Spherical tank system for high-capacity fused salt energy storage

Abstract

The spherical tank system comprises a spherical tank module, a heat absorption module and a light condensation module, the spherical tank module comprises at least one spherical tank body, the at least one spherical tank body is connected in parallel, the outer end of the spherical tank module is connected with a nitrogen preheating module, a fused salt heat exchange module and a salt dredging module, and the nitrogen preheating module is connected with the fused salt heat exchange module. The spherical tank module comprises a nitrogen pipeline used for being communicated with nitrogen, a fused salt pump located at the upper end of a spherical tank body and a fused salt mother pipe connected with the spherical tank body, the nitrogen preheating module comprises a circulating fan, an air electric heater, a circulating pipeline and a nitrogen valve, and the fused salt heat exchange module comprises a fused salt heat exchanger and a heat exchanger valve. The condensation module is used for absorbing solar energy and converting the solar energy into heat energy. The molten salt mother pipe comprises a low-temperature molten salt mother pipe and a high-temperature molten salt mother pipe, and the output end of the low-temperature molten salt mother pipe is connected with the absorption module. On the premise that the heat loss is effectively reduced, the safety of the system can be improved, and the one-time investment of the system can be greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage spherical tanks, and in particular to a spherical tank system for large-capacity molten salt energy storage. Background Art

[0002] The large-capacity molten salt energy storage spherical tank system is an advanced thermal energy storage technology that uses molten salt as a storage medium. It can store energy in conditions where the sun is not shining or the wind is not blowing, and release the energy when needed. This system typically consists of one or more spherical tanks filled with molten salt, which can store large amounts of thermal energy at high temperatures.

[0003] Large-capacity molten salt energy storage spherical tanks have the following technical features:

[0004] High-temperature stable output: The molten salt energy storage system can stably output high-temperature steam, significantly improving energy utilization efficiency;

[0005] Energy saving and environmental protection: By storing molten salt heated by electricity during off-peak hours and then releasing the energy during peak hours, it helps balance the grid load, improve energy efficiency, and reduce energy waste;

[0006] Safety: Spherical tank systems are usually equipped with multiple safety protection measures, such as dual active temperature compensation systems, to reduce temperature fluctuations, extend the life of the spherical tank, and ensure that it can be started at any time in the event of a long shutdown;

[0007] Economic benefits: The spherical tank system can adopt the technology of multiple tanks in series to isolate nitrogen and store both hot and cold at the same time. Compared with traditional storage tanks, it can save steel consumption and floor space, and reduce equipment and initial construction investment;

[0008] Large-capacity molten salt energy storage spherical tanks are used in new energy consumption: the spherical tank system can help consume renewable energy such as wind power and solar energy and improve its utilization rate; it is used in industrial energy storage: in the industrial production process, the spherical tank system can be used as a thermal energy storage facility to store excess thermal energy for use when needed; it is used in peak-valley power regulation: by storing electrical energy during low-peak periods and releasing energy during peak periods, the spherical tank system helps to regulate the grid load and improve the stability of the power system; it is used in steam power generation: the spherical tank system can be used in steam power stations to store thermal energy and convert it into electrical energy when needed, thereby improving power generation efficiency.

[0009] In the prior art, during the use of the energy storage spherical tank:

[0010] (1) The basic design of the tank bottom insulation is difficult. In addition to supporting the mass of the storage tank and the molten salt inside, it is also used to reduce the heat loss at the tank bottom. Design errors can easily cause the equipment foundation to sink. If the sinking is uneven, the tank body will be locally deformed and torn, which may lead to molten salt leakage accidents.

[0011] (2) The energy storage molten salt spherical tank has problems such as complex form, high construction difficulty and high cost;

[0012] (3) When a large-scale molten salt energy storage system is used, hot tanks and cold tanks need to be paired, that is, a large number of high-temperature storage tanks and the same number of low-temperature storage tanks are configured;

[0013] (4) The heat storage system has problems such as a large number of storage tanks, a large floor area, and a large one-time investment;

[0014] Therefore, we made improvements to this and proposed a spherical tank system for large-capacity molten salt energy storage. Utility Model Content

[0015] The purpose of the utility model is to improve the safety of the system and significantly reduce the one-time investment of the system in view of the current design of the energy storage spherical tank while effectively reducing the heat loss.

