A fluidized bed energy storage system and heat storage and release method

Abstract

An embodiment of the present invention provides a fluidized bed energy storage system and a heat storage and release method. The fluidized bed energy storage system includes an energy supply unit, a fixed bed heat storage unit, a fluidized bed heat storage and release unit, a steam application unit and a circulation pipeline. The circulation pipeline circulates and connects the energy supply unit, the fixed bed heat storage unit and the fluidized bed heat storage and release unit in sequence. A fluid working medium circulates in the circulation pipeline. The fixed bed heat storage unit includes a fixed bed and first particles filled in the fixed bed for heat exchange with the fluid working medium. The fluidized bed heat storage and release unit includes a fluidized bed, second particles filled in the fluidized bed for heat exchange with the fluid working medium, and a heat extraction pipe buried in the second particles. The inlet of the heat extraction pipe is used for water flow; the outlet of the heat extraction pipe is connected to the steam application unit, and the fixed bed in front of the fluidized bed can ensure the stability of the fluid working medium input into the fluidized bed, thereby ensuring the stability of the steam application process.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a fluidized bed energy storage system and a heat storage and release method. Background Art

[0002] Currently, renewable energy is widely used, for example, in steam generation, heating, and hot water supply based on solar energy. However, a major drawback of renewable energy is its intermittency and instability. For example, solar energy can only be harvested during the day, and its availability varies depending on the time of day and the situation.

[0003] In order to realize the application of renewable energy, fluidized beds can be used for heat storage and release. However, due to the intermittent and unstable nature of renewable energy, the heat stored in the fluidized bed changes, which in turn leads to instability in heat release for power generation or other energy applications. Summary of the Invention

[0004] In view of the above problems, a fluidized bed energy storage system and a heat storage and release method are proposed to overcome the above problems or at least partially solve the above problems, including:

[0005] A fluidized bed energy storage system, comprising an energy supply unit, a fixed bed heat storage unit, a fluidized bed heat storage and release unit, a steam application unit, and a circulation pipeline, wherein the circulation pipeline cyclically connects the energy supply unit, the fixed bed heat storage unit, and the fluidized bed heat storage and release unit in sequence, and a fluid working medium circulates through the circulation pipeline. The fixed bed heat storage unit comprises a fixed bed and first particles filled in the fixed bed for exchanging heat with the fluid working medium. The fluidized bed heat storage and release unit comprises a fluidized bed, second particles filled in the fluidized bed for exchanging heat with the fluid working medium, and a heat extraction pipe embedded in the second particles. The inlet of the heat extraction pipe is used for passing water; the outlet of the heat extraction pipe is connected to the steam application unit.

[0006] The energy supply unit is used to collect energy and use the energy to heat the fluid working medium in the circulation pipeline, and transport the heated fluid working medium to the fixed bed heat storage unit through the circulation pipeline;

[0007] The fixed bed heat storage unit is used to perform heat exchange processing between the first particles and the fluid working medium in the fixed bed, and to transport the fluid working medium to the fluidized bed heat storage and release unit through the circulation pipeline;

[0008] The fluidized bed heat storage and release unit is used to use the second particles to exchange heat with the fluid working medium in the fluidized bed during the heat storage stage, and output the fluid working medium after heat exchange to the energy supply unit through the circulation pipeline for heating; in the heat release stage, the second particles are used to store heat energy stored in the fluidized bed by heat exchange with the fluid working medium to heat the water entering the heat extraction pipeline to generate steam, and the steam is transported to the steam application unit.

[0009] Optionally, a circulation pump is provided on the circulation pipeline between the fluidized bed heat storage and release unit and the energy supply unit, and the circulation pump is used to control the fluid working medium in the circulation pipeline to circulate along a preset circulation path when it is turned on.

[0010] Optionally, the first particles are encapsulated phase change material particles, the second particles are high temperature resistant solid particles, and the size of the first particles is larger than that of the second particles.

