Thermal storage system

Abstract

The present invention provides a heat storage system capable of suitably carrying out heat storage and heat release using a divided heat storage tank. For example, it provides a heat storage system with low air pressure loss during heat storage operation and heat release operation. [Solution] According to one embodiment, the heat storage system comprises a first to the Nth heat storage tank (N is an integer of 2 or more) connected in series with respect to each other. The system further comprises a fluid flow path for supplying a heat transfer fluid to the first to the Nth heat storage tanks, which includes a bypass flow path for circulating the heat transfer fluid so as to bypass one or more of the first to Nth heat storage tanks. The system further comprises one or more valves provided in the fluid flow path. The one or more valves are configured to be switchable with respect to any Kth heat storage tank (K is any integer from 1 to N) among the first to Nth heat storage tanks, either supplying the heat transfer fluid to the K heat storage tank or circulating the heat transfer fluid so as to bypass the K heat storage tank.

Description

Technical Field

[0001] Embodiments of the present invention relate to a heat storage system.

Background Art

[0002] In recent years, power generation using natural energy such as solar power generation and wind power generation has been increasing. Depending on the season and time zone, there are areas where the power generation amount becomes larger than the power demand. On the other hand, depending on the season and time zone, when the power demand increases, the power generation amount may become smaller than the power demand, resulting in a power shortage. Therefore, the following first conventional technology for performing power adjustment using heat storage may be used.

[0003] FIG. 14 is a schematic diagram showing the configuration of a heat storage system of the first conventional technology.

[0004] The heat storage system of FIG. 14 includes a heat storage tank 1, an electric heater 2, a blower 3, a blower 4, an air flow path 5, a water flow path 6, a steam flow path 7, a condensate pump 8, a boiler 9, a steam turbine 10, a condenser 11, a valve 12, a valve 13, a valve 14, and a valve 15. FIG. 14 further shows air 101, water 102, and steam 103 circulating in the heat storage system of FIG. 14. This air 101 is a heat transfer fluid.

[0005] <图14の蓄熱システムは、蓄熱槽1と、電気ヒータ2と、送風機3と、送風機4と、空気流路5と、水流路6と、蒸気流路7と、復水ポンプ8と、ボイラ9と、蒸気タービン10と、復水器11と、弁12と、弁13と、弁14と、弁15とを具備する。図14は更に、図14の蓄熱システム内を循環する空気101、水102、及び蒸気103を示している。この空気101は、熱搬送流体である。 When the power is surplus, the heat storage system of FIG. 14 stops the blower 4, the condensate pump 8, and the steam turbine 10, opens the valves 12 and 13, closes the valves 14 and 15, and operates the electric heater 2 and the blower 3 using the surplus power. The blower 3 circulates the air 101 between the heat storage tank 1 and the electric heater 2 through the air flow path 5. The air 101 is heated by the heat generated by the electric heater 2, transports the heat to the heat storage tank 1, and heats the heat storage material in the heat storage tank 1. The heat storage material is a solid sensible heat storage material, for example, rock. The heat transported by the air 101 is stored by the heat storage material. In this way, the heat storage operation is performed. <00>

[0006] On the other hand, if there is no surplus electricity, the heat storage system in Figure 14 stops the electric heater 2 and blower 3, closes valves 12 and 13, opens valves 14 and 15, and operates blower 4 and condensate pump 8. Blower 4 circulates air 101 between the heat storage tank 1 and boiler 9 via the air passage 5. The air 101 is heated by the heat storage material in the heat storage tank 1 and the heat is transported to boiler 9. Boiler 9 heats the water 102, which is brought in by condensate pump 8 via the water passage 6, with the heat from the air 101. As a result, steam 103 is produced from the water 102 in boiler 9, and the air 101 cools down and flows out of boiler 9. In this way, heat dissipation operation is performed.

[0007] During heat dissipation operation, steam 103 flows into the steam turbine 10 via the steam channel 7. As the steam 103 circulates within the steam turbine 10 at low temperature and low pressure, it rotates the steam turbine 10, which is the impeller. As a result, a generator (not shown) mechanically connected to the steam turbine 10 generates electricity. The steam 103 discharged from the steam turbine 10 flows into the condenser 11 via the steam channel 7. The condenser 11 cools the steam 103 with cooling water (e.g., seawater). As a result, the steam 103 is converted into water 102 within the condenser 11, and the water 102 is discharged into the water channel 6. The water 102 and steam 103 circulate via the water channel 6 and the steam channel 7. In this way, the heat stored in the heat storage material in the heat storage tank 1 generates steam 103, and is converted into electrical energy through power generation using the steam 103.

[0008] The energy storage system in Figure 14 stores heat using surplus electricity when there is a surplus, and generates electricity using the stored heat when there is no surplus electricity. In this way, power adjustment is performed.

[0009] Figure 15 is a schematic diagram showing the configuration of the second prior art heat storage system. In the explanation of the second prior art, explanations of parts that are the same as the first prior art will be omitted as appropriate.

[0010] The thermal energy storage system in Figure 15 comprises a thermal energy storage tank 1, an electric heater 2, a blower 3, a blower 4, an air passage 5, a water passage 6 (not shown), a steam passage 7, a condensate pump 8 (not shown), a boiler 9 (not shown), a steam turbine 10 (not shown), a condenser 11 (not shown), valves 12, 14, 16, 17, 18, a three-way valve 19, a three-way valve 20, and a three-way valve 21. Figure 15 further shows the air 101 and steam 103 circulating within the thermal energy storage system of Figure 15, while the illustration of the water 102 circulating within the thermal energy storage system of Figure 15 is omitted.

[0011] The thermal storage tank 1 in Figure 15 is divided into three separate thermal storage tanks 1a to 1c. The air passage 5 in Figure 15 also includes a bypass passage for circulating air 101 by bypassing one of the separate thermal storage tanks 1a to 1c. Valves 17 and 18 are provided in the bypass passage. The lines drawn within the separate thermal storage tanks 1a to 1c schematically represent the temperature distribution within the separate thermal storage tanks 1a to 1c. For example, the horizontal line drawn within the separate thermal storage tank 1b indicates that the temperature within the separate thermal storage tank 1b is relatively low and constant between the upstream and downstream sides of the air 101. The broken lines drawn within the separate thermal storage tanks 1a and 1c indicate that there are high-temperature and low-temperature areas within the separate thermal storage tanks 1a and 1c.

[0012] In the thermal storage system shown in Figure 15, the divided thermal storage tanks 1a to 1c from which heat is released can be freely selected during heat release operation. For example, if heat is to be released only from divided thermal storage tank 1a, valves 14 and 17 are opened, valves 12, 16, and 18 are closed, the three-way valve 19 is opened between divided thermal storage tank 1a and the bypass flow path, the three-way valve 20 is closed, the three-way valve 21 is opened between thermal storage tank 1 and blower 4, the electric heater 2 and blower 3 are stopped, and blower 4 and condensate pump 8 are started. On the other hand, if heat is to be released only from the divided heat storage tank 1b, valves 17 and 18 are opened, valves 12, 14 and 16 are closed, the three-way valve 19 is opened between the divided heat storage tank 1b and the bypass flow path, the three-way valve 20 is opened between the divided heat storage tank 1b and the bypass flow path, the three-way valve 21 is opened between the heat storage tank 1 and the blower 4, the electric heater 2 and blower 3 are stopped, and the blower 4 and condensate pump 8 are operated. However, in this case, the air 101 can flow not only through the divided heat storage tank 1b but also through the bypass flow path which runs parallel to the divided heat storage tank 1b, so most of the air 101 flows through the bypass flow path and heat is not released properly from the divided heat storage tank 1b. This is because the airflow resistance of the air 101 is large in the divided heat storage tank 1b and small in the bypass flow path.

[0013] Furthermore, in the thermal storage system shown in Figure 15, even when heat is released only from the two divided thermal storage tanks 1a and 1b, or only from the two divided thermal storage tanks 1b and 1c, heat is not released properly from the divided thermal storage tank 1b. Also, in the thermal storage system shown in Figure 15, it is not possible to store heat only in the divided thermal storage tank 1b, or only in the divided thermal storage tank 1c, or only in the two divided thermal storage tanks 1b and 1c during thermal storage operation. This is because the thermal storage system shown in Figure 15 is configured so that the air 101 heated by the electric heater 2 always flows through the divided thermal storage tank 1a. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] International Patent Application Publication WO2017 / 055525 [Overview of the project] [Problems that the invention aims to solve]

[0015] When the heat storage tank 1 is divided into divided heat storage tanks 1a to 1c, it becomes difficult to adequately store heat in each of the divided heat storage tanks 1a to 1c, and to adequately dissipate heat from each of the divided heat storage tanks 1a to 1c. Furthermore, the heat storage tank 1, which is filled with a solid sensible heat storage material, has the problem of high pressure loss in the air 101 circulating inside the heat storage tank 1. High pressure loss in the air 101 circulating inside the heat storage tank 1 increases the load on the blowers 3 and 4, resulting in increased power consumption for the blowers 3 and 4.

