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CN-122010567-A - High-heat-conductivity shaped composite phase change material and preparation method and application thereof

CN122010567ACN 122010567 ACN122010567 ACN 122010567ACN-122010567-A

Abstract

The invention belongs to the technical field of heat storage systems, and particularly relates to a high-heat-conductivity shaping composite phase change material, and a preparation method and application thereof. The invention mixes graphite powder, carbon nitride and ammonium bicarbonate, and prepares the graphite foam with a three-dimensional porous structure by adopting a compression drying method. A series of graphite foam matrixes with different adsorption effects are prepared by regulating and controlling the addition amount of ammonium bicarbonate, and a porous matrix with high heat conduction and good encapsulation effect is successfully prepared. The method is favorable for the phase change material to show excellent heat conductivity and leakage resistance, and has great application potential in the fields of heat dissipation and heat storage. Meanwhile, the preparation method of the shaped composite phase change material with high heat conduction effectively improves the heat conduction performance of the composite phase change material, and shows excellent heat storage/release rate and low leakage performance, so that the preparation method has a good application prospect in the aspect of a solar heating system.

Inventors

  • TAN XIN
  • GAO LEI
  • QI HUI
  • HE ZHANQING
  • YANG QIAO
  • LEI XUAN

Assignees

  • 内蒙古科技大学

Dates

Publication Date
20260512
Application Date
20260203

Claims (10)

  1. 1. A method for preparing graphite foam, comprising the steps of: Taking melamine and urea as reactants, and calcining to obtain carbon nitride; Adding ethanol into phenolic resin, and uniformly mixing to obtain phenolic resin-ethanol solution; Adding the carbon nitride, graphite powder and ammonium bicarbonate into the phenolic resin-ethanol solution, stirring, carrying out ultrasonic treatment, drying, grinding, sieving, compacting, and carrying out sectional heating treatment to obtain the graphite foam.
  2. 2. The preparation method according to claim 1, wherein the mass ratio of melamine to urea is 1:9; and/or the temperature of the calcination treatment is 550 ℃, the temperature rising rate is 5 ℃ per minute, and the heat preservation time is 3 hours; And/or the mass ratio of the phenolic resin to the ethanol is 1:105; and/or the rotation speed of the uniform mixing is 500rpm, the temperature is 40 ℃ and the time is 30min.
  3. 3. The method of claim 1, wherein the mass ratio of graphite powder to carbon nitride is 9:1; and/or the mass ratio of the sum of the masses of the graphite powder and the carbon nitride to the ammonium bicarbonate is 1:3-5; and/or the mass ratio of the sum of the masses of the carbon nitride, the graphite powder and the ammonium bicarbonate to the phenolic resin-ethanol solution is 12-19:15-16.
  4. 4. The method of claim 1, wherein the stirring is carried out at a speed of 800rpm for a period of 1 hour; and/or, the temperature of the ultrasonic wave is 40 ℃ and the time is 40min; And/or drying in a forced air drying oven for 6 hours to remove ethanol; and/or, the number of the grinding and sieving meshes is 80 mesh; And/or the pressure of the compression molding is 50MPa, and the pressure maintaining time is 5min; and/or the sectional heating treatment is to heat up to 120 ℃ after heat preservation treatment for 2 hours at 80 ℃.
  5. 5. A graphite foam produced by the production process according to any one of claims 1 to 4.
  6. 6. Use of the graphite foam of claim 5 as a phase change material carrier in a solar thermal storage system.
  7. 7. The high-heat-conductivity shaped composite phase change material is characterized by comprising the following components in percentage by mass: The graphite foam of claim 5 22-32% and the balance 1-octadecanol.
  8. 8. A method of preparing the high thermal conductivity shaped composite phase change material of claim 7, comprising the steps of: Immersing graphite foam into melted 1-octadecanol, and cooling after vacuum adsorption to obtain the high-heat-conductivity shaped composite phase-change material.
  9. 9. The method of claim 8, wherein the vacuum adsorption is performed at a temperature of 80 ℃ for a time of 1h.
  10. 10. Use of the shaped composite phase change material of claim 7 in a solar thermal storage system.