[0016] In order to achieve the above-mentioned purpose of the utility model, the utility model provides the following technical solutions:

[0017] A spherical tank system is used for large-capacity molten salt energy storage to improve the above problems.

[0018] The specific application is as follows:

[0019] A spherical tank system for large-capacity molten salt energy storage includes a spherical tank module, a heat absorption module and a focusing module. The spherical tank module includes at least one spherical tank body, and at least one spherical tank body is connected in parallel. The outer end of the spherical tank module is connected to a nitrogen preheating module, a molten salt heat exchange module and a salt-repelling module. The spherical tank module includes a nitrogen pipeline for connecting nitrogen, a molten salt pump located at the upper end of the spherical tank body and a molten salt main pipe connected to the spherical tank body. The nitrogen preheating module includes a circulating fan, an electric air heater, a circulating pipeline and a nitrogen valve. The molten salt heat exchange module includes a molten salt heat exchanger and a heat exchanger valve.

[0020] As a preferred technical solution of the present application, the concentrating module is used to absorb solar energy and convert it into thermal energy through the heat absorption module.

[0021] As the preferred technical solution of this application, the molten salt mother pipe includes a low-temperature molten salt mother pipe and a high-temperature molten salt mother pipe. The output end of the low-temperature molten salt mother pipe is connected to the absorption module, and the input end of the low-temperature molten salt mother pipe is connected to the molten salt heat exchanger or the salt-removing module.

[0022] As the preferred technical solution of this application, the high-temperature molten salt main pipe connects the molten salt heat exchanger and the spherical tank module, the input end of the high-temperature molten salt main pipe is connected to the heat absorption module, and the output end of the high-temperature molten salt main pipe is connected to the spherical tank module or the salt-dissipating module.

[0023] As the preferred technical solution of the present application, an electric heating module is wound along the longitude and latitude lines inside the spherical tank module for electric heating in standby mode.

[0024] As the preferred technical solution of this application, a chain breaking module and a fault module are provided in the spherical tank module. The chain breaking module is used to flexibly cut the faulty spherical tank body out of the operating array, and the fault module is used to alarm the faulty spherical tank body.

[0025] As the preferred technical solution of this application, the nitrogen preheating module is used for the rapid start-up of the molten salt mother pipe.

[0026] As the preferred technical solution of this application, a salt-removing tank is provided in the salt-removing module.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the scheme of this application:

[0029] 1. The optimized spherical tank is used as the molten salt storage container, which has the advantages of uniform force, strong pressure resistance, minimum surface area under the same volume, minimum steel consumption, less heat loss, and good thermal insulation;

[0030] 2. Compared with vertical columnar tanks, it has the characteristics of uniform force, good elasticity, ability to withstand thermal expansion and deformation, less foundation engineering, less heat loss, simple repair and maintenance, etc., which can effectively reduce the cost;

[0031] 3. Using a spherical tank as the molten salt storage container and the bottom as the molten salt outlet can effectively reduce the molten salt residue, maximize the utilization of molten salt during the module energy storage and release cycle, and reduce the initial amount of molten salt in the module;

[0032] 4. The spherical tank of this application can be used as both a high-temperature molten salt storage tank and a low-temperature molten salt storage tank, which can significantly reduce the number of storage tanks, has a high energy storage density and capacity, and greatly reduces the one-time investment and floor space.

[0033] 5. When a spherical tank fails, this module can flexibly switch the faulty spherical tank out of the operating array, and evacuate the molten salt in the faulty spherical tank to the salt drainage tank through the salt drainage module for separate maintenance and repair, without affecting the operation of the entire module;

[0034] 6. Continuously switch between heat storage and heat release work processes; during the conversion process, use nitrogen to seal and isolate the high-temperature molten salt spherical tank and the low-temperature molten salt spherical tank to prevent the molten salt from contacting with the air and causing oxidation reaction.

