Storage tank for heat storage of particle packed bed

Abstract

A storage tank for heat storage of a particle packed bed is divided into an indirect heat exchange storage tank and a direct heat exchange storage tank and comprises a tank body, a flow distribution device, a baffle, a heat preservation device and an emergency discharge device. The tank body is used for storing solid particles and providing a supporting and storing space for the flow distribution device, the baffle, the heat preservation device and the emergency discharging device; the flow distribution device is used for uniformly distributing heat exchange fluid in the tank body, and the baffle is used for fixing a packed bed body in the tank body and preventing solid particles from flowing out of the tank body; the heat preservation device is used for maintaining the temperature of the packed bed body and providing heat tracing for the tank body when needed, and the emergency discharging device is used for discharging solid particles out of the tank body in an emergency. The distribution pipeline is adopted to distribute flow, so that fluid is uniformly mixed on the section of the storage tank, the problem of insufficient heat exchange of particles in heat storage and heat release processes is solved, and the heat storage efficiency of the packed bed system is improved.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage technology, and more specifically to a storage tank for thermal storage in a particle-filled bed. Background Technology

[0002] Particle-filled bed thermal energy storage technology is a technique that stores thermal energy by increasing the temperature of the medium. It boasts advantages such as simple principles and mature technology. Storage media include materials such as sand, crushed rock, and metal particles. Currently, there are commercial cases of solid particle thermal energy storage both domestically and internationally. The Finnish company Polar Night Energy has developed sand battery technology, with energy sources including renewable energy sources such as wind power and photovoltaics. This technology involves embedding pipes in sand storage tanks, through which water, steam, or air can be introduced for heat storage and extraction. In China, Tsinghua University and the Ordos Laboratory have jointly developed a sand thermal battery project. During heat storage, an electric heater heats the sand; during heat extraction, nitrogen gas is introduced, directly contacting the sand for heat exchange. The high-temperature gas can be used to generate steam in subsequent stages for heating, oil extraction, and other purposes.

[0003] The above commercial cases all use packed beds for heat storage. In this design, fluid flows through the packed bed and exchanges heat with the bed composed of particles, thereby completing heat storage and release. However, there are problems in packed beds, such as uneven distribution of fluid inside the bed and the flow velocity in the center is usually significantly higher than that at the edge. This results in insufficient heat exchange at the edge of the bed, causing a delay in the time for the entire packed bed to complete heat storage and release, which affects the efficiency and economy of packed bed heat storage. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the present invention provides a storage tank for heat storage in a particle-filled bed. The storage tank uses a distribution pipeline to distribute the flow rate, so that the fluid is uniformly mixed on the cross-section of the storage tank, which solves the problem of insufficient heat exchange of particles during heat storage and heat release, and improves the heat storage efficiency of the filled bed system.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A storage tank for heat storage in a granular packed bed, the storage tank being divided into an indirect heat exchange storage tank and a direct heat exchange storage tank, the storage tank comprising a tank body, a flow distribution device, a baffle, a heat insulation device, and an emergency discharge device; The tank contains solid particles, and a flow distribution device is also installed inside the tank. The fluid in the flow distribution device passes evenly through the solid particles to exchange heat for the solid particles. The solid particles are placed on the filling bed, and the baffle is used to fix the filling bed inside the tank to prevent the solid particles from flowing out of the tank; The tank body is equipped with a heat preservation device on the outside. The heat preservation device is used to maintain the temperature of the filling bed and provide heat tracing to the tank body when needed. The emergency discharge device is used to discharge solid particles from the tank body in emergency situations.

[0006] When using an indirect heat exchange tank, the fluid in the flow distribution device flows through the solid particles via pipelines without directly contacting the solid particles; When a direct heat exchange tank is used, the fluid in the flow distribution device flows down by gravity and comes into direct contact with the solid particles.

[0007] When using indirect heat exchange storage tanks: The tank is called Tank One, which is placed horizontally and is cylindrical or prismatic in shape. Depending on the heat storage requirements, different sizes and numbers of tanks can be used. Using multiple tanks in parallel can also increase the heat storage capacity.

