Fluidized bed based solid particle thermal storage system

Abstract

This application discloses a fluidized bed-based solid particle thermal storage system, including a cold feed buffer silo, a heating unit, a hot storage tank, a heat exchange unit, and a cold storage tank. The cold feed buffer silo is suitable for storing low-temperature solid particles. The heating unit is connected to the cold feed buffer silo and is suitable for heat exchange and temperature increase of the low-temperature solid particles. The hot storage tank is connected to the heating unit and is suitable for storing high-temperature solid particles. The heat exchange unit is connected to the hot storage tank and is suitable for heat exchange and temperature decrease of the high-temperature solid particles. The cold storage tank is connected to the heat exchange unit and is suitable for storing low-temperature solid particles. The cold feed buffer silo is located above the heating unit. A particle elevator is installed between the cold feed buffer silo and the cold storage tank to transport the low-temperature solid particles from the cold storage tank to the cold feed buffer silo. The low-temperature solid particles in the cold feed buffer silo are suitable for entering the heating unit under gravity. This application adopts a combination of gravity flow regulation and mechanical flow stabilization to achieve rapid load regulation while ensuring stable system operation.

Description

Technical Field

[0001] This application relates to the fields of thermal energy storage and power grid regulation technology, and in particular to a solid particle thermal energy storage system based on a fluidized bed. Background Technology

[0002] The grid-connected scale of renewable energy sources such as wind and solar power is increasing year by year, but their volatility poses a severe challenge to the flexibility of thermal power units, and the grid's demand for rapid frequency regulation and deep peak shaving resources is becoming increasingly urgent. Upgrading thermal power units to improve flexibility and coupling them with large-scale, long-term, and low-cost energy storage technologies is one of the key paths to solving this problem. Among them, solid particle thermal energy storage technology, due to its advantages such as wide temperature range (up to over 1000℃), high safety, high thermal density, low cost, and long lifespan, is a key technical route for solving the flexibility upgrade of thermal power units and long-term energy storage.

[0003] However, the heat transfer process in solid particle thermal storage systems involves the circulation of solid particles within the system. Related technologies typically employ mechanical conveying equipment such as particle feeders and conveyors, or drive the particles using high-power fans and pumps, to achieve circulation between different units. This flow process has a slow response speed. This makes the grid's rapid load adjustment function highly dependent on the operation of high-inertia mechanical conveying equipment (such as elevators, fans, and pumps), resulting in problems such as slow system response. Furthermore, rapid load changes can affect the service life of mechanical equipment. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, one objective of this application is to propose a fluidized bed-based solid particle thermal storage system, which aims to solve the problems of slow response speed and short equipment life caused by the coupling of heat exchange and particle transport functions in existing particle thermal storage systems.

[0005] This application proposes a fluidized bed-based solid particle thermal storage system, comprising a cold feed buffer silo, a heating unit, a hot storage tank, a heat exchange unit, and a cold storage tank. The cold feed buffer silo is suitable for storing low-temperature solid particles. The heating unit is connected to the cold feed buffer silo, and the low-temperature solid particles are suitable for heat exchange and heating in the heating unit. The hot storage tank is connected to the heating unit and is suitable for storing high-temperature solid particles from the heating unit. The heat exchange unit is connected to the hot storage tank, and the high-temperature solid particles are suitable for heat exchange and cooling in the heat exchange unit. The cold storage tank is connected to the heat exchange unit and is suitable for storing low-temperature solid particles from the heat exchange unit. The cold feed buffer silo is located above the heating unit. A particle elevator is provided between the cold feed buffer silo and the cold storage tank, and the particle elevator is suitable for conveying low-temperature solid particles from the cold storage tank to the cold feed buffer silo. The low-temperature solid particles in the cold feed buffer silo are suitable for entering the heating unit under gravity. The heating unit and / or the heat exchange unit include a fluidized bed assembly to facilitate heat exchange of solid particles in a fluidized state.

[0006] According to some embodiments of this application, a heat storage tank is disposed above a heat exchange unit, and high-temperature solid particles in the heat storage tank are adapted to enter the heat exchange unit under the action of gravity.

