CN116478662A

CN116478662A - Inorganic phase change material and preparation method thereof

Info

Publication number: CN116478662A
Application number: CN202210051489.XA
Authority: CN
Inventors: 周军辉; 汤弢; 段昌明
Original assignee: Chunjun New Materials Shenzhen Co Ltd
Current assignee: Chunjun New Materials Shenzhen Co Ltd
Priority date: 2022-01-17
Filing date: 2022-01-17
Publication date: 2023-07-25

Abstract

The present disclosure provides an inorganic phase change material and a method of preparing the same, wherein the inorganic phase change material includes a phase change regenerator including a phase change matrix for storing and releasing cold and a nucleating agent for reducing supercooling degree of the phase change matrix, and a thermally conductive material for promoting heat transfer, the phase change regenerator includes 99 to 99.6% by mass of the phase change regenerator, the phase change matrix includes water and an inorganic salt, the inorganic salt includes at least one of magnesium chloride, calcium chloride, lithium chloride, and lithium bromide, the phase change regenerator includes 76 to 79% by mass of the water of the phase change matrix, 20 to 22% by mass of the inorganic salt, 1 to 2% by mass of the nucleating agent, the thermally conductive material includes at least one of graphite, copper oxide, and sodium chloride, and the thermally conductive material includes 0.4 to 1% by mass of the inorganic phase change material. According to the present disclosure, an inorganic phase change material having a strong heat conductive property and a method for preparing the same can be provided.

Description

Inorganic phase change material and preparation method thereof

Technical Field

The disclosure relates to the technical field of phase change materials, in particular to an inorganic phase change material and a preparation method thereof.

Background

With the rapid development of modern logistics and the increasing demand for cold chain transportation of pharmaceuticals, the cold chain logistics of pharmaceuticals is getting more and more attention. In the process of transporting medicines by a cold chain, the transportation temperature and the fluctuation range thereof need to be strictly controlled so as to ensure the storage effect of the transported medicines, vaccines, blood products and other articles. The phase-change energy storage technology has the advantages of high energy storage density, approximately constant temperature in the phase-change process, stable output energy and the like. The phase-change energy storage technology is coupled with the medicine cold chain transportation, so that the effects of constant temperature cold insulation, energy conservation and loss reduction can be realized.

The main working medium in the phase-change energy storage technology system is an inorganic phase-change material, which directly determines the quality of cold chain transportation. Therefore, the inorganic phase change material with proper phase change temperature interval, high latent heat value, low supercooling degree, no phase separation and good cycle stability is developed, and the method has great boosting effect on the development of industries such as medicine cold chain and the like. At present, the existing inorganic phase change material has the problem of low heat conductivity coefficient in practical application.

Disclosure of Invention

The present disclosure has been made in view of the above-mentioned conventional circumstances, and an object thereof is to provide an inorganic phase change material having a high heat conductive property and a method for producing the same.

To this end, the present disclosure provides, in one aspect, an inorganic phase change material including a phase change regenerator including a phase change matrix for storing and releasing cold and a nucleating agent for reducing supercooling degree of the phase change matrix, and a thermally conductive material for promoting heat transfer, wherein the phase change regenerator includes 99 to 99.6% by mass, the phase change matrix includes water and an inorganic salt including at least one of magnesium chloride, calcium chloride, lithium chloride, and lithium bromide, the phase change regenerator includes 76 to 79% by mass, 20 to 22% by mass, the nucleating agent includes 1 to 2% by mass, and the thermally conductive material includes at least one of graphite, copper oxide, and sodium chloride, and the thermally conductive material includes 0.4 to 1% by mass, in the inorganic phase change material.

In the present disclosure, the heat conductive property of the inorganic phase change material can be improved by adding a heat conductive material for promoting heat transfer, by enabling the inorganic phase change material to have a suitable phase change temperature and a higher latent heat of phase change by using a phase change matrix including an inorganic salt and water as a material for storing and releasing cold.

In addition, in the inorganic phase change material according to the present disclosure, optionally, the heat conductive material provides a heat conductive path for the collection and transmission of external heat. Thus, the heat conductive property of the inorganic phase change material can be advantageously improved.

