Energy accumulation device

Abstract

To effectively use exhaust heat.SOLUTION: An energy accumulation device includes: a first heat exchanger that exchanges heat between gas and solid particles; a gas supply section that includes a blower and supplies gas to the first heat exchanger; a heater that heats gas to be supplied from the gas supply section to the first heat exchanger by consuming electric power; a solid-gas separator that performs solid-gas separation of a solid-gas mixture discharged from the first heat exchanger; a high temperature tank and a low temperature tank for storing the solid particles that have undergone the solid-gas separation; a high temperature particle supply pipe that communicates inside of the high temperature tank with inside of the first heat exchanger; a second heat exchanger that exchanges heat between the solid particles supplied from the low temperature tank and the gas that has undergone the solid-gas separation; a gas passage section for causing the gas separated by the solid-gas separator to pass through inside of the accommodation chamber of the second heat exchanger; and a low temperature particle supply pipe that communicates inside of the low temperature tank with the accommodation chamber of the second heat exchanger and communicates inside of the accommodation chamber with the inside of the first heat exchanger. The gas supply section supplies the gas that has undergone heat exchange through the second heat exchanger to the first heat exchanger.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an energy storage device.

Background Art

[0002] The amount of generated electric power (hereinafter referred to as "generated power amount") and the amount of consumed electric power (hereinafter referred to as "required power amount") do not always match. For this reason, there may be a power surplus where the generated power amount exceeds the required power amount, or a power shortage where the generated power amount is less than the required power amount. In particular, in power generation using renewable energy such as wind power generation and solar power generation, it is difficult to adjust the generated power amount, so there is a large amount of surplus or shortage of electric power.

[0003] Therefore, when a power surplus occurs, the surplus power is consumed to heat solid particles and heat is stored in the solid particles. When a power shortage occurs, a technology has been developed to convert the heat stored in the solid particles into electric power (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the technology of Patent Document 1 above, development of a technology for efficiently using exhaust heat is desired.

[0006] In view of such problems, an object of the present disclosure is to provide an energy storage device capable of efficiently using exhaust heat.

Means for Solving the Problems

[0007] In order to solve the above problems, an energy storage device according to one aspect of the present disclosure has a first heat exchanger that is supplied with gas from a gas supply port formed on the bottom surface or lower part, supplied with solid particles from above the gas supply port, and exchanges heat between the gas and the solid particles, a gas supply unit that includes a blower and supplies gas to the first heat exchanger, a heater that consumes electric power to heat either one or both of the gas supplied from the gas supply unit to the first heat exchanger and the gas in the first heat exchanger, a solid-gas separator that separates the solid-gas mixture discharged from the first heat exchanger, a high-temperature tank that stores the solid particles separated by the solid-gas separator, a high-temperature particle supply pipe that communicates the inside of the high-temperature tank with the inside of the first heat exchanger, a low-temperature tank that stores solid particles separated by the solid-gas separator and having a lower temperature than the solid particles stored in the high-temperature tank, a second heat exchanger that has a storage chamber smaller in volume than the low-temperature tank and accommodates the solid particles supplied from the low-temperature tank, and exchanges heat between the solid particles and the gas separated by the solid-gas separator, a gas passage portion that allows the gas separated by the solid-gas separator to pass through the storage chamber of the second heat exchanger, and a low-temperature particle supply pipe that includes a first particle supply pipe that communicates the inside of the low-temperature tank with the inside of the storage chamber of the second heat exchanger and a second particle supply pipe that communicates the inside of the storage chamber with the inside of the first heat exchanger, and the gas supply unit supplies the gas after heat exchange by the second heat exchanger to the first heat exchanger.

[0008] Further, the volume of the storage chamber of the second heat exchanger may be determined such that the temperature of the gas after heat exchange by the second heat exchanger is equal to or lower than the heat-resistant temperature of the blower of the gas supply unit.

[0009] Further, the gas passage portion may form a fluidized bed of solid particles in the storage chamber by supplying the gas separated by the solid-gas separator from the bottom surface or lower part of the storage chamber of the second heat exchanger.

[0010] Further, the energy storage device further includes a water vapor generation unit that exchanges heat between the solid particles separated by the solid-gas separator and water to cool the solid particles and heat the water to generate water vapor, and the low-temperature tank may store the solid particles after heat exchange by the water vapor generation unit.

[0011] The energy storage device further includes a gas supply unit and a control unit that controls the heater. The control unit executes one of a plurality of operation modes, and the plurality of operation modes include a heat storage mode and a heat dissipation mode. In the heat storage mode, the gas supply unit is controlled to supply gas to the first heat exchanger, power is supplied to the heater to heat the gas, solid particles stored in the low-temperature tank are supplied to the accommodation chamber of the second heat exchanger, the solid particles are supplied from the accommodation chamber of the second heat exchanger to the first heat exchanger, the solid particles are heated by the gas in the first heat exchanger, the solid particles separated by the solid-gas separator are supplied to the high-temperature tank, and the gas separated by the solid-gas separator is supplied to the accommodation chamber of the second heat exchanger. In the heat dissipation mode, solid particles are supplied from the high-temperature tank to the first heat exchanger, the heater is stopped, the gas supply unit is controlled to supply gas to the first heat exchanger, the gas is heated by the solid particles in the first heat exchanger, the solid particles separated by the solid-gas separator are supplied to the water vapor generation unit, and the solid particles may be supplied from the water vapor generation unit to the low-temperature tank.

Advantages of the Invention

[0012] According to the present disclosure, it is possible to efficiently utilize exhaust heat.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for easy understanding and do not limit the present disclosure unless otherwise specified. In this specification and the drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to avoid redundant description. Further, elements not directly related to the present disclosure are not shown in the drawings.

[0015] [Energy storage device 100] FIG. 1 is a diagram for explaining an energy storage device 100 according to this embodiment. As shown in FIG. 1, the energy storage device 100 includes a gas supply unit 110, a heating chamber 120, a first heat exchanger 130, a solid-gas separator 140, a switching unit 150, a high-temperature tank 160, a high-temperature particle supply unit 170, a low-temperature tank 180, a low-temperature particle supply unit 190, a second heat exchanger 200, a gas passage unit 210, a heat utilization device 232, a second water vapor generation unit 240, a heat utilization device 254, and a control unit 260. In FIG. 1, solid arrows indicate the flow of solid particles and solid-gas mixtures. Also, dashed arrows indicate the flow of gas and water.