[0016] Therefore, the object of the embodiments of the present invention is to provide a heat storage system capable of suitably carrying out heat storage and heat release using a divided heat storage tank. For example, the object is to provide a heat storage system with low air pressure loss during heat storage operation and heat release operation. [Means for solving the problem]

[0017] According to one embodiment, the heat storage system comprises first to nth heat storage tanks (N being an integer of 2 or more) connected in series with respect to each other. The system further comprises a fluid flow path for supplying a heat transfer fluid to the first to nth heat storage tanks, the fluid flow path including a bypass flow path that causes the heat transfer fluid to flow so as to bypass one or more of the first to nth heat storage tanks. The system further comprises one or more valves provided in the fluid flow path. The one or more valves are configured to be switchable with respect to any kth heat storage tank (K being any integer from 1 to N) among the first to nth heat storage tanks, either supplying the heat transfer fluid to the k heat storage tank or causing the heat transfer fluid to flow so as to bypass the k heat storage tank. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram showing the configuration of the heat storage system of the first embodiment. [Figure 2] This is a schematic diagram (1 / 2) showing the operation of the heat storage system of the first embodiment during heat storage operation. [Figure 3]It is a schematic diagram (2 / 2) showing the operation of the heat storage system of the first embodiment during heat storage operation. [Figure 4] It is a schematic diagram (1 / 2) showing the operation of the heat storage system of the first embodiment during heat dissipation operation. [Figure 5] It is a schematic diagram (2 / 2) showing the operation of the heat storage system of the first embodiment during heat dissipation operation. [Figure 6] It is a schematic diagram showing the configuration of a modified example of the heat storage system of the first embodiment. [Figure 7] It is a schematic diagram showing the operation of the heat storage system of the second embodiment during heat storage operation. [Figure 8] It is a schematic diagram showing the operation of the heat storage system of the second embodiment during heat dissipation operation. [Figure 9] It is a schematic diagram showing the configuration of the heat storage system of the third embodiment. [Figure 10] It is a schematic diagram showing the configuration of the heat storage system of the fourth embodiment. [Figure 11] It is a schematic diagram showing the configuration of the heat storage system of the fifth embodiment. [Figure 12] It is a schematic diagram (1 / 2) showing the operation of the heat storage system of the fifth embodiment during heat storage operation. [Figure 13] It is a schematic diagram (1 / 2) showing the operation of the heat storage system of the fifth embodiment during heat storage operation. [Figure 14] It is a schematic diagram showing the configuration of the heat storage system of the first prior art. [Figure 15] It is a schematic diagram showing the configuration of the heat storage system of the second prior art.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIGS. 1 to 15, the same components are denoted by the same reference numerals, and redundant descriptions are omitted.

[0020] (First Embodiment) Figure 1 is a schematic diagram showing the configuration of the heat storage system of the first embodiment. In describing the heat storage system of this embodiment, explanations of parts that are the same as those of the first or second prior art heat storage system will be omitted as appropriate.

[0021] The heat storage system of this embodiment comprises a heat storage tank 1, an electric heater 2, a blower 3, a blower 4, an air passage 5, a water passage 6, a steam passage 7, a condensate pump 8, a boiler 9, a steam turbine 10, a condenser 11, valves 12, 13, 14, 15, 22, three-way valves 23, 24, 25, and 26, and a control unit 31. Figure 1 further shows air 101, water 102, and steam 103 circulating within the heat storage system of this embodiment. Blower 3, blower 4, air passage 5, and air 101 are examples of a first fluid transport unit, a second fluid transport unit, a fluid passage, and a heat transport fluid, respectively. Valves 22 and three-way valves 23-26 are examples of one or more valves.

[0022] The heat storage tank 1 of this embodiment includes a divided heat storage tank 1a, a divided heat storage tank 1b, and a divided heat storage tank 1c. Divided heat storage tanks 1a to 1c are examples of the 1st to Nth heat storage tanks (N is an integer of 2 or more). Furthermore, each of the divided heat storage tanks 1a to 1c is an example of an arbitrary Kth heat storage tank (K is any integer from 1 to N). The air passage 5 of this embodiment includes a bypass passage 5a, a bypass passage 5b, and a bypass passage 5c.

[0023] The heat storage tank 1 of this embodiment is divided into two or more divided heat storage tanks in the direction of the air flow 101, and in Figure 1 it is divided into three divided heat storage tanks 1a to 1c. Although the heat storage tank 1 is divided into three in Figure 1, it may be divided into N other parts. The divided heat storage tanks 1a to 1c are connected in series with respect to the air flow 101. Each of the divided heat storage tanks 1a to 1c contains a heat storage material. The heat storage material of this embodiment is a solid sensible heat storage material, such as rock.

[0024] The air passage 5 includes a heat storage circuit section including a heat storage tank 1, an electric heater 2, and a blower 3, and a heat dissipation circuit section including a heat storage tank 1, a blower 4, and a boiler 9. In the heat storage circuit section, valve 13, electric heater 2, blower 3, and valve 12 are arranged in series. In the heat dissipation circuit section, valve 14, boiler 9, blower 4, and valve 15 are arranged in series. In the common section of these circuit sections, a three-way valve 23, divided heat storage tank 1a, three-way valve 24, divided heat storage tank 1b, three-way valve 25, divided heat storage tank 1c, and three-way valve 26 are arranged in series. On the other hand, in the circulation passage section including the water passage 6 and the steam passage 7, a condensate pump 8, a boiler 9, a steam turbine 10, and a condenser 11 are arranged in series.

[0025] The air passage 5 of this embodiment includes bypass passages 5a to 5c for circulating air 101 by bypassing the divided heat storage tanks 1a to 1c. Bypass passage 5a is provided between three-way valves 23 and 24, parallel to the divided heat storage tank 1a, and is used to bypass the divided heat storage tank 1a. Bypass passage 5b is provided between three-way valves 24 and 25, parallel to the divided heat storage tank 1b, and is used to bypass the divided heat storage tank 1b. Bypass passage 5c is provided between three-way valves 25 and 26, parallel to the divided heat storage tank 1c, and is used to bypass the divided heat storage tank 1c. Valve 22 is located on bypass passage 5b. In Figure 1, the air passage 5 includes a passage portion where bypass passages 5a and 5b overlap, and a passage portion where bypass passages 5b and 5c overlap.

[0026] In this embodiment, the bypass channels 5a to 5c, valve 22, and three-way valves 23 to 26 are arranged to allow switching between treating each of the divided heat storage tanks 1a to 1c as a target for air supply or as a bypass target. For example, when supplying air 101 to divided heat storage tank 1a, circulating the air 101 to bypass divided heat storage tank 1b, and circulating the air 101 to bypass divided heat storage tank 1c, the three-way valve 23 is opened between valves 12 and 14 and divided heat storage tank 1a, the three-way valve 24 is opened between divided heat storage tank 1a and bypass channel 5b, valve 22 is opened, the three-way valve 25 is closed, and the three-way valve 26 is opened between bypass channel 5c and valves 13 and 15. This makes it possible to supply air 101 only to divided heat storage tank 1a. Similarly, according to this embodiment, by controlling the opening and closing of valve 22 and three-way valves 23-26, it is possible to supply air 101 only to divided heat storage tank 1b or to divided heat storage tank 1c. Furthermore, according to this embodiment, by controlling the opening and closing of valve 22 and three-way valves 23-26, it is possible to supply air 101 to only two of the divided heat storage tanks 1a-1c.

[0027] The control unit 31 controls various operations of the heat storage system in this embodiment. The control unit 31 is, for example, a computer. The control unit 31 controls, for example, the operation of the electric heater 2, blowers 3 and 4, condensate pump 8, boiler 9, steam turbine 10, and condenser 11, as well as the opening and closing and degree of the valves 12 to 15, 22 and the three-way valves 23 to 26. This makes it possible to control the heat storage operation and heat release operation of the heat storage system in this embodiment. For example, by controlling the opening and closing of valve 22 and the three-way valves 23 to 26, the control unit 31 switches whether each of the divided heat storage tanks 1a to 1c is to be supplied with air or bypassed.

[0028] (1) Heat storage operation Figures 2 and 3 are schematic diagrams showing the operation of the heat storage system of the first embodiment during heat storage operation.