In addition, in the inorganic phase change material according to the present disclosure, optionally, the graphite includes at least one of graphene and expanded graphite. Thus, the heat conductive property of the inorganic phase change material can be advantageously improved.

In addition, in the inorganic phase change material related to the present disclosure, optionally, a mass ratio of the thermally conductive material to the phase change cold storage agent is 1:99 to 1:200. thus, the phase transition temperature of the inorganic phase change material can be set within a predetermined range while improving the heat conductive property of the inorganic phase change material.

In addition, in the inorganic phase change material according to the present disclosure, optionally, the heat conductive material may be 0.5% to 0.6% by mass in the inorganic phase change material. Thus, the heat conductive property of the inorganic phase change material can be advantageously improved.

In addition, in the inorganic phase change material according to the present disclosure, the particle diameter of the heat conductive material is optionally 0.1 μm to 1 μm.

In addition, in the inorganic phase change material according to the present disclosure, optionally, the inorganic salt includes magnesium chloride and lithium chloride, and in the phase change cold storage agent, the mass fraction of magnesium chloride is 13% to 17%, and the mass fraction of lithium chloride is 3% to 7%. Thereby, the phase transition temperature of the inorganic phase change material can be made to lie within a predetermined range.

In addition, in the inorganic phase change material according to the present disclosure, optionally, the nucleating agent includes at least one of borax, strontium chloride, talc, titanium dioxide, silicon dioxide, calcium oxide, and magnesium oxide. In this case, the nucleating agent has good thermal stability and mechanical stability, and thus, it is possible to improve the cycle stability of the inorganic phase change material while reducing the supercooling degree of the inorganic phase change material.

In addition, in the inorganic phase change material according to the present disclosure, the particle diameter of the nucleating agent is optionally 1 μm to 10 μm. In this case, the dispersion of the nucleating agent in the inorganic phase change material can be facilitated, and thus the phase separation phenomenon generated during the phase change can be reduced.

Another aspect of the present disclosure provides a method for preparing an inorganic phase change material, comprising the steps of: preparing inorganic salt, water, a nucleating agent and a heat conducting material as preparation raw materials, adding the inorganic salt into the water, mixing to form a phase change matrix, adding the nucleating agent into the phase change matrix, mixing to form a phase change cold storage agent, adding the heat conducting material into the phase change cold storage agent, mixing to form the inorganic phase change material, wherein the inorganic salt comprises at least one of magnesium chloride, calcium chloride, lithium chloride and lithium bromide, the mass fraction of the water in the phase change cold storage agent is 76-79%, the mass fraction of the inorganic salt is 20-22%, the mass fraction of the nucleating agent is 1-2%, the mass fraction of the heat conducting material comprises at least one of graphite, copper oxide and sodium chloride, the mass fraction of the phase change cold storage agent in the inorganic phase change material is 99-99.5%, and the mass fraction of the heat conducting material in the inorganic phase change material is 0.5-1%.

According to the present disclosure, an inorganic phase change material having a strong heat conductive property and a method for preparing the same can be provided.

Drawings

The present disclosure will now be explained in further detail by way of example only with reference to the accompanying drawings, in which

Fig. 1 is a flowchart illustrating a method of preparing an inorganic phase change material according to an example of the present disclosure.

Fig. 2A is a step-cooling graph illustrating an inorganic phase change material of example 1 of the present disclosure.

Fig. 2B is a DSC graph showing an inorganic phase change material of embodiment 1 of the present disclosure.

Fig. 2C is a DSC graph showing the inorganic phase change material of example 1 of the present disclosure after 100 cycles.

Fig. 3A is a step-cooling graph illustrating an inorganic phase change material of example 2 of the present disclosure.

Fig. 3B is a DSC graph showing an inorganic phase change material of embodiment 2 of the present disclosure.

Fig. 3C is a DSC graph showing the inorganic phase change material of example 2 of the present disclosure after 100 cycles.

Fig. 4A is a step-cooling graph illustrating an inorganic phase change material of example 3 of the present disclosure.

Fig. 4B is a DSC graph showing an inorganic phase change material of example 3 of the present disclosure.