[0016] The gas supply unit 110 supplies gas to the first heat exchanger 130 through a heating chamber 120 described later. The gas supplied by the gas supply unit 110 is, for example, air, carbon dioxide, or combustion exhaust gas. The gas supply unit 110 includes a blower 112 and a gas supply passage 114.

[0017] The blower 112 sucks the gas separated by a solid-gas separator 140 described later and discharges it into the heating chamber 120. The suction side of the blower 112 is connected to a container 202 of a second heat exchanger 200 described later. The discharge side of the blower 112 is connected to the gas supply passage 114.

[0018] The gas supply passage 114 is a flow passage connecting the discharge side of the blower 112 and the heating chamber 120.

[0019] The heating chamber 120 includes a box body 122 and a heater 124. The box body 122 is a hollow container. The upper surface of the box body 122 is composed of a ventable dispersion plate. The upper surface of the box body 122 also functions as the bottom surface of the first heat exchanger 130 described later. The box body 122 is supplied with gas from the gas supply unit 110 (blower 112).

[0020] The heater 124 consumes electric power to heat the gas. The heater 124, for example, converts electric power into heat. The heater 124 is, for example, a resistance heating device (a device that utilizes heat generated from a conductor supplied with electric power) or an arc heating device (a device that utilizes heat generated during arc discharge). The heater 124 is disposed inside the box body 122. The heater 124 heats the gas supplied into the box body 122. Therefore, when the heater 124 operates, the gas supplied from the gas supply unit 110 into the box body 122 is heated by the heater 124 and then supplied into the first heat exchanger 130 through the gas supply port 130a formed in the dispersion plate disposed on the bottom surface of the first heat exchanger 130.

[0021] The first heat exchanger 130 is supplied with gas and solid particles from the bottom surface or the lower part, and exchanges heat between the gas and the solid particles. The solid particles are made of a material having a melting point higher than the required temperature of the heat utilization device 254 described later.

[0022] The solid particles are, for example, silica, alumina, barite sand (baryte, barium sulfate), partially calcined clay, glass beads, recovered petroleum catalyst, etc. The solid particles are preferably one or both of silica and alumina. When the solid particles are silica, the cost required for the solid particles can be reduced. Also, by using desert sand or river sand as the solid particles (silica), it becomes possible to obtain them at low cost and easily. Also, by using alumina, which has a relatively high melting point, as the solid particles, the solid particles can be heated to a high temperature, and a higher energy storage density can be achieved.

[0023] The solid particles are particles with a particle size of 0.01 mm or more and 10 mm or less. There is no limitation on the shape of the solid particles, and they may be spherical or non-spherical.

[0024] In this embodiment, the first heat exchanger 130 is a hollow container. Solid particles are supplied to the first heat exchanger 130 from a high-temperature tank 160 and a low-temperature tank 180, which will be described later. Also, as described above, gas is supplied to the first heat exchanger 130 from the gas supply unit 110 through the heating chamber 120. The flow rate of the gas supplied to the first heat exchanger 130 by the gas supply unit 110 is equal to or higher than the terminal velocity of the solid particles in the first heat exchanger 130. Further, the solid particles are supplied from above the gas supply port 130a formed in the distributor disposed on the bottom surface of the first heat exchanger 130. Therefore, the solid-gas mixture of the solid particles and the gas passes through the first heat exchanger 130 from the lower part to the upper part (from the bottom surface to the top surface). Also, in the first heat exchanger 130, a solid-gas mixture of solid particles and gas is formed, and since the solid particles and the gas are strongly agitated, the solid particles and the gas efficiently contact and exchange heat.

[0025] The solid-gas separator 140 separates the solid-gas mixture discharged from the first heat exchanger 130 into solid and gas. The solid-gas separator 140 is, for example, a cyclone or a filter.

[0026] The switching unit 150 switches the supply destination of the solid particles separated into solid and gas by the solid-gas separator 140 to the high-temperature tank 160 or the low-temperature tank 180. The switching unit 150 includes pipes 152a, 152b and valves 154a, 154b. The pipe 152a connects the solid particle discharge port of the solid-gas separator 140 and the high-temperature tank 160. The valve 154a is provided in the pipe 152a. The pipe 152b connects the solid particle discharge port of the solid-gas separator 140 and the low-temperature tank 180. The valve 154b is provided in the pipe 152b. Note that the valve 154a and the valve 154b are exclusively opened and closed by a control unit 260, which will be described later.

[0027] The high-temperature tank 160 stores the solid particles separated from gas by the solid-gas separator 140. The high-temperature tank 160 is, for example, a hopper.

[0028] The high-temperature particle supply unit 170 supplies the solid particles stored in the high-temperature tank 160 to the first heat exchanger 130. The high-temperature particle supply unit 170 includes, for example, a high-temperature particle supply pipe 172 and a flow rate adjustment mechanism 174. The high-temperature particle supply pipe 172 connects the inside of the high-temperature tank 160 and the inside of the first heat exchanger 130. In the present embodiment, the high-temperature particle supply pipe 172 connects the lower part of the high-temperature tank 160 and the lower part of the first heat exchanger 130. In the present embodiment, the lower part of the high-temperature tank 160 is located above the lower part of the first heat exchanger 130. Therefore, the solid particles stored in the high-temperature tank 160 move to the first heat exchanger 130 by their own weight through the high-temperature particle supply pipe 172.

[0029] The flow rate adjustment mechanism 174 adjusts the flow rate of the solid particles supplied from the high-temperature tank 160 to the first heat exchanger 130. The flow rate adjustment mechanism 174 is, for example, a J-valve type loop seal or an L-valve type loop seal. The flow rate adjustment mechanism 174 is provided on the high-temperature particle supply pipe 172.

