Energy accumulation device

Abstract

To efficiently generate steam.SOLUTION: An energy accumulation device 100 includes: a heat exchanger 140 that exchanges heat between gas and solid particles; a gas supply part 110 that supplies gas to the heat exchanger; a heater 142 that heats the gas to be supplied from the gas supply part to the heat exchanger by consuming electric power; a solid-gas separator 150 that performs solid-gas separation of a solid-gas mixture discharged from the heat exchanger; a high temperature tank 160 that stores the solid particles separated by the solid-gas separator; a high temperature particle supply part 162 that supplies the solid particles stored in the high temperature tank to the heat exchanger; a low temperature tank 200 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 first steam generation part 210 that generates steam by using heat of the solid particles stored in the low temperature tank; and a low temperature particle supply part 202 that supplies the solid particles from the first steam generation part to the heat exchanger.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to energy storage devices. [Background technology]

[0002] The amount of electricity generated (hereinafter referred to as "generated electricity") does not necessarily match the amount of electricity consumed (hereinafter referred to as "demanded electricity"). This can result in a power surplus where the amount of generated electricity exceeds the amount of demanded electricity, or a power shortage where the amount of generated electricity falls short of the amount of demanded electricity. In particular, with power generation using renewable energy sources such as wind power and solar power, it is difficult to adjust the amount of generated electricity, so there is a lot of surplus and shortage of electricity.

[0003] Therefore, a technology has been developed in which, when a power surplus occurs, the surplus power is consumed to heat solid particles, accumulating heat in the solid particles, and, when a power shortage occurs, the heat accumulated in the solid particles is converted into electricity (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2019 / 097932 Summary of the Invention [Problem to be solved by the invention]

[0005] Meanwhile, in various plants, water steam is widely used for heating, drying, sterilizing, cleaning, etc. of objects. Therefore, in the technology of Patent Document 1, there is a demand for development of a technology for efficiently generating water steam by utilizing surplus electricity.

[0006] In view of the above problems, the present disclosure has an object to provide an energy storage device capable of efficiently generating water vapor. [Means for solving the problem]

[0007] In order to solve the above problems, an energy storage device according to one embodiment of the present disclosure includes a heat exchanger that receives gas from a gas supply port formed on a bottom surface or a lower portion, receives 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 heat exchanger, a heater that consumes power to heat either or both of the gas supplied from the gas supply unit to the heat exchanger and the gas in the heat exchanger, a solid-gas separator that separates a solid-gas mixture discharged from the heat exchanger into solid and gas, a high-temperature tank that stores the solid particles separated by the solid-gas separator, a high-temperature particle supply unit that supplies the solid particles stored in the high-temperature tank to the 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 first water vapor generation unit that generates water vapor by utilizing heat possessed by the solid particles stored in the low-temperature tank, and a low-temperature particle supply unit that supplies the solid particles from the first water vapor generation unit to the heat exchanger.

[0008] The first water vapor generating unit may include a heat pump system, which may include a compressor that consumes electricity to compress a heat medium, a condenser that exchanges heat between the heat medium compressed by the compressor and water to condense the heat medium by cooling the heat medium, and generates water vapor by heating the water, a pressure reduction unit that reduces the pressure of the heat medium condensed by the condenser, and an evaporator that exchanges heat between the heat medium reduced in pressure by the pressure reduction unit and solid particles supplied from a low-temperature tank, vaporizes the heat medium by heating the heat medium, and cools the solid particles.

[0009] The high-temperature particle supplying unit may further include a second steam generating unit that receives solid particles from the high-temperature tank, exchanges heat between the solid particles and water to cool the solid particles, and generates steam by heating the water, and a flow rate adjusting mechanism that adjusts the flow rate of the solid particles supplied from the high-temperature tank to the second steam generating unit, and the high-temperature particle supplying unit may supply the solid particles cooled by the second steam generating unit to the heat exchanger.

[0010] The control unit controls the gas supply unit, the heater, the flow rate adjustment mechanism, the low-temperature particle supply unit, and the compressor. The control unit executes one of a plurality of operation modes, the plurality of operation modes including a heat storage mode and a heat dissipation mode. In the heat storage mode, the control unit controls the gas supply unit to supply gas to the heat exchanger, supplies power to the heater to heat the gas, and controls the low-temperature particle supply unit to supply solid particles from the low-temperature tank to the heat exchanger through the first steam generation unit, heats the solid particles with the gas in the heat exchanger, and supplies the solid particles separated by the solid-gas separator to the high-temperature tank. and supplying power to the compressor to operate the heat pump system. In the heat dissipation mode, the flow rate adjustment mechanism is controlled to supply solid particles from the high temperature tank to the second steam generation unit, the solid particles are supplied from the second steam generation unit to the heat exchanger through the high temperature particle supply unit, the heater is stopped, and the gas supply unit is controlled to supply gas to the heat exchanger, the gas is heated by the solid particles in the heat exchanger, and the solid particles separated by the solid-gas separator are supplied to the low temperature tank, so that the difference between the temperature of the solid particles supplied to the evaporator and the temperature of the water vapor generated in the condenser is not more than a predetermined value.

[0011] The evaporator may also include a storage section that stores the solid particles supplied from the low-temperature tank, a circulation path that is provided in the storage section and through which the heat transfer medium depressurized by the depressurization section passes, and a fluidizing gas supply section that supplies a fluidizing gas from a bottom surface or a lower portion of the storage section to form a fluidized bed of the solid particles in the storage section.

[0012] The first steam generating unit may include a container that contains the solid particles supplied from the low-temperature tank, and a heat transfer tube that is provided in the container and through which water passes.

[0013] The container may further include a fluidizing gas supply section for supplying a fluidizing gas from the bottom surface or lower portion of the container to form a fluidized bed of the solid particles within the container.

[0014] The low-temperature tank may further include a third steam generator that performs heat exchange between the solid particles separated by the solid-gas separator and water to cool the solid particles and heat the water to generate steam, and the low-temperature tank may store the solid particles after the heat exchange by the third steam generator.

[0015] The system may further include a control unit that controls the gas supply unit, the heater, the high-temperature particle supply unit, and the low-temperature particle supply unit, and the control unit executes any one of a plurality of operation modes, the plurality of operation modes including a heat storage mode and a heat dissipation mode, in which in the heat storage mode, the gas supply unit is controlled to supply gas to the heat exchanger, power is supplied to the heater to heat the gas, the low-temperature particle supply unit is controlled to supply solid particles from the first steam generation unit to the heat exchanger, the solid particles are heated by the gas in the heat exchanger, and the solid particles separated by the solid-gas separator are supplied to the high-temperature tank, and in the heat dissipation mode, the high-temperature particle supply unit is controlled to supply solid particles from the high-temperature tank to the heat exchanger, the heater is stopped, and the gas supply unit is controlled to supply gas to the heat exchanger, the gas is heated by the solid particles in the heat exchanger, the solid particles separated by the solid-gas separator are supplied to the third steam generation unit, and the solid particles are supplied from the third steam generation unit to the low-temperature tank. Effect of the Invention

[0016] According to the present disclosure, it is possible to efficiently generate water vapor. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram illustrating an energy storage device according to a first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of a second water vapor generating unit according to the first embodiment. [Diagram 3] FIG. 3 is a diagram illustrating an example of a first water vapor generating unit according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating the process of the control unit in the heat storage mode. [Diagram 5] FIG. 5 is a diagram illustrating the process of the control unit in the heat dissipation mode. [Figure 6] FIG. 6 is a diagram illustrating an energy storage device according to the second embodiment. [Figure 7] FIG. 7 is a diagram illustrating the first water vapor generating unit according to the second embodiment. [Figure 8] FIG. 8 is a diagram illustrating the process of the control unit in the heat storage mode. [Figure 9] FIG. 9 is a diagram illustrating the process of the control unit in the heat dissipation mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the 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 ease of understanding, and do not limit the present disclosure unless otherwise specified. In this specification and the drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanation. In addition, elements not directly related to the present disclosure are not illustrated.

[0019] [First embodiment: energy storage device 100] FIG. 1 is a diagram illustrating an energy storage device 100 according to a first embodiment. As shown in FIG. 1, the energy storage device 100 includes a gas supply unit 110, a preheater 120, an air box chamber 130, a heat exchanger 140, a heater 142, a solid-gas separator 150, a switching unit 152, a high-temperature tank 160, a high-temperature particle supply unit 162, a flow rate adjustment mechanism 168, a second steam generation unit 170, a water supply unit 180, a heat utilization device 182, a low-temperature tank 200, a low-temperature particle supply unit 202, a flow rate adjustment mechanism 208, a first steam generation unit 210, a gas delivery unit 220, a heat utilization device 230, and a control unit 240. In FIG. 1, solid arrows indicate the flow of solid particles and a solid-gas mixture. Also, dashed arrows indicate the flow of gas and water.

