Heat accumulation system

Abstract

To provide a heat accumulation system which can constantly secure emergency cold heat in heat accumulation tanks.SOLUTION: A heat accumulation system 10 comprises a plurality of heat accumulation tanks 11 for accumulating cold heat. Each of the heat accumulation tanks 11 is transited between a standby state that the cold heat is accumulated to a set calorie or higher, and a heat radiation state that the accumulated cold heat is lower than the set calorie. When at least one heat accumulation tank 11 is in a standby state, the heat accumulation system 10 performs heat accumulation processing for accumulating the cold heat up to the set calorie or higher in the other heat-radiated state heat accumulation tank 11. Also, when a cooling part 3 for supplying the cold heat to an air conditioner 2 is stopped in an operation, the heat accumulation system 10 performs cold heat supplement processing for supplying the cold heat to the air conditioner 2 from the standby-state heat accumulation tank 11.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a thermal storage system. [Background technology]

[0002] In data centers that have server rooms containing many servers, the amount of heat emitted from the servers and other electronic devices is large, so air conditioners are operated constantly to keep room temperatures from rising. Data centers are equipped with uninterruptible power supplies (UPS) and generators as emergency power sources for the servers and air conditioners in the event of a power outage. In the event of a commercial power outage, the servers and air conditioners run on power supplied from the uninterruptible power supply. In addition, in the event of a power outage, chillers that supply cold to the air conditioners run on power supplied from the generator.

[0003] A generator used as an emergency power source may take a long time to start up (for example, several minutes). In a data center, the rise in room temperature from when the generator is started until the refrigerator is operating stably may not be negligible. For this reason, a technology is known that uses a heat storage tank as a cooling source for server rooms and the like (see, for example, Patent Document 1). The heat storage tank has a heat medium such as water that stores cold energy. In the event of a power outage, the rise in room temperature is suppressed by using the cold energy that was stored in the heat medium of the heat storage tank before the power outage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-70579 A Summary of the Invention [Problem to be solved by the invention]

[0005] The cold energy stored in the heat storage tank leaks over time. If the heat storage tank does not store enough cold energy due to the leakage of cold energy, it may not be possible to sufficiently suppress the rise in room temperature in an emergency. [Means for solving the problem]

[0006] The heat storage system that solves the above problem includes a plurality of heat storage tanks that store cold heat, and each heat storage tank transitions between a standby state in which cold heat is stored up to a set heat amount or more, and a heat dissipation state in which the stored cold heat is less than the set heat amount, and when at least one heat storage tank is in the standby state, a heat storage process is performed in which cold heat is stored in other heat storage tanks in the heat dissipation state up to the set heat amount or more, and when a cooling unit that supplies cold heat to an air conditioner stops, a cold heat compensation process is performed in which cold heat is supplied to the air conditioner from the heat storage tank in the standby state. Effect of the Invention

[0007] According to the present invention, cold energy for emergencies can be constantly secured in the heat storage tank. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of an air conditioning system equipped with a heat storage system. [Diagram 2] FIG. 2 is a table showing a time table in which the timings of storing and discharging heat in each heat storage tank in the heat storage system are set during normal times. [Diagram 3] FIG. 3 is a schematic diagram of the air conditioning system when performing a heat storage process for storing cold heat in the first heat storage tank during normal times. [Figure 4] FIG. 4 is a schematic diagram of the air conditioning system when performing a heat dissipation process for supplying cold heat from the second heat storage tank to the air conditioner during normal operation. [Diagram 5] FIG. 5 is a schematic diagram of the air conditioning system when performing a heat storage process for storing cold heat in the second heat storage tank during normal times. [Figure 6] FIG. 6 is a schematic diagram of the air conditioning system when performing a heat dissipation process for supplying cold heat from the first heat storage tank to the air conditioner during normal operation. [Figure 7] FIG. 7 is a schematic diagram of the air conditioning system when performing cold heat compensation processing for supplying cold heat from the first heat storage tank to the air conditioner during a power outage. [Figure 8]FIG. 8 is a schematic diagram of an air conditioning system when performing makeup water replenishment processing to supply water from the second heat storage tank to the cooling tower during a water outage. [Figure 9] FIG. 9 is a schematic diagram of an air conditioning system when cold heat replenishment processing and makeup water replenishment processing are performed in parallel during a power outage and water outage. [Figure 10] FIG. 10 is a table showing an example of a modified time table in which the timings of storing and discharging heat in each heat storage tank in the heat storage system are set. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Overall configuration] An embodiment of a heat storage system will be described with reference to Figs. 1 to 10. As shown in FIG. 1, a thermal storage system 10 is incorporated into an air conditioning system 1. The air conditioning system 1 is responsible for conditioning an indoor space to be cooled. One example of the space to be cooled is a server room in a data center in which a large number of network devices such as servers are installed. The air conditioning system 1 is provided with an emergency power supply, which is a backup power supply to be used in the event of a power outage, in addition to a commercial power supply under normal circumstances. For example, the air conditioning system 1 is provided with an uninterruptible power supply (UPS) and a generator as the emergency power supply.

