storage control mode described later is executed. When the valves 26a and 26b are opened and the second pump 20 is operated, a part of the circulating fluid cooled by the cooling tower 80 or a part of the circulating fluid heated in the boiler 90 is converted into geothermal heat. It flows into the underground heat exchanger 61 of the exchange device 60 and returns to the cooling tower 80 or the boiler 90 again.

  Moreover, the flow rate adjustment valve 35 which each air conditioner 30 has is provided in the piping 21 in the upstream of the circulation fluid inlet_port | entrance of each heat-source equipment 40 (refer FIG. 1).

(2-2) 1st pump The 1st pump 62 is provided in the piping 21, and in the fluid circuit comprised by the underground heat exchange apparatus 60, the piping 21, and the heat source unit 40 of the air conditioner 30, Circulate the circulating fluid. The first pump 62 functions to carry the circulating fluid cooled or heated by the underground heat exchanger 61 of the underground heat exchange device 60 to the heat source unit 40 and return it to the underground heat exchange device 60 again.

(2-3) 2nd pump The 2nd pump 20 is provided in the piping 21, and in the fluid circuit comprised by the cooling tower 80 or the boiler 90, the piping 21, and the heat-source equipment 40 of the air conditioner 30, Circulate the circulating fluid. The second pump 20 carries the circulating fluid cooled by the cooling tower 80 to the heat source unit 40 and returns it to the cooling tower 80 again, or carries the circulating fluid heated by the boiler 90 to the heat source unit 40 and again the boiler. Function to return to 90.

  The second pump 20 is a fluid constituted by the underground heat exchanger 61 of the underground heat exchange device 60, the cooling tower 80 or the boiler 90, and the pipe 21 when the underground heat storage control mode described later is executed. Circulating fluid is also circulated in the circuit. That is, when the underground heat storage control mode is executed, the second pump 20 carries a part of the circulating fluid cooled by the cooling tower 80 to the underground heat exchanger 61 and returns it to the cooling tower 80 again, or a boiler. It functions to carry part of the circulating fluid heated at 90 to the underground heat exchanger 61 and return it to the boiler 90 again. The second pump 20 is also heated by the boiler 90 so that the circulating fluid cooled by the cooling tower 80 is transported to the heat source unit 40 and returned to the cooling tower 80 again when the underground heat storage control mode is executed. It functions to carry the circulating fluid to the heat source unit 40 and return it to the boiler 90 again.

(2-4) Ground Heat Exchange Device The ground heat exchange device 60 is a device that mainly collects underground heat. As shown in FIG. 2, the underground heat exchange device 60 includes an underground heat exchanger 61 embedded in the ground. The underground heat exchange device 60 includes a temperature sensor 63 that is provided in the piping 21 on the outlet side of the underground heat exchanger 61 and measures the temperature of the circulating fluid. The temperature sensor 63 is a sensor that measures the temperature of the circulating fluid after being sent to the underground heat exchanger 61 by the first pump 62 or the second pump 20 and passing through the underground heat exchanger 61.

  The underground heat exchange device 60 functions as a heat source device when the circulating fluid is sent to the underground heat exchanger 61 by the first pump 62 (when a first control mode described later is executed). That is, when the first pump 62 is in operation, the ground fluid exchanger 61 of the underground heat exchange device 60 uses the underground heat to cool or heat the circulating fluid, and the heat of the circulating fluid. The air conditioner 30 performs air conditioning using

  On the other hand, the underground heat exchange device 60 does not function as a heat source device when the circulating fluid is sent to the underground heat exchanger 61 by the second pump 20 (when the underground heat storage control mode described later is executed). . Specifically, when the underground heat storage control mode is being executed and the cold source (cooled circulating fluid) is required in the heat source unit 40 of the air conditioner 30, the underground is transferred via the underground heat exchanger 61. Is also supplied with cold (the ground is cooled). Further, when the underground heat storage control mode is being executed and the heating source 40 of the air conditioner 30 requires heating (heated circulating fluid), the heating is also performed underground through the underground heat exchanger 61. Is provided (the ground is warmed). That is, when the underground heat storage control mode is executed, the underground heat exchanger 61 does not provide the cooling fluid / heat necessary for the heat source device 40 to the circulating fluid, and the underground heat exchanger 60 functions as a heat source device. Not done.

(2-5) Air Conditioner The air conditioner 30 is a device that cools or heats the air conditioning target space.

  The air conditioner 30 mainly includes a heat source device 40, a plurality of indoor units 50, a flow rate adjustment valve 35, and an air conditioning controller 49 (see FIG. 2). In FIG. 2, the number of indoor units 50 is two, but the number of indoor units 50 is not limited to this, and may be three or more. The number of indoor units 50 may not be plural.