[0029] Figures 2(a) to 3(d) each show the air passage 5 from three-way valve 23 to three-way valve 26 in the heat storage system of this embodiment. Referring to Figures 2(a) to 3(d), it will be explained that during heat storage operation, valve 22 and three-way valves 23 to 26 are opened and closed in accordance with the passage of the thermocline 104, allowing air 101 to flow only along the thick line. The thermocline 104 moves from the upstream side to the downstream side in Figures 2(a) to 3(d).

[0030] Figure 2(a) shows the state at the start of the heat storage operation. In Figure 2(a), valve 22 and three-way valves 23-26 are all closed. Here, Figure 2(a) shows the state after a sufficient amount of time has passed since the end of the heat dissipation operation, and the small amount of residual heat that remains has been eliminated by heat leakage to the outside.

[0031] Next, as shown in Figure 2(b), air 101 is circulated only through the divided heat storage tank 1a, which is the uppermost part during heat storage operation, bypassing the divided heat storage tanks 1b and 1c. In Figure 2(b), the air 101 flows from left to right. The solid sensible heat storage material in the divided heat storage tank 1a experiences a temperature increase on the upstream side, and a thermocline 104 showing a steep temperature gradient in the direction of flow is formed within the divided heat storage tank 1a.

[0032] As heat storage progresses, as shown in Figure 2(c), the thermocline 104 moves within the divided heat storage tank 1a in the direction of air flow 101 and reaches the downstream side of the divided heat storage tank 1a. Then, as shown in Figure 2(d), air 101 is circulated through the divided heat storage tanks 1a and 1b, bypassing only the divided heat storage tank 1c. At this time, the thermocline 104 moves from the divided heat storage tank 1a to the divided heat storage tank 1b.

[0033] In Figure 3(a), the thermocline 104 passes through the divided heat storage tank 1a and exists only within the divided heat storage tank 1b. Then, as shown in Figure 3(b), air 101 is circulated only through the divided heat storage tank 1b, bypassing the divided heat storage tanks 1a and 1c.

[0034] Subsequently, the thermocline 104 moves within the divided heat storage tank 1b in the direction of the air flow 101, reaching the downstream side of the divided heat storage tank 1b. Then, as shown in Figure 3(c), air 101 is circulated through the divided heat storage tanks 1b and 1c, bypassing only the divided heat storage tank 1a. At this time, the thermocline 104 moves from the divided heat storage tank 1b to the divided heat storage tank 1c.

[0035] Subsequently, the thermocline 104 passes through the divided heat storage tank 1b and remains only within the divided heat storage tank 1c. Then, as shown in Figure 3(d), air 101 is circulated only through the divided heat storage tank 1c, bypassing the divided heat storage tanks 1a and 1b.

[0036] Subsequently, the heat storage operation is terminated based on the termination criteria. These termination criteria include, for example, the temperature of the air 101 flowing out of the divided heat storage tank 1c rising to the heat resistance temperature of the blower 4.

[0037] As described above, during the thermal storage operation of this embodiment, air 101 is supplied to the divided thermal storage tanks 1a to 1c one at a time or two at a time in sequence. In Figures 2(b), 2(c), 3(b), and 3(d), air 101 is supplied to one of the divided thermal storage tanks 1a to 1c. In Figures 2(d), 3(a), and 3(c), air 101 is supplied to both of the divided thermal storage tanks 1a to 1c. During the thermal storage operation of this embodiment, air 101 is supplied to the divided thermal storage tanks 1a to 1c in ascending order (1a → 1b → 1c). This control is performed by the control unit 31.

[0038] (2) Heat dissipation operation Figures 4 and 5 are schematic diagrams showing the operation of the heat storage system of the first embodiment during heat dissipation operation.

[0039] Figures 4(a) to 5(d) each show the air passage 5 from three-way valve 23 to three-way valve 26 in the heat storage system of this embodiment. Referring to Figures 4(a) to 5(d), it will be explained that during heat dissipation operation, valve 22 and three-way valves 23 to 26 are opened and closed in accordance with the passage of the thermocline 104, allowing air 101 to flow only along the thick line. The thermocline 104 moves from the upstream side to the downstream side in Figures 4(a) to 5(d).

[0040] Figure 4(a) shows the state at the start of the heat dissipation operation. In Figure 4(a), valve 22 and three-way valves 23-26 are all closed. Here, Figure 4(a) shows the state immediately after the end of the heat storage operation.

[0041] Next, as shown in Figure 4(b), air 101 is circulated only through the divided heat storage tank 1c, which is the uppermost part during heat dissipation operation, bypassing the divided heat storage tanks 1b and 1a. In Figure 4(b), the air 101 flows from right to left. The solid sensible heat storage material in the divided heat storage tank 1c experiences a temperature decrease on the upstream side, and a thermocline 104 showing a steep temperature gradient in the direction of flow is formed within the divided heat storage tank 1c.

[0042] As heat dissipation progresses, the thermocline 104 moves within the divided heat storage tank 1c in the direction of air flow 101 and reaches the downstream side of the divided heat storage tank 1c. Then, as shown in Figure 4(c), air 101 is circulated through the divided heat storage tanks 1c and 1b, bypassing only the divided heat storage tank 1a. At this time, the thermocline 104 moves from the divided heat storage tank 1c to the divided heat storage tank 1b.

[0043] Subsequently, the thermocline 104 passes through the divided heat storage tank 1c and remains only within the divided heat storage tank 1b. Then, as shown in Figure 4(d), air 101 is circulated only through the divided heat storage tank 1b, bypassing the divided heat storage tanks 1a and 1c.

[0044] Subsequently, as shown in Figure 5(a), the thermocline 104 moves within the divided heat storage tank 1b in the direction of air flow 101, reaching the downstream side of the divided heat storage tank 1b. Then, as shown in Figure 5(b), air 101 is circulated through the divided heat storage tanks 1b and 1a, bypassing only the divided heat storage tank 1c. At this time, the thermocline 104 moves from the divided heat storage tank 1b to the divided heat storage tank 1a.

[0045] In Figure 5(c), the thermocline 104 passes through the divided heat storage tank 1b and exists only within the divided heat storage tank 1a. Then, as shown in Figure 5(d), air 101 is circulated only through the divided heat storage tank 1a, bypassing the divided heat storage tanks 1c and 1b.

[0046] Subsequently, the heat dissipation operation is terminated based on termination criteria. These termination criteria include, for example, the temperature of the air 101 flowing out of the divided heat storage tank 1a dropping to the lower limit temperature of the destination where the heat was dissipated.

[0047] As described above, during the heat dissipation operation of this embodiment, air 101 is supplied to the divided heat storage tanks 1a to 1c one at a time or two at a time in sequence. In Figures 4(b), 4(d), 5(c), and 5(d), air 101 is supplied to one of the divided heat storage tanks 1a to 1c. In Figures 4(c), 5(a), and 5(b), air 101 is supplied to two of the divided heat storage tanks 1a to 1c. During the heat dissipation operation of this embodiment, air 101 is supplied to the divided heat storage tanks 1a to 1c in descending order (1c → 1b → 1a). This control is performed by the control unit 31.

[0048] Furthermore, the fluid used for heat storage and heat release may be a fluid other than air 101. Also, the heat storage material in the divided heat storage tanks 1a to 1c may be a heat storage material other than rock.

[0049] In the aforementioned second prior art, it is not possible to store heat only in the divided heat storage tank 1b, or only in the divided heat storage tank 1c, or only in the two divided heat storage tanks 1b and 1c during heat storage operation. On the other hand, in this embodiment, it is possible to store heat in any one of the divided heat storage tanks 1a to 1c, or in any two of the divided heat storage tanks 1a to 1c. This is because the bypass passages 5a to 5c, valve 22, and three-way valves 23 to 26 of this embodiment are arranged to enable such heat storage. According to this embodiment, at each point in time, it is possible to supply air 101 to the divided heat storage tank that needs heat storage, and bypass the air 101 to the divided heat storage tank that does not need heat storage. As a result, the pressure loss of air 101 is reduced by the amount that the divided heat storage tanks are bypassed, and the power consumption of the blower 3 during heat storage operation is reduced.

[0050] This is also true during heat dissipation operation. In this embodiment, it is possible to dissipate heat from any one of the divided heat storage tanks 1a to 1c, or from any two of the divided heat storage tanks 1a to 1c. In this case, air 101 can be supplied to the divided heat storage tank that is dissipating heat, and air 101 can be bypassed to the divided heat storage tank that is not dissipating heat. Therefore, it is possible to suppress the problem of insufficient heat dissipation from the divided heat storage tank 1b during heat dissipation operation, as described in the second prior art. According to this embodiment, at each point in time, air 101 can be supplied to the divided heat storage tank that needs to dissipate heat, and air 101 can be bypassed to the divided heat storage tank that does not need to dissipate heat. As a result, the pressure loss of air 101 can be reduced by the amount of air bypassed to the divided heat storage tanks, and the power consumption of the blower 4 during heat dissipation operation can be reduced.