[0010] The air conditioning system 1 includes an air conditioner 2 and a cooling unit 3. The air conditioner 2 is responsible for conditioning the space to be cooled. The cooling unit 3 supplies cold heat to the air conditioner 2. The cooling unit 3 is, for example, a compression type refrigerator. The air conditioner 2 cools the air using the cold heat supplied from the cooling unit 3, and sends the cooled air to the space to be cooled as cold air. In this way, the air conditioning system 1 suppresses a temperature rise in the space to be cooled due to exhaust heat from devices and the like arranged in the space to be cooled.

[0011] In the figure, arrows connecting the components of the air conditioning system 1 indicate paths along which cold energy is transferred. Solid arrows indicate a state in which cold energy is being transferred. Dashed arrows indicate a state in which cold energy is not being transferred.

[0012] For example, the cooling unit 3 includes a circuit including an evaporator, a compressor, a condenser, and an expansion valve, and a first refrigerant circulating through the circuit. In the evaporator of the cooling unit 3, the second refrigerant circulating between the air conditioner 2 and the cooling unit 3 is cooled by the first refrigerant. Then, the second refrigerant cooled by the evaporator of the cooling unit 3 is supplied to a first coil included in the air conditioner 2, whereby air to be turned into cold air is cooled in the first coil.

[0013] The air conditioning system 1 includes a cooling tower 4. The cooling tower 4 supplies cold heat to the cooling unit 3 via cooling water circulating between the cooling unit 3 and the cooling tower 4. The cooling water recovers heat from a first refrigerant circulating through the cooling unit 3 in a condenser of the cooling unit 3, and is cooled by outside air in the cooling tower 4. In other words, the cooling tower 4 dissipates the heat recovered from the cooling unit 3 via the cooling water to the outside.

[0014] A makeup water pipe 4A for supplying makeup water W1 is connected to the cooling tower 4. In the cooling tower 4, the makeup water W1 is mixed with the cooling water as circulating water to replenish the cooling water lost due to evaporation for cooling. The makeup water W1 is constantly supplied to the cooling tower 4 from, for example, a water supply through the makeup water pipe 4A.

[0015] [Heat storage system] The heat storage system 10 includes a first heat storage tank 11A, a second heat storage tank 11B, and a refrigerator 12. In the following description, when there is no need to distinguish between the first heat storage tank 11A and the second heat storage tank 11B, they will simply be referred to as heat storage tanks 11.

[0016] The heat storage tank 11 contains water W2 as a heat medium. The refrigerator 12 supplies cold energy to the first heat storage tank 11A and the second heat storage tank 11B separately. The heat storage tank 11 stores the cold energy supplied from the refrigerator 12 in the water W2.

[0017] The heat storage system 10 is configured so that the cold energy stored in the first heat storage tank 11A and the second heat storage tank 11B can be supplied to the air conditioner 2 via the heat exchanger 13. For example, in the heat exchanger 13, a third refrigerant circulating between the air conditioner 2 and the heat exchanger 13 is cooled using the cold energy stored in either the first heat storage tank 11A or the second heat storage tank 11B. Then, by supplying the third refrigerant cooled in the heat exchanger 13 to a second coil included in the air conditioner 2, the air to be turned into cold air is cooled in the second coil.

[0018] For example, when the entire air conditioning system 1 stops due to a power outage or the like, the heat storage tank 11 supplies cold energy to the air conditioner 2 from when the air conditioning system 1 is restored by the emergency power source until the operation of the cooling unit 3 stabilizes. In other words, when the cooling unit 3 stops due to a power outage or the like, the cold energy stored in the heat storage tank 11 is used as an emergency cooling source until the cooling unit 3 can output at its rated capacity due to the emergency power source.