  In the air conditioner 30, the heat source unit 40 and the indoor unit 50 are connected by a liquid refrigerant communication pipe 33 and a gas refrigerant communication pipe 32 to constitute a refrigerant circuit 31 (see FIG. 2). More specifically, in the air conditioner 30, the compressor 41 of the heat source unit 40, the heat source side heat exchanger 43, and the heat source side expansion valve 44, which will be described later, by the liquid refrigerant communication pipe 33 and the gas refrigerant communication pipe 32, A use side heat exchanger 51 and an indoor side expansion valve 53 of the indoor unit 50 to be described later are connected to constitute the refrigerant circuit 31.

(2-5-1) Indoor Unit Each indoor unit 50 is installed in a space (for example, each room of a building or the like in which the air conditioning system 100 is installed) targeted by the indoor unit 50.

  The indoor unit 50 mainly includes a use-side heat exchanger 51, a fan 52, and an indoor-side expansion valve 53.

  The use side heat exchanger 51 exchanges heat between the refrigerant cooled or heated by the heat source device 40 and the room air. The use-side heat exchanger 51 functions as an evaporator that evaporates the refrigerant during the cooling operation of the air conditioner 30 and cools indoor air. The use-side heat exchanger 51 functions as a condenser that condenses the refrigerant during the heating operation of the air conditioner 30, and heats indoor air. The liquid side of the use side heat exchanger 51 is connected to the liquid refrigerant communication pipe 33, and the gas side of the use side heat exchanger 51 is connected to the gas refrigerant communication pipe 32.

  The fan 52 is rotated by a fan motor (not shown), thereby taking in indoor air and blowing it to the use side heat exchanger 51. The fan 52 promotes heat exchange between the refrigerant flowing through the use side heat exchanger 51 and room air.

  The indoor side expansion valve 53 is provided in a refrigerant pipe connecting the liquid side of the use side heat exchanger 51 and the liquid refrigerant communication pipe 33. The indoor side expansion valve 53 is an example of an expansion mechanism, and is an electric expansion valve with a variable opening provided for adjusting the flow rate of the refrigerant flowing through the use side heat exchanger 51.

(2-5-2) Heat source machine The heat source machine 40 mainly has the compressor 41, the four-way switching valve 42, the heat source side heat exchanger 43, and the heat source side expansion valve 44 as shown in FIG.

  The compressor 41, the four-way switching valve 42, the heat source side heat exchanger 43, and the heat source side expansion valve 44 are connected by a refrigerant pipe. Specifically, the suction port of the compressor 41 and the four-way switching valve 42 are connected by a suction pipe 45a (see FIG. 2). The discharge port of the compressor 41 and the four-way switching valve 42 are connected by a discharge pipe 45b (see FIG. 2). The four-way switching valve 42 and the gas side of the heat source side heat exchanger 43 are connected by a first gas refrigerant pipe 45c (see FIG. 2). The heat source side heat exchanger 43 and the liquid refrigerant communication pipe 33 are connected by a liquid refrigerant pipe 45d (see FIG. 2). The liquid refrigerant pipe 45d is provided with a heat source side expansion valve 44 (see FIG. 2). The four-way switching valve 42 and the gas refrigerant communication pipe 32 are connected by a second gas refrigerant pipe 45e (see FIG. 2).

  The compressor 41 drives a compression mechanism with a motor (not shown), thereby sucking low-pressure gas refrigerant from the suction pipe 45a and discharging high-pressure gas refrigerant compressed by the compression mechanism to the discharge pipe 45b. The compressor 41 is a variable capacity inverter type compressor. Although the compressor 41 is a rotary compressor, it is not limited to this, For example, a scroll compressor may be sufficient.

  The four-way switching valve 42 switches the flow direction of the refrigerant when the air conditioner 30 is switched between the cooling operation and the heating operation. During the cooling operation, the discharge pipe 45b and the first gas refrigerant pipe 45c are connected, and the suction pipe 45a and the second gas refrigerant pipe 45e are connected (see the solid line in FIG. 2). On the other hand, during the heating operation, the discharge pipe 45b and the second gas refrigerant pipe 45e are connected, and the suction pipe 45a and the first gas refrigerant pipe 45c are connected (see the broken line in FIG. 2).

