Computation device, computation method, program, control device, control method, and control program

Abstract

A computation device (200) according to the present disclosure is a computation device (200) that determines a heat storage mode when heat storage is performed in a geothermal heat utilization system (1) including a heat source well facility (10) and an auxiliary heat storage facility (100) including a cooling tower (130), a chiller (150), and a refrigerant circuit (101). The computation device (200) includes an acquisition unit (210) that acquires a simulation condition, a first calculation unit (220) that calculates, based on the simulation condition, a first simulation result that is a result of a simulation in a first heat storage mode in which heat storage by the cooling tower (130) is included, a second calculation unit (230) calculating, based on the simulation condition, a second simulation result that is a result of a simulation in a second heat storage mode in which heat storage by the chiller (150) is included, and a determination unit (250) that determines one of the first heat storage mode and the second heat storage mode based on the first simulation result and the second simulation result.

Description

Calculation device, calculation method, program, control device, control method, control program

[0001] This disclosure relates to a computing device, a computing method, a program, a control device, a control method, and a control program. This application claims priority to Japanese Patent Application No. 2021-78637, filed May 6, 2021, the contents of which are incorporated herein by reference.

[0002] BACKGROUND ART In recent years, geothermal energy utilization systems that utilize groundwater as a heat or cold source have been proposed.

[0003] For example, Patent Document 1 proposes a geothermal energy utilization system that includes a heat source well facility having a hot water well, a cold water well, and well-side piping connecting the wells, and a heat source unit having a refrigeration cycle with a condenser and an evaporator. This geothermal energy utilization system is capable of switching between a cold heat storage operation mode and a cold heat release operation mode depending on the season. In the cold heat storage operation mode, heat is exchanged between the evaporator of the heat source unit and the well-side piping, and between the condenser of the heat source unit and the load. In the cold heat release operation mode, heat is exchanged between the condenser of the heat source unit and the well-side piping, and between the evaporator of the heat source unit and the load.

[0004] Japanese Patent Application Laid-Open No. 2018-173257

[0005] However, in a geothermal energy utilization system such as that described in Patent Document 1, it is desirable to always operate it more efficiently. For example, environmental conditions such as temperature and humidity change daily. For this reason, it is preferable to operate the geothermal energy utilization system in an operation mode that is more suitable not only for the season, such as summer or winter, but also for the operating conditions.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a calculation device, a calculation method, a program, a control device, a control method, and a control program that can operate in a heat storage mode that suits the environmental conditions.

[0007] In order to solve the above problem, a computing device according to the present disclosure is a computing device for determining a heat storage mode when storing heat in a geothermal heat utilization system including a heat source well facility including a hot water well, a cold water well, well-side piping connecting the hot water well and the cold water well, and a pump provided on the well-side piping, and a heat storage auxiliary facility having a cooling tower, a chiller, and a refrigerant circuit connected to at least one of the cooling tower and the chiller and capable of heat exchange with the well-side piping, the computing device comprising: an acquisition unit for acquiring simulation conditions; a first calculation unit for calculating a first simulation result that is the result of a simulation of a first heat storage mode including heat storage by the cooling tower based on the simulation conditions; a second calculation unit for calculating a second simulation result that is the result of a simulation of a second heat storage mode including heat storage by the chiller based on the simulation conditions; and a determination unit for determining one of the first heat storage mode and the second heat storage mode based on the first simulation result and the second simulation result.

[0008] The calculation method disclosed herein is a calculation method for determining a heat storage mode when storing heat in a geothermal energy utilization system that includes a heat source well facility that includes a hot water well, a cold water well, well-side piping connecting the hot water well and the cold water well, and a pump installed on the well-side piping, and a heat storage auxiliary facility that includes a cooling tower, a chiller, and a refrigerant circuit that is connected to at least one of the cooling tower and the chiller and is capable of heat exchange with the well-side piping, and the calculation method includes obtaining simulation conditions, calculating a first simulation result that is the result of a simulation of a first heat storage mode that includes heat storage by the cooling tower based on the simulation conditions, calculating a second simulation result that is the result of a simulation of a second heat storage mode that includes heat storage by the chiller based on the simulation conditions, and determining one of the first heat storage mode and the second heat storage mode based on the first simulation result and the second simulation result.

[0009] The program disclosed herein is a method for determining a heat storage mode when storing heat in a geothermal energy utilization system that includes a heat source well facility including a hot water well, a cold water well, well-side piping connecting the hot water well and the cold water well, and a pump installed on the well-side piping, and a heat storage auxiliary facility that includes a cooling tower, a chiller, and a refrigerant circuit that is connected to at least one of the cooling tower and the chiller and is capable of heat exchange with the well-side piping. The program acquires simulation conditions, calculates a first simulation result that is a result of a simulation of a first heat storage mode that includes heat storage by the cooling tower based on the simulation conditions, calculates a second simulation result that is a result of a simulation of a second heat storage mode that includes heat storage by the chiller based on the simulation conditions, and determines either the first heat storage mode or the second heat storage mode based on the first simulation result and the second simulation result.

[0010] According to the calculation device, calculation method, program, control device, control method, and control program of the present disclosure, it is possible to operate in a heat storage mode suited to environmental conditions.

[0011] 1 is a system diagram showing a schematic configuration of a geothermal utilization system according to an embodiment of the present disclosure. FIG. 2 is a block diagram showing a functional configuration of a geothermal utilization system according to an embodiment of the present disclosure. FIG. 3 is a diagram showing the flows of groundwater and a medium when operating in a cooling operation mode in a geothermal utilization system according to an embodiment of the present disclosure. FIG. 4 is a diagram showing the flows of groundwater and a medium when operating in a heating operation mode in a geothermal utilization system according to an embodiment of the present disclosure. FIG. 5 is a diagram showing the flows of groundwater and a medium when performing cold water thermal storage operation in a first thermal storage mode in a geothermal utilization system according to an embodiment of the present disclosure. FIG. 6 is a diagram showing the flows of groundwater and a medium when performing cold water thermal storage operation in a second thermal storage mode in a geothermal utilization system according to an embodiment of the present disclosure. FIG. 7 is a flowchart showing the flow of a calculation method according to an embodiment of the present disclosure. FIG. 8 is a flowchart showing the flow of a control method according to an embodiment of the present disclosure. FIG. 9 is a diagram showing an example of the hardware configuration of a computer provided in a calculation device and a control device, respectively, according to an embodiment of the present disclosure.

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In all drawings, the same or corresponding components are denoted by the same reference numerals, and common descriptions will be omitted.

[0013] <Embodiments> An embodiment of a geothermal heat utilization system according to the present disclosure will be described with reference to Figures 1 to 8. (Configuration of geothermal heat utilization system) As shown in Figures 1 and 2, a geothermal heat utilization system 1 mainly includes a heat source well facility 10, a thermal storage auxiliary facility 100, a heat exchanger 4 (see Figure 1), a computing device 200 (see Figure 2), and a control device 300 (see Figure 2).