[0011] Optionally, the first particles are spherical particles with a particle size ranging from 10 mm to 50 mm, and the second particles are particles with a particle size ranging from 0 μm to 200 μm.

[0012] Optionally, the working range of the first particles is 200°C to 600°C.

[0013] Optionally, the fluidized bed heat storage and release unit further includes a gas inlet and a gas outlet. The fluidized bed heat storage and release unit is used to introduce gas into the fluidized bed from the gas inlet during the heat release stage, and the second particles are heated by the gas and the water in the heat absorption pipe to generate steam. During the heat storage stage, the gas supply to the fluidized bed is stopped.

[0014] Optionally, the gas velocity when passing gas through the fluidized bed is 2 to 10 times the minimum fluidization velocity of the second particles.

[0015] Optionally, the specific heat capacity of the fluid working medium is greater than 2000 J / (kg·°C).

[0016] Optionally, the fluidized bed is an adiabatic fluidized bed, and the shell of the fluidized bed is wrapped with an insulation layer.

[0017] A heat storage and release method based on a fluidized bed heat storage system is applied to the fluidized bed energy storage system as described above, the method comprising:

[0018] The energy supply unit is used to collect energy, and the energy is used to heat the fluid working medium in the circulation pipeline, and the heated fluid working medium is transported to the fixed bed of the fixed bed heat storage unit through the circulation pipeline;

[0019] After the first particles in the fixed bed are subjected to heat exchange treatment with the fluid working medium, the fluid working medium is transported to the fluidized bed of the fluidized bed heat storage and release unit through the circulation pipeline;

[0020] When the fluidized bed heat storage and release unit is in the heat storage stage, the fluid working medium and the second particles are heat-exchanged in the fluidized bed, and the fluid working medium after heat exchange is transported to the energy supply unit for heating;

[0021] When the fluidized bed heat storage and release unit is in the heat release stage, the heat energy stored by the second particles and the fluid working medium in the fluidized bed is used to heat the water entering the heat extraction pipeline to generate steam, and the steam is transported to the steam application unit.

[0022] The embodiments of the present invention have the following advantages:

[0023] By providing a fixed bed heat storage unit and a fluidized bed heat storage and release unit within a fluidized bed energy storage system, the present invention employs a method whereby the first particles in the fixed bed undergo a preliminary heat exchange with a fluid working medium heated by an energy source, the fluid working medium with excess heat is then transported to the fluidized bed for heat exchange, and the fluidized bed then releases heat before steam is applied via the steam application unit. Thus, in the present invention, the presence of a fixed bed in front of the fluidized bed ensures the stability of the fluid working medium input to the fluidized bed. Even if the collected energy source is intermittent or unstable, the fluidized bed can achieve stable heat storage and release, thereby ensuring the stability of the steam application process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the description of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1a A fluidized bed energy storage system is provided in one embodiment of the present invention;

[0026] Figure 1b A fluidized bed energy storage system including a tower-type solar thermal unit is provided in one embodiment of the present invention;

[0027] Figure 1c A fluidized bed energy storage system comprising a trough-type solar thermal unit is provided in one embodiment of the present invention.

[0028] Figure 2 This is a flow chart of the steps of a heat storage and release method based on a fluidized bed heat storage system provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0029] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0030] Reference Figure 1a , shows a fluidized bed energy storage system provided by an embodiment of the present invention. The fluidized bed energy storage system 100 includes an energy supply unit 101, a fixed bed heat storage unit 102, a fluidized bed heat storage and release unit 103, a steam application unit 104 and a circulation pipe 105. The circulation pipe circulates and connects the energy supply unit 101, the fixed bed heat storage unit 102 and the fluidized bed heat storage and release unit 103 in sequence.

