CN-121977376-A - Electrode type molten salt heating device

CN121977376ACN 121977376 ACN121977376 ACN 121977376ACN-121977376-A

Abstract

The application relates to the technical field of molten salt energy storage and provides an electrode type molten salt heating device which comprises a first molten salt tank, a second molten salt tank, a molten salt heating pipe, a third molten salt tank, a first conveying pipe, a second conveying pipe and a third conveying pipe, wherein the first molten salt tank is used for storing molten salt to be heated, the second molten salt tank is used for storing heated molten salt, the molten salt heating pipe is connected between the first molten salt tank and the second molten salt tank and is connected with a heating electrode, the third molten salt tank is used for mixing cold salt and heated molten salt to form molten salt to be heated, the first conveying pipe is communicated with the third molten salt tank and is used for conveying cold salt into the third molten salt tank, the second conveying pipe is communicated with the second molten salt tank and the third molten salt tank and is used for conveying heated molten salt into the third molten salt tank, and the third conveying pipe is communicated with the first molten salt tank and is used for conveying molten salt to be heated. The technical scheme of the application can effectively solve the problems of local overheating, molten salt over-temperature decomposition and high electrode corrosion rate in the related technology.

Inventors

XU JINLIANG
LIU CHAO
JI XIANBING
DONG XINYU
WANG YAN
YU XIONGJIANG

Assignees

北京怀柔实验室

Dates

Publication Date: 20260505
Application Date: 20260327

Claims (11)

1. An electrode type molten salt heating apparatus, comprising: A first molten salt pool (10) for storing molten salt to be heated; a second molten salt pool (20) for storing the heated molten salt; A molten salt heating pipe (30) connected between the first molten salt tank (10) and the second molten salt tank (20), the molten salt heating pipe (30) being connected with a heating electrode (40); A third molten salt pool (50) for mixing cold salt and the heated molten salt to form the molten salt to be heated; a first delivery pipe (61) communicating with the third molten salt bath (50) and for delivering the cold salt into the third molten salt bath (50); A second delivery pipe (62) communicating the second molten salt pool (20) and the third molten salt pool (50) and for delivering the heated molten salt into the third molten salt pool (50); and a third conveying pipe (63) which is communicated with the first molten salt pool (10) and the third molten salt pool (50) and is used for conveying the molten salt to be heated to the first molten salt pool (10).
2. The electrode molten salt heating apparatus according to claim 1, further comprising a mixer (70) provided in the third molten salt bath (50), the first delivery pipe (61) and the second delivery pipe (62) each being connected to the mixer (70).
3. The electrode type molten salt heating apparatus according to claim 1, wherein the molten salt heating pipe (30) has a molten salt inlet connected to the first molten salt bath (10) and a molten salt outlet connected to the second molten salt bath (20), the molten salt heating pipe (30) is disposed obliquely and the molten salt inlet is higher than the molten salt outlet.
4. An electrode molten salt heating apparatus according to claim 3, characterized in that the electrode molten salt heating apparatus comprises a plurality of the molten salt heating pipes (30), the plurality of molten salt heating pipes (30) being arranged at intervals in a height direction.
5. The electrode molten salt heating apparatus according to any one of claims 1 to 4, characterized in that the heating electrode (40) is connected with a high-voltage wire (01) and with a middle portion of the molten salt heating pipe (30), the first molten salt bath (10) is connected with a first zero wire connection (02), and the second molten salt bath (20) is connected with a second zero wire connection (03).
6. The electrode molten salt heating apparatus according to claim 5, characterized in that the molten salt heating pipe (30) includes a first insulating pipe (31), a first metal pipe (32), and a second insulating pipe (33) connected in this order in a direction from the first molten salt bath (10) to the second molten salt bath (20), the first metal pipe (32) being connected with the heating electrode (40).
7. The electrode molten salt heating apparatus according to claim 6, wherein, The molten salt heating pipe (30) further comprises a second metal pipe (34) connected between the first insulating pipe (31) and the first molten salt bath (10), and/or, The molten salt heating pipe (30) further comprises a third metal pipe (35) connected between the second insulating pipe (33) and the second molten salt bath (20).
8. The electrode molten salt heating apparatus according to claim 6, characterized in that a center line of the first insulating tube (31) and/or the second insulating tube (33) is a wavy line.
9. The electrode molten salt heating apparatus according to any one of claims 1 to 4, characterized in that the first molten salt bath (10) is located above the third molten salt bath (50), and the second molten salt bath (20) is located at a side of the first molten salt bath (10) and the third molten salt bath (50).
10. The electrode molten salt heating apparatus according to any one of claims 1 to 4, characterized in that the first molten salt bath (10) is located above the third molten salt bath (50), and the second molten salt bath (20) is of an annular structure and surrounds the outer circumferences of the first molten salt bath (10) and the third molten salt bath (50).
11. The electrode molten salt heating apparatus according to any one of claims 1 to 4, characterized in that a liquid level of the molten salt to be heated in the first molten salt bath (10) is higher than a liquid level of the heated molten salt in the second molten salt bath (20), and/or a liquid level of the heated molten salt in the second molten salt bath (20) is higher than a liquid level of the molten salt to be heated in the third molten salt bath (50).