  The heat source side heat exchanger 43 performs heat exchange between the refrigerant flowing in the refrigerant circuit 31 and the circulating fluid passing through the heat source side heat exchanger 43. In the heat source side heat exchanger 43, the liquid refrigerant pipe 45d is connected to the liquid side of the flow path through which the refrigerant flows, and the first gas refrigerant pipe 45c is connected to the gas side of the flow path through which the refrigerant flows (see FIG. 2). . Moreover, the piping 21 is connected to the heat source side heat exchanger 43 (refer FIG. 2). A flow rate adjustment valve 35 is provided on the upstream side of the heat source side heat exchanger 43 in the flow direction of the circulating fluid in the pipe 21. The heat source side heat exchanger 43 functions as a condenser that condenses the refrigerant by receiving cold heat from the circulating fluid during the cooling operation. The heat source side heat exchanger 43 functions as an evaporator that evaporates the refrigerant by receiving the supply of warm heat from the circulating fluid during the heating operation.

  The heat source side expansion valve 44 is an expansion mechanism for decompressing the refrigerant. The heat source side expansion valve 44 is an electric expansion valve with variable opening.

(2-5-3) Flow Control Valve The flow control valve 35 is provided corresponding to the heat source device 40 (see FIG. 1). Specifically, the flow rate adjustment valve 35 is provided on the upstream side of the inlet of the circulating fluid of each heat source device 40, in other words, on the upstream side of the heat source side heat exchanger 43 in the flow direction of the circulating fluid (FIG. 2). reference). The flow rate adjusting valve 35 is an electric valve with a variable opening that makes the amount of circulating fluid flowing to the heat source device 40, specifically, the amount of circulating fluid flowing to the heat source side heat exchanger 43 variable.

(2-5-4) Air-conditioning controller The air-conditioning controller 49 includes a CPU, a memory such as a RAM and a ROM, and the like. The air conditioning controller 49 is electrically connected to each component of the air conditioner 30, for example, the fan 52, the indoor side expansion valve 53, the compressor 41, the four-way switching valve 42, the heat source side expansion valve 44, and the flow rate adjustment valve 35. Yes. Further, the air conditioning controller 49 is configured to be able to communicate with the controller 70.

  The air conditioner controller 49 controls the air conditioner 30 by the CPU reading and executing the program stored in the memory. The air conditioning controller 49 exchanges control signals with a remote controller (not shown) for operating the indoor unit 50. The air conditioning controller 49 is based on commands (for example, operation / stop of the indoor unit 50, operation mode (cooling / heating), set temperature, etc.) input to the remote controller, measurement values of various sensors of the air conditioner 30 (not shown), and the like. Thus, various configurations of the air conditioner 30 such as the fan 52, the indoor side expansion valve 53, the compressor 41, the four-way switching valve 42, the heat source side expansion valve 44, and the flow rate adjustment valve 35 are controlled.

(2-6) Controller The controller 70 includes a CPU, a memory such as a RAM and a ROM, and the like. The controller 70 is electrically connected to the cooling tower 80, the boiler 90, the first pump 62, the second pump 20, and the temperature sensor 63 of the underground heat exchange device 60 (see FIG. 1). The controller 70 is electrically connected to a plurality of valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, 26b provided in the pipe 21 (the controller 70 and the valves 23a, 23b, 24a, 24b). , 25a, 25b, 26a, and 26b, the dotted lines indicating the connections are omitted in FIG. The controller 70 is configured to be able to communicate with each air conditioning controller 49. The controller 70 receives information regarding the operating status of each air conditioner 30 from each air conditioner controller 49. The information regarding the operating status of the air conditioner 30 includes, for example, information regarding the operation / stop of the heat source device 40, information regarding the air conditioning load of the air conditioner 30, information regarding the operation mode (heating / cooling mode) of the air conditioner 30, and the like.

  The controller 70 reads and executes the program stored in the memory so that the cooling tower 80, the boiler 90, the first pump 62, the second pump 20, and the valves 23a, 23b, 24a, 24b, 25a, 25b. , 26a and 26b are controlled. The controller 70 is based on the measured value of the temperature sensor 63 and the information on the operating status of the air conditioner 30 received from the air conditioning controller 49, the cooling tower 80, the boiler 90, the first pump 62, the second pump 20, and the valve 23a. , 23b, 24a, 24b, 25a, 25b, 26a, 26b.

  The controller 70 is configured to selectively execute two control modes (a first control mode and a second control mode). Further, the controller 70 is configured to be able to further execute the underground heat storage control mode during the second control mode.