[0008] The flow distribution device is arranged axially in the tank body. The flow distribution device includes an inlet main pipeline and various distribution pipelines. The overall shape of the pipeline is honeycomb, which makes the fluid evenly distributed across the entire cross-section of the tank body. The inlet main pipeline is connected to the pipeline that connects to the system before the storage tank and is connected to the first-stage distribution pipeline. The first-stage distribution pipeline is connected to the second-stage distribution pipeline in sequence, and the various distribution pipelines are connected in sequence. The various distribution pipelines evenly disperse the heat transfer fluid into the space of the packed bed placed inside the tank body. After heat exchange with the packed bed, the fluid is finally collected through the collection pipeline and gathered into the outlet main pipeline and enters the system after the storage tank.

[0009] The baffle is divided into a front baffle and a rear baffle. The front baffle is installed upstream of the flow direction of the distribution pipeline, and the rear baffle is located downstream of the distribution pipeline to prevent particles in the filling bed from leaking into the upstream and downstream systems. The front baffle, the rear baffle, and the tank form a sealed space for placing the filling bed. The front baffle and the rear baffle have openings for installing the inlet main pipe and the outlet main pipe.

[0010] In the honeycomb flow distribution device, the main inlet pipeline is connected to the pipeline of the system in front of the tank. The pipeline extends axially and has a series of equally spaced outlets on the pipe wall. Three smaller diameter branch pipes branch off from the outlets. The included angle between the branch pipes is 120°. The branch pipes then form a regular hexagonal ring pipeline, which serves as the first-stage distribution pipeline of the outlet. At the vertices of the hexagon of the first-stage distribution pipeline, smaller diameter branch pipes branch off and connect with each other to form a regular hexagonal ring.

[0011] To balance the pressure drop and uniformity of pipeline distribution, the diameter ratio of the first-stage distribution pipeline to the second-stage distribution pipeline is 1.12:1. Each stage of the distribution pipeline is connected sequentially in the manner described above, and the outer apex of the last-stage distribution pipeline at each outlet is connected to each other to form a loop.

[0012] The insulation device is an insulation layer one, which is wrapped around the outside of the tank body. The material is one or a combination of asbestos, glass wool, polyurethane foam, aerogel, etc. The emergency discharge device includes an openable movable window and a cooling pool. The cooling pool is located at the bottom of the tank and the movable window is located on the side of the tank. If the sensor detects that the temperature inside the tank is too high, the movable window is opened to allow solid particles to be discharged from the tank and fall into the cooling pool below, thereby cooling the solid particles. The cooling liquid in the cooling pool should be a non-flammable liquid with high specific heat capacity. The particles constituting the packed bed are materials with high specific heat capacity, high density, and controllable cost, such as sand, metal particles, silicon carbide, or phase change materials. The fluid that exchanges heat with the packed bed can be a medium with high heat transfer coefficient and large specific heat capacity, such as high-pressure water, heat transfer oil, or molten salt.

[0013] When using a direct heat exchange storage tank: The tank is tank two, which is placed vertically. A flow distribution device is installed above tank two. The flow distribution device is a tree-shaped flow distribution device, which includes an inlet main pipeline two, a first-stage distribution pipeline two, and a second-stage distribution pipeline two. The flow distribution pipeline is tree-shaped as a whole. The inlet main pipeline two is connected to the pipeline connected to the system before the storage tank and is connected to the first-stage distribution pipeline two. Then it extends to the second-stage distribution pipeline two. The second-stage distribution pipeline two evenly distributes the heat transfer fluid to the cross-section of tank two. After heat exchange with the packed bed, the fluid naturally collects through the arc-shaped space at the bottom of tank two and enters the system after the storage tank from the outlet main pipeline two.

[0014] In the tree-like flow distribution device, the main inlet pipe 2 is connected to the pipeline connecting to the system before tank 2. To ensure uniform fluid distribution within the overall pipeline, n equal-length branch pipes are radially branched from the main inlet pipe 2, with an included angle of (360 / (n-1))° between adjacent branch pipes. The upper ends of the branch pipes are closed, and a series of equally spaced outlets are opened on the pipe wall. To ensure uniform flow distribution and prevent excessive pressure drop, the outlet spacing should not exceed 8 times the pipe diameter. The outlet of the main inlet pipe 2 is connected to the first-stage distribution pipeline 2.

