Bubbling fluidized bed thermochemical heat storage reactor

Abstract

The utility model provides a bubbling fluidized bed thermochemical heat storage reactor, and relates to the technical field of energy storage. The device comprises a shielding layer, an electromagnetic induction coil layer and a heat storage reactor inner wall from outside to inside, and a cavity defined by the heat storage reactor inner wall is filled with thermochemical heat storage materials and induction heating particles which can be jointly fluidized. An air distribution device is arranged at the bottom of the cavity and communicated with the air chamber, and a gas outlet is formed in the top of the cavity. The induction heating particles heated by electromagnetic induction are used as a heat source, and the heat storage material is heated in the reactor cavity. The power regulation of electromagnetic induction heating is more sensitive, so that the temperature rise effect is fed back more quickly. And when the inner wall of the heat storage reactor is also made of a metal material, the heat storage reactor can become a heat source under the action of the electromagnetic induction coil layer, and high-temperature fluidizing air with a heating function is added, so that multiple heat sources are used for heating at the same time, and rapid input of high-power heat energy and efficient heat energy storage can be realized.

Description

Technical Field

[0001] This utility model relates to the field of energy storage technology, and in particular to a bubbling fluidized bed thermochemical thermal storage reactor. Background Technology

[0002] Against the backdrop of large-scale use of fossil fuels, the widespread utilization of renewable energy is crucial for reducing greenhouse gas emissions and mitigating climate change. However, with the significant increase in renewable energy generation, the stability of the power system has faced considerable challenges. One of the recognized solutions to address the imbalance and instability of renewable energy supply and demand is the use of energy storage technology to regulate the power generation system. Currently, technologies that convert electrical energy into thermal energy for storage can be classified into three categories according to their thermal storage mechanisms: sensible thermal storage, latent thermal storage, and thermochemical thermal storage. Among them, thermochemical thermal storage utilizes reversible chemical reactions, absorbing energy through endothermic reactions and releasing energy through exothermic reactions. Compared to the former two, thermochemical thermal storage has a higher energy density, meaning it can store more energy in the same volume, and suffers from lower heat loss during long-term energy storage processes, effectively improving the flexibility of the power generation system.

[0003] Commonly used thermochemical thermal storage materials are mainly classified into metal oxides, hydrides, hydroxides, carbonates, and ammonia. Among these, the calcium hydroxide / calcium oxide material system has a promising future due to its low cost, non-toxicity, high energy density, and fast reaction rate. During thermal storage, calcium hydroxide absorbs heat and decomposes to produce calcium oxide and water vapor, storing thermal energy as chemical energy. During exothermic reactions, calcium oxide and water vapor react to form calcium hydroxide, releasing the stored chemical energy as heat. The thermal storage temperature range of this material system is typically 400-600℃, and the exothermic temperature range is typically 25-510℃ (at normal pressure). The thermal storage and exothermic power can be flexibly adjusted by controlling the heat input and water vapor partial pressure. The dehydration of calcium hydroxide and the hydration of calcium oxide are typical gas-solid reversible reactions, and their reaction process is greatly affected by heat and mass transfer. High temperature and low water vapor levels favor the thermal storage reaction, while the hydration reaction is the opposite. Therefore, heat and mass transfer within the reactor is crucial. For gas-solid reactions, fixed-bed reactors and fluidized-bed reactors are commonly used. Among them, fluidized-bed reactors can enhance heat and mass transfer, thereby providing higher energy storage / release power. At the same time, fluidized-bed reactors can also achieve continuous feeding and discharging, so they can also decouple energy storage power and capacity.

[0004] Chinese patent application number "2023227433928" discloses an intermittent heat storage and release system based on a fluidized bed, which uses only high-temperature fluidizing air to provide the heat required for the heat storage reaction process. However, the flow rate and velocity of the high-temperature fluidizing air have upper limits, thus limiting the amount of heat that can be input into the heat storage reactor. Furthermore, the intrinsic chemical reaction rate of calcium hydroxide dehydration in carbide slag is relatively fast. Therefore, the technical solution of providing heat solely through high-temperature fluidizing air is insufficient to meet the heat requirements of the calcium hydroxide dehydration reaction, limiting the material reaction rate within the heat storage reactor and consequently limiting the heat storage capacity of the reactor. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a bubbling fluidized bed thermochemical thermal storage reactor. An electromagnetic induction coil is installed on the outside of the thermal storage reactor, and hollow metal particles are filled inside the reactor. Under the action of the electromagnetic induction coil, the hollow metal particles become a heat source to heat the thermal storage material, thereby achieving rapid input of high-power thermal energy and efficient thermal energy storage.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] This utility model provides a bubbling fluidized bed thermochemical thermal storage reactor, which includes, from the outside to the inside: a shielding layer, an electromagnetic induction coil layer, and an inner wall of the thermal storage reactor. The cavity enclosed by the inner wall of the thermal storage reactor is filled with thermochemical thermal storage material and induction heating particles that can be fluidized together. An air distribution device is provided at the bottom of the cavity, and the air distribution device is connected to a ventilation chamber. A gas outlet is provided at the top of the cavity.