[0019] The cold energy stored in the heat storage tank 11 leaks over time. Therefore, in the heat storage system 10, even during normal operation, the cold energy stored in the heat storage tank 11 is supplied to the air conditioner 2 according to a time schedule described below. During normal operation, the cold energy stored in the heat storage tank 11 is not simply leaked over time, but is instead radiated to the air conditioner 2 and used for cooling, thereby improving the energy efficiency of the air conditioning system 1.

[0020] Furthermore, in the heat storage system 10, at least one heat storage tank 11 is configured to be in a standby state in which cold energy equal to or greater than a set amount of heat is stored during normal operation. The set amount of heat is the amount of cold energy required to cool the air conditioner 2 when the cooling unit 3 stops due to a power outage or the like, until the cooling unit 3 is able to output at rated capacity again through an emergency power source. Each heat storage tank 11 transitions between a standby state and a heat dissipation state in which the stored cold energy is less than the set amount of heat.

[0021] The heat storage system 10 includes a first water supply pipe 14 and a second water supply pipe 15. The heat storage system 10 is configured to be able to supply water W2 from the first heat storage tank 11A to the cooling tower 4 via the first water supply pipe 14. The heat storage system 10 is also configured to be able to supply water W2 from the second heat storage tank 11B to the cooling tower 4 via the second water supply pipe 15.

[0022] A first gate valve 14A is provided in the first water supply pipe 14. A second gate valve 15A is provided in the second water supply pipe 15. In the drawings, the first gate valve 14A and the second gate valve 15A are shown in black when closed, and the first gate valve 14A and the second gate valve 15A are shown in white when open.

[0023] In the heat storage system 10, when the supply of makeup water W1 to the cooling tower 4 is cut off due to, for example, a water outage, the water W2 from the heat storage tank 11 is supplied to the cooling tower 4 through the first water supply pipe 14 or the second water supply pipe 15. As a result, the cooling water circulating between the cooling unit 3 and the cooling tower 4 is replenished with the water W2 from the heat storage tank 11 until the water outage is restored.

[0024] The thermal storage system 10 includes a control device 20. The control device 20 includes a control unit 21 and a storage unit 22. The control unit 21 includes a processor that executes various processes by software, such as a CPU or an MPU. The storage unit 22 includes a temporary memory and a non-volatile memory. The temporary memory is, for example, a RAM. The non-volatile memory is, for example, a flash memory, an HDD, or an SSD.

[0025] The control unit 21 controls the operation of each unit included in the heat storage system 10. For example, the control unit 21 controls the operation of the refrigerator 12 to store cold heat in the first heat storage tank 11A and the second heat storage tank 11B separately. For example, the control unit 21 controls a pump or the like to circulate the water W2 storing cold heat between the heat storage tank 11 and the heat exchanger 13, and also circulates the third refrigerant between the air conditioner 2 and the heat exchanger 13. As a result, the cold heat stored in the heat storage tank 11 is supplied to the air conditioner 2 via the heat exchanger 13 during normal times and during emergencies. In addition, for example, the control unit 21 controls the pump, the first gate valve 14A, the second gate valve 15A, and the like to supply the water W2 in the heat storage tank 11 to the cooling tower 4.

[0026] The control unit 21 may control operations of the air conditioning system 1 other than the heat storage system 10. For example, the control unit 21 controls the operations of the air conditioner 2, the cooling unit 3, and the cooling tower 4 to blow cool air into the space to be cooled.

[0027] [Control form of heat storage system under normal conditions] 2 to 6, a control form of the heat storage system 10 in normal times when no abnormality such as a power outage or water outage occurs will be described. In normal times, the control unit 21 controls the operation of each part of the heat storage system 10 so as to store heat in each heat storage tank 11 and release heat from each heat storage tank 11 based on a time schedule stored in the memory unit 22.

[0028] 2, time table 100 is an example of a time schedule stored in storage unit 22. In time table 100, for example, one cycle is every two days, and an operation pattern including heat storage in each heat storage tank 11 and heat release from each heat storage tank 11 is repeated. That is, based on time table 100, control unit 21 executes a process of storing or releasing heat in heat storage tank 11 in the following order: nighttime on the first day, daytime on the first day, nighttime on the second day, and daytime on the second day, and then, from the third day onwards, executes the same process again in the following order starting from the first day.

[0029] In timetable 100, nighttime includes a time period when there is less demand for commercial power than during the day, such as late night hours. As an example, in timetable 100, nighttime is between 9 PM and 7 AM, and daytime is between 7 AM and 9 PM.

