A system for storing heat using solid particles

Abstract

The application discloses a system for storing heat by using solid particles and relates to the technical field of heat storage equipment, which uses solid particles as heat storage materials, heats the solid particles by using electric energy, and generates steam through a solid particle steam generating system. The system comprises a low-temperature particle storage tank, an electric heating particle device, a high-temperature particle storage tank, a particle steam generating system, a storage tank horizontal conveying platform, a storage tank vertical conveying platform and other equipment. The solid particles flow from top to bottom in the electric heating particle device and the particle steam generating system by gravity. The low-temperature particle storage tank and the high-temperature particle storage tank are integrally moved through the storage tank horizontal conveying platform and the storage tank vertical conveying platform. The application is suitable for converting electric energy into heat energy for heat power generation, steam production and hot water production and has a wide application prospect in industrial and agricultural fields.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage equipment technology, and in particular to a system for thermal energy storage using solid particles. Background Technology

[0002] Utilizing off-peak electricity to heat thermal storage materials to hundreds of degrees Celsius and store them as thermal energy, then releasing the heat as needed during peak hours via heat exchange devices, provides hot water and steam, achieving a balanced heating effect throughout the day. This is an effective method to improve the utilization rate of new energy sources. Compared with traditional pumped hydro storage and electrochemical energy storage technologies, the advantages of using thermal storage systems for off-peak electricity utilization are low cost, ease of promotion, long service life, and ease of maintenance. Thermal storage technologies can be divided into three categories according to the storage medium: sensible heat storage, latent heat storage, and thermochemical heat storage. Thermochemical heat storage utilizes the thermal effects of forward and reverse chemical reactions to store and release heat, but its technology maturity is relatively low. Latent heat storage utilizes the phase change latent heat of materials, but there are no mature commercial application demonstrations yet. Sensible heat storage utilizes the specific heat capacity of the material itself, storing and releasing heat through temperature changes, and this technology is the most mature. Currently, sensible heat storage materials such as water and molten salt have narrow operating temperature ranges, requiring a large amount of material for the same storage capacity. Expanded clay sand and quartz sand are used. When solid particles such as river sand are used as thermal storage materials, their operating temperature range is wide, typically from -40℃ to 1300℃. These materials are chemically stable and readily available. Due to the wide operating temperature range of solid particles, their thermal storage density can be increased by raising the thermal storage temperature difference when used for sensible heat storage. Chinese patent CN209415569U discloses a molten salt thermal energy storage power generation and heating system for power plants, converting off-peak electricity into molten salt thermal energy for storage and heating, or using a molten salt exothermic thermal cycle power generation system during peak hours. The operating temperature range of molten salt is between its freezing and decomposition temperatures, typically below 300℃, resulting in insufficient thermal storage density. Chinese patent CN112393210 discloses a phase change thermal energy storage steam supply technology. The thermal storage device is equipped with coil components and encapsulated with high-temperature phase change thermal energy storage materials and electric heating tubes. This device has high integration and high thermal storage density; however, high-temperature phase change materials are typically highly corrosive and costly. Chinese patent CN111075668A discloses an energy storage system utilizing solid particles for thermal storage, but it employs a hoist to transport the high-temperature solid particles, resulting in significant technical risks and high self-energy consumption. Chinese patent CN113323828A discloses a high-efficiency particle thermal storage and utilization system and method, which uses a blower to propel the solid particles through a heat exchanger, also resulting in high self-energy consumption. Chinese patent CN114777545A discloses an integrated solid particle thermal storage device, where the heat exchange tubes are directly embedded within the solid particles, but the solid particles do not flow, leading to poor heat transfer. Summary of the Invention

[0003] The purpose of this invention is to provide a system for storing heat using solid particles to solve the problems existing in the prior art. The system stores electricity through the storage of heat using solid particles. When there is a surplus of electrical energy, the electrical energy is converted into the thermal energy of the solid particles through electric heating and stored. The stored high-temperature solid particles heat water to produce steam.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a system for heat storage using solid particles, including an electrically heated solid particle system, a solid particle heating water supply steam generation system, and a particle storage tank transportation system;

[0006] The electrically heated solid particle system includes a low-temperature particle storage tank, an electrically heated particle device, and a high-temperature particle storage tank arranged sequentially from top to bottom. The outlet of the low-temperature particle storage tank is connected to the inlet of the electrically heated particle device, and the outlet of the electrically heated particle device is connected to the inlet of the high-temperature particle storage tank.