[0015] Because the larger the diameter of the branch pipe, the more flow is drawn from the main pipe, which also leads to a larger pressure drop in the main pipe, the diameter ratio of the first-stage distribution pipe two to the inlet main pipe two is 1.12:1.

[0016] The first-level distribution pipeline 2 extends radially and then branches into n equal-length branch pipes axially, the same number as the inlet main pipeline 2. The branches of the first-level distribution pipeline 1 are closed at the end, and the pipe wall also has a series of equally spaced outlets, which are connected to the next level, the second-level distribution pipeline 2, in the same way as the inlet main pipeline 2. The various levels of distribution pipelines are connected sequentially.

[0017] The baffle is divided into a second front baffle, a second rear baffle, and a second rear baffle. The second front baffle, the second rear baffle, and the tank body form a closed space, which can be formed into a cylinder, a square prism, or a regular polygonal prism for placing the filling bed. The second front baffle and the second rear baffle have round holes with a diameter smaller than the diameter of the particles that make up the filling bed, so that the heat transfer fluid passes through the baffle and cannot carry out the particles in the filling bed. Under direct contact heat exchange conditions, square, annular, or circular slots are opened on the front baffle 2 and rear baffle 2 of the bed to allow the heat transfer fluid to pass through. The annular slot refers to a series of concentric annular slots with the center of the storage tank as the center. The circular slot is to replace the annular part of the annular slot with a series of circular holes. The square slot is to cut a square grid to fit the size of the tank body 2 as a baffle. The slot size is smaller than the particle diameter to prevent particles from entering the subsequent system through the baffle. The insulation device is a second insulation layer, which is wrapped around the outside of the tank. The material is a combination of one or more materials such as asbestos, glass wool, polyurethane foam, and aerogel. The emergency discharge device includes an openable movable window 2 and a cooling pool 2. The cooling pool 2 is located at the bottom of the tank 2, and the movable window 2 is located on the side of the tank 2. If the sensor detects that the temperature inside the tank is too high, the movable window is opened to allow solid particles to be discharged from the tank and fall into the cooling pool below, thereby cooling the solid particles. The cooling liquid in the cooling pool should be a non-flammable liquid with high specific heat capacity. The particles constituting the packed bed are materials with high specific heat capacity, high density, and controllable cost, such as sand, metal particles, silicon carbide, or phase change materials. The fluids that exchange heat with the packed bed are media with high heat transfer coefficient and large specific heat capacity, such as high-pressure water, heat transfer oil, and molten salt. The last stage of the distribution pipeline is equipped with a nozzle at the end outlet to evenly spray the heat transfer fluid onto the packed bed.

[0018] The beneficial effects of this invention are: This invention employs a fractal uniformly distributed pipeline design, which can optimize the distribution of fluid on the cross-section of the storage tank, improve the uniformity of temperature distribution on the cross-section of the packed bed during heat storage and heat extraction, and improve energy utilization efficiency. At the same time, the distribution pipeline can reduce the pressure drop of the fluid inside the pipeline as a whole, thereby reducing energy loss. A distribution pipeline design is adopted, using a multi-stage self-similar branching structure to progressively decompose the concentrated inflow into numerous parallel smaller streams. This structure utilizes local resistance to dominate pressure drop, mitigating the impact of uneven axial pressure in the main pipe, allowing the fluid to flow out from the end orifice at a low velocity and uniform static pressure, thus achieving uniform fluid distribution across the tank cross-section. In non-optimal distribution systems, fluid kinetic energy is often dissipated through local throttling or abrupt changes in direction, resulting in high local resistance losses. However, in the distribution pipeline, the total fluid flow is distributed across numerous parallel flow paths. By decomposing the concentrated high-flow rate into many parallel, low-flow-rate streams with matched pipe diameters, the high frictional losses caused by high-speed flow in a single channel are avoided, thereby achieving lower overall flow resistance at the system level. This invention uses a liquid with a high heat transfer coefficient as the heat transfer medium, enabling faster heat transfer, reducing uneven heat transfer losses within the bed, and improving the overall efficiency of the packed bed. If the flow rate distribution is uneven, using a high-heat-transfer medium results in faster heat exchange at the center where the flow rate is higher, while the increase in heat exchange at the edges where the flow rate is lower is not significant, potentially exacerbating local temperature unevenness and leading to a decrease in overall efficiency. The technical solution of this invention allows the high heat transfer coefficient of the working medium to be fully utilized globally, enabling synchronous and rapid heat transfer within the bed. Attached Figure Description

[0019] Figure 1 Main view of the design for a storage tank with indirect heat exchange.

