阅读说明：本技术 一种陶瓷基高导热复合相变储热材料及制备方法 (Ceramic-based high-thermal-conductivity composite phase-change heat storage material and preparation method thereof ) 是由 杨波 王启扬 孙富华 刘杨 叶闻杰 杨肖 杜炜 杨冬梅 于 2020-04-13 设计创作，主要内容包括：本发明公开了一种陶瓷基高导热复合相变储热材料及制备方法,其原料组成质量百分比为：无机盐50%-70%,氮化铝20-50%,水5%-15%。首先按照配方比例称取无机盐、氮化铝搅拌均匀,加水混合后成型,制备复合相变储热材料前驱体；然后将前驱体密封包装置于鼓风干燥箱中低温反应制备生坯；最后将生坯加热烧结得到陶瓷基高导热复合相变储热材料。本发明通过原位反应的方法一步制备导热陶瓷基骨架,在封装共晶相变盐的同时大大增强了复合相变材料的导热性,热导率可达4W/m·K以上；由于采用了微米级的原料可显著降低生产成本,具备工业化生产的潜力。(The invention discloses a ceramic-based high-thermal-conductivity composite phase-change heat storage material and a preparation method thereof, wherein the ceramic-based high-thermal-conductivity composite phase-change heat storage material comprises the following raw materials in percentage by mass: 50-70% of inorganic salt, 20-50% of aluminum nitride and 5-15% of water. Firstly, weighing inorganic salt and aluminum nitride according to a formula proportion, uniformly stirring, adding water, mixing and forming to prepare a composite phase-change heat storage material precursor; then placing the precursor sealing package device in a blast drying oven for low-temperature reaction to prepare a green body; and finally, heating and sintering the green body to obtain the ceramic-based high-thermal-conductivity composite phase-change heat storage material. According to the invention, the heat-conducting ceramic matrix framework is prepared in one step by an in-situ reaction method, the heat conductivity of the composite phase change material is greatly enhanced while the eutectic phase change salt is packaged, and the heat conductivity can reach more than 4W/m.K; the micron-sized raw materials are adopted, so that the production cost can be obviously reduced, and the method has the potential of industrial production.)

1. The ceramic-based high-thermal-conductivity composite phase-change heat storage material is characterized by comprising the following components in percentage by mass:

50 to 70 percent of inorganic salt,

20 to 50 percent of aluminum nitride,

and the number of the first and second groups,

5 to 15 percent of water.

2. The ceramic-based high thermal conductivity composite phase change heat storage material of claim 1, wherein the inorganic salt is Na₂CO₃、Li₂CO₃、CaCO₃One or more of NaCl and KCl.

3. The ceramic-based high thermal conductivity composite phase change heat storage material of claim 1, wherein the aluminum nitride is technical grade with a particle size of 1-100 μm.

4. A preparation method of a ceramic-based high-thermal-conductivity composite phase-change heat storage material is characterized by comprising the following steps:

(1) weighing inorganic salt and aluminum nitride according to the proportion of the raw materials, uniformly stirring, adding water, mixing and forming to prepare a composite phase-change heat storage material precursor;

(2) sealing and packaging the prepared precursor, and placing the precursor in a forced air drying oven for low-temperature reaction to prepare a green body;

(3) and placing the prepared green body in a muffle furnace, and heating and sintering to obtain the ceramic-based high-thermal-conductivity composite phase-change heat storage material.

5. The preparation method of the ceramic-based high-thermal-conductivity composite phase-change heat storage material according to claim 4, wherein the raw materials comprise, by mass: 50-70% of inorganic salt, 20-50% of aluminum nitride and 5-15% of water.

6. The method for preparing the ceramic-based high-thermal-conductivity composite phase-change heat storage material according to claim 4, wherein the inorganic salt is Na₂CO₃、Li₂CO₃、CaCO₃One or more of NaCl and KCl.

7. The preparation method of the ceramic-based high-thermal-conductivity composite phase-change heat storage material according to claim 4, wherein the forming pressure is 20-40MPa, and the dwell time is 1-5 min.

