Energy accumulation device

Abstract

To expand a range of a heating temperature of an object to be heated.SOLUTION: An energy accumulation device 100 includes: a high temperature tank 160 for storing solid particles; a low temperature tank 170 for storing solid particles of which temperature is lower than that of the solid particles stored in the high temperature tank 160; a mixer 230 that mixes the solid particles supplied from the high temperature tank 160 and the solid particles supplied from the low temperature tank 170; a second heat exchanger 250 that exchanges heat between the solid particles mixed by the mixer 230 and an object to be heated to heat the object to be heated; a high temperature flow rate adjustment mechanism 164 that adjusts the flow rate of the solid particles to be supplied from the high temperature tank 160 to the mixer 230; and a first low temperature flow rate adjustment mechanism 222 that adjusts the flow rate of the solid particles to be supplied from the low temperature tank 170 to the mixer 230.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 "consumed power amount") do not always match. For this reason, a power surplus may occur where the generated power amount exceeds the consumed power amount, or a power shortage may occur where the generated power amount is less than the consumed 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 store heat in the solid particles, and when a power shortage occurs, the heat stored in the solid particles is converted into electric power. Technologies have been developed (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] By the way, in various plants, heat utilization devices are widely used for heating, drying, sterilizing, cleaning, etc. of objects to be heated. However, the preferred heating temperature of the object to be heated differs for each purpose such as heating, drying, sterilizing, cleaning, etc. For this reason, there is a demand for the development of a technology for expanding the range of heating temperatures of objects to be heated by heat utilization devices using surplus electric power.

[0006] In view of such problems, an object of the present disclosure is to provide an energy storage device capable of expanding the range of heating temperatures of an object to be heated.

Means for Solving the Problems

[0007] To solve the above problems, an energy storage device according to an aspect of the present disclosure includes a first heat exchanger that supplies gas from a gas supply port formed on the bottom surface or lower part, supplies solid particles from above the gas supply port, and exchanges heat between the gas and the solid particles, a gas supply unit that supplies gas to the first heat exchanger, a first 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 low-temperature tank that stores solid particles having a lower temperature than the solid particles separated by the solid-gas separator and stored in the high-temperature tank, a mixer that mixes the solid particles supplied from the high-temperature tank and the solid particles supplied from the low-temperature tank, a second heat exchanger that heats an object to be heated by exchanging heat between the solid particles mixed by the mixer and the object to be heated, a high-temperature particle supply pipe that communicates the outlet of the high-temperature tank and the mixer, a high-temperature flow adjustment mechanism provided in the high-temperature particle supply pipe that adjusts the flow rate of the solid particles supplied from the high-temperature tank to the mixer, a first low-temperature particle supply pipe that communicates the outlet of the low-temperature tank and the mixer, a first low-temperature flow adjustment mechanism provided in the first low-temperature particle supply pipe that adjusts the flow rate of the solid particles supplied from the low-temperature tank to the mixer, a second low-temperature particle supply pipe that communicates the outlet of the low-temperature tank and the first heat exchanger, a second low-temperature flow adjustment mechanism provided in the second low-temperature particle supply pipe that adjusts the flow rate of the solid particles supplied from the low-temperature tank to the first heat exchanger, and a mixed particle supply pipe that communicates the outlet of the second heat exchanger and the first heat exchanger.

[0008] Further, the energy storage device may include a second heater that heats the solid particles in the low-temperature tank by consuming electric power.

[0009] Further, the second heater may heat the solid particles near the outlet of the low-temperature tank.

[0010] Further, the second heater may include a heat pump system, and the heat pump system consumes electric power to compress a heat medium, heat-exchanges the heat medium compressed by the compressor with solid particles in the low-temperature tank to condense the heat medium by cooling the heat medium and heat the solid particles, includes a condenser; a decompression unit that decompresses the heat medium condensed by the condenser; and an evaporator that heat-exchanges the heat medium decompressed by the decompression unit with an external cooling fluid to vaporize the heat medium by heating the heat medium and cool the cooling fluid.

[0011] Also, the volume of the low-temperature tank may be larger than the volume of the high-temperature tank.

[0012] The energy storage device includes a gas supply unit, a first heater, a mixer, a high-temperature flow rate adjustment mechanism, a first low-temperature flow rate adjustment mechanism, and a control unit that controls the second low-temperature flow rate adjustment mechanism. The control unit executes any one of a plurality of operation modes, and the plurality of operation modes include a first heat storage mode and a heat dissipation mode. In the first heat storage mode, the gas supply unit is controlled to supply gas to the first heat exchanger, electric power is supplied to the first heater to heat the gas, the second low-temperature flow rate adjustment mechanism is controlled to supply solid particles from the low-temperature tank to the first heat exchanger, the solid particles are heated by the gas in the first heat exchanger, and the solid particles separated by the solid-gas separator are supplied to the high-temperature tank. In the heat dissipation mode, the high-temperature flow rate adjustment mechanism and the first low-temperature flow rate adjustment mechanism are controlled so that the temperature of the object to be heated heated by the second heat exchanger reaches the required temperature, solid particles are supplied from the high-temperature tank and the low-temperature tank to the mixer, the mixer is operated to mix the solid particles, the solid particles mixed in the mixer are supplied to the second heat exchanger, the solid particles are supplied from the second heat exchanger to the first heat exchanger, heated by the first heater, 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, and the solid particles separated by the solid-gas separator may be supplied to the low-temperature tank.

[0013] The energy storage device includes a second heater that heats the solid particles in the low-temperature tank by consuming power. In addition to the gas supply unit, the first heater, the mixer, the high-temperature flow rate adjustment mechanism, the first low-temperature flow rate adjustment mechanism, and the second low-temperature flow rate adjustment mechanism, the control unit controls the second heater. In the first heat storage mode, the control unit may supply power to the second heater to heat the solid particles stored in the low-temperature tank.

[0014] The plurality of operation modes further includes a second heat storage mode. In the second heat storage mode, the control unit may stop heating by the first heater and supply power to the second heater to heat the solid particles stored in the low-temperature tank.

[0015] The plurality of operation modes further includes a third heat storage mode. In the third heat storage mode, the control unit controls the high-temperature flow rate adjustment mechanism and the first low-temperature flow rate adjustment mechanism so that the temperature of the object to be heated heated by the second heat exchanger reaches the required temperature, supplies solid particles from the high-temperature tank and the low-temperature tank to the mixer, operates the mixer to mix the solid particles, supplies the solid particles mixed in the mixer to the second heat exchanger, and supplies the solid particles from the second heat exchanger to the first heat exchanger.

Advantages of the Invention

[0016] According to the present disclosure, it is possible to expand the range of the heating temperature of the object to be heated.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Figure 9

[0018] 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 facilitating understanding, and do not limit the present disclosure unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant descriptions are omitted. Further, elements not directly related to the present disclosure are not shown.

[0019] [Energy storage device 100] FIG. 1 is a diagram for explaining the energy storage device 100 according to the present embodiment. As shown in FIG. 1, the energy storage device 100 includes a gas supply unit 110, a bellows chamber 130, a first heat exchanger 140, a first heater 142, a solid-gas separator 150, a switching unit 152, a high-temperature tank 160, a high-temperature particle supply pipe 162, a high-temperature flow rate adjustment mechanism 164, a low-temperature tank 170, a second heater 190, a first low-temperature particle supply pipe 220, a first low-temperature flow rate adjustment mechanism 222, a second low-temperature particle supply pipe 224, a mixer 230, a second heat exchanger 250, a mixed particle supply pipe 252, 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.

[0020] The gas supply unit 110 supplies gas to the first heat exchanger 140 via the bellows chamber 130 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, a first gas supply pipe 114, a second gas supply pipe 116, a third gas supply pipe 118, a fourth gas supply pipe 120, a valve 114a, a valve 116a, and a valve 120a.