Description

Electrode type molten salt heating device Technical Field The invention relates to the technical field of molten salt energy storage, in particular to an electrode type molten salt heating device. Background New power systems with gradually improved solar energy, wind energy and other new energy duty ratios are being built in China. The new energy has volatility and randomness, but the traditional thermal power generation has insufficient flexibility, and the power grid is insufficient in energy storage capacity, so that the new energy is abandoned, and the thermal power is forced to stop. Increasing the energy storage capacity is an important way to build new power systems. Compared with other energy storage technologies, the electric heating molten salt energy storage technology can realize large-scale long-time energy storage, is not limited by terrain factors, has high safety, low cost and low requirement on the quality of electric energy, can realize new energy power-saving consumption, improves thermal power flexibility and assists in grid frequency modulation, and has wide application prospects. Facing the above-mentioned demand, the electric heating molten salt device needs to have the following characteristics: (1) Wide adaptability, namely, wide range of voltage parameters (for example, 380V-35 kV) and power parameters (for example, 5 MW-50 MW) are required to be adapted for realizing power consumption and energy storage; (2) Safety, namely ensuring safe and stable operation, reducing the risks of electric arc and breakdown and reducing the risks of local overheating and high-temperature decomposition of molten salt; (3) The adjustability is that the electric heating device can realize power adjustment and operate under variable working conditions; (4) And (3) continuously outputting the hot molten salt with constant mass flow and temperature meeting the requirements in a certain period of time so as to realize continuous heat storage by matching with a storage system. The safety is that the electric conductivity of the fused salt is higher, so that the current density in the heated fused salt needs to be reduced to prevent local overheating during design, the fused salt overtemperature needs to be prevented in consideration of the high-temperature decomposition characteristic of the fused salt, the current density of an electrode needs to be reduced to inhibit corrosion. Therefore, it is needed to provide a design concept capable of reducing the current density so as to solve the problems of local overheating, molten salt super-temperature decomposition and rapid electrode corrosion rate. Disclosure of Invention The invention mainly aims to provide an electrode type molten salt heating device which is used for solving the problems of local overheating, molten salt over-temperature decomposition and high electrode corrosion rate in the related technology. In order to achieve the above purpose, the invention provides an electrode type molten salt heating device, which comprises a first molten salt tank, a second molten salt tank, a molten salt heating pipe, a third molten salt tank, a first conveying pipe, a second conveying pipe and a third conveying pipe, wherein the first molten salt tank is used for storing molten salt to be heated, the second molten salt tank is used for storing heated molten salt, the molten salt heating pipe is connected between the first molten salt tank and the second molten salt tank and is connected with a heating electrode, the third molten salt tank is used for mixing cold salt and heated molten salt to form molten salt to be heated, the first conveying pipe is communicated with the third molten salt tank and is used for conveying cold salt into the third molten salt tank, the second conveying pipe is communicated with the second molten salt tank and the third molten salt tank and is used for conveying heated molten salt into the third molten salt tank, and the third conveying pipe is communicated with the first molten salt tank and is used for conveying molten salt to be heated into the first molten salt tank. Further, the electrode type molten salt heating device further comprises a mixer arranged in the third molten salt pool, and the first conveying pipe and the second conveying pipe are connected with the mixer. Further, the molten salt heating pipe is provided with a molten salt inlet connected with the first molten salt pool and a molten salt outlet connected with the second molten salt pool, and the molten salt heating pipe is obliquely arranged and the molten salt inlet is higher than the molten salt outlet. Further, the electrode type molten salt heating device comprises a plurality of molten salt heating pipes which are arranged at intervals in the height direction. Further, the heating electrode is connected with the high-voltage wire and is connected with the middle part of the molten salt heating pipe, the first molten salt pool is connected with the firs