Thermal storage system and thermal storage method

Abstract

To provide a thermal storage system and a thermal storage method capable of suppressing decrease in the amount of stored heat during thermal storage operation conducted after being left for a long time following the end of heat release operation.SOLUTION: A thermal storage system according to the present embodiment is a thermal storage system in which, during thermal storage operation, a high-temperature heat medium is circulated to store heat in a solid sensible heat storage material and, during heat release operation, the heat medium at a low temperature is circulated in the direction opposite to that in the thermal storage operation to release heat from the solid sensible heat storage material. The system comprises a thermal storage tank group and a first valve. In the thermal storage tank group, multiple divided thermal storage tanks each containing the solid sensible heat storage material are connected in series in the flow direction of the heat medium. The divided thermal storage tanks include a first thermal storage tank, and a second thermal storage tank adjacent to the first thermal storage tank. The first valve opens and closes a flow path between the first and second thermal storage tanks. The first valve is closed since the end of the heat release operation until the start of the thermal storage operation.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE An embodiment of the present invention relates to a heat storage system and a heat storage method. [Background technology]

[0002] In recent years, power generation from natural energy sources such as solar power generation and wind power generation has been increasing, and there are regions where the amount of power generation is greater than the power demand depending on the season and time of day. In addition, there are times when the power demand is high depending on the season and time of day, and the amount of power generation is less than the power demand, resulting in a power shortage. In view of this, there is a conventional technology (see Patent Document 1) that uses heat storage to adjust power, which will be described with reference to Figs. 7 to 10.

[0003] FIG. 7 is a diagram showing a configuration example of a power adjustment system 1 including a conventional technology. The heat storage system 100 includes a heat storage tank group 380, an electric heater 39, a first fan 40, a second fan 41, valves 49 to 52, and a boiler 48 to which heat is supplied. Although the heat storage tank group 380 is called a group for convenience, it does not need to be composed of a plurality of heat storage tanks, and may be composed of one heat storage tank. When there is a surplus of power, the pump 45, the steam turbine 47, the generator 47a, and the second fan 41 are stopped. Then, the valves 49 and 50 are opened and the valves 51 and 52 are closed, and the electric heater 39 and the first fan 40 are operated using the surplus power. At this time, the first fan 40 circulates air 5 between the electric heater 39 and the heat storage tank group 380. Air 5 is heated by heat generated by electric heater 39, and the heat is transported to heat storage tank group 380, where it heats the heat storage material in heat storage tank group 380. The heat storage material is solid sensible heat storage material 23, such as rock. This causes heat to be stored in the heat storage material. The solid arrow indicates air flow direction 32 during heat storage operation, and the dotted arrow indicates air flow direction 33 during heat dissipation operation.

[0004] When there is no surplus power, the electric heater 39 and the first blower 40 are stopped, the valves 49 and 50 are closed, the valves 51 and 52 are opened, and the pump 45 and the second blower 41 are operated. The second blower 41 circulates the air 5 between the heat storage tank group 380 and the boiler 48. The air 5 is heated by the heat storage material in the heat storage tank group 380, and transports the heat to the boiler 48. In the boiler 48, the water 43 brought in by the pump 45 is heated by the heat from the air 5 to produce steam 44, and the air 5 is cooled and discharged. In this way, the heat dissipation operation is performed. The steam 44 flows through the steam turbine 47 at a low temperature and low pressure, thereby rotating the steam turbine 47, which is an impeller, and the generator 47a mechanically connected to the steam turbine 47 generates electricity. The steam discharged from the steam turbine 47 is cooled by cooling water, for example seawater, in the condenser 46 to become water 43, which is then circulated. As a result, steam 44 is generated using the heat stored in the heat storage material in the heat storage tank group 380, and electricity is generated. In this way, power adjustment is performed by using electricity when there is a power surplus and generating electricity when there is no power surplus.