[0014] (Configuration of Heat Source Well Facility) As shown in FIG. 1 , the heat source well facility 10 mainly includes a hot water well 21 , a cold water well 22 , well-side piping 3 , and a pump 31 .

[0015] The hot water well 21 and the cold water well 22 each extend from the ground into the aquifer. The hot water well 21 and the cold water well 22 are configured to take in groundwater from the aquifer and return groundwater from the inside of the hot water well 21 and the cold water well 22 to the aquifer.

[0016] The heat source well facility 10 pumps up groundwater from one of the hot water well 21 and the cold water well 22, exchanges heat in the heat exchanger 4, and then injects the heat-exchanged groundwater into the other of the hot water well 21 and the cold water well 22. In other words, the heat source well facility 10 has two operating modes: one in which groundwater is pumped from the hot water well 21 and injected into the cold water well 22, and one in which groundwater is pumped from the cold water well 22 and injected into the hot water well 21.

[0017] The well-side piping 3 connects the hot water well 21 and the cold water well 22. Both ends of the well-side piping 3 extend into the hot water well 21 and the cold water well 22. For example, the well-side piping 3 may be immersed at both ends in the groundwater of each of the hot water well 21 and the cold water well 22 so as to connect the hot water well 21 and the cold water well 22.

[0018] A pump 31 is provided on the well-side piping 3. A pump 31 is provided on each end of the well-side piping 3. The pump 31 pumps water from the hot water well 21 and the cold water well 22 to the well-side piping 3. For example, the pumps 31 may be provided on both ends of the well-side piping 3 and immersed in the groundwater in the hot water well 21 and the cold water well 22. For example, the output of the pump 31 may be changed by inverter control.

[0019] The heat exchanger 4 exchanges heat between the groundwater in the well-side piping 3 and the medium on the thermal storage auxiliary equipment 100 side. For example, the heat exchanger 4 exchanges heat between groundwater pumped up from the hot water well 21 and flowing in the well-side piping 3 and the medium on the thermal storage auxiliary equipment 100 side. The groundwater after heat exchange flows from the heat exchanger 4 through the well-side piping 3 and is injected into the cold water well 22. For example, the heat exchanger 4 exchanges heat between the groundwater pumped up from the cold water well 22 and flowing in the well-side piping 3 and the medium on the thermal storage auxiliary equipment 100 side. The groundwater after heat exchange flows from the heat exchanger 4 through the well-side piping 3 and is injected into the hot water well 21. For example, the heat exchanger 4 may be provided on the well-side piping 3 above ground.

[0020] If the water that has passed through the heat exchanger 4 is hot water, hot water heat storage is performed in the hot water well 21. If the water that has passed through the heat exchanger 4 is cold water, cold water heat storage is performed in the cold water well 22. Here, "hot water" refers to water with a temperature higher than the initial underground temperature of the groundwater in the aquifer, and "cold water" refers to water with a temperature lower than the initial underground temperature of the groundwater in the aquifer. For example, the initial underground temperature of the groundwater in the aquifer is 18°C.

[0021] (Configuration of the heat storage auxiliary equipment) The heat storage auxiliary equipment 100 uses a medium that has undergone heat exchange with the groundwater in the well-side piping 3 in the heat exchanger 4. The heat storage auxiliary equipment 100 includes at least a cooling tower 130, a heat source unit 110, and a refrigerant circuit 101. In this embodiment, the heat storage auxiliary equipment 100 includes, for example, the heat source unit 110, an air conditioner 120, the cooling tower 130, and the refrigerant circuit 101. The heat storage auxiliary equipment 100 may also constitute an air conditioning system that includes, for example, the heat source unit 110 and the air conditioner 120.

[0022] For example, the heat source machine 110 may be a heat pump equipped with a condenser, an evaporator, a compressor, etc. The air conditioner 120 performs air conditioning of the space in which the air conditioner 120 is installed by exchanging heat with a medium (chilled water) supplied from the heat source machine 110.

[0023] The cooling tower 130 cools the cooling water by the heat of vaporization generated when the cooling water comes into contact with the atmosphere and evaporates. The cooling tower 130 circulates the cooling water between the cooling tower 130 and the second heat exchanger 140. The second heat exchanger 140 exchanges heat between the medium (cooling water) in the refrigerant circuit 101 on the air conditioning system side and the cooling water on the cooling tower 130 side. The second heat exchanger 140 cools the medium in the refrigerant circuit 101 on the air conditioning system side by exchanging heat with the cooling water cooled in the cooling tower 130. The heat source unit 110 and the cooling tower 130 constitute a chiller 150.

[0024] The refrigerant circuit 101 forms a flow path for the medium between the heat exchanger 4, the heat source unit 110, the air conditioner 120, and the second heat exchanger 140. The refrigerant circuit 101 is appropriately provided with a pump, an on-off valve, etc. (not shown), and circulates the medium through a predetermined route between the heat exchanger 4, the heat source unit 110, the air conditioner 120, and the second heat exchanger 140 depending on the operation mode. For example, the thermal storage auxiliary equipment 100 can switch between a cooling operation mode and a heating operation mode by switching the circulation route of the medium in the refrigerant circuit 101.

[0025] (Configuration of Cooling Operation Mode) As shown in FIG. 3 , in the cooling operation mode, cooling operation is performed on the thermal storage auxiliary equipment 100 side, and hot water thermal storage is performed in the hot water well 21. In this case, the pump 31 of the cold water well 22 pumps groundwater and sends it to the heat exchanger 4. The heat exchanger 4 exchanges heat between the groundwater in the well-side piping 3 and the medium flowing through the refrigerant circuit 101 on the thermal storage auxiliary equipment 100 side. On the thermal storage auxiliary equipment 100 side, the medium (cooling water) cooled by heat exchange in the heat exchanger 4 is sent to the heat source unit 110, where it exchanges heat with the medium (chilled water) on the air conditioner 120 side. This allows the air conditioner 120 connected to the heat source unit 110 to cool the room. On the other hand, the medium (cooling water) heated by heat exchange in the heat source unit 110 is sent back to the heat exchanger 4, cooled, and then circulated. In the heat exchanger 4, the groundwater is heated by heat exchange between the heated medium and the groundwater flowing in the well-side piping 3. The heated groundwater is injected into the hot water well 21 through the well-side piping 3, thereby storing hot water heat.