[0030] The low-temperature tank 180 stores the solid particles that have been separated from gas by the solid-gas separator 140 and are at a lower temperature than the solid particles stored in the high-temperature tank 160. The solid particles are supplied to the low-temperature tank 180 at a timing different from that of the high-temperature tank 160. The low-temperature tank 180 is, for example, a hopper.

[0031] The low-temperature particle supply unit 190 supplies the solid particles stored in the low-temperature tank 180 to the second heat exchanger 200 described later, and supplies the solid particles from the second heat exchanger 200 to the first heat exchanger 130. The low-temperature particle supply unit 190 includes a first particle supply pipe 192 (low-temperature particle supply pipe), a second particle supply pipe 194 (low-temperature particle supply pipe), and a flow rate adjustment mechanism 196. The first particle supply pipe 192 communicates the inside of the low-temperature tank 180 and the accommodation chamber 202a of the second heat exchanger 200. In the present embodiment, the lower part of the low-temperature tank 180 is located above the accommodation chamber 202a of the second heat exchanger 200. Therefore, the solid particles stored in the low-temperature tank 180 move to the accommodation chamber 202a of the second heat exchanger 200 by their own weight through the first particle supply pipe 192. The second particle supply pipe 194 communicates the inside of the accommodation chamber 202a of the second heat exchanger 200 and the inside of the first heat exchanger 130.

[0032] The flow rate adjustment mechanism 196 is provided in the second particle supply pipe 194. The flow rate adjustment mechanism 196 adjusts the flow rate of the solid particles supplied from the low-temperature tank 180 to the second heat exchanger 200. The flow rate adjustment mechanism 196 is, for example, a screw feeder.

[0033] The second heat exchanger 200 exchanges heat between the solid particles stored in the low-temperature tank 180 and the gas separated by the solid-gas separator 140. The gas passage portion 210 allows the gas separated by the solid-gas separator 140 to pass through the second heat exchanger 200.

[0034] FIG. 2 is a diagram showing an example of the second heat exchanger 200 and the gas passage portion 210 according to the present embodiment. As shown in FIG. 2, the second heat exchanger 200 includes a container 202, a dispersion plate 204, and a partition plate 206.

[0035] The container 202 has, for example, a rectangular tube shape. The dispersion plate 204 is provided inside the container 202. The dispersion plate 204 extends in the horizontal direction and divides the inside of the container 202 into an accommodation chamber 202a and a plenum chamber 202b. A plurality of holes are formed in the dispersion plate 204. The sizes of the plurality of holes are such that solid particles cannot pass through or have difficulty passing through.

[0036] The storage chamber 202a is formed at the upper part of the container 202. The volume of the storage chamber 202a is smaller than that of the cryogenic tank 180. The volume of the storage chamber 202a is, for example, 1 / 10000 of the cryogenic tank 180. The dispersion plate 204 functions as the bottom surface of the storage chamber 202a.

[0037] The bellows chamber 202b is formed below the storage chamber 202a in the container 202.

[0038] In the present embodiment, on one side of the upper surface of the container 202, the first particle supply pipe 192 constituting the cryogenic particle supply unit 190 penetrates. The upper end opening of the first particle supply pipe 192 is connected to the lower part of the cryogenic tank 180. Also, the lower end opening of the first particle supply pipe 192 is disposed in the storage chamber 202a. The lower end opening of the first particle supply pipe 192 is located below the upper end opening of the second particle supply pipe 194 described later. In the present embodiment, the lower end opening of the first particle supply pipe 192 is located in the vicinity of the dispersion plate 204.

[0039] The solid particles stored in the cryogenic tank 180 are supplied to the storage chamber 202a through the first particle supply pipe 192. Therefore, the storage chamber 202a stores solid particles.

[0040] Also, in the present embodiment, the second particle supply pipe 194 constituting the cryogenic particle supply unit 190 connects the storage chamber 202a and the flow rate adjustment mechanism 196 provided at the lower part of the first heat exchanger 130. The upper end of the second particle supply pipe 194 is connected to the vicinity of the upper surface of the fluidized bed in the storage chamber 202a on the other side surface of the container 202. The lower end of the second particle supply pipe 194 is connected to the flow rate adjustment mechanism 196. The flow rate adjustment mechanism 196 is connected above the gas supply port 130a in the first heat exchanger 130.

[0041] The partition plate 206 is provided in the storage chamber 202a in the vicinity of the side surface to which the second particle supply pipe 194 is connected. The partition plate 206 is a plate extending in the vertical direction or substantially the vertical direction. The partition plate 206 is separated from the upper surface of the container 202 and the dispersion plate 204.

[0042] The gas passage part 210 allows the gas separated by the solid-gas separator 140 to pass through the inside of the accommodation chamber 202a of the second heat exchanger 200. The gas passage part 210 includes a first supply pipe 212, a second supply pipe 214, valves 212a and 214a, an exhaust pipe 216, a first steam generation part 220, and a water supply part 230.

[0043] The first supply pipe 212 connects the gas exhaust port of the solid-gas separator 140 and the wind box chamber 202b (for example, the bottom surface of the container 202) of the second heat exchanger 200. A valve 212a is provided in the first supply pipe 212.

[0044] The second supply pipe 214 connects between the solid-gas separator 140 and the valve 212a in the first supply pipe 212 and between the valve 212a and the wind box chamber 202b in the first supply pipe 212. A valve 214a is provided in the second supply pipe 214.

[0045] In this embodiment, the valves 212a and 214a are exclusively opened and closed by the control part 260.

[0046] The exhaust pipe 216 connects the accommodation chamber 202a (for example, the upper surface of the container 202) of the second heat exchanger 200 and the suction side of the blower 112.

[0047] In this embodiment, the second heat exchanger 200 is designed such that the superficial velocity of the gas (fluidization gas) supplied into the accommodation chamber 202a by the gas passage part 210 is equal to or greater than the minimum fluidization velocity Umf and less than the terminal velocity. Thereby, the solid particles supplied from the low-temperature tank 180 are fluidized by the gas supplied from the solid-gas separator 140, and a fluidized bed (bubble fluidized bed) is formed in the accommodation chamber 202a. Further, since the superficial velocity of the gas supplied by the gas passage part 210 is less than the terminal velocity, the solid particles do not scatter from the accommodation chamber 202a.