  In the first control mode, the cooling tower 80 and the boiler 90 are not used, and the air conditioning device 30 performs air conditioning using the heat of the circulating fluid cooled or heated by the underground heat exchange device 60. It is. The second control mode is a control mode in which the air conditioner 30 performs air conditioning using the heat of the circulating fluid cooled by the cooling tower 80 or heated by the boiler 90 without using the underground heat exchange device 60. It is. In the underground heat storage control mode, in the second control mode, a part of the circulating fluid cooled by the cooling tower 80 or a part of the circulating fluid heated by the boiler 90 is caused to flow to the underground heat exchanger 61. In this operation mode, the heat of the circulating fluid (cold or warm) is also supplied to the underground heat exchanger 61. The underground heat storage control mode is a control mode executed in parallel with the second control mode.

  Control mode selection processing by the controller 70 and each configuration in each control mode (cooling tower 80, boiler 90, first pump 62, second pump 20, and valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, The operation 26b) will be described later.

(3) Control mode selection processing The control mode selection processing by the controller 70 and each configuration in each control mode (cooling tower 80, boiler 90, first pump 62, second pump 20, and valves 23a, 23b, 24a, The operation of 24b, 25a, 25b, 26a, 26b) will be described.

  First, when the air conditioner 30 performs the heating operation, the control mode selection processing by the controller 70 and the operation of each component in each control mode will be described with reference to FIGS.

  Here, before the start of step S1 described below, the air conditioning system 100 is stopped (the air conditioner 30, the cooling tower 80, the boiler 90, the first pump 62, and the second pump 20 are all stopped). The following description will be made on the assumption that the valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, and 26b are all closed.

  The controller 70 starts the heating operation of the air conditioner 30 based on the information regarding the operation state of the air conditioner 30 transmitted from the air conditioner controller 49 (the heat source unit 40 of the air conditioner 30 is activated, and the heat source unit 40 is heated). When it is determined that it is necessary to provide the control mode, the control mode selection process is performed as follows.

  First, the controller 70 selects and executes the first control mode at the start of operation of the air conditioning system 100 (step S1). Specifically, the controller 70 sends a command to open the valve body to the valves 23 a and 23 b and sends a start command to the first pump 62. When the valves 23 a and 23 b are opened and the first pump 62 is operated, the circulating fluid heated by the underground heat in the underground heat exchanger 61 of the underground heat exchange device 60 passes through the valve 23 a and passes through the heat source device 40. And flows to the heat source unit 40 via the flow rate adjustment valve 35 (see the arrow in FIG. 4). When there is a closed flow rate adjustment valve 35, the circulating fluid does not flow through the heat source device 40 corresponding to the flow rate adjustment valve 35. The circulating fluid that has exchanged heat with the refrigerant in the heat source device 40 passes through the valve 23b and returns to the underground heat exchanger 61 (see the arrow in FIG. 4).

  Next, in step S2, the controller 70 uses the measured value transmitted from the temperature sensor 63, and the temperature of the refrigerant at the outlet of the underground heat exchanger 61 (hereinafter referred to as the underground heat exchange outlet temperature T). Is lower than the first temperature T1 (for example, 10 ° C.). Since the underground heat exchange outlet temperature T is substantially equal to the underground temperature, it is determined in step S2 whether the underground temperature is lower than the first temperature T1. If it is determined in step S2 that the underground heat exchange outlet temperature T <the first temperature T1, the process proceeds to step S3. Step S2 is repeatedly executed until it is determined that the underground heat exchange outlet temperature T <the first temperature T1.

  In general, the temperature in the ground is stable compared to the temperature in the atmosphere, and shows a substantially constant value throughout the year. Therefore, by using the underground heat as a heat source for the air conditioner 30, the air conditioner 30 can be efficiently used. It is possible to perform the operation. However, since the underground heat is not inexhaustible, by collecting heat, the underground temperature gradually decreases, and the operating efficiency of the air conditioner 30 may gradually deteriorate. Step S <b> 2 is a step of determining whether or not the temperature in the ground has decreased to the extent that the operating efficiency of the air conditioner 30 deteriorates as a result of using the heat in the ground for heating the circulating fluid.

  In step S3, the controller 70 ends the first control mode, selects the second control mode, and executes it. Specifically, in order to end the first control mode, the controller 70 sends a command to the valves 23a and 23b to close the valve body and sends a stop command to the first pump 62. Further, the controller 70 sends a command to open the valve body to the valves 24 a and 24 b and sends a start command to the second pump 20 and the boiler 90 in order to execute the second control mode. When the valves 24 a and 24 b are opened and the second pump 20 and the boiler 90 are operated, the circulating fluid heated by the boiler 90 passes through the valve 24 a and is sent toward the heat source device 40, and passes through the flow rate adjustment valve 35. It flows to the heat source unit 40 (see the arrow in FIG. 5). When there is a closed flow rate adjustment valve 35, the circulating fluid does not flow through the heat source device 40 corresponding to the flow rate adjustment valve 35. The circulating fluid that has exchanged heat with the refrigerant in the heat source device 40 passes through the valve 24b and returns to the boiler 90 (see the arrow in FIG. 5). After step S3 ends, the process proceeds to step S4.