[0007] According to some embodiments of this application, control valves are provided at the outlets of the cold material buffer silo, the hot storage tank, and the cold storage tank. The control valves are adapted to adjust the opening degree to control the flow rate of solid particles.

[0008] According to some embodiments of this application, the heating unit includes a fluidized bed electric heater and a fluidizing gas pipeline. The fluidized bed electric heater is connected to a cold material buffer bin and a hot storage tank. Multiple fluidizing gas inlets are formed at the bottom of the fluidized bed electric heater. The fluidizing gas pipeline is connected to the multiple fluidizing gas inlets to facilitate the introduction of fluidizing gas into the fluidized bed electric heater.

[0009] According to some embodiments of this application, the heating unit further includes a hot gas pipeline and a preheater. The hot gas pipeline is connected to the fluidized bed electric heater to facilitate the output of high-temperature gas from the fluidized bed electric heater. The fluidized gas pipeline and the hot gas pipeline are connected to the preheater to facilitate heat exchange between the high-temperature gas and the fluidized gas in the preheater to preheat the fluidized gas.

[0010] According to some embodiments of this application, multiple heating components are spaced apart inside the fluidized bed electric heater.

[0011] According to some embodiments of this application, the heat exchange unit includes a heat exchanger and a heat exchange pipeline. A heat exchange cavity is formed inside the heat exchanger, and the heat exchange cavity connects a hot storage tank and a cold storage tank. A portion of the heat exchange pipeline is disposed in the heat exchange cavity. One end of the heat exchange pipeline extends outside the heat exchanger and forms a cold steam inlet, and the other end of the heat exchange pipeline extends outside the heat exchanger and forms a hot steam outlet.

[0012] According to some embodiments of this application, the diameter of the portion of the wall connected to the outlet of the cold material buffer silo, hot storage tank, and / or cold storage tank gradually decreases along the flow direction of the solid particles.

[0013] According to some embodiments of this application, the solid particles are selected from one or more of sand, quartz sand, ceramic particles, and silicon carbide particles.

[0014] According to some embodiments of this application, the cold material buffer bin, heating unit, hot storage tank, heat exchange unit, and cold storage tank are arranged sequentially from high to low along the height direction.

[0015] This application utilizes a high-level cold material buffer silo to decompose the material circulation of a solid particle thermal storage system into two independent processes: "stable lifting" and "rapid response." It employs a combination of gravity flow regulation and mechanical flow stabilization to achieve rapid load adjustment while ensuring stable system operation. The high-level buffer silo's regulating function protects critical conveying equipment from frequent load fluctuations. This application achieves a second-level rapid response through gravity flow regulation, solving the problem of slow response speed in traditional thermal storage systems caused by the large inertia of mechanical conveying equipment. Simultaneously, by stabilizing the operation of the mechanical conveying equipment, it significantly reduces equipment wear and extends equipment lifespan. Furthermore, it offers advantages such as simple control, reliable operation, and low maintenance costs, effectively enhancing the practical value and economic efficiency of thermal storage systems in power grid frequency regulation.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a schematic diagram of the structure of a fluidized bed-based solid particle thermal storage system according to some embodiments of this application.

[0019] Figure label: 1. Cold material buffer bin; 2. Fluidized bed electric heater; 3. Fluidizing gas pipeline; 4. Hot gas pipeline; 5. Preheater; 6. Fluidizing gas; 7. High temperature gas; 8. Hot storage tank; 9. Heat exchanger; 10. Heat exchange pipeline; 11. Cold steam; 12. Hot steam; 13. Cold storage tank; 14. Particle elevator; 15. First valve; 16. Second valve; 17. Third valve. Detailed Implementation

[0020] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0021] The following is for reference. Figure 1 This application describes a fluidized bed-based solid particle thermal storage system according to embodiments of the present application.