[0048] As described above, the gas supplied from the solid-gas separator 140 to the container 202 through the first supply pipe 212 forms a fluidized bed of solid particles in the accommodation chamber 202a and is then supplied to the blower 112 through the exhaust pipe 216. Note that the gas supplied to the container 202 through the first supply pipe 212 is heat-exchanged with the solid particles in the accommodation chamber 202a during the passage process in the accommodation chamber 202a.

[0049] The gas after being heat-exchanged with the solid particles is supplied to the blower 112 through the exhaust pipe 216. The blower 112 supplies the gas after being heat-exchanged by the second heat exchanger 200 to the first heat exchanger 130 through the heating chamber 120. Therefore, in this embodiment, the blower 112 circulates the gas in the order of the solid-gas separator 140, the gas passage portion 210, the second heat exchanger 200, the heating chamber 120, and the first heat exchanger 130.

[0050] Also, in this embodiment, the volume of the accommodation chamber 202a of the second heat exchanger 200 is determined such that the temperature of the gas after heat exchange is equal to or lower than the heat-resistant temperature of the blower 112. The volume of the accommodation chamber 202a of the second heat exchanger 200 is determined based on the suction flow rate of the blower 112 and the temperature of the solid particles accommodated in the low-temperature tank 180. For example, the volume of the accommodation chamber 202a of the second heat exchanger 200 is determined such that the temperature of the gas after heat exchange by the solid particles at the highest temperature stored in the low-temperature tank 180 is equal to or lower than the heat-resistant temperature of the blower 112. Thereby, while preventing damage to the blower 112, the gas supplied to the blower 112 can be preheated.

[0051] Also, as described above, a fluidized bed of solid particles is formed in the accommodation chamber 202a. Therefore, when solid particles are supplied from the low-temperature tank 180 through the first particle supply pipe 192, the supplied amount of solid particles is pushed out (overflowed) to the second particle supply pipe 194. Then, the pushed-out solid particles, that is, the solid particles heat-exchanged with the gas supplied by the gas passage portion 210 in the accommodation chamber 202a are supplied to the first heat exchanger 130 through the second particle supply pipe 194 and the flow rate adjustment mechanism 196.

[0052] Note that, as described above, the partition plate 206 is provided in the storage chamber 202a. Therefore, the solid particles supplied from the first particle supply pipe 192 move in the storage chamber 202a and pass below the partition plate 206. As a result, it is possible to avoid a situation where the solid particles move the shortest distance from the opening at the lower end of the first particle supply pipe 192 to the opening at the upper end of the second particle supply pipe 194. Thereby, it becomes possible to efficiently perform heat exchange between the solid particles and the gas.

[0053] The first steam generation unit 220 is provided on the downstream side of the valve 214a in the second supply pipe 214. The first steam generation unit 220 cools the gas by heat-exchanging the gas and water separated by the solid-gas separator 140, and generates steam by heating the water.

[0054] The water supply unit 230 supplies water to the first steam generation unit 220. The water supply unit 230 is, for example, a pump. The water supplied to the first steam generation unit 220 by the water supply unit 230 is supplied to the heat utilization device 232 through the outlet of the first steam generation unit 220. The water is heated to become steam by heat-exchanging with the gas separated by the solid-gas separator 140 during the process of passing through the first steam generation unit 220. Therefore, steam is supplied to the heat utilization device 232.

[0055] The heat utilization device 232 is a device that utilizes the thermal energy of the steam generated by the first steam generation unit 220. The heat utilization device 232 is, for example, a steam turbine generator (boiler), a boiler that provides steam, a furnace (kiln), or an air conditioning device.

[0056] Returning to FIG. 1 for explanation, the second steam generation unit 240 is provided between the valve 154b and the low-temperature tank 180 in the pipe 152b that constitutes the switching unit 150. The second steam generation unit 240 (steam generation unit) generates steam by heat-exchanging the solid particles and water separated by the solid-gas separator 140, cooling the solid particles, and heating the water. The solid particles cooled by the second steam generation unit 240 are supplied to the low-temperature tank 180.

[0057] FIG. 3 is a diagram showing an example of the second water vapor generation unit 240 according to the present embodiment. As shown in FIG. 3, the second water vapor generation unit 240 includes a container 242, a dispersion plate 244a, an exhaust pipe 244b, a fluidization gas supply unit 246, and a heat transfer pipe 248.

[0058] The container 242 is, for example, in a rectangular tube shape. The dispersion plate 244a is provided inside the container 242. The dispersion plate 244a extends in the horizontal direction and divides the inside of the container 242 into a storage chamber 242a and a plenum chamber 242b. A plurality of holes are formed in the dispersion plate 244a. The size of the plurality of holes is such that solid particles cannot pass through or have difficulty passing through. The storage chamber 242a is formed at the upper part of the container 242. The plenum chamber 242b is formed below the storage chamber 242a in the container 242. The dispersion plate 244a functions as the bottom surface of the storage chamber 242a.

[0059] In the present embodiment, the pipe 152b constituting the switching unit 150 is composed of a pipe 156 and a pipe 158. The pipe 156 penetrates the upper surface of the container 242. The upper end opening of the pipe 156 is connected to the lower part of the solid-gas separator 140. Also, the lower end opening of the pipe 156 is disposed in the storage chamber 242a. The lower end opening of the pipe 156 is located below the upper end opening of the pipe 158 described later. In the present embodiment, the lower end opening of the pipe 156 is located in the vicinity of the dispersion plate 244a.

[0060] The solid particles separated by the solid-gas separator 140 are supplied to the storage chamber 242a through the pipe 156. Therefore, the storage chamber 242a stores solid particles.

