Carbonized melamine sponge phase change cold storage material for efficiently improving degree of supercooling

Abstract

The invention discloses a carbonized melamine sponge phase change cold storage material for efficiently improving the degree of supercooling, the carbonized melamine sponge phase change cold storage material is formed by compounding carbonized melamine sponge and a sodium chloride aqueous solution, and the carbonized melamine sponge is formed by sintering melamine sponge; the mass ratio of the carbonized melamine sponge to the sodium chloride aqueous solution is 1: (65-80). The carbonized melamine sponge for loading the phase change cold storage material is prepared by sintering. As the carbonized melamine sponge has a porous structure and surface characteristics, the carbonized melamine sponge can be used as an ideal carrier of a composite cold storage material, and after the carbonized melamine sponge is compounded with a sodium chloride aqueous solution, the supercooling degree of the sodium chloride aqueous solution can be remarkably reduced, meanwhile, high latent heat is kept, and the crystallization stability and the energy storage density are improved. The carbonized melamine sponge phase change cold storage material shows stable phase change performance in the range of-35 DEG C to 15 DEG C, and is suitable for various low-temperature application scenes.

Description

Technical Field

[0001] The present invention relates to a phase change material, and particularly to a carbonized melamine sponge phase change cold storage material for efficiently improving supercooling degree. Background Art

[0002] Phase change materials (such as aqueous sodium chloride solution) are commonly used in the fields of thermal energy storage and low-temperature cold storage. However, they have a relatively high supercooling degree, resulting in an unstable crystallization process in practical applications and affecting the thermal energy storage efficiency. In addition, traditional phase change materials have poor mechanical properties, making it difficult to meet the structural requirements in practical applications. Moreover, the wettability is insufficient, affecting their dispersibility and interfacial stability in composite materials, thereby limiting their application in complex environments. Summary of the Invention

[0003] In view of the above problems existing in traditional phase change materials, the present invention provides a carbonized melamine sponge phase change cold storage material for efficiently improving supercooling degree. By compounding carbonized melamine sponge with aqueous sodium chloride solution, the present invention significantly improves the supercooling degree of aqueous sodium chloride solution and increases its heat storage density.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] A carbonized melamine sponge phase change cold storage material for efficiently improving supercooling degree, which is composed of carbonized melamine sponge and aqueous sodium chloride solution, wherein:

[0006] The carbonized melamine sponge is sintered from melamine sponge, the sintering temperature is 200 - 400 °C, the sintering time is 30 - 150 min, the preferred sintering temperature is 400 °C, and the preferred sintering time is 150 min;

[0007] The mass concentration of the aqueous sodium chloride solution is 1 - 10%;

[0008] The mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:65 - 80.

[0009] Compared with the prior art, the present invention has the following advantages:

[0010] 1. The present invention prepares a carbonized melamine sponge for loading phase change cold storage material by sintering. Due to the porous structure and surface characteristics of the carbonized melamine sponge, it can be used as an ideal carrier for composite cold storage materials. After compounding it with aqueous sodium chloride solution, it can significantly reduce the supercooling degree of aqueous sodium chloride solution, while maintaining high latent heat, improving the crystallization stability and energy storage density.

[0011] 2. In the present invention, the mechanical properties and wettability of the melamine sponge are optimized after sintering and carbonization, so that it has better dispersibility and interfacial stability in the composite material.

[0012] 3. The phase change energy storage material of the carbonized melamine sponge of the present invention exhibits stable phase change performance in the range of -35°C to 15°C and is applicable to a variety of low-temperature application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a photograph of the sintered melamine sponge;

[0014] Figure 2 is a SEM image of the sintered carbonized melamine sponge;

[0015] Figure 3 is the thermal conductivity of the carbonized melamine sponge;

[0016] Figure 4 is the mechanical properties of the carbonized melamine sponge;

[0017] Figure 5 is the contact angle of the carbonized melamine sponge;

[0018] Figure 6 is a comparison chart of the energy storage density of the sodium chloride aqueous solution.

[0019] Figure 7 is a comparison chart of the supercooling degree. DETAILED DESCRIPTION OF THE INVENTION

[0020] The technical solution of the present invention will be further described below, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be covered by the protection scope of the present invention.