[0031] In the embodiment of the present invention, the circulation connection of the circulation pipeline can be specifically as follows: the fluid working medium outlet end of the energy supply unit 101 is connected to the fluid working medium inlet end of the fixed bed heat storage unit 102 through the circulation pipeline 105, the fluid working medium outlet end of the fixed bed heat storage unit 102 is connected to the fluid working medium inlet end of the fluidized bed heat storage and release unit 103 through the circulation pipeline 105, and the fluid working medium outlet end of the fluidized bed heat storage and release unit 103 is connected to the fluid working medium inlet end of the energy supply unit 101 through the circulation pipeline. Thus, the circulation pipeline realizes the circulation connection between the energy supply unit 101, the fixed bed heat storage unit 102, and the fluidized bed heat storage and release unit 103.

[0032] In the embodiments of the present invention, a fluid working medium circulates within the circulation pipe. This fluid working medium may have a high specific heat capacity. The fluid working medium within the circulation pipe remains in a flowing liquid state and, due to its high specific heat capacity, enables efficient heat exchange with the fixed-bed heat storage unit and the fluidized-bed heat storage and release unit. Specifically, the specific heat capacity of the fluid working medium between the fixed-bed heat storage unit and the energy supply unit is greater than 2000 J / (kg·°C). The fluid working medium may include, but is not limited to, binary molten salt or thermal oil.

[0033] The fixed-bed heat storage unit in an embodiment of the present invention includes a fixed bed and first particles filled within the fixed bed to exchange heat with a fluid working medium. The first particles within the fixed bed store heat through heat exchange with the fluid working medium. The fluid working medium is introduced into the fixed bed, where it exchanges and stores heat. The temperature within the fixed bed decreases from top to bottom, thereby controlling the fluid working medium's temperature within a certain range and delivering a stable fluid working medium.

[0034] In one example, the first particles can be encapsulated phase change material particles to fully contact the fluid within the fixed bed to achieve heat exchange and improve heat exchange efficiency. The phase change material can be a molten salt phase change material, which has advantages such as small size, high energy storage density, and a wide phase change temperature range. The encapsulation material of the phase change material can be set based on the selected phase change material properties and the operating scenario, and is not limited in this embodiment of the present invention.

[0035] Phase change materials have problems such as corrosion of containers and high costs. By encapsulating phase change materials, problems such as phase segregation, liquid phase leakage, and corrosion of phase change materials can be significantly improved.

[0036] In one embodiment of the present invention, the first particles in the stationary phase are in direct contact with the fluid. The first particles may be spherical particles with a particle size ranging from 10 mm to 50 mm, for example, the particle size may be 10 mm, 20 mm, 40 mm, or 50 mm. The large spherical shape allows for a large contact area between the particles and the fluid, facilitating sufficient heat exchange.

[0037] In one embodiment of the present invention, the first particles may be high temperature phase change materials, and the operating range of the high temperature phase change materials is 200°C to 600°C. For example, the operating temperature may be 200°C, 200°C, 600°C,

[0038] The fluidized bed heat storage and release unit in the embodiment of the present invention includes a fluidized bed, second particles filled in the fluidized bed for heat exchange with the fluid working medium, and a heat extraction pipe buried in the second particles. The inlet of the heat extraction pipe is used for water flow; the outlet of the heat extraction pipe is connected to the steam application unit.

[0039] In one embodiment of the present invention, the second particles may be high-temperature resistant solid particles, such as high-temperature ceramic particles, quartz sand particles, etc. The first particles are larger than the second particles. Specifically, the second particles have a particle size ranging from 0 μm to 200 μm, such as 50 μm, 100 μm, or 200 μm.

[0040] In the embodiment of the present invention, the functions of the various parts of the fluidized bed energy storage system are as follows:

[0041] The energy supply unit is used to collect energy, use the energy to heat the fluid in the circulation pipeline, and then transport the heated fluid through the circulation pipeline to the fixed-bed thermal storage unit. The energy source is the energy to be collected, and can specifically include, but is not limited to, any one or more of solar energy, wind energy, valley electricity, and other energy sources.