[0005] FIG. 8 is a diagram showing the state inside the heat storage tank group 380 of the heat storage system 100 according to the conventional technology. FIG. 8(a) shows the flow direction of the air 5 in the heat storage tank group 380, and FIG. 8(b) shows the temperature distribution in the heat storage tank group 380. During the heat storage operation, a thermocline 26 showing a steep temperature gradient in the flow direction is formed inside the heat storage tank group 380, which moves from the upstream side to the downstream side, and the heat storage operation ends when the temperature of the air 5 flowing out of the heat storage tank group 380 rises to, for example, the heat resistance temperature of the first blower 40 or the valve 50. FIG. 8(b) shows the temperature distribution of the solid sensible heat storage material 23 in the heat storage tank group 380 at the end of the first heat storage operation. The lines drawn in FIG. 8(b) represent the temperature. The first heat storage temperature 14 is an example during the heat storage operation. The heat storage temperature rises 28 to the second heat storage temperature 15, and the thermocline 26 reaches the outlet during heat storage operation. The graph lines for the first heat storage temperature 14 and the second heat storage temperature 15 each include the thermocline 26. When the heat storage tank outlet temperature reaches the heat storage operation end temperature 27 (the state in which the thermocline 26 shown by the dashed dotted line has reached the heat storage operation end temperature 27), the heat storage operation ends.

[0006] FIG. 9 is a diagram showing the state inside the heat storage tank group 380 during heat dissipation operation of the heat storage system 100 according to the conventional technology. FIG. 9(a) shows the flow direction of the air 5 in the heat storage tank group 380, and FIG. 9(b) shows the temperature distribution in the heat storage tank group 380. During heat dissipation operation, the air 5 is circulated in the opposite direction to that during heat storage operation. The thermocline 26 of the heat storage tank group 380 at that time moves from the upstream side to the downstream side during heat dissipation operation, and the temperature distribution at that time is shown in FIG. 9(b). The end of the heat dissipation operation is determined by the operation time of the heat utilization load side, and the third heat storage temperature 31 is the temperature distribution at the end of the heat dissipation operation. Note that the graph line of the third heat storage temperature 31 includes the thermocline 26. In this way, a sufficiently large amount of the stored heat often remains at the end of the heat dissipation operation. During the long period between the end of the heat dissipation operation and the start of the heat storage operation, the heat storage tank group 380 is left alone, but the temperature distribution changes during that time, and at the start of the heat storage operation, the temperature becomes like the fourth heat storage temperature 18. The temperature drops in the relatively high temperature area and rises in the relatively low temperature area, and the temperature is averaged out.

[0007] FIG. 10 is a diagram showing the state inside the heat storage tank group 380 during heat storage operation of the heat storage system 100 according to the conventional technology. FIG. 10(a) shows the flow direction of the air 5 in the heat storage tank group 380, and FIG. 10(b) shows the temperature distribution in the heat storage tank group 380. When the heat storage operation is started from the state of the fourth heat storage temperature 18, the heat storage temperature is increased 28 from the fourth heat storage temperature 18 to the fifth heat storage temperature 19. The graph line of the fifth heat storage temperature 19 includes the thermocline 26. Even if the air 5 moving downstream of the thermocline 26 exists in an area where the heat storage temperature is nearly flat, the air 5 heats the solid sensible heat storage material 23 because the temperature on the downstream side is lower, so the heat storage temperature rises. When the heat storage tank outlet temperature during the heat storage operation reaches the heat storage operation end temperature 27 (the state of the temperature distribution shown by the dashed line), the heat storage operation is ended, but the heat storage operation end temperature 27 is reached earlier than in the case of FIG. 8. Comparing the temperature profile of the second heat storage temperature 25 in FIG. 8 with the temperature profile of the fifth heat storage temperature 19 in FIG. 10, the latter has more low temperature regions and the amount of heat stored in the heat storage tank group 380 is smaller.