[0020] The gas supply unit 110 supplies gas to the heat exchanger 140 via an air box 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 and a gas supply path 114.

[0021] The blower 112 sucks in gas and discharges it into the air box chamber 130. The suction side of the blower 112 is connected to a gas supply source. The discharge side of the blower 112 is connected to a gas supply path 114.

[0022] The gas supply passage 114 is a passage that connects the discharge side of the blower 112 and the air box chamber 130 .

[0023] The preheater 120 preheats the gas passing through the gas supply passage 114. In this embodiment, the preheater 120 is a heat exchanger that exchanges heat between the high-temperature gas separated by the solid-gas separator 150 (described later) and the gas passing through the gas supply passage 114. In other words, the preheater 120 preheats the gas with the heat of the high-temperature gas separated by the solid-gas separator 150.

[0024] The wind box chamber 130 is a hollow container. The upper surface of the wind box chamber 130 is made of a ventilation dispersion plate. The upper surface of the wind box chamber 130 also functions as the bottom surface of a heat exchanger 140, which will be described later. Gas is supplied to the wind box chamber 130 from a gas supply unit 110 (blower 112). A gas supply port 140a is formed in the upper surface (dispersion plate) of the wind box chamber 130.

[0025] The heater 142 consumes power to heat the gas. The heater 142 converts power into heat, for example. The heater 142 is, for example, a resistance heating device (a device that uses heat generated from a conductor to which power is supplied) or an arc heating device (a device that uses heat generated during arc discharge). The heater 142 is disposed near the bottom surface (dispersion plate) of the heat exchanger 140, which will be described later. Therefore, when the heater 142 operates, the heater 142 heats the gas supplied into the heat exchanger 140 through the gas supply port 140a.

[0026] Gas and solid particles are supplied to the heat exchanger 140 from the bottom or lower portion, and heat is exchanged 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 heat utilization device 182 described later.

[0027] The solid particles are, for example, silica, alumina, barite sand (barium sulfate), partially calcined clay, glass spheres, recovered 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. In addition, by using desert sand or river sand as the solid particles (silica), it becomes possible to obtain the solid particles at low cost and easily. In addition, by using alumina, which has a relatively high melting point, the solid particles can be heated to a high temperature, and a higher energy storage density can be achieved.

[0028] The solid particles have 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 or may not be spherical.

[0029] In this embodiment, the heat exchanger 140 is a hollow vessel. Solid particles are supplied to the heat exchanger 140 from the high temperature tank 160 and the low temperature tank 200 described later. As described above, gas is supplied to the heat exchanger 140 from the gas supply unit 110 through the wind box chamber 130. The flow velocity of the gas supplied to the heat exchanger 140 by the gas supply unit 110 is equal to or greater than the terminal velocity of the solid particles in the heat exchanger 140. The solid particles are supplied from above through a gas supply port 140a formed in a distributor disposed on the bottom surface of the heat exchanger 140. Therefore, the solid-gas mixture of the solid particles and the gas passes through the heat exchanger 140 from the bottom to the top (from the bottom surface to the top surface). In addition, a solid-gas mixture of the solid particles and the gas is formed in the heat exchanger 140, and the solid particles and the gas are strongly stirred, so that the solid particles and the gas come into contact with each other efficiently and exchange heat.

[0030] The solid-gas separator 150 separates the solid-gas mixture discharged from the heat exchanger 140 into solid and gas. The solid-gas separator 150 is, for example, a cyclone or a filter.

[0031] The switching unit 152 switches the supply destination of the solid particles separated by the solid-gas separator 150 between the high temperature tank 160 and the low temperature tank 200. The switching unit 152 includes pipes 154a, 154b and valves 156a, 156b. The pipe 154a connects the solid particle outlet of the solid-gas separator 150 to the high temperature tank 160. The valve 156a is provided in the pipe 154a. The pipe 154b connects the solid particle outlet of the solid-gas separator 150 to the low temperature tank 200. The valve 156b is provided in the pipe 154b. The valves 156a and 156b are opened and closed exclusively by the control unit 240 described later.

[0032] The high-temperature tank 160 stores the solid particles separated from the solid-gas by the solid-gas separator 150. The high-temperature tank 160 is, for example, a hopper.

[0033] The high-temperature particle supplying unit 162 supplies the solid particles stored in the high-temperature tank 160 to a second steam generating unit 170 (described later), and then supplies the solid particles to the heat exchanger 140. The high-temperature particle supplying unit 162 includes pipes 164 and 166. The pipe 164 connects a lower part of the high-temperature tank 160 and the second steam generating unit 170. The pipe 166 connects a lower part of the second steam generating unit 170 and the heat exchanger 140.

[0034] The flow rate adjustment mechanism 168 is provided in the pipe 164. The flow rate adjustment mechanism 168 adjusts the flow rate of the solid particles supplied from the high temperature tank 160 to the second steam generation section 170. The flow rate adjustment mechanism 168 is, for example, a J-valve type loop seal or an L-valve type loop seal.

[0035] The second steam generator 170 receives the solid particles from the high-temperature tank 160, exchanges heat between the solid particles and water, and cools the solid particles and heats the water to generate steam.

[0036] 2 is a diagram showing an example of the second steam generation section 170 according to the first embodiment. As shown in FIG. 2, the second steam generation section 170 includes a container 172, a dispersion plate 174a, an exhaust pipe 174b, a fluidizing gas supply section 176, and a heat transfer pipe 178.

[0037] The container 172 has, for example, a rectangular cylindrical shape. The dispersion plate 174a is provided in the container 172. The dispersion plate 174a extends horizontally and divides the inside of the container 172 into a storage chamber 172a and an air box chamber 172b. The dispersion plate 174a has a plurality of holes formed therein. 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 in the upper part of the container 172. The air box chamber 172b is formed below the storage chamber 172a in the container 172. The dispersion plate 174a functions as the bottom surface of the storage chamber 172a.

[0038] In this embodiment, the pipe 164 constituting the high-temperature particle supply unit 162 penetrates the upper surface of the container 172. The upper end of the pipe 164 is connected to the lower part of the high-temperature tank 160. The lower end of the pipe 164 is disposed in the accommodation chamber 172a. The lower end of the pipe 164 is located below the upper end of a pipe 166, which will be described later. In this embodiment, the lower end of the pipe 164 is located near the dispersion plate 174a.

[0039] The solid particles stored in the high-temperature bath 160 are supplied to the storage chamber 172a through the pipe 164. Therefore, the solid particles are stored in the storage chamber 172a.

[0040] The fluidizing gas supply unit 176 is, for example, a pump, a blower, etc. The suction side of the fluidizing gas supply unit 176 is connected to a fluidizing gas supply source. The discharge side of the fluidizing gas supply unit 176 is connected to the wind box chamber 172b. The fluidizing gas is, for example, water vapor, air, carbon dioxide, or combustion exhaust gas. The fluidizing gas supply unit 176 supplies the fluidizing gas into the wind box chamber 172b so that the superficial velocity of the fluidizing gas supplied into the storage chamber 172a through the dispersion plate 174a is equal to or greater than the minimum fluidizing velocity Umf and less than the terminal velocity. As a result, the solid particles supplied from the high-temperature tank 160 are fluidized by the fluidizing gas, and a fluidized bed (bubble fluidized bed) is formed in the storage chamber 172a. In addition, since the superficial velocity of the fluidizing gas supplied by the fluidizing gas supply unit 176 is less than the terminal velocity, the solid particles do not scatter from the storage chamber 172a.

[0041] A portion of the heat transfer tube 178 is disposed within the accommodation chamber 172a. A water supply unit 180 is connected to an inlet of the heat transfer tube 178. A heat utilization device 182 is connected to an outlet of the heat transfer tube 178.

[0042] In addition, an exhaust pipe 174b is connected to the upper surface of the container 172. The exhaust pipe 174b supplies the fluidizing gas to the heat utilization device 230 described later.

[0043] The water supply unit 180 supplies water to the heat transfer tube 178. The water supply unit 180 is, for example, a pump. The water supplied to the heat transfer tube 178 by the water supply unit 180 is supplied to the heat utilization device 182 through the outlet of the heat transfer tube 178. In the process of passing through the heat transfer tube 178, the water is heated by heat exchange with a fluidized bed of solid particles formed in the accommodation chamber 172a, and becomes water vapor. Therefore, water vapor is supplied to the heat utilization device 182.

