CN-121975498-A - Three-dimensional center oriented porous structure photo-thermal energy storage composite phase change material and preparation method thereof

Abstract

The invention relates to the technical field of solar energy storage, in particular to a photo-thermal energy storage composite phase change material with a three-dimensional center directional porous structure and a preparation method thereof. The hydroxyethyl cellulose, the carboxylated carbon nano tube and the sodium tetraborate decahydrate are assembled into a three-dimensional center directional porous structure framework by a brass die, and the composite phase change material with high-efficiency photo-thermal conversion performance is obtained by vacuum impregnation and absorption of lauric acid. And the cross-linking of the carboxylated carbon nano tube and the hydroxyethyl cellulose provides the photo-thermal conversion capability for the porous structure skeleton, and the cross-linking of the sodium tetraborate decahydrate and the hydroxyethyl cellulose enhances the stability of the porous structure. The three-dimensional center directional porous structure can prevent the phase change material from leaking on one hand, and can rapidly transfer heat generated by photo-thermal conversion into the material on the other hand, so that integrated high-efficiency photo-thermal conversion storage is carried out. The material is assembled into the three-dimensional center orientation structure composite phase change material, so that efficient photo-thermal conversion can be performed.

Inventors

• XU HAILONG
• BING NAICI
• YU WEI
• LI XIAOMENG
• LIU WANXIANG
• WANG SHIYUAN

Assignees

• 上海第二工业大学

Dates

Publication Date

20260505

Application Date

20260128

Claims (6)

1. 1. The photo-thermal energy storage composite phase change material with the three-dimensional center oriented porous structure is characterized by comprising, by weight, 1-3 parts of hydroxyethyl cellulose, 2-6 parts of sodium tetraborate decahydrate, 0.1-0.3 part of carboxylated carbon nanotubes and 90-100 parts of deionized water.
2. 2. The preparation method of the photo-thermal energy storage composite phase change material with the three-dimensional center orientation porous structure as claimed in claim 1, which is characterized by comprising the following steps: (1) Dispersing hydroxyethyl cellulose into deionized water, placing the deionized water on a magnetic stirrer at 40 ℃, and stirring the mixture at 400r/min for 30min to obtain cellulose dispersion liquid; (2) Adding carboxylated carbon nanotubes into the cellulose dispersion liquid in the step (1), and carrying out ultrasonic treatment for 30 minutes at 40 ℃ and 40Hz to obtain black dispersion liquid; (3) Adding sodium tetraborate decahydrate into the black dispersion liquid in the step (2), placing the black dispersion liquid on a magnetic stirrer at 40 ℃ and stirring the mixture for 6 hours at 400r/min to obtain a prepolymer dispersion liquid; (4) Adding the prepolymer dispersion liquid in the step (3) into a brass mold, putting into liquid nitrogen for freezing, and then performing freeze drying to obtain a three-dimensional center directional porous structure material; (5) Immersing the three-dimensional center oriented porous structure material in the step (4) into molten lauric acid, and adsorbing for 12 hours in a 60 ℃ vacuum oven to obtain the three-dimensional center oriented porous structure photo-thermal energy storage composite phase change material.
3. 3. The preparation method of the photo-thermal energy storage composite phase-change material with the three-dimensional center-oriented porous structure, which is disclosed in claim 2, is characterized in that the mass ratio of hydroxyethyl cellulose to deionized water in the step (1) is 1-3:100.
4. 4. The method for preparing the photo-thermal energy storage composite phase change material with the three-dimensional center orientation porous structure, which is disclosed in claim 2, is characterized in that the mass ratio of the carboxylated carbon nanotubes to the deionized water in the step (2) is 0.1-0.3:100.
5. 5. The preparation method of the photo-thermal energy storage composite phase-change material with the three-dimensional center-oriented porous structure, which is disclosed in claim 2, is characterized in that the mass ratio of sodium tetraborate decahydrate to deionized water in the step (3) is 2-6:100.
6. 6. The method for preparing the photo-thermal energy storage composite phase change material with the three-dimensional center orientation porous structure, which is disclosed in claim 2, is characterized in that the brass die in the step (4) is obtained by processing a hemispherical pit structure on the top surface of brass with a cylindrical structure.