[0061] The fluidization gas supply unit 246 is, for example, a pump, a blower, or the like. The suction side of the fluidization gas supply unit 246 is connected to a fluidization gas supply source. The discharge side of the fluidization gas supply unit 246 is connected to the plenum chamber 242b. The fluidization gas is, for example, steam, air, carbon dioxide, or combustion exhaust gas. The fluidization gas supply unit 246 supplies the fluidization gas into the plenum chamber 242b such that the superficial velocity of the fluidization gas supplied into the accommodation chamber 242a through the dispersion plate 244a is equal to or higher than the minimum fluidization velocity Umf and lower than the terminal velocity. Thereby, the solid particles supplied from the solid-gas separator 140 are fluidized by the fluidization gas, and a fluidized bed (bubble fluidized bed) is formed in the accommodation chamber 242a. Further, since the superficial velocity of the fluidization gas supplied by the fluidization gas supply unit 246 is lower than the terminal velocity, solid particles do not scatter from the accommodation chamber 242a.

[0062] A part of the heat transfer tube 248 is disposed in the accommodation chamber 242a. A water supply unit 250 is connected to the inlet of the heat transfer tube 248. A heat utilization device 254 is connected to the outlet of the heat transfer tube 248.

[0063] Further, an exhaust pipe 244b is connected to the upper surface of the container 242. The exhaust pipe 244b supplies the fluidization gas to the heat utilization device 252.

[0064] The heat utilization device 252 is a device that utilizes the thermal energy of the fluidization gas exhausted from the second steam generation unit 240. The heat utilization device 252 is, for example, a gas turbine generator, a steam turbine generator (boiler), a boiler that provides steam, a furnace (kiln), or an air conditioning device.

[0065] The water supply unit 250 supplies water to the heat transfer tube 248. The water supply unit 250 is, for example, a pump. The water supplied to the heat transfer tube 248 by the water supply unit 250 is supplied to the heat utilization device 254 through the outlet of the heat transfer tube 248. The water is heated to become steam by exchanging heat with the fluidized bed of the solid particles formed in the accommodation chamber 242a during the passage through the heat transfer tube 248. Therefore, steam is supplied to the heat utilization device 254.

[0066] The heat utilization device 254 is a device that utilizes the thermal energy of the water vapor generated by the second water vapor generation unit 240. The heat utilization device 254 is, for example, a steam turbine generator (boiler), a boiler that provides steam, a furnace (kiln), or an air conditioning device.

[0067] In the present embodiment, the pipe 158 that constitutes the pipe 152b of the switching unit 150 connects the storage chamber 242a and the low-temperature tank 180. The upper end of the pipe 158 is connected to the side surface of the container 242 near the upper surface of the fluidized bed in the storage chamber 242a.

[0068] As described above, a fluidized bed of solid particles is formed in the storage chamber 242a. Therefore, when solid particles are supplied from the solid-gas separator 140 through the pipe 156, the supplied amount of solid particles is pushed out (overflowed) into the pipe 158. Then, the pushed-out solid particles, that is, the solid particles cooled by heat exchange with the water passing through the heat transfer pipe 248, are supplied to the low-temperature tank 180 through the pipe 158. For this reason, the low-temperature tank 180 stores the solid particles after heat exchange by the second water vapor generation unit 240.

[0069] Returning to FIG. 1 for explanation, the control unit 260 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit). The control unit 260 reads out programs, parameters, etc. for operating the CPU from the ROM. The control unit 260 manages and controls the entire energy storage device 100 in cooperation with a RAM as a work area and other electronic circuits. In the present embodiment, the control unit 260 controls the gas supply unit 110 (blower 112), the heater 124, the switching unit 150 (valves 154a, 154b), the flow rate adjustment mechanisms 174, 196, the valves 212a, 214a, the fluidization gas supply unit 246, the water supply units 230, 250.

[0070] In this embodiment, the control unit 260 executes one of a plurality of operation modes. The plurality of operation modes include at least, for example, a heat storage mode and a heat dissipation mode. The heat storage mode is a mode in which, in a system where the energy storage device 100 is provided, surplus power (that is, generated power amount - required power amount > a predetermined value (for example, 0)) occurs, and the surplus power is converted into thermal energy and stored. That is, the heat storage mode is an operation mode in which surplus power is converted into thermal energy and stored. The heat dissipation mode is an operation mode in which, when heat or power is required in a system where the energy storage device 100 is provided, the stored thermal energy is utilized by the heat utilization devices 232, 252, and 254. That is, the heat dissipation mode is an operation mode in which the stored thermal energy is utilized by the heat utilization devices 232, 252, and 254. Note that the generated power amount is the amount of power generated by power generation equipment installed in the system where the energy storage device 100 is provided. Also, the required power amount is the amount of power consumed by consumers in the system where the energy storage device 100 is provided.

[0071] Also, in the initial state, the blower 112, the heater 124, the fluidized gas supply unit 246, the water supply units 230 and 250, and the flow rate adjustment mechanism 196 are stopped, and the valves 154a, 154b, the flow rate adjustment mechanism 174, and the valves 212a and 214a are closed. Also, in the initial state, the solid particles are stored in the low-temperature tank 180. Hereinafter, the processing of the control unit 260 in each of the heat storage mode and the heat dissipation mode will be described.

[0072] [Heat Storage Mode] FIG. 4 is a diagram for explaining the processing of the control unit 260 in the heat storage mode. For ease of understanding, in FIG. 4, components not used in the heat storage mode are omitted.

[0073] The control unit 260 closes the valves 154b, 214a, and the flow rate adjustment mechanism 174. The control unit 260 stops the fluidizing gas supply unit 246, the water supply units 230, 250. Also, as shown in FIG. 4, the control unit 260 supplies power to the blower 112 and the heater 124 to operate the blower 112 and the heater 124. Further, the control unit 260 opens the valves 154a, 212a. The control unit 260 operates the flow rate adjustment mechanism 196.

[0074] Then, surplus power is consumed by the heater 124. The gas supplied to the heating chamber 120 by the blower 112 is heated by the heater 124. The heater 124 heats the gas to a first temperature that is below the melting point of the solid particles and satisfies the required temperature of the heat utilization device 254. For example, the heater 124 heats the gas such that the solid particles heated by the gas at the first temperature reach a second temperature that satisfies the required temperature of the heat utilization device 254 in the first heat exchanger 130. When the solid particles are silica, the gas is heated to 1600°C or lower. Also, the second temperature is lower than the first temperature, but the temperature difference is small. The temperature difference between the second temperature and the first temperature is, for example, about 50°C. The first temperature is, for example, 1600°C, and the second temperature is, for example, 1550°C.