[0021] The blower 112 sucks gas from the low-temperature tank 170 described later and discharges it into the bellows chamber 130. The discharge side of the blower 112 is connected to the first gas supply pipe 114.

[0022] The first gas supply pipe 114 communicates the discharge side of the blower 112 with the bellows chamber 130. A valve 114a is provided in the first gas supply pipe 114. The valve 114a opens and closes the flow path formed in the first gas supply pipe 114.

[0023] The second gas supply pipe 116 communicates the gas outlet of the solid-gas separator 150 described later with the low-temperature tank 170 described later. A valve 116a is provided in the second gas supply pipe 116. The valve 116a opens and closes the flow path formed in the second gas supply pipe 116.

[0024] The third gas supply pipe 118 communicates the low-temperature tank 170 with the suction side of the blower 112.

[0025] The fourth gas supply pipe 120 communicates the first gas supply pipe 114 with the second gas supply pipe 116. The fourth gas supply pipe 120 communicates between the blower 112 and the valve 114a in the first gas supply pipe 114 and between the solid-gas separator 150 and the valve 116a in the second gas supply pipe 116. A valve 120a is provided in the fourth gas supply pipe 120. The valve 120a opens and closes the flow path formed in the fourth gas supply pipe 120.

[0026] The bellows chamber 130 is a hollow container. The upper surface of the bellows chamber 130 is composed of a ventable dispersion plate 132 (distributor). The upper surface of the bellows chamber 130 also functions as the bottom surface of the first heat exchanger 140 described later. A gas is supplied to the bellows chamber 130 from the gas supply unit 110 (blower 112). One or more gas supply ports 140a are formed in the upper surface (dispersion plate 132) of the bellows chamber 130. The size of the gas supply port 140a is such that solid particles cannot pass through or have difficulty passing through.

[0027] The first heat exchanger 140 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 with a melting point higher than the required temperature of the second heat exchanger 250 described later.

[0028] The solid particles are, for example, silica, alumina, barite sand (baryte, barium sulfate), partially calcined clay, glass beads, recycled petroleum catalysts, etc. The solid particles are preferably either 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.

[0029] 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.

[0030] In this embodiment, the first heat exchanger 140 is a hollow container. Solid particles are supplied to the first heat exchanger 140 from the low-temperature tank 170 and the second heat exchanger 250. Also, as described above, gas is supplied to the first heat exchanger 140 from the gas supply unit 110 through the plenum chamber 130. The flow rate of the gas supplied to the first heat exchanger 140 by the gas supply unit 110 is equal to or greater than the terminal velocity of the solid particles in the first heat exchanger 140. Further, the solid particles are supplied from above the gas supply port 140a formed in the dispersion plate 132 disposed on the bottom surface of the first heat exchanger 140. Therefore, the solid-gas mixture of the solid particles and the gas passes through the first heat exchanger 140 from the lower part to the upper part (from the bottom surface to the upper surface). Also, in the first heat exchanger 140, a solid-gas mixture of solid particles and gas is formed, and the solid particles and the gas are strongly agitated, so that the solid particles and the gas are efficiently brought into contact with each other for heat exchange.

[0031] The first heater 142 consumes electric power to heat the gas. The first heater 142, for example, converts electric power into heat. The first heater 142 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 first heater 142 is disposed in the vicinity of the bottom surface (dispersion plate 132) in the first heat exchanger 140. Therefore, when the first heater 142 operates, the first heater 142 heats the gas supplied into the first heat exchanger 140 through the gas supply port 140a. Also, when the first heater 142 operates, the first heater 142 heats the solid particles supplied to the first heat exchanger 140.

[0032] The solid-gas separator 150 separates the solid-gas mixture discharged from the first heat exchanger 140 into solid and gas. The solid-gas separator 150 is, for example, a cyclone or a filter.

[0033] The switching unit 152 switches the supply destination of the solid particles solid-gas separated by the solid-gas separator 150 to the high-temperature tank 160 or the low-temperature tank 170. The switching unit 152 includes pipes 154a and 154b and valves 156a and 156b. Pipe 154a communicates the solid particle discharge port of the solid-gas separator 150 with the high-temperature tank 160. Valve 156a is provided in pipe 154a. Valve 156a opens and closes the flow path formed in pipe 154a. Pipe 154b communicates the solid particle discharge port of the solid-gas separator 150 with the low-temperature tank 170. Valve 156b is provided in pipe 154b. Valve 156b opens and closes the flow path formed in pipe 154b. Note that valves 156a and 156b are exclusively opened and closed by a control unit 260 described later.

[0034] The high-temperature tank 160 stores the solid particles solid-gas separated by the solid-gas separator 150. The high-temperature tank 160 is, for example, a hopper.

[0035] The high-temperature particle supply pipe 162 communicates the outlet of the high-temperature tank 160 with a mixer 230 described later. A high-temperature flow rate adjustment mechanism 164 is provided in the high-temperature particle supply pipe 162.

[0036] The high-temperature flow rate adjustment mechanism 164 adjusts the flow rate of the solid particles supplied from the high-temperature tank 160 to the mixer 230. In the present embodiment, the high-temperature tank 160 is provided above the mixer 230. Therefore, when the high-temperature particle supply pipe 162 is opened by the high-temperature flow rate adjustment mechanism 164, the solid particles stored in the high-temperature tank 160 are supplied to the mixer 230 by their own weight. The high-temperature flow rate adjustment mechanism 164 is, for example, a J-valve type loop seal or an L-valve type loop seal.

[0037] The low-temperature tank 170 stores the solid particles solid-gas separated by the solid-gas separator 150. The low-temperature tank 170 stores solid particles at a lower temperature than the solid particles stored in the high-temperature tank 160. The volume of the low-temperature tank 170 is, for example, larger than the volume of the high-temperature tank 160. Solid particles are supplied to the low-temperature tank 170 at a different timing from the high-temperature tank 160.

[0038] FIG. 2 is a diagram showing an example of the cryogenic tank 170 according to the present embodiment. As shown in FIG. 2, in the present embodiment, the cryogenic tank 170 includes, for example, a container 172, a dispersion plate 174, a solid-gas separator 176, a first partition plate 178, and a second partition plate 180.

[0039] The container 172 has, for example, a rectangular tube shape. The dispersion plate 174 is provided inside the container 172. The dispersion plate 174 extends in the horizontal direction and divides the inside of the container 172 into a storage chamber 172a and a plenum chamber 172b. A plurality of holes are formed in the dispersion plate 174. The size of the plurality of holes is such that solid particles cannot pass through or have difficulty passing through. The storage chamber 172a is formed at the upper part of the container 172. The plenum chamber 172b (fluidization gas supply section) is formed below the storage chamber 172a in the container 172. The dispersion plate 174 functions as the bottom surface of the storage chamber 172a.

[0040] In the present embodiment, the pipe 154b connected to the solid outlet of the solid-gas separator 150 is connected to the upper surface of the container 172. The pipe 154b is connected, for example, in the vicinity of one side surface 172c on the upper surface of the container 172. Also, in the present embodiment, the solid-gas separator 150 is provided above the container 172. Therefore, the solid particles separated by the solid-gas separator 150 are supplied to the container 172 (storage chamber 172a) by their own weight through the pipe 154b. For this reason, the storage chamber 172a contains solid particles. Note that, in the present embodiment, the volume of the storage chamber 172a is larger than the volume of the high-temperature tank 160, for example.

[0041] The solid-gas separator 176 separates the solid-gas mixture discharged from the headspace of the storage chamber 172a into solid and gas. The solid-gas separator 176 is, for example, a cyclone or a filter. The solid outlet of the solid-gas separator 176 communicates with the upper surface of the container 172. The suction side of the blower 112 is connected to the gas outlet of the solid-gas separator 176 through the third gas supply pipe 118.