[0020] Figure 2 This is a side view of the distribution piping for indirect heat exchange.

[0021] Figure 3 A schematic diagram of the design for a direct contact heat exchange tank.

[0022] The labels in the diagram represent: 1 is the inlet main pipeline, 2 is the first-stage distribution pipeline, 3 is the bed front baffle, 4 is the second-stage distribution pipeline, 5 is the tank body, 6 is the bed rear baffle, 7 is the collection pipeline, 8 is the insulation layer, 9 is the outlet main pipeline, 10 is the movable window, and 11 is the cooling pool. 12 is the second inlet main pipeline, 13 is the second primary distribution pipeline, 14 is the second secondary distribution pipeline, 15 is the second front baffle of the bed, 16 is the second tank body, 17 is the second rear baffle of the bed, 18 is the second outlet main pipeline, 19 is the second insulation layer, 20 is the second movable window, and 21 is the second cooling pool. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings.

[0024] Example 1 like Figure 1, Figure 2 As shown, this embodiment is a tank design for indirect heat exchange, including tank body 5, flow distribution device, baffle, insulation device, and emergency discharge device; The tank 5 is used to store solid particles and provides support and storage space for the flow distribution device, baffles, insulation device, and emergency discharge device. The flow distribution device is used to ensure that the heat exchange fluid is evenly distributed in the tank 5. The baffles are used to fix the solid particle bed and prevent the solid particles from flowing out of the tank 5. The insulation device is used to maintain the temperature of the solid particle bed and provide heat tracing to the tank 5 when needed. The emergency discharge device is used to discharge the solid particles from the tank 5 in an emergency to prevent the temperature inside the tank from becoming too high. In this embodiment, tank 5 is a quadrangular prism. Depending on the heat storage requirements, tanks of different sizes and quantities can be used. The flow distribution device in this embodiment includes an inlet main pipeline 1, a first-stage distribution pipeline 2, a second-stage distribution pipeline 4, and an outlet main pipeline 9. The pipeline is hexagonal in shape. The inlet main pipeline 1 is connected to the pipeline that enters the system before the storage tank and is connected to the first-stage distribution pipeline 2. It then extends to the second-stage distribution pipeline 4. The second-stage distribution pipeline 4 evenly distributes the heat transfer fluid into the space where the packed bed is placed. After heat exchange with the bed, the fluid finally converges into the outlet main pipeline 9 and enters the system after the storage tank. The main inlet pipe 1 enters the tank body 5 from the center of the left side of the storage tank in the figure. The main inlet pipe 1 is connected to the pipeline connected to the system in front of the tank body 5. The pipeline extends axially and has a series of equally spaced outlets on the pipe wall. Three smaller diameter branch pipes branch off from the outlets. The included angle between the branch pipes is 120°. The branch pipes then form a regular hexagonal ring pipeline, which serves as the first-level distribution pipeline 2 of the outlet. At the vertices of the hexagon of the first-level distribution pipeline 2, smaller diameter branch pipes branch off again and connect with each other to form a regular hexagonal ring, which serves as the second-level distribution pipeline 4 of the outlet.

[0025] To balance the pressure drop and uniformity of pipeline distribution, the diameter ratio of the two-stage pipelines is 1.12:1. Each stage of the distribution pipeline is connected sequentially in the manner described above. The outermost vertices of the final-stage distribution pipeline at each outlet are interconnected to form a loop. All distribution pipelines are located inside the bed.