[0026] (Configuration of Heating Operation Mode) As shown in FIG. 4 , in the heating operation mode, heating operation is performed on the thermal storage auxiliary equipment 100 side, and cold water thermal storage is performed in the cold water well 22. In this case, the pump 31 of the hot water well 21 pumps groundwater (hot water) and sends it to the heat exchanger 4. The heat exchanger 4 exchanges heat between the groundwater in the well-side piping 3 and the medium flowing through the refrigerant circuit 101 on the thermal storage auxiliary equipment 100 side. On the thermal storage auxiliary equipment 100 side, the medium heated by heat exchange in the heat exchanger 4 is sent to the heat source unit 110, where it exchanges heat. This allows the air conditioner 120 connected to the heat source unit 110 to heat the room. On the other hand, the medium cooled by heat exchange in the heat source unit 110 is sent back to the heat exchanger 4 and circulates. In the heat exchanger 4, heat exchange occurs between the cooled medium and the groundwater flowing in the well-side piping 3, thereby cooling the groundwater. The cooled groundwater is poured into the cold water well 22 through the well-side piping 3, thereby storing cold water heat.

[0027] Furthermore, in winter (or at night) when the outside air temperature is low, the geothermal utilization system 1 can store cold water in the cold water well 22 by cooling groundwater without heating operation. When storing cold water, the geothermal utilization system 1 can switch the heat storage mode between a first heat storage mode including heat storage by the cooling tower 130 and a second heat storage mode including heat storage by the refrigerator 150. The geothermal utilization system 1 stores cold water in either the first heat storage mode or the second heat storage mode under the control of the control device 300, which will be described later.

[0028] (Configuration of First Heat Storage Mode) As shown in FIG. 5 , in the first heat storage mode, cooling water cooled by the heat of vaporization when the cooling water comes into contact with the atmosphere and is vaporized in the cooling tower 130 is sent to the second heat exchanger 140. In the second heat exchanger 140, heat exchange occurs between the cooling water and the medium in the refrigerant circuit 101. That is, the second heat exchanger 140 cools the medium in the refrigerant circuit 101 using the cooling water cooled in the cooling tower 130. The cooled medium is sent to the heat exchanger 4 and exchanges heat with the groundwater in the well-side piping 3. In this case, the pump 31 of the hot water well 21 pumps up groundwater (hot water) and sends it to the heat exchanger 4. As a result, the groundwater in the well-side piping 3 is cooled and injected into the cold water well 22, thereby storing cold water heat.

[0029] (Configuration of Second Heat Storage Mode) As shown in FIG. 6 , in the second heat storage mode, the cooling tower 130 and the heat source unit 110 are used as a chiller 150. In this case, the pump 31 of the hot water well 21 pumps up groundwater (hot water) and sends it to the heat exchanger 4. On the heat storage auxiliary equipment 100 side, the medium is sent to the heat source unit 110 from the second heat exchanger 140 side. The heat source unit 110 cools the medium (cold water) sent from the heat exchanger 4 side by heat exchange. The medium (cold water) cooled by heat exchange in the heat source unit 110 is sent to the heat exchanger 4. In the heat exchanger 4, heat exchange occurs between the cooled medium and groundwater flowing through the well-side piping 3, thereby cooling the groundwater. The cooled groundwater is injected into the cold water well 22 through the well-side piping 3, thereby performing cold water heat storage. On the other hand, the medium (cooling water) whose temperature has increased due to heat exchange with the medium (chilled water) on the heat exchanger 4 side in the heat source unit 110 is sent to the second heat exchanger 140. The second heat exchanger 140 cools the medium sent from the heat source unit 110 by exchanging heat with the cooling water cooled in the cooling tower 130.

[0030] 2, the computing device 200 determines the heat storage mode to be used when storing heat in the geothermal heat utilization system 1. The computing device 200 performs a simulation calculation in advance to determine whether the first heat storage mode or the second heat storage mode is appropriate for storing cold water heat when storing cold water heat in the geothermal heat utilization system 1. The computing device 200 determines whether the first heat storage mode or the second heat storage mode is to be used based on the results of the simulation calculation.

[0031] In this embodiment, the computing device 200 is provided in the geothermal energy utilization system 1. That is, the computing device 200 is provided at the installation location of the geothermal energy utilization system 1. The computing device 200 may be provided together with the control device 300, for example. The computing device 200 may be incorporated into the control device 300 as a part of the configuration of the control device 300. Furthermore, the computing device 200 may be provided at a location different from the installation location of the geothermal energy utilization system 1. For example, the computing device 200 may be provided so as to be able to communicate data with the control device 300 via an external network using a wired or wireless connection.

[0032] The computing device 200 functionally comprises an acquisition unit 210 , a first calculation unit 220 , a second calculation unit 230 , a temperature calculation unit 240 , and a determination unit 250 .

[0033] The acquisition unit 210 acquires simulation conditions. The acquisition unit 210 acquires simulation conditions that are the premise of the simulation calculations performed to determine the thermal storage mode. The acquired simulation conditions include, for example, outdoor air conditions. The outdoor air conditions may include, for example, at least one of outdoor air temperature and outdoor air humidity. The outdoor air conditions may include both outdoor air temperature and outdoor air humidity. In this embodiment, the outdoor air conditions include, for example, the outdoor air temperature (range) and outdoor air humidity (range) expected in the location (area) where the geothermal energy utilization system 1 is installed. The simulation conditions acquired by the acquisition unit 210 may include a pumped water temperature and an upper limit water supply temperature. The pumped water temperature is the temperature of groundwater that can be pumped from the hot water well 21. The upper limit water supply temperature is the upper limit of the temperature of groundwater supplied to the cold water well 22 when cold water thermal storage is performed in the cold water well 22. The upper limit water injection temperature is, for example, the upper limit of the water injection temperature at which a rise in the temperature of the groundwater in the cold water well 22 is suppressed when groundwater is injected into the cold water well 22. The acquisition unit 210 acquires the outdoor air temperature and outdoor air humidity as virtual outdoor air conditions for performing a simulation.

[0034] The acquisition unit 210 may include, as simulation conditions, specifications of the equipment constituting the heat source well facility 10 and the thermal storage auxiliary facility 100. The equipment specifications may include, for example, the pump 31 of the heat source well facility 10, the heat source unit 110 of the thermal storage auxiliary facility 100, the cooling tower 130, a pump (not shown) provided in the refrigerant circuit 101, and specifications of the medium on the thermal storage auxiliary facility 100 side.

[0035] The acquisition unit 210 may acquire the simulation conditions by, for example, receiving input of numerical values ​​of each simulation condition by an operator. The acquisition unit 210 may acquire the simulation conditions from, for example, a database that stores specifications of each device that constitutes the heat source well facility 10 and the thermal storage auxiliary facility 100.