[0042] Also, in the present embodiment, the second gas supply pipe 116 connected to the gas outlet of the solid-gas separator 150 is connected to the plenum chamber 172b.

[0043] Therefore, when the blower 112 operates, the gas separated by the solid-gas separator 150 is supplied to the plenum chamber 172b. Then, the gas supplied to the plenum chamber 172b is supplied into the accommodation chamber 172a through the dispersion plate 174. Note that the blower 112 supplies the gas into the plenum chamber 172b such that the superficial gas velocity of the gas supplied to the accommodation chamber 172a is equal to or greater than the minimum fluidization velocity Umf and less than the terminal velocity. As a result, the solid particles supplied from the solid-gas separator 150 are fluidized by the gas, and a fluidized bed (bubble fluidized bed) of the solid particles is formed in the accommodation chamber 172a. Further, since the superficial gas velocity of the gas supplied by the blower 112 is less than the terminal velocity, almost no solid particles scatter from the accommodation chamber 172a.

[0044] The first partition plate 178 is a plate provided in the accommodation chamber 172a. The first partition plate 178 stands upright in the vertical direction or a substantially vertical direction from the dispersion plate 174. The first partition plate 178 is provided, for example, in the vicinity of the other side surface 172d of the container 172. The upper end of the first partition plate 178 is spaced apart from the upper surface of the container 172. The upper end of the first partition plate 178 is located, for example, below the upper surface of the fluidized bed.

[0045] Further, one or a plurality of openings 178a are provided in the first partition plate 178. The openings 178a are sized such that solid particles can pass therethrough. The openings 178a are formed, for example, in the vicinity of the lower end of the first partition plate 178.

[0046] The second partition plate 180 is provided in the accommodation chamber 172a between the first partition plate 178 and the side surface 172c (in the left-right direction in FIG. 2). The second partition plate 180 is provided in the vicinity of the first partition plate 178. The second partition plate 180 is a plate extending in the vertical direction or a substantially vertical direction. The second partition plate 180 is spaced apart from the upper surface of the container 172 and the dispersion plate 174. The upper end of the second partition plate 180 is located above the upper end of the first partition plate 178. The upper end of the second partition plate 180 is located, for example, above the upper surface of the fluidized bed.

[0047] In addition, an outlet 182 for solid particles (the outlet 182 of the low-temperature tank 170) is formed between the first partition plate 178 and the side surface 172d in the dispersion plate 174. A low-temperature particle discharge pipe 184 communicates with the outlet 182. A valve 184a is provided in the low-temperature particle discharge pipe 184. The valve 184a opens and closes a flow path formed in the low-temperature particle discharge pipe 184.

[0048] The second heater 190 heats the solid particles in the low-temperature tank 170 by consuming electric power. The second heater 190 may heat the solid particles near the outlet 182 in the accommodation chamber 172a. The second heater 190 heats, for example, the solid particles between the first partition plate 178 and the side surface 172d. In the present embodiment, the second heater 190 includes a plurality of heat pump systems 192A to 192C. The heating location by the heat pump system 192A is near the outlet 182 in the accommodation chamber 172a. The heating location by the heat pump system 192B is above the heating location by the heat pump system 192A. The heating location by the heat pump system 192C is above the heating location by the heat pump system 192B.

[0049] FIG. 3 is a diagram showing an example of the heat pump system 192A of the second heater 190 according to the present embodiment. As shown in FIG. 3, the heat pump system 192A according to the present embodiment includes a circulation path 200, a compressor 202, a condenser 204, a decompression unit 206, and an evaporator 208. Note that the heat pump systems 192B and 192C are only different from the heat pump system 192A in the installation position of the condenser 204, and the other configurations are substantially the same as those of the heat pump system 192A. For this reason, here, each configuration of the heat pump system 192A will be described, and the descriptions of the heat pump systems 192B and 192C will be omitted.

[0050] The circulation path 200 is a flow path through which a heat medium (refrigerant) circulates. The compressor 202, the condenser 204, the decompression unit 206, and the evaporator 208 are provided in the circulation path 200.

[0051] The compressor 202 consumes power to compress the heat medium. The compressor 202 adiabatically compresses, for example, the heat medium in a gaseous state. By being compressed by the compressor 202, the heat medium is heated.

[0052] The condenser 204 is provided on the downstream side of the compressor 202 in the circulation path 200. Also, in the present embodiment, the condensers 204 of the heat pump system 192A, the heat pump system 192B, and the heat pump system 192C are all provided between the first partition plate 178 and the side surface 172d in the accommodation chamber 172a of the low-temperature tank 170. Note that the condenser 204 of the heat pump system 192A is provided near the outlet 182 in the accommodation chamber 172a. The condenser 204 of the heat pump system 192B is provided above the condenser 204 of the heat pump system 192A. The condenser 204 of the heat pump system 192C is provided above the condenser 204 of the heat pump system 192B.

[0053] The condenser 204 cools the heat medium by causing heat exchange between the heat medium compressed by the compressor 202 and the solid particles in the accommodation chamber 172a of the low-temperature tank 170, thereby condensing the heat medium and heating the solid particles.

[0054] The decompression unit 206 decompresses the heat medium in a gas-liquid mixed state condensed by the condenser 204. The decompression unit 206, for example, expands the heat medium under reduced pressure. As a result, the heat medium is further cooled and becomes a liquid state. The decompression unit 206 is, for example, an expansion valve.

[0055] The evaporator 208 causes heat exchange between the heat medium decompressed by the decompression unit 206 and an external cooling fluid, thereby vaporizing the heat medium by heating the heat medium and cooling the cooling fluid. The cooling fluid is, for example, outside air, river water, or seawater.

[0056] Returning to FIG. 2 for explanation, the first low-temperature particle supply pipe 220 communicates the outlet 182 of the low-temperature tank 170 with the mixer 230. In the present embodiment, the first low-temperature particle supply pipe 220 is connected to the outlet 182 of the low-temperature tank 170 through the low-temperature particle discharge pipe 184. A first low-temperature flow rate adjustment mechanism 222 is provided in the first low-temperature particle supply pipe 220.

[0057] The first low-temperature flow rate adjustment mechanism 222 adjusts the flow rate of the solid particles supplied from the low-temperature tank 170 to the mixer 230. In the present embodiment, the low-temperature tank 170 is provided above the mixer 230. Therefore, when the low-temperature particle discharge pipe 184 is opened by the valve 184a and the first low-temperature particle supply pipe 220 is opened by the first low-temperature flow rate adjustment mechanism 222, the solid particles stored in the low-temperature tank 170 are supplied to the mixer 230 by their own weight. The first low-temperature flow rate adjustment mechanism 222 is, for example, a J-valve type loop seal, an L-valve type loop seal, or a rotary valve.

[0058] The second low-temperature particle supply pipe 224 communicates the outlet 182 of the low-temperature tank 170 with the first heat exchanger 140. In the present embodiment, the second low-temperature particle supply pipe 224 is connected to the outlet 182 of the low-temperature tank 170 through the low-temperature particle discharge pipe 184, similar to the first low-temperature particle supply pipe 220. A second low-temperature flow rate adjustment mechanism 224a is provided in the second low-temperature particle supply pipe 224. The second low-temperature flow rate adjustment mechanism 224a adjusts the flow rate of the solid particles supplied from the low-temperature tank 170 to the first heat exchanger 140. The second low-temperature flow rate adjustment mechanism 224a is, for example, a J-valve type loop seal, an L-valve type loop seal, or a rotary valve.

[0059] In the present embodiment, the outlet 182 of the low-temperature tank 170 is provided above the inlet of the solid particles provided in the first heat exchanger 140. Therefore, when the second low-temperature particle supply pipe 224 is opened by the second low-temperature flow rate adjustment mechanism 224a, the solid particles stored in the low-temperature tank 170 are supplied to the first heat exchanger 140 by their own weight.