[0044] The heat utilization equipment 182 is equipment that utilizes the thermal energy of the steam generated by the second steam generation unit 170. The heat utilization equipment 182 is, for example, a steam turbine generator (boiler), a boiler that provides steam, a furnace (furnace, kiln), and an air conditioning equipment.

[0045] In this embodiment, the pipe 166 constituting the high-temperature particle supply unit 162 connects the storage chamber 172a and the lower part of the heat exchanger 140. The upper end of the pipe 166 is connected to the side of the container 172 near the upper surface of the fluidized bed in the storage chamber 172a. The lower end of the pipe 166 is connected above the gas supply port 140a of the heat exchanger 140.

[0046] As described above, a fluidized bed of solid particles is formed in the storage chamber 172a. Therefore, when solid particles are supplied from the high-temperature tank 160 through the pipe 164, the supplied amount of solid particles is pushed out (overflows) into the pipe 166. Then, the pushed out solid particles, that is, the solid particles cooled by heat exchange with the water passing through the heat transfer tube 178, are supplied to the heat exchanger 140 through the pipe 166.

[0047] Returning to Fig. 1, the low temperature tank 200 stores solid particles that have been subjected to solid-gas separation by the solid-gas separator 150 and have a lower temperature than the solid particles stored in the high temperature tank 160. The low temperature tank 200 is supplied with solid particles at a different timing from that of the high temperature tank 160. The low temperature tank 200 is, for example, a hopper.

[0048] The low-temperature particle supply unit 202 supplies the solid particles stored in the low-temperature tank 200 to a first steam generation unit 210 (described later), and then supplies the solid particles to the heat exchanger 140. The low-temperature particle supply unit 202 includes pipes 204 and 206. The pipe 204 connects a lower portion of the low-temperature tank 200 and the first steam generation unit 210. The pipe 206 connects a lower portion of the first steam generation unit 210 and the heat exchanger 140.

[0049] The flow rate adjustment mechanism 208 is provided in the pipe 204. The flow rate adjustment mechanism 208 adjusts the flow rate of the solid particles supplied from the low temperature tank 200 to the first steam generation unit 210. The flow rate adjustment mechanism 208 is, for example, a J-valve type loop seal, an L-valve type loop seal, or a rotary valve.

[0050] The first water vapor generating section 210 generates water vapor by utilizing the heat of the solid particles stored in the low-temperature tank 200 .

[0051] Fig. 3 is a diagram showing an example of the first water vapor generation unit 210 according to the first embodiment. As shown in Fig. 3, the first water vapor generation unit 210 includes, for example, a heat pump system 300. The heat pump system 300 includes a circulation path 302, a compressor 310, a condenser 320, a pressure reduction unit 330, and an evaporator 340.

[0052] The circulation path 302 is a flow path through which a heat medium (refrigerant) circulates. In the circulation path 302, a compressor 310, a condenser 320, a pressure reducing section 330, and an evaporator 340 are provided.

[0053] The compressor 310 consumes electric power to compress the heat medium. The compressor 310 adiabatically compresses, for example, the heat medium in a gaseous state. The heat medium is heated by being compressed by the compressor 310.

[0054] The condenser 320 is provided downstream of the compressor 310 in the circulation path 302. The condenser 320 is a heat exchanger. The condenser 320 exchanges heat between the heat medium compressed by the compressor 310 and water, cools the heat medium to condense it, and heats the water to generate water vapor. The condenser 320 includes a water flow path 322 at a position where it can exchange heat with the heat medium circulating through the circulation path 302. A water supply unit 324 is connected to an inlet of the water flow path 322. A heat utilization device 326 is connected to an outlet of the water flow path 322.

[0055] The heat utilization device 326 is, for example, a device that heats, dries, sterilizes, cleans, or the like an object. The object is, for example, food. In the heat utilization device 326, the required temperature of the water vapor, that is, the temperature of the water vapor generated in the condenser 320, is, for example, 120°C or higher and 250°C or lower, and is preferably 150°C.

[0056] The pressure reducing unit 330 reduces the pressure of the heat medium in a gas-liquid mixed state condensed by the condenser 320. The pressure reducing unit 330, for example, reduces the pressure and expands the heat medium. As a result, the heat medium is further cooled and becomes a liquid state. The pressure reducing unit 330 is, for example, an expansion valve.

[0057] The evaporator 340 exchanges heat between the heat medium depressurized by the depressurization unit 330 and the solid particles supplied from the low-temperature tank 200, and heats the heat medium to vaporize it and cool the solid particles. In this embodiment, the evaporator 340 includes a storage unit 342, a dispersion plate 344, an exhaust pipe 346, and a fluidizing gas supply unit 348.

[0058] The accommodation section 342 is, for example, in the shape of a square cylinder. The dispersion plate 344 is provided in the accommodation section 342. The dispersion plate 344 extends horizontally and divides the accommodation section 342 into an accommodation chamber 342a and an air box chamber 342b. The dispersion plate 344 has a plurality of holes formed therein. The size of the plurality of holes is such that solid particles cannot pass through or have difficulty passing through. The accommodation chamber 342a is formed in the upper part of the accommodation section 342. The air box chamber 342b is formed below the accommodation chamber 342a in the accommodation section 342. The dispersion plate 344 functions as the bottom surface of the accommodation chamber 342a.

[0059] In this embodiment, the pipe 204 constituting the low-temperature particle supply unit 202 penetrates the upper surface of the accommodation unit 342. The upper end of the pipe 204 is connected to the lower part of the low-temperature tank 200. The lower end of the pipe 204 is disposed in the accommodation chamber 342a. The lower end of the pipe 204 is located lower than the upper end of a pipe 206 described later. In this embodiment, the lower end of the pipe 204 is located near the dispersion plate 344.

[0060] The solid particles stored in the low-temperature bath 200 are supplied to the storage chamber 342a through the pipe 204. Therefore, the solid particles are stored in the storage chamber 342a.

[0061] The fluidizing gas supply unit 348 is, for example, a pump, a blower, or the like. The suction side of the fluidizing gas supply unit 348 is connected to a fluidizing gas supply source. The discharge side of the fluidizing gas supply unit 348 is connected to the wind box chamber 342b. The fluidizing gas is, for example, water vapor, air, carbon dioxide, or combustion exhaust gas. The fluidizing gas supply unit 348 supplies the fluidizing gas into the wind box chamber 342b so that the superficial velocity of the fluidizing gas supplied into the storage chamber 342a through the dispersion plate 344 is equal to or greater than the minimum fluidizing velocity Umf and less than the terminal velocity. As a result, the solid particles supplied from the low-temperature tank 200 are fluidized by the fluidizing gas, and a fluidized bed (bubble fluidized bed) is formed in the storage chamber 342a. In addition, since the superficial velocity of the fluidizing gas supplied by the fluidizing gas supply unit 348 is less than the terminal velocity, the solid particles do not scatter from the storage chamber 342a.

[0062] An exhaust pipe 346 is connected to the upper surface of the storage section 342. The exhaust pipe 346 exhausts the fluidizing gas in the storage section 342 to the outside.

[0063] In addition, a portion of circulation path 302 between the downstream side of pressure reduction unit 330 and the upstream side of compressor 310 is disposed in storage chamber 342a. The heat medium decompressed by pressure reduction unit 330 is heated and vaporized by heat exchange with a fluidized bed of solid particles formed in storage chamber 342a while passing through circulation path 302 disposed in storage chamber 342a.

[0064] In this embodiment, the pipe 206 constituting the low-temperature particle supply unit 202 connects the accommodation chamber 342a and the lower part of the heat exchanger 140. The upper end of the pipe 206 is connected to the side of the accommodation unit 342 near the upper surface of the fluidized bed in the accommodation chamber 342a. The lower end of the pipe 206 is connected above the gas supply port 140a of the heat exchanger 140.

[0065] As described above, a fluidized bed of solid particles is formed in the accommodation chamber 342a. Therefore, when solid particles are supplied from the low-temperature bath 200 through the piping 204, the supplied amount of solid particles is pushed out (overflows) into the piping 206. Then, the pushed out solid particles, that is, the solid particles cooled by heat exchange with the heat medium passing through the circulation path 302, are supplied to the heat exchanger 140 through the piping 206.

[0066] Returning to FIG. 1, the gas sending unit 220 supplies the gas separated by the solid-gas separator 150 to the heat utilization device 230 or the preheater 120. The gas sending unit 220 includes pipes 222a and 222b and valves 224a and 224b. The pipe 222a connects the gas exhaust port of the solid-gas separator 150 to the heat utilization device 230. The valve 224a is provided in the pipe 222a. The pipe 222b connects the gas exhaust port of the solid-gas separator 150 to the preheater 120. The valve 224b is provided in the pipe 222b. In this embodiment, the valves 224a and 224b are exclusively opened and closed by the control unit 240.