[0036] The first calculation unit 220 performs a simulation calculation of a first heat storage mode, including heat storage using the cooling tower 130, based on the simulation conditions acquired by the acquisition unit 210. The first calculation unit 220 performs a simulation calculation of an operation in a first heat storage mode, including heat storage using the cooling tower 130, as shown in FIG. 5 , based on the simulation conditions. The first calculation unit 220 performs a simulation calculation of a case in which cold water heat storage is performed in the cold water well 22 by cooling a medium using the cooling tower 130. The first calculation unit 220 performs multiple simulation calculations by varying the temperature and humidity within the ranges of the virtual outdoor air temperature and virtual outdoor air humidity acquired as the virtual outdoor air conditions. The first calculation unit 220 calculates (outputs) a first simulation result, which is the result obtained by the simulation calculation. The first calculation unit 220 may include at least one of the injected water temperature, the amount of heat storage, and the power, as the first simulation result obtained by the simulation calculation. The injected water temperature is the temperature of the groundwater injected into the cold water well 22 from the well-side piping 3 that has exchanged heat with the refrigerant circuit 101. The heat storage amount is the amount of energy obtained by injecting water into the cold water well 22 from the well-side piping 3 that has exchanged heat with the refrigerant circuit 101. The power required for heat storage is the power required to operate the pump 31 on the heat source well equipment 10 side, the various pumps (not shown) provided in the refrigerant circuit 101 of the heat storage auxiliary equipment 100, and the cooling tower 130, which are required for storing heat in the first heat storage mode.

[0037] The second calculation unit 230 performs a simulation calculation of a second heat storage mode, including heat storage by the chiller 150 (heat source unit 110 and cooling tower 130), based on the simulation conditions acquired by the acquisition unit 210. The second calculation unit 230 performs a simulation calculation of an operation in a second heat storage mode, including heat storage using the chiller 150, as shown in FIG. 6 , based on the simulation conditions. The second calculation unit 230 performs a simulation calculation of a case in which cold water heat storage is performed in the chilled water well 22 by cooling a medium using the chiller 150. The second calculation unit 230 performs multiple simulation calculations by varying the temperature and humidity within the ranges of the virtual outdoor air temperature and virtual outdoor air humidity acquired as the virtual outdoor air conditions. The second calculation unit 230 calculates (outputs) a second simulation result, which is the result obtained by the simulation calculation. The second calculation unit 230 may calculate at least one of the injected water temperature, the amount of heat storage, and the power as the second simulation result. The second calculation unit 230 may calculate the second simulation result so that the amount of heat stored in the second heat storage mode is the same as the amount of heat stored in the first heat storage mode. The power calculated by the second calculation unit 230 is the power for operating the pump 31 on the heat source well facility 10 side, various pumps (not shown) provided on the refrigerant circuit 101 side of the heat storage auxiliary facility 100, the cooling tower 130, and the heat source unit 110.

[0038] In the first heat storage mode, the temperature calculation unit 240 calculates the limit outside air temperature at which the temperature of the groundwater injected from the well-side pipe 3 into the cold water well 22 after heat exchange with the refrigerant circuit 101 becomes the upper limit injection temperature.

[0039] The determination unit 250 determines one of the first and second heat storage modes based on the first simulation result calculated by the first calculation unit 220 and the second simulation result calculated by the second calculation unit 230. The determination unit 250 may, for example, compare the water supply temperature, heat storage amount, and power included in the first and second simulation results. For example, based on the comparison between the first and second simulation results, the determination unit 250 may determine, for example, the first or second heat storage mode, whichever has a lower water supply temperature, as the heat storage mode. If the determination unit 250 performs a simulation so that the amount of heat storage in the second heat storage mode is the same as the amount of heat storage in the first heat storage mode, the determination unit 250 may determine, for example, the first or second heat storage mode, whichever has a higher heat storage amount, as the heat storage mode. For example, based on the comparison between the first and second simulation results, the determination unit 250 may, for example, determine, for example, the first or second heat storage mode, whichever has a higher heat storage amount, as the heat storage mode. The determination unit 250 may, for example, compare the first simulation result with the second simulation result, for example, compare the power required to store heat in the first heat storage mode with the power required to store heat in the second heat storage mode, and determine the mode with the smaller power as the heat storage mode. When a simulation is performed so that the amount of heat stored in the second heat storage mode is the same as the amount of heat stored in the first heat storage mode, the determination unit 250 may, based on the comparison between the power required to store heat in the first heat storage mode and the power required to store heat in the second heat storage mode, determine the mode with the smaller power as the heat storage mode.

[0040] Furthermore, the determination unit 250 selects the second heat storage mode as the heat storage mode under the condition that the virtual outside air temperature is equal to or higher than the limit outside air temperature calculated by the temperature calculation unit 240. This is because in the first heat storage mode using the cooling tower 130, when the outside air temperature is high, cooling in the cooling tower 130 may be insufficient, causing the water supply temperature to exceed the upper limit water supply temperature. The determination unit 250 may compare the current cold water heat storage amount with a predetermined target cold water heat storage amount (e.g., by predicting that the cold water heat storage amount and the hot water heat storage amount are equal and performing cold water heat storage), and determine the second heat storage mode, which allows for large-capacity cold water heat storage, as the heat storage mode. This is because in the first heat storage mode using the cooling tower 130, a sufficient amount of cold water heat storage may not be obtained.

[0041] The determination unit 250 compares the first simulation result with the second simulation result and generates heat storage mode information that associates the determined heat storage mode, either the first heat storage mode or the second heat storage mode, with each virtual outdoor air condition used in the simulation calculation. The determination unit 250 may generate heat storage mode information that associates the determined heat storage mode with the virtual outdoor air temperature (e.g., in 1°C increments) used in the simulation calculation. The determination unit 250 may generate heat storage mode information that associates the determined heat storage mode with the virtual outdoor air humidity (e.g., in 5% increments) used in the simulation calculation. The determination unit 250 may generate heat storage mode information that associates the determined heat storage mode with each combination of the virtual outdoor air temperature and virtual humidity used in the simulation calculation. The determination unit 250 outputs the generated storage mode information to the control device 300, which will be described later.

[0042] The operation of the computing device 200 of this embodiment will be described. The operation of the computing device 200 corresponds to an embodiment of a computing method. The computing device 200 performs each step shown in FIG.

[0043] First, the acquisition unit 210 acquires simulation conditions (ST01: step of acquiring simulation conditions). The acquisition unit 210 acquires outdoor conditions (outdoor temperature, outdoor humidity) as simulation conditions. For example, the acquisition unit 210 may further acquire a pumping temperature and an upper limit water supply temperature as simulation conditions. For example, the acquisition unit 210 may further acquire the pump 31 of the heat source well facility 10, the heat source unit 110 of the thermal storage auxiliary facility 100, the cooling tower 130, a pump (not shown) provided in the refrigerant circuit 101, specifications of the medium on the thermal storage auxiliary facility 100, etc. as simulation conditions.

[0044] Following the implementation of ST01, the first calculation unit 220 performs a simulation calculation of the first heat storage mode, including heat storage by the cooling tower 130, based on the simulation conditions acquired by the acquisition unit 210, and obtains a first simulation result (ST02: step of performing a simulation calculation in the first heat storage mode).