[0060] The mixer 230 mixes the solid particles supplied from the high-temperature tank 160 and the solid particles supplied from the low-temperature tank 170.

[0061] Figure 4 is a diagram showing an example of the mixer 230 according to the present embodiment. As shown in Figure 4, the mixer 230 according to the present embodiment includes a container 232, a dispersion plate 234, a solid-gas separator 236, and a blower 238.

[0062] The container 232 is, for example, in the shape of a rectangular tube. The dispersion plate 234 is provided inside the container 232. The dispersion plate 234 extends in the horizontal direction and divides the inside of the container 232 into a storage chamber 232a and a plenum chamber 232b. A plurality of holes are formed in the dispersion plate 234. The size of the plurality of holes is such that solid particles cannot pass through or have difficulty passing through. The storage chamber 232a is formed at the upper part of the container 232. The plenum chamber 232b is formed below the storage chamber 232a in the container 232. The dispersion plate 234 functions as the bottom surface of the storage chamber 232a.

[0063] In the present embodiment, the high-temperature particle supply pipe 162 communicated with the outlet of the high-temperature tank 160 and the first low-temperature particle supply pipe 220 communicated with the outlet 182 of the low-temperature tank 170 are connected to the upper surface of the container 232. Also, in the present embodiment, the high-temperature tank 160 is provided above the container 232. Therefore, the solid particles stored in the high-temperature tank 160 are supplied to the container 232 (storage chamber 232a) by their own weight through the high-temperature particle supply pipe 162. Similarly, in the present embodiment, the low-temperature tank 170 is provided above the container 232. Therefore, the solid particles stored in the low-temperature tank 170 are supplied to the container 232 (storage chamber 232a) by their own weight through the low-temperature particle discharge pipe 184 and the first low-temperature particle supply pipe 220.

[0064] The solid-gas separator 236 separates the solid-gas mixture discharged from the headspace of the storage chamber 232a into solid and gas. The solid-gas separator 236 is, for example, a cyclone or a filter. The solid outlet of the solid-gas separator 236 communicates with the upper surface of the container 232. The suction side of the blower 238 is connected to the gas outlet of the solid-gas separator 236 through the first fluidization gas circulation pipe 236a.

[0065] The blower 238 sucks the fluidization gas from the accommodation chamber 232a, supplies it to the plenum chamber 232b, and circulates the fluidization gas in the accommodation chamber 232a. The fluidization gas is, for example, air, carbon dioxide, or combustion exhaust gas.

[0066] The suction side of the blower 238 is connected to the gas outlet of the solid-gas separator 236 through the first fluidization gas circulation pipe 236a. The discharge side of the blower 238 is connected to the plenum chamber 232b through the second fluidization gas circulation pipe 238a.

[0067] Therefore, when the blower 238 operates, the fluidization gas is supplied to the plenum chamber 232b. Then, the fluidization gas supplied to the plenum chamber 232b is supplied into the accommodation chamber 232a through the dispersion plate 234. Note that the blower 238 supplies the fluidization gas into the plenum chamber 232b such that the superficial velocity of the fluidization gas supplied to the accommodation chamber 232a is equal to or higher than the minimum fluidization velocity Umf and lower than the terminal velocity. Thereby, the solid particles supplied from the high-temperature tank 160 and the low-temperature tank 170 are fluidized by the fluidization gas, and a fluidized bed (bubble fluidized bed) of the solid particles is formed in the accommodation chamber 232a. Thus, the solid particles supplied from the high-temperature tank 160 and the solid particles supplied from the low-temperature tank 170 in the accommodation chamber 232a are uniformly mixed. Note that since the superficial velocity of the fluidization gas supplied by the blower 238 is lower than the terminal velocity, solid particles hardly scatter from the accommodation chamber 232a.

[0068] The solid particles mixed by the mixer 230 are discharged to the second heat exchanger 250 through the mixed particle discharge pipe 240 connecting the dispersion plate 234 and the second heat exchanger 250. A valve 240a is provided in the mixed particle discharge pipe 240. The valve 240a opens and closes the flow path formed in the mixed particle discharge pipe 240.

[0069] In the present embodiment, the mixer 230 (accommodation chamber 232a) is provided above the second heat exchanger 250. Therefore, the solid particles mixed in the mixer 230 are discharged to the second heat exchanger 250 by their own weight through the mixed particle discharge pipe 240.

[0070] Returning to FIG. 1 for description, the second heat exchanger 250 heats the object to be heated by exchanging heat between the solid particles mixed by the mixer 230 and the object to be heated. The second heat exchanger 250 is, for example, a steam generator, a dryer, a fluid heater, or a powder heater. When the second heat exchanger 250 is a steam generator, the object to be heated is water. When the second heat exchanger 250 is a dryer, the object to be heated is a water-containing solid such as lignite. When the second heat exchanger 250 is a fluid heater, the object to be heated is a fluid. When the second heat exchanger 250 is a powder heater, the object to be heated is a powder.

[0071] The mixed particle supply pipe 252 communicates the outlet of the second heat exchanger 250 with the first heat exchanger 140. A valve 252a is provided in the mixed particle supply pipe 252. The valve 252a opens and closes the flow path formed in the mixed particle supply pipe 252.

[0072] In the present embodiment, the outlet of the second heat exchanger 250 is provided above the inlet of the solid particles provided in the first heat exchanger 140. Therefore, when the mixed particle supply pipe 252 is opened by the valve 252a, the solid particles stored in the second heat exchanger 250 are supplied to the first heat exchanger 140 by their own weight.

[0073] 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 cooperates with a RAM as a work area and other electronic circuits to manage and control the entire energy storage device 100. In the present embodiment, the control unit 260 controls the gas supply unit 110 (blower 112, valves 114a, 116a, 120a), the switching unit 152 (valves 156a, 156b), the high-temperature flow rate adjustment mechanism 164, the valve 184a, the first low-temperature flow rate adjustment mechanism 222, the second low-temperature flow rate adjustment mechanism 224a, the valve 240a, the valve 252a, the first heater 142, the second heater 190 (compressor 202), and the mixer 230 (blower 238).

[0074] In this embodiment, the control unit 260 executes one of a plurality of operation modes. The plurality of operation modes includes, for example, at least 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, during a period when power surplus (that is, generated power amount - consumed power amount > a predetermined value (for example, 0)) occurs, the surplus power is converted into thermal energy for heat storage or utilization. The heat dissipation mode is an operation mode in which, in a system where the energy storage device 100 is provided, the stored thermal energy is utilized by the second heat exchanger 250. Note that the generated power amount is the power amount generated by power generation equipment installed in the system where the energy storage device 100 is provided. Also, the consumed power amount is the power amount consumed by consumers in the system where the energy storage device 100 is provided.

[0075] Also, the heat storage mode according to this embodiment includes a first heat storage mode, a second heat storage mode, and a third heat storage mode. The first heat storage mode is an operation mode that is executed when heat utilization is not required in the second heater 190 and the high-temperature tank 160 is not full. The second heat storage mode is an operation mode that is executed when heat utilization is not required in the second heater 190 and the high-temperature tank 160 is full. The third heat storage mode is an operation mode that is executed when heat utilization is required in the second heater 190. Table 1 below shows the conditions under which the first heat storage mode, the second heat storage mode, the third heat storage mode, and the heat dissipation mode are executed.

[0076]

Table 1

[0077] Also, in the initial state, the blower 112, the first heater 142, the second heater 190 (compressor 202), and the mixer 230 (blower 238) are stopped, and the valves 114a, 116a, 120a, 156a, 156b, the high-temperature flow rate adjustment mechanism 164, the valve 184a, the first low-temperature flow rate adjustment mechanism 222, the second low-temperature flow rate adjustment mechanism 224a, the valve 240a, and the valve 252a are closed. Also, in the initial state, the solid particles are stored in the low-temperature tank 170. Hereinafter, the processing of the control unit 260 in each of the first heat storage mode, the second heat storage mode, the third heat storage mode, and the heat dissipation mode will be described.

