CN-119119973-B - Ternary chloride heat storage material with heat storage performance and corrosiveness and preparation method thereof

CN119119973BCN 119119973 BCN119119973 BCN 119119973BCN-119119973-B

Abstract

The invention discloses a ternary chloride heat storage material with heat storage performance and corrosiveness and a preparation method thereof, the heat storage material is obtained by adding metal and metal oxide nano particles into ternary molten salt with components of sodium chloride, potassium chloride and magnesium chloride. The heat storage performance of the ternary molten salt is improved by means of the interaction between the nano particles and the chloride salt, meanwhile, a corrosion-resistant layer is formed or corrosive components are consumed by means of the interaction between the nano particles and the corrosion surface of the alloy pipeline, automatic corrosion prevention is achieved, and new nano particles can be replenished in the heat storage tank at any time according to the consumption condition of the nano particles. The ternary chloride heat storage material prepared by the method has the characteristics of excellent heat storage performance, strong corrosion resistance, low price and the like, is simple and efficient, has low cost and convenient operation, effectively overcomes the defects of poor thermal performance, strong corrosiveness and the like of the traditional molten chloride, and can be used as a high-temperature heat storage/transfer medium of a concentrating solar power generation system.

Inventors

TAO YUBING
HAO SHUAI
WANG SIQI
HE YUAN
XIN XU

Assignees

西安交通大学

Dates

Publication Date: 20260505
Application Date: 20240909

Claims (7)

1. The ternary chloride salt heat storage material is characterized in that nano particles for strengthening heat storage performance and weakening corrosion performance are added into ternary mixed molten salt of sodium chloride, potassium chloride and magnesium chloride, and the ternary chloride salt heat storage material is prepared by a melt blending method; 14.0-18.0% of sodium chloride, 36.0-40.0% of potassium chloride and 46.0-50.0% of magnesium chloride according to the mass percentage content in the ternary mixed molten salt; the nano particles are metal Mg, and the addition amount of the nano particles is 8.0% -10.0% of the total mass of the ternary chloride heat storage material.
2. The ternary chloride heat storage material with heat storage performance and corrosiveness according to claim 1, wherein the particle size of the nanoparticles is 50.0-100.0 nm.
3. The ternary chloride heat storage material with heat storage performance and corrosiveness according to claim 1, wherein the new nano particles are added in a way of automatically opening a charging port at the top of the heat storage tank when the mass of the nano particles is detected to be reduced to 80.0%, and adding new nano particles with mass percentage of 20.0% of the total mass of the added nano particles into the heat storage tank, and continuously stirring.
4. The ternary chloride heat storage material with heat storage performance and corrosiveness according to claim 1, wherein the molten salt purity of single-component sodium chloride, potassium chloride and magnesium chloride is not lower than 99%, and the purity of nano particles is not lower than 98%.
5. The method for preparing ternary chloride heat storage material with heat storage performance and corrosiveness according to any one of claims 1 to 4, wherein the heat storage material is prepared by a melt blending method, and good dispersibility and compatibility are realized by mixing chloride and nano particles together at high temperature; the preparation method comprises the steps of respectively taking different powdery single-component chloride salts and nano particles with certain mass, placing the powdery single-component chloride salts and the nano particles in a drying box, drying for a period of time, respectively weighing the chlorine salts and the nano particles with an electronic balance according to mass ratio, physically mixing and stirring the three chloride salts and the nano particles to obtain composite chloride salt, then placing the composite chloride salt in a muffle furnace, heating to high temperature, continuously stirring and keeping constant temperature for a certain period of time after all the chlorine salts are melted, finally closing the muffle furnace, cooling and solidifying, taking out, grinding and drying to obtain the ternary chloride salt heat storage material with heat storage performance and corrosivity; The heating temperature and the constant temperature are 700-800 ℃, the continuous stirring time after melting is 1-2 hours, the constant temperature duration is 1-2 hours, and the cooling solidification temperature is 20-40 ℃.
6. The method according to claim 5, wherein the stirring method is purely mechanical stirring to uniformly mix the chloride salt and the nanoparticles, and the grinding method is to crush the solidified ternary chloride salt heat storage material into powder by using a pestle.
7. The method according to claim 5, wherein the drying treatment is to dry the single-component chloride salt or the composite chloride salt at a temperature of 100-120 ℃ under constant temperature ventilation conditions, at least 20 h.