Fig. 4C is a DSC graph showing the inorganic phase change material of example 3 of the present disclosure after 100 cycles.

Fig. 5A is a step-cooling graph illustrating an inorganic phase change material of example 4 of the present disclosure.

Fig. 5B is a DSC graph showing an inorganic phase change material of example 4 of the present disclosure.

Fig. 5C is a DSC graph showing the inorganic phase change material of example 4 of the present disclosure after 100 cycles.

Fig. 6A is a step-cooling graph illustrating an inorganic phase change material of example 5 of the present disclosure.

Fig. 6B is a DSC graph showing an inorganic phase change material of example 5 of the present disclosure.

Fig. 6C is a DSC graph showing the inorganic phase change material of example 5 of the present disclosure after 100 cycles.

Fig. 7A is a step-cooling graph illustrating an inorganic phase change material of example 6 of the present disclosure.

Fig. 7B is a DSC graph showing an inorganic phase change material of example 6 of the present disclosure.

Fig. 7C is a DSC graph showing the inorganic phase change material of example 6 of the present disclosure after 100 cycles.

Fig. 8A is a step-cooling graph illustrating an inorganic phase change material of comparative example 1 of the present disclosure.

Fig. 8B is a DSC graph showing the inorganic phase change material of comparative example 1 of the present disclosure.

Fig. 8C is a DSC graph showing the inorganic phase change material of comparative example 1 of the present disclosure after 100 cycles.

Fig. 9A is a step-cooling graph illustrating an inorganic phase change material of comparative example 2 of the present disclosure.

Fig. 9B is a DSC graph showing the inorganic phase change material of comparative example 2 of the present disclosure.

Fig. 9C is a DSC graph showing the inorganic phase change material of comparative example 2 of the present disclosure after 100 cycles.

Fig. 10A is a step-cooling graph illustrating an inorganic phase change material of comparative example 3 of the present disclosure.

Fig. 10B is a DSC graph showing the inorganic phase change material of comparative example 3 of the present disclosure.

Fig. 10C is a DSC graph showing the inorganic phase change material of comparative example 3 of the present disclosure after 100 cycles.

Fig. 11A is a step-cooling graph illustrating an inorganic phase change material of comparative example 4 of the present disclosure.

Fig. 11B is a DSC graph showing the inorganic phase change material of comparative example 4 of the present disclosure.

Fig. 11C is a DSC graph showing the inorganic phase change material of comparative example 4 of the present disclosure after 100 cycles.

Fig. 12A is a step-cooling graph illustrating an inorganic phase change material of comparative example 5 of the present disclosure.

Fig. 12B is a DSC graph showing the inorganic phase change material of comparative example 5 of the present disclosure.

Fig. 12C is a DSC graph showing the inorganic phase change material of comparative example 5 of the present disclosure after 100 cycles.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same members are denoted by the same reference numerals, and overlapping description thereof is omitted. In addition, the drawings are schematic, and the ratio of the sizes of the components to each other, the shapes of the components, and the like may be different from actual ones.

In this embodiment, the inorganic phase change material (hereinafter may be simply referred to as phase change gel) according to the present disclosure may be used as a coolant for storage or transportation of medicines, reagents, vaccines, blood products, biological samples and related products, etc. For example, as a coolant for maintaining the temperature at-38 ℃ to-42 ℃.

In some examples, the inorganic phase change materials contemplated by the present disclosure may be used in refrigerated transportation, daily refrigerated use, and the like. For example, when the inorganic phase change material is used as a coolant for refrigerated transportation, it can be used for a refrigerated compartment, a refrigerated ice bag, a mobile refrigeration house, etc.; for example, when the inorganic phase change material is used as a coolant for daily refrigeration, it can be used for a refrigerator, an in-vehicle incubator, or the like.

In some examples, when using the inorganic phase change material of the present disclosure, the inorganic phase change material may be contained within a sealed package to prepare a cooling bag for use. The cooling bag manufactured in this way can be placed in an incubator to insulate objects to be insulated (such as food, medicines, etc.) in the incubator.