8. The preparation method material of the ceramic-based high-thermal-conductivity composite phase-change heat storage material according to claim 4, wherein the set temperature of the air-blowing drying oven is 40-80 ℃, and the reaction time is 12-24 hours.

9. The preparation method of the ceramic-based high-thermal-conductivity composite phase-change heat storage material according to claim 4, wherein the heating and sintering process is as follows: heating to 105 ℃ at a certain heating rate, and keeping the temperature for 0.5-2 h; heating to 280-350 ℃ at a certain heating rate, and preserving heat for 1-3 h; finally, heating to 500-800 ℃ at a certain heating rate, and preserving heat for 2-4 h; cooling to room temperature along with the furnace.

10. The preparation method of the ceramic-based high-thermal-conductivity composite phase-change heat storage material according to claim 9, wherein the temperature rise rate is 5-20 ℃/min.

Technical Field

The invention relates to a ceramic-based high-thermal-conductivity composite phase-change heat storage material and a preparation method thereof, belonging to the technical field of phase-change material preparation.

Background

With the increasing shortage of energy supply and the increasing environmental protection pressure, phase-change materials are highly valued by people due to their unique characteristics and are applied to more and more fields, such as residential heating, steam production, waste heat recovery, and the like. The basic principle of the phase-change energy storage technology is to store energy through the isothermal phase-change process of materials and release the energy for use when needed, and the phase-change energy storage technology is an important means for solving the problem of mismatching of energy space and time.

In a phase-change material system, inorganic salts have a relatively proper melting point and relatively large phase-change latent heat, and attract extensive attention of various fields. However, the inorganic salt phase change material needs to solve two problems in the using process, namely material encapsulation is adopted, so that the corrosion to metal parts is reduced, and meanwhile, the modularized installation is convenient; secondly, strengthen heat conduction, improve the heat charge and discharge power, prevent local overtemperature. The common technical means at present is to compound the nanoscale adsorption material and graphite, but the production requirements are not satisfied enough, on one hand, the nanoscale adsorption material is expensive, and on the other hand, the graphite packaging process is high, so that potential safety hazards easily exist.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a ceramic-based high-thermal-conductivity composite phase-change heat storage material and a preparation method thereof.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

the invention provides a ceramic-based high-thermal-conductivity composite phase-change heat storage material, which comprises the following components in percentage by mass:

50 to 70 percent of inorganic salt,

20 to 50 percent of aluminum nitride,

and the number of the first and second groups,

5 to 15 percent of water.

Further, the inorganic salt is Na₂CO₃、Li₂CO₃、CaCO₃One or more of NaCl and KCl.

Furthermore, the aluminum nitride is industrial grade, and the granularity is 1-100 mu m.

The invention provides a preparation method of a ceramic-based high-thermal-conductivity composite phase-change heat storage material, which comprises the following steps:

(1) weighing inorganic salt and aluminum nitride according to the proportion of the raw materials, uniformly stirring, adding water, mixing and forming to prepare a composite phase-change heat storage material precursor;

(2) sealing and packaging the prepared precursor, and placing the precursor in a forced air drying oven for low-temperature reaction to prepare a green body;

(3) and placing the prepared green body in a muffle furnace, and heating and sintering to obtain the ceramic-based high-thermal-conductivity composite phase-change heat storage material.

Further, the raw materials comprise the following components in percentage by mass: 50-70% of inorganic salt, 20-50% of aluminum nitride and 5-15% of water.

Further, the inorganic salt is Na₂CO₃、Li₂CO₃、CaCO₃One or more of NaCl and KCl.

Further, the molding pressure is 20-40MPa, and the pressure maintaining time is 1-5 min.

Further, the temperature of the air-blast drying oven is set to be 40-80 ℃, and the reaction time is 12-24 hours.