[0030] In the timetable 100, the timing of each process is set so that while one heat storage tank 11 is in a standby state, a heat dissipation process is performed to supply cold heat from the other heat storage tank 11 to the air conditioner 2, and then a heat storage process is performed to store the cold heat in the other heat storage tank 11 in a heat dissipation state.

[0031] 3 to 6, the control mode of heat storage system 10 will be described for each timing of time table 100. For ease of explanation, in Fig. 3 to Fig. 9, the outer shape of heat storage tank 11 in the standby state is shown by a thick line, and the outer shape of heat storage tank 11 in the heat dissipation state is shown by a thin line.

[0032] 3, during the night of the first day, the control unit 21 controls the refrigerator 12 to perform a heat storage process to store cold energy in the first heat storage tank 11A in a heat dissipation state up to a set heat amount or more. The second heat storage tank 11B is maintained in a standby state without storing or dissipating heat, except for leakage of cold energy over time. The first heat storage tank 11A then goes into a standby state after the heat storage process is completed.

[0033] 4, during the day on the first day, the control unit 21 performs a heat dissipation process to supply the remaining amount of cold energy stored in the second heat storage tank 11B to the air conditioner 2. This causes the second heat storage tank 11B to enter a heat dissipation state. The first heat storage tank 11A is maintained in a standby state.

[0034] 5, during the night of the second day, the control unit 21 controls the refrigerator 12 to perform a heat storage process for storing cold heat in the second heat storage tank 11B in a heat dissipation state up to a set heat amount or more. The first heat storage tank 11A is maintained in a standby state. After the heat storage process is completed, the second heat storage tank 11B enters a standby state.

[0035] As shown in Fig. 6, during the day on the second day, the control unit 21 performs a heat dissipation process to supply the remaining amount of cold energy stored in the first heat storage tank 11A to the air conditioner 2. As a result, the first heat storage tank 11A enters a heat dissipation state. The second heat storage tank 11B is maintained in a standby state. Thereafter, the control unit 21 stores and dissipates heat in the first heat storage tank 11A and the second heat storage tank 11B by repeating the controls of Figs. 3 to 6.

[0036] The heat storage process and the heat dissipation process are performed at any timing within a time period defined by the timetable 100, such as nighttime or daytime. Therefore, for example, both the first heat storage tank 11A and the second heat storage tank 11B may be in a standby state during the period from when the heat storage in the first heat storage tank 11A is completed during the nighttime on the first day until the heat dissipation in the second heat storage tank 11B starts during the daytime on the first day.

[0037] [Emergency heat storage system control] Next, a control mode of the heat storage system 10 in an emergency when an abnormality such as a power outage or water outage occurs will be described with reference to Fig. 7 to Fig. 9. Note that, as an example, a case where an abnormality such as a power outage or water outage occurs during the nighttime state of the second day (see Fig. 5) when the first heat storage tank 11A is in a standby state and the second heat storage tank 11B is in a heat dissipation state before the heat storage process will be described.

[0038] First, the control mode of the heat storage system 10 during a power outage will be described with reference to Fig. 7. When power supply from a commercial power source to the air conditioning system 1 is stopped due to a power outage, the air conditioning system 1 is immediately restored by the emergency power source. For example, during a power outage, the air conditioner 2 and the control device 20 are operated by power supply from an uninterruptible power supply. Also, during a power outage, the cooling unit 3 is operated by power supply from a generator.

[0039] 7, in the event of a power outage during the night of the second day, when the air conditioning system 1 is restored by the emergency power supply, the control unit 21 performs a cold energy compensation process by supplying the cold energy stored in the first heat storage tank 11A in a standby state to the air conditioner 2. As a result, the cold energy stored in the first heat storage tank 11A is used to cool the space to be cooled until the operation of the cooling unit 3 becomes stable.

[0040] Next, a control form of the heat storage system 10 when the supply of makeup water W1 to the cooling tower 4 is cut off due to a water outage or the like will be described with reference to Fig. 8. In Fig. 8, the makeup water pipe 4A is shown by a dashed line to indicate that the supply of makeup water W1 to the cooling tower 4 is cut off.

[0041] When the supply of makeup water W1 to the cooling tower 4 is cut off due to a water outage or the like, the control unit 21 detects that the supply of makeup water W1 to the cooling tower 4 has been cut off by a flow meter or the like provided in the makeup water pipe 4A. In this case, the control unit 21 performs a makeup water replenishment process to supply water W2 from the heat storage tank 11 to the cooling tower 4.