[0008] Optionally, the inner wall of the thermal storage reactor is made of metal.

[0009] Optionally, a heat insulation layer is provided between the shielding layer and the electromagnetic induction coil layer, and the heat insulation layer is made of one or more of aerogel felt, slag wool and rock wool.

[0010] Optionally, the thermochemical thermal storage material includes carbide slag.

[0011] Optionally, the induction heating particles are ferromagnetic hollow particles, and the material includes one or more of ferrite, silicon steel and permalloy.

[0012] Optionally, the induction heating particles belong to one or more of Gerldart Class A and Class B particles.

[0013] Optionally, the air distribution device may be a float-type air cap, a rotor-type air cap, a stator-type air cap, or a bell-type air cap.

[0014] Optionally, the gas outlet is equipped with a gas-solid separation device.

[0015] Optionally, the gas-solid separation device is a cyclone separator.

[0016] Optionally, a temperature sensor is provided in the cavity, and the temperature sensor and the electromagnetic induction coil layer are respectively connected to the controller.

[0017] The beneficial effects of this utility model are as follows:

[0018] 1. This invention features an electromagnetic induction coil layer on the outside of the thermal storage reactor cavity, with induction heating particles inside. These particles, heated by electromagnetic induction, serve as the heat source for heating the thermal storage material within the reactor cavity. Because electromagnetic induction heating offers more sensitive power adjustment and faster temperature feedback, it achieves a uniform heat source across the entire reactor structure. When the inner wall of the thermal storage reactor is also made of metal, it can also become a heat source under the influence of the electromagnetic induction coil layer. Combined with high-temperature fluidizing air, which also provides heating, the simultaneous heating from multiple heat sources meets the heat requirements corresponding to the endothermic dehydration reaction rate of calcium hydroxide, enabling rapid input of high-power thermal energy and efficient thermal energy storage. The entire device boasts advantages such as simple structure, ease of installation, high energy efficiency, and uniform temperature distribution.

[0019] 2. In this invention, the calcium carbide slag used as a thermochemical heat storage material will experience particle size reduction due to breakage after multiple heat storage and release cycles, thus decreasing the fluidization quality within the fluidized bed heat storage reactor. However, the induction heating particles do not undergo particle size change and can disturb the finer-particle-size calcium carbide slag material, thereby stabilizing the fluidization and effectively extending the number of heat storage and release cycles for each batch of calcium carbide slag. Furthermore, the blending of large-diameter, high-temperature resistant hollow metal particles can effectively reduce the minimum fluidization velocity of the calcium carbide slag material, thereby effectively reducing the energy consumption of the blower.

[0020] 3. The induction heating particles of this utility model are high-temperature resistant hollow metal particles. They are made of materials with high magnetic permeability and have high energy utilization efficiency. When the performance of the carbide slag material deteriorates and the material needs to be replaced, it can be separated from the carbide slag material by magnetic attraction to achieve recycling and has high economic efficiency. Attached Figure Description

[0021] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0022] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0023] Figure 1 This is a schematic diagram of the structure of the bubbling fluidized bed thermochemical thermal storage reactor in a specific embodiment.

[0024] Figure 2 This is a top view schematic diagram of the bubbling fluidized bed thermochemical thermal storage reactor in a specific embodiment.

[0025] The components include: 1. Inner wall of the thermal storage reactor; 2. Electromagnetic induction coil layer; 3. Thermal insulation layer; 4. Shielding layer; 5. Air chamber; 6. Air distribution device; 7. Thermochemical thermal storage material; 8. Induction heating particles; 9. Gas-solid separation device; 10. Controller; 11. Temperature sensor. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] To overcome the current limitations in thermal storage power of thermal storage reactors and address the issue of low heat input power within these reactors, an innovative design was developed for the thermal storage process, proposing a novel bubbling fluidized bed thermochemical thermal storage reactor, such as... Figure 2 As shown, from the outside in, it includes: a shielding layer 4, an electromagnetic induction coil layer 2, and the inner wall 1 of the thermal storage reactor, as follows: Figure 1 As shown, the cavity enclosed by the inner wall 1 of the thermal storage reactor is filled with thermochemical thermal storage material 7 and induction heating particles 8, which can be fluidized together; such as Figure 2 As shown, the shielding layer 4, the electromagnetic induction coil layer 2, and the inner wall 1 of the thermal storage reactor have circular cross-sections. Therefore, the cavity enclosed by the inner wall 1 of the thermal storage reactor is as follows: Figure 1 The cylinder is shown. The bottom surface of the cylindrical cavity is equipped with an air distribution device 6, which is connected to a ventilation chamber 5. The top surface of the cylindrical cavity is sealed by the inner wall 1 of the thermal storage reactor and is equipped with a gas outlet.