[0051] Furthermore, the heat storage system of this embodiment may be equipped with bypass channels 5a to 5c, valves 22, and three-way valves 23 to 26 in different configurations, provided that the above-described control is possible. Also, in the heat storage system of this embodiment, the above-described control may be performed manually by a human instead of automatically by the control unit 31. In addition, the heat storage system of this embodiment may be installed in a system other than a power generation system, for example, in an air conditioning system that uses the dissipated heat for air conditioning. The same applies to the second to fifth embodiments described later.

[0052] Figure 6 is a schematic diagram showing the configuration of a modified heat storage system of the first embodiment.

[0053] Figure 6 shows the air passage 5 from the three-way valve 23 to the three-way valve 26 in the heat storage system of this modified example. The heat storage system of this modified example (Figure 6) has the same configuration as the heat storage system of this embodiment (Figure 1). However, the heat storage system of this embodiment is equipped with six temperature sensors 41 in addition to the components shown in Figure 1. These temperature sensors 41 are located near the two inlets and outlets of the divided heat storage tank 1a, near the two inlets and outlets of the divided heat storage tank 1b, and near the two inlets and outlets of the divided heat storage tank 1c.

[0054] According to this modified example, these temperature sensors 41 make it possible to detect the state (e.g., position) of the thermocline 104 of each of the divided heat storage tanks 1a to 1c. The control unit 31 may control the heat storage operation or heat release operation based on these detection results. Furthermore, the operator of the heat storage system in this modified example may determine the operation sequence, such as the switching time of each valve and each three-way valve, based on the temperature detected by these temperature sensors 41 and their operating experience.

[0055] (Second Embodiment) The heat storage system of this embodiment has the same configuration as the heat storage system of the first embodiment, as shown in Figure 1.

[0056] (1) Heat storage operation Figure 7 is a schematic diagram showing the operation of the heat storage system of the second embodiment during heat storage operation.

[0057] Figures 7(a) to 7(d) each show the air passage 5 from three-way valve 23 to three-way valve 26 in the heat storage system of this embodiment. Referring to Figures 7(a) to 7(d), it will be explained that during heat storage operation, valve 22 and three-way valves 23 to 26 are opened and closed in accordance with the passage over the thermocline 104, allowing air 101 to flow only along the thick line.

[0058] In the first embodiment, there are two cases: one in which heat is stored in one of the divided heat storage tanks 1a to 1c, and two in which heat is stored in two of the divided heat storage tanks 1a to 1c. However, even if heat is stored in only two of the divided heat storage tanks 1a to 1c, the pressure loss of the air 101 may be sufficiently high, and in such cases, it is desirable to further reduce the pressure loss. Therefore, during the heat storage operation of this embodiment, heat is always stored in only one of the divided heat storage tanks 1a to 1c, and the heat storage operation is terminated for each divided heat storage tank based on a termination criterion. In this embodiment, this termination criterion is defined as the temperature of the air 101 flowing out of each divided heat storage tank rising to the heat resistance temperature of the blower 4, and that temperature is set as the termination criterion temperature.

[0059] In this embodiment, for example, the heat storage operation described in (1) and the heat release operation described in (2) are performed alternately. At the end of the heat release operation, a thermocline 104 remains in the divided heat storage tanks 1a to 1c. In this case, the temperature distribution in the divided heat storage tanks 1a to 1c changes over time so that the temperature becomes constant in the direction of the air flow 101. In this embodiment, the heat storage operation is started immediately after the end of the heat release operation.

[0060] Figure 7(a) shows the state at the start of thermal storage operation. In Figure 7(a), valve 22 and three-way valves 23-26 are all closed. In Figure 7(a), the thermocline 104 remains in the divided thermal storage tanks 1a-1c.

[0061] Next, as shown in Figure 7(b), air 101 is circulated only through the divided heat storage tank 1a, which is the uppermost part during heat storage operation, bypassing the divided heat storage tanks 1b and 1c. In Figure 7(b), the air 101 flows from left to right. As heat storage progresses, as shown in Figure 7(b), the thermocline 104 moves within the divided heat storage tank 1a in the direction of the air 101 flow and reaches the downstream side of the divided heat storage tank 1a.

[0062] When the outlet air temperature of the divided heat storage tank 1a reaches the termination reference temperature, air 101 is allowed to flow only through the divided heat storage tank 1b, bypassing the divided heat storage tanks 1a and 1c, as shown in Figure 7(c). As heat storage progresses, the thermocline 104 moves within the divided heat storage tank 1b in the direction of the air 101 flow, as shown in Figure 7(c), and reaches the downstream side of the divided heat storage tank 1b.

[0063] When the outlet air temperature of the divided heat storage tank 1b reaches the termination reference temperature, air 101 is circulated only through the divided heat storage tank 1c, bypassing the divided heat storage tanks 1a and 1b, as shown in Figure 7(d). As heat storage progresses, the thermocline 104 moves within the divided heat storage tank 1c in the direction of air 101 flow, as shown in Figure 7(d), and reaches the downstream side of the divided heat storage tank 1c. Subsequently, when the outlet air temperature of the divided heat storage tank 1c reaches the termination reference temperature, the heat storage operation is terminated.

[0064] As described above, during the heat storage operation of this embodiment, air 101 is supplied to each of the divided heat storage tanks 1a to 1c in sequence. In Figures 7(b), 7(c), and 7(d), air 101 is supplied to one of the divided heat storage tanks 1a to 1c. During the heat storage operation of this embodiment, air 101 is supplied to the divided heat storage tanks 1a to 1c in ascending order. This control is performed by the control unit 31.

[0065] (2) Heat dissipation operation Figure 8 is a schematic diagram showing the operation of the heat storage system of the second embodiment during heat dissipation operation.

[0066] Figures 8(a) to 8(d) each show the air passage 5 from three-way valve 23 to three-way valve 26 in the heat storage system of this embodiment. Referring to Figures 8(a) to 8(d), it will be explained that during heat dissipation operation, valve 22 and three-way valves 23 to 26 are opened and closed in accordance with the passage over the thermocline 104, allowing air 101 to flow only along the thick line.

[0067] In the first embodiment, there are two cases: one in which heat is released from one of the divided heat storage tanks 1a to 1c, and another in which heat is released from two of the divided heat storage tanks 1a to 1c. However, even if heat is released from only two of the divided heat storage tanks 1a to 1c, the pressure loss of the air 101 may be sufficiently high, and in such cases, it is desirable to further reduce the pressure loss. Therefore, during the heat release operation in this embodiment, heat is always released from only one of the divided heat storage tanks 1a to 1c, and the heat release operation is terminated for each divided heat storage tank based on a termination criterion. In this embodiment, the termination criterion is defined as the temperature of the air 101 flowing out of each divided heat storage tank dropping to the lower limit temperature of the destination to which the heat has been released, and this temperature is defined as the termination criterion temperature.

[0068] In this embodiment, for example, the heat storage operation described in (1) and the heat release operation described in (2) are performed alternately. At the end of the heat storage operation, a thermocline 104 remains in the divided heat storage tanks 1a to 1c. In this case, the temperature distribution in the divided heat storage tanks 1a to 1c changes over time so that the temperature becomes constant in the direction of the air flow 101. In this embodiment, the heat release operation is started immediately after the end of the heat storage operation.

[0069] Figure 8(a) shows the state at the start of heat dissipation operation. In Figure 8(a), valve 22 and three-way valves 23-26 are all closed. In Figure 8(a), the thermocline 104 remains in the divided heat storage tanks 1a-1c.

[0070] Next, as shown in Figure 8(b), air 101 is circulated only through the divided heat storage tank 1c, which is the upstreammost part during heat dissipation operation, bypassing the divided heat storage tanks 1b and 1a. In Figure 8(b), the air 101 flows from right to left. As heat dissipation progresses, as shown in Figure 8(b), the thermocline 104 moves within the divided heat storage tank 1c in the direction of the air 101 flow and reaches the downstream side of the divided heat storage tank 1c.

[0071] When the outlet air temperature of the divided heat storage tank 1c reaches the termination reference temperature, air 101 is allowed to flow only through the divided heat storage tank 1b, bypassing the divided heat storage tanks 1c and 1a, as shown in Figure 8(c). As heat dissipation progresses, the thermocline 104 moves within the divided heat storage tank 1b in the direction of the air 101 flow, as shown in Figure 8(c), and reaches the downstream side of the divided heat storage tank 1b.