[0045] Following the implementation of ST02, the second calculation unit 230 performs a simulation calculation of the second heat storage mode, including heat storage by the refrigerator 150, based on the simulation conditions acquired by the acquisition unit 210, and obtains a second simulation result (ST03: step of performing a simulation calculation in the second heat storage mode).

[0046] Following the implementation of ST03, the decision unit 250 compares the power required to store heat in the first heat storage mode with the power required to store heat in the second heat storage mode based on the first simulation result obtained in ST02 and the second simulation result obtained in ST03 (ST04: Step of comparing the power between the first heat storage mode and the second heat storage mode).

[0047] Furthermore, following the execution of ST02, the temperature calculation unit 240 calculates the limit outdoor air temperature at which the temperature of water injected into the cold water well 22 will be the upper limit water injection temperature when heat is stored in the first heat storage mode (ST05: step of calculating the limit outdoor air temperature in the first heat storage mode). ST05 may be performed in parallel with ST04 and ST05, or may be performed before or after ST03 and ST04.

[0048] After completing ST04 and ST05, the determination unit 250 determines either the first heat storage mode or the second heat storage mode based on the first simulation result calculated by the first calculation unit 220 and the second simulation result calculated by the second calculation unit 230 (ST06: step of determining a heat storage mode). The determination unit 250 may compare the water injection temperature, heat storage amount, and power included in the first simulation result and the second simulation result, and determine the heat storage mode so that, for example, energy conservation is increased. The determination unit 250 may select the second heat storage mode as the heat storage mode when the virtual outside air temperature is equal to or higher than the limit outside air temperature, for example, so that the water injection temperature to the cold water well 22 does not exceed the upper limit water injection temperature.

[0049] After performing ST06, the determination unit 250 generates heat storage mode information that associates the determined heat storage mode with each virtual outside air condition (ST07: step of generating heat storage mode information). The determination unit 250 outputs the generated storage mode information to the control device 300.

[0050] (Configuration of control device) As shown in Fig. 2, the control device 300 controls the operation of the geothermal energy utilization system 1. The control device 300 controls the operation of each part of the geothermal energy utilization system 1 in each of the cooling operation mode, the heating operation mode, the first heat storage mode, and the second heat storage mode. When cold water heat storage is performed, the control device 300 operates in the heat storage mode determined by the calculation device 200. Based on the actual outdoor air conditions during operation, the control device 300 operates the geothermal energy utilization system 1 in the heat storage mode corresponding to the actual outdoor air conditions.

[0051] The control device 300 includes a mode information storage unit 310 , an outside air condition acquisition unit 320 , and an operation control unit 330 .

[0052] The mode information storage unit 310 stores the heat storage mode information output from the computing device 200. The mode information storage unit 310 stores the heat storage mode information in which the heat storage mode determined for each computing device 200 and each virtual outside air condition is associated.

[0053] The outdoor air condition acquisition unit 320 acquires actual outdoor air conditions. The outdoor air condition acquisition unit 320 acquires at least one of the actual outdoor air temperature and the actual outdoor air humidity as the actual outdoor air conditions. The outdoor air condition acquisition unit 320 may acquire both the actual outdoor air temperature and the actual outdoor air temperature as the actual outdoor air conditions. The outdoor air condition acquisition unit 320 may acquire, as the actual outdoor air conditions, the actual outdoor air temperature and the actual outdoor air humidity detected by, for example, a thermometer, a hygrometer, or the like at the location where the geothermal utilization system 1 is installed. The outdoor air condition acquisition unit 320 may acquire, for example, the values ​​of the actual outdoor air temperature and the actual outdoor air humidity input by an operator. The outdoor air condition acquisition unit 320 may acquire data on the actual outdoor air temperature and the actual outdoor air humidity via an external network.

[0054] The operation control unit 330 operates the geothermal heat utilization system 1 based on the heat storage mode stored in the mode information storage unit 310. The operation control unit 330 operates the geothermal heat utilization system 1 in either the first heat storage mode or the second heat storage mode based on the heat storage mode stored in the mode information storage unit 310 and the actual outside air conditions. The operation control unit 330 references the heat storage mode information stored in the mode information storage unit 310 and acquires the heat storage mode associated with the virtual outside air conditions corresponding to the acquired actual outside air conditions. The operation control unit 330 controls each unit of the heat source well facility 10 and the heat storage auxiliary facility 100 in the acquired heat storage mode to perform cold water heat storage operation.

[0055] The operation of the control device 300 of this embodiment will be described. The operation of the control device 300 corresponds to an embodiment of a control method. The control device 300 performs each step shown in FIG. 8.

[0056] First, the outside air condition acquisition unit 320 acquires the actual outside air condition (ST11: step of acquiring the actual outside air condition).

[0057] After performing ST11, the operation control unit 330 refers to the heat storage mode information stored in the mode information storage unit 310 and acquires the heat storage mode associated with the virtual outside air condition corresponding to the acquired actual outside air condition (ST12: step of acquiring information on the heat storage mode corresponding to the actual outside air condition). The operation control unit 330 acquires, from the first heat storage mode and the second heat storage mode, the heat storage mode that is determined by the computing device 200 to be appropriate as a result of the comparison under the actual outside air condition at that time.

[0058] After performing ST12, the operation control unit 330 operates the geothermal energy utilization system 1 based on the acquired heat storage mode (ST13: step of operating the geothermal energy utilization system in the acquired heat storage mode). If the operation control unit 330 acquires the first heat storage mode corresponding to the actual outside air conditions, it performs cold water heat storage in the first heat storage mode. If the operation control unit 330 acquires the second heat storage mode corresponding to the actual outside air conditions, it performs cold water heat storage in the second heat storage mode.

[0059] (Actions and Effects) According to this embodiment, the computing device 200 determines the heat storage mode based on the results of a first simulation in which the first heat storage mode, which includes heat storage by the cooling tower 130, is performed, and the results of a second simulation in which the second heat storage mode, which includes heat storage by the chiller 150, is performed. This allows the computing device 200 to determine with high accuracy the heat storage mode that is suitable for the environmental conditions based on the simulation. As a result, the geothermal utilization system 1 can be operated in the heat storage mode that suits the environmental conditions.

[0060] According to one example of this embodiment, the first simulation result and the second simulation result each include at least one of the injected water temperature, the amount of heat storage, and the power. Thus, by comparing at least one of the injected water temperature, the amount of heat storage, and the power between the first heat storage mode including heat storage by the cooling tower 130 and the second heat storage mode including heat storage by the chiller 150, the determination unit 250 can appropriately determine the heat storage mode.

[0061] According to one example of this embodiment, the determination unit 250 compares the power required to store heat in the first heat storage mode with the power required to store heat in the second heat storage mode, thereby enabling the determination unit 250 to select a heat storage mode that requires less power and is more energy-efficient.