  In step S <b> 4, based on the information regarding the operating state of the air conditioner 30 transmitted from the air conditioning controller 49, the controller 70 generates excessive heat in the boiler 90 that is necessary for the air conditioner 30 to perform air conditioning. Determine whether or not. Specifically, the controller 70 determines whether or not the total air conditioning load of the air conditioner 30 is smaller than the stop load of the boiler 90. In other words, even if the boiler 90 is operated at the lowest load that can be operated (in a state where the boiler 90 cannot be operated at a lower load), an excess capacity state is generated in which the amount of heat higher than the heat required by the heat source device 40 is generated. It is determined whether or not the error occurs. Step S <b> 4 is repeated until it is determined that the total air conditioning load of the air conditioner 30 is smaller than the stop load of the boiler 90. If it is determined in step S4 that the total air conditioning load of the air conditioner 30 is smaller than the stop load of the boiler 90, the process proceeds to step S5.

  In step S5, the controller 70 further selects the underground heat storage control mode and executes it in parallel while executing the second control mode. Specifically, the controller 70 opens the valve body with respect to the valves 26a and 26b when the valves 24a and 24b are opened and the second pump 20 and the boiler 90 are in operation (second control mode). Send a command. In a state where the valves 24a, 24b, 26a, 26b are opened and the second pump 20 and the boiler 90 are operating, a part of the circulating fluid heated by the boiler 90 passes through the valve 26a and exchanges underground heat. Flows into the vessel 61 (see arrow in FIG. 6). The circulating fluid that has provided the heat to the ground in the ground heat exchanger 61 returns to the boiler 90 through the valve 26b (see the arrows in FIG. 6). By executing the underground heat storage control mode in this way, it is possible to continue operation without stopping the boiler 90 due to excessive capacity, and it is possible to avoid a state in which the boiler 90 repeats start / stop. Further, surplus heat of the boiler 90 (heat more than that required for the air conditioner 30 to perform air conditioning) is stored in the ground, and the ground temperature can be recovered.

  Next, in step S6, the controller 70 uses the measured value transmitted from the temperature sensor 63 to change the underground heat exchange outlet temperature T to a second temperature T2 (a temperature higher than the first temperature T1, for example, 12 ° C. It is determined whether it is higher. That is, in step S6, it is determined whether or not the underground temperature is higher than the second temperature T2 (whether or not the underground temperature has recovered to the second temperature T2).

  If it is determined in step S6 that the underground heat exchange outlet temperature T> the second temperature T2, the process returns to step S1, and the controller 70 selects and executes the first control mode again. Specifically, the controller 70 first ends the second control mode and the underground heat storage control mode. That is, the controller 70 sends a command to the valves 24a, 24b, 26a, and 26b to close the valve body, and sends a stop command to the second pump 20 and the boiler 90. Thereafter, in order to execute the first control mode, the controller 70 sends a command to the valves 23a and 23b to open the valve body and sends a start command to the first pump 62.

  If it is determined in step S6 that the underground heat exchange outlet temperature T ≦ second temperature T2, the process proceeds to step S7. In step S <b> 7, the controller 70 determines whether or not the total air conditioning load of the air conditioner 30 is greater than or equal to the stop load of the boiler 90 based on the information regarding the operating state of the air conditioner 30 transmitted from the air conditioner controller 49. If it is determined in step S7 that the total air conditioning load of the air conditioner 30 is equal to or greater than the stop load of the boiler 90, the process proceeds to step S8. On the other hand, when it is determined in step S7 that the total air conditioning load of the air conditioner 30 is smaller than the stop load of the boiler 90, the process returns to step S6.

  In step S8, the controller 70 ends the underground heat storage control mode (the second control mode continues). Specifically, the controller 70 sends a command to the valves 26a and 26b to close the valve body. Thereafter, the process returns to step S4.

  The control mode selection process by the controller 70 and the execution of the control mode by the controller 70 do not require the air conditioner 30 (more specifically, the heat source unit 40) to stop and flow the circulating fluid to the heat source unit 40. Will continue until. When all of the air conditioner 30 (more specifically, the heat source device 40) is stopped, all of the valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, and 26b are closed, and the cooling tower 80, the boiler 90, and the first pump. 62 and the second pump 20 are all stopped.

  Next, when the air conditioner 30 is performing the cooling operation, the control mode selection processing by the controller 70 and the operation of each component in each control mode will be described with reference to FIG.