[0078] [First Heat Storage Mode] FIG. 5 is a diagram for explaining the processing of the control unit 260 in the first heat storage mode. For ease of understanding, in FIG. 5, the configurations not used in the first heat storage mode are omitted.

[0079] The control unit 260 closes the valves 120a, 156b, the high-temperature flow rate adjustment mechanism 164, the first low-temperature flow rate adjustment mechanism 222, the valve 240a, and the valve 252a. The control unit 260 stops the mixer 230 (blower 238). Also, as shown in FIG. 5, the control unit 260 supplies power to the blower 112, the first heater 142, and the second heater 190 (compressor 202) to operate them. Further, the control unit 260 opens the valves 114a, 116a, 156a, and 184a. The control unit 260 opens the second low-temperature flow rate adjustment mechanism 224a and adjusts the opening degree.

[0080] Then, the gas supplied to the bellows chamber 130 by the blower 112 is supplied into the first heat exchanger 140 through the gas supply port 140a. Also, surplus power is consumed by the first heater 142, and the gas supplied into the first heat exchanger 140 is heated by the first heater 142. The first heater 142 heats the gas to a first temperature below the heat-resistant temperature of the solid particles. When the solid particles are silica, the heat-resistant temperature of the solid particles is, for example, 1600°C. For example, the first heater 142 heats the gas to the first temperature such that the solid particles heated by the gas reach a second temperature. 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 second temperature is, for example, 500°C or higher and 1550°C or lower, and preferably 800°C.

[0081] Also, by sucking gas from the low-temperature tank 170 by the blower 112, gas at the second temperature is supplied from the solid-gas separator 150 to the low-temperature tank 170 through the second gas supply pipe 116. Thereby, the solid particles in the low-temperature tank 170 are heated by the gas at the second temperature and reach a third temperature. The third temperature is lower than the second temperature. The third temperature is, for example, 60°C or higher and 120°C or lower, and preferably 80°C. Also, a fluidized bed of solid particles is formed in the low-temperature tank 170 (accommodation chamber 172a) by the gas supplied from the solid-gas separator 150 to the low-temperature tank 170.

[0082] The solid particles accommodated in the low-temperature tank 170 are further heated to a fourth temperature by the second heater 190. Therefore, the solid particles discharged from the low-temperature tank 170 through the low-temperature particle discharge pipe 184 are at the fourth temperature. The fourth temperature is higher than the third temperature. The fourth temperature is, for example, 100°C or higher and 180°C or lower, and preferably 150°C.

[0083] Then, the solid particles at the fourth temperature discharged from the low-temperature tank 170 through the low-temperature particle discharge pipe 184 are supplied to the first heat exchanger 140 through the second low-temperature particle supply pipe 224.

[0084] As described above, since the gas is heated to the first temperature by the first heater 142 in the first heat exchanger 140, in the first heat exchanger 140, the high-temperature gas (gas at the first temperature) and the low-temperature solid particles (solid particles at the fourth temperature) are strongly stirred, and heat exchange is performed between the high-temperature gas and the low-temperature solid particles. As a result, the solid particles are heated by the gas, and the gas is cooled by the solid particles. Note that at the outlet of the first heat exchanger 140, the temperature of the solid particles and the temperature of the gas become substantially equal (become the second temperature).

[0085] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the first heat exchanger 140 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 154a. The high-temperature tank 160 stores the high-temperature solid particles.

[0086] On the other hand, the separated gas at the second temperature is supplied to the low-temperature tank 170 as described above.

[0087] In this way, in the first heat storage mode, the surplus power is converted into heat by the first heater 142 and first transferred to the gas. Then, heat exchange is performed between the high-temperature gas and the low-temperature solid particles, and the heat is transferred to the solid particles. Thus, the surplus power is converted into thermal energy and held (heat stored) in the solid particles. Note that 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.

[0088] Note that the control unit 260 adjusts the opening degree of the second low-temperature flow rate adjustment mechanism 224a based on the amount of surplus power (hereinafter referred to as "surplus power amount"). Specifically, when the power of the surplus power amount is converted into thermal energy by the first heater 142 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 opening degree of the second low-temperature flow rate adjustment mechanism 224a so that the determined amount of solid particles is supplied to the first heat exchanger 140.

[0089] Accordingly, even when the amount of surplus power varies (when the amount of surplus power varies 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 respond to the variation in the amount of surplus power. Therefore, in the heat dissipation mode described later, it is possible to supply the second heat exchanger 250 with solid particles at the fifth temperature that can heat the object to be heated to the required temperature without using additional energy (for example, without burning auxiliary fuel).

[0090] Also, in the first heat storage mode, the surplus power can be used to operate the second heater 190 (compressor 202). Thereby, in the first heat storage mode, the solid particles in the low-temperature tank 170 can be heated. The second heater 190 includes a heat pump system 192A, a heat pump system 192B, and a heat pump system 192C. Thereby, the second heater 190 can generate, in the condenser 204, a heat quantity that is COP (Coefficient of Performance) times the electric power of 1 unit input to the compressor 202. Therefore, the second heater 190 can efficiently heat the solid particles in the low-temperature tank 170.

[0091] During the execution of the first heat storage mode, the solid particles stored in the low-temperature tank 170 move to the high-temperature tank 160 through the first heat exchanger 140 and the solid-gas separator 150. For this reason, as the execution time of the first heat storage mode elapses, the amount of solid particles stored in the low-temperature tank 170 gradually decreases. That is, the bed height of the fluidized bed in the storage chamber 172a of the low-temperature tank 170 gradually decreases.

[0092] Therefore, the control unit 260 switches the operations of the heat pump system 192A, the heat pump system 192B, and the heat pump system 192C that constitute the second heater 190 in accordance with the bed height of the fluidized bed in the storage chamber 172a of the low-temperature tank 170.

[0093] For example, the control unit 260 operates the heat pump system 192A, the heat pump system 192B, and the heat pump system 192C until the first hour elapses after starting the execution of the first heat storage mode. Then, the control unit 260 stops the heat pump system 192C when the first hour elapses. Further, after the first hour elapses, when the second hour elapses, the control unit 260 stops the heat pump system 192B. Thereby, the control unit 260 can efficiently heat the solid particles in the storage chamber 172a of the low-temperature tank 170 while operating the heat pump system 192A, the heat pump system 192B, and the heat pump system 192C without waste. Note that the first hour is the time when the bed height of the fluidized bed in the storage chamber 172a of the low-temperature tank 170 is equal to or higher than the condenser 204 of the heat pump system 192B and less than the condenser 204 of the heat pump system 192C. The second hour is the time when the bed height of the fluidized bed in the storage chamber 172a of the low-temperature tank 170 is equal to or higher than the condenser 204 of the heat pump system 192A and less than the condenser 204 of the heat pump system 192B.

[0094] [Second Heat Storage Mode] As described above, the second heat storage mode is an operation mode that is executed when the high-temperature tank 160 is full. Therefore, in the second heat storage mode, the solid particles do not move between devices.

[0095] FIG. 6 is a diagram for explaining the processing of the control unit 260 in the second heat storage mode. For ease of understanding, in FIG. 6, the configurations not used in the second heat storage mode are omitted.

[0096] The control unit 260 closes the valve 114a, valve 156a, valve 156b, high-temperature flow rate adjustment mechanism 164, valve 184a, first low-temperature flow rate adjustment mechanism 222, second low-temperature flow rate adjustment mechanism 224a, valve 240a, and valve 252a. The control unit 260 stops the first heater 142 and the mixer 230 (blower 238). Also, as shown in FIG. 6, the control unit 260 supplies power to the blower 112 and the second heater 190 (compressor 202) to operate them. Further, the control unit 260 opens the valve 116a and the valve 120a.