[0026] The baffle is divided into a front baffle 3 and a rear baffle 6. The front baffle 3 is installed upstream of the distribution pipeline in the flow direction, and the rear baffle 6 is located downstream of the distribution pipeline to prevent particles from leaking out of the bed into the upstream and downstream systems. The front baffle 3, the rear baffle 6, and the tank 5 form a closed space for placing the filling bed. Openings are required on the front baffle 3 and the rear baffle 6 to install the inlet main pipeline 1 and the outlet main pipeline 9. The insulation device is insulation layer 8, which is wrapped around the outside of tank body 5. The material is a combination of one or more materials such as asbestos, glass wool, polyurethane foam, and aerogel. If the heat transfer fluid is a medium that is easy to solidify, electric heat tracing can be installed between the insulation layer and the tank body to prevent the temperature from being too low after heat extraction, which would cause the heat transfer fluid to solidify. The emergency discharge device includes an openable movable window 10 and a cooling pool 11, which are located at the bottom of the tank 5. If the sensor detects that the temperature inside the tank is too high, the bottom of the tank 5 is opened to allow solid particles to be discharged from the tank 5 and fall into the cooling pool 11 below, thereby cooling the solid particles. The bottom of the tank is conical to facilitate the discharge of sand. The cooling liquid in the cooling pool 11 should be a non-flammable liquid with a high specific heat capacity to cool the sand quickly. The particles arranged in the packed bed are materials with high specific heat capacity, high density, and controllable cost, such as sand, metal particles, silicon carbide, or phase change materials. The fluid that exchanges heat with the packed bed can be a medium with high heat transfer coefficient and large specific heat capacity, such as high-pressure water, heat transfer oil, or molten salt. During the heat storage process, the hot fluid flows in from the inlet main pipe 1, and transfers heat into the packed bed through the first-stage distribution pipe 2 and the second-stage distribution pipe 4. Then, it flows into the outlet main pipe 9 from the collection pipe 7. During the heat release process, the fluid flows in the opposite direction in the tank 5. The cold fluid enters from the outlet main pipe 9, absorbs heat in the packed bed, and flows out from the inlet main pipe 1. During the thermal storage process, the hot fluid flows in from the inlet main pipeline 1 and is evenly distributed into the bed space through the first-stage distribution pipeline 2 and the second-stage distribution pipeline 2. The hot fluid flows in the pipe and transfers heat to the low-temperature packed bed, which stores the heat. The low-temperature fluid flows into the outlet main pipeline 9 and flows out of the tank 5. During the heat release process, the cold fluid enters the tank 5 from the outlet main pipeline 9 and passes through the first-stage distribution pipeline 2 and the second-stage distribution pipeline 4. The first-stage distribution pipeline 2 includes all the first-stage branch pipes connected in the flow direction from the inlet main pipeline to the outlet main pipeline. Therefore, in sequence, all the fluid flowing in from the main pipeline first enters the first-stage distribution pipeline 2, which evenly distributes the fluid into the packed bed space. The fluid absorbs heat from the high-temperature packed bed and then flows out from the inlet main pipeline 1 and enters the subsequent system for power generation or other thermal energy utilization.

[0027] Example 2 like Figure 3As shown, this embodiment is a tank design for direct contact heat exchange, including a tank body 16, a flow distribution device, a baffle, a heat insulation device, and an emergency discharge device. The tank body 16 stores solid particles and provides support and storage space for the flow distribution device, baffle, heat insulation device, and emergency discharge device. The flow distribution system ensures uniform distribution of the heat exchange fluid within the tank. The baffle fixes the solid particle bed, preventing solid particles from flowing out of the tank body 16. The heat insulation device maintains the temperature of the solid particle bed and provides heat tracing to the tank when needed. The emergency discharge device removes solid particles from the tank in emergencies, preventing excessively high temperatures inside the tank. In this embodiment, the tank is cylindrical. Depending on the heat storage requirements, different sizes and numbers of tanks can be used. The flow distribution device in this embodiment includes an inlet main pipe 2 12, a first-stage distribution pipe 2 13, and a second-stage distribution pipe 2 14. The flow distribution pipes are generally tree-shaped. The inlet main pipe 2 12 is connected to the pipe that enters the system before the storage tank and is connected to the first-stage distribution pipe 2 13. It then extends to the second-stage distribution pipe 2 14. The second-stage distribution pipe 2 14 evenly distributes the heat transfer fluid onto the cross-section of the tank body 2 16. After heat exchange with the bed, the fluid naturally collects through the arc-shaped space at the bottom of the tank body 2 16 and enters the system after the storage tank from the outlet main pipe 2 18. The main inlet pipe 212 is connected to the pipeline of the system before the storage tank. In order to make the fluid evenly distributed in the whole pipeline, n equal-length branch pipes are branched radially from the main inlet pipe 212. The included angle between adjacent branch pipes is (360 / (n-1))°. The upper end of the branch pipe is closed, and a series of equally spaced outlets are opened on the pipe wall. The outlet of the main inlet pipe 2 12 is connected to the first-stage distribution pipe 13. The first-stage distribution pipe 2 13 first extends radially, and then branches into n equal-length branch pipes axially, the same number as the branches of the main inlet pipe 2 12. The ends of the branch pipes of the first-stage distribution pipe 2 13 are closed, and the pipe wall also has a series of equally spaced outlets. It is connected to the next-stage distribution pipe, namely the second-stage distribution pipe 14, in the same way as the main inlet pipe 2 12. Each level of distribution pipe is connected sequentially in the above manner.