[0062] According to one example of this embodiment, the second calculation unit 230 calculates the second simulation result so that the amount of heat storage in the second heat storage mode is the same as the amount of heat storage in the first heat storage mode. As a result, by comparing the first heat storage mode and the second heat storage mode with the same amount of heat storage in the first heat storage mode and the second heat storage mode, the determination unit 250 can select an appropriate heat storage mode.

[0063] According to one example of this embodiment, the determination unit 250 determines either the first heat storage mode or the second heat storage mode in association with each of the plurality of virtual outdoor air conditions. By determining the heat storage mode in association with the virtual outdoor air condition in this way, the geothermal energy utilization system 1 can operate in an appropriate heat storage mode according to the actual outdoor air conditions during operation.

[0064] According to one example of this embodiment, the virtual outdoor air conditions include at least one of a virtual outdoor air temperature and a virtual outdoor air humidity, which allows the geothermal energy utilization system 1 to operate in an appropriate heat storage mode according to the actual outdoor air temperature and humidity during operation.

[0065] According to one example of this embodiment, the determination unit 250 selects the second heat storage mode as the heat storage mode when the virtual outside air temperature is equal to or higher than the limit outside air temperature. As a result, when the actual outside air temperature is high and cooling by the cooling tower 130 would result in a high temperature of the injected water, the geothermal energy utilization system 1 does not use the cooling tower 130 for cooling, but instead stores heat using the refrigerator 150, thereby preventing an increase in the temperature of the injected water.

[0066] According to the calculation method of this embodiment, the heat storage mode is determined based on the results of the first and second simulations, and the heat storage mode suitable for the environmental conditions can be determined with high accuracy based on the simulations. As a result, the geothermal energy utilization system 1 can be operated in the heat storage mode suitable for the environmental conditions.

[0067] According to this embodiment, the control device 300 includes a mode information storage unit 310 that stores heat storage mode information related to the heat storage mode determined by the calculation device 200, and an operation control unit 330 that operates the geothermal heat utilization system 1 based on the heat storage mode stored in the mode information storage unit 310. This enables the geothermal heat utilization system 1 to operate in a heat storage mode that is determined with high accuracy based on simulations performed by the calculation device 200 and is suited to the environmental conditions.

[0068] According to one example of this embodiment, the operation control unit 330 operates the geothermal energy utilization system 1 based on the heat storage mode associated with the actual outdoor air conditions acquired by the outdoor air condition acquisition unit 320. This makes it possible to operate the geothermal energy utilization system 1 in a heat storage mode suited to the environmental conditions, which is determined with high accuracy based on the simulation by the calculation device 200. As a result, the geothermal energy utilization system 1 can be operated in a heat storage mode suited to the environmental conditions.

[0069] According to the control method of this embodiment, it is possible to operate the geothermal energy utilization system 1 in a heat storage mode suited to the environmental conditions, which is determined with high accuracy based on the simulation by the calculation device 200. As a result, it is possible to operate the geothermal energy utilization system 1 in a heat storage mode suited to the environmental conditions.

[0070] <Modifications> In the above-described embodiment, programs for realizing the various functions of the computing device 200 and the control device 300 are recorded on a computer-readable recording medium, and the programs recorded on the recording medium are read into a computer system such as a microcomputer and executed to perform various processes. Here, the various processes of the CPU of the computer system are stored in the form of programs on a computer-readable recording medium, and the various processes are performed by the computer reading and executing the programs. Examples of computer-readable recording media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories. Alternatively, the computer programs may be distributed to computers via communications lines, and the computers that receive the programs may execute the programs.

[0071] In the above-described embodiment, an example of the hardware configuration of the computer 190 that executes programs for realizing the various functions of the calculation device 200 and the control device 300 will be described.

[0072] As shown in FIG. 9 , the computer 190 provided in each of the calculation device 200 and the control device 300 includes a processor 195, a memory 196, a storage / playback device 197, an input output interface (hereinafter referred to as “IO I / F”) 198, and a communication interface (hereinafter referred to as “communication I / F”) 199.

[0073] For example, the processor 195 may be a CPU. For example, the memory 196 may be a medium such as random access memory (hereinafter referred to as "RAM") that temporarily stores data used by programs executed by the computing device 200 and the control device 300. For example, the storage / playback device 197 may be a device for storing data to external media such as CD-ROMs, DVDs, and flash memory, or for playing data from external media. For example, the IO I / F 198 may be an interface for inputting and outputting information between the computing device 200 and the control device 300 and other devices. For example, the communication I / F 199 may be an interface for communicating between the computing device 200 and the control device 300 and other devices via a communication line such as the Internet or a dedicated communication line.

[0074] <Other Embodiments> Although the embodiments of the present disclosure have been described above, these embodiments are provided by way of example only and are not intended to limit the scope of the present disclosure. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the present disclosure. These embodiments and their modifications are considered to be within the scope and spirit of the present disclosure, as well as within the scope of the present disclosure and its equivalents.

[0075] <Additional Notes> The calculation device 200, the calculation method, the program, the control device 300, the control method, and the control program described in the embodiments can be understood, for example, as follows.

[0076] (1) A computing device 200 according to a first aspect is a computing device 200 for determining a heat storage mode when storing heat in a geothermal heat utilization system 1, the computing device 200 including a heat source well facility 10 including a hot water well 21, a cold water well 22, well-side piping 3 connecting the hot water well 21 and the cold water well 22, and a pump 31 provided on the well-side piping 3, and a heat storage auxiliary facility 100 including a cooling tower 130, a chiller 150, and a refrigerant circuit 101 connected to at least one of the cooling tower 130 and the chiller 150 and capable of heat exchange with the well-side piping 3, and the computing device 200 includes an acquisition unit 21 for acquiring simulation conditions. 0, a first calculation unit 220 that calculates a first simulation result that is the result of a simulation of a first heat storage mode including heat storage by the cooling tower 130 based on the simulation conditions, a second calculation unit 230 that calculates a second simulation result that is the result of a simulation of a second heat storage mode including heat storage by the refrigerator 150 based on the simulation conditions, and a determination unit 250 that determines which of the first heat storage mode and the second heat storage mode is the heat storage mode based on the first simulation result and the second simulation result.

[0077] The computing device 200 determines the heat storage mode based on the results of a first simulation in which the first heat storage mode, which includes heat storage by the cooling tower 130, is performed, and the results of a second simulation in which the second heat storage mode, which includes heat storage by the chiller 150, is performed. This allows the computing device 200 to determine with high accuracy the heat storage mode that is suitable for the environmental conditions based on the simulation. As a result, the geothermal utilization system 1 can be operated in the heat storage mode that suits the environmental conditions.

[0078] (2) The computing device 200 according to the second aspect is the computing device 200 of (1), and the first simulation result and the second simulation result may each include at least one of the temperature of water injected from the well-side piping 3 that has exchanged heat with the refrigerant circuit 101 to the cold water well 22, the amount of heat stored on the heat source well equipment 10 side, and the power required to store the heat.