[0035] Thus ensuring the long-term stable operation of the module;

[0036] 7. A nitrogen preheating module is installed to preheat the entire spherical tank module, pipelines, and pump group, reducing the instantaneous thermal stress of molten salt injection and preventing molten salt solidification and blockage. This enables rapid startup of the molten salt storage module. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The spherical tank system for large-capacity molten salt energy storage provided in this application is a system diagram using a solar thermal absorption module as an illustration. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them.

[0039] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative effort are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other unless there is a conflict.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0041] like Figure 1 As shown, this embodiment proposes a spherical tank system for large-capacity molten salt energy storage, including a spherical tank module, a heat absorption module and a focusing module. The spherical tank module includes at least one spherical tank body, and at least one spherical tank body is connected in parallel. The outer end of the spherical tank module is connected to a nitrogen preheating module, a molten salt heat exchange module and a salt-repelling module. The spherical tank module includes a nitrogen pipeline for connecting nitrogen, a molten salt pump located at the upper end of the spherical tank body and a molten salt main pipe connected to the spherical tank body. The nitrogen preheating module includes a circulating fan, an electric air heater, a circulating pipeline and a nitrogen valve. The molten salt heat exchange module includes a molten salt heat exchanger and a heat exchanger valve.

[0042] The concentrating module is used to absorb solar energy and convert it into thermal energy through the heat absorption module.

[0043] The molten salt mother pipe includes a low-temperature molten salt mother pipe and a high-temperature molten salt mother pipe. The output end of the low-temperature molten salt mother pipe is connected to the absorption module, and the input end of the low-temperature molten salt mother pipe is connected to the molten salt heat exchanger or the salt-removing module.

[0044] The high-temperature molten salt main pipe is connected to the molten salt heat exchanger and the spherical tank module, the input end of the high-temperature molten salt main pipe is connected to the heat absorption module, and the output end of the high-temperature molten salt main pipe is connected to the spherical tank module or the salt-dissipating module.

[0045] Compared to conventional thermal storage modules, which require separate paired cold and hot tanks, the spherical tanks in this application serve as both high-temperature and low-temperature molten salt storage tanks, significantly reducing the number of tanks and achieving extremely high energy storage density and capacity. (The energy storage capacity of conventional modules is n / 2; the energy storage capacity of this application module is n-1 (n: number of tanks)), significantly reducing both initial investment and floor space.

[0046] The heat storage and heat release processes are continuously switched; during the switching process, nitrogen is used to seal and isolate the high-temperature molten salt spherical tank and the low-temperature molten salt spherical tank to prevent the molten salt from contacting with the air and causing oxidation reactions. This ensures long-term stable operation of the module.

[0047] An electric heating module is wound along the longitude and latitude lines inside the spherical tank module for electric heating in standby mode.

[0048] The spherical tank module is equipped with a chain breaking module and a fault module. The chain breaking module is used to flexibly cut the faulty spherical tank out of the operating array, and the fault module is used to alarm the faulty spherical tank. When a spherical tank fails, the faulty spherical tank can be flexibly switched out of the operating array, and the molten salt in the faulty spherical tank can be evacuated to the salt drainage tank through the salt drainage module and then maintained and repaired separately without affecting the operation of the entire module.

[0049] The nitrogen preheating module is used for the rapid start-up of the molten salt main pipe.

[0050] A salt removal tank is provided in the salt removal module.

[0051] When using this application:

[0052] During the module startup phase, nitrogen is first delivered to spherical tank 1. After reaching the set pressure, the nitrogen circulation fan and air electric heater are turned on. Through the circulation heating method, spherical tank 1 is heated to the set preheating temperature. Then, low-temperature molten salt is injected into spherical tank 1. At the same time, the nitrogen in spherical tank 1 is discharged into spherical tank 2 through the nitrogen valve switch. The circulation fan and air electric heater are turned on. Through the circulation heating method, spherical tank 2 is heated to the set preheating temperature. Then, low-temperature molten salt is injected into spherical tank 2. In this way, spherical tank 3 is also preheated and molten salt is injected. Nitrogen is then gathered in spherical tank 4. At this point, the module is ready for startup.