[0022] This application proposes a fluidized bed-based solid particle thermal storage system, comprising a cold feed buffer silo 1, a heating unit, a hot storage tank 8, a heat exchange unit, and a cold storage tank 13. The cold feed buffer silo 1 is suitable for storing low-temperature solid particles. The heating unit is connected to the cold feed buffer silo 1, and the low-temperature solid particles are suitable for heat exchange and temperature increase in the heating unit. The hot storage tank 8 is connected to the heating unit and is suitable for storing high-temperature solid particles from the heating unit. The heat exchange unit is connected to the hot storage tank 8, and the high-temperature solid particles are suitable for heat exchange and temperature decrease in the heat exchange unit. The cold storage tank... 13 is connected to the heat exchange unit, and the cold storage tank 13 is suitable for storing low-temperature solid particles from the heat exchange unit; wherein, the cold material buffer bin 1 is disposed above the heating unit; a particle elevator 14 is disposed between the cold material buffer bin 1 and the cold storage tank 13, and the particle elevator 14 is suitable for conveying the low-temperature solid particles from the cold storage tank 13 to the cold material buffer bin 1; the low-temperature solid particles in the cold material buffer bin 1 are suitable for entering the heating unit under the action of gravity; the heating unit and / or the heat exchange unit includes a fluidized bed assembly to facilitate heat exchange of solid particles in a fluidized state.

[0023] According to the solid particle thermal storage system of this application, a closed-loop system for solid particle thermal storage and release is formed by a cold material buffer silo 1, a heating unit, a hot storage tank 8, a heat exchange unit, a cold storage tank 13, and a particle elevator 14. This system has a dual-loop architecture, including a "stable lifting loop" composed of the particle elevator 14, the cold storage tank 13, and the cold material buffer silo 1, and a "dynamic response loop" composed of the cold material buffer silo 1, the heating unit, the hot storage tank 8, the heat exchange unit, and the cold storage tank 13. The heating unit uses electrical energy to heat the solid particles, changing them from low-temperature solid particles to high-temperature solid particles, thus completing the thermal storage process. Simultaneously, the thermal storage process consumes electricity, which can increase the load on the power grid system. The heat exchange unit uses the thermal energy of the high-temperature solid particles to heat the cold steam 11, resulting in low-temperature solid particles and hot steam 12, completing the heat release process. Simultaneously, the high-temperature solid particles provide the heat source for steam heating, which can reduce the electrical energy consumption of heating steam, thereby reducing the load on the power grid system. The heating unit and / or heat exchange unit includes a fluidized bed assembly, enabling heat exchange of solid particles in a fluidized state, which significantly improves heat exchange efficiency and helps enhance the system's responsiveness. A hot storage tank 8 connects the heating unit and the heat exchange unit, providing temporary storage for high-temperature solid particles. A cold storage tank 13 and a cold material buffer silo 1 are located between the heat exchange unit and the heating unit, providing temporary storage for low-temperature solid particles. The low-temperature solid particles are transported from the cold storage tank 13 to the cold material buffer silo 1 by a particle elevator 14. The cold material buffer silo 1 is positioned high above the heating unit, allowing the low-temperature solid particles inside to enter the heating unit under gravity. This process eliminates the need for mechanical assistance, reducing response lag caused by control delays, mechanical failures, or energy transfer issues, thus enabling rapid response and rapid adjustment of the power load to adapt to rapidly changing load conditions. Simultaneously, the cold material buffer silo 1 provides temporary storage for the low-temperature solid particles, acting as a buffer to ensure the smooth operation of the particle conveyor 14 and prevent the impact of frequent load changes on the equipment.

[0024] According to the solid particle thermal storage system of this application, by arranging a cold material buffer silo 1 at a high level, the material circulation of the solid particle thermal storage system is decomposed into two independent processes: "stable lifting" and "rapid response." A combination of gravity flow regulation and mechanical flow stabilization is used to achieve rapid load regulation while ensuring stable system operation. The regulation function of the high-level buffer silo protects critical conveying equipment from the impact of frequent load fluctuations. This application achieves a second-level rapid response through gravity flow regulation, solving the problem of slow response speed caused by the large inertia of mechanical conveying equipment in traditional thermal storage systems. Simultaneously, by stabilizing the operation of the mechanical conveying equipment, equipment wear is significantly reduced, and equipment service life is extended. It also has advantages such as simple control, reliable operation, and low maintenance costs, effectively improving the practical value and economy of the thermal storage system in power grid frequency regulation.