[0097] Then, the gas will circulate through the low-temperature tank 170 by the blower 112. Also, surplus power is consumed by the second heater 190, and the solid particles accommodated in the low-temperature tank 170 (accommodation chamber 172a) are heated to the fourth temperature by the second heater 190. Further, a fluidized bed of solid particles is formed in the low-temperature tank 170 (accommodation chamber 172a) by the gas circulating through the low-temperature tank 170.

[0098] In addition, in the second heat storage mode, only the heat pump system 192A among the second heaters 190 is operated. The condenser 204 of the heat pump system 192A is provided at a position below the layer height of the fluidized bed of solid particles formed in the low-temperature tank 170 when the high-temperature tank 160 is full.

[0099] In the second heat storage mode, the second heater 190 (compressor 202) can be operated using surplus power. Thereby, heat can be stored in the solid particles in the low-temperature tank 170 in the second heat storage mode.

[0100] [Third Heat Storage Mode] As described above, the third heat storage mode is an operation mode executed when heat utilization is required in the second heater 190. FIG. 7 is a first diagram for explaining the processing of the control unit 260 in the third heat storage mode. FIG. 8 is a second diagram for explaining the processing of the control unit 260 in the third heat storage mode. For ease of understanding, in FIGS. 7 and 8, the configurations not used in the third heat storage mode are omitted.

[0101] The control unit 260 closes the valve 120a and the second low-temperature flow rate adjustment mechanism 224a. Then, as shown in FIGS. 7 and 8, the control unit 260 supplies power to the blower 112, the mixer 230 (blower 238), and the second heater 190 (compressor 202) to operate them. Also, as shown in FIGS. 7 and 8, the control unit 260 opens the valves 114a, 116a, 184a, 240a, and 252a, and opens and adjusts the opening degrees of the high-temperature flow rate adjustment mechanism 164 and the first low-temperature flow rate adjustment mechanism 222.

[0102] Then, the high-temperature (approximately the second temperature) solid particles accommodated in the high-temperature tank 160 are supplied to the mixer 230 through the high-temperature particle supply pipe 162. Also, the solid particles accommodated in the low-temperature tank 170 are heated to the fourth temperature by the second heater 190 and discharged from the low-temperature tank 170 to the mixer 230 through the low-temperature particle discharge pipe 184.

[0103] And in the mixer 230, the solid particles supplied from the high-temperature tank 160 and the solid particles supplied from the low-temperature tank 170 are mixed and supplied to the second heat exchanger 250 through the mixed particle discharge pipe 240. Note that the control unit 260 adjusts the opening degrees of the high-temperature flow rate adjustment mechanism 164 and the first low-temperature flow rate adjustment mechanism 222 so that the temperature of the solid particles after being mixed in the mixer 230 becomes the fifth temperature. The fifth temperature is the temperature of the solid particles required to heat the object to be heated to the required temperature in the second heat exchanger 250. The fifth temperature is higher than the required temperature, but the temperature difference is small. The temperature difference between the fifth temperature and the required temperature is, for example, about 50°C. The required temperature is, for example, 120°C or higher and 500°C or lower, and preferably 130°C.

[0104] In the second heat exchanger 250, heat exchange occurs between the solid particles and the object to be heated, the solid particles are cooled, and the object to be heated is heated to the required temperature.

[0105] And the solid particles cooled to the required temperature by heat exchange with the object to be heated in the second heat exchanger 250 are supplied to the first heat exchanger 140 through the mixed particle supply pipe 252.

[0106] Here, when the surplus power amount is equal to or greater than the total power consumption of the first heater 142 and the second heater 190, as shown in FIG. 7, the control unit 260 operates the first heater 142, opens the valve 156a, and closes the valve 156b. Then, since the gas is heated to the first temperature in the first heat exchanger 140 by the first heater 142, in the first heat exchanger 140, the high-temperature (first temperature) gas and the low-temperature (required temperature) solid particles are strongly stirred, and heat exchange is performed between the high-temperature gas and the low-temperature solid particles. Thereby, the solid particles are heated by the gas, and the gas is cooled by the solid particles. Note that at the outlet of the first heat exchanger 140, the temperature of the solid particles and the temperature of the gas become substantially equal (the second temperature).

[0107] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the first heat exchanger 140 into solid and gas. The solid-gas separated high-temperature solid particles (solid particles at the second temperature) are supplied to the high-temperature tank 160 through the pipe 154a. The high-temperature tank 160 stores the high-temperature solid particles. When the high-temperature tank 160 is full, the solid-gas separated high-temperature solid particles are supplied to the low-temperature tank 170 through the pipe 154b. That is, the solid-gas separated high-temperature solid particles are supplied to the high-temperature tank 160 until the high-temperature tank 160 is full. When the high-temperature tank 160 is almost full (specifically, just before being full), the valve 156a is closed, the valve 156b is opened, and the particles are supplied to the low-temperature tank 170.

[0108] The solid-gas separated gas at the second temperature is supplied to the low-temperature tank 170. The solid particles in the low-temperature tank 170 are heated by the gas at the second temperature and become the third temperature. Further, a fluidized bed of solid particles is formed in the low-temperature tank 170 (accommodation chamber 172a) by the gas supplied from the solid-gas separator 150 to the low-temperature tank 170.

[0109] On the one hand, when the surplus power is less than the total power consumption of the first heater 142 and the second heater 190, as shown in FIG. 8, the control unit 260 does not operate (stops) the first heater 142, opens the valve 156b, and closes the valve 156a. Then, in the first heat exchanger 140, the gas at the fourth temperature and the solid particles at the required temperature are strongly agitated. As a result, heat exchange occurs between the gas and the solid particles, and at the outlet of the first heat exchanger 140, the temperature of the solid particles and the temperature of the gas become substantially equal.

[0110] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the first heat exchanger 140 into solid and gas. The solid particles separated into solid and gas are supplied to the low-temperature tank 170 through the pipe 154b.

[0111] The gas separated into solid and gas is supplied to the low-temperature tank 170. Further, a fluidized bed of solid particles is formed in the low-temperature tank 170 (accommodation chamber 172a) by the gas supplied from the solid-gas separator 150 to the low-temperature tank 170.

[0112] In this way, in the third heat storage mode, the control unit 260 can adjust only the opening degree of the high-temperature flow rate adjustment mechanism 164 and the opening degree of the first low-temperature flow rate adjustment mechanism 222 to make the temperature of the solid particles for heating the object to be heated not less than the temperature of the solid particles stored in the low-temperature tank 170 and not more than the temperature of the solid particles stored in the high-temperature tank 160. Therefore, in the third heat storage mode, it is possible to expand the range of the heating temperature of the object to be heated as compared with the case where the object to be heated is heated only by the solid particles stored in the high-temperature tank 160 or only by the solid particles stored in the low-temperature tank 170.

[0113] [Heat dissipation mode] FIG. 9 is a diagram for explaining the processing of the control unit 260 in the heat dissipation mode. For ease of understanding, in FIG. 9, the configurations not used in the heat dissipation mode are omitted.

[0114] The control unit 260 closes the valve 120a, valve 156a, and the second low-temperature flow rate adjustment mechanism 224a. The control unit 260 stops the first heater 142 and the second heater 190 (compressor 202). Also, as shown in FIG. 9, the control unit 260 supplies power to the blower 112 and the mixer 230 (blower 238) to operate them. Further, the control unit 260 opens the valves 114a, 116a, 156b, 184a, 240a, and 252a. The control unit 260 opens the high-temperature flow rate adjustment mechanism 164 and the first low-temperature flow rate adjustment mechanism 222 and adjusts the opening degree.