[0028] The distribution pipeline is located on the upper side of the bed. The front baffle 15 of the bed is installed downstream of the flow direction of the distribution pipeline and above the bed. The rear baffle 17 of the bed is located below the bed and is used to support the bed and prevent particles in the bed from leaking into the downstream system.

[0029] The baffle is divided into a front baffle 15 and a rear baffle 17. The front baffle 15, the rear baffle 17 and the tank 16 form a closed space for placing the filling bed. The front baffle 15 and the rear baffle 17 have round holes with a diameter smaller than the diameter of the particles that make up the bed, so that the heat transfer fluid passes through the baffle and cannot carry the particles out of the bed. The insulation device is insulation layer 2 19, which is wrapped around the outside of the tank. The material is a combination of one or more materials such as asbestos, glass wool, polyurethane foam, and aerogel. If the heat transfer fluid is a medium that is easy to solidify, electric heat tracing can be installed between the insulation layer and the tank to prevent the temperature from being too low after heat extraction, which would cause the heat transfer fluid to solidify. The emergency discharge device includes an openable movable window 20 and a cooling pool 21, which are located at the bottom of the tank 16. If the sensor detects that the temperature inside the tank is too high, the bottom of the tank is opened to allow solid particles to be discharged from the tank and fall into the cooling pool below, thereby cooling the solid particles. The bottom of the tank is conical to facilitate the discharge of sand. The cooling liquid in the cooling pool should be a non-flammable liquid with high specific heat capacity to cool the sand quickly. The working principle of this embodiment is as follows: During the thermal storage process, the hot fluid flows in from the inlet main pipe 212, and is evenly distributed throughout the bed space via the first-stage distribution pipe 213 and the second-stage distribution pipe 14. The hot fluid flows out from the outlet of the second-stage distribution pipe and into the bed, transferring heat to the low-temperature bed, thus storing heat in the bed. The low-temperature fluid flows into the outlet main pipe 218 and out of the tank 216. During the heat release process, the cold fluid enters the tank 216 from the inlet main pipe 212, and flows through the first-stage distribution pipe 213 and the second-stage distribution pipe 214, exiting at the outlet of the second-stage distribution pipe 214. The fluid is evenly distributed throughout the bed space, absorbing heat from the high-temperature bed. The high-temperature fluid then flows out from the outlet main pipe 218 and enters the subsequent system for power generation or other thermal energy utilization.

[0030] The particles constituting the packed bed can be materials with high specific heat capacity, high density, and controllable cost, such as sand, metal particles, silicon carbide, or phase change materials. The fluid exchanging heat with the packed bed can be a medium with high heat transfer coefficient and large specific heat capacity, such as high-pressure water, thermal oil, or molten salt. Using a cylindrical storage tank with a diameter of 200mm and a length of 1m, with thermal oil as the heat transfer medium and a flow rate of 0.5t / h, and employing only a flow equalization orifice plate, the maximum temperature difference at the central section of the tank can reach 10℃ after 10 minutes of heat storage. The required heat storage time for the packed bed to heat from room temperature to 200℃ is approximately 20 minutes. After adding a two-stage distribution pipeline flow equalization device, the maximum temperature difference at the central section reaches 7℃ after 10 minutes of heat storage, and the required heat storage time is approximately 17 minutes. The heat storage time is reduced by 3.5%, and the temperature non-uniformity is reduced by 3%.