[0025] According to some embodiments of this application, the heat storage tank 8 is disposed above the heat exchange unit, and the high-temperature solid particles in the heat storage tank 8 are adapted to enter the heat exchange unit under the action of gravity. In this embodiment, the heat storage tank 8 is disposed above the heat exchange unit, and the high-temperature solid particles inside it are adapted to enter the heat exchange unit under the action of gravity. This process does not require mechanical equipment to assist in transportation, reducing response lag caused by control delays, mechanical failures, energy transfer, etc., thereby enabling rapid response and rapid adjustment of power load to adapt to rapidly changing load conditions.

[0026] The above embodiments, combined with the high-level cold material buffer silo 1, enable rapid response in the heat storage and heat exchange process, thereby achieving efficient and stable regulation of the power grid during rapid load changes.

[0027] According to some embodiments of this application, control valves are provided at the outlets of the cold material buffer bin 1, the hot storage tank 8, and the cold storage tank 13. These control valves are adapted to adjust their opening degree to control the flow rate of solid particles. In this embodiment, by setting multiple corresponding control valves, the opening degree of the outlets of the cold material buffer bin 1, the hot storage tank 8, and the cold storage tank 13 can be adjusted respectively, thereby controlling the flow rate of solid particles entering the heating unit or heat exchange unit, and thus controlling the efficiency of heat storage and release. Furthermore, this embodiment can achieve grid load regulation by adjusting the flow rate of solid particles.

[0028] like Figure 1 As shown, in some embodiments, a first valve 15 is provided at the outlet of the cold material buffer bin 1. The first valve 15 can control the flow rate of low-temperature solid particles into the heating unit. Combined with the adjustment of the heating efficiency of the heating unit, load regulation of the power grid can be achieved. A second valve 16 is provided at the outlet of each of the hot storage tanks 8. The second valve 16 can control the flow rate of high-temperature solid particles into the heat exchange unit. Load regulation of the power grid can be achieved by controlling the steam heating efficiency. A third valve 17 is provided at the outlet of the cold storage tank 13. The third valve 17 can control the flow rate of low-temperature solid particles conveyed to the cold material buffer bin 1. Combined with the working efficiency of the particle elevator 14 and the outflow rate of low-temperature solid particles in the cold material buffer bin 1, the inflow and outflow rates of low-temperature solid particles in the cold material buffer bin 1 can be adjusted to ensure that the flow rate of low-temperature solid particles matches the load demand of the power grid, while ensuring the stable operation and power regulation of the particle elevator 14. This embodiment achieves a power response within seconds by rapidly adjusting the flow rate of gravity-fed solid particles through the first valve 15, while simultaneously ensuring the stable operation of the particle elevator 14 and the third valve 17. This effectively solves the technical challenge of balancing response speed and equipment lifespan in traditional thermal storage systems. Furthermore, it can be flexibly applied to thermal storage scenarios of various scales, and is of great value in improving the grid frequency regulation capability and promoting the consumption of renewable energy.

[0029] According to some embodiments of this application, the heating unit includes a fluidized bed electric heater 2 and a fluidizing gas pipeline 3. The fluidized bed electric heater 2 is connected to a cold material buffer bin 1 and a heat storage tank 8. Multiple fluidizing gas inlets are formed at the bottom of the fluidized bed electric heater 2. The fluidizing gas pipeline 3 is connected to the multiple fluidizing gas inlets to facilitate the introduction of fluidizing gas 6 into the fluidized bed electric heater 2. The fluidizing gas 6 can be cold air, etc. In this embodiment, the fluidized bed electric heater 2 is a specific form of the aforementioned fluidized bed assembly. By setting the fluidized bed electric heater 2, the fluidizing gas 6 introduced through the multiple fluidizing gas inlets can be used to maintain the low-temperature solid particles in a fluidized state and heat them to obtain high-temperature solid particles, thereby achieving heat storage. This embodiment uses the fluidized bed electric heater 2 to heat the solid particles and store heat, which can promote uniform heating of the solid particles, improve heat transfer efficiency, and thus improve heat storage efficiency.