[0079] As a result, by comparing at least one of the water temperature, heat storage amount, and power between the first heat storage mode, which includes heat storage by the cooling tower 130, and the second heat storage mode, which includes heat storage by the refrigerator 150, the determination unit 250 can appropriately determine the heat storage mode.

[0080] (3) The computing device 200 according to a third aspect is the computing device 200 according to (1) or (2), and the determination unit 250 may determine the heat storage mode based on a comparison result between the power required to store heat in the first heat storage mode and the power required to store heat in the second heat storage mode.

[0081] As a result, by comparing the power required to store heat in the first heat storage mode with the power required to store heat in the second heat storage mode, the decision unit 250 can select a heat storage mode that is more energy-efficient.

[0082] (4) The computing device 200 according to the fourth aspect is any one of the computing devices 200 of (1) to (3), and the second calculation unit 230 may calculate the second simulation result so that the amount of heat stored in the second heat storage mode is the same as the amount of heat stored in the first heat storage mode.

[0083] This allows the determination unit 250 to select an appropriate heat storage mode by comparing the first heat storage mode and the second heat storage mode while maintaining the same amount of heat storage in the first heat storage mode and the second heat storage mode.

[0084] (5) The computing device 200 according to the fifth aspect is any one of the computing devices 200 of (1) to (4), and the determination unit 250 may determine one of the first heat storage mode and the second heat storage mode in association with each virtual outdoor air condition of a plurality of virtual outdoor air conditions.

[0085] As a result, by determining the heat storage mode in association with the virtual outside air conditions, the geothermal energy utilization system 1 can operate in an appropriate heat storage mode according to the actual outside air conditions during operation.

[0086] (6) A computing device 200 according to a sixth aspect is the computing device 200 of (5), wherein the virtual outside air conditions may include at least one of a virtual outside air temperature and a virtual outside air humidity.

[0087] This allows the geothermal energy utilization system 1 to operate in an appropriate heat storage mode according to the actual outside air temperature and the actual outside air temperature during operation.

[0088] (7) The computing device 200 according to a seventh aspect is the computing device 200 of (5) or (6), and further includes a temperature calculation unit 240 that calculates a limit outside air temperature at which the temperature of water injected from the well side piping 3 that has exchanged heat with the refrigerant circuit 101 to the cold water well 22 becomes an upper limit water injection temperature in the first heat storage mode, and the determination unit 250 may select the second heat storage mode as the heat storage mode when the virtual outside air temperature is equal to or higher than the limit outside air temperature.

[0089] As a result, when the virtual outside air temperature is such that the water injection temperature is equal to or higher than the upper limit water injection temperature, the second heat storage mode is selected as the heat storage mode. In the case where the actual outside air temperature is high and cooling using the cooling tower 130 would result in a high water injection temperature, the geothermal energy utilization system 1 can suppress the rise in water injection temperature by storing heat using the refrigerator 150 instead of cooling using the cooling tower 130.

[0090] (8) A calculation method according to an eighth aspect is a calculation method for determining a heat storage mode when storing heat in a geothermal utilization system 1 that includes a heat source well facility 10 including a hot water well 21, a cold water well 22, well-side piping 3 connecting the hot water well 21 and the cold water well 22, and a pump 31 provided on the well-side piping 3, and a heat storage auxiliary facility 100 that includes a cooling tower 130, a chiller 150, and a refrigerant circuit 101 that is connected to at least one of the cooling tower 130 and the chiller 150 and is capable of heat exchange with the well-side piping 3, the calculation method comprising the steps of: acquiring simulation conditions; calculating a first simulation result based on the simulation conditions, which is the result of a simulation of a first heat storage mode including heat storage by the cooling tower 130; calculating a second simulation result based on the simulation conditions, which is the result of a simulation of a second heat storage mode including heat storage by the chiller 150; and determining one of the first heat storage mode and the second heat storage mode based on the first simulation result and the second simulation result.

[0091] Thus, by determining the heat storage mode based on the results of the first and second simulations, the heat storage mode suitable for the environmental conditions can be determined with high accuracy based on the simulations, and as a result, the geothermal energy utilization system 1 can be operated in the heat storage mode suitable for the environmental conditions.

[0092] (9) A program according to a ninth aspect is a method for determining a heat storage mode when storing heat in a geothermal utilization system 1 including a heat source well facility 10 including a hot water well 21, a cold water well 22, well-side piping 3 connecting the hot water well 21 and the cold water well 22, and a pump 31 provided on the well-side piping 3, and a heat storage auxiliary facility 100 including a cooling tower 130, a chiller 150, and a refrigerant circuit 101 connected to at least one of the cooling tower 130 and the chiller 150 and capable of heat exchange with the well-side piping 3, the program acquiring simulation conditions, calculating a first simulation result based on the simulation conditions, which is the result of a simulation of a first heat storage mode including heat storage by the cooling tower 130, calculating a second simulation result based on the simulation conditions, which is the result of a simulation of a second heat storage mode including heat storage by the chiller 150, and determining either the first heat storage mode or the second heat storage mode based on the first simulation result and the second simulation result, and causing a computer to execute the method.

[0093] Thus, by determining the heat storage mode based on the results of the first and second simulations, the heat storage mode suitable for the environmental conditions can be determined with high accuracy based on the simulations, and as a result, the geothermal energy utilization system 1 can be operated in the heat storage mode suitable for the environmental conditions.

[0094] (10) The control device 300 according to the tenth aspect includes a mode information storage unit 310 storing heat storage mode information regarding the heat storage mode determined by any one of the computing devices 200 of (1) to (7), and an operation control unit 330 that operates the geothermal energy utilization system 1 based on the heat storage mode stored in the mode information storage unit 310.

[0095] This allows the geothermal energy utilization system 1 to operate in a heat storage mode that is determined with high accuracy based on simulations by the calculation device 200 and is suited to the environmental conditions.

[0096] (11) The control device 300 relating to the 11th aspect is the control device 300 of (10), and is equipped with an outdoor air condition acquisition unit 320 that acquires actual outdoor air conditions, and the operation control unit 330 may operate the geothermal energy utilization system 1 based on the heat storage mode associated with the actual outdoor air conditions acquired by the outdoor air condition acquisition unit 320.

[0097] This allows the geothermal utilization system 1 to be operated in a heat storage mode suited to the environmental conditions, which is determined with high accuracy based on the simulation by the calculation device 200. As a result, the geothermal utilization system 1 can be operated in a heat storage mode suited to the environmental conditions.

[0098] (12) The control method according to the twelfth aspect stores heat storage mode information regarding the heat storage mode determined by any one of the computing devices 200 of (1) to (7), and operates the geothermal energy utilization system 1 based on the stored heat storage mode.