[0075] The high-temperature gas (gas at the first temperature) thus heated is supplied to the first heat exchanger 130.

[0076] On the other hand, solid particles are supplied from the low-temperature tank 180 to the accommodation chamber 202a of the second heat exchanger 200. Also, the gas separated by the solid-gas separator 140 is supplied into the accommodation chamber 202a of the second heat exchanger 200 from the first supply pipe 212 that constitutes the gas passage part 210. Thereby, a fluidized bed of solid particles is formed in the accommodation chamber 202a. Therefore, in the second heat exchanger 200, heat exchange is performed between the gas at the second temperature and the solid particles at a sixth temperature described later. Thereby, the solid particles are heated by the gas, and the gas is cooled by the solid particles.

[0077] After heat exchange in the second heat exchanger 200, the temperature of the solid particles and the gas becomes a third temperature lower than the second temperature. The third temperature is equal to or lower than the heat-resistant temperature of the blower 112. The third temperature is, for example, 550°C.

[0078] In the second heat exchanger 200, the solid particles at the third temperature heated from the sixth temperature by heat exchange with the gas at the second temperature are supplied to the first heat exchanger 130 through the second particle supply pipe 194. Therefore, the second heat exchanger 200 can raise the temperature of the solid particles supplied to the first heat exchanger 130 to a third temperature higher than the sixth temperature. Thereby, the second heat exchanger 200 can preheat the solid particles before being supplied to the first heat exchanger 130 with the heat (waste heat) of the gas separated by the solid-gas separator 140.

[0079] Also, as described above, since the heated high-temperature gas (gas at the first temperature) is supplied to the first heat exchanger 130, in the first heat exchanger 130, the gas at the first temperature and the solid particles at the third temperature are strongly agitated, and heat exchange is performed between the gas and the solid particles. Thereby, the solid particles are further heated by the gas, and the gas is cooled by the solid particles. Note that at the outlet of the first heat exchanger 130, the temperature of the solid particles and the temperature of the gas become substantially equal (become the second temperature).

[0080] Then, the solid-gas separator 140 separates the solid-gas mixture discharged from the first heat exchanger 130 into solid and gas. The separated high-temperature solid particles (solid particles at the second temperature) are supplied to the high-temperature tank 160 through the pipe 152a constituting the switching unit 150. The high-temperature tank 160 stores the solid particles at the second temperature.

[0081] On the other hand, the separated gas at the second temperature is supplied to the second heat exchanger 200 through the first supply pipe 212 constituting the gas passage portion 210. The second heat exchanger 200 performs heat exchange between the gas at the second temperature supplied from the solid-gas separator 140 through the first supply pipe 212 and the solid particles at the sixth temperature supplied from the low-temperature tank 180.

[0082] Thus, in the heat storage mode, the excess power is converted into heat by the heater 124 and first transferred to the gas. Then, heat exchange occurs between the high-temperature gas and the low-temperature solid particles, and the heat is transferred to the solid particles. In this way, the excess power is converted into thermal energy and retained (stored) in the solid particles. Since the heat capacity of the solid particles is larger than that of the gas (air), the heat storage density (J / m 3 ) of the solid particles is higher than that of the gas.

[0083] Note that the control unit 260 adjusts the operating speed of the flow rate adjustment mechanism 196 based on the amount of excess power (hereinafter referred to as "excess power amount"). Specifically, when the power of the excess power amount is converted into thermal energy by the heater 124 and the solid particles are heated with this thermal energy (through the gas), the amount of solid particles at the second temperature is determined. Therefore, the control unit 260 adjusts the operating speed of the flow rate adjustment mechanism 196 so that the determined amount of solid particles is supplied to the first heat exchanger 130.

[0084] Thereby, even when the excess power amount fluctuates (when the excess power amount fluctuates over time), the temperature of the solid particles stored in the high-temperature tank 160 can be constantly maintained at the second temperature. That is, it can cope with the fluctuation of the excess power amount. Therefore, in the heat dissipation mode described later, it is possible to supply steam or fluidized gas at the fourth temperature that satisfies the required temperature to the heat utilization devices 232, 252, 254 without using additional energy (for example, without burning auxiliary fuel).

[0085] [Heat Dissipation Mode] FIG. 5 is a diagram for explaining the processing of the control unit 260 in the heat dissipation mode. For ease of understanding, in FIG. 5, the configurations not used in the heat dissipation mode are omitted.

[0086] The control unit 260 stops the valves 154a, 212a, and the flow rate adjustment mechanism 196. The control unit 260 stops the heater 124. Also, as shown in FIG. 5, the control unit 260 opens the valves 154b, 214a, and opens the flow rate adjustment mechanism 174 to adjust the opening degree. The control unit 260 operates the blower 112, the fluidized gas supply unit 246, the water supply units 230, 250.

[0087] Then, high-temperature solid particles (solid particles at the second temperature) are supplied from the high-temperature tank 160 to the first heat exchanger 130.

[0088] Also, gas is supplied from the blower 112 to the first heat exchanger 130 through the box body 122. As described above, since the heater 124 is stopped, the gas supplied from the blower 112 to the first heat exchanger 130 through the box body 122 is at the fifth temperature described later. Therefore, in the first heat exchanger 130, heat exchange is performed between the low-temperature gas and the high-temperature solid particles. As a result, the gas is heated by the solid particles, and the solid particles are cooled by the gas. Note that the temperatures of the solid particles and the gas discharged from the first heat exchanger 130 are approximately equal and are at the fourth temperature.

[0089] Then, the solid-gas separator 140 separates the solid-gas mixture discharged from the first heat exchanger 130 into solid and gas. The separated high-temperature gas (gas at the fourth temperature) is supplied to the first steam generation unit 220. In the first steam generation unit 220, heat exchange is performed between the water supplied by the water supply unit 230 and the gas at the fourth temperature, the water is heated, and the gas is cooled. As a result, steam at the fifth temperature is generated and supplied to the heat utilization device 232. Also, the gas cooled to the fifth temperature is supplied to the second heat exchanger 200 by the gas passage unit 210. The fifth temperature is lower than the fourth temperature. The fifth temperature is, for example, 150°C.

