Electric heating device and method for fused salt storage tank

Abstract

The invention discloses a fused salt storage tank electric heating device and method, the fused salt storage tank electric heating device comprises a tank body, an electric heating module, an extraction pipe, a return pipe, a fused salt pump and a heat exchange pipe, the tank body is used for storing fused salt; the electric heating module is used for heating the fused salt in the tank body, when the temperature of the fused salt is lower than a threshold value, the second electric control valve is closed to stop heat exchange and power generation of the heat exchange pipe, and the first electric control valve and the electric heating module are started to heat the fused salt. The temperature of the molten salt in the tank can be more uniform, the local overheating phenomenon is reduced, the risks of molten salt decomposition and equipment loss are reduced, the service life of equipment is prolonged, the operation stability of the equipment is improved, the dynamic thermal load change in the molten salt phase change process can be effectively adapted, the energy conversion efficiency is improved, and the abnormal condition of the molten salt temperature can be found in time; and corresponding measures are taken, so that the safety problem caused by abnormal temperature is avoided, the safety of the system is enhanced, a molten salt flowing dead zone can be reduced, and the heat exchange efficiency is improved.

Claims

1. An electric heating device for a molten salt storage tank, characterized in that: include: A tank body having a molten salt inlet, a molten salt outlet and an exhaust port, and the tank body is used to store the molten salt; an electric heating module, the electric heating module being arranged on the tank body and being used for heating the molten salt in the tank body; An extraction pipe, a return pipe and a molten salt pump, wherein the two ends of the extraction pipe are respectively connected to the molten salt outlet and the inlet of the molten salt pump, the two ends of the return pipe are respectively connected to the molten salt inlet and the outlet of the molten salt pump, and the return pipe is provided with a first electrically controlled valve; A heat exchange tube, one end of which is connected to the return pipe, and the other end of which is connected to the tank body. The heat exchange tube is used for heat exchange power generation. A second electrically controlled valve is provided on the heat exchange tube. When the temperature of the molten salt is lower than a threshold value, the second electrically controlled valve is closed to stop the heat exchange power generation by the heat exchange tube, and the first electrically controlled valve and the electric heating module are opened to heat the molten salt.

2. The molten salt storage tank electric heating device according to claim 1, characterized in that: The extraction pipe is provided with a flow rate sensor and a temperature sensor, and the molten salt storage tank electric heating device includes a controller, which is respectively controlled and connected to the electric heating module, the molten salt pump, the first electrically controlled valve, the second electrically controlled valve, the flow rate sensor and the temperature sensor; When the temperature of the molten salt is lower than the threshold, the controller controls the closing of the second electrically controlled valve and the opening of the first electrically controlled valve and the electric heating module. The controller dynamically adjusts the opening and closing of the first electrically controlled valve, the speed of the molten salt pump and the heating power of the electric heating module based on the PID algorithm to make the molten salt temperature reach the threshold.

3. The molten salt storage tank electric heating device according to claim 2, characterized in that: A plurality of diverter plates are provided in the tank body, and the plurality of diverter plates are divided into a plurality of diverter groups. The plurality of diverter groups are arranged at intervals along the flow direction of the molten salt, and each of the diverter groups includes multiple layers of diverter plates.

4. The molten salt storage tank electric heating device according to claim 3, characterized in that: The diverter plate is a wave plate, and the wave plate bends and extends along the flow direction of the molten salt.

5. The molten salt storage tank electric heating device according to claim 2, characterized in that: A partition plate is provided in the tank body, which divides the chamber of the tank body into a first chamber and a second chamber. A flow channel connecting the first chamber and the second chamber is defined between the partition plate and the tank body. The molten salt inlet is connected to the first chamber, and the molten salt outlet is connected to the second chamber.

6. The electric heating device for molten salt storage tank according to claim 3, characterized in that: The flow channel is arranged adjacent to the top of the tank body, and the molten salt inlet is arranged adjacent to the bottom of the tank body.

7. The electric heating device for molten salt storage tank according to claim 2, characterized in that: The electric heating module includes a plurality of heating tubes, and the plurality of heating tubes extend to both ends of the tank body along the flow direction of the molten salt.

8. A method for electrically heating a molten salt storage tank, characterized in that: The method is based on the molten salt storage tank electric heating device according to any one of claims 2 to 7, comprising: The PID algorithm implements the following threshold control strategy: When the detection temperature T meets T <T s -ΔT th The second electrically controlled valve is closed when T s is the set temperature, ΔT th is the preset temperature threshold; When the real-time traffic Q satisfies Q s -ΔQ th When the speed adjustment of the molten salt pump satisfies:​ Δn=K p (Q s -Q)+αQ s Among them, Q s is the set flow rate, ΔQ th is the flow deviation threshold, K p is the proportional coefficient, α is the compensation factor; When |TT s |>ΔT lim When , the heating power adjustment rate of the molten salt pump is increased to β times of the reference rate, where ΔT lim Adjust the temperature deviation limit for power acceleration.

9. The electric heating method for a molten salt storage tank according to claim 8, characterized in that: The parameters of the controller are based on the temperature deviation ΔT=|TT s |Partition adjustment: Where ΔT<ΔT2 is the preset temperature deviation classification threshold, K p ,K i ,K d , is the PID parameter group of the corresponding partition.

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