[0030] Among them, the fluidized bed electric heater 2 is connected to the power grid system and uses electricity to heat solid particles, thereby increasing the power grid operating load and using the heat storage process to achieve power grid load regulation.

[0031] According to some embodiments of this application, the heating unit further includes a hot gas pipeline 4 and a preheater 5. The hot gas pipeline 4 is connected to the fluidized bed electric heater 2 to facilitate the output of high-temperature gas 7 from the fluidized bed electric heater 2. The fluidizing gas pipeline 3 and the hot gas pipeline 4 are connected to the preheater 5 to facilitate heat exchange between the high-temperature gas 7 and the fluidizing gas 6 in the preheater 5, thereby preheating the fluidizing gas 6. When the fluidized bed electric heater 2 is running, it simultaneously heats the low-temperature solid particles and the fluidizing gas 6 to obtain high-temperature solid particles and high-temperature gas 7 (high-temperature flue gas). In this embodiment, by setting the preheater 5, the high-temperature gas 7 obtained in the fluidized bed electric heater 2 can be used to preheat the fluidizing gas 6, so that the heat in the high-temperature gas 7 can be effectively utilized. At the same time, after the preheated fluidizing gas 6 enters the fluidized bed electric heater 2, it can play a certain role in heat exchange during the fluidization of the low-temperature solid particles, thereby raising the temperature of the low-temperature solid particles and reducing the energy consumption of the fluidized bed electric heater 2.

[0032] According to some embodiments of this application, the fluidized bed electric heater 2 is internally provided with multiple heating components arranged at intervals. In this embodiment, by providing multiple heating components, the low-temperature solid particles are heated, causing them to rise in temperature under the fluidization effect of the fluidizing gas 6, thereby obtaining high-temperature solid particles. The multiple heating components arranged at intervals can improve the uniformity and efficiency of heating. Furthermore, the heating components can be selected from electric heating wires, etc.

[0033] According to some embodiments of this application, the heat exchange unit includes a heat exchanger 9 and a heat exchange pipeline 10. A heat exchange cavity is formed inside the heat exchanger 9, connecting a hot storage tank 8 and a cold storage tank 13. A portion of the heat exchange pipeline 10 is disposed within the heat exchange cavity. One end of the heat exchange pipeline 10 extends outside the heat exchanger 9 and forms a cold steam inlet, while the other end extends outside the heat exchanger 9 and forms a hot steam outlet. In this embodiment, the heat exchange cavity in the heat exchanger 9 provides a heat exchange space. High-temperature solid particles from the hot storage tank 8 enter the heat exchange cavity and contact the outer wall of the heat exchange pipeline 10. Cold steam 11 enters the heat exchange pipeline 10 through the cold steam inlet. In the portion of the heat exchange pipeline 10 located inside the heat exchanger 9, heat exchange occurs between the heat exchange pipeline 10 and the high-temperature solid particles through the pipe wall of the heat exchange pipeline 10. The heated hot steam 12 flows out through the hot steam outlet. After heat exchange, the high-temperature solid particles become low-temperature solid particles, thereby achieving heat release.

[0034] The cold steam inlet and hot steam outlet can be connected to the thermal system (such as the main steam system). The steam heating process of the thermal system requires electric heating. By providing part of the heat energy for steam heating to the thermal system through the solid thermal storage system, the need for electric heating can be reduced, thereby reducing the load on the power grid.

[0035] According to some embodiments of this application, the diameter of the portion of the wall connecting to the outlet of the cold material buffer bin 1, the hot storage tank 8, and / or the cold storage tank 13 gradually decreases along the flow direction of the solid particles. In this embodiment, the diameter of the portion of the wall connecting to the outlet gradually decreases along the flow direction of the solid particles, and when it decreases to the outlet diameter, it connects precisely to the outlet. This allows the solid particles to flow out of the outlet more smoothly, promotes the flow of solid particles, optimizes flow efficiency, and avoids blockage and residue.