[0042] The fixed bed heat storage unit is used to perform heat exchange processing with the first particles and the fluid working medium in the fixed bed, and transport the fluid working medium to the fluidized bed heat storage and release unit through a circulation pipeline;

[0043] In practical applications, after the heated fluid enters the fixed bed of the fixed bed heat storage unit, it fully contacts and exchanges heat with the first particles, transferring part of the heat taken out from the energy source to the first particles in the fixed bed. After part of the heat is transferred, the temperature of the heated fluid is reduced to a certain range, and the fixed phase can be output, and the fluid carrying excess heat is transported to the fluidized bed heat storage and release unit through a circulation pipeline.

[0044] The fluidized bed heat storage and release unit is used to use the second particles to exchange heat with the fluid working medium in the fluidized bed during the heat storage stage, and output the fluid working medium after heat exchange to the energy supply unit through a circulation pipeline for heating; in the heat release stage, the second particles are used to exchange heat with the fluid working medium in the fluidized bed to store heat energy to heat the water entering the heat extraction pipeline to generate steam, and the steam is transported to the steam application unit.

[0045] In practical applications, a portion of the circulating pipe is located within the fluidized bed heat storage and release unit 103. Specifically, this portion of the pipe can be configured as a serpentine bend to achieve efficient heat storage within the fluid bed. During the heat storage phase, the fluidized bed acts like a fixed bed, exchanging heat with the fluid to store energy. During the heat release phase, the second particles fluidize and release heat.

[0046] Specifically, during the heat storage phase, a fluid is fed into the fluidized bed heat storage and release unit's internal pipes, exchanging heat with the second particles without direct contact. Heat from the fluid is transferred to the second particles in the fluidized bed, achieving heat storage. After heat storage is complete, the fluid is transported to the energy supply unit, completing the cycle of heat storage.

[0047] In the heat release stage, water flows through the inlet of the heat extraction pipe, the second particles are fluidized, and the water in the heat extraction pipe is heated to generate steam, which is then output from the outlet of the heat extraction pipe to the connected steam application unit, thereby realizing the application of steam in the steam application unit.

[0048] In embodiments of the present invention, the steam application unit can be a steam power generation device that generates electricity using steam to output electrical energy. Alternatively, the steam application unit can be a heating device, where the generated steam is delivered to a heating pipe via an evaporator for heating. Furthermore, water in a heat extraction pipe can be directly heated to generate hot water for direct use.

[0049] In one embodiment of the present invention, a circulating pump is provided on the circulation pipe between the fluidized bed heat storage and release unit and the energy supply unit. When the circulating pump is turned on, it controls the flow of the fluid in the circulation pipe along a predetermined circulation path. The provision of the circulating pump allows for control of the fluid flow rate and improves heat exchange efficiency.

[0050] In one embodiment of the present invention, the fluidized bed heat storage and release unit further includes a gas inlet and a gas outlet. During the heat release phase, gas is introduced into the fluidized bed through the gas inlet. The second particles are heated by the gas and water in the heat absorption pipe, generating steam. During the heat storage phase, the gas supply to the fluidized bed is stopped. By introducing gas into the fluidized bed during heat release, the output thermal power can be increased.

[0051] The gas may be air or other thermally stable gas that does not chemically react with the second particles.

[0052] In one embodiment of the present invention, the gas velocity when passing gas through the fluidized bed is 2 to 10 times the minimum fluidization velocity of the second particles. By controlling the gas velocity, the heat release efficiency of the fluidized bed can be precisely controlled.

[0053] In one embodiment of the present invention, the fluidized bed is an adiabatic fluidized bed, and the shell of the fluidized bed is wrapped with an insulation layer. The provision of the adiabatic fluidized bed and the insulation layer prevents heat exchange between the fluidized bed and the outside, ensuring efficient heat storage and heat release efficiency of the fluidized bed.

