Isothermal fused salt energy storage tank device and fused salt energy storage system

Abstract

The invention relates to the technical field of energy storage, and discloses an isothermal fused salt energy storage tank device and a fused salt energy storage system.The isothermal fused salt energy storage tank device comprises a heliostat and a receiving tower, the receiving tower is fixedly connected with a hot salt tank through a pipeline, the hot salt tank is fixedly connected with a cold salt tank through a pipeline, and the cold salt tank is fixedly connected with a heat exchanger through a pipeline; the heat exchanger is fixedly connected with a pump body through a pipeline, the pump body is fixedly connected with a cooling tower through a pipeline, the cooling tower is fixedly connected with a power turbine through a pipeline, the power turbine is fixedly connected with a generator through a cable, and the generator is fixedly connected with a power grid system through a cable. The upper surface of the receiving tower is fixedly connected with a receiver, and the heliostat focuses reflected sunlight to the receiver. Fused salt has high specific heat capacity and can store a large amount of heat energy, the heat energy transfer efficiency is optimized through the design of the heat exchanger, and therefore the effect that it can be ensured that heat energy can be efficiently converted into electric energy can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an isothermal molten salt energy storage tank device and a molten salt energy storage system. Background Art

[0002] With the rapid development of renewable energy, the importance of energy storage technology in improving energy utilization efficiency and stability has become increasingly prominent.

[0003] Existing energy storage technologies have problems such as low energy density, low efficiency, and high operating costs, making it difficult to meet the needs of large-scale energy storage and efficient energy utilization. Therefore, providing an efficient and stable energy storage device and system has important technical significance and application value. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides an isothermal molten salt energy storage tank device and a molten salt energy storage system, which solve the problems of low energy density and low efficiency in the prior art energy storage technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: an isothermal molten salt energy storage tank device, including a heliostat and a receiving tower, the receiving tower is fixedly connected to a hot salt tank through a pipeline, the hot salt tank is fixedly connected to a cold salt tank through a pipeline, the cold salt tank is fixedly connected to a heat exchanger through a pipeline, the heat exchanger is fixedly connected to a pump body through a pipeline, the pump body is fixedly connected to a cooling tower through a pipeline, the cooling tower is fixedly connected to a power turbine through a pipeline, the power turbine is fixedly connected to a generator through a cable, the generator is fixedly connected to a power grid system through a cable, a receiver is fixedly connected to the upper surface of the receiving tower, and the heliostat focuses the reflected sunlight onto the receiver.

[0006] Preferably, the reflector of the heliostat is made of high-reflectivity silver-coated glass, and the base is made of galvanized steel. Each heliostat can achieve 360-degree rotation and 90-degree elevation adjustment, and an automatic tracking system combining GPS and photoelectric sensors is used to automatically track the sun and focus the light onto a receiver on the receiving tower.

[0007] Preferably, the receiving tower is made of reinforced concrete structure, with a receiver installed on the top. The interior of the receiver is made of a spiral tube made of nickel-based alloy, and the exterior is covered with a high-temperature resistant ceramic layer. The receiver receives sunlight reflected by the heliostat, converts light energy into heat energy, and heats the molten salt flowing through the receiver. The exterior of the receiver is provided with a water-cooling jacket.

[0008] Preferably, the interior of the hot salt tank is lined with three layers of insulation material - the inner layer is made of refractory bricks to provide preliminary thermal insulation, the middle layer is made of ceramic fiberboard, and the outer layer is made of vacuum insulation board to reduce heat conduction. The exterior of the hot salt tank is made of high temperature resistant steel.

[0009] Preferably, the interior of the cold salt tank is lined with three layers of high-efficiency heat-insulating materials: the inner layer is made of fiberglass board, the middle layer is made of polyurethane foam, and the outer layer is made of polystyrene foam board, and the exterior of the cold salt tank is made of high-temperature resistant steel.

[0010] Preferably, the heat exchanger is a shell and tube heat exchanger, and the heat transfer tube and the shell are both made of alloy steel. The heat exchanger allows high-temperature molten salt to flow through the tube to transfer heat energy to the working medium outside the tube.