[0008] In the conventional technology, the heat radiated from the heat storage system 100 is used as a heat source for the steam turbine 47, but it may also be used for air conditioning or other purposes. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent Publication No. 2021-1597 Summary of the Invention [Problem to be solved by the invention]

[0010] When the heat dissipation operation is left for a long time, the heat storage temperature distribution becomes averaged, and the outlet temperature during the subsequent heat storage operation becomes higher. The increase in outlet temperature brings the end time of the heat storage operation forward, resulting in a problem of a smaller amount of stored heat.

[0011] An object of the present invention is to provide a heat storage system and a heat storage method capable of suppressing a decrease in the amount of stored heat during a heat storage operation carried out after the system has been left unused for a long period of time following the end of a heat dissipation operation. [Means for solving the problem]

[0012] The heat storage system according to the present embodiment is a heat storage system that circulates a high-temperature heat medium during heat storage operation to store heat in a solid sensible heat storage material, and circulates the low-temperature heat medium in the opposite direction to that during heat storage operation to dissipate heat from the solid sensible heat storage material during heat dissipation operation, and includes a heat storage tank group and a first valve. The heat storage tank group is a heat storage tank group in which a plurality of split heat storage tanks containing solid sensible heat storage materials are connected in series in the flow direction of the heat medium, and includes a first heat storage tank and a second heat storage tank adjacent to the first heat storage tank as split heat storage tanks. The first valve opens and closes a flow path between the first heat storage tank and the second heat storage tank. The first valve is closed from the end of the heat dissipation operation to the start of the heat storage operation. Effect of the Invention

[0013] According to this embodiment, it is possible to suppress a decrease in the amount of stored heat during the heat storage operation that is performed after the heat dissipation operation is completed and the device is left unused for a long period of time. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a diagram showing an example of the configuration of a heat storage tank according to the first embodiment. [Diagram 2] 6 is a diagram showing an example of the air flow direction during a heat dissipation operation of the heat storage tank and a temperature distribution of the heat storage tank after the heat dissipation operation. [Diagram 3] 4 is a diagram showing an example of air flow direction and temperature distribution during heat storage operation of the heat storage tank. FIG. [Figure 4] FIG. 4 is a diagram showing an example in which a heat storage tank group is divided into three in the first embodiment. [Diagram 5] FIG. 11 is a diagram showing an example of the configuration of a heat storage tank according to a second embodiment. [Figure 6] FIG. 11 is a diagram showing an example in which a heat storage tank group is divided into three in the second embodiment. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a power conditioning system including a thermal storage system according to a conventional technology. [Figure 8] FIG. 13 is a diagram showing the state inside the heat storage tank during heat storage operation according to the prior art. [Figure 9] 1A and 1B are diagrams showing the state inside the heat storage tank during heat dissipation operation and after being left unused for a long period of time according to the conventional technology. [Figure 10] FIG. 13 is a diagram showing the state inside the heat storage tank during heat storage operation after being left unused for a long period of time according to the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments.

[0016] (First embodiment) A first embodiment corresponding to claims 1, 2, and 5 will be described with reference to Figs. 1 to 4 and 7. As shown in Figs. 1 and 7, a heat storage system 100 according to this embodiment includes an electric heater 39, a first fan 40, a second fan 41, valves 49 to 52, and a boiler 48 to which heat is supplied, and replaces the heat storage tank group 380 in Fig. 7 with a heat storage tank group 38. The heat storage tank group 38 according to this embodiment is a heat storage tank group composed of a plurality of heat storage tanks 29 and 30. Note that the same numbers may be used to denote parts that are the same as those in the prior art, and the description may be omitted.