[0090] In this way, in the heat dissipation mode, heat exchange is performed between the high-temperature gas and the low-temperature water, and heat is transferred to the water. Then, when needed (for example, during a period when power is insufficient), the high-temperature water (water at the fifth temperature) is used (for example, for power generation) in the heat utilization device 232.

[0091] In the heat dissipation mode, since the flow rate adjustment mechanism 196 is stopped, no new solid particles are supplied to the second heat exchanger 200. Therefore, the gas at the fifth temperature supplied to the second heat exchanger 200 by the gas passage portion 210 is directly supplied to the blower 112.

[0092] In addition, the high-temperature solid particles (solid particles at the fourth temperature) separated by the solid-gas separator 140 are supplied to the second water vapor generation unit 240. In the second water vapor generation unit 240, heat exchange is performed between the water supplied by the water supply unit 250 and the solid particles at the fourth temperature, so that the water is heated and the solid particles are cooled. As a result, water vapor at the sixth temperature is generated and supplied to the heat utilization device 254. In addition, heat exchange is performed between the fluidization gas supplied by the fluidization gas supply unit 246 and the solid particles at the fourth temperature, so that the fluidization gas is heated and the solid particles are cooled. As a result, fluidization gas at the sixth temperature is generated and supplied to the heat utilization device 252.

[0093] The control unit 260 adjusts the opening degree of the flow rate adjustment mechanism 174 based on the required temperature and required flow rate of the heat utilization device 254. Specifically, when the water supply unit 250 supplies water to the heat transfer tube 248 of the second water vapor generation unit 240 at the required flow rate of the heat utilization device 254 and heats the water with the solid particles at the fourth temperature supplied from the solid-gas separator 140, the amount of solid particles for heating the water to the sixth temperature is determined. Therefore, the control unit 260 adjusts the opening degree of the flow rate adjustment mechanism 174 so that the determined amount of solid particles is supplied to the second water vapor generation unit 240.

[0094] Thereby, the temperature of the water supplied to the heat utilization device 254 can be made the required temperature of the heat utilization device 254. Therefore, it is possible to stably supply water at the sixth temperature that satisfies the required temperature to the heat utilization device 254 without using additional energy (for example, without burning auxiliary fuel). Even if the required temperature of the heat utilization device 254 (for example, the required power generation amount) varies over time, it is possible to adjust the supply amount of the solid particles to cope with it.

[0095] Further, the solid particles cooled to the sixth temperature are supplied to the low-temperature tank 180 through the pipe 152b that constitutes the switching unit 150. The low-temperature tank 180 stores the solid particles at the sixth temperature. The sixth temperature is lower than the fourth temperature. The sixth temperature may be equal to or different from the fifth temperature.

[0096] Thus, in the heat dissipation mode, heat exchange is performed between the high-temperature solid particles and the low-temperature water, and heat is transferred to the water. Then, when needed (for example, during a period of power shortage), the high-temperature water (water at the sixth temperature) is utilized (for example, used for power generation) in the heat utilization device 254. Also, heat exchange is performed between the high-temperature solid particles and the low-temperature fluidized gas, and heat is transferred to the fluidized gas. Then, when needed (for example, during a period of power shortage), the high-temperature fluidized gas (fluidized gas at the sixth temperature) is utilized (for example, used for power generation) in the heat utilization device 252.

[0097] As described above, the energy storage device 100 according to the present embodiment converts surplus power into thermal energy and stores it in solid particles. Thereby, it becomes possible to store energy at a low cost compared to the prior art of storing surplus power in a secondary battery or the prior art of converting surplus power into hydrogen. Also, compared to the prior art of converting and storing surplus power into hydrogen, when needed (for example, when power is insufficient), the stored energy can be converted into thermal energy or electrical energy at high speed.

[0098] Also, as described above, the energy storage device 100 according to the present embodiment includes the second heat exchanger 200. Thereby, in the heat storage mode, compared to the case of directly supplying the solid particles from the low-temperature tank 180 to the first heat exchanger 130, the temperature of the solid particles supplied to the first heat exchanger 130 can be increased. Therefore, in the heat storage mode, even when the amount of surplus power supplied to the heater 124 is small, it is possible to surely heat the solid particles to the second temperature.

[0099] Also, as described above, in the heat storage mode, the second heat exchanger 200 raises the temperature of the solid particles with the heat of the high-temperature gas separated by the solid-gas separator 140. That is, the energy storage device 100 can preheat the solid particles with the heat (waste heat) of the high-temperature gas that is secondarily generated by storing heat in the solid particles in the heat storage mode. Thereby, the energy storage device 100 can efficiently utilize the waste heat generated in the heat storage mode.

[0100] Also, as described above, the volume of the accommodation chamber 202a of the second heat exchanger 200 is smaller than that of the low-temperature tank 180. Thereby, the blower 112 can be reduced in size as compared with the case where the gas separated by the solid-gas separator 140 is passed through the low-temperature tank 180. Therefore, it is possible to reduce the power consumption of the blower 112.

[0101] Also, as described above, the second heat exchanger 200 exchanges heat between the fluidized bed of solid particles and the heat medium. Thereby, it becomes possible to efficiently exchange heat between the solid particles and the heat medium. Therefore, the second heat exchanger 200 can efficiently heat the solid particles.

[0102] Also, as described above, the energy storage device 100 includes a second steam generation unit 240. Thereby, the energy storage device 100 can generate steam by the second steam generation unit 240 in the heat dissipation mode.

[0103] As described above, the embodiments have been described with reference to the accompanying drawings. Needless to say, the present disclosure is not limited to the above embodiments. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that those also belong to the technical scope of the present disclosure.

[0104] For example, in the above embodiment, a configuration in which gas is supplied from the bottom surface of the first heat exchanger 130 was described as an example. However, the gas may be supplied from below the solid particle supply location in the first heat exchanger 130. For example, the gas may be supplied from the lower part of the first heat exchanger 130. Further, the gas supply unit 110 may supply gas at normal pressure or may supply pressurized gas.