[0072] When the outlet air temperature of the divided heat storage tank 1b reaches the termination reference temperature, air 101 is circulated only through the divided heat storage tank 1a, bypassing the divided heat storage tanks 1c and 1b, as shown in Figure 8(d). As heat dissipation progresses, the thermocline 104 moves within the divided heat storage tank 1a in the direction of air 101 flow, as shown in Figure 8(d), and reaches the downstream side of the divided heat storage tank 1a. Subsequently, when the outlet air temperature of the divided heat storage tank 1a reaches the termination reference temperature, the heat storage operation is terminated.

[0073] As described above, during the heat dissipation operation of this embodiment, air 101 is supplied to each of the divided heat storage tanks 1a to 1c in sequence. In Figures 8(b), 8(c), and 8(d), air 101 is supplied to one of the divided heat storage tanks 1a to 1c. During the heat dissipation operation of this embodiment, air 101 is supplied to the divided heat storage tanks 1a to 1c in descending order. This control is performed by the control unit 31.

[0074] According to this embodiment, by supplying air 101 to the divided heat storage tanks 1a to 1c one by one in sequence, the pressure loss of the air 101 can be further reduced, and the power consumption of the blowers 3 and 4 can be further reduced.

[0075] (Third embodiment) Figure 9 is a schematic diagram showing the configuration of the heat storage system of the third embodiment.

[0076] The heat storage system of this embodiment (Figure 9) has the same configuration as the heat storage system of the first embodiment (Figure 1). However, the heat storage system of this embodiment includes three-way valves 27 and 28 instead of valve 22. Three-way valve 27 is located between bypass passage 5a, bypass passage 5b, and three-way valve 24. Three-way valve 28 is located between bypass passage 5b, bypass passage 5c, and three-way valve 25. Three-way valves 23 to 28 in this embodiment are examples of one or more valves.

[0077] In this embodiment, the bypass channels 5a to 5c and the three-way valves 23 to 28 are arranged to allow switching between treating each of the divided heat storage tanks 1a to 1c as a target for air supply or as a bypass target. For example, when supplying air 101 to divided heat storage tank 1a, circulating the air 101 to bypass divided heat storage tank 1b, and circulating the air 101 to bypass divided heat storage tank 1c, the three-way valve 23 is opened between valves 12 and 14 and divided heat storage tank 1a, the three-way valve 24 is opened between divided heat storage tank 1a and three-way valve 27, the three-way valve 27 is opened between three-way valve 24 and bypass channel 5b, the three-way valve 28 is opened between bypass channel 5b and bypass channel 5c, the three-way valve 25 is closed, and the three-way valve 26 is opened between bypass channel 5c and valves 13 and 15. This makes it possible to supply air 101 only to divided heat storage tank 1a. Similarly, according to this embodiment, by controlling the opening and closing of the three-way valves 23 to 28, it is possible to supply air 101 only to the divided heat storage tank 1b or to supply air 101 only to the divided heat storage tank 1c. Furthermore, according to this embodiment, by controlling the opening and closing of the three-way valves 23 to 28, it is possible to supply air 101 to only two of the divided heat storage tanks 1a to 1c.

[0078] According to this embodiment, by controlling the opening and closing of the three-way valves 23 to 28 with the control unit 31, it is possible to perform heat storage operation and heat release operation similar to that of the first embodiment. In this embodiment, instead of performing heat storage operation and heat release operation similar to that of the first embodiment, heat storage operation and heat release operation similar to that of the second embodiment may be performed.

[0079] (Fourth embodiment) Figure 10 is a schematic diagram showing the configuration of the heat storage system of the fourth embodiment.

[0080] The heat storage system of this embodiment (Figure 10) has the same configuration as the heat storage system of the first embodiment (Figure 1). However, in addition to the components shown in Figure 1, the heat storage system of this embodiment includes valve 22', three-way valve 23', three-way valve 24', three-way valve 25', and three-way valve 26'. Valves 22' and three-way valves 23' to 26' are arranged on the air passage 5 in the same arrangement as valve 22 and three-way valves 23 to 26. Valves 22, 22', and three-way valves 23 to 26, 23' to 26' are examples of one or more valves. Furthermore, valve 22 and three-way valves 23 to 26 are examples of one or more first valves, and valves 22' and three-way valves 23' to 26' are examples of one or more second valves.

[0081] The heat storage system of this embodiment further comprises a heat storage tank 1'. The heat storage tank 1' includes a divided heat storage tank 1a', a divided heat storage tank 1b', and a divided heat storage tank 1c'. The divided heat storage tanks 1a' to 1c' are arranged on the air passage 5 in the same arrangement as the divided heat storage tanks 1a to 1c. The heat storage system of this embodiment comprises two sets of divided heat storage tanks, divided heat storage tanks 1a to 1c and divided heat storage tanks 1a' to 1c'. The divided heat storage tanks 1a to 1c are examples of the first to first Na heat storage tanks (Na is an integer of 2 or more) of the first set, and the divided heat storage tanks 1a to 1c are examples of the second set of first to first Nb heat storage tanks (Nb is an integer of 2 or more). Furthermore, each of the divided heat storage tanks 1a to 1c is an example of an arbitrary Ka heat storage tank (where Ka is any integer between 1 and Na), and each of the divided heat storage tanks 1a' to 1c' is an example of an arbitrary Kb heat storage tank (where Kb is any integer between 1 and Nb).

[0082] The heat storage system of this embodiment further comprises bypass channels 5a', 5b', and 5c' within the air channel 5. Bypass channels 5a' to 5c' are included within the air channel 5 in the same layout as bypass channels 5a to 5c. Bypass channels 5a to 5c are examples of first bypass channels, and bypass channels 5a' to 5c' are examples of second bypass channels.

[0083] In this embodiment, the heat storage tank 1' is divided into two or more divided heat storage tanks in the direction of the air flow 101, and in Figure 10, it is divided into three divided heat storage tanks 1a' to 1c'. Although the heat storage tank 1' is divided into three in Figure 10, it may be divided into N other units. The divided heat storage tanks 1a' to 1c' are connected in series with respect to the air flow 101. In addition, the divided heat storage tanks 1a' to 1c' are connected in parallel with the divided heat storage tanks 1a to 1c with respect to the air flow 101. Each of the divided heat storage tanks 1a' to 1c' contains a heat storage material. The heat storage material is a solid sensible heat storage material, such as rock.

[0084] The air passage 5 of this embodiment includes bypass passages 5a' to 5c' for circulating air 101 by bypassing the divided heat storage tanks 1a' to 1c'. Bypass passage 5a' is provided parallel to the divided heat storage tank 1a' between three-way valves 23' and 24' and is used to bypass the divided heat storage tank 1a'. Bypass passage 5b' is provided parallel to the divided heat storage tank 1b' between three-way valves 24' and 25' and is used to bypass the divided heat storage tank 1b'. Bypass passage 5c' is provided parallel to the divided heat storage tank 1c' between three-way valves 25' and 26' and is used to bypass the divided heat storage tank 1c'. Valve 22' is located on the bypass passage 5b'.

[0085] In this embodiment, the bypass channels 5a' to 5c', valve 22', and three-way valves 23' to 26' are arranged to allow switching between treating each of the divided heat storage tanks 1a' to 1c' as a target for air supply or as a bypass target. According to this embodiment, by controlling the opening and closing of valve 22' and three-way valves 23' to 26', it is possible to supply air 101 to only one of the divided heat storage tanks 1a' to 1c', or to supply air 101 to only two of the divided heat storage tanks 1a to 1c.

[0086] According to this embodiment, by controlling the opening and closing of valve 22 and three-way valves 23-26 with the control unit 31, it is possible to perform heat storage and heat release operations for the divided heat storage tanks 1a-1c in the same manner as in the first embodiment. Furthermore, according to this embodiment, by controlling the opening and closing of valve 22' and three-way valves 23'-26' with the control unit 31, it is possible to perform heat storage and heat release operations for the divided heat storage tanks 1a'-1c' in the same manner as in the first embodiment. In this embodiment, instead of performing heat storage and heat release operations in the same manner as in the first embodiment, heat storage and heat release operations in the same manner as in the second embodiment may be performed.