[0036] According to some embodiments of this application, the solid particles are selected from one or more of sand, quartz sand, ceramic particles, and silicon carbide particles. In this embodiment, sand, quartz sand, ceramic particles, and silicon carbide particles can maintain stable physical and chemical properties at high temperatures of 800-1000℃. Using the above-mentioned materials as solid particles allows for efficient and stable heat storage and release cycling.

[0037] According to some embodiments of this application, the cold material buffer silo 1, heating unit, hot storage tank 8, heat exchange unit, and cold storage tank 13 are arranged sequentially from high to low along the height direction. In this embodiment, the sequential arrangement of the cold material buffer silo 1, heating unit, hot storage tank 8, heat exchange unit, and cold storage tank 13 along the height direction allows the processes of low-temperature solid particles entering the heating unit, high-temperature solid particles entering the hot storage tank 8, high-temperature solid particles entering the heat exchange unit, and low-temperature solid particles entering the cold storage tank 13 to all be completed under the action of gravity, which can improve flow efficiency and thus improve heat storage and release efficiency, thereby further enhancing the responsiveness to the power grid and main steam system.

[0038] In one specific embodiment of this application, the working process of the solid particle thermal storage system is as follows: During periods of low grid load or off-peak electricity pricing, the system initiates the thermal energy storage process. Specifically, firstly, the third valve 17 opens to a predetermined degree, allowing low-temperature solid particles to be discharged from the cold storage tank 13. These particles are then stably transported via the particle elevator 14 to the cold material buffer silo 1, located at the highest point of the system, for temporary storage. Simultaneously, the first valve 15 opens to the corresponding degree according to the thermal energy storage requirements, allowing the low-temperature solid particles in the cold material buffer silo 1 to flow smoothly into the fluidized bed electric heater 2 below under gravity. In the fluidized bed electric heater 2, the low-temperature solid particles are thoroughly mixed with the hot air preheated by the preheater 5 and electrically heated to the design operating temperature of 800-1000℃. The heated high-temperature solid particles are discharged from the lower outlet of the fluidized bed electric heater 2 into the thermal storage tank 8 for storage, completing the thermal energy storage process. Meanwhile, the high-temperature flue gas generated by heat exchange is discharged from the upper outlet of the fluidized bed electric heater 2 and enters the preheater 5 to recover waste heat, which is used to preheat the cold air entering the fluidized bed electric heater 2.

[0039] During periods of high grid load demand or peak electricity prices, the system switches to a heat release process. Specifically, the second valve 16 opens to the required degree as needed, and the high-temperature solid particles flow into the particle-steam heat exchanger 9 under gravity. Inside the heat exchanger 9, the high-temperature solid particles transfer heat to the cold steam 11 supplied by the system, heating it to the required parameters of hot steam 12. This hot steam 12 can be returned to the main steam system for use, while the low-temperature solid particles, after releasing heat, are discharged from the outlet below the heat exchanger 9 into the cold storage tank 13, completing the heat release process.

[0040] The above-described heat storage and heat release processes together form a complete heat storage and release cycle.

[0041] Furthermore, during steady-state operation, all equipment coordinates to maintain stable operation. The first valve 15 and the third valve 17 maintain a fixed opening degree matching the steady-state load, and the particle elevator 14 operates at a constant rate to ensure the system is in optimal working condition. The fluidized bed electric heater 2 maintains a stable heating power according to the set temperature requirements, and the preheater 5 continuously preheats the cold air entering the system to improve overall system efficiency.

[0042] When the power grid experiences rapid load fluctuations, the system achieves a rapid response through a dual-loop design. Specifically, in the system's heat storage stage, the system prioritizes adjusting the opening of the first valve 15, thereby rapidly regulating the power output by altering the flow rate of particles flowing into the fluidized bed electric heater 2 by gravity. This adjustment process is entirely driven by gravity, resulting in a rapid response and strong load-change capability. Simultaneously, the particle elevator 14 and the third valve 17 are adjusted slowly to ensure a smooth flow of particles transported from the cold storage tank 13 to the high-level cold material buffer silo 1, protecting the mechanical equipment from the impact of frequent load fluctuations. In the system's heat release stage, the flow rate of high-temperature particles entering the particle-steam heat exchanger 9 is regulated by controlling the opening of the second valve 16, thereby controlling the output steam parameters.