Further, the heating sintering process comprises the following steps: heating to 105 ℃ at a certain heating rate, and keeping the temperature for 0.5-2 h; heating to 280-350 ℃ at a certain heating rate, and preserving heat for 1-3 h; finally, heating to 500-800 ℃ at a certain heating rate, and preserving heat for 2-4 h; cooling to room temperature along with the furnace.

Further, the heating rate is 5-20 ℃/min.

The invention has the beneficial effects that:

(1) according to the preparation method of the ceramic-based high-heat-conductivity composite phase-change heat storage material, the high-heat-conductivity composite phase-change heat storage material is prepared in one step by means of physical mixing and in-situ reaction, so that the heat conduction material and the adsorption material are more uniformly distributed, the phase-change material is prevented from cracking due to thermal stress generated by uneven temperature, and the practical phase-change heat storage material with high heat conductivity and good cycle stability is obtained. The phase-change temperature of the developed phase-change material is 400-800 ℃, and the phase-change material is suitable for the fields of steam production, photo-thermal storage, waste heat recovery and the like.

(2) The invention adopts aluminum nitride as a heat-conducting base material, has stable performance, low expansion rate, oxidation resistance and corrosion resistance, solves the problem of high-temperature oxidation of the graphite-based material, and has the heat conductivity of more than 4W/m.K.

(3) The invention does not need nano material as adsorbent, thus greatly reducing the cost of raw materials; the preparation process is simple, the material source is wide, the preparation method is suitable for large-scale industrial production, and the preparation method has wide application prospects in multiple fields.

Drawings

FIG. 1 is a diagram of a sample of example 1 of the present invention with no water added; FIG. 1(a) is a schematic representation of a finished product prepared in example 1 without the addition of water; FIG. 1(b) is a pictorial representation of a finished product prepared in example 1 with water;

FIG. 2 is an SEM photograph of a phase change material prepared according to example 1 of the present invention;

FIG. 3 is a DSC curve of the phase change material prepared in example 1 of the present invention and pure phase change salt.

Detailed Description

The invention is further described below. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The invention provides a ceramic-based high-thermal-conductivity composite phase-change heat storage material, which comprises the following components in percentage by mass:

50 to 70 percent of inorganic salt,

20 to 50 percent of aluminum nitride,

and the number of the first and second groups,

5 to 15 percent of water.

Further, the inorganic salt is Na₂CO₃、Li₂CO₃、CaCO₃One or more of NaCl and KCl.

Furthermore, the aluminum nitride is industrial grade, and the granularity is 1-100 mu m.

The invention also provides a preparation method of the ceramic-based high-thermal-conductivity composite phase-change heat storage material, which comprises the following steps:

(1) weighing inorganic salt and aluminum nitride according to a formula proportion, uniformly stirring, adding water, mixing and forming to prepare a composite phase-change heat storage material precursor;

(2) sealing and packaging the precursor prepared in the step (1), and placing the precursor in a forced air drying oven for low-temperature reaction to prepare a green body;

(3) and (3) placing the green body prepared in the step (2) in a muffle furnace, carrying out temperature programming, and heating and sintering to obtain the ceramic-based high-thermal-conductivity composite phase-change heat storage material.

Further, the formula comprises the following raw materials in percentage by mass: 50-70% of inorganic salt, 20-50% of aluminum nitride and 5-15% of water.

Further, the inorganic salt is Na₂CO₃、Li₂CO₃、CaCO₃One or more of NaCl and KCl.

Furthermore, the aluminum nitride is industrial grade, and the granularity is 1-100 mu m.

Further, the molding pressure is 20-40MPa, and the pressure maintaining time is 1-5 min.

Further, the temperature of the air-blast drying oven is set to be 40-80 ℃, and the reaction time is 12-24 hours.

Further, the heating sintering process comprises the following steps: heating to 105 ℃ at a certain heating rate, and keeping the temperature for 0.5-2 h; heating to 280-350 ℃ at a certain heating rate, and preserving heat for 1-3 h; finally, heating to 500-800 ℃ at a certain heating rate, and preserving heat for 2-4 h; cooling to room temperature along with the furnace.

Further, the heating rate is 5-20 ℃/min.