[0054] The following uses solar power generation as an example to illustrate how to implement solar power generation using the technical solution in the embodiment of the present invention:

[0055] Solar energy, as a renewable energy source, has many applications in China, such as steam generation / heating, and hot water supply. However, a major drawback of solar energy is its intermittency and instability. To address this, most regions utilizing solar energy require energy storage systems. There are different types of energy storage solutions. One of the most important applications of solar energy is power generation, and the most suitable energy storage system generally depends on the type of technology used for power generation. For solar power generation, there are two options: photovoltaic (PV) and concentrated thermal (CSP).

[0056] Compared with photovoltaic power generation, solar thermal power generation technology has the advantages of simple principle, large scale, easy energy storage, small fluctuation, long life, and less energy consumption and pollution in the manufacturing process.

[0057] The use of fluidized bed equipment in CSP technology improves the efficiency of heat absorption and release. However, the particles in the fluidized bed store heat as sensible heat, resulting in low power density. Furthermore, the continuous temperature decay during the heat release process can lead to unstable heat output. Furthermore, in actual industrial applications, photovoltaic power generation is significantly affected by solar radiation resources, resulting in fluctuating and intermittent output power.

[0058] In the embodiments of the present invention, solar power generation utilizes CSP technology. The heat storage unit incorporated into CSP technology is an effective method for improving heat storage and release stability, ensuring stable power generation. Specifically, molten salt phase change materials (PCMs) can be used to achieve this. These materials offer advantages such as compact size, high energy storage density, and a wide phase change temperature range.

[0059] In the fluidized bed heat storage system of solar thermal power generation, a fixed bed and a fluidized bed can be set up. The fixed bed performs preliminary heat storage, and the fluidized bed stores the excess heat of the fluid working medium. When power generation is needed, water is passed through to generate steam for steam power generation.

[0060] In solar thermal power generation technology, the energy supply unit may be a solar thermal unit, which may be a tower solar thermal unit or a trough solar thermal unit.

[0061] Among them, the tower-type solar thermal unit includes a collector plate (such as a heliostat), a heat absorber, and a solar thermal tower; the collector plate focuses sunlight and reflects it onto the heat absorber of the solar thermal tower, completing the conversion of light energy into heat energy, heating the fluid flowing through the heat absorber, and the fluid carries heat into the fixed bed storage unit.

[0062] The trough-type solar thermal unit includes a heat collecting trough and a heat absorbing pipeline; the heat collecting trough focuses sunlight and reflects it onto the heat absorbing pipeline arranged in the heat collecting trough. After the fluid flowing through the heat absorbing pipeline is heated, it carries heat and flows into the fixed bed storage unit.

[0063] like Figure 1b The figure shows a fluidized bed energy storage system with a tower-type solar thermal unit. The working fluid can be a binary molten salt mixture of sodium nitrate and potassium nitrate. The solar collector focuses sunlight and reflects it onto the tower's heat absorber, converting the light energy into heat. The absorber then heats the binary molten salt, which then flows into a fixed bed carrying the heat. The fixed bed is filled with spherical phase change material particles ranging in size from 10 to 50 mm. The fluidized bed is filled with sand, which has a particle size range of 50-200 μm, for heat storage and transfer. The heat extraction tube bundle in the fluidized bed is in the form of a serpentine tube. As the sand fluidizes, it transfers heat to the heat extraction tube bundle, which in turn heats the water in the heat extraction tube bundle into steam. The steam pressure is 4 MPa and the temperature is 250°C. The steam is then fed into a steam turbine generator set for steam power generation.

[0064] During the fluidized bed's heat storage phase, the air inlet valve corresponding to the blower is closed, and the cold water inlet valve corresponding to the cold water pump is closed. During the fluidized bed's heat release phase, the air inlet valve for the blower and the cold water inlet valve for the cold water pump are opened, allowing water and air to flow. The air fluidizes the sand, transferring heat to the heat-absorbing tube bundle, heating the cold water in the heat-extracting tube bundle and generating steam.