[0011] Preferably, the pump body adopts a high-temperature centrifugal pump, and the pump body and impeller are both made of alloy steel. The pump body is used to maintain the circulation flow of molten salt in the system.

[0012] Preferably, the power turbine and generator adopt a steam-powered turbine motor set with a rated power of 100 megawatts, the turbine has a multi-stage blade design, and the generator is a synchronous generator equipped with a dual cooling system of water cooling and air cooling.

[0013] Preferably, the power grid system includes a transformer, a transmission line and a distribution equipment, and the power grid system is used to transmit the electric energy generated by the generator to the user end. The cooling tower uses water as a heat dissipation medium and discharges heat through a combination of natural ventilation and mechanical ventilation.

[0014] Preferably, the molten salt energy storage system of the isothermal molten salt energy storage tank device includes an energy absorption module, an energy storage module, an energy release module, an energy output module, and an energy recovery and circulation module. The energy absorption module concentrates the sunlight reflected by the heliostat onto the receiver at the top of the receiving tower. The nickel-based alloy spiral tube inside the receiver and the ceramic layer outside the receiver work together to convert the concentrated sunlight into thermal energy. The molten salt flowing through the receiver is heated to 500°C to 600°C, and the molten salt changes from solid to liquid and has high thermal energy. The energy storage module refers to the heated high-temperature molten salt flowing from the receiver into the hot salt tank to store thermal energy in the hot salt tank. The energy release module uses a pump to pump the high-temperature molten salt from the hot salt tank when the system needs to release energy. The tank is pumped into the heat exchanger, in which the high-temperature molten salt flows through the heat transfer tube of the shell and tube structure, transferring heat energy to the working fluid outside the tube. The working fluid is heated to a high temperature and high pressure state in the heat exchanger, and then transported to the power turbine through a pipeline. The energy output module enters the power turbine through the heated working fluid, drives the turbine to rotate, and the power turbine drives the generator to rotate. The generator converts mechanical energy into electrical energy, and the electrical energy generated by the generator is transmitted to the power grid system through a cable. After the energy recovery and circulation module releases heat energy in the heat exchanger, the temperature of the molten salt drops and is transported to the cold salt tank through a pipeline. The molten salt in the cold salt tank has a temperature of 250°C to 300°C, and is pumped back to the receiving tower through the pump body for reheating to realize a closed-loop cycle.

[0015] The present invention provides an isothermal molten salt energy storage tank device and a molten salt energy storage system. It has the following beneficial effects: 1. The present invention uses molten salt with high specific heat capacity to store a large amount of thermal energy, so that the system can achieve large-scale energy storage in a relatively small volume. Molten salt has good fluidity and heat transfer performance at high temperatures, and the design of the heat exchanger optimizes the thermal energy transfer efficiency, thereby ensuring that thermal energy can be efficiently converted into electrical energy.

[0016] 2. The present invention uses molten salt to have stable chemical properties at high temperatures, making it difficult to decompose and volatilize. The multi-layer thermal insulation materials in the energy storage tank ensure that heat energy can be effectively retained for a long time, reducing heat loss. The system can absorb solar energy during the day and release the stored heat energy at night or on cloudy days, providing stable power output and realizing all-weather operation, thereby achieving the effect of long-term energy storage.

[0017] 3. The present invention uses precise tracking and focusing technology of heliostats and receiving towers to maximize the utilization of solar energy, improve the efficiency of converting light energy into heat energy, use solar energy for energy storage and conversion, reduce dependence on fossil fuels, reduce carbon emissions, and help address climate change and environmental protection, thereby achieving the effect of efficient utilization of renewable energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a stereoscopic diagram of the isothermal molten salt energy storage tank device of the present invention; Figure 2 It is a schematic diagram of the molten salt energy storage system architecture of the isothermal molten salt energy storage tank device of the present invention; Figure 3 It is a schematic diagram of the energy absorption module architecture of the present invention; Figure 4 It is a schematic diagram of the energy storage module architecture of the present invention; Figure 5 It is a schematic diagram of the energy release module architecture of the present invention; Figure 6 It is a schematic diagram of the energy output module architecture of the present invention; Figure 7 It is a schematic diagram of the energy recovery and circulation module architecture of the present invention.