[0067] The heat utilization equipment 230 is equipment that utilizes thermal energy contained in the gas separated by the solid-gas separator 150 or the fluidizing gas exhausted from the second steam generation section 170. The heat utilization equipment 230 is, for example, a gas turbine generator, a steam turbine generator (boiler), a boiler that provides steam, a furnace (furnace, kiln), or an air conditioning equipment.

[0068] The control unit 240 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit). The control unit 240 reads out programs and parameters for operating the CPU from the ROM. The control unit 240 manages and controls the entire energy storage device 100 in cooperation with a RAM as a work area and other electronic circuits. In this embodiment, the control unit 240 controls the gas supply unit 110 (blower 112), the heater 142, the switching unit 152 (valves 156a, 156b), the flow rate adjustment mechanism 168, the fluidizing gas supply unit 176, the water supply unit 180, the flow rate adjustment mechanism 208, the gas delivery unit 220 (valves 224a, 224b), the compressor 310, the water supply unit 324, and the fluidizing gas supply unit 348.

[0069] In this embodiment, the control unit 240 executes any one of a plurality of operation modes. The plurality of operation modes include, for example, at least a heat storage mode and a heat dissipation mode. The heat storage mode is a mode in which, during a period when there is a power surplus (i.e., generated power amount-demanded power amount>predetermined value (e.g., 0)) in the system in which the energy storage device 100 is installed, the surplus power is converted into thermal energy and stored. In other words, the heat storage mode is an operation mode in which the surplus power is converted into thermal energy and stored. The heat dissipation mode is an operation mode in which, when heat or power is needed in the system in which the energy storage device 100 is installed, the stored thermal energy is used by the heat utilization devices 182, 230, and 326. In other words, the heat dissipation mode is an operation mode in which the stored thermal energy is used by the heat utilization devices 182, 230, and 326. The amount of generated power is the amount of power generated by a power generation facility installed in the system in which the energy storage device 100 is installed. The demanded amount of power is the amount of power consumed by a consumer in the system in which the energy storage device 100 is installed.

[0070] In the initial state, the blower 112, the heater 142, the fluidizing gas supply units 176, 348, the water supply units 180, 324, and the compressor 310 are stopped, and the valves 156a, 156b, 224a, 224b, and the flow rate adjustment mechanisms 168, 208 are closed. In the initial state, the solid particles are stored in the low-temperature tank 200. The processing of the control unit 240 in the heat storage mode and the heat release mode will be described below.

[0071] [Heat storage mode] 4 is a diagram for explaining the processing of the control unit 240 in the heat storage mode. For ease of understanding, components that are not used in the heat storage mode are omitted in FIG.

[0072] The control unit 240 closes the valves 156b, 224a and the flow rate adjustment mechanism 168. The control unit 240 stops the fluidizing gas supply unit 176 and the water supply unit 180. As shown in FIG. 4, the control unit 240 supplies power to the blower 112 and the heater 142 to operate the heater. The control unit 240 also opens the valves 156a, 224b. The control unit 240 opens the flow rate adjustment mechanism 208 to adjust the opening degree. The control unit 240 then supplies power to operate the compressor 310, the water supply unit 324, and the fluidizing gas supply unit 348 to operate the heat pump system 300.

[0073] Then, the gas supplied to the air box chamber 130 by the blower 112 is supplied into the heat exchanger 140 through the gas supply port 140a. In addition, the heater 142 consumes surplus power, and the gas supplied into the heat exchanger 140 is heated by the heater 142. The heater 142 heats the gas to a first temperature that is lower than the heat-resistant temperature of the solid particles and satisfies the required temperature of the heat utilization device 182. For example, the heater 142 heats the gas so that the solid particles heated by the gas reach a second temperature that satisfies the required temperature. When the solid particles are silica, the gas is heated to 1600°C or less. In addition, 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.

[0074] In addition, solid particles are supplied from the low-temperature tank 200 to the accommodation chamber 342a of the evaporator 340 of the first steam generation unit 210. In addition, surplus power is consumed by the compressor 310, the water supply unit 324, and the fluidizing gas supply unit 348 of the heat pump system 300. Then, the fluidizing gas supply unit 348 supplies the fluidizing gas into the accommodation chamber 342a. As a result, a fluidized bed of solid particles at a fifth temperature (described later) is formed in the evaporator 340. In addition, the compressor 310 supplies the heat medium that has passed through the condenser 320 and the pressure reducing unit 330 to the circulation path 302 arranged in the accommodation chamber 342a. Therefore, in the evaporator 340, heat exchange is performed between the low-temperature heat medium and the solid particles at the fifth temperature. As a result, the heat medium is heated by the solid particles, and the solid particles are cooled by the heat medium. Thus, the heat medium heated in the evaporator 340 is further heated by being compressed by the compressor 310, and then supplied to the condenser 320. Then, water vapor is generated in the condenser 320 and supplied to the heat utilization device 326. The temperatures of the heat medium supplied to the compressor 310 and the solid particles discharged from the accommodation chamber 342a of the evaporator 340 are approximately the same, and are a third temperature. The third temperature is lower than the second temperature.

[0075] In the first steam generation section 210 , the solid particles at the third temperature are cooled from the fifth temperature by heat exchange with the heat medium, and are supplied to the heat exchanger 140 through the pipe 206 .

[0076] As described above, the heater 142 heats the gas to the first temperature in the heat exchanger 140, so that the high-temperature gas (gas at the first temperature) and the low-temperature solid particles are strongly agitated in the heat exchanger 140, and heat exchange occurs 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. At the outlet of the heat exchanger 140, the temperature of the solid particles and the temperature of the gas become substantially equal (the second temperature).

[0077] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the heat exchanger 140 into solid and gas. The high-temperature solid particles (solid particles at a second temperature) obtained by the solid-gas separation are supplied to the high-temperature tank 160 through a pipe 154a. The high-temperature tank 160 stores the high-temperature solid particles.

[0078] Meanwhile, the gas at the second temperature resulting from the solid-gas separation is supplied to the preheater 120 through the pipe 222b. The preheater 120 exchanges heat between the gas at the second temperature supplied from the solid-gas separator 150 through the pipe 222b and the gas supplied to the air box chamber 130 by the blower 112. Therefore, the gas supplied to the air box chamber 130 by the blower 112 is heated to a temperature higher than room temperature (e.g., 25°C) by the gas at the second temperature. In other words, the preheater 120 can preheat the gas before it is supplied to the air box chamber 130 with the heat of the gas discharged from the heat exchanger 140.

[0079] In this way, in the heat storage mode, the heater 142 converts the surplus power into heat, which is 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 surplus power is converted into thermal energy and is retained (stored) in the solid particles. Note that the heat capacity of solid particles is greater than that of gas (air), so the heat storage density (J / m 3 ) is higher than that of gases.

[0080] The control unit 240 adjusts the opening degree of the flow rate adjustment mechanism 208 based on the amount of surplus power (hereinafter referred to as "surplus power amount"). Specifically, when the heater 142 converts the surplus power amount into thermal energy and the solid particles are heated by this thermal energy (via gas), the amount of solid particles that will reach the second temperature is determined. Therefore, the control unit 240 adjusts the opening degree of the flow rate adjustment mechanism 208 so that the determined amount of solid particles is supplied to the heat exchanger 140.

[0081] As a result, even if the amount of surplus power fluctuates (if the amount of surplus power fluctuates over time), the temperature of the solid particles stored in the high-temperature tank 160 can be steadily maintained at the second temperature. In other words, it is possible to respond to fluctuations in the amount of surplus power. Therefore, in the heat dissipation mode described below, it is possible to supply water vapor at a fourth temperature that satisfies the required temperature to the heat utilization device 182 without using additional energy (for example, without burning auxiliary fuel).

[0082] In addition, in the heat storage mode, the heat pump system 300 (the compressor 310, the water supply unit 324, and the fluidizing gas supply unit 348) can be operated using surplus power. This makes it possible to supply water vapor to the heat utilization equipment 326 in the heat storage mode.

[0083] [Heat dissipation mode] 5 is a diagram for explaining the process of the control unit 240 in the heat dissipation mode. For ease of understanding, components that are not used in the heat dissipation mode are omitted in FIG.

[0084] The control unit 240 closes the valves 156a and 224b and the flow rate adjustment mechanism 208. The control unit 240 stops the heater 142, the compressor 310, the water supply unit 324, and the fluidizing gas supply unit 348. Furthermore, as shown in Fig. 5, the control unit 240 opens the valves 156b and 224a and opens the flow rate adjustment mechanism 168 to adjust the opening degree. The control unit 240 operates the blower 112, the fluidizing gas supply unit 176, and the water supply unit 180.