Claims

1. A tank for particle packed bed thermal storage, characterized by, The tank is divided into indirect heat exchange tank and direct heat exchange tank, the tank comprises a tank body, a flow distribution device, a baffle, a heat preservation device and an emergency discharge device; The tank body stores solid particles, and the flow distribution device is arranged in the tank body, and the fluid in the flow distribution device uniformly passes through the solid particles to exchange heat with the solid particles; The solid particles are placed on a packed bed, and the baffle is used to fix the packed bed in the tank body to prevent the solid particles from flowing out of the tank body; The heat preservation device is arranged outside the tank body, and is used to maintain the temperature of the packed bed and provide heat tracing for the tank body when needed, and the emergency discharge device is used to discharge the solid particles out of the tank body in an emergency; When the indirect heat exchange tank is used, the fluid in the flow distribution device passes through the solid particles through a pipeline without directly contacting the solid particles; When the direct heat exchange tank is used, the fluid in the flow distribution device flows down by gravity and directly contacts the solid particles.

2. A tank for heat storage in a packed bed of particles according to claim 1, characterized in that, When the indirect heat exchange tank is used: The tank body is a tank body one (5), and the tank body one (5) is horizontally placed, The flow distribution device is arranged in the tank body one (5) in the axial direction, and the flow distribution device comprises an inlet main pipeline one (1) and various levels of distribution pipelines, the overall shape of the pipeline in the cross section perpendicular to the flow direction is a hexagon, so that the fluid is uniformly distributed on the entire cross section of the tank body one (5), the inlet main pipeline one (1) is connected with the pipeline connected to the system in front of the tank, and is connected to the first level of distribution pipeline one (2), the first level of distribution pipeline one (2) is sequentially connected with the second level of distribution pipeline two (4), and the various levels of distribution pipelines are sequentially connected; the various levels of distribution pipelines uniformly disperse the heat transfer fluid into the space of the packed bed placed in the tank body one (5), and after completing heat exchange with the packed bed, the fluid is finally collected into an outlet main pipeline one (9) through a collection pipeline one (7) and enters the system behind the tank.

3. A tank for heat storage in a packed bed of particles according to claim 2, characterized in that, The baffle is divided into a bed layer front baffle one (3) and a bed layer rear baffle one (6), the bed layer front baffle one (3) is installed on the upstream of the flow direction of the distribution pipeline, and the bed layer rear baffle one (6) is arranged on the downstream of the distribution pipeline, and is used to prevent the particles in the packed bed from leaking into the upstream and downstream systems; The bed layer front baffle one (3), the bed layer rear baffle one (6) and the tank body one (5) form a closed space for placing the packed bed, and holes are formed in the bed layer front baffle one (3) and the bed layer rear baffle one (6) to install the inlet main pipeline one (1) and the outlet main pipeline one (9).

4. A tank for heat storage in a packed bed of particles according to claim 3, characterized in that In the honeycomb flow distribution device, the inlet main pipeline one (1) is connected with the pipeline connected to the system in front of the tank body one (5), the pipeline extends in the axial direction, a series of equidistant outlets are formed on the wall of the pipeline, three branch pipes with small diameters are divided at the outlets, the included angle between the branch pipes is 120°, the branch pipes then form a regular hexagonal ring pipeline as the first level of distribution pipeline one (2), smaller branch pipes are further divided at the vertices of the hexagonal ring of the first level of distribution pipeline one (2) and are connected with each other to form a regular hexagonal ring pipeline. The diameter ratio of the first distribution pipeline (2) to the second distribution pipeline (4) is 1.1-2:1, and each outlet is connected to the outside vertex of the last stage of the distribution pipeline to form a loop.