Description

High-heat-conductivity shaped composite phase change material and preparation method and application thereof Technical Field The invention belongs to the technical field of heat storage systems, and particularly relates to a high-heat-conductivity shaping composite phase change material, and a preparation method and application thereof. Background Heat storage technology has received attention in recent years as an important means for solving the imbalance of energy supply and demand and improving the utilization efficiency of renewable energy. Among the numerous ways of storing heat, latent heat storage presents unique advantages due to its high energy density and nearly constant temperature heat storage and release characteristics, the core of which is that the phase change material absorbs or releases a large amount of latent heat during the state transition. The organic phase change material becomes a research hot spot due to the characteristics of good chemical stability, high phase change enthalpy value, small supercooling degree and the like, wherein 1-octadecanol is used as a typical fatty alcohol phase change material, has high phase change enthalpy of about 240-260J/g and phase change temperature (55-60 ℃) close to a human body comfort zone, and has wide application prospect in the fields of building energy conservation, electronic equipment heat management, solar heat storage and the like. However, although single phase change materials (such as 1-octadecanol) have excellent heat storage performance, the inherent low thermal conductivity and liquid leakage problems severely limit practical applications. The current research is mainly carried out by introducing and the heat conducting filler is used for improving the heat conducting property. However, in the traditional method, the filler is randomly distributed in the matrix, and along with the recycling of the phase change material, the filler is easy to generate sedimentation phenomenon, so that the heat conduction network is damaged, and the performance of the composite phase change material is reduced. Therefore, how to solve the problems of poor thermal performance and easy liquid phase leakage during melting of the composite phase change material becomes a difficult problem to overcome by those skilled in the art. Disclosure of Invention The invention aims to provide a high-heat-conductivity shaped composite phase-change material, and a preparation method and application thereof, so as to solve the problems in the prior art. In order to achieve the above object, the present invention provides the following solutions: According to one of the technical schemes, the invention provides a preparation method of graphite foam, which comprises the following steps: Taking melamine and urea as reactants, and calcining to obtain carbon nitride; Adding ethanol into phenolic resin, and uniformly mixing to obtain phenolic resin-ethanol solution; Adding the carbon nitride, graphite powder and ammonium bicarbonate into the phenolic resin-ethanol solution, stirring, carrying out ultrasonic treatment, drying, grinding, sieving, compacting, and carrying out sectional heating treatment to obtain the graphite foam. Further, the mass ratio of melamine to urea is 1:9. Further, the temperature of the calcination treatment is 550 ℃, the temperature rising rate is 5 ℃ per minute, and the heat preservation time is 3 hours. Further, the mass ratio of the phenolic resin to the ethanol is 1:105. Further, the rotation speed of the uniform mixing is 500rpm, the temperature is 40 ℃ and the time is 30min. Further, the mass ratio of the graphite powder to the carbon nitride is 9:1. Further, the mass ratio of the sum of the masses of the graphite powder and the carbon nitride to the ammonium bicarbonate is 1:3-5. Further, the mass ratio of the sum of the carbon nitride, the graphite powder and the ammonium bicarbonate to the phenolic resin-ethanol solution is 12-19:15-16. Further, the stirring speed was 800rpm for 1 hour. Further, the temperature of the ultrasonic wave is 40 ℃ and the time is 40min. Further, the drying is to dry in a forced air drying oven for 6 hours to remove ethanol. Further, the mesh number of the grinding and sieving is 80 mesh. Further, the pressure of the compression molding is 50MPa, and the dwell time is 5min. Further, the sectional heating treatment is to heat up to 120 ℃ for 2 hours after heat preservation at 80 ℃ for 2 hours. The second technical scheme of the invention is to provide the graphite foam prepared by the preparation method. In the prior art, the conventional graphite foam (such as comparative example 3) is generally prepared by mixing graphite powder and ammonium bicarbonate, pressing and forming, and heat treatment, and compared with the conventional graphite foam, the graphite foam prepared by the method disclosed by the invention has the advantages that carbon nitride prepared from melamine and urea is added, so that the leakage re