[0021] The present invention provides a carbonized melamine sponge phase change energy storage material for efficiently improving supercooling degree. The phase change energy storage material is composed of a carbonized melamine sponge and a sodium chloride aqueous solution, and the specific preparation steps are as follows:

[0022] Step 1. Preparation and characterization of the carbonized melamine sponge: Using a muffle furnace, with a heating rate of 5°C / min, the temperature is raised to 200°C, 300°C, and 400°C respectively, and the melamine sponge is sintered at each temperature for 30, 60, 90, 120, and 150 minutes respectively to obtain 15 carbonized melamine sponges. The photograph of the sintered melamine sponge is as Figure 1 shown. Observe its microstructure by scanning electron microscopy (SEM), test the thermal conductivity of the carbonized melamine sponge by HOT-disk, test the mechanical properties of the carbonized melamine sponge, including tensile strength and compressive yield point pressure, measure the contact angle of the carbonized melamine sponge, evaluate its surface wettability, and the measurement results are as Figures 2 to 5As shown. The melamine sponge with the best performance is selected through the above characterizations to load the cold storage material. After testing, the melamine sponge sintered at 400 °C for 150 min has good thermal conductivity and mechanical properties, and the contact angle is 0°, meeting the requirements of subsequent experiments. In the present invention, the melamine sponge is purchased from Shangpin Tiancheng on JD.com (nano sponge magic wipe), with a porosity of over 95% and good loading capacity.

[0023] Step 2: Study on the characteristics of the sodium chloride aqueous solution:

[0024] Prepare five sodium chloride aqueous solutions with mass concentrations of 1%, 3%, 5%, 7%, and 10% respectively, and use differential scanning calorimetry (DSC) to measure their phase change characteristics in the range of -35 °C to 15 °C respectively, obtaining the energy storage density and supercooling degree of the five sodium chloride aqueous solutions, as Figure 6 and Figure 7 shown.

[0025] Step 3: Preparation and performance testing of the composite phase change material:

[0026] Composite the carbonized melamine sponge and the sodium chloride aqueous solution according to the mass ratio in Table 1 (the maximum water absorption capacity of the carbonized melamine sponge after being put into the sodium chloride aqueous solution), and use DSC to test its phase change characteristics again, obtaining the energy storage density and supercooling degree of the five sodium chloride aqueous solutions, as Figure 6 and Figure 7 shown. From Figure 6 and Figure 7 it can be seen that the supercooling degree of the composite material is significantly reduced, while the energy storage density is significantly increased.

[0027] Table 1

[0028]

Claims

1. A phase change cold storage material of carbonized melamine sponge for efficiently improving supercooling degree, characterized in that The phase change cold storage material of the carbonized melamine sponge is composed of a carbonized melamine sponge and an aqueous sodium chloride solution, where: the mass concentration of the aqueous sodium chloride solution is 1-10%; the mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:65-80.

2. The phase change cold storage material of melamine sponge carbide for efficiently improving supercooling degree according to claim 1, characterized in that The carbonized melamine sponge is sintered from a melamine sponge, the sintering temperature is 200-400 °C, and the sintering time is 30-150 min.

3. The phase change cold storage material of melamine sponge carbide for efficiently improving supercooling degree according to claim 2, characterized in that The sintering temperature is preferably 400 °C, and the sintering time is preferably 150 min.

4. The phase change cold storage material of carbonized melamine sponge for efficiently improving supercooling degree according to claim 1, wherein The mass concentration of the aqueous sodium chloride solution is 1%, and the mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:76.

9.

5. The phase change energy storage material of melamine sponge carbonization for efficiently improving supercooling degree according to claim 1, characterized in that The mass concentration of the aqueous sodium chloride solution is 3%, and the mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:73.

9.

6. The phase change cold storage material of melamine sponge carbide for efficiently improving supercooling degree according to claim 1, characterized in that The mass concentration of the aqueous sodium chloride solution is 5%, and the mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:69.

2.

7. The phase change cold storage material of melamine sponge carbide for efficiently improving supercooling degree according to claim 1, characterized in that The mass concentration of the aqueous sodium chloride solution is 7%, and the mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:68.

6.

8. The phase change energy storage material of melamine sponge carbonization for efficiently improving supercooling degree according to claim 1, characterized in that The mass concentration of the aqueous sodium chloride solution is 10%, and the mass ratio of the carbonized melamine sponge to the aqueous sodium chloride solution is 1:65.3.

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