[0043] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0045] In the description of this application, "multiple" means two or more.

[0046] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them.

[0047] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0048] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A solid particle thermal storage system based on a fluidized bed, characterized in that, include: A cold material buffer bin, which is suitable for storing low-temperature solid particles; A heating unit is connected to the cold material buffer bin, and the low-temperature solid particles are adapted to exchange heat and rise in the heating unit. A thermal storage tank, which is connected to the heating unit, is adapted to store high-temperature solid particles from the heating unit; A heat exchange unit is connected to the heat storage tank, and the high-temperature solid particles are adapted to exchange heat and cool down in the heat exchange unit. A cold storage tank, connected to the heat exchange unit, is adapted to store low-temperature solid particles from the heat exchange unit; wherein, The cold material buffer bin is located above the heating unit; a particle elevator is provided between the cold material buffer bin and the cold storage tank, and the particle elevator is adapted to transport the low-temperature solid particles from the cold storage tank to the cold material buffer bin; the low-temperature solid particles in the cold material buffer bin are adapted to enter the heating unit under the action of gravity; The heating unit and / or the heat exchange unit includes a fluidized bed assembly adapted for heat exchange of solid particles in a fluidized state.

2. The fluidized bed-based solid particle thermal storage system according to claim 1, characterized in that, The heat storage tank is positioned above the heat exchange unit, and the high-temperature solid particles in the heat storage tank are adapted to enter the heat exchange unit under the influence of gravity.

3. The fluidized bed-based solid particle thermal storage system according to claim 2, characterized in that, The cold material buffer silo, the hot storage tank, and the cold storage tank are all equipped with control valves at their outlets. These control valves are adapted to adjust their opening degree to control the flow rate of the solid particles.

4. The fluidized bed-based solid particle thermal storage system according to claim 1, characterized in that, The heating unit includes: A fluidized bed electric heater, which is connected to the cold material buffer bin and the hot storage tank, has multiple fluidizing gas inlets at its bottom; A fluidizing gas pipeline, which connects to the plurality of fluidizing gas inlets, is adapted to introduce fluidizing gas into the fluidized bed electric heater.

5. The fluidized bed-based solid particle thermal storage system according to claim 4, characterized in that, The heating unit also includes: A hot gas pipeline, which is connected to the fluidized bed electric heater, is adapted to output high-temperature gas from the fluidized bed electric heater; A preheater, wherein the fluidizing gas pipeline and the hot gas pipeline are connected to the preheater to facilitate heat exchange between the high-temperature gas and the fluidizing gas in the preheater, thereby preheating the fluidizing gas.

6. The fluidized bed-based solid particle thermal storage system according to claim 4, characterized in that, The fluidized bed electric heater has multiple heating components spaced apart inside.

7. The fluidized bed-based solid particle thermal storage system according to claim 1, characterized in that, The heat exchange unit includes: A heat exchanger having a heat exchange cavity inside, the heat exchange cavity being connected to the hot storage tank and the cold storage tank; A heat exchange pipeline is provided in the heat exchange chamber. One end of the heat exchange pipeline extends to the outside of the heat exchanger and forms a cold steam inlet, and the other end of the heat exchange pipeline extends to the outside of the heat exchanger and forms a hot steam outlet.

8. The fluidized bed-based solid particle thermal storage system according to claim 3, characterized in that, The diameter of the portion of the wall of the cold material buffer silo, the hot storage tank, and / or the cold storage tank connected to the outlet gradually decreases along the flow direction of the solid particles.

9. The fluidized bed-based solid particle thermal storage system according to claim 1, characterized in that, The solid particles are selected from one or more of sand, quartz sand, ceramic particles, and silicon carbide particles.

10. The fluidized bed-based solid particle thermal storage system according to claim 1, characterized in that, The cold material buffer bin, the heating unit, the hot storage tank, the heat exchange unit, and the cold storage tank are arranged in descending order of height.

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