[0028] The electromagnetic induction coil layer 2 includes an electromagnetic induction coil, which can heat the induction heating particles 8. The induction heating particles 8 are evenly distributed in the thermochemical heat storage material 7, which can uniformly heat the thermochemical heat storage material 7. Since the heating power of electromagnetic induction is more sensitive to adjustment and the heating effect is more rapid, it can overcome the technical problem in the background technology that the technical solution of providing heat by only high temperature fluidizing air is difficult to meet the heat demand of the calcium hydroxide endothermic dehydration reaction when carbide slag is used as thermochemical heat storage material 7.

[0029] The inner wall 1 of the thermal storage reactor is made of metal, which can also generate a thermal effect under the action of the electromagnetic induction coil layer 2, and serve as a heat source to heat the thermochemical thermal storage material 7 in the cavity, thereby further improving the heating efficiency.

[0030] A heat insulation layer 3 is provided between the shielding layer 4 and the electromagnetic induction coil layer 2. The heat insulation layer 3 is made of aerogel felt, which has the function of heat preservation and prevents heat leakage in the heat storage reactor.

[0031] The shielding layer 4 includes silicon steel sheets to prevent the magnetic field generated by the electromagnetic induction coil from affecting the normal operation of other circuits and components outside this device.

[0032] Thermochemical thermal storage material 7 is calcium carbide slag, a byproduct of the production of polyvinyl chloride (PVC) using the coal-based calcium carbide method. It is a bulk industrial solid waste, with calcium hydroxide as its main component, accounting for approximately 80% by mass. It features a wide particle size distribution, encompassing Gerdart C, A, and B particles. Compared to high-quality calcium hydroxide Gerdart C particles (~4μm), calcium carbide slag can directly achieve bubbling fluidization, while high-quality calcium hydroxide requires other auxiliary technologies (such as granulation technology) to achieve bubbling fluidization. Therefore, from both a technical and economic perspective, calcium carbide slag is a calcium hydroxide-based thermochemical thermal storage material with potential for industrial application.

[0033] The induction heating particles 8 are ferromagnetic hollow particles made of manganese-zinc ferrite, which have high magnetic permeability, thereby achieving a high heating rate. The mass ratio of the induction heating particles 8 to the thermochemical heat storage material 7 is 1:19.

[0034] Induction heating particles 8 belong to the Gerdart B class of particles; their particle density is 2260 kg / m³. 3 The particle density of carbide slag is 2259.4 kg / m³. 3 Similar to the outer diameter of 170 μm, it belongs to the Gerdart B class of particles and has a wall thickness of 68 μm; making its minimum fluidization velocity less than 10 cm / s; this design enables the induction heating particles 8 to achieve co-fluidization with the thermochemical thermal storage material 7 in the thermal storage reactor, and the induction heating particles 8 are uniformly dispersed in the thermochemical thermal storage material 7.

[0035] The air distribution device 6 uses a rotor-type air cap, which can achieve uniform air distribution and keep the mixed material composed of induction heating particles 8 and thermochemical heat storage material 7 in a bubbling fluidized state.

[0036] A gas-solid separation device 9 is installed at the gas outlet. The gas-solid separation device 9 is a cyclone separator to prevent the mixed materials from being discharged from the thermal storage reactor with the fluidizing air.

[0037] A temperature sensor 11 is installed in the cavity. The temperature sensor 11 and the electromagnetic induction coil layer 2 are respectively connected to the controller 10. The output power of the electromagnetic induction coil in the electromagnetic induction coil layer 2 is adjusted according to the detection result of the temperature sensor 11 to ensure that the internal temperature of the thermal storage reactor does not exceed 600℃, so as to avoid sintering of the mixed materials.

[0038] When the renewable energy generation exceeds the electricity demand, the aforementioned bubbling fluidized bed thermochemical thermal storage reactor starts operating, converting the excess electrical energy into thermal energy and storing it in the material structure of carbide slag inside the thermal storage reactor. The specific thermal storage process is as follows.