[0065] like Figure 1c The figure shows a fluidized bed energy storage system that includes a trough-type solar thermal unit. The fluid can be thermal oil. The solar trough focuses sunlight and reflects it onto a heat-absorbing pipe arranged within the trough. The hot fluid in the heat-absorbing pipe is heated and then flows into the fixed bed, carrying the heat. The fixed bed is filled with spherical phase change material particles with a particle size range of 20-40 mm. The fluidized bed is filled with sand for heat storage and transfer, with a particle size range of 50-150 μm. The heat extraction tube bundles in the fluidized bed are in the form of serpentine tubes. When the sand fluidizes, it transfers heat to the heat extraction tube bundles, which in turn heats the water in the heat extraction tube bundles into steam. The steam is then fed into a steam turbine generator set for steam power generation.

[0066] In an embodiment of the present invention, the fixed bed placed in front of the fluidized bed can ensure the stability of the fluid working medium input into the fluidized bed. Even if the collected energy has problems such as intermittency and instability, the fluidized bed can achieve stable heat storage and heat release, thereby ensuring the stability of the steam application process.

[0067] Reference Figure 2 , showing a flow chart of the steps of a heat storage and release method based on a fluidized bed heat storage system provided by an embodiment of the present invention, wherein the fluidized bed energy storage system includes an energy supply unit, a fixed bed heat storage unit, a fluidized bed heat storage and release unit, a steam application unit and a circulation pipeline, the circulation pipeline circulates the energy supply unit, the fixed bed heat storage unit and the fluidized bed heat storage and release unit in sequence, a fluid working medium circulates in the circulation pipeline, the fixed bed heat storage unit includes a fixed bed and first particles filled in the fixed bed for heat exchange with the fluid working medium, the fluidized bed heat storage and release unit includes a fluidized bed, second particles filled in the fluidized bed for heat exchange with the fluid working medium, and a heat extraction pipe embedded in the second particles, the inlet of the heat extraction pipe is used for water; the outlet of the heat extraction pipe is connected to the steam application unit;

[0068] The energy supply unit is used to collect energy and use the energy to heat the fluid working medium in the circulation pipeline, and transport the heated fluid working medium to the fixed bed heat storage unit through the circulation pipeline;

[0069] The fixed bed heat storage unit is used to perform heat exchange processing with the first particles and the fluid working medium in the fixed bed, and transport the fluid working medium to the fluidized bed heat storage and release unit through a circulation pipeline;

[0070] The fluidized bed heat storage and release unit is used to use the second particles to exchange heat with the fluid working medium in the fluidized bed during the heat storage stage, and output the fluid working medium after heat exchange to the energy supply unit through a circulation pipeline for heating; in the heat release stage, the second particles are used to exchange heat with the fluid working medium in the fluidized bed to store heat energy to heat the water entering the heat extraction pipeline to generate steam, and the steam is transported to the steam application unit.

[0071] The fluidized bed energy storage system based on the above-mentioned fluidized bed energy storage system may specifically include the following steps:

[0072] Step 201: using an energy supply unit to collect energy, and using the energy to heat a fluid working medium in a circulation pipe, and transporting the heated fluid working medium to a fixed bed of a fixed bed heat storage unit through the circulation pipe;

[0073] In practical applications, the energy supply unit can collect energy, which can be any one or more of solar energy, wind energy, and off-peak electricity. The collected energy can be converted into heat energy to heat the fluid flowing through the energy supply unit. The fluid, carrying the heat energy, is then transported through a circulation pipeline to the fixed bed of the fixed-bed thermal storage unit for initial energy storage.