[0007] The solid particle heating water supply steam generation system includes a high-temperature particle storage tank, a particle steam generation system, and a low-temperature particle storage tank arranged sequentially from top to bottom. The outlet of the high-temperature particle storage tank is connected to the particle inlet of the particle steam generation system, and the particle outlet of the particle steam generation system is connected to the inlet of the low-temperature particle storage tank.

[0008] The particle storage tank transportation system includes a horizontal tank transportation platform and a vertical tank transportation platform. The low-temperature particle storage tank and the high-temperature particle storage tank can move horizontally and vertically through the horizontal tank transportation platform and the vertical tank transportation platform.

[0009] Preferably, the cryogenic particle storage tank is a tank for storing solid particles at low temperatures, has a heat preservation function, has a top opening as a feed inlet for solid particles, a bottom opening as a discharge outlet for solid particles, and a cryogenic particle storage tank outlet valve at the discharge outlet.

[0010] Preferably, the electric heating particle device is a device that uses electrical energy to heat particles and has a heat preservation function. Its top opening is the feed inlet for solid particles, and its bottom opening is the discharge outlet for solid particles. The discharge outlet is equipped with an outlet valve for the electric heating particle device.

[0011] Preferably, the high-temperature particle storage tank is a tank for storing solid particles at a high temperature, and has a heat preservation function. Its top opening is the feed inlet for solid particles, and its bottom opening is the discharge outlet for solid particles. The discharge outlet is equipped with a particle outlet valve for the high-temperature particle storage tank.

[0012] Preferably, the particle steam generation system is a device that can release the energy stored in the particles to the feed water to obtain steam, and the discharge port of the particle steam generation system is equipped with a particle outlet valve.

[0013] Preferably, the particulate steam generating system is provided with a steam outlet and a water inlet on one side, and the water inlet is connected to the water supply via a water pump.

[0014] Preferably, the system further includes three platforms arranged sequentially from bottom to top: a first platform, a second platform, and a third platform. The low-temperature particle storage tank, the electric heating particle device, and the high-temperature particle storage tank of the electrically heated solid particle system are respectively located on one side of the third platform, the second platform, and the first platform. The high-temperature particle storage tank, the particle steam generation system, and the low-temperature particle storage tank of the solid particle heating water supply steam generation system are respectively located on the other side of the third platform, the second platform, and the first platform. A horizontal transport platform is provided between the low-temperature particle storage tank and the high-temperature particle storage tank on the first platform, and a horizontal transport platform is also provided between the high-temperature particle storage tank and the low-temperature particle storage tank on the third platform. A vertical transport platform is located between the two horizontal transport platforms.

[0015] Preferably, the system further includes platforms one, two, three, four, and five arranged sequentially from bottom to top. The low-temperature particle storage tank, the electric heating particle device, and the high-temperature particle storage tank of the electrically heated solid particle system are respectively arranged on platforms five, four, and three. The high-temperature particle storage tank, the particle steam generation system, and the low-temperature particle storage tank of the solid particle heating water supply steam generation system are respectively arranged on platforms three, two, and one. A horizontal transport platform is provided between the two high-temperature particle storage tanks on platform three. The low-temperature particle storage tank on platform five is connected to the low-temperature particle storage tank on platform one through the horizontal transport platform and the vertical transport platform.

[0016] The present invention achieves the following beneficial technical effects compared to the prior art:

[0017] (1) It can use solid particles to store heat, and has advantages such as wide operating temperature range, low cost and low operation and maintenance cost.

[0018] (2) The granular storage tank is moved as a whole, and the outer surface temperature of the tank is low, thus avoiding high-temperature transportation.

[0019] (3) Solid particles flow by gravity in the electrically heated particle device and particle steam generation system, resulting in low energy consumption.

[0020] (4) The system capacity can be flexibly designed according to the needs, and can provide hot water, saturated steam and superheated steam, etc., with a wide range of application scenarios. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the system for heat storage using solid particles in Example 1;

[0023] Figure 2 This is a schematic diagram of the system for heat storage using solid particles in Example 2;

[0024] In the diagram: 1. Platform 1; 2. Platform 2; 3. Platform 3; 4. Low-temperature particle storage tank; 5. Electrically heated particle device; 6. High-temperature particle storage tank; 7. Particle steam generation system; 8. Horizontal transport platform for storage tanks; 9. Vertical transport platform for vertical storage tanks; 10. Outlet valve of low-temperature particle storage tank; 11. Outlet valve of electrically heated particle device; 12. Outlet valve of high-temperature particle storage tank; 13. Particle outlet valve of particle steam generation system; 14. Feed water pump; 15. Feed water; 16. Steam; 17. Platform 4; 18. Platform 5. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The purpose of this invention is to provide a system for heat storage using solid particles to solve the problems existing in the prior art.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] The system in this embodiment that utilizes solid particles for heat storage, such as Figure 1 As shown, it includes an electrically heated solid particle system, a solid particle heating water supply steam generation system, and a particle storage tank transportation system;