[0042] As shown in Fig. 8, when a water outage occurs during the night of the second day, the control unit 21 performs a make-up water replenishment process to supply water W2 to the cooling tower 4 not from the first heat storage tank 11A in a standby state, but from the second heat storage tank 11B in a heat dissipation state before the heat storage process is performed. As a result, the cooling water circulating between the cooling unit 3 and the cooling tower 4 is replenished with water W2 from the second heat storage tank 11B until the supply of make-up water W1 to the cooling tower 4 is resumed. In Fig. 8, the second gate valve 15A is shown in white to indicate that the second gate valve 15A is open.

[0043] In the makeup water replenishment process, when one heat storage tank 11 is in a standby state, water W2 may be supplied to the cooling tower 4 from the other heat storage tank 11. That is, in the makeup water replenishment process, when one heat storage tank 11 is in a standby state, the state of the other heat storage tank 11 that supplies water W2 to the cooling tower 4 is not limited. The heat storage tank 11 that supplies water W2 to the cooling tower 4 may be, for example, in a state before heat storage treatment or heat dissipation treatment is performed, in a state where heat storage treatment or heat dissipation treatment is performed, or in a state after heat storage treatment or heat dissipation treatment is performed.

[0044] Next, a control form of the heat storage system 10 when a power outage occurs and the supply of makeup water W1 to the cooling tower 4 is cut off will be described with reference to Fig. 9. When the air conditioning system 1 stops due to a power outage and the supply of makeup water W1 to the cooling tower 4 is cut off due to a water outage or the like, when the air conditioning system 1 is restored by an emergency power source, the control unit 21 performs cold heat replenishment processing and makeup water replenishment processing in parallel.

[0045] 9, when a power outage and water outage occur during the night of the second day, the control unit 21 performs a cold heat compensation process by supplying the cold heat stored in the first heat storage tank 11A in a standby state to the air conditioner 2. Then, the control unit 21 performs a makeup water compensation process by supplying water W2 to the cooling tower 4 from the second heat storage tank 11B in a heat dissipation state before the heat storage process is performed.

[0046] [Operation of the embodiment] The heat storage system 10 performs a heat storage process in which one heat storage tank 11 is stored with cold energy while the other heat storage tank 11 is in a standby state. As a result, in the heat storage system 10, at any one of the heat storage tanks 11, cold energy equal to or greater than a set amount of heat is always stored during normal operation.

[0047] [Effects of the embodiment] According to the above embodiment, the following effects can be obtained. (1) In the heat storage system 10, when one of the heat storage tanks 11 is in a standby state, a heat storage process is performed to store cold energy in the other heat storage tank 11, so that at normal times, one of the heat storage tanks 11 always stores a set amount of cold energy or more. This makes it possible to always secure cold energy for emergencies.

[0048] (2) In the heat storage system 10, when one of the heat storage tanks 11 is in a standby state, the control unit 21 performs a heat dissipation process to supply cold heat from the other heat storage tank 11 to the air conditioner 2, and then performs a heat storage process to store the cold heat in the other heat storage tank 11. By performing the heat dissipation process, the cold heat stored in the heat storage tank 11 can be effectively used for cooling the air conditioner 2, rather than simply leaking over time. In addition, by performing the heat storage process after the heat dissipation process, heat storage can be started when the amount of stored heat in the heat storage tank 11 is small, and the temperature profile of the heat storage tank 11 becomes good. As a result, the efficiency of heat storage in the heat storage tank 11 can be improved.

[0049] (3) The heat storage system 10 can contribute to leveling out the power consumption of commercial power sources by performing heat storage at night when the power demand from commercial power sources is relatively low, and heat dissipation during the day when the power demand from commercial power sources is relatively high. In addition, when electricity rates are set according to the power demand from commercial power sources, such as nighttime electricity rates, this can also reduce electricity rates.

[0050] (4) When the supply of makeup water W1 to the cooling tower 4 is cut off, makeup water replenishment processing is performed to supply water W2 from the heat storage tank 11 to the cooling tower 4, thereby making it possible to replenish the cooling water circulating between the cooling unit 3 and the cooling tower 4. In addition, by supplying water W2 from another heat storage tank 11 to the cooling tower 4 while a standby heat storage tank 11 is secured, it is possible to perform cold heat replenishment processing using the standby heat storage tank 11 after makeup water replenishment processing has been performed.

[0051] [Example of change] The above embodiment can be modified as follows. The modifications can be combined as appropriate within the scope of the present invention.