[0074] Step 202: After heat exchange between the first particles in the fixed bed and the fluid working medium, the fluid working medium is transported to the fluidized bed of the fluidized bed heat storage and release unit through a circulation pipeline;

[0075] The fixed bed can be filled with first particles. After the fluid working medium flows into the fixed bed, it can directly contact the first particles in the fixed bed to perform heat exchange treatment. Specifically, the fluid working medium can flow into the fixed bed from the upper part and out of the lower part, thereby achieving sufficient contact with the first particles. During the heat exchange process between the first particles and the fixed bed, the temperature in the fixed bed decreases from top to bottom. Therefore, after the fluid working medium exchanges heat, the temperature can be stabilized within a certain range, that is, the fixed bed has a certain temperature control effect.

[0076] The output fluid medium is made stable and controllable, and then the stable and controllable fluid medium is transported to the fluidized bed of the fluidized bed heat storage and release unit.

[0077] Step 203: When the fluidized bed heat storage and release unit is in the heat storage stage, the fluid working medium is heat-exchanged with the second particles in the fluidized bed, and the heat-exchanged fluid working medium is transported to the energy supply unit for heating;

[0078] The fluidized bed heat storage and release unit can both store and release heat.

[0079] During the heat storage stage, part of the circulating pipeline is located in the fluidized bed, and the outside of this part of the pipeline is filled with second particles. When the fluid working medium carries excess heat into the pipeline in the fluidized bed, heat is exchanged with the second particles through the pipeline, and the heat is stored in the second particles. That is, the second particles in the fluidized bed and the fluid working medium perform non-contact heat exchange.

[0080] After the fluid medium has been heat exchanged in the fluidized bed, it can be transported back to the energy supply unit through the circulation pipeline for a new round of heat storage. Thus, the entire system can achieve continuous heat storage and release.

[0081] Step 204: When the fluidized bed heat storage and release unit is in the heat release stage, the heat energy stored by the second particles and the fluid working medium in the fluidized bed is used to heat the water entering the heat extraction pipe to generate steam, which is then transported to the steam application unit.

[0082] During the heat release stage, the heat stored in the second particles during the fluidization time heats the water introduced into the heat extraction pipe to generate steam, which is then transported to the steam application unit.

[0083] In an embodiment of the present invention, the fixed bed placed in front of the fluidized bed can ensure the stability of the fluid working medium input into the fluidized bed. Even if the collected energy has problems such as intermittency and instability, the fluidized bed can achieve stable heat storage and heat release, thereby ensuring the stability of the steam application process.

[0084] It should be noted that for the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should be aware that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in this specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0085] An embodiment of the present invention further provides an electronic device, which may include a processor, a memory, and a computer program stored in the memory and capable of running on the processor. When the computer program is executed by the processor, the fluidized bed energy storage method as described above is implemented.

[0086] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the fluidized bed energy storage method as described above is implemented.

[0087] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0088] Those skilled in the art will appreciate that embodiments of the present invention may be provided as systems, methods, or computer program products. Thus, embodiments of the present invention may take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware. Furthermore, embodiments of the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0089] The embodiments of the present invention are described with reference to flowcharts and / or block diagrams of methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing terminal device produce a device for implementing the functions specified in one or more processes in the flowcharts and / or one or more blocks in the block diagrams.