[0017] FIG. 1 is a diagram showing a configuration example of a heat storage tank group 38 according to the first embodiment. As shown in FIG. 1, the heat storage tank group 38 according to the first embodiment is a heat storage tank group in which a plurality of split heat storage tanks each containing a solid sensible heat storage material 23 are connected in series in the flow direction of the heat medium, and includes a first heat storage tank 29 as a split heat storage tank, a second heat storage tank 30 adjacent to the first heat storage tank 29, and a first valve 16. That is, the heat storage tanks 29 and 30 are divided into two tanks, the first heat storage tank 29 on the upstream side and the second heat storage tank 30 on the downstream side, in series in the air flow direction during heat storage operation. The first valve 16 is provided in the flow path between the first heat storage tank 29 and the second heat storage tank 30. The heat storage material of the first heat storage tank 29 and the second heat storage tank 30 is the solid sensible heat storage material 23, for example, rock. 2, an example in which the tank is divided into the first heat storage tank 29 and the second heat storage tank 30 will be described, but the invention is not limited to this. For example, the number of divisions may be any number equal to or greater than two.

[0018] 7, pipes L2 and L3 are joined between joints n1 and n2. Furthermore, pipe L4 is joined between joint n1 and the first heat storage tank 29. Furthermore, pipe L5 is joined between joint n1 and the second heat storage tank 30.

[0019] The heat dissipation operation and the subsequent long-term standing will be described. When there is no surplus power, as described above, the electric heater 39 and the first blower 40 are stopped, the valves 49 and 50 are closed, the valves 51 and 52 are opened, and the pump 45 and the second blower 41 are operated. The second blower 41 circulates the air 5 between the heat storage tank group 38 and the boiler 48 through the pipes L2, L5, and L4. The air 5 is heated by the heat storage material of the heat storage tank group 38, and the heat is transported to the boiler 48 through the pipes L2 and L5. In the boiler 48, the water 43 brought in by the pump 45 is heated by the heat from the air 5 to produce steam 44, and the air 5 is cooled and flows out. In this way, the heat dissipation operation is performed. In this embodiment, the heat medium is air 5, but it may be a gas other than air or a liquid.

[0020] FIG. 2 is a diagram showing the flow direction of air 5 during the heat dissipation operation of the heat storage tank group 38 according to the first embodiment, and an example of the temperature distribution of the heat storage tank group 38 after the heat dissipation operation. As shown in FIG. 2(a), air 5 is circulated through the second heat storage tank 30 and the first heat storage tank 29 in that order to dissipate heat. The heat dissipation operation ends due to the operation time of the heat utilization load side (boiler 48 in FIG. 7), and the first valve 16 in the flow path between the first heat storage tank 29 and the second heat storage tank 30 is closed. As shown in FIG. 2(b), the temperature distribution at the end of the heat dissipation operation becomes the third heat storage temperature 31. When left for a long time, the third heat storage temperature 31, which is the temperature distribution at the end of the heat dissipation operation, is averaged in the first heat storage tank 29 like the sixth heat storage temperature 20. On the other hand, in the second heat storage tank 30, the first valve 16 is closed and the temperature was originally constant, so there is no region where the temperature rises, and a low temperature is maintained like the seventh heat storage temperature 21.

[0021] The heat storage operation performed after a long period of time following the heat dissipation operation will be described. As described above, the valves 49 and 50 are opened, and the valves 51 and 52 are closed to operate the electric heater 39 and the first blower 40. At this time, the first blower 40 circulates the air 5 between the electric heater 39 and the heat storage tank group 38 through the pipes L3, L4, and L5. The air 5 is heated by the heat generated by the electric heater 39, and the heat is transported to the heat storage tank group 38 to heat the heat storage material in the heat storage tank group 38. This causes the heat storage material to store heat. In this way, the heat storage system 100 according to this embodiment circulates the air 5, which is a high-temperature heat medium, during the heat storage operation to store heat in the solid sensible heat storage material 23 of the heat storage tank group 38, and circulates the air 5, which is a low-temperature heat medium, during the heat dissipation operation to dissipate heat from the solid sensible heat storage material 23 of the heat storage tank group 38.