[0030] The electrically heated solid pellet system includes a low-temperature pellet storage tank 4, an electrically heated pellet device 5, and a high-temperature pellet storage tank 6 arranged sequentially from top to bottom. The outlet of the low-temperature pellet storage tank 4 is connected to the inlet of the electrically heated pellet device 5, and the outlet of the electrically heated pellet device 5 is connected to the inlet of the high-temperature pellet storage tank 6. The solid pellet heating water supply steam generation system includes a high-temperature pellet storage tank 6, a pellet steam generation system 7, and a low-temperature pellet storage tank 4 arranged sequentially from top to bottom. The outlet of the high-temperature pellet storage tank 6 is connected to the pellet inlet of the pellet steam generation system 7, and the pellet outlet of the pellet steam generation system 7 is connected to the inlet of the low-temperature pellet storage tank 4.

[0031] The low-temperature particle storage tank 4 is a tank for storing solid particles at low temperatures. It has a heat preservation function, with a top opening for the solid particles and a bottom opening for the solid particles. The outlet of the solid particles is equipped with a low-temperature particle storage tank outlet valve 10. The electric heating particle device 5 is a device that uses electrical energy to heat the particles. It has a heat preservation function, with a top opening for the solid particles and a bottom opening for the solid particles. The outlet of the solid particles is equipped with an electric heating particle device outlet valve 11. The high-temperature particle storage tank 6 is a tank for storing solid particles at high temperatures. It has a heat preservation function, with a top opening for the solid particles and a bottom opening for the solid particles. The outlet of the solid particles is equipped with a high-temperature particle storage tank particle outlet valve 12. The particle steam generation system 7 is a device that can release the stored energy of the particles to water to obtain steam. The outlet of the particle steam generation system 7 is equipped with a particle steam generation system particle outlet valve 13. A steam outlet and a water inlet are respectively provided on one side of the particle steam generation system 7. The water inlet is connected to the water supply 15 through the water supply pump 14.

[0032] The pellet storage tank transportation system includes a horizontal transport platform 8 and a vertical transport platform 9. The low-temperature pellet storage tank 4 and the high-temperature pellet storage tank 6 move horizontally and vertically through the horizontal transport platform 8 and the vertical transport platform 9.

[0033] In this embodiment, platforms 1, 2, and 3 are arranged sequentially from bottom to top. The low-temperature particle storage tank 4, the electric heating particle device 5, and the high-temperature particle storage tank 6 of the electric heating solid particle system are respectively arranged on one side of platforms 3, 2, and 1. The high-temperature particle storage tank 6, the particle steam generation system 7, and the low-temperature particle storage tank 4 of the solid particle heating water supply steam generation system are respectively arranged on the other side of platforms 3, 2, and 1. A horizontal transport platform 8 is provided between the low-temperature particle storage tank 4 and the high-temperature particle storage tank 6 on platform 1. A horizontal transport platform 8 is also provided between the high-temperature particle storage tank 6 and the low-temperature particle storage tank 4 on platform 3. A vertical transport platform 9 is provided between the two horizontal transport platforms 8.

[0034] The working process of this embodiment is as follows:

[0035] 1) The heating process involves using an electric heating particle device 5 to heat low-temperature solid particles into high-temperature solid particles. At this time, the low-temperature particle storage tank 4 is filled with low-temperature solid particles, while the high-temperature particle storage tank 6 is empty. During operation, the outlet valve of the high-temperature particle storage tank 6 is closed, and the outlet valves of the low-temperature particle storage tank 4 and the electric heating particle device 5 are opened. The electric heating particle device 5 is then activated, and the low-temperature solid particles flow from the low-temperature particle storage tank 4 into the electric heating particle device 5 by gravity, where they are heated into high-temperature solid particles and then flow into the high-temperature particle storage tank 6 for storage.