Specifically, in some examples, the shape of the cooling bag containing the inorganic phase change material has various shapes, for example, the shape of the cooling bag can be adaptively set according to the shape of the object to be insulated in the insulation can, so that the cooling bag can fully contact the object to be insulated, and the cooling bag can fully exchange heat with the object to be insulated, thereby better improving the insulation effect.

In some examples, the inorganic phase change material to which the present disclosure relates may also be a shape stable inorganic phase change material (Form-stable phase change materials, FSPCM). For example, the inorganic phase change material may be a shaped inorganic phase change material. Thus, leakage during phase transition can be reduced.

In some examples, the phase transition temperature of the inorganic phase change material may be-38 ℃ to-42 ℃. Thus, the inorganic phase change material can be applied to a scene where the temperature needs to be maintained at-38 ℃ to-42 ℃. For example, the phase transition temperature of the inorganic phase change material may be-38 ℃, -38.2 ℃, -38.5 ℃, -39 ℃, -39.5 ℃, -40 ℃, -40.5 ℃, -40.8 ℃, -41 ℃, -41.5 ℃, -41.7 ℃, -41.9 ℃ or-42 ℃.

In some examples, the pH of the inorganic phase change material may be neutral or slightly alkaline. In some examples, the pH of the inorganic phase change material may be 7 to 8.5. In this case, the growth of the crystal nuclei can be facilitated, and in addition, the corrosion of the metal container by the brine can be reduced. For example, the pH of the inorganic phase change material may be 7, 7.5, 8, or 8.5.

In this embodiment, the inorganic phase change material may include a heat conductive material for promoting heat transfer. In this case, a heat conduction channel can be provided for the collection and transmission of external heat by adding the heat conduction material, thereby improving the heat conduction performance of the inorganic phase change material.

In some examples, when an inorganic phase change material with high thermal conductivity is used for cold chain transport of materials, the efficiency of heat transfer from the materials to the inorganic phase change material can be increased, thereby enabling rapid cooling. In some examples, additionally, improving the thermal conductivity of the inorganic phase change material by adding a thermally conductive material can also facilitate increasing the rate of cold charging of the inorganic phase change material during cold charging, thereby reducing the pre-cool storage time.

In some examples, the thermally conductive material may include at least one of graphite, copper oxide, and sodium chloride. Wherein the graphite may include at least one of graphene and expanded graphite. In some examples, the graphite may also include at least one of flake graphite, pyrolytic graphite, and carbon nanotubes.

In some examples, the thermally conductive material has a particle size of 0.1 μm to 1 μm. Wherein particle size may refer to the outer diameter of the thermal material. For example, the particle size of the thermally conductive material is 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm. In this case, it can be advantageous to improve the heat conductive property of the inorganic phase change material.

In some examples, the mass percent of thermally conductive material in the inorganic phase change material may be 0.4% to 1%. For example, the mass percent of the thermally conductive material may be 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%. Thus, the heat conductive property of the inorganic phase change material can be advantageously improved.

In some examples, preferably, the mass percentage in the thermally conductive material inorganic phase change material may be 0.5% to 0.6%. Thus, the heat conductive property of the inorganic phase change material can be advantageously improved.

In some examples, the inorganic phase change material may include a phase change coolant. The phase change cold storage agent may be used as a host material of the inorganic phase change material and for storing and releasing cold energy so that the phase change temperature and the phase change latent heat of the inorganic phase change material are within a predetermined range.

In some examples, the mass percent of phase change coolant in the inorganic phase change material may be 99% to 99.6%. For example, the mass percent of the phase change regenerator may be 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, or 99.6%. Thereby, the phase transition temperature and the latent heat of phase transition of the inorganic phase transition material can be brought within a predetermined range.

In some examples, the phase change coolant may include a phase change matrix for storing and releasing cold. The phase change matrix absorbs or releases a large amount of latent heat in the phase change process to realize the function of phase change energy storage or release.

In some examples, the mass fraction of phase change matrix in the phase change coolant may be 98% to 99%. For example, in a phase change coolant, the mass fraction of the phase change matrix may be 98%, 98.3%, 98.5%, 98.8%, or 99%. Thereby, the phase transition temperature of the inorganic phase change material can be made to lie within a predetermined range.