[0022] FIG. 3 is a diagram showing an example of the flow direction and temperature distribution of the air 5 in the heat storage operation performed after a long period of time left unattended after the heat dissipation operation in the heat storage tank group 38 according to the first embodiment. As shown in FIG. 3(a), after a long period of time left unattended, the first valve 16 is opened to perform the heat storage operation. As shown in FIG. 3(b), the heat storage temperature increase 28 is performed, and the heat storage temperature distribution at the end of the heat storage operation becomes the eighth heat storage temperature 22. The graph line of the eighth heat storage temperature 22 includes the thermocline 26. In the first heat storage tank 29 and upstream of the thermocline 26 in the second heat storage tank 30, the heat storage temperature becomes constant at a temperature that matches the temperature of the air 5. The thermocline 26 reaches the outlet during the heat storage operation. The heat storage operation ends when the heat storage tank outlet temperature reaches the heat storage operation end temperature 27, so the same as FIG. 8 occurs, and the end of the heat storage operation is not accelerated. Comparing the second heat storage temperature 15 in Fig. 8 with the fifth heat storage temperature 19 in Fig. 10, the temperature profile of the eighth heat storage temperature 22 in Fig. 3 is the same as the second heat storage temperature 25 in Fig. 8, but different from the fifth heat storage temperature 19 in Fig. 10. The amount of heat stored in the heat storage tank group 38 in Fig. 3 is the same as the amount of heat stored in Fig. 8, and is not reduced like the amount of heat stored in Fig. 10. Therefore, in the first embodiment, the amount of heat stored does not decrease during heat storage operation after being left unused for a long period of time.

[0023] In this way, by leaving the first valve 16 closed for a long time, the transfer of heat from the first heat storage tank 29 to the second heat storage tank 30 is suppressed, and the second heat storage tank 30 is maintained at a low temperature. As a result, the time at which the heat storage tank outlet temperature reaches the heat storage operation end temperature 27 during the heat storage operation can be delayed, and the decrease in the heat storage amount of the heat storage tank group 38 is suppressed. That is, the heat storage amount in the heat storage tank group 38 does not decrease during the heat storage operation after being left for a long time. This has the effect of preventing the decrease in the heat storage amount during the heat storage operation performed after being left for a long time after the end of the heat dissipation operation, which was a problem in the conventional technology. The heat dissipated from the heat storage system 100 may be used as a heat source for the steam turbine 47, or may be used for purposes such as air conditioning.

[0024] 4 is a diagram showing an example in which the heat storage tank group 38 is divided into three. As mentioned above, the number of divisions may be any number of divisions of two or more. However, if the tank is divided into three tanks, the third heat storage tank 35, the fourth heat storage tank 36, and the fifth heat storage tank 37, in order from the upstream during the heat storage operation, the first valves 16a and 16b may be installed between the third heat storage tank 35 and the fourth heat storage tank 36, between the fourth heat storage tank 36 and the fifth heat storage tank 37, or in both tanks. In the case where the first valve 16a is installed between the third heat storage tank 35 and the fourth heat storage tank 36, when a thermocline 26 exists in the third heat storage tank 35 at the end of the heat dissipation operation, the first valve 16a is closed during the long period of time thereafter. In the case where the first valve 16b is installed between the fourth heat storage tank 36 and the fifth heat storage tank 37, when the thermocline 26 exists in the fourth heat storage tank 36 at the end of the heat dissipation operation, the first valve 16b is closed during the long period of time thereafter. This provides the same effect as the case where the number of divisions is two.

[0025] When the heat storage tank group 38 is divided into three or more as shown in FIG. 4, it is preferable that the second heat storage tank 30 is a divided heat storage tank located at the most downstream position during heat storage operation. If the second heat storage tank 30 is a divided heat storage tank located downstream (heat storage operation) of the divided heat storage tank in which the thermocline 26 exists at the end of the heat dissipation operation, there is an effect of closing the first valve 16, but the position of the thermocline 26 at the end of the heat dissipation operation differs depending on the operation of the heat utilization destination, and if the second heat storage tank 30 is located upstream of the thermocline 26 (heat storage operation), there is no effect. Therefore, in order to reliably maintain the second heat storage tank 30 at a low temperature and obtain the effect, it is preferable that the second heat storage tank 30 is a divided heat storage tank located at the most downstream position during the heat storage operation, and the first heat storage tank 29 is a heat storage tank adjacent to the upstream of the second heat storage tank 30.