[0085] Then, the second steam generating section 170 is supplied with high-temperature solid particles (solid particles at the second temperature) from the high-temperature tank 160. In addition, the fluidizing gas supplying section 176 supplies the fluidizing gas into the accommodation chamber 172a. As a result, a fluidized bed of high-temperature solid particles is formed in the second steam generating section 170. In addition, water is supplied from the water supplying section 180 to the heat transfer tube 178. Therefore, in the second steam generating section 170, heat exchange is performed between the low-temperature water and the high-temperature solid particles. As a result, the water is heated by the solid particles, and the solid particles are cooled by the water. Thus, in the second steam generating section 170, the heated water is supplied to the heat utilization device 182. The temperature of the water supplied to the heat utilization device 182 and the temperature of the solid particles discharged from the second steam generating section 170 are approximately the same, and are the fourth temperature. The fourth temperature is a predetermined temperature that satisfies the required temperature of the heat utilization device 230. The fourth temperature is set so that a fifth temperature, which is the temperature of the solid particles stored in the low-temperature tank 200, is a temperature at which water vapor can be efficiently generated that satisfies the required temperature of the heat-utilization equipment 326. The fourth temperature is lower than the second temperature.

[0086] Then, in the second steam generating section 170, the solid particles at the fourth temperature, which are cooled from the second temperature by heat exchange with water, are supplied to the heat exchanger 140 through the pipe 166. Also, gas is supplied to the heat exchanger 140 from the blower 112 through the wind box chamber 130. As described above, the heater 142 is stopped and the valve 224b is closed, so the gas in the heat exchanger 140 is at, for example, room temperature. Therefore, in the heat exchanger 140, 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. The temperatures of the solid particles and the gas discharged from the heat exchanger 140 are approximately the same, and are the fifth temperature.

[0087] The solid-gas separator 150 separates the solid-gas mixture discharged from the heat exchanger 140 into solid and gas. The high-temperature gas (gas at the fifth temperature) obtained by the solid-gas separation is supplied to the heat utilization device 230 through the pipe 222a. The fifth temperature is a predetermined temperature at which steam that satisfies the required temperature of the heat utilization device 230 and satisfies the required temperature of the heat utilization device 326 can be efficiently generated. The fifth temperature is lower than the fourth temperature. The fluidizing gas heated to the fourth temperature in the second steam generation unit 170 is supplied to the heat utilization device 230 through the exhaust pipe 174b. As a result, the thermal energy of the gas is utilized in the heat utilization device 230 (for example, power generation). Meanwhile, the solid particles at the fifth temperature obtained by the solid-gas separation are supplied to the low-temperature tank 200 through the pipe 154b. The low-temperature tank 200 stores the solid particles at the fifth temperature.

[0088] Thus, in the heat dissipation mode, heat is exchanged between the high-temperature solid particles and the low-temperature water, and the heat is transferred to the water. Then, when needed (for example, during a period of power shortage), the high-temperature water (water at the fourth temperature) is used by the heat utilization device 182 (for example, to generate electricity).

[0089] The control unit 240 adjusts the opening degree of the flow rate adjustment mechanism 168 based on the required temperature and required flow rate of the heat utilization device 182. Specifically, when the water supply unit 180 supplies water to the heat transfer tube 178 of the second steam generation unit 170 at the required flow rate of the heat utilization device 182 and heats the water with solid particles at the second temperature stored in the high-temperature tank 160, the amount of solid particles for heating the water to the fourth temperature is determined. Therefore, the control unit 240 adjusts the opening degree of the flow rate adjustment mechanism 168 so that the determined amount of solid particles is supplied to the second steam generation unit 170.

[0090] This allows the temperature of the water supplied to the heat utilization equipment 182 to be the required temperature of the heat utilization equipment 182. Therefore, it is possible to stably supply water at the fourth temperature that satisfies the required temperature to the heat utilization equipment 182 without using additional energy (for example, without burning auxiliary fuel). Even if the required temperature of the heat utilization equipment 182 (for example, the required amount of power generation) fluctuates over time, it can be accommodated by adjusting the supply amount of solid particles.

[0091] In the heat pump system 300 operated in the heat storage mode, the amount of heat generated in the condenser 320 for one unit of power input to the compressor 310 is multiplied by the coefficient of performance (COP). Therefore, by increasing the COP, the amount of heat generated in the condenser 320 can be increased. The smaller the temperature difference between the evaporator 340 and the condenser 320, the larger the COP.

[0092] Therefore, in the heat dissipation mode, the control unit 240 adjusts the opening degree of the flow rate adjustment mechanism 168 for the next heat storage mode so that the difference between the temperature (fifth temperature) of the solid particles supplied to the evaporator 340 and the temperature of the water vapor generated in the condenser 320 is equal to or less than a predetermined value. This makes it possible to increase the COP and increase the amount of heat generated in the condenser 320 per unit amount of power input to the compressor 310. Therefore, when the energy storage device 100 executes the next heat storage mode, it becomes possible to efficiently generate water vapor in the condenser 320.

[0093] The predetermined value is, for example, 1° C. or more and 100° C. or less, preferably 30° C. or more and 60° C. or less, and more preferably 40° C. or more and 50° C. or less. Therefore, the fifth temperature is, for example, higher than room temperature (for example, 25° C.) and 250° C. or less.

[0094] Furthermore, in the heat exchanger 140, heat is exchanged between the solid particles discharged from the second steam generation unit 170 and the gas. In this way, the gas from which the heat of the solid particles has been recovered is supplied to the heat utilization device 230 through the solid-gas separator 150 and the pipe 222a. The heat utilization device 230 utilizes the heat of the gas. The configuration including the gas supply unit 110 and the heat exchanger 140 makes it possible to effectively utilize the heat of the solid particles after the water is heated to the fourth temperature.

[0095] As described above, the energy storage device 100 according to this embodiment converts surplus electricity into thermal energy and stores it in solid particles. This makes it possible to store energy at a lower cost than the conventional technology of storing surplus electricity in a secondary battery or the conventional technology of converting surplus electricity into hydrogen. Furthermore, compared to the conventional technology of converting surplus electricity into hydrogen and storing it, the stored energy can be quickly converted into thermal energy or electrical energy when needed (for example, when electricity is insufficient).

[0096] As described above, the energy storage device 100 according to this embodiment includes the first steam generating unit 210. This allows the temperature of the solid particles supplied to the heat exchanger 140 to be lowered compared to when the solid particles are directly supplied from the low temperature tank 200 to the heat exchanger 140. Therefore, in the heat storage mode, the temperature difference between the solid particles supplied to the heat exchanger 140 and the high-temperature gas supplied to the heat exchanger 140 can be increased. This allows the amount of heat storage of the solid particles that can store heat in the heat storage mode to be increased in the case of the same solid particles. Therefore, when the amount of heat storage of the solid particles that can store heat in the heat storage mode is made equal, the amount of solid particles circulating in the energy storage device 100 can be reduced, and the high temperature tank 160 and the low temperature tank 200 can be made smaller.

[0097] As described above, the first water vapor generating unit 210 according to this embodiment includes the heat pump system 300. The solid particles at the fifth temperature stored in the low-temperature tank 200 are at a temperature higher than room temperature. Therefore, the heat pump system 300 can increase the amount of heat generated in the condenser 320 compared to a conventional heat pump system in which the evaporator 340 is operated at room temperature. Therefore, the first water vapor generating unit 210 according to this embodiment can efficiently generate water vapor.

[0098] As described above, the evaporator 340 exchanges heat between the fluidized bed of solid particles and the heat medium. This allows efficient heat exchange between the solid particles and the heat medium. Therefore, the evaporator 340 allows efficient vaporization (evaporation) of the heat medium.

[0099] As described above, the energy storage device 100 includes the second water vapor generating section 170. The second water vapor generating section 170 exchanges heat between the solid particles at the second temperature stored in the high-temperature tank 160 and the water used by the heat utilization device 182. Therefore, the second water vapor generating section 170 can directly transfer the heat of the solid particles to the water. That is, the second water vapor generating section 170 can transfer the heat of the solid particles to the water without using another heat medium. Therefore, the second water vapor generating section 170 can efficiently heat the water. This allows the second water vapor generating section 170 to efficiently generate water vapor.

[0100] As described above, the energy storage device 100 includes the preheater 120. In the heat storage mode, the preheater 120 preheats the gas before being supplied to the heater 142 with the high-temperature gas separated by the solid-gas separator 150. This makes it possible to efficiently store the heat generated by the heater 142 in the heat storage mode.