In some examples, the phase change matrix may include water and an inorganic salt. Water may be the primary energy storage material in the primary energy storage agent. Inorganic salts can be used as temperature control materials in the phase change matrix. That is, the phase transition temperature of the inorganic phase change material may be adjusted by the inorganic salt.

In some examples, the inorganic salt may include at least one of magnesium chloride, calcium chloride, lithium chloride, and lithium bromide. In this case, the inorganic salt is capable of forming a low temperature eutectic salt and is compounded with water to bring the phase transition temperature of the inorganic phase change material within a predetermined range.

In some examples, the mass percent of magnesium chloride in the inorganic salt may be 13% to 17%. For example, the mass percent of magnesium chloride in the inorganic salt may be 13%, 14%, 15%, 16%, or 17%. Thereby, the phase transition temperature of the inorganic phase change material can be made to lie within a predetermined range.

In some examples, the mass percent of lithium chloride in the inorganic salt may be 3% to 7%. For example, the mass percent of lithium chloride in the inorganic salt may be 3%, 4%, 5%, 6%, or 7%. Thereby, the phase transition temperature of the inorganic phase change material can be made to lie within a predetermined range.

In some examples, the mass fraction of inorganic salt in the phase change coolant may be 20% to 22%. For example, the mass fraction of inorganic salt in the phase change coolant may be 20%, 20.5%, 21%, 21.5%, or 22%. Thereby, the phase transition temperature of the inorganic phase change material can be made to lie within a predetermined range.

In some examples, the mass fraction of water in the phase change coolant may be 76% to 79%. For example, in a phase change coolant, the mass fraction of water may be 76%, 77%, 77.5%, 78%, or 79%. Thereby, the phase transition temperature of the inorganic phase change material can be made to lie within a predetermined range.

In some examples, the phase change matrix may be a mixture of water and inorganic salts. In some examples, in the phase change matrix, the mass ratio of inorganic salt to water may be 20:79 to 22:76. In this case, the phase transition temperature of the inorganic phase change material can be adjusted to be within a predetermined range. For example, in a phase change matrix, the mass ratio of inorganic salt to water may be 20: 79. 20.5:78.5, 21: 78. 21.5:77.5, 22:77 or 22:76.

In some examples, the phase change coolant may also include a nucleating agent. The nucleating agent may be used to reduce supercooling of the inorganic phase change material. Specifically, the nucleating agent can play a role of a crystal nucleus in the inorganic phase-change material, and the supercooling degree of the inorganic phase-change material is reduced by inducing the inorganic phase-change material to perform crystallization, so that the phase-change temperature of the inorganic phase-change material is in a preset range.

In some examples, the nucleating agent may be at least one of borax, strontium chloride, talc, titanium dioxide, silicon dioxide, calcium oxide, magnesium oxide. In this case, the nucleating agent has good thermal stability and mechanical stability, and thus, it is possible to improve the cycle stability of the inorganic phase change material while reducing the supercooling degree of the inorganic phase change material.

In some examples, the nucleating agent may be spherical, cylindrical, or irregular. In some examples, the particle size of the nucleating agent may be 1 μm to 10 μm. The particle size of the nucleating agent may refer to the diameter of the nucleating agent particles. In this case, the dispersion of the nucleating agent in the inorganic phase change material can be facilitated, and thus the phase separation phenomenon generated during the phase change can be reduced. For example, the particle size of the nucleating agent may be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm or 10 μm.

In some examples, the mass fraction of nucleating agent in the phase change regenerator may be 1% to 2%. For example, in a phase change regenerator, the mass fraction of the nucleating agent may be 1%, 1.3%, 1.5%, 1.7%, 1.9%, or 2%. In this case, it can be helpful to reduce the supercooling degree of the inorganic phase change material.

In some examples, the inorganic phase change material may further include a pH adjuster. The pH adjustor can be used to adjust the pH of the inorganic phase-change material, for example, the pH of the inorganic phase-change material can be maintained in the range of 7 to 8.5 by the pH adjustor. In this case, it is possible to promote the formation of fine crystal nuclei of the inorganic phase change material during the phase change and stabilize the nucleation by adjusting the pH of the inorganic phase change material to a predetermined range.