[0099] This allows the geothermal utilization system 1 to be operated in a heat storage mode suited to the environmental conditions, which is determined with high accuracy based on the simulation by the calculation device 200. As a result, the geothermal utilization system 1 can be operated in a heat storage mode suited to the environmental conditions.

[0100] (13) The control program according to the thirteenth aspect stores heat storage mode information regarding the heat storage mode determined by any one of the computing devices 200 of (1) to (7), and causes the computer to execute a method of operating the geothermal energy utilization system 1 based on the stored heat storage mode.

[0101] This allows the geothermal utilization system 1 to be operated in a heat storage mode suited to the environmental conditions, which is determined with high accuracy based on the simulation by the calculation device 200. As a result, the geothermal utilization system 1 can be operated in a heat storage mode suited to the environmental conditions.

[0102] DESCRIPTION OF SYMBOLS 1... Geothermal heat utilization system 2... Well 3... Well-side piping 4... Heat exchanger 10... Heat source well equipment 21... Hot water well 22... Cold water well 31... Pump 100... Thermal storage auxiliary equipment 101... Refrigerant circuit 110... Heat source unit 120... Air conditioner 130... Cooling tower 140... Second heat exchanger 150... Refrigerator 190... Computer 195... Processor 196... Memory 197... Recording / playback device 198... IO I / F 199... Communication I / F 200... Calculation device 210... Acquisition unit 220... First calculation unit 230... Second calculation unit 240... Temperature calculation unit 250... Determination unit 300... Control device 310... Mode information storage unit 320... Outdoor air condition acquisition unit 330... Operation control unit ST01... Step of acquiring simulation conditions ST02...Step of performing a simulation calculation in the first heat storage mode ST03...Step of performing a simulation calculation in the second heat storage mode ST04...Step of comparing the power of the first heat storage mode and the second heat storage mode ST05...Step of calculating the limit outdoor air temperature in the first heat storage mode ST06...Step of determining the heat storage mode ST07...Step of generating heat storage mode information ST11...Step of acquiring actual outdoor air conditions ST12...Step of acquiring the heat storage mode corresponding to the actual outdoor air conditions ST13...Step of operating the geothermal energy utilization system in the acquired heat storage mode

Claims

1. A calculation device for determining a heat storage mode when storing heat in a geothermal energy utilization system including a heat source well facility having a hot water well, a cold water well, well-side piping connecting the hot water well and the cold water well, and a pump installed on the well-side piping, and a heat storage auxiliary facility having a cooling tower, a chiller, and a refrigerant circuit connected to at least one of the cooling tower and the chiller and capable of heat exchange with the well-side piping, the calculation device comprising: an acquisition unit for acquiring simulation conditions; a first calculation unit for calculating a first simulation result that is the result of a simulation of a first heat storage mode including heat storage by the cooling tower based on the simulation conditions; a second calculation unit for calculating a second simulation result that is the result of a simulation of a second heat storage mode including heat storage by the chiller based on the simulation conditions; and a determination unit for determining either the first heat storage mode or the second heat storage mode based on the first simulation result and the second simulation result.

2. The calculation device of claim 1, wherein the first simulation result and the second simulation result each include at least one of the following: the temperature of the water injected from the well-side piping that has exchanged heat with the refrigerant circuit to the cold water well; the amount of heat stored on the heat source well equipment side; and the power required to store the heat.

3. The computing device according to claim 1 or 2, wherein the determination unit determines the heat storage mode based on a comparison result between the power required to store heat in the first heat storage mode and the power required to store heat in the second heat storage mode.

4. The calculation device according to any one of claims 1 to 3, wherein the second calculation unit calculates the second simulation result so that the amount of heat stored in the second heat storage mode is the same as the amount of heat stored in the first heat storage mode.

5. The computing device according to any one of claims 1 to 4, wherein the determination unit determines one of the first heat storage mode and the second heat storage mode in association with each virtual outdoor air condition of a plurality of virtual outdoor air conditions.

6. The computing device of claim 5, wherein the virtual outdoor conditions include at least one of a virtual outdoor temperature and a virtual outdoor humidity.

7. The computing device according to claim 6, further comprising a temperature calculation unit that calculates a limit outside air temperature at which the temperature of water injected from the well-side piping that has exchanged heat with the refrigerant circuit to the cold water well becomes an upper limit water injection temperature in the first heat storage mode, and the determination unit selects the second heat storage mode as the heat storage mode when the virtual outside air temperature is equal to or higher than the limit outside air temperature.

8. A calculation method for determining a heat storage mode when storing heat in a geothermal energy utilization system comprising: a heat source well facility including a hot water well, a cold water well, well-side piping connecting the hot water well and the cold water well, and a pump installed on the well-side piping; and a heat storage auxiliary facility having a cooling tower, a chiller, and a refrigerant circuit connected to at least one of the cooling tower and the chiller and capable of heat exchange with the well-side piping, the calculation method comprising: acquiring simulation conditions; calculating a first simulation result based on the simulation conditions, which is the result of a simulation of a first heat storage mode including heat storage by the cooling tower; calculating a second simulation result based on the simulation conditions, which is the result of a simulation of a second heat storage mode including heat storage by the chiller; and determining either the first heat storage mode or the second heat storage mode based on the first simulation result and the second simulation result.

9. A method for determining a heat storage mode when storing heat in a geothermal energy utilization system comprising: a heat source well facility including a hot water well, a cold water well, well-side piping connecting the hot water well and the cold water well, and a pump installed on the well-side piping; and a heat storage auxiliary facility having a cooling tower, a chiller, and a refrigerant circuit connected to at least one of the cooling tower and the chiller and capable of heat exchange with the well-side piping, the method comprising: acquiring simulation conditions; calculating a first simulation result based on the simulation conditions, which is the result of a simulation of a first heat storage mode including heat storage by the cooling tower; calculating a second simulation result based on the simulation conditions, which is the result of a simulation of a second heat storage mode including heat storage by the chiller; and determining either the first heat storage mode or the second heat storage mode based on the first simulation result and the second simulation result.

10. A control device comprising: a mode information storage unit that stores heat storage mode information regarding the heat storage mode determined by the calculation device according to any one of claims 1 to 7; and an operation control unit that operates the geothermal heat utilization system based on the heat storage mode stored in the mode information storage unit.

11. A control device as described in claim 10, further comprising an outdoor air condition acquisition unit that acquires actual outdoor air conditions, and wherein the operation control unit operates the geothermal energy utilization system based on the heat storage mode associated with the actual outdoor air conditions acquired by the outdoor air condition acquisition unit.

12. A control method for storing heat storage mode information regarding the heat storage mode determined by the calculation device according to any one of claims 1 to 7, and operating the geothermal heat utilization system based on the stored heat storage mode.

13. A control program for causing a computer to execute a method of storing heat storage mode information regarding the heat storage mode determined by the calculation device according to any one of claims 1 to 7, and operating the geothermal heat utilization system based on the stored heat storage mode.