[0101] [Second embodiment: energy storage device 400] FIG. 6 is a diagram for explaining an energy storage device 400 according to a second embodiment. As shown in FIG. 6, the energy storage device 400 includes a gas supply unit 110, a preheater 120, an air box chamber 130, a heat exchanger 140, a heater 142, a solid-gas separator 150, a switching unit 152, a high-temperature tank 160, a high-temperature particle supply unit 162, a flow rate adjustment mechanism 168, a second steam generation unit 170, a water supply unit 180, a heat utilization device 182, a low-temperature tank 200, a low-temperature particle supply unit 202, a flow rate adjustment mechanism 208, a first steam generation unit 410, a gas delivery unit 220, a heat utilization device 230, a third steam generation unit 430, and a control unit 440. In FIG. 6, solid arrows indicate the flow of solid particles and a solid-gas mixture. Also, dashed arrows indicate the flow of gas and water. Moreover, components that are substantially the same as those in the energy storage device 100 are given the same reference numerals and the description thereof will be omitted.

[0102] 7 is a diagram illustrating a first steam generating section 410 according to the second embodiment. As shown in FIG. 7, in this embodiment, the first steam generating section 410 includes a container section 412, a dispersion plate 414a, an exhaust pipe 414b, a fluidizing gas supply section 416, and a heat transfer pipe 418.

[0103] The accommodation section 412 is, for example, in the shape of a square cylinder. The dispersion plate 414a is provided in the accommodation section 412. The dispersion plate 414a extends in the horizontal direction and divides the accommodation section 412 into an accommodation chamber 412a and an air box chamber 412b. The dispersion plate 414a has a plurality of holes formed therein. The size of the plurality of holes is such that solid particles cannot pass through or have difficulty passing through. The accommodation chamber 412a is formed in the upper part of the accommodation section 412. The air box chamber 412b is formed below the accommodation chamber 412a in the accommodation section 412. The dispersion plate 414a functions as the bottom surface of the accommodation chamber 412a.

[0104] In this embodiment, the pipe 204 constituting the low-temperature particle supply unit 202 penetrates the upper surface of the accommodation unit 412. The upper end of the pipe 204 is connected to the lower part of the low-temperature tank 200. The lower end of the pipe 204 is disposed in the accommodation chamber 412a. The lower end of the pipe 204 is located below the upper end of a pipe 206 described later. In this embodiment, the lower end of the pipe 204 is located near the dispersion plate 414a.

[0105] The solid particles stored in the low-temperature bath 200 are supplied to the storage chamber 412a through the pipe 204. Therefore, the solid particles are stored in the storage chamber 412a.

[0106] The fluidizing gas supply unit 416 is, for example, a pump, a blower, or the like. The suction side of the fluidizing gas supply unit 416 is connected to a fluidizing gas supply source. The discharge side of the fluidizing gas supply unit 416 is connected to the wind box chamber 412b. The fluidizing gas is, for example, water vapor, air, carbon dioxide, or combustion exhaust gas. The fluidizing gas supply unit 416 supplies the fluidizing gas into the wind box chamber 412b so that the superficial velocity of the fluidizing gas supplied into the storage chamber 412a through the dispersion plate 414a is equal to or greater than the minimum fluidizing velocity Umf and less than the terminal velocity. As a result, the solid particles supplied from the low-temperature tank 200 are fluidized by the fluidizing gas, and a fluidized bed (bubble fluidized bed) is formed in the storage chamber 412a. In addition, since the superficial velocity of the fluidizing gas supplied by the fluidizing gas supply unit 416 is less than the terminal velocity, the solid particles do not scatter from the storage chamber 412a.

[0107] A portion of the heat transfer tube 418 is disposed inside the accommodation chamber 412a. The water supply unit 180 is connected to an inlet of the heat transfer tube 418. The heat utilization device 182 is connected to an outlet of the heat transfer tube 418.

[0108] Further, an exhaust pipe 414b is connected to the upper surface of the accommodation section 412. The exhaust pipe 414b exhausts the fluidizing gas in the accommodation section 412 to the outside.

[0109] The water supply unit 420 supplies water to the heat transfer tube 418. The water supply unit 420 is, for example, a pump. The water supplied to the heat transfer tube 418 by the water supply unit 420 is supplied to the heat utilization device 422 through the outlet of the heat transfer tube 418. In the process of passing through the heat transfer tube 418, the water is heated by heat exchange with a fluidized bed of solid particles formed in the accommodation chamber 412a, and becomes water vapor. Therefore, water vapor is supplied to the heat utilization device 422.

[0110] The heat utilization device 422 is a device that utilizes the thermal energy of the water vapor generated by the first water vapor generation unit 410. The heat utilization device 422 is, for example, a device that heats, dries, sterilizes, cleans, or the like an object. The object is, for example, food. The temperature of the water vapor required by the heat utilization device 422 is, for example, 120°C or more and 250°C or less, and is preferably 150°C.

[0111] In this embodiment, the pipe 206 constituting the low-temperature particle supply unit 202 connects the accommodation chamber 412a and the lower part of the heat exchanger 140. The upper end of the pipe 206 is connected to the side of the accommodation unit 412 near the upper surface of the fluidized bed in the accommodation chamber 412a. The lower end of the pipe 206 is connected above the gas supply port 140a of the heat exchanger 140.

[0112] As described above, a fluidized bed of solid particles is formed in the accommodation chamber 412a. Therefore, when solid particles are supplied from the low-temperature tank 200 through the pipe 204, the supplied amount of solid particles is pushed out (overflows) into the pipe 206. Then, the pushed out solid particles, that is, the solid particles cooled by heat exchange with the water passing through the heat transfer tube 418, are supplied to the heat exchanger 140 through the pipe 206.

[0113] 6, the third steam generator 430 is provided in the pipe 154b between the valve 156b and the low-temperature tank 200. The third steam generator 430 exchanges heat between the solid particles separated by the solid-gas separator 150 and water to cool the solid particles and heat the water to generate steam. The solid particles cooled by the third steam generator 430 are supplied to the low-temperature tank 200.

[0114] The third steam generating section 430 is, for example, a heat exchanger that exchanges heat between a fluidized bed of solid particles and water, similar to the first steam generating section 410. The third steam generating section 430 may be a heat exchanger that exchanges heat between a moving bed of solid particles and water. The steam generated by the third steam generating section 430 is supplied to the heat utilization device 422.

[0115] The control unit 440 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit). The control unit 440 reads out a program, parameters, and the like for operating the CPU from the ROM. The control unit 440 manages and controls the entire energy storage device 400 in cooperation with a RAM as a work area and other electronic circuits. In this embodiment, the control unit 440 controls the gas supply unit 110 (blower 112), the heater 142, the switching unit 152 (valves 156a, 156b), the flow rate adjustment mechanism 168, the fluidizing gas supply unit 176, the water supply unit 180, the flow rate adjustment mechanism 208, the fluidizing gas supply unit 416, the water supply unit 420, the third steam generation unit 430, and the gas delivery unit 220 (valves 224a, 224b).

[0116] In the initial state, the blower 112, the heater 142, the fluidizing gas supply units 176, 416, the water supply units 180, 420, and the third steam generation unit 430 are stopped, and the valves 156a, 156b, 224a, 224b, and the flow rate adjustment mechanisms 168, 208 are closed. In the initial state, the solid particles are stored in the low-temperature tank 200. The processing of the control unit 440 in the heat storage mode and the heat release mode will be described below.

[0117] [Heat storage mode] 8 is a diagram for explaining the process of the control unit 440 in the heat storage mode. For ease of understanding, components that are not used in the heat storage mode are omitted in FIG.

[0118] The control unit 440 closes the valves 156b and 224a and the flow rate adjustment mechanism 168. The control unit 440 stops the fluidizing gas supply unit 176 and the water supply unit 180. As shown in Fig. 3, the control unit 440 also operates the blower 112, the heater 142, the fluidizing gas supply unit 416, and the water supply unit 420. The control unit 440 also opens the valves 156a and 224b. The control unit 440 opens the flow rate adjustment mechanism 208 to adjust the opening degree.

[0119] Then, the gas supplied to the air box chamber 130 by the blower 112 is supplied into the heat exchanger 140 through the gas supply port 140a. Furthermore, surplus power is consumed by the heater 142, and the gas supplied into the heat exchanger 140 is heated by the heater 142. The heater 142 heats the gas to a first temperature.