[0026] As described above, according to this embodiment, during the heat dissipation operation, the air 5 is circulated through the second heat storage tank 30 and the first heat storage tank 29 in that order, and when the system is left for a long time after the heat dissipation operation is completed, the first valve 16 in the flow path between the first heat storage tank 29 and the second heat storage tank 30 is closed. This prevents the heat of the first heat storage tank 29 from moving to the second heat storage tank 30 during the long time of leaving, and the temperature of the second heat storage tank 30 can be maintained at a low temperature. As a result, when the first valve 16 is opened and the air 5 is circulated through the first heat storage tank 29 and the second heat storage tank 30 in that order after the system is left for a long time, the temperature profile when the heat storage tank outlet temperature reaches the heat storage operation end temperature 27 becomes equivalent to the initial heat storage operation shown in FIG. 8, and the shortening of the heat storage operation time is suppressed, and the decrease in the amount of heat stored in the heat storage tank group 38 during the heat storage operation performed after the system is left for a long time after the heat dissipation operation is completed is suppressed.

[0027] Second embodiment A second embodiment corresponding to claims 3, 4, and 6 will be described with reference to Figs. 5 and 6. The heat storage system 100 according to the second embodiment differs from the heat storage system 100 according to the first embodiment in that a second valve 17 is provided on the inlet side piping of the second heat storage tank 30. The differences from the heat storage system 100 according to the first embodiment will be described below.

[0028] Fig. 5 is a diagram showing an example of the configuration of a heat storage tank group 38 according to the second embodiment. As shown in Fig. 5, a second valve 17 is further provided on the inlet side pipe L5 of the second heat storage tank 30 during the heat dissipation operation.

[0029] At the end of the heat dissipation operation, the upstream pipe L5 of the second heat storage tank 30 in the heat dissipation operation is at approximately the same temperature as the solid sensible heat storage material 23 near the inlet and outlet of the heat storage tank. However, if the tank is left for a long time after the end of the heat dissipation operation, heat leaks to the outside (for example, the atmosphere) which has a lower temperature, and the temperature of the inlet side pipe L5 of the second heat storage tank 30 drops. Therefore, the temperature of the solid sensible heat storage material 23 near the inlet of the heat storage tank during the heat dissipation operation in the second heat storage tank 30 may drop due to heat leak to the pipe L5. In the first embodiment, the heat transfer from the first heat storage tank 29 suppresses the increase in the heat storage temperature of the solid sensible heat storage material 23 in the second heat storage tank 30. However, in the second embodiment, if the stored heat leaks from the second heat storage tank 30, it becomes necessary to supply more heat to the heat storage tank group 38 in the next heat storage operation, so it is desirable to reduce the heat leak.

[0030] For this reason, after the heat dissipation operation is completed, not only the first valve 16 but also the second valve 17 is closed. Closing the second valve 17 suppresses heat leakage from the second heat storage tank 30 to the inlet side pipe L5 when the system is left unused for a long period of time after the heat dissipation operation, and suppresses an increase in the total amount of heating in the next heat storage operation.

[0031] Closing the first valve 16 further suppresses the decrease in the amount of heat stored in the heat storage tank group 38 during heat storage operation after being left unused for a long time after the heat dissipation operation, and closing the second valve 17 suppresses an increase in the total amount of heating in the next heat storage operation. The heat dissipated from the heat storage system 100 according to the second embodiment may be used as a heat source for the steam turbine 47, or may be used for purposes such as air conditioning.