  First, the controller 70 selects and executes the first control mode at the start of operation of the air conditioning system 100 (step S11). Since the command sent by the controller 70 when the first control mode is executed is the same as that in step S1, description thereof is omitted.

  Next, in step S12, the controller 70 determines whether or not the underground heat exchange outlet temperature T is higher than the third temperature T3 using the measured value transmitted from the temperature sensor 63. In other words, in step S12, it is determined whether the underground temperature is higher than the third temperature T3. If it is determined in step S12 that the underground heat exchange outlet temperature T> the third temperature T3, the process proceeds to step S13. Step S12 is repeatedly executed until it is determined that the underground heat exchange outlet temperature T> the third temperature T3.

  In step S13, the controller 70 ends the first control mode and selects and executes the second control mode. Specifically, in order to end the first control mode, the controller 70 sends a command to the valves 23a and 23b to close the valve body and sends a stop command to the first pump 62. Further, the controller 70 sends a command to open the valve body to the valves 25 a and 25 b and sends a start command to the second pump 20 and the cooling tower 80 in order to execute the second control mode. When the valves 25a and 25b are opened and the second pump 20 and the cooling tower 80 are operated, the circulating fluid cooled by the cooling tower 80 passes through the valve 25a toward the heat source unit 40, and the flow rate adjusting valve 35 is To the heat source unit 40. When there is a closed flow rate adjustment valve 35, the circulating fluid does not flow through the heat source device 40 corresponding to the flow rate adjustment valve 35. The circulating fluid that has exchanged heat with the refrigerant in the heat source device 40 passes through the valve 25 b and returns to the cooling tower 80. After step S13 ends, the process proceeds to step S14.

  In step S <b> 14, based on the information regarding the operating state of the air conditioner 30 transmitted from the air conditioning controller 49, it is determined whether or not excess heat necessary for the air conditioner 30 to perform air conditioning is generated in the cooling tower 80. judge. Specifically, the controller 70 determines whether or not the total air conditioning load of the air conditioner 30 is smaller than the stop load of the cooling tower 80. In other words, even if the cooling tower 80 is operated at the lowest load that can be operated (in a state where the cooling tower 80 cannot be operated at a lower load), the cooling capacity is generated more than necessary by the heat source unit 40. It is determined whether or not the error occurs. Step S <b> 14 is repeated until it is determined that the total air conditioning load of the air conditioner 30 is smaller than the stop load of the cooling tower 80. If it is determined in step S14 that the total air conditioning load of the air conditioner 30 is smaller than the stop load of the cooling tower 80, the process proceeds to step S15.

  In step S15, the controller 70 further selects the underground heat storage control mode and executes it in parallel while executing the second control mode. Specifically, the controller 70 sends a command to the valves 26a and 26b to further open the valve body in a state where the valves 25a and 25b are opened and the second pump 20 and the cooling tower 80 are operating. When the valves 25a, 25b, 26a, and 26b are opened and the second pump 20 and the cooling tower 80 are operating, a part of the circulating fluid cooled by the cooling tower 80 passes through the valve 26a and is underground. It flows to the heat exchanger 61. The circulating fluid that has supplied cold to the ground in the underground heat exchanger 61 returns to the cooling tower 80 through the valve 26b. By executing the underground heat storage control mode in this way, it is possible to continue the operation without stopping the cooling tower 80 due to excessive capacity, and it is possible to avoid a state in which the cooling tower 80 repeats start / stop. . Further, surplus heat (excess cooling heat) of the cooling tower 80 is stored in the ground, and the ground temperature can be recovered.

  Next, in step S16, the controller 70 uses the measured value transmitted from the temperature sensor 63 to determine whether the underground heat exchange outlet temperature T is lower than the fourth temperature T4 (temperature lower than the third temperature T3). It is determined whether or not. That is, in step S16, it is determined whether or not the underground temperature is lower than the fourth temperature T4 (whether or not the underground temperature has decreased to the fourth temperature T4).

  If it is determined in step S16 that the underground heat exchange outlet temperature T <the fourth temperature T4, the process returns to step S11, and the controller 70 selects and executes the first control mode again. Specifically, the controller 70 first ends the second control mode and the underground heat storage control mode. That is, the controller 70 sends a command to the valves 25a, 25b, 26a, and 26b to close the valve body, and sends a stop command to the second pump 20 and the cooling tower 80. Thereafter, in order to execute the first control mode, the controller 70 sends a command to the valves 23a and 23b to open the valve body and sends a start command to the first pump 62.