[0120] In addition, solid particles are supplied from the low-temperature tank 200 to the accommodation chamber 412a of the accommodation unit 412 of the first steam generation unit 410. In addition, surplus power is supplied to the fluidizing gas supply unit 416 and the water supply unit 420. Then, the fluidizing gas supply unit 416 supplies the fluidizing gas into the accommodation chamber 412a. As a result, a fluidized layer of solid particles at the fifth temperature is formed in the accommodation unit 412. In addition, water is supplied from the water supply unit 420 to the heat transfer tube 418. Therefore, in the first steam generation unit 410, heat exchange is performed between the low-temperature water and the high-temperature solid particles. As a result, the water is heated by the solid particles, and the solid particles are cooled by the water. Thus, in the first steam generation unit 410, the heated water is supplied to the heat utilization device 422.

[0121] In the first steam generation section 410 , the solid particles at the third temperature are cooled from the sixth temperature by heat exchange with the heat medium, and are supplied to the heat exchanger 140 through the pipe 206 .

[0122] As described above, the heated high-temperature gas (gas at the first temperature) is supplied to the heat exchanger 140, where the high-temperature gas and the low-temperature solid particles are strongly agitated, and heat exchange occurs 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. At the outlet of the heat exchanger 140, the temperature of the solid particles and the temperature of the gas become substantially equal (the second temperature).

[0123] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the heat exchanger 140 into solid and gas. The high-temperature solid particles (solid particles at a second temperature) obtained by the solid-gas separation are supplied to the high-temperature tank 160 through a pipe 154a. The high-temperature tank 160 stores the high-temperature solid particles.

[0124] [Heat dissipation mode] 9 is a diagram for explaining the process of the control unit 440 in the heat dissipation mode. For ease of understanding, components that are not used in the heat dissipation mode are omitted in FIG.

[0125] The control unit 440 closes the valves 156a, 224b and the flow rate adjustment mechanism 208. The control unit 440 stops the heater 142. Furthermore, as shown in Fig. 4, the control unit 440 opens the valves 156b, 224a and opens the flow rate adjustment mechanism 168 to adjust the opening degree. The control unit 440 operates the blower 112, the fluidizing gas supply unit 176, the water supply unit 180, and the third steam generation unit 430.

[0126] Then, high-temperature solid particles (solid particles at the second temperature) are supplied from the high-temperature tank 160 to the second steam generating section 170. In addition, the fluidizing gas supplying section 176 supplies the fluidizing gas into the accommodation chamber 172a. As a result, a fluidized layer of high-temperature solid particles is formed in the second steam generating section 170. In addition, water is supplied from the water supplying section 180 to the heat transfer tube 178. Therefore, in the second steam generating section 170, heat exchange is performed between the low-temperature water and the high-temperature solid particles. As a result, the water is heated by the solid particles, and the solid particles are cooled by the water. Thus, in the second steam generating section 170, the heated water is supplied to the heat utilization device 182. The temperature of the water supplied to the heat utilization device 182 and the temperature of the solid particles discharged from the second steam generating section 170 are approximately equal to each other, and are the fourth temperature.

[0127] Then, in the second steam generating section 170, the solid particles at the fourth temperature are cooled from the second temperature by heat exchange with water and are supplied to the heat exchanger 140 through the pipe 166 constituting the high-temperature particle supplying section 162. Also, gas is supplied to the heat exchanger 140 from the blower 112 through the wind box chamber 130. Therefore, in the heat exchanger 140, 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. The temperatures of the solid particles and gas discharged from the heat exchanger 140 are approximately the same, that is, the fifth temperature.

[0128] Then, the solid-gas separator 150 separates the solid-gas mixture discharged from the heat exchanger 140 into solid and gas. The high-temperature gas (gas at a fifth temperature) resulting from the solid-gas separation is supplied to the heat utilization equipment 230 through the pipe 222a. The fifth temperature is a predetermined temperature that satisfies the required temperature of the heat utilization equipment 230 and is lower than the fourth temperature. The fluidizing gas heated to the fourth temperature in the second steam generation section 170 is supplied to the heat utilization equipment 230 through the exhaust pipe 174b. As a result, the thermal energy of the gas is utilized (for example, power generation) in the heat utilization equipment 230.

[0129] Meanwhile, the solid particles at the fifth temperature after solid-gas separation are supplied to the third steam generator 430. Then, in the third steam generator 430, steam is generated by the heat of the solid particles at the fifth temperature. As a result, the cooled solid particles at the sixth temperature are supplied to the low temperature tank 200 through the pipe 154b. The low temperature tank 200 stores the solid particles at the sixth temperature.

[0130] Thus, in the heat dissipation mode, heat is exchanged between the high-temperature solid particles and the low-temperature water in the second steam generation section 170, and the 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 fourth temperature) is used by the heat utilization device 182 (for example, to generate electricity).

[0131] The control unit 440 adjusts the opening degree of the flow rate adjustment mechanism 168 based on the required temperature and required flow rate of the heat utilization device 182. Specifically, when the water supply unit 180 supplies water to the heat transfer tube 178 of the second steam generation unit 170 at the required flow rate of the heat utilization device 182 and heats the water with solid particles at the second temperature stored in the high-temperature tank 160, the amount of solid particles for heating the water to the fourth temperature is determined. Therefore, the control unit 440 adjusts the opening degree of the flow rate adjustment mechanism 168 so that the determined amount of solid particles is supplied to the second steam generation unit 170.

[0132] This allows the temperature of the water supplied to the heat utilization equipment 182 to be the required temperature of the heat utilization equipment 182. Therefore, it is possible to stably supply water at the fourth temperature that satisfies the required temperature to the heat utilization equipment 182 without using additional energy (for example, without burning auxiliary fuel). Even if the required temperature of the heat utilization equipment 182 (for example, the required amount of power generation) fluctuates over time, it can be accommodated by adjusting the supply amount of solid particles.

[0133] Furthermore, in the heat exchanger 140, heat is exchanged between the solid particles discharged from the second steam generation unit 170 and the gas. In this way, the gas from which the heat of the solid particles has been recovered is supplied to the heat utilization device 230 through the solid-gas separator 150 and the pipe 222a. The heat utilization device 230 utilizes the heat of the gas. The configuration including the gas supply unit 110 and the heat exchanger 140 makes it possible to effectively utilize the heat of the solid particles after the water is heated to the fourth temperature.

[0134] As described above, the energy storage device 400 according to this embodiment converts surplus electricity into thermal energy and stores it in solid particles. This makes it possible to store energy at a lower cost than the conventional technology of storing surplus electricity in a secondary battery or the conventional technology of converting surplus electricity into hydrogen. Furthermore, compared to the conventional technology of converting surplus electricity into hydrogen and storing it, the stored energy can be quickly converted into thermal energy or electrical energy when needed (for example, when electricity is insufficient).

[0135] As described above, the energy storage device 400 according to this embodiment includes the first steam generating unit 410. This allows the temperature of the solid particles supplied to the heat exchanger 140 to be lowered compared to when the solid particles are directly supplied from the low temperature tank 200 to the heat exchanger 140. Therefore, in the heat storage mode, the temperature difference between the solid particles supplied to the heat exchanger 140 and the high-temperature gas supplied to the heat exchanger 140 can be increased. This allows the amount of heat stored in the solid particles that can store heat in the heat storage mode to be increased in the case of the same solid particles. Therefore, when the amount of heat stored in the solid particles that can store heat in the heat storage mode is made equal, the amount of solid particles circulating in the energy storage device 400 can be reduced, and the high temperature tank 160 and the low temperature tank 200 can be made smaller.

[0136] As described above, the first steam generating section 410 exchanges heat between the fluidized bed of solid particles and water. This allows the first steam generating section 410 to transfer heat from the solid particles directly to the water. That is, the first steam generating section 410 can transfer heat from the solid particles to the water without using another heat medium. This allows the first steam generating section 410 to efficiently heat the water. This allows the first steam generating section 410 to efficiently generate steam.

[0137] As described above, the energy storage device 400 includes the third water vapor generating section 430. This allows the energy storage device 400 to generate water vapor in the third water vapor generating section 430 in addition to the second water vapor generating section 170 in the heat dissipation mode.

[0138] In the heat dissipation mode, the flow rate of the water supplied by the water supply unit 180 is set to the flow rate required by the heat utilization device 182, and the amount of solid particles supplied to the second steam generation unit 170 is adjusted, so that the temperature of the water supplied to the heat utilization device 182 can be set to the required temperature of the heat utilization device 182. Therefore, it is possible to respond to temporal load fluctuations of the heat utilization device 182 without requiring auxiliary fuel.

[0139] As described above, the second steam generating section 170 exchanges heat between the solid particles at the second temperature stored in the high-temperature tank 160 and the water used by the heat utilization device 182. Therefore, the second steam generating section 170 can directly transfer the heat of the solid particles to the water. That is, the second steam generating section 170 can transfer the heat of the solid particles to the water without using another heat medium. Therefore, the second steam generating section 170 can efficiently heat the water. This allows the heat utilization device 182 to efficiently utilize the heat stored by the solid particles.