[0036] 2) The exothermic process involves using high-temperature particles to heat feedwater and obtain steam. During this process, the high-temperature particle storage tank 6 is filled with high-temperature solid particles, while the low-temperature particle storage tank 4 is empty. During operation, the outlet valve of the low-temperature particle storage tank 4 is closed, while the outlet valve of the high-temperature particle storage tank 6 and the particle outlet valve of the particle steam generation system 7 are opened. The feedwater pump 14 is then turned on, and feedwater 15 flows into the particle steam generation system 7. High-temperature solid particles flow from the high-temperature particle storage tank 6 into the particle steam generation system 7 by gravity, heating the feedwater 15 into steam 16, which then flows out. The high-temperature solid particles are cooled into low-temperature solid particles, which then flow into the low-temperature particle storage tank 4 for storage by gravity.

[0037] 3) Particle Storage Tank Movement Process. The cryogenic particle storage tank 4 and the high-temperature particle storage tank 6 are moved horizontally and vertically via the horizontal transport tank platform 8 and the vertical transport tank platform 9, ensuring that the cryogenic particle storage tank 4 and the high-temperature particle storage tank 6 are in suitable positions during the heat charging and heat dissipation processes. To ensure continuous operation during the heat charging and heat dissipation processes, multiple cryogenic particle storage tanks 4 and multiple high-temperature particle storage tanks 6 can be arranged, and the particle storage tanks can be rationally allocated via the horizontal transport tank platform 8 and the vertical transport tank platform 9.

[0038] Example 2:

[0039] like Figure 2As shown, the solid particle heat storage system in this embodiment differs from that in Embodiment 1 only in that: the platform has 5 layers, with the addition of Platform 4 17 and Platform 5 18. Platform 1, Platform 2, Platform 3, Platform 4 17, and Platform 5 18 are arranged sequentially from bottom to top. The low-temperature particle storage tank 4, the electric heating particle device 5, and the high-temperature particle storage tank 6 of the electric heating solid particle system are respectively arranged on Platform 5 18, Platform 4 17, and Platform 3 3. The high-temperature particle storage tank 6, the particle steam generation system 7, and the low-temperature particle storage tank 4 of the solid particle heating water supply steam generation system are respectively arranged on Platform 3 3, Platform 2 2, and Platform 1 1. A horizontal transport platform 8 is provided between the two high-temperature particle storage tanks 6 on Platform 3 3. The low-temperature particle storage tank 4 on Platform 5 18 and the low-temperature particle storage tank 4 on Platform 1 1 are connected by the horizontal transport platform 8 and the vertical transport platform 9.

[0040] The working process of this embodiment is as follows:

[0041] 1) The heating process involves using an electric heating particle device 5 to heat low-temperature solid particles into high-temperature solid particles. At this time, the low-temperature particle storage tank 4 is filled with low-temperature solid particles, while the high-temperature particle storage tank 6 is empty. During operation, the outlet valve of the high-temperature particle storage tank 6 is closed, and the outlet valves of the low-temperature particle storage tank 4 and the electric heating particle device 5 are opened. The electric heating particle device 5 is then activated, and the low-temperature solid particles flow from the low-temperature particle storage tank 4 into the electric heating particle device 5 by gravity, where they are heated into high-temperature solid particles and then flow into the high-temperature particle storage tank 6 for storage.

[0042] 2) The exothermic process involves using high-temperature particles to heat feedwater and obtain steam. During this process, the high-temperature particle storage tank 6 is filled with high-temperature solid particles, while the low-temperature particle storage tank 4 is empty. During operation, the outlet valve of the low-temperature particle storage tank 4 is closed, while the outlet valve of the high-temperature particle storage tank 6 and the particle outlet valve of the particle steam generation system 7 are opened. The feedwater pump 14 is then turned on, and feedwater 15 flows into the particle steam generation system 7. High-temperature solid particles flow from the high-temperature particle storage tank 6 into the particle steam generation system 7 by gravity, heating the feedwater 15 into steam 16, which then flows out. The high-temperature solid particles are cooled into low-temperature solid particles, which then flow into the low-temperature particle storage tank 4 for storage by gravity.

[0043] 3) Particle storage tank movement process. The low-temperature particle storage tank 4 is moved horizontally and vertically through the horizontal transport tank platform 8 and the vertical transport tank platform 9. The high-temperature particle storage tank 6 is moved horizontally through the horizontal transport tank platform 8 to ensure that the low-temperature particle storage tank 4 and the high-temperature particle storage tank 6 are in the appropriate positions during the heat charging and heat release processes.

[0044] To ensure continuous operation of the heat charging and heat release processes, multiple low-temperature particle storage tanks 4 and high-temperature particle storage tanks 6 can be arranged, and the particle storage tanks can be rationally allocated through horizontal transport tank platform 8 and vertical transport tank platform 9.