  If it is determined in step S16 that the underground heat exchange outlet temperature T ≧ the fourth temperature T4, the process proceeds to step S17. In step S <b> 17, the controller 70 determines whether the total air conditioning load of the air conditioner 30 is equal to or greater than the stop load of the cooling tower 80 based on the information regarding the operation state of the air conditioner 30 transmitted from the air conditioner controller 49. . If it is determined in step S17 that the total air conditioning load of the air conditioner 30 is greater than or equal to the stop load of the cooling tower 80, the process proceeds to step S18. On the other hand, if it is determined in step S17 that the total air conditioning load of the air conditioner 30 is smaller than the stop load of the cooling tower 80, the process returns to step S16.

  In step S18, the controller 70 ends the underground heat storage control mode (the second control mode continues). Specifically, the controller 70 sends a command to the valves 26a and 26b to close the valve body. Thereafter, the process returns to step S14.

  The control mode selection process by the controller 70 and the execution of the control mode by the controller 70 do not require the air conditioner 30 (more specifically, the heat source unit 40) to stop and flow the circulating fluid to the heat source unit 40. Will continue until. When all of the air conditioner 30 (more specifically, the heat source device 40) is stopped, all of the valves 23a, 23b, 24a, 24b, 25a, 25b, 26a, and 26b are closed, and the cooling tower 80, the boiler 90, and the first pump. 62 and the second pump 20 are all stopped.

(4) Features The air conditioning system 100 of the present embodiment has the following features.

(4-1)
The air conditioning system 100 of the present embodiment includes a ground heat exchange device 60 as an example of a first heat source device, a cooling tower 80 and a boiler 90 as an example of a second heat source device different from the first heat source device, and an air conditioner. The apparatus 30 and the controller 70 as an example of a control part are provided. The underground heat exchange device 60 has an underground heat exchanger 61, and cools or heats the circulating fluid in the underground heat exchanger 61 using the underground heat. The cooling tower 80 and the boiler 90 cool or heat the circulating fluid using electricity or fuel. The air conditioner 30 performs air conditioning using the heat of the circulating fluid. The controller 70 selectively executes the first control mode and the second control mode. In the first control mode, the cooling tower 80 and the boiler 90 are not used, and the air conditioner 30 is air-conditioned using the heat of the circulating fluid cooled or heated by the underground heat exchange device 60. In the second control mode, the ground heat exchange device 60 is not used, and the air conditioner 30 performs air conditioning using the heat of the circulating fluid cooled or heated by the cooling tower 80 or the boiler 90. In the second control mode, the controller 70 also supplies heat of the circulating fluid to the underground heat exchanger 61 when surplus heat more than necessary for the air conditioner 30 to perform air conditioning occurs.

  Here, in the case where the circulating fluid is cooled or heated by the cooling tower 80 or the boiler 90 and the surplus heat necessary for the air conditioner 30 to perform air conditioning is generated, the underground heat exchanger 61 Also the heat of the circulating fluid is donated. Therefore, the air conditioning system 100 with excellent efficiency can be realized without wasting excess heat.

(4-2)
In the air conditioning system 100 of the present embodiment, the controller 70 executes the first control mode when the operation of the air conditioning system 100 is started.

  During the heating operation of the air conditioner 30 (when it is necessary to supply heat to the heat source device 40), the controller 70 reduces the underground temperature below the first temperature T1 during the execution of the first control mode. In this case, the second control mode is started instead of the first control mode. Further, during the heating operation of the air conditioner 30, the controller 70 enters the second control mode when the underground temperature rises above the second temperature T2 higher than the first temperature T1 during the execution of the second control mode. Instead, the first control mode is started.

  On the other hand, during the cooling operation of the air conditioner 30 (when it is necessary to supply cold heat to the heat source device 40), the controller 70 increases the underground temperature above the third temperature T3 during the execution of the first control mode. In this case, the second control mode is started instead of the first control mode. Further, during the cooling operation of the air conditioner 30, the controller 70 enters the second control mode when the underground temperature falls below the fourth temperature T4 lower than the third temperature T3 during the execution of the second control mode. Instead, the first control mode is started.

  Here, even when the air conditioner 30 is in the heating operation and the underground temperature is lowered, the air conditioner 30 can be efficiently operated by executing the second control mode instead of the first control mode. On the other hand, when the underground temperature has recovered (increased), switching from the second control mode to the first control mode enables efficient heating operation of the air conditioner 30 using underground heat. .

  Further, even when the air conditioner 30 is in the cooling operation and the underground temperature rises, the air conditioner 30 can be efficiently operated by executing the second control mode instead of the first control mode. On the other hand, when the underground temperature recovers (decreases), it is possible to perform an efficient cooling operation of the air conditioner 30 using the underground heat by switching the first control mode from the second control mode.