In some examples, the inorganic phase change material may be composed of a phase change coolant with a thermally conductive material. In this case, the phase change temperature and the phase change latent heat of the inorganic phase change material can be adjusted by the phase change cold storage agent, and the thermal conductivity of the inorganic phase change material can be enhanced by the thermal conductive material, so that the inorganic phase change material with high thermal conductivity is obtained.

In some examples, the mass ratio of thermally conductive material to phase change coolant may be 1:99 to 1:200. for example, the mass ratio of thermally conductive material to phase change coolant may be 1: 99. 1: 100. 1: 120. 1: 140. 1: 150. 1: 160. 1: 170. 1: 180. 1: 190. or 1:200. thus, the phase transition temperature of the inorganic phase change material can be set within a predetermined range while improving the heat conductive property of the inorganic phase change material.

In this embodiment, the combination of the components and the proportions in the system of the inorganic phase change material can make the phase change temperature of the inorganic phase change material between-38 ℃ and-42 ℃ and can have high heat conduction property. In the inorganic phase change material related to the disclosure, high phase change latent heat and proper phase change temperature can be obtained through the phase change cold storage agent, and the phase change cold storage agent is mixed with the heat conduction material, so that the heat conduction performance of the inorganic phase change material can be improved.

Fig. 1 is a flowchart illustrating a method of preparing an inorganic phase change material according to an example of the present disclosure. Hereinafter, a method of preparing an inorganic phase change material according to an example of the present embodiment will be described in detail with reference to fig. 1.

In this embodiment, as shown in fig. 1, the method for preparing an inorganic phase change material may include: preparing inorganic salt, water, nucleating agent and heat conducting material as preparation raw materials (step S100); adding inorganic salt into water, mixing to form a phase change matrix (step S200); adding a nucleating agent into the phase change matrix, and mixing to form a phase change cold storage agent (step S300); and adding a heat conducting material into the phase change cold storage agent, and mixing to form an inorganic phase change material (step S400).

In some examples, in the preparation process of the inorganic phase change material (i.e., step S100, step S200, step S300, and step S400), specific descriptions (e.g., components and proportions) of the inorganic salt, water, the nucleating agent, and the heat conductive material may be referred to the descriptions of the inorganic phase change material above, and will not be repeated herein.

In some examples, in step S200, water and inorganic salt may be mixed by stirring. Thereby facilitating the mixing of water and inorganic salts. For example, in step S200, the solution (i.e., the phase change matrix) may be clarified by stirring at a speed of 400 to 700 revolutions per minute for 1-2 hours.

In some examples, in step S200, stirring may be performed under the condition of 25 ℃ to 80 ℃. If the inorganic salt includes either magnesium chloride or calcium chloride, the mixing and stirring operation of magnesium chloride and calcium chloride in water may be performed at normal temperature, since a large amount of heat is released when they meet water. Further, the inorganic salt may be added to the water in small amounts in batches. This can facilitate the mixing of water and inorganic salts.

In some examples, in step S300, the nucleating agent and the phase change matrix may be mixed by stirring. Thereby facilitating the mixing of the nucleating agent and the phase change matrix. For example, in step S300, the phase change coolant may be stirred at a rotation speed of 400 to 700 rpm for 1 to 2 hours. In some examples, in step S300, stirring may be performed under the condition of 25 ℃ to 80 ℃.

In some examples, in step S400, the thermally conductive material and the phase change cold storage agent may be mixed by stirring. Thereby facilitating the mixing of the thermally conductive material and the phase change thermal storage agent. For example, in step S400, the inorganic phase change material may be stirred at a rotation speed of 400 to 700 rpm for 1 to 2 hours. In some examples, in step S400, stirring may be performed under the condition of 25 ℃ to 80 ℃.

In some examples, in step S400, the pH of the inorganic phase change material may be measured, and if the pH value thereof is not within a predetermined range, a pH adjuster may be added to adjust. For a specific description of the pH adjustor, reference may be made to the description of the inorganic phase change material above, and no further description is given here.