[0115] Then, the high-temperature (approximately the second temperature) solid particles accommodated in the high-temperature tank 160 are supplied to the mixer 230 through the high-temperature particle supply pipe 162. Also, the low-temperature (approximately the third temperature) solid particles accommodated in the low-temperature tank 170 are discharged from the low-temperature tank 170 to the mixer 230 through the low-temperature particle discharge pipe 184.

[0116] And in the mixer 230, the solid particles supplied from the high-temperature tank 160 and the solid particles supplied from the low-temperature tank 170 are mixed and supplied to the second heat exchanger 250 through the mixed particle discharge pipe 240. Note that the control unit 260 adjusts the opening degrees of the high-temperature flow rate adjustment mechanism 164 and the first low-temperature flow rate adjustment mechanism 222 so that the temperature of the solid particles after being mixed in the mixer 230 becomes the fifth temperature.

[0117] In the second heat exchanger 250, heat exchange occurs between the solid particles and the object to be heated, the solid particles are cooled, and the object to be heated is heated to the required temperature.

[0118] And due to heat exchange with the object to be heated in the second heat exchanger 250, the solid particles cooled to the required temperature are supplied to the first heat exchanger 140 through the mixed particle supply pipe 252.

[0119] Also, the gas supplied to the bellows chamber 130 by the blower 112 is supplied into the first heat exchanger 140 through the gas supply port 140a. As described above, since the first heater 142 is stopped, the gas supplied to the first heat exchanger 140 is at a sixth temperature lower than the fourth temperature. Therefore, in the first heat exchanger 140, heat exchange is performed between the low-temperature gas and the high-temperature (required 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 140 are approximately equal and are at a seventh temperature. The seventh temperature is higher than the sixth temperature and lower than the required temperature.

[0120] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the first heat exchanger 140 into solid and gas. The solid particles at the seventh temperature after solid-gas separation are supplied to the low-temperature tank 170 through the pipe 154b. The low-temperature tank 170 stores the solid particles at the seventh temperature.

[0121] On the other hand, the gas at the seventh temperature after solid-gas separation is supplied to the low-temperature tank 170 as described above. Also, a fluidized bed of solid particles is formed in the low-temperature tank 170 (accommodation chamber 172a) by the gas supplied from the solid-gas separator 150 to the low-temperature tank 170.

[0122] In this way, in the heat dissipation mode, even during a period when power is insufficient, the control unit 260 can adjust only the opening degree of the high-temperature flow rate adjustment mechanism 164 and the opening degree of the first low-temperature flow rate adjustment mechanism 222 to make the temperature of the solid particles for heating the object to be heated not less than the temperature of the solid particles stored in the low-temperature tank 170 and not more than the temperature of the solid particles stored in the high-temperature tank 160.

[0123] In addition, in the heat dissipation mode, it is possible to stably supply solid particles at a fifth temperature that satisfies the required temperature to the second heat exchanger 250 without using additional energy (for example, without burning auxiliary fuel). Therefore, even if the required temperature of the second heat exchanger 250 varies over time, it is possible to correspond to the required temperature of the second heat exchanger 250 by simply adjusting the opening degree of the high-temperature flow rate adjustment mechanism 164 and the opening degree of the first low-temperature flow rate adjustment mechanism 222.

[0124] Furthermore, in the heat dissipation mode, the solid particles stored in the high-temperature tank 160 and the solid particles stored in the low-temperature tank 170 can be mixed and supplied to the second heat exchanger 250. Therefore, it is possible to expand the range of the heating temperature of the object to be heated as compared with the case where the object to be heated is heated only by the solid particles stored in the high-temperature tank 160 or only by the solid particles stored in the low-temperature tank 170.

[0125] As described above, the energy storage device 100 according to the present embodiment converts surplus electric power into thermal energy and stores it in solid particles. Thereby, it becomes possible to store energy at a low cost as compared with the conventional technology of storing surplus electric power in a secondary battery or the conventional technology of converting surplus electric power into hydrogen. Also, as compared with the conventional technology of converting and storing surplus electric power into hydrogen, when it is needed (for example, when the electric power is insufficient), the stored energy can be converted into thermal energy or electric energy at high speed.

[0126] Also, as described above, the energy storage device 100 according to the present embodiment includes a high-temperature tank 160, a high-temperature flow rate adjustment mechanism 164, a low-temperature tank 170, a first low-temperature flow rate adjustment mechanism 222, a mixer 230, and a second heat exchanger 250. Thereby, the energy storage device 100 according to the present embodiment can set the temperature of the solid particles for heating the object to be heated to be equal to or higher than the temperature of the solid particles stored in the low-temperature tank 170 and equal to or lower than the temperature of the solid particles stored in the high-temperature tank 160 only by adjusting the opening degree of the high-temperature flow rate adjustment mechanism 164 and the opening degree of the first low-temperature flow rate adjustment mechanism 222. Therefore, the energy storage device 100 according to the present embodiment can expand the range of the heating temperature of the object to be heated as compared with the case where the object to be heated is heated only by the solid particles stored in the high-temperature tank 160 or only by the solid particles stored in the low-temperature tank 170.

[0127] Also, as described above, the energy storage device 100 according to the present embodiment includes a second heater 190. Thereby, the second heater 190 according to the present embodiment can store heat in the solid particles in the low-temperature tank 170.

[0128] Also, as described above, the second heater 190 according to the present embodiment heats the solid particles near the outlet 182 of the low-temperature tank 170. Thereby, the second heater 190 according to the present embodiment can efficiently heat the solid particles supplied to the first heat exchanger 140 or the mixer 230 through the outlet 182 of the low-temperature tank 170.

[0129] Also, as described above, the second heater 190 according to the present embodiment includes a heat pump system 192A. Thereby, the second heater 190 according to the present embodiment can generate heat in the condenser 204 in an amount that is COP times the amount of electric power input to the compressor 202 per unit of electric power input to the compressor 202. Therefore, the second heater 190 according to the present embodiment can efficiently heat the solid particles in the low-temperature tank 170.

[0130] Also, as described above, in this embodiment, the volume of the low-temperature tank 170 is larger than the volume of the high-temperature tank 160. Thereby, the energy storage device 100 according to this embodiment can expand the lower limit value of the range of the heating temperature of the object to be heated.

[0131] Also, as described above, the low-temperature tank 170 according to this embodiment includes the first partition plate 178. Thereby, the second heater 190 according to this embodiment can more efficiently heat the solid particles supplied to the first heat exchanger 140 or the mixer 230 through the outlet 182 of the low-temperature tank 170.

[0132] Also, as described above, the low-temperature tank 170 according to this embodiment includes the second partition plate 180. Thereby, the low-temperature tank 170 according to this embodiment can suppress the movement of the solid particles heated by the second heater 190 toward the side surface 172c. Therefore, the second heater 190 according to this embodiment can more efficiently heat the solid particles supplied to the first heat exchanger 140 or the mixer 230 through the outlet 182 of the low-temperature tank 170.

[0133] 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 they also belong to the technical scope of the present disclosure.

[0134] For example, in the above embodiment, the configuration in which the gas supply unit 110 includes the blower 112 has been described as an example. However, the gas supply unit 110 is not limited to the configuration as long as it can supply gas to the first heat exchanger 140. For example, instead of the blower 112, the gas supply unit 110 may include a compressed gas source (for example, a compressed air source) or a pump.

[0135] Also, in the above embodiment, the case where the first heater 142 is provided in the first heat exchanger 140 has been described as an example. However, the first heater 142 may be provided in the air box chamber 130.

[0136] In addition, in the above embodiment, the configuration in which gas is supplied from the bottom surface of the first heat exchanger 140 has been described as an example. However, the gas may be supplied from below the solid particle supply location in the first heat exchanger 140. For example, the gas may be supplied from the lower part of the first heat exchanger 140. Further, the gas supply unit 110 may supply gas at normal pressure or pressurized gas.