5. A tank for heat storage in a packed bed of particles according to claim 4, characterized in that, The heat preservation device is a heat preservation layer (8) wrapped outside the tank body, and the material is one or a combination of several materials such as asbestos, glass wool, foamed polyurethane, and aerogel. The emergency discharge device includes an openable movable window (10) and a cooling pool (11), the cooling pool (11) is arranged at the bottom of the tank body (5), and the movable window (10) is arranged on the side of the tank body (5), and the cooling liquid in the cooling pool (11) should be a liquid with high specific heat capacity and non-flammability. The particles constituting the packed bed are sand, metal particles, silicon carbide or phase change materials, and the fluid for heat exchange of the packed bed is high-pressure water, heat-conducting oil or molten salt.

6. A tank for heat storage in a packed bed of particles according to claim 2, characterized in that, When a direct heat exchange storage tank is used: The tank body is a tank body (16), the tank body (16) is vertically placed, a flow distribution device is arranged above the tank body (16), the flow distribution device is a tree-shaped flow distribution device, the flow distribution device includes an inlet main pipeline (12), a first distribution pipeline (13), and a second distribution pipeline (14), the flow distribution pipeline is tree-shaped as a whole, the inlet main pipeline (12) is connected to the pipeline of the system connected to the front of the storage tank and connected to the first distribution pipeline (13), and then expanded to the second distribution pipeline (14), the second distribution pipeline (14) uniformly disperses the heat transfer fluid to the cross section of the tank body (16), and after completing heat exchange with the packed bed, the fluid is naturally collected through the arc-shaped space at the bottom of the tank body (16) and enters the system after the storage tank from the outlet main pipeline (18).

7. A tank for heat storage in a packed bed of particles according to claim 6, characterized in that In the tree-shaped flow distribution device, the inlet main pipeline (12) is connected to the pipeline of the system connected to the front of the tank body (16), n equal-length branch pipes are radially branched from the inlet main pipeline (12), the included angle between adjacent branch pipes is (360 / (n-1))°, the end of the branch pipe is closed, and a series of equally spaced outlets are arranged on the pipe wall; the outlet spacing should not exceed 8 times the pipe diameter, and the outlet of the inlet main pipeline (12) is connected to the first distribution pipeline (13); The diameter ratio of the first distribution pipeline (13) to the inlet main pipeline (12) is 1.12:

1.

8. A tank for heat storage in a packed bed of particles according to claim 7, characterized in that The first distribution pipeline (13) first extends radially, and then axially branches into n equal-length branch pipes, which are the same in number as the branches of the inlet main pipeline (12), the end of the branch pipe of the first distribution pipeline (2) is closed, a series of equally spaced outlets are arranged on the pipe wall, and the first distribution pipeline (2) is connected to the second distribution pipeline (14) of the next stage in the same way as the connection of the inlet main pipeline (12), and the distribution pipelines are sequentially connected.

9. A tank for heat storage in a packed bed of particles according to claim 6, characterized in that, The baffle is divided into a front baffle two (15) and a rear baffle two (17), the front baffle two (15) and the rear baffle two (17) and the tank body two (16) form a closed space, and form a cylinder, a quadrangular prism or a regular polygonal prism, and are used for placing a packed bed body, and the front baffle two (15) and the rear baffle two (17) are provided with circular holes, the diameters of the circular holes are smaller than the diameters of particles constituting the packed bed body, so that the heat transfer fluid passes through the baffle and cannot take out the particles in the packed bed body.

10. The tank for heat storage of a granular packed bed according to claim 6, characterized in that, The heat preservation device is a heat preservation layer two (19), the heat preservation layer two (19) is wrapped outside the tank body, and the material is one or a combination of several materials such as asbestos, glass wool, foamed polyurethane and aerogel; The emergency discharge device comprises an openable movable window two (20) and a cooling pool two (21), the cooling pool two (21) is arranged at the bottom of the tank body two (16), and the movable window two (20) is arranged at the side of the tank body two (16); the cooling liquid in the cooling pool two (21) should be a liquid with high specific heat capacity and non-flammability; The particles constituting the packed bed body are sand, metal particles, silicon carbide or phase change materials, and the fluid for heat exchange of the packed bed body is high-pressure water, heat-conducting oil or molten salt; A nozzle is arranged at the end of the last stage of the distribution pipeline, and the heat transfer fluid is uniformly sprayed on the packed bed body.

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