[0087] In this embodiment, the heat storage system branches the air 101 into two separate lines: one for heat storage tank 1 and the other for heat storage tank 1'. The air 101 for heat storage tank 1 is used for the divided heat storage tanks 1a to 1c, and the air 101 for heat storage tank 1' is used for the divided heat storage tanks 1a' to 1c'. The used air 101 from the former and the latter lines are then combined. In this embodiment, during heat storage operation, the heat storage system may supply air 101 to both heat storage tanks 1 and 1', or to only one of them. In addition, during heat release operation, the heat storage system may supply air 101 to both heat storage tanks 1 and 1', or to only one of them. According to this embodiment, by using two sets of divided heat storage tanks 1a to 1c and 1a' to 1c', it is possible to improve the freedom and flexibility of operation.

[0088] The heat storage system of this embodiment comprises two sets of divided heat storage tanks, namely divided heat storage tanks 1a to 1c and divided heat storage tanks 1a' to 1c', but it may also comprise one or more sets of divided heat storage tanks. In this case, each of the additional sets of divided heat storage tanks can be configured in the same way as divided heat storage tanks 1a to 1c and divided heat storage tanks 1a' to 1c'.

[0089] (Fifth embodiment) Figure 11 is a schematic diagram showing the configuration of the heat storage system of the fifth embodiment.

[0090] Figure 11 shows the air passage 5 from three-way valve 23 to three-way valve 26 in the heat storage system of this embodiment. The heat storage system of this embodiment (Figure 11) has the same configuration as the heat storage system of the first embodiment (Figure 1). However, the heat storage system of this embodiment includes components described later in addition to the components shown in Figure 1.

[0091] In this embodiment, the heat storage system can release heat only from the selected heat storage tank 1a to 1c by using bypass channels 5a to 5c during heat release operation. In such a heat storage system, the heat storage state is often maintained for a long period of time between the end of heat storage operation and the start of heat release operation. In this case, even if the heat storage tanks 1a to 1c are surrounded by insulating material, the stored heat will gradually leak out of the tanks 1a to 1c to the outside world, such as pipes, the ground, or the atmosphere, over a long period of time.

[0092] Figure 11 shows that during the heat dissipation operation, only the divided heat storage tank 1a is dissipating heat, while the divided heat storage tanks 1b and 1c are experiencing a temperature drop due to heat leakage. The temperature 111 immediately after the heat storage operation has changed to the temperature 112 immediately before the heat storage operation. If, during the subsequent heat storage operation, all divided heat storage tanks 1a to 1c are sufficiently heated, the amount of heat heated to divided heat storage tanks 1b and 1c is significantly smaller than the amount of heat heated to divided heat storage tank 1a.

[0093] Therefore, as shown in Figures 12(a) to 13(c), the heat storage system of this embodiment is equipped with a side flow inlet channel 5d and a side flow outlet channel 5e within the air flow channel 5, with valves 51, 53, and 55 on the side flow inlet channel 5d and valves 52, 54, and 56 on the side flow outlet channel 5e. The opening and closing of valves 51 to 56 are controlled by the control unit 31. Valves 51, 53, and 55 are examples of one or more side flow inlet valves. Valves 52, 54, and 56 are examples of one or more side flow outlet valves. Figures 12 and 13 are schematic diagrams showing the operation of the heat storage system of the fifth embodiment during heat storage operation.

[0094] In Figures 12(a) to 13(c), the side of each valve that allows flow is shown in white, and the side that does not allow flow is shown in black. This is the same for each three-way valve. Below, Figure 12(a) will be explained, followed by Figures 12(b), 12(c), 13(a), 13(b), and 13(c).

[0095] Figure 12(a) shows valves 51, 53, and 55 located on the side flow inflow channel 5d, and valves 52, 54, and 56 located on the side flow outflow channel 5e. Valve 51 is used to allow air 101 to flow into the divided heat storage tank 1a from upstream of the three-way valve 23. Valve 53 is used to allow air 101 to flow into the divided heat storage tank 1b from upstream of the three-way valve 23. Valve 55 is used to allow air 101 to flow into the divided heat storage tank 1c from upstream of the three-way valve 23. Valve 52 is used to allow air 101 to flow out from the divided heat storage tank 1a downstream of the three-way valve 26. Valve 54 is used to allow air 101 to flow out from the divided heat storage tank 1b downstream of the three-way valve 26. Valve 56 is used to allow air 101 to flow out from the divided heat storage tank 1c downstream of the three-way valve 26. The air 101 flowing through the side inflow channel 5d is called branch air 113. The air 101 flowing through the side outflow channel 5e is called branch air 114.

[0096] In Figure 12(a), the airflow channel 5 includes bypass channels 5a to 5c, a side flow inflow channel 5d, a side flow outflow channel 5d, and other parts. This "other parts" is the main flow channel that supplies the main flow of air 101 to the divided heat storage tanks 1a to 1c, and the divided heat storage tanks 1a to 1c are connected in series with each other. The bypass channels 5a to 5c allow the main flow of air 101 to circulate so as to bypass one or more of the divided heat storage tanks 1a to 1c. The side flow inflow channel 5d is provided between the main flow channel and the divided heat storage tanks 1a to 1c, and allows a side flow of air 101 (branched air 113) to flow from the main flow channel into the divided heat storage tanks 1a to 1c. The side flow outflow channel 5e is provided between the divided heat storage tanks 1a to 1c and the main flow channel, and allows a side flow of air 101 (branched air 114) to flow out from the divided heat storage tanks 1a to 1c into the main flow channel. Valves 51-56 can switch whether or not to allow a side flow of air 101 (branched air 113) to flow into a particular divided heat storage tank among the divided heat storage tanks 1a-1c when the main flow of air 101 is not supplied to that tank, and whether or not to allow a side flow of air 101 (branched air 114) to flow out of that divided heat storage tank. This divided heat storage tank is an example of any M heat storage tank (M is any integer from 1 to N) among the 1st to Nth heat storage tanks (N is an integer of 2 or more).

[0097] In Figure 12(a), air 101 is circulated as the main flow through the divided heat storage tank 1a, and normal heat storage is carried out in the divided heat storage tank 1a. Upstream of the divided heat storage tank 1a, the air 101 is branched, and the branched air 113 is circulated through the side flow inlet channel 5d and flows into the divided heat storage tank 1b. The divided heat storage tank 1b is replenished and stored by the branched air 113 to compensate for the amount of heat that has leaked out. The branched air 114 that has flowed out of the divided heat storage tank 1b flows through the side flow outlet channel 5e and flows out to a position downstream of the divided heat storage tank 1c. Similarly, the divided heat storage tank 1c is replenished and stored by the branched air 113 to compensate for the amount of heat that has leaked out. The flow rates of the branched air 113 and 114 circulating through the divided heat storage tanks 1b and 1c are sufficiently small compared to the flow rate of air 101 circulating through the divided heat storage tank 1a. In other words, a large amount of heat is stored in the divided heat storage tank 1a using a large amount of air 101, while a small amount of heat is stored in the divided heat storage tanks 1b and 1c using small amounts of branched air 113 and 114.

[0098] If normal heat storage is performed in the divided heat storage tank 1a, heat storage for heat leakage is performed in the divided heat storage tank 1b, and no heat storage is performed in the divided heat storage tank 1c, then valves 51 to 56 are opened and closed as shown in Figure 12(b).

[0099] Furthermore, if normal heat storage is performed in the divided heat storage tank 1b, heat storage for heat leakage is performed in the divided heat storage tank 1a, and no heat storage is performed in the divided heat storage tank 1c, valves 51 to 56 are opened and closed as shown in Figure 12(c).

[0100] Furthermore, if normal heat storage is performed in the divided heat storage tank 1b and heat storage for heat leakage is performed in the divided heat storage tanks 1a and 1c, valves 51 to 56 are opened and closed as shown in Figure 13(a).

[0101] Furthermore, if normal heat storage is performed in the divided heat storage tank 1c and heat storage for heat leakage is performed in the divided heat storage tanks 1a and 1b, valves 51 to 56 are opened and closed as shown in Figure 13(b).

[0102] Furthermore, if normal heat storage is performed in the divided heat storage tank 1a, and no heat storage is performed in the divided heat storage tanks 1b and 1c, valves 51 to 56 are opened and closed as shown in Figure 13(c).

[0103] According to this embodiment, it is possible to reduce the pressure loss of air 101 in the divided heat storage tank that stores a large amount of heat. According to this embodiment, by circulating only small amounts of branched air 113 and 114 in the divided heat storage tank that replenishes the heat leakage, it is possible to reduce the pressure loss of branched air 113 and 114. As a result, the power consumption of the blower 3 during heat storage operation is reduced.

[0104] The heat storage system of this embodiment may also be equipped with a plurality of temperature sensors 41, as described in the modified example of the first embodiment (Figure 6). In this case, these temperature sensors 41 can detect the heat leakage and heat replenishment status of each of the divided heat storage tanks 1a to 1c, and the detection results may be used in operation as in the modified example described above.