Description

Three-dimensional center oriented porous structure photo-thermal energy storage composite phase change material and preparation method thereof Technical Field The invention relates to the technical field of solar energy storage, in particular to a photo-thermal energy storage composite phase change material with a three-dimensional center directional porous structure and a preparation method thereof. Background With the growing global energy demand, the continuous consumption of fossil energy has raised increasingly serious energy shortage and environmental pollution problems. In order to alleviate this dilemma, the use of renewable solar energy for the photo-thermal conversion and storage of it as thermal energy has become an effective solution. The photo-thermal energy storage technology is classified into sensible heat energy storage, latent heat energy storage and thermochemical energy storage according to a heat storage mode. Latent heat storage utilizes materials to absorb or release latent heat during phase change to store energy. The organic phase change material has the advantages of high energy storage density, capability of storing and releasing heat in a smaller temperature difference range, almost no supercooling degree and the like. However, the solar energy storage device has the defects of no photo-thermal conversion effect, low heat conductivity, easy liquid phase leakage and the like, and seriously hinders the application in the field of solar energy storage. The phase change material is packaged by using the porous structure material, so that leakage can be prevented on one hand, and the photo-thermal property of the phase change material can be improved on the other hand. Therefore, how to prepare an effective porous structure packaging material is a technical problem that needs to be solved by the present technicians. Disclosure of Invention Aiming at the defects of the prior art, the invention provides the photo-thermal energy storage composite phase-change material with the three-dimensional center directional porous structure and the preparation method thereof, solves the problem of leakage of the phase-change material, improves the photo-thermal conversion capability of the phase-change material, and can be expanded to the assembly of three-dimensional center directional structures of other materials. The preparation method of the photo-thermal energy storage composite phase-change material with the three-dimensional center orientation porous structure comprises the following steps: (1) Hydroxyethyl cellulose was dispersed in deionized water and placed on a magnetic stirrer at 40 ℃ and stirred at 400r/min for 30min to obtain a cellulose dispersion. (2) Adding carboxylated carbon nanotubes into the cellulose dispersion liquid in the step (1), and carrying out ultrasonic treatment for 30 minutes at 40 ℃ and 40Hz to obtain black dispersion liquid. (3) Sodium tetraborate decahydrate was added to the black dispersion of step (2), and the mixture was placed on a magnetic stirrer at 40℃and stirred at 400r/min for 6 hours to obtain a prepolymer dispersion. (4) And (3) adding the prepolymer dispersion liquid in the step (3) into a brass mold, putting into liquid nitrogen for freezing, and then performing freeze drying to obtain the three-dimensional center directional porous structure material. (5) Immersing the three-dimensional center oriented porous structure material in the step (4) into molten lauric acid, and adsorbing for 12 hours in a 60 ℃ vacuum oven to obtain the three-dimensional center oriented porous structure photo-thermal energy storage composite phase change material. Preferably, the mass ratio of the hydroxyethyl cellulose to the deionized water in the step (1) is 1-3:100. Preferably, the mass ratio of the carboxylated carbon nanotubes to the deionized water in the step (2) is 0.1-0.3:100. Preferably, the mass ratio of the sodium tetraborate decahydrate to the deionized water in the step (3) is 2-6:100. Preferably, the brass mold in step (4) is as shown in fig. 1. The working principle is that hydroxyethyl cellulose is crosslinked with sodium tetraborate decahydrate to enhance mechanical stability, and then the hydroxyethyl cellulose is crosslinked with a carbon nano tube to add photo-thermal conversion capability. The skeleton structure is assembled into a three-dimensional center oriented structure through oriented freezing and absorbs lauric acid, so that heat generated by photo-thermal conversion of the carbon nano tube can be quickly conducted into the material, and the lauric acid is subjected to solid-liquid phase to store energy. The invention provides a photo-thermal energy storage composite phase change material with a three-dimensional center directional porous structure and a preparation method thereof. The beneficial effects are as follows: 1. According to the invention, the porous framework is assembled by crosslinking hydroxyethyl cellulose and sodium tetrabor