[0137] In addition, in the above embodiment, the case where the mixer 230 is a fluidized bed device that forms a fluidized bed of solid particles has been described as an example. However, the mixer 230 is not limited to the configuration as long as it can mix the solid particles supplied from the high-temperature tank 160 and the solid particles supplied from the low-temperature tank 170. The mixer 230 may be, for example, a screw mixer.

[0138] In addition, in the above embodiment, the case where the second heater 190 includes the heat pump systems 192A to 192C has been described as an example. However, the second heater 190 only needs to include at least one heat pump system 192A.

[0139] In addition, the second heater 190 is not limited to the configuration as long as it can heat the solid particles in the low-temperature tank 170 by consuming electric power. The second heater 190 may be, for example, a resistance heating device or an arc heating device, similar to the first heater 142.

[0140] In addition, in the above embodiment, the case where the energy storage device 100 includes the second heater 190 has been described as an example. However, the second heater 190 is not an essential configuration.

[0141] In addition, in the above embodiment, the configuration in which the low-temperature tank 170 forms a fluidized bed of solid particles has been described as an example. However, the low-temperature tank 170 is not limited to the configuration as long as it can store solid particles. The low-temperature tank 170 may form, for example, a moving bed of solid particles.

[0142] Also, in the above embodiment, the case where the volume of the low-temperature tank 170 is larger than the volume of the high-temperature tank 160 was taken as an example. However, the volume of the low-temperature tank 170 may be equal to or less than the volume of the high-temperature tank 160.

[0143] Also, in the above embodiment, the control unit 260 was described for the case of executing the heat storage mode during a period when power is surplus (generated power amount - consumed power amount > predetermined value (for example, 0)). However, the control unit 260 may execute the heat storage mode when it is necessary to convert power into other energy (for example, when it is necessary to consume power to stabilize the power grid).

[0144] Also, in the first heat storage mode of the above embodiment, the case of operating the second heater 190 was taken as an example. However, in the first heat storage mode, at least the first heater 142 may be operated, and the second heater 190 may be stopped.

[0145] Also, either one or both of the second heat storage mode and the third heat storage mode may be omitted.

[0146] 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".

Description of Reference Numerals

[0147] 100 Energy Storage Device 110 Gas Supply Unit 140 First Heat Exchanger 140a Gas Supply Port 142 First Heater 150 Solid-Gas Separator 160 High-Temperature Tank 162 High-Temperature Particle Supply Pipe 164 High-Temperature Flow Rate Adjusting Mechanism 170 Low-Temperature Tank 182 Outlet 190 Second Heater 192A Heat Pump System 192B Heat Pump System 192C Heat Pump System 202 Compressor 204 Condenser 206 Pressure Reduction Section 208 Evaporator 220 First Low Temperature Particle Supply Pipe 222 First Low Temperature Flow Rate Adjusting Mechanism 224 Second Low Temperature Particle Supply Pipe 224a Second Low Temperature Flow Rate Adjusting Mechanism 230 Mixer 250 Second Heat Exchanger 252 Mixed Particle Supply Pipe 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 that supplies gas to the first heat exchanger; A first 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 low-temperature tank that stores the solid particles separated by the solid-gas separator and having a lower temperature than the solid particles stored in the high-temperature tank; A mixer that mixes the solid particles supplied from the high-temperature tank and the solid particles supplied from the low-temperature tank; A second heat exchanger that heats an object to be heated by performing heat exchange between the solid particles mixed by the mixer and the object to be heated; A high-temperature particle supply pipe that communicates the outlet of the high-temperature tank and the mixer; A high-temperature flow rate adjustment mechanism provided in the high-temperature particle supply pipe for adjusting the flow rate of the solid particles supplied from the high-temperature tank to the mixer; A first low-temperature particle supply pipe that communicates the outlet of the low-temperature tank and the mixer; A first low-temperature flow rate adjustment mechanism provided in the first low-temperature particle supply pipe for adjusting the flow rate of the solid particles supplied from the low-temperature tank to the mixer; A second low-temperature particle supply pipe that communicates the outlet of the low-temperature tank and the first heat exchanger; A second low-temperature flow rate adjustment mechanism provided in the second low-temperature particle supply pipe for adjusting the flow rate of the solid particles supplied from the low-temperature tank to the first heat exchanger; A mixed particle supply pipe that communicates the outlet of the second heat exchanger and the first heat exchanger; An energy storage device comprising the above.

2. The energy storage device according to claim 1, further comprising a second heater that heats the solid particles in the low-temperature tank by consuming electric power.

3. The energy storage device according to claim 2, wherein the second heater heats the solid particles near the outlet of the low-temperature tank.

4. The second heater includes a heat pump system, The heat pump system includes A compressor that consumes electric power to compress a heat medium, A condenser that cools the heat medium by causing heat exchange between the heat medium compressed by the compressor and the solid particles in the low-temperature tank, thereby condensing the heat medium and heating the solid particles; A decompression unit that decompresses the heat medium condensed by the condenser; An evaporator that causes heat exchange between the heat medium decompressed by the decompression unit and an external cooling fluid, thereby vaporizing the heat medium and cooling the cooling fluid; The energy storage device according to claim 2 or 3, comprising the above.

5. The energy storage device according to claim 1 or 2, wherein the volume of the low-temperature tank is larger than the volume of the high-temperature tank.

6. A control unit that controls the gas supply unit, the first heater, the mixer, the high-temperature flow rate adjustment mechanism, the first low-temperature flow rate adjustment mechanism, and the second low-temperature flow rate adjustment mechanism; The control unit: Executes any one of a plurality of operation modes; The plurality of operation modes include a first heat storage mode and a heat dissipation mode; In the first heat storage mode: Control the gas supply unit to supply gas to the first heat exchanger, supply power to the first heater to heat the gas, control the second low-temperature flow rate adjustment mechanism to supply the solid particles from the low-temperature tank to the first heat exchanger, heat the solid particles with the gas in the first heat exchanger, and supply the solid particles separated by the solid-gas separator to the high-temperature tank; In the heat dissipation mode: Control the high-temperature flow rate adjustment mechanism and the first low-temperature flow rate adjustment mechanism so that the temperature of the object to be heated heated by the second heat exchanger reaches the required temperature, supply solid particles from the high-temperature tank and the low-temperature tank to the mixer, operate the mixer to mix the solid particles, supply the solid particles mixed in the mixer to the second heat exchanger, supply solid particles from the second heat exchanger to the first heat exchanger, stop heating by the first heater, control the gas supply unit to supply gas to the first heat exchanger, heat the gas with the solid particles in the first heat exchanger, and supply the solid particles separated by the solid-gas separator to the low-temperature tank. The energy storage device according to claim 1.

7. A second heater that heats the solid particles in the low-temperature tank by consuming electric power; In addition to the gas supply unit, the first heater, the mixer, the high-temperature flow rate adjustment mechanism, the first low-temperature flow rate adjustment mechanism, and the second low-temperature flow rate adjustment mechanism, the control unit controls the second heater. The energy storage device according to claim 6, wherein in the first heat storage mode, the control unit supplies power to the second heater to heat the solid particles stored in the low-temperature tank.

8. The plurality of operation modes further includes a second heat storage mode. The energy storage device according to claim 7, wherein in the second heat storage mode, the control unit stops heating by the first heater, supplies power to the second heater, and heats the solid particles stored in the low-temperature tank.

9. The plurality of operation modes further includes a third heat storage mode. The energy storage device according to claim 6 or 7, wherein in the third heat storage mode, the control unit controls the high-temperature flow rate adjustment mechanism and the first low-temperature flow rate adjustment mechanism so that the temperature of the object to be heated heated by the second heat exchanger reaches a required temperature, supplies solid particles from the high-temperature tank and the low-temperature tank to the mixer, operates the mixer to mix the solid particles, supplies the solid particles mixed in the mixer to the second heat exchanger, and supplies solid particles from the second heat exchanger to the first heat exchanger.

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