[0090] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0091] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce computer-implemented processing, so that the instructions executed on the computer or other programmable terminal device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0092] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0093] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0094] The above is a detailed introduction to a fluidized bed energy storage system and a heat storage and release method provided. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A fluidized bed energy storage system, characterized in that: The fluidized bed energy storage system includes an energy supply unit, a fixed bed heat storage unit, a fluidized bed heat storage and release unit, a steam application unit, and a circulation pipeline. The circulation pipeline circulates the energy supply unit, the fixed bed heat storage unit, and the fluidized bed heat storage and release unit in sequence. A fluid working medium circulates in the circulation pipeline. The fixed bed heat storage unit includes a fixed bed and first particles filled in the fixed bed for exchanging heat with the fluid working medium. The fluidized bed heat storage and release unit includes a fluidized bed, second particles filled in the fluidized bed for exchanging heat with the fluid working medium, and a heat extraction pipe embedded in the second particles. The inlet of the heat extraction pipe is used for passing water; the outlet of the heat extraction pipe is connected to the steam application unit. The energy supply unit is used to collect energy and use the energy to heat the fluid working medium in the circulation pipeline, and transport the heated fluid working medium to the fixed bed heat storage unit through the circulation pipeline; The fixed bed heat storage unit is used to perform heat exchange processing between the first particles and the fluid working medium in the fixed bed, and to transport the fluid working medium to the fluidized bed heat storage and release unit through the circulation pipeline; The fluidized bed heat storage and release unit is used to, in a heat storage phase, use the second particles to exchange heat with the fluid working medium in the fluidized bed, and output the fluid working medium after heat exchange to the energy supply unit through the circulation pipeline for heating; in a heat release phase, use the heat energy stored by heat exchange between the second particles and the fluid working medium in the fluidized bed to heat water entering the heat extraction pipeline to generate steam, and then transmit the steam to the steam application unit; The first particles are encapsulated phase change material particles, the second particles are high temperature resistant solid particles, and the size of the first particles is larger than the size of the second particles; The specific heat capacity of the fluid working medium is greater than 2000 J / (kg·°C).

2. The fluidized bed energy storage system according to claim 1, characterized in that: A circulation pump is provided on the circulation pipeline between the fluidized bed heat storage and release unit and the energy supply unit. The circulation pump is used to control the fluid working medium in the circulation pipeline to circulate along a preset circulation path when it is turned on.

3. The fluidized bed energy storage system according to claim 1, characterized in that: The first particles are spherical particles with a particle size ranging from 10 mm to 50 mm, and the second particles are particles with a particle size ranging from 0 μm to 200 μm.

4. The fluidized bed energy storage system according to claim 1, characterized in that: The working range of the first particles is 200°C to 600°C.

5. The fluidized bed energy storage system according to any one of claims 1 to 4, characterized in that: The fluidized bed heat storage and release unit also includes a gas inlet and a gas outlet. The fluidized bed heat storage and release unit is used to introduce gas into the fluidized bed from the gas inlet during the heat release stage. The second particles are heated by the gas and the water in the heat absorption pipe to generate steam. During the heat storage stage, the gas supply to the fluidized bed is stopped.

6. The fluidized bed energy storage system according to claim 5, characterized in that: The gas velocity when the gas is passed through the fluidized bed is 2 to 10 times the minimum fluidization velocity of the second particles.

7. A fluidized bed energy storage system according to any one of claims 1 to 6, characterized in that: The fluidized bed is an adiabatic fluidized bed, and the shell of the fluidized bed is wrapped with a heat-insulating layer.

8. A heat storage and release method based on a fluidized bed heat storage system, characterized in that: Applied to the fluidized bed energy storage system according to any one of claims 1 to 7, the method comprises: The energy supply unit is used to collect energy, and the energy is used to heat the fluid working medium in the circulation pipeline, and the heated fluid working medium is transported to the fixed bed of the fixed bed heat storage unit through the circulation pipeline; After the first particles in the fixed bed are subjected to heat exchange treatment with the fluid working medium, the fluid working medium is transported to the fluidized bed of the fluidized bed heat storage and release unit through the circulation pipeline; When the fluidized bed heat storage and release unit is in the heat storage stage, the fluid working medium and the second particles are heat-exchanged in the fluidized bed, and the fluid working medium after heat exchange is transported to the energy supply unit for heating; When the fluidized bed heat storage and release unit is in the heat release stage, the heat energy stored by the second particles and the fluid working medium in the fluidized bed is used to heat the water entering the heat extraction pipeline to generate steam, and the steam is transported to the steam application unit.

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