[0105] Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel system described herein can be implemented in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the system described herein without departing from the spirit of the invention. The appended claims and equivalents are intended to include such forms and modifications that are included in the scope and spirit of the invention. [Explanation of Symbols]

[0106] 1: Heat storage tank, 1a: Split heat storage tank, 1b: Split heat storage tank, 1c: Split heat storage tank, 1': heat storage tank, 1a': split heat storage tank, 1b': split heat storage tank, 1c': split heat storage tank, 2: Electric heater, 3: Blower, 4: Blower, 5: Air passage, 5a: Bypass channel, 5b: Bypass channel, 5c: Bypass channel, 5a': Bypass channel, 5b': Bypass channel, 5c': Bypass channel, 5d: Side flow inflow channel, 5e: Side flow outflow channel, 6: Water channel, 7: Steam channel, 8: Condensate pump, 9: Boiler, 10: Steam turbine 11: Condenser, 12: Valve, 13: Valve, 14: Valve, 15: Valve, 16: Valve, 17: Valve, 18: Valve, 19: Three-way valve, 20: Three-way valve, 21: Three-way valve, 22: Valve, 22': Valve, 23: Three-way valve, 23': Three-way valve, 24: Three-way valve, 24': Three-way valve, 25: Three-way valve, 25': Three-way valve, 26: Three-way valve, 26': Three-way valve, 27: Three-way valve, 28: Three-way valve, 31: Control unit, 41: Temperature sensor, 51: Valve, 52: Valve, 53: Valve, 54: Valve, 55: Valve, 56: Valve, 101: air, 102: water, 103: steam, 104: thermocline 111: Temperature immediately after heat storage operation, 112: Temperature immediately before heat storage operation, 113: Branched air, 114: Branched air

Claims

1. The first to Nth heat storage tanks (where N is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first to nth heat storage tanks, the fluid channel including a bypass channel that allows the heat transfer fluid to flow so as to bypass one or more of the first to nth heat storage tanks, One or more temperature sensors for detecting the state of the thermocline in the first to nth heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any K heat storage tank (where K is any integer from 1 to N) among the first to N heat storage tanks, or circulating the heat transfer fluid so as to bypass the K heat storage tank. The first to the nth heat storage tanks are connected in series with each other in the order of the first to the nth heat storage tanks. The control unit controls the opening and closing of one or more valves, during heat storage operation, After supplying the heat transfer fluid only to the K heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the K heat storage tank has reached the outlet of the K heat storage tank, the heat transfer fluid is supplied only to the K heat storage tank and the K+1 heat storage tank. After supplying the heat transfer fluid only to the K heat storage tank and the K+1 heat storage tank, if one or more temperature sensors detect that the thermocline that has reached the outlet of the K heat storage tank has passed the outlet of the K heat storage tank, the heat transfer fluid is supplied only to the K+1 heat storage tank. A heat storage system characterized by [this feature].

2. The first to Nth heat storage tanks (where N is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first to nth heat storage tanks, the fluid channel including a bypass channel that allows the heat transfer fluid to flow so as to bypass one or more of the first to nth heat storage tanks, One or more temperature sensors for detecting the state of the thermocline in the first to nth heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any K heat storage tank (where K is any integer from 1 to N) among the first to N heat storage tanks, or circulating the heat transfer fluid so as to bypass the K heat storage tank. The first to the nth heat storage tanks are connected in series with each other in the order of the first to the nth heat storage tanks. The control unit controls the opening and closing of one or more valves, thereby enabling heat dissipation operation. After supplying the heat transfer fluid only to the K heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the K heat storage tank has reached the outlet of the K heat storage tank, the heat transfer fluid is supplied only to the K heat storage tank and the K-1 heat storage tank. After supplying the heat transfer fluid only to the K heat storage tank and the K-1 heat storage tank, if one or more temperature sensors detect that the thermocline that has reached the outlet of the K heat storage tank has passed the outlet of the K heat storage tank, the heat transfer fluid is supplied only to the K-1 heat storage tank. A heat storage system characterized by [this feature].

3. The first to Nth heat storage tanks (where N is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first to nth heat storage tanks, the fluid channel including a bypass channel that allows the heat transfer fluid to flow so as to bypass one or more of the first to nth heat storage tanks, One or more temperature sensors for detecting the state of the thermocline in the first to nth heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any K heat storage tank (where K is any integer from 1 to N) among the first to N heat storage tanks, or circulating the heat transfer fluid so as to bypass the K heat storage tank. The first to the nth heat storage tanks are connected in series with each other in the order of the first to the nth heat storage tanks. The control unit controls the opening and closing of one or more valves, during heat storage operation, After supplying the heat transfer fluid only to the K heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the K heat storage tank has reached the outlet of the K heat storage tank, the heat transfer fluid is supplied only to the K+1 heat storage tank. A heat storage system characterized by [this feature].

4. The first to Nth heat storage tanks (where N is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first to nth heat storage tanks, the fluid channel including a bypass channel that allows the heat transfer fluid to flow so as to bypass one or more of the first to nth heat storage tanks, One or more temperature sensors for detecting the state of the thermocline in the first to nth heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any K heat storage tank (where K is any integer from 1 to N) among the first to N heat storage tanks, or circulating the heat transfer fluid so as to bypass the K heat storage tank. The first to the nth heat storage tanks are connected in series with each other in the order of the first to the nth heat storage tanks. The control unit controls the opening and closing of one or more valves, thereby enabling heat dissipation operation. After supplying the heat transfer fluid only to the K heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the K heat storage tank has reached the outlet of the K heat storage tank, the heat transfer fluid is supplied only to the K-1 heat storage tank. A heat storage system characterized by [this feature].

5. The heat storage system according to claim 1 or 2, characterized in that the control unit controls the opening and closing of one or more valves to sequentially supply the heat transport fluid to the first to nth heat storage tanks one or two at a time during heat storage operation or heat release operation.

6. The heat storage system according to claim 3 or 4, characterized in that the control unit controls the opening and closing of one or more valves to supply the heat transfer fluid to the first to nth heat storage tanks one by one in sequence during heat storage operation or heat release operation.

7. The heat storage system according to any one of claims 1 to 4, characterized in that the control unit controls the opening and closing of one or more valves to supply the heat transfer fluid to the first to the Nth heat storage tanks in ascending order during heat storage operation, and to supply the heat transfer fluid to the first to the Nth heat storage tanks in descending order during heat release operation.

8. A first fluid transport unit that transports the heat transport fluid to the first to nth heat storage tanks during heat storage operation, A second fluid transport unit transports the heat transport fluid to the first to nth heat storage tanks during heat dissipation operation, A heat storage system according to any one of claims 1 to 4, further comprising the above.

9. The aforementioned fluid channel is The first to the nth heat storage tanks are connected in series with respect to a main flow path that supplies the main flow of the heat transfer fluid to the first to the nth heat storage tanks, A bypass channel for circulating the main flow of the heat transfer fluid so as to bypass one or more of the first to nth heat storage tanks, A side flow inflow channel is provided between the main flow channel and the first to Nth heat storage tanks, and allows a side flow of the heat transport fluid to flow from the main flow channel into the first to Nth heat storage tanks, A side flow outflow channel is provided between the first to nth heat storage tanks and the main flow channel, and allows a side flow of the heat transport fluid to flow out from the first to nth heat storage tanks into the main flow channel, One or more side-flow inlet valves are provided in the side-flow inlet channel, The system comprises one or more side-flow outlet valves provided in the side-flow outlet channel, The heat storage system according to any one of claims 1 to 4, characterized in that the control unit controls the opening and closing of one or more side-flow inlet valves and one or more side-flow outlet valves, and during heat storage operation, with respect to any M heat storage tank (M is any integer from 1 to N) among the first to N heat storage tanks, it switches whether or not to allow the side flow of the heat transfer fluid to flow into the M heat storage tank and whether or not to allow the side flow of the heat transfer fluid to flow out of the M heat storage tank when the main flow of the heat transfer fluid is not supplied to the M heat storage tank.