[0019] Among them, 1. Heliostat; 2. Receiving tower; 3. Hot salt tank; 4. Cold salt tank; 5. Receiver; 6. Heat exchanger; 7. Pump body; 8. Cooling tower; 9. Power turbine; 10. Generator; 11. Power grid system. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Please see attached Figure 1 - Attachment Figure 7 An embodiment of the present invention provides an isothermal molten salt energy storage tank device, including a heliostat 1 and a receiving tower 2. The receiving tower 2 is fixedly connected to a hot salt tank 3 through a pipeline, the hot salt tank 3 is fixedly connected to a cold salt tank 4 through a pipeline, the cold salt tank 4 is fixedly connected to a heat exchanger 6 through a pipeline, the heat exchanger 6 is fixedly connected to a pump body 7 through a pipeline, the pump body 7 is fixedly connected to a cooling tower 8 through a pipeline, the cooling tower 8 is fixedly connected to a power turbine 9 through a pipeline, the power turbine 9 is fixedly connected to a generator 10 through a cable, the generator 10 is fixedly connected to a power grid system 11 through a cable, a receiver 5 is fixedly connected to the upper surface of the receiving tower 2, and the heliostat 1 focuses the reflected sunlight onto the receiver 5.

[0022] The reflector of the heliostat 1 is made of high-reflectivity silver-coated glass, and the base is made of galvanized steel. Each heliostat 1 can achieve 360-degree rotation and 90-degree elevation adjustment. It uses an automatic tracking system combining GPS and photoelectric sensors to automatically track the sun and focus the light onto the receiver 5 on the receiving tower 2. Specifically, 5000 heliostats 1 are arranged in a 50-hectare solar collector field, and each heliostat 1 has an area of ​​10 square meters.

[0023] The receiving tower 2 is a reinforced concrete structure, with a receiver 5 installed on the top. The inside of the receiver 5 is a spiral tube made of a nickel-based alloy, and the outside is covered with a high-temperature resistant ceramic layer. The receiver 5 receives the sunlight reflected by the heliostat 1, converts the light energy into heat energy, and heats the molten salt flowing through the receiver 5. The outside of the receiver 5 is equipped with a water-cooling jacket; Specifically, the receiving tower 2 is 120 meters high and adopts a reinforced concrete structure. A receiver 5 with a diameter of 5 meters and a height of 10 meters is installed on the top.

[0024] The interior of the hot salt tank 3 is lined with three layers of insulation materials - the inner layer is made of refractory bricks to provide preliminary thermal insulation, the middle layer is made of ceramic fiberboard, the outer layer is made of vacuum insulation board to reduce heat conduction, and the exterior of the hot salt tank 3 is made of high temperature resistant steel; Specifically, the hot salt tank 3 has a capacity of 10,000 cubic meters, a diameter of 20 meters and a height of 30 meters.

[0025] The interior of the cold salt tank 4 is lined with three layers of high-efficiency heat-insulating materials: the inner layer is made of fiberglass board, the middle layer is made of polyurethane foam, the outer layer is made of polystyrene foam board, and the exterior of the cold salt tank 4 is made of high-temperature resistant steel; Specifically, the cold salt tank 4 has a capacity of 10,000 cubic meters, a diameter of 20 meters and a height of 30 meters.

[0026] The heat exchanger 6 adopts a shell and tube heat exchanger 6, and the heat transfer tube and the shell are made of alloy steel. The heat exchanger 6 allows the high-temperature molten salt to flow through the tube and transfers heat energy to the working medium outside the tube; Specifically, a shell and tube heat exchanger 6 is used, with a tube length of 100 meters, a diameter of 1 meter, and a total of 200 heat transfer tubes.