[0105] Also, in the above embodiment, a case where the gas passage portion 210 supplies gas from the bottom surface of the accommodation chamber 202a of the second heat exchanger 200 was described as an example. However, the gas passage portion 210 may supply gas from the lower part of the accommodation chamber 202a of the second heat exchanger 200.

[0106] Also, in the above embodiment, a configuration in which the gas passage portion 210 forms a fluidized bed of solid particles in the accommodation chamber 202a of the second heat exchanger 200 was described as an example. Thereby, in the heat storage mode, the heat medium can be efficiently heated by the heat of the solid particles. However, the configuration of the second heat exchanger 200 is not limited as long as it can exchange heat between the solid particles and the gas. For example, the gas passage portion 210 may form a moving bed of solid particles in the accommodation chamber 202a of the second heat exchanger 200.

[0107] Similarly, in the above embodiment, a configuration in which the second steam generation unit 240 forms a fluidized bed of solid particles was described as an example. Thereby, in the heat dissipation mode, water can be efficiently heated by the heat of the solid particles. However, the configuration of the second steam generation unit 240 is not limited as long as it can exchange heat between the solid particles and the water. For example, the accommodation chamber 242a of the second steam generation unit 240 may form a moving bed of solid particles, for example.

[0108] Also, in the above embodiment, a case where the energy storage device 100 includes the second steam generation unit 240 was described as an example. However, the second steam generation unit 240 is not an essential configuration.

[0109] In addition, in the above embodiment, a period during which power is surplus (generated power amount - required power amount > a predetermined value (for example, 0)) is set as a heat storage mode. However, when it is necessary to convert power into other energy (for example, when it is necessary to consume power to stabilize the power grid), the heat storage mode may also be adopted. Further, it is set as a heat dissipation mode when needed. However, when it is necessary to utilize heat (for example, when it is desired to utilize heat in a cement factory), the heat dissipation mode may also be adopted.

[0110] In addition, a heater may be installed inside the first heat exchanger 130.

[0111] The present disclosure can contribute to, for example, Goal 7 of the Sustainable Development Goals (SDGs), "Ensure access to affordable, reliable, sustainable and modern energy".

Explanation of reference numerals

[0112] 100 Energy storage device 110 Gas supply unit 112 Blower 124 Heater 130 First heat exchanger 130a Gas supply port 140 Solid-gas separator 160 High-temperature tank 172 High-temperature particle supply pipe 180 Low-temperature tank 192 First particle supply pipe (low-temperature particle supply pipe) 194 Second particle supply pipe (low-temperature particle supply pipe) 200 Second heat exchanger 202a Accommodation chamber 210 Gas passage part 240 Second steam generation part (steam generation part) 260 Control unit

Claims

1. A first heat exchanger in which gas is supplied from a gas supply port formed on the bottom surface or lower part, solid particles are supplied from above the gas supply port, and heat exchange is performed between the gas and the solid particles; A gas supply unit including a blower that supplies gas to the first heat exchanger; A heater that heats either one or both of the gas supplied from the gas supply unit to the first heat exchanger and the gas in the first heat exchanger by consuming electric power; A solid-gas separator that separates the solid-gas mixture discharged from the first heat exchanger; A high-temperature tank that stores the solid particles separated by the solid-gas separator; A high-temperature particle supply pipe that communicates the inside of the high-temperature tank with the inside of the first heat exchanger; A low-temperature tank that stores the solid particles separated by the solid-gas separator and having a temperature lower than that of the solid particles stored in the high-temperature tank; A second heat exchanger having a storage chamber with a volume smaller than that of the low-temperature tank and accommodating the solid particles supplied from the low-temperature tank, and performing heat exchange between the solid particles and the gas separated by the solid-gas separator; A gas passage portion that allows the gas separated by the solid-gas separator to pass through the storage chamber of the second heat exchanger; A low-temperature particle supply pipe including a first particle supply pipe that communicates the inside of the low-temperature tank with the storage chamber of the second heat exchanger and a second particle supply pipe that communicates the storage chamber with the inside of the first heat exchanger; And comprising The gas supply unit is an energy storage device that supplies the gas after heat exchange by the second heat exchanger to the first heat exchanger.

2. The energy storage device according to claim 1, wherein the volume of the storage chamber of the second heat exchanger is determined such that the temperature of the gas after heat exchange by the second heat exchanger is equal to or lower than the heat-resistant temperature of the blower of the gas supply unit.

3. The gas passage part forms a fluidized bed of the solid particles in the accommodation chamber by supplying the gas separated by the solid-gas separator from the bottom surface or lower part of the accommodation chamber of the second heat exchanger. The energy storage device according to claim 1 or 2.

4. Further comprising a steam generation part that exchanges heat between the solid particles separated by the solid-gas separator and water to cool the solid particles and heat the water to generate steam. The low-temperature tank stores the solid particles after heat exchange by the steam generation part. The energy storage device according to claim 1 or 2.

5. Comprising the gas supply part and a control part that controls the heater. The control part Executes any one of a plurality of operation modes. The plurality of operation modes include a heat storage mode and a heat dissipation mode. In the heat storage mode Controls the gas supply part to supply the gas to the first heat exchanger, supplies power to the heater to heat the gas, supplies the solid particles stored in the low-temperature tank to the accommodation chamber of the second heat exchanger, supplies solid particles from the accommodation chamber of the second heat exchanger to the first heat exchanger, heats the solid particles with the gas in the first heat exchanger, supplies the solid particles separated by the solid-gas separator to the high-temperature tank, and supplies the gas separated by the solid-gas separator to the accommodation chamber of the second heat exchanger. In the heat dissipation mode Supplies the solid particles from the high-temperature tank to the first heat exchanger, stops the heater, controls the gas supply part to supply the gas to the first heat exchanger, heats the gas with the solid particles in the first heat exchanger, supplies the solid particles separated by the solid-gas separator to the steam generation part, and supplies the solid particles from the steam generation part to the low-temperature tank. The energy storage device according to claim 4.

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