[0053] During the module energy storage phase, the low-temperature molten salt in the spherical tank 1 is transported to the heat absorption module through the molten salt pump to absorb heat (depending on the application scenario, different heating methods are used, such as Figure 1The solar thermal absorption module (illustrated here) absorbs heat and raises the temperature to the rated value. The heat is then fed into spherical tank 4, which stores nitrogen. The nitrogen is discharged from the top into tank 1. Once all the low-temperature molten salt in tank 1 has been discharged, it is converted into a nitrogen tank. Tank 4, which previously stored nitrogen, is then converted into an energy storage tank for high-temperature molten salt. This conversion continues until tanks 2, 3, and 4 store high-temperature molten salt, while tank 1 stores nitrogen. This completes the energy storage process.

[0054] During the module energy release phase, the high-temperature molten salt in spherical tank 2 is transported to the molten salt heat exchange module through a molten salt pump for heat exchange (different heat exchange methods correspond to different application scenarios). After heat exchange, it is converted into low-temperature molten salt and then input into spherical tank 1 for storing nitrogen. Nitrogen is discharged from the top to spherical tank 2. After all the high-temperature molten salt in spherical tank 2 is output, it is converted into a spherical tank for storing nitrogen, and spherical tank 1, which originally stored nitrogen, is converted into a spherical tank for storing low-temperature molten salt. The conversion is carried out in sequence until all the high-temperature molten salt stored in the spherical tanks has completed heat release and converted into low-temperature molten salt, and the heat release process ends. At this time, low-temperature molten salt is stored in spherical tanks 1, 2, and 3, and nitrogen is stored in spherical tank 4.

[0055] Electric heating modules are installed along the warp and weft lines of each spherical tank. When the module is in a long-term standby state, the electric heating system can be turned on to supplement the long-term heat dissipation loss and ensure that the module is in a hot standby state and can be started at any time.

[0056] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention are included in the scope of the claims of the present invention.

Claims

1. A spherical tank system for large-capacity molten salt energy storage, comprising a spherical tank module, a heat absorption module and a light concentrating module, characterized in that: The spherical tank module includes at least one spherical tank body, and at least one spherical tank body is connected in parallel. The outer end of the spherical tank module is connected to a nitrogen preheating module, a molten salt heat exchange module and a salt-repelling module. The spherical tank module includes a nitrogen pipeline for connecting nitrogen, a molten salt pump located at the upper end of the spherical tank body and a molten salt main pipe connected to the spherical tank body. The nitrogen preheating module includes a circulating fan, an electric air heater, a circulating pipeline and a nitrogen valve. The molten salt heat exchange module includes a molten salt heat exchanger and a heat exchanger valve.

2. A spherical tank system for large-capacity molten salt energy storage according to claim 1, characterized in that: The concentrating module is used to absorb solar energy and convert it into thermal energy through the heat absorption module.

3. A spherical tank system for large-capacity molten salt energy storage according to claim 1, characterized in that: The molten salt mother pipe includes a low-temperature molten salt mother pipe and a high-temperature molten salt mother pipe. The output end of the low-temperature molten salt mother pipe is connected to the absorption module, and the input end of the low-temperature molten salt mother pipe is connected to the molten salt heat exchanger or the salt-removing module.

4. A spherical tank system for large-capacity molten salt energy storage according to claim 1, characterized in that: The high-temperature molten salt main pipe connects the molten salt heat exchanger and the spherical tank module, the input end of the high-temperature molten salt main pipe is connected to the heat absorption module, and the output end of the high-temperature molten salt main pipe is connected to the spherical tank module or the salt-dissipating module.

5. The spherical tank system for large-capacity molten salt energy storage according to claim 1 is characterized in that: An electric heating module is wound along the longitude and latitude lines in the spherical tank module for electric heating in a standby state.

6. The spherical tank system for large-capacity molten salt energy storage according to claim 1 is characterized in that: The spherical tank module is provided with a chain breaking module and a fault module. The chain breaking module is used to flexibly cut the faulty spherical tank body out of the running array, and the fault module is used to alarm the faulty spherical tank body.

7. The spherical tank system for large-capacity molten salt energy storage according to claim 1 is characterized in that: The nitrogen preheating module is used for rapid startup of the molten salt mother pipe.

8. The spherical tank system for large-capacity molten salt energy storage according to claim 1 is characterized in that: A salt-removing tank is provided in the salt-removing module.

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