10. A first set of first to second Na heat storage tanks (where Na is an integer of 2 or more) are connected in series with each other and use a solid sensible heat storage material as the heat storage material, A second set of first to Nb heat storage tanks (where Nb is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first set of first to first Na heat storage tanks and the second set of first to first Nb heat storage tanks, comprising: a first bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Na heat storage tanks of the first set; and a second bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Nb heat storage tanks of the second set; One or more temperature sensors for detecting the state of the thermocline in the first set of first to second Na heat storage tanks and the second set of first to second Nb heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any Ka heat storage tank (Ka is any integer from 1 to Na) among the first set of first to Na heat storage tanks and any Kb heat storage tank (Kb is any integer from 1 to Nb) among the second set of first to Nb heat storage tanks, and to switch between supplying the heat transfer fluid to the Kb heat storage tank and to flow the heat transfer fluid so as to bypass the Kb heat storage tank, The first set of first to second sodium heat storage tanks are connected in series with each other in the order of first to second sodium heat storage tanks. The second set of first to Nb heat storage tanks are connected in series with each other in the order of first to Nb heat storage tanks. The control unit controls the opening and closing of one or more valves, during heat storage operation, After supplying the heat transfer fluid only to the Ka heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Ka heat storage tank has reached the outlet of the Ka heat storage tank, the heat transfer fluid is supplied only to the Ka heat storage tank and the Ka+1 heat storage tank. After supplying the heat transfer fluid only to the Ka heat storage tank and the Ka+1 heat storage tank, if one or more temperature sensors detect that the thermocline that has reached the outlet of the Ka heat storage tank has passed the outlet of the Ka heat storage tank, the heat transfer fluid is supplied only to the Ka+1 heat storage tank. After supplying the heat transfer fluid only to the Kb heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Kb heat storage tank has reached the outlet of the Kb heat storage tank, the heat transfer fluid is supplied only to the Kb heat storage tank and the Kb+1 heat storage tank. After supplying the heat transfer fluid only to the Kb heat storage tank and the Kb+1 heat storage tank, if one or more temperature sensors detect that the thermocline that has reached the outlet of the Kb heat storage tank has passed the outlet of the Kb heat storage tank, the heat transfer fluid is supplied only to the Kb+1 heat storage tank. A heat storage system characterized by [this feature].

11. A first set of first to second Na heat storage tanks (where Na is an integer of 2 or more) are connected in series with each other and use a solid sensible heat storage material as the heat storage material, A second set of first to Nb heat storage tanks (where Nb is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first set of first to first Na heat storage tanks and the second set of first to first Nb heat storage tanks, comprising: a first bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Na heat storage tanks of the first set; and a second bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Nb heat storage tanks of the second set; One or more temperature sensors for detecting the state of the thermocline in the first set of first to second Na heat storage tanks and the second set of first to second Nb heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any Ka heat storage tank (Ka is any integer from 1 to Na) among the first set of first to Na heat storage tanks and any Kb heat storage tank (Kb is any integer from 1 to Nb) among the second set of first to Nb heat storage tanks, and to switch between supplying the heat transfer fluid to the Kb heat storage tank and to flow the heat transfer fluid so as to bypass the Kb heat storage tank, The first set of first to second sodium heat storage tanks are connected in series with each other in the order of first to second sodium heat storage tanks. The second set of first to Nb heat storage tanks are connected in series with each other in the order of first to Nb heat storage tanks. The control unit controls the opening and closing of one or more valves, thereby enabling heat dissipation operation. After supplying the heat transfer fluid only to the Ka heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Ka heat storage tank has reached the outlet of the Ka heat storage tank, the heat transfer fluid is supplied only to the Ka heat storage tank and the Ka-1 heat storage tank. After supplying the heat transfer fluid only to the Ka heat storage tank and the Ka-1 heat storage tank, if one or more temperature sensors detect that the thermocline that has reached the outlet of the Ka heat storage tank has passed the outlet of the Ka heat storage tank, the heat transfer fluid is supplied only to the Ka-1 heat storage tank. After supplying the heat transfer fluid only to the Kb heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Kb heat storage tank has reached the outlet of the Kb heat storage tank, the heat transfer fluid is supplied only to the Kb heat storage tank and the Kb-1 heat storage tank. After supplying the heat transfer fluid only to the Kb heat storage tank and the Kb-1 heat storage tank, if one or more temperature sensors detect that the thermocline that has reached the outlet of the Kb heat storage tank has passed the outlet of the Kb heat storage tank, the heat transfer fluid is supplied only to the Kb-1 heat storage tank. A heat storage system characterized by [this feature].

12. A first set of first to second Na heat storage tanks (where Na is an integer of 2 or more) are connected in series with each other and use a solid sensible heat storage material as the heat storage material, A second set of first to Nb heat storage tanks (where Nb is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first set of first to first Na heat storage tanks and the second set of first to first Nb heat storage tanks, comprising: a first bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Na heat storage tanks of the first set; and a second bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Nb heat storage tanks of the second set; One or more temperature sensors for detecting the state of the thermocline in the first set of first to second Na heat storage tanks and the second set of first to second Nb heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any Ka heat storage tank (Ka is any integer from 1 to Na) among the first set of first to Na heat storage tanks and any Kb heat storage tank (Kb is any integer from 1 to Nb) among the second set of first to Nb heat storage tanks, and to switch between supplying the heat transfer fluid to the Kb heat storage tank and to flow the heat transfer fluid so as to bypass the Kb heat storage tank, The first set of first to second sodium heat storage tanks are connected in series with each other in the order of first to second sodium heat storage tanks. The second set of first to Nb heat storage tanks are connected in series with each other in the order of first to Nb heat storage tanks. The control unit controls the opening and closing of one or more valves, during heat storage operation, After supplying the heat transfer fluid only to the Ka heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Ka heat storage tank has reached the outlet of the Ka heat storage tank, the heat transfer fluid is supplied only to the Ka+1 heat storage tank. After supplying the heat transfer fluid only to the Kb heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Kb heat storage tank has reached the outlet of the Kb heat storage tank, the heat transfer fluid is supplied only to the Kb+1 heat storage tank. A heat storage system characterized by [this feature].

13. A first set of first to second Na heat storage tanks (where Na is an integer of 2 or more) are connected in series with each other and use a solid sensible heat storage material as the heat storage material, A second set of first to Nb heat storage tanks (where Nb is an integer of 2 or more) are connected in series to each other and use a solid sensible heat storage material as the heat storage material, A fluid channel for supplying heat transfer fluid to the first set of first to first Na heat storage tanks and the second set of first to first Nb heat storage tanks, comprising: a first bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Na heat storage tanks of the first set; and a second bypass channel through which the heat transfer fluid flows so as to bypass one or more of the first to first Nb heat storage tanks of the second set; One or more temperature sensors for detecting the state of the thermocline in the first set of first to second Na heat storage tanks and the second set of first to second Nb heat storage tanks, One or more valves provided in the fluid passage, The system comprises a control unit that controls the opening and closing of one or more of the aforementioned valves, The control unit controls the opening and closing of one or more valves to switch between supplying the heat transfer fluid to any Ka heat storage tank (Ka is any integer from 1 to Na) among the first set of first to Na heat storage tanks and any Kb heat storage tank (Kb is any integer from 1 to Nb) among the second set of first to Nb heat storage tanks, and to switch between supplying the heat transfer fluid to the Kb heat storage tank and to flow the heat transfer fluid so as to bypass the Kb heat storage tank, The first set of first to second sodium heat storage tanks are connected in series with each other in the order of first to second sodium heat storage tanks. The second set of first to Nb heat storage tanks are connected in series with each other in the order of first to Nb heat storage tanks. The control unit controls the opening and closing of one or more valves, thereby enabling heat dissipation operation. After supplying the heat transfer fluid only to the Ka heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Ka heat storage tank has reached the outlet of the Ka heat storage tank, the heat transfer fluid is supplied only to the Ka-1 heat storage tank. After supplying the heat transfer fluid only to the Kb heat storage tank, if one or more temperature sensors detect that the thermocline moving from the inlet to the outlet of the Kb heat storage tank has reached the outlet of the Kb heat storage tank, the heat transfer fluid is supplied only to the Kb-1 heat storage tank. A heat storage system characterized by [this feature].

14. The thermal storage system according to any one of claims 10 to 13, characterized in that the second set of first to Nb thermal storage tanks is connected in parallel with the first set of first to Na thermal storage tanks.

15. The one or more valves mentioned above are One or more first valves are provided to allow switching between supplying the heat transfer fluid to the Ka heat storage tank or circulating the heat transfer fluid so as to bypass the Ka heat storage tank, One or more second valves are provided to allow switching between supplying the heat transfer fluid to the Kb heat storage tank or circulating the heat transfer fluid so as to bypass the Kb heat storage tank, Includes, The control unit controls the opening and closing of one or more first valves to switch between supplying the heat transfer fluid to the Ka heat storage tank or circulating the heat transfer fluid so as to bypass the Ka heat storage tank. The control unit controls the opening and closing of one or more second valves to switch between supplying the heat transfer fluid to the Kb heat storage tank or circulating the heat transfer fluid so as to bypass the Kb heat storage tank. A heat storage system according to any one of claims 10 to 13, characterized by the fact that...

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