[0045] The solid particles involved in this invention have a particle size range of 0.2-2mm, and the types of solid particles can be ceramics, natural sand, etc. The operating temperature range is -40℃ to 1300℃.

[0046] This invention has illustrated its principles and implementation methods using specific examples. The descriptions of these embodiments are merely illustrative of the method and its core ideas; furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the principles of this invention. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. A system for heat storage using solid particles, characterized in that: This includes an electrically heated solid pellet system, a solid pellet heating water supply steam generation system, and a pellet storage tank transportation system; The electrically heated solid particle system includes a low-temperature particle storage tank, an electrically heated particle device, and a high-temperature particle storage tank arranged sequentially from top to bottom. The outlet of the low-temperature particle storage tank is connected to the inlet of the electrically heated particle device, and the outlet of the electrically heated particle device is connected to the inlet of the high-temperature particle storage tank. The solid particle heating water supply steam generation system includes a high-temperature particle storage tank, a particle steam generation system, and a low-temperature particle storage tank arranged sequentially from top to bottom. The outlet of the high-temperature particle storage tank is connected to the particle inlet of the particle steam generation system, and the particle outlet of the particle steam generation system is connected to the inlet of the low-temperature particle storage tank. The particle storage tank transportation system includes a horizontal tank transportation platform and a vertical tank transportation platform. The low-temperature particle storage tank and the high-temperature particle storage tank can move horizontally and vertically through the horizontal tank transportation platform and the vertical tank transportation platform. It also includes Platform 1, Platform 2, and Platform 3 arranged sequentially from bottom to top. The low-temperature particle storage tank, the electric heating particle device, and the high-temperature particle storage tank of the electric heating solid particle system are respectively arranged on one side of Platform 3, Platform 2, and Platform 1. The high-temperature particle storage tank, the particle steam generation system, and the low-temperature particle storage tank of the solid particle heating water supply steam generation system are respectively arranged on the other side of Platform 3, Platform 2, and Platform 1. A horizontal tank transport platform is arranged between the low-temperature particle storage tank and the high-temperature particle storage tank on Platform 1. A horizontal tank transport platform is also arranged between the high-temperature particle storage tank and the low-temperature particle storage tank on Platform 3. The vertical tank transport platform is arranged between the two horizontal tank transport platforms. Alternatively, it may include platforms 1, 2, 3, 4, and 5 arranged sequentially from bottom to top. The low-temperature particle storage tank, the electric heating particle device, and the high-temperature particle storage tank of the electrically heated solid particle system are respectively arranged on platforms 5, 4, and 3. The high-temperature particle storage tank, the particle steam generation system, and the low-temperature particle storage tank of the solid particle heating water supply steam generation system are respectively arranged on platforms 3, 2, and 1. A horizontal transport platform is provided between the two high-temperature particle storage tanks on platform 3. The low-temperature particle storage tank on platform 5 is connected to the low-temperature particle storage tank on platform 1 through the horizontal transport platform and the vertical transport platform.

2. The system for heat storage using solid particles according to claim 1, characterized in that: The cryogenic particle storage tank is a tank for storing solid particles at low temperatures. It has a heat preservation function, with the top opening serving as the feed inlet for solid particles and the bottom as the discharge outlet for solid particles. The discharge outlet is equipped with a cryogenic particle storage tank outlet valve.

3. The system for heat storage using solid particles according to claim 1, characterized in that: The electric heating particle device is a device that uses electrical energy to heat particles and has a heat preservation function. Its top opening is the feed port for solid particles, and its bottom opening is the discharge port for solid particles. The discharge port is equipped with an outlet valve for the electric heating particle device.

4. The system for heat storage using solid particles according to claim 1, characterized in that: The high-temperature particle storage tank is a tank for storing solid particles at high temperatures. It has a heat preservation function, with a top opening as the feed inlet for solid particles and a bottom opening as the discharge outlet for solid particles. The discharge outlet is equipped with a particle outlet valve for the high-temperature particle storage tank.

5. The system for heat storage using solid particles according to claim 1, characterized in that: The particle steam generation system is a device that can release the stored energy of particles into water to obtain steam. The discharge port of the particle steam generation system is equipped with a particle outlet valve.

6. The system for heat storage using solid particles according to claim 1, characterized in that: The particulate steam generating system is provided with a steam outlet and a water inlet on one side, and the water inlet is connected to the water supply via a water pump.

7. The system for heat storage using solid particles according to claim 1, characterized in that: The solid particles have a particle size range of 0.2-2mm, and the solid particles are ceramic or natural sand and gravel. The operating temperature range is -40℃ to 1300℃.

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