Description

Ternary chloride heat storage material with heat storage performance and corrosiveness and preparation method thereof Technical Field The invention relates to the technical field of heat storage materials and material corrosion prevention, in particular to a ternary chloride salt heat storage material with heat storage performance and corrosiveness and a preparation method thereof. Background The fused salt is used as a potential heat storage and transfer material, has the characteristics of high heat transfer coefficient, high energy storage density, good heat stability, low production cost and the like, and has wide application prospect in the fields of high-temperature industrial waste heat recovery, solar heat utilization, nuclear energy and the like. Common molten salts include nitrate, carbonate and chloride salts. The nitrate has the characteristics of weak corrosiveness, low viscosity, low cost and the like. But its thermal stability is relatively poor and it is easily decomposed in a high temperature environment, thus limiting the application of nitrate in a high temperature environment. The carbonate has the characteristics of high melting point, large phase transition latent heat, low price and the like. But it has a high viscosity in liquid condition and is liable to clog the pipe, and thus is limited in application to the concentrating solar system. Compared with the fused salt, the chloride salt has the advantages of high decomposition temperature, wide working temperature range, rich material sources, low cost and the like. As solar thermal power generation systems evolve towards high parametrization, the demands on the molten salt operating temperature range are gradually rising, and mixed chloride salts are considered as the most promising heat storage materials in the next generation of concentrated solar power generation systems. However, the mixed chloride is used as a heat transfer and heat storage material at the present stage, and the problems of low heat conductivity, small specific heat capacity, strong corrosiveness and the like exist. The mixed chloride salt generally has the problems of small specific heat capacity and low heat conductivity, so that the problems of low heat storage density, low heat storage and release rate and the like of a heat storage system can be caused. And because of poor heat transfer, thermal stress problems can also be generated, and the safety of equipment is endangered. Therefore, improving the safety and working performance of the heat storage system depends on improving the thermophysical properties of the molten salt. The addition of metal and metal oxide nanoparticles to molten salts to alter the microstructure of the molten salts is considered to be an effective way of enhancing the heat storage/transfer properties of the molten salts. On the other hand, the strong corrosiveness of chloride salts to alloy materials is also a key issue limiting their further application in concentrated solar power systems. In molten chloride salts, there is a greater need for corrosion protection of the material because the alloy does not form an oxide film during exposure to inhibit corrosion due to the dissolution of the oxide in the molten salt. The method for retarding corrosion of molten chlorine salt to alloy material mainly includes adding corrosion inhibitor and alloy modification. For example, the addition of magnesium metal to molten chloride salts to neutralize corrosive components can greatly reduce the corrosion rate. And a coating barrier with thermodynamic stability and corrosion resistance is established on the surface of the alloy, so that the alloy is prevented from being directly contacted with molten chloride, and the corrosion rate can be greatly reduced, but the problems of complex operation, high cost and the like exist in the methods. Therefore, the molten salt heat storage material provided by the invention has the advantages of good heat storage performance, weak corrosiveness, simple preparation method and convenient operation, and has important practical significance. Disclosure of Invention The invention provides a ternary chloride salt heat storage material with heat storage performance and corrosiveness and a preparation method thereof, which solve the problems of poor heat conduction performance, low heat storage density and strong corrosiveness of the existing chloride molten salt and can be effectively applied to the technical field of energy storage in a solar thermal power generation system. In order to solve the problems, the invention adopts the following solutions: a ternary chloride salt heat storage material that combines heat storage properties and corrosiveness, comprising: The ternary mixed molten salt of sodium chloride, potassium chloride and magnesium chloride is added with nano particles for strengthening heat storage performance and weakening corrosion performance, and the ternary chloride salt heat storage material