[0027] The pump body 7 adopts a high-temperature centrifugal pump. The pump body 7 and the impeller are both made of alloy steel. The pump body 7 is used to maintain the circulation flow of molten salt in the system; Specifically, the high temperature centrifugal pump has a flow rate of 200 cubic meters per hour and a head of 150 meters.

[0028] The power turbine 9 and the generator 10 adopt a steam-powered turbine generator set with a rated power of 100 MW. The turbine is designed with multi-stage blades. The generator 10 is a synchronous generator 10 equipped with a dual cooling system of water cooling and air cooling.

[0029] The power grid system 11 includes a transformer, a transmission line and a distribution device. The power grid system 11 is used to transmit the electric energy generated by the generator 10 to the user end. The cooling tower 8 uses water as a heat dissipation medium and discharges heat through a combination of natural ventilation and mechanical ventilation.

[0030] The molten salt energy storage system of the isothermal molten salt energy storage tank device includes an energy absorption module, an energy storage module, an energy release module, an energy output module, and an energy recovery and circulation module. The energy absorption module concentrates the sunlight reflected by the heliostat 1 onto the receiver 5 on the top of the receiving tower 2. The nickel-based alloy spiral tube inside the receiver 5 and the ceramic layer outside the receiver 5 work together to convert the concentrated sunlight into thermal energy. The molten salt flowing through the receiver 5 is heated to 500°C to 600°C, and the molten salt changes from solid to liquid and has high thermal energy. The energy storage module refers to the heated high-temperature molten salt flowing from the receiver 5 into the hot salt tank 3 to store thermal energy in the hot salt tank 3. When the system needs to release energy, the energy release module pumps the high-temperature molten salt from the hot salt tank 3 into the heat exchanger 6 through the pump body 7. In the heat exchanger 6, the high-temperature molten salt flows through the heat transfer tube of the shell and tube structure, transferring heat energy to the working medium outside the tube. The working medium is heated to a high temperature and high pressure state in the heat exchanger 6, and then transported to the power turbine 9 through a pipeline. The energy output module enters the power turbine 9 through the heated working medium, driving the turbine to rotate. The power turbine 9 drives the generator 10 to rotate. The generator 10 converts mechanical energy into electrical energy. The electrical energy generated by the generator 10 is transmitted to the power grid system 11 through a cable. After the energy recovery and circulation module releases heat energy in the heat exchanger 6, the temperature of the molten salt drops and is transported to the cold salt tank 4 through a pipeline. The temperature of the molten salt in the cold salt tank 4 is 250°C to 300°C, and it is pumped back to the receiving tower 2 through the pump body 7 for reheating to realize a closed-loop circulation.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An isothermal molten salt energy storage tank device, comprising a heliostat (1) and a receiving tower (2), characterized in that: The receiving tower (2) is fixedly connected to a hot salt tank (3) via a pipeline, the hot salt tank (3) is fixedly connected to a cold salt tank (4) via a pipeline, the cold salt tank (4) is fixedly connected to a heat exchanger (6) via a pipeline, the heat exchanger (6) is fixedly connected to a pump body (7) via a pipeline, the pump body (7) is fixedly connected to a cooling tower (8) via a pipeline, the cooling tower (8) is fixedly connected to a power turbine (9) via a pipeline, the power turbine (9) is fixedly connected to a generator (10) via a cable, the generator (10) is fixedly connected to a power grid system (11) via a cable, a receiver (5) is fixedly connected to the upper surface of the receiving tower (2), and the heliostat (1) focuses reflected sunlight onto the receiver (5).

2. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The reflector of the heliostat (1) is made of high-reflectivity silver-coated glass, and the base is made of galvanized steel. Each heliostat (1) can achieve 360-degree rotation and 90-degree elevation adjustment, and uses an automatic tracking system combining GPS and photoelectric sensors to automatically track the sun and focus light onto a receiver (5) on a receiving tower (2).

3. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The receiving tower (2) is of reinforced concrete structure, with a receiver (5) installed on the top. The interior of the receiver (5) is made of a spiral tube made of a nickel-based alloy, and the exterior is covered with a high-temperature resistant ceramic layer. The receiver (5) receives sunlight reflected by the heliostat (1), converts light energy into heat energy, and heats the molten salt flowing through the receiver (5). The exterior of the receiver (5) is provided with a water-cooling jacket.

4. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The interior of the hot salt tank (3) is lined with three layers of thermal insulation materials: the inner layer is made of refractory bricks to provide preliminary thermal insulation, the middle layer is made of ceramic fiberboard, and the outer layer is made of vacuum insulation board to reduce heat conduction. The exterior of the hot salt tank (3) is made of high temperature resistant steel.

5. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The interior of the cold salt tank (4) is lined with three layers of high-efficiency heat-insulating materials: the inner layer is made of glass fiber board, the middle layer is made of polyurethane foam, and the outer layer is made of polystyrene foam board. The exterior of the cold salt tank (4) is made of high-temperature resistant steel.

6. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The heat exchanger (6) is a shell and tube heat exchanger (6), wherein the heat transfer tube and the shell are both made of alloy steel. The heat exchanger (6) allows high-temperature molten salt to flow through the tubes to transfer heat energy to the working medium outside the tubes.

7. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The pump body (7) is a high-temperature centrifugal pump, and the pump body (7) and the impeller are both made of alloy steel. The pump body (7) is used to maintain the circulation flow of molten salt in the system.

8. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The power turbine (9) and the generator (10) adopt a steam-powered turbine motor set with a rated power of 100 megawatts. The turbine has a multi-stage blade design, and the generator (10) is a synchronous generator (10) equipped with a dual cooling system of water cooling and air cooling.

9. The isothermal molten salt energy storage tank device according to claim 1, characterized in that: The power grid system (11) comprises a transformer, a transmission line and a power distribution device. The power grid system (11) is used to transmit the electric energy generated by the generator (10) to the user end. The cooling tower (8) uses water as a heat dissipation medium and discharges heat through a combination of natural ventilation and mechanical ventilation.

10. A molten salt energy storage system of an isothermal molten salt energy storage tank device, according to any one of the isothermal molten salt energy storage tank devices according to claim 1-9, characterized in that: The invention comprises an energy absorption module, an energy storage module, an energy release module, an energy output module, and an energy recovery and circulation module. The energy absorption module concentrates the sunlight reflected by the heliostat (1) onto a receiver (5) at the top of the receiving tower (2). The nickel-based alloy spiral tube inside the receiver (5) and the ceramic layer outside the receiver (5) work together to convert the concentrated sunlight into thermal energy. The molten salt flowing through the receiver (5) is heated to 500° C. to 600° C., and the molten salt changes from a solid state to a liquid state and has high thermal energy. The energy storage module refers to the heated high-temperature molten salt flowing from the receiver (5) into the hot salt tank (3) to store thermal energy in the hot salt tank (3). The energy release module is configured such that when the system needs to release energy, a pump body (7) pumps the high-temperature molten salt from the hot salt tank (3) into a heat exchanger (6). In the heat exchanger (6), the high-temperature molten salt is heated to 500° C. to 600° C., and the molten salt changes from a solid state to a liquid state and has high thermal energy. The high-temperature molten salt flows through the heat transfer tube of the shell-and-tube structure, transferring heat energy to the working fluid outside the tube. The working fluid is heated to a high-temperature and high-pressure state in the heat exchanger (6), and then transported to the power turbine (9) through a pipeline. The energy output module enters the power turbine (9) through the heated working fluid, driving the turbine to rotate. The power turbine (9) drives the generator (10) to rotate. The generator (10) converts mechanical energy into electrical energy. The electrical energy generated by the generator (10) is transported to the power grid system (11) through a cable. After the energy recovery and circulation module releases heat energy in the heat exchanger (6), the temperature of the molten salt drops and is transported to the cold salt tank (4) through a pipeline. The temperature of the molten salt in the cold salt tank (4) is 250° C. to 300° C., and the molten salt is pumped back to the receiving tower (2) through a pump body (7) for reheating, thereby realizing a closed-loop circulation.

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