(4-3)
In the air conditioning system 100 of the present embodiment, in the second control mode, when the cooling tower 80 or the boiler 90 is stopped due to excessive capacity, the controller 70 determines that surplus heat is generated in the underground heat exchanger 61. Provides heat for the circulating fluid.

  Here, it is possible to prevent the situation where the cooling tower 80 or the boiler 90 repeats starting / stopping in the second control mode, and the cooling tower 80 and the boiler 90 can be operated efficiently.

(5) Modifications Modifications of the above embodiment are shown below. Note that the modified examples may be combined as appropriate within a range that does not contradict each other.

(5-1) Modification A
Although the air conditioning system 100 of the said embodiment has the cooling tower 80 and the boiler 90, it is not limited to this, You may have only any one. For example, when the air conditioner 30 performs only the heating operation, the air conditioning system 100 may include only the boiler 90.

(5-2) Modification B
In the air conditioning system 100 of the above embodiment, the underground heat storage control mode is executed both during the heating operation of the air conditioner 30 and during the cooling operation of the air conditioner 30, but is not limited to this. For example, the air conditioning system 100 may be configured to execute the underground heat storage control mode only during the heating operation of the air conditioner 30.

(5-3) Modification C
In the air conditioning system 100 of the above-described embodiment, the use-side heat exchanger 51 directly exchanges heat between the refrigerant and the air in the air-conditioning target space, but is not limited thereto. For example, in the air conditioning system 100, heat is exchanged between the refrigerant and the second circulating fluid (for example, water) in the use-side heat exchanger 51, and the second circulating fluid is transferred to the air-conditioning target space. You may be comprised so that the air of space may be heat-exchanged.

(5-4) Modification D
In the air conditioning system 100 of the above embodiment, the valve 26a and / or the valve 26b may be configured so that the opening degree can be adjusted. For example, the controller 70 increases the degree of deviation according to the degree of deviation between the air conditioning load of the air conditioner 30 and the stop load of the cooling tower 80 or the boiler 90 (as the air conditioning load is smaller than the stop load). The amount of circulating fluid flowing through the heat exchanger 61 may be increased.

(5-5) Modification E
In the air conditioning system 100 of the above embodiment, the temperature of the circulating fluid at the outlet of the underground heat exchanger 61 is measured by the temperature sensor 63 in order to grasp the underground temperature. However, the present invention is not limited to this. Absent. For example, the temperature sensor may be configured to directly measure the temperature in the ground.

  By using the present invention, a heat source device that uses geothermal heat, a heat source device that uses electricity or fuel, and an air conditioner that performs air conditioning using the heat of the circulating fluid cooled / heated by these heat source devices It is possible and useful to provide an air conditioning system with excellent efficiency.

30 Air conditioner 60 Ground heat exchanger (first heat source device)
61 Ground heat exchanger 70 Controller (control part)
80 Cooling tower (second heat source device)
90 boiler (second heat source device)
100 Air-conditioning system T Ground heat exchange outlet temperature (Ground temperature)
T1 First temperature T2 Second temperature

JP 2012-047360 A

Claims (3)

A first heat source device (60) that has a ground heat exchanger (61) and cools or heats the circulating fluid in the ground heat exchanger using heat in the ground;
A second heat source device (80, 90) separate from the first heat source device for cooling or heating the circulating fluid using electricity or fuel;
An air conditioner (30) that performs air conditioning using the heat of the circulating fluid;
A first control mode in which the air conditioning device performs air conditioning using heat of the circulating fluid cooled or heated by the first heat source device without using the second heat source device; and the first heat source device. A control unit (70) that selectively executes a second control mode in which the air-conditioning apparatus performs air conditioning using heat of the circulating fluid cooled or heated by the second heat source device without being used; ,
With
In the second control mode, the control unit also supplies heat of the circulating fluid to the underground heat exchanger when excessive heat necessary for the air conditioner to perform air conditioning occurs.
Air conditioning system (100). The controller is
The first control mode is executed at the start of operation of the air conditioning system,
When the underground temperature falls below the first temperature during the execution of the first control mode, the second control mode is started instead of the first control mode,
The first control mode is started instead of the second control mode when the underground temperature rises from a second temperature higher than the first temperature during the execution of the second control mode.
The air conditioning system according to claim 1. In the second control mode, the controller supplies heat of the circulating fluid to the underground heat exchanger as the surplus heat is generated when the second heat source device is stopped due to excessive capacity. To
The air conditioning system according to claim 1 or 2.

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