[0140] Although the embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to the above-described embodiments. It is clear that a person skilled in the art can think of various modified or altered examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0141] For example, in the above-described embodiment, the gas supply unit 110 is described as including the blower 112. However, the gas supply unit 110 is not limited to a specific configuration as long as it can supply gas to the heat exchanger 140. For example, the gas supply unit 110 may include a compressed gas source (e.g., a compressed air source) or a pump instead of the blower 112.

[0142] In the above embodiment, the configuration in which gas is supplied from the bottom surface of the heat exchanger 140 has been described as an example. However, the gas may be supplied from below the supply point of the solid particles in the heat exchanger 140. For example, the gas may be supplied from the lower part of the heat exchanger 140. Furthermore, the gas supply unit 110 may supply gas at normal pressure or may supply pressurized gas.

[0143] In the above first embodiment, the evaporator 340 of the first steam generating unit 210 is described as forming a fluidized bed of solid particles. This allows the heat medium to be efficiently heated by the heat of the solid particles in the heat storage mode. However, the evaporator 340 of the first steam generating unit 210 is not limited to a specific configuration as long as it can exchange heat between the solid particles and the heat medium. The storage unit 342 of the evaporator 340 may form a moving bed of solid particles, for example.

[0144] Similarly, in the above second embodiment, the first steam generating section 410 is described as forming a fluidized bed of solid particles. This allows water to be efficiently heated by the heat of the solid particles in the heat storage mode. However, the first steam generating section 410 is not limited to a specific configuration as long as it can exchange heat between the solid particles and water. For example, the container section 412 of the first steam generating section 410 may form a moving bed of solid particles.

[0145] Similarly, in the above embodiment, the second steam generating section 170 is described as forming a fluidized bed of solid particles. This allows water to be efficiently heated by the heat of the solid particles in the heat dissipation mode. However, the second steam generating section 170 is not limited to a specific configuration as long as it can exchange heat between the solid particles and water. For example, the container 172 of the second steam generating section 170 may form a moving bed of solid particles.

[0146] In the above embodiment, the period when there is a surplus of power (power generation amount - power demand amount > a predetermined value (e.g. 0)) is the heat storage mode. However, the heat storage mode may be used when it is necessary to convert power to other energy (e.g. when power needs to be consumed to stabilize the power grid). Also, the heat dissipation mode is used when necessary. However, the heat dissipation mode may be used when it is necessary to utilize heat (e.g. when it is desired to utilize heat in a cement factory).

[0147] A heater may also be installed inside the wind box chamber 130 .

[0148] This disclosure can, for example, contribute to Sustainable Development Goal (SDG) Goal 7: "Ensure access to affordable, reliable, sustainable and modern energy." [Explanation of symbols]

[0149] 100 Energy storage device 110 Gas supply section 142 Heater 140 Heat exchanger 140a Gas supply port 150 Solid-gas separator 160 High temperature bath 162 High temperature particle supply section 168 Flow rate adjustment mechanism 170 Second steam generating section 200 Cryostat 202 Low Temperature Particle Supply Section 210 First steam generating section 240 Control Unit 300 Heat Pump System 302 Circulation route 310 Compressor 320 Condenser 330 Pressure reduction section 340 Evaporator 342 Storage unit 348 Fluidizing Gas Supply Section 400 Energy storage device 410 First steam generating unit 412 Storage unit 416 Fluidizing Gas Supply Section 418 Heat transfer tube 430 Third Steam Generator

Claims

1. a heat exchanger into which a gas is supplied from a gas supply port formed on a bottom surface or a lower portion, into which solid particles are supplied from above through the gas supply port, and which exchanges heat between the gas and the solid particles; A gas supply unit that supplies gas to the heat exchanger; a heater that consumes electric power to heat either or both of the gas supplied from the gas supply unit to the heat exchanger and the gas in the heat exchanger; a solid-gas separator for separating the solid-gas mixture discharged from the heat exchanger into solid and gas; a high-temperature tank for storing the solid particles separated by the solid-gas separator; a high-temperature particle supply unit that supplies the solid particles stored in the high-temperature tank to the 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 first water vapor generating unit that generates water vapor by utilizing heat of the solid particles stored in the low-temperature tank; a low-temperature particle supply unit that supplies solid particles from the first steam generation unit to the heat exchanger; An energy storage device comprising:

2. The first water vapor generating unit includes a heat pump system, The heat pump system includes: A compressor that consumes electricity to compress a heat medium; a condenser that performs heat exchange between the heat medium compressed by the compressor and water, and cools the heat medium to condense the heat medium and heats the water to generate water vapor; a pressure reducing unit that reduces the pressure of the heat medium condensed by the condenser; an evaporator that performs heat exchange between the heat medium decompressed by the decompression unit and the solid particles supplied from the low-temperature tank, and heats the heat medium to vaporize the heat medium and cool the solid particles; The energy storage device of claim 1 .

3. a second steam generating section to which the solid particles are supplied from the high-temperature tank, and which performs heat exchange between the solid particles and water to cool the solid particles and heat the water to generate steam; a flow rate adjusting mechanism for adjusting a flow rate of the solid particles supplied from the high-temperature tank to the second steam generating unit; Equipped with The energy storage device according to claim 2 , wherein the high-temperature particle supplying unit supplies the solid particles cooled by the second steam generating unit to the heat exchanger.

4. a control unit that controls the gas supply unit, the heater, the flow rate adjustment mechanism, the low-temperature particle supply unit, and the compressor; The control unit is Execute any one of a plurality of operation modes; The plurality of operation modes include a heat storage mode and a heat release mode, In the heat storage mode, controlling the gas supply unit to supply gas to the heat exchanger, supplying power to the heater to heat the gas, controlling the low-temperature particle supply unit to supply the solid particles from the low-temperature tank to the heat exchanger through the first steam generator, heating the solid particles with the gas in the heat exchanger, and supplying the solid particles separated by the solid-gas separator to the high-temperature tank; providing power to the compressor to operate the heat pump system; In the heat dissipation mode, 4. The energy storage device according to claim 3, wherein the flow rate adjustment mechanism is controlled to supply the solid particles from the high temperature tank to the second steam generation unit, the solid particles are supplied from the second steam generation unit to the heat exchanger through the high temperature particle supply unit, the heater is stopped, and the gas supply unit is controlled to supply gas to the heat exchanger, the gas is heated by the solid particles in the heat exchanger, and the solid particles separated by the solid-gas separator are supplied to the low temperature tank, so that a difference between a temperature of the solid particles supplied to the evaporator and a temperature of the steam generated in the condenser is not more than a predetermined value.

5. The evaporator comprises: a container for containing the solid particles supplied from the low-temperature tank; a circulation path provided in the accommodation portion and through which the heat medium decompressed by the decompression portion passes; a fluidizing gas supply unit that supplies a fluidizing gas from a bottom surface or a lower portion of the container unit to form a fluidized bed of the solid particles in the container unit; The energy storage device according to claim 2 or 3, comprising:

6. The first water vapor generating unit is a container for containing the solid particles supplied from the low-temperature tank; a heat transfer tube provided in the housing portion and through which water passes; The energy storage device of claim 1 .

7. 7. The energy storage device according to claim 6, further comprising a fluidizing gas supply unit that forms a fluidized bed of the solid particles in the storage unit by supplying a fluidizing gas from a bottom surface or a lower portion of the storage unit.

8. a third steam generating unit that performs heat exchange 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 energy storage device according to claim 6 or 7, wherein the low-temperature tank stores the solid particles after heat exchange by the third steam generating section.

9. a control unit that controls the gas supply unit, the heater, the high-temperature particle supply unit, and the low-temperature particle supply unit; The control unit is Execute any one of a plurality of operation modes; The plurality of operation modes include a heat storage mode and a heat release mode, In the heat storage mode, controlling the gas supply unit to supply gas to the heat exchanger, supplying power to the heater to heat the gas, controlling the low-temperature particle supply unit to supply the solid particles from the first steam generation unit to the heat exchanger, heating the solid particles with the gas in the heat exchanger, and supplying the solid particles separated by the solid-gas separator to the high-temperature tank; In the heat dissipation mode, 9. The energy storage device according to claim 8, further comprising: controlling the high-temperature particle supply unit to supply the solid particles from the high-temperature tank to the heat exchanger; stopping the heater; controlling the gas supply unit to supply gas to the heat exchanger; heating the gas with the solid particles in the heat exchanger; supplying the solid particles separated by the solid-gas separator to the third steam generation unit; and supplying the solid particles from the third steam generation unit to the low-temperature tank.

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