[0039] Before the heat storage process begins, the mixed material consisting of thermochemical heat storage material 7 (carbide slag) and induction heating particles 8 is located inside the cavity enclosed by the inner wall 1 of the heat storage reactor.

[0040] A gas source connected to the outside of the air chamber 5 supplies high-temperature nitrogen gas at 500°C into the air chamber 5. Then, under the action of the air distribution device 6, the air is evenly distributed into the cavity, thereby making the mixed material in the thermal storage reactor in a bubbling fluidized state. The fluidization air velocity used at this time is 12cm / s. The excess electrical energy generated by renewable energy in the grid is transmitted to the electromagnetic induction coil layer 2 through the controller 10 to generate a high-intensity alternating magnetic field. The inner wall 1 of the thermal storage reactor and the induction heating particles 8 will generate an eddy current effect under the action of the high-intensity alternating magnetic field, thereby causing the inner wall 1 of the thermal storage reactor and the induction heating particles 8 to heat up rapidly due to the heating effect of their own resistance, thereby converting electrical energy into heat energy, which becomes the heat source for heating the thermochemical thermal storage material 7. At the same time, the temperature feedback of the temperature sensor 11 is used to adjust the controller 10 to ensure that the temperature of the thermochemical thermal storage material 7 does not exceed 600°C, so as to avoid material sintering.

[0041] The thermal storage reactor maintains a stable bubbling fluidization. The thermochemical thermal storage material 7 undergoes an endothermic dehydration reaction by convective heat exchange with three heat sources (high-temperature fluidizing air, high-temperature inner wall of the thermal storage reactor 1, and high-temperature induction heating particles 8), producing dehydration products of carbide slag with calcium oxide as the main component and water vapor, thereby storing heat in the material structure.

[0042] Water vapor and some fine particles will enter the gas-solid separation device 9 with the fluidizing air. After being separated by the gas-solid separation device 9, the water vapor and the uncaptured fine particles will enter the subsequent processing flow.

[0043] The heat storage process ends when all the thermochemical heat storage material 7 in the heat storage reactor is dehydrated.

[0044] After multiple heat storage and release cycles, when the performance of the thermochemical heat storage material 7 deteriorates and fresh material needs to be replaced, the induction heating particles 8 are separated from the thermochemical heat storage material 7 by magnetic attraction, thereby realizing the recycling of the induction heating particles 8.

[0045] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A bubbling fluidized bed thermo-chemical heat storage reactor, characterized in that, From outside to inside, it comprises a shielding layer, an electromagnetic induction coil layer and an inner wall of a thermal storage reactor, a cavity surrounded by the inner wall of the thermal storage reactor is filled with thermal chemical storage materials and induction heating particles which can be fluidized together; a wind distribution device is arranged at the bottom of the cavity, the wind distribution device is communicated with an air chamber, and a gas outlet is arranged at the top of the cavity.

2. The bubbling fluidized bed thermo-chemical heat storage reactor according to claim 1, characterized in that, The inner wall of the thermal storage reactor is made of metal.

3. The bubbling fluidized bed thermo-chemical heat storage reactor of claim 1, wherein, An insulating layer is arranged between the shielding layer and the electromagnetic induction coil layer, and the material of the insulating layer comprises one or more of aerogel felt, slag wool and glass fiber.

4. The bubbling fluidized bed thermo-chemical heat storage reactor of claim 1, wherein, The thermal chemical storage material comprises calcium carbide slag.

5. The bubbling fluidized bed thermo-chemical heat storage reactor of claim 1, wherein, The induction heating particles are ferromagnetic hollow particles, and the material comprises one or more of ferrite, silicon steel and permalloy.

6. The bubbling fluidized bed thermo-chemical heat storage reactor according to claim 5, characterized in that The induction heating particles belong to one or more of Geldart A particles and B particles.

7. The bubbling fluidized bed thermo-chemical heat storage reactor of claim 1, wherein, The wind distribution device comprises one of a float type air cap, a rotor type air cap, a stator type air cap and a bell type air cap.

8. The bubbling fluidized bed thermochemical heat storage reactor of claim 1, wherein, The gas outlet is provided with a gas-solid separation device.

9. The bubbling fluidized bed thermo-chemical heat storage reactor according to claim 8, characterized in that, The gas-solid separation device is a cyclone separator.

10. The bubbling fluidized bed thermochemical heat storage reactor of claim 1, wherein, A temperature sensor is arranged in the cavity, and the temperature sensor and the electromagnetic induction coil layer are respectively connected with a controller.

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