[0032] 6 is a diagram showing an example in which the heat storage tank group 38 is divided into three. As mentioned above, the number of divisions may be any number equal to or greater than two. However, if the tank is divided into three tanks, the third heat storage tank 35, the fourth heat storage tank 36, and the fifth heat storage tank 37, in that order from the upstream during heat storage operation, the second valve 17 is installed between the fifth heat storage tank 37, which is the most downstream tank, and the pipe L5. Heat leakage from the fifth heat storage tank 37, which is the divided heat storage tank adjacent to the pipe L5, to the pipe L5 is suppressed. This provides the same effect as the case in which the number of divisions is two.

[0033] As described above, according to this embodiment, during heat dissipation operation, air 5 is circulated through the second heat storage tank 30 and then through the first heat storage tank 29, and when the system is left for a long time after the end of the heat dissipation operation, not only the first valve 16 in the circulation path between the first heat storage tank 29 and the second heat storage tank 30 but also the second valve 17 provided on the inlet side pipe L5 during the heat dissipation operation of the second heat storage tank 30 is closed. This suppresses heat leakage from the second heat storage tank 30 to the inlet side pipe L5 when the system is left for a long time, and suppresses a decrease in the amount of heat storage, thereby suppressing an increase in the total amount of heating in the next heat storage operation. [Explanation of symbols]

[0034] 1: power conditioning system including heat storage system, 5: air, 16, 16a, 16b: first valve, 17: second valve, 29: first heat storage tank, 30: second heat storage tank group, 38: heat storage tank group, 39: electric heater, 40: first blower, 41: second blower, 42: air, 43: water, 44: steam, 45: pump, 46: condenser, 47: steam turbine, 47a: generator, 48: boiler, 49-52: valve, 100: heat storage system, 500; control device, 502: thermometer.

Claims

1. A heat storage system in which a high-temperature heat medium is circulated during a heat storage operation to store heat in a solid sensible heat storage material, and a low-temperature heat medium is circulated in a direction opposite to that during the heat storage operation to release heat from the solid sensible heat storage material, a heat storage tank group in which a plurality of split heat storage tanks each containing the solid sensible heat storage material are connected in series in a flow direction of the heat medium, the split heat storage tanks including at least a first heat storage tank and a second heat storage tank adjacent to the first heat storage tank; a first valve that opens and closes a flow path between the first heat storage tank and the second heat storage tank; Equipped with The first valve is closed from the time when the heat dissipation operation is completed to the time when the heat storage operation is started.

2. The heat storage system according to claim 1 , wherein the second heat storage tank is a heat storage tank located most downstream during the heat storage operation, and the first heat storage tank is a heat storage tank adjacent to and upstream of the second heat storage tank.

3. The first heat storage tank is a heat storage tank adjacent to the second heat storage tank upstream during the heat storage operation, and a second valve that opens and closes a flow path on an outlet side of the second heat storage tank during the heat storage operation, Further preparation The heat storage system according to claim 1 or 2, wherein the second valve is closed from the end of the heat dissipation operation to the start of the heat storage operation.

4. a second valve configured to open and close a flow path on an outlet side of the divided heat storage tank located at the most downstream side during the heat storage operation, Further preparation The heat storage system according to claim 1 or 2, wherein the second valve is closed from the end of the heat dissipation operation to the start of the heat storage operation.

5. A heat storage system in which a high-temperature heat medium is circulated during a heat storage operation to store heat in a solid sensible heat storage material, and a low-temperature heat medium is circulated in a direction opposite to that during the heat storage operation to release heat from the solid sensible heat storage material, a heat storage tank group in which a plurality of split heat storage tanks each containing the solid sensible heat storage material are connected in series in a flow direction of the heat medium, the split heat storage tanks including at least a first heat storage tank and a second heat storage tank adjacent to the first heat storage tank; a first valve that opens and closes a flow path between the first heat storage tank and the second heat storage tank; Equipped with The heat storage method includes closing the first valve from the end of the heat dissipation operation to the start of the heat storage operation.

6. The heat storage method according to claim 5, further comprising a second valve that opens and closes a flow path on an outlet side of the second heat storage tank during the heat storage operation, and the second valve is closed from the end of the heat dissipation operation to the start of the heat storage operation.

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