[0052] For example, in the air conditioning system 1, if a water tank for backing up make-up water W1 in the event of a water outage is provided in addition to the heat storage system 10, the make-up water replenishment process may not be performed. In this case, the configuration for performing the make-up water replenishment process in the first water supply pipe 14, the second water supply pipe 15, etc. may be omitted.

[0053] In the timetable 100, the time period during which the heat storage process is performed does not have to be at night as long as the power demand from the commercial power source is relatively low. Similarly, the time period during which the heat dissipation process is performed does not have to be at night as long as the power demand from the commercial power source is relatively high. Furthermore, the heat storage process and the heat dissipation process may be performed at any time period, regardless of the power demand from the commercial power source.

[0054] The heat dissipation process during normal times may be omitted. In this case, the cold stored in the heat storage tank 11 is stored by the heat storage process in an amount equal to the amount of cold that has leaked over time. Therefore, the frequency of the heat storage process can be reduced.

[0055] In the timetable 100, an example has been given in which a day is divided into two time periods, night and day, but this is not limited to this. For example, a day may be divided into three or more time periods, or may be divided into periods of one day or several days.

[0056] The heat storage system 10 may include three or more heat storage tanks 11. For example, the heat storage system 10 may include two or more first heat storage tanks 11A, or may include two or more second heat storage tanks 11B.

[0057] 10, the heat storage system 10 may include a third heat storage tank in addition to the first heat storage tank 11A and the second heat storage tank 11B. A time table 200 shown in Fig. 10 is an example of a time schedule stored in the storage unit 22. In the time table 200, the timing of each process is set so that, while at least one heat storage tank 11 is in a standby state, a heat dissipation process is performed to supply cold heat from the other heat storage tank 11 to the air conditioner 2, and then a heat storage process is performed to store the cold heat in the other heat storage tank 11.

[0058] [Note] According to the above embodiment and its modifications, the following technical ideas can be derived. (Appendix 1) An air conditioner that blows cool air into a space to be cooled; A cooling unit that supplies cold heat to the air conditioner; A plurality of heat storage tanks for storing cold heat; Each heat storage tank transitions between a standby state in which cold energy is stored to a set amount or more and a heat dissipation state in which the stored cold energy is less than the set amount, When at least one of the heat storage tanks is in the standby state, a heat storage process is performed to store cold heat in the other heat storage tanks in the heat dissipation state up to the set heat amount or more; When the cooling unit stops, a cold energy compensation process is performed to supply cold energy from the heat storage tank in the standby state to the air conditioner. Air conditioning system. [Explanation of symbols]

[0059] W1...make-up water, W2...water, 1...air conditioning system, 2...air conditioner, 3...cooling section, 4...cooling tower, 4A...make-up water pipe, 10...heat storage system, 11...heat storage tank, 11A...first heat storage tank, 11B...second heat storage tank, 12...refrigeration machine, 13...heat exchanger, 14...first water supply pipe, 14A...first gate valve, 15...second water supply pipe, 15A...second gate valve, 20...control device, 21...control unit, 22...memory unit, 100, 200...timetable.

Claims

1. Equipped with multiple heat storage tanks for storing cold heat, Each heat storage tank transitions between a standby state in which cold energy is stored to a set amount or more and a heat dissipation state in which the stored cold energy is less than the set amount, When at least one of the heat storage tanks is in the standby state, a heat storage process is performed to store cold heat in the other heat storage tanks in the heat dissipation state up to the set heat amount or more; When a cooling unit that supplies cold heat to an air conditioner stops, a cold heat compensation process is performed to supply cold heat to the air conditioner from the heat storage tank in the standby state. Heat storage system.

2. When at least one heat storage tank is in the standby state, a heat dissipation process is performed to supply cold heat from the other heat storage tank to the air conditioner until the other heat storage tank is in the heat dissipation state, and then the heat storage process is performed to store cold heat in the other heat storage tank. The thermal storage system according to claim 1 .

3. The heat storage process is performed during a time period when the demand for commercial power is less than that during the time period when the heat dissipation process is performed. The thermal storage system according to claim 2 .

4. Each heat storage tank contains water as a heat medium. When at least one of the heat storage tanks is in the standby state, if the supply of makeup water to a cooling tower that dissipates heat from the cooling unit to the outside is cut off, a makeup water replenishment process is performed to supply the water from another heat storage tank to the cooling tower. A heat storage system according to any one of claims 1 to 3.

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