In this embodiment, a specific description of the inorganic phase change material prepared by the preparation method may be referred to the description of the inorganic phase change material above. According to the present disclosure, an inorganic phase change material having a strong heat conductive property and a method for preparing the same can be provided.

For further explanation of the present disclosure, the inorganic phase change materials provided by the present disclosure are described in detail below with reference to examples, and the advantageous effects achieved by the present disclosure are fully explained with reference to comparative examples.

Examples (example)

In each of embodiments 1 to 6, first, the inorganic phase change material of each embodiment is prepared. Specifically, each of the examples prepares a raw material according to the raw material ratio of the inorganic phase change materials of examples 1 to 6 in table 1, then adds the prepared inorganic salt to deionized water, and stirs it under normal temperature conditions until a clear solution (i.e., phase change matrix) is obtained; then adding the prepared nucleating agent into the phase-change matrix, and continuously stirring for 1.5h at room temperature (25 ℃); finally, the prepared heat conductive material was added and stirred at room temperature (25 ℃) for 1.5 hours, thereby obtaining the inorganic phase change materials of examples 1 to 6.

Comparative example

Comparative examples 1 to 5 were prepared in the same manner as in the above examples, except that the preparation raw materials were replaced with the substances shown in table 1, to obtain inorganic phase change materials of comparative examples 1 to 5.

Performance tests were performed on the inorganic phase change materials of each example (examples 1 to 6) and each comparative example (comparative examples 1 to 5) prepared according to table 1. The method comprises the following steps:

(1) Measuring the phase transition temperature of the inorganic phase transition material by a step-cooling curve method;

(2) Measuring the phase transition temperature and the cycling stability of the inorganic phase change material by using a Differential Scanning Calorimetry (DSC);

(3) The heat conduction performance of the inorganic phase change material is measured by a scattering method laser heat conduction instrument under the condition of room temperature (25 ℃).

The results of performance testing of the inorganic phase change materials prepared in each of the examples and comparative examples are shown in table 2, and fig. 2A to 12C.

Table 1 raw material ratios for preparing inorganic phase change materials

TABLE 2 Performance test results of inorganic phase change materials

As can be seen from table 2 and fig. 2A to 12C, the inorganic phase change materials obtained in each of examples (examples 1 to 6) had a phase transition temperature of between-38 ℃ and-42 ℃, a latent heat of phase transition of higher than 130.38J/g, good cycle stability, and a thermal conductivity of higher than 0.9W/(m·k) (i.e., good thermal conductivity), and specifically, the inorganic phase change materials of examples 1 to 6 had a change rate of the phase transition temperature of not more than 1.92% after 100 cycles, and a decrease rate of the latent heat of phase transition of not more than 2.8%. In contrast, the inorganic phase change materials obtained in the comparative examples (comparative examples 1 to 5) cannot simultaneously achieve the performance effects of the inorganic phase change materials obtained in the respective examples described above.

In summary, the phase transition temperature of the inorganic phase transition material obtained in each embodiment is between-38 ℃ and-42 ℃, and the inorganic phase transition material has good cycle stability and good heat conduction performance.

While the disclosure has been described in detail in connection with the drawings and examples, it is to be understood that the foregoing description is not intended to limit the disclosure in any way. Modifications and variations of the present disclosure may be made as desired by those skilled in the art without departing from the true spirit and scope of the disclosure, and such modifications and variations fall within the scope of the disclosure.

Claims

1. An inorganic phase change material, characterized in that: comprising a phase-change cold storage agent, and a heat-conducting material for promoting heat transfer, the phase-change cold storage agent comprising a phase-change matrix for storing and releasing cold, and a nucleating agent for reducing the supercooling degree of the phase-change matrix, wherein in the inorganic phase-change material, the phase-change cold storage agent has a mass percentage of 99% to 99.6%, the phase-change matrix comprises water and an inorganic salt, the inorganic salt comprises at least one of magnesium chloride, calcium chloride, lithium chloride, and lithium bromide, in the phase-change cold storage agent, the mass percentage of water of the phase-change matrix is 76% to 79%, the mass percentage of the inorganic salt is 20% to 22%, the mass percentage of the nucleating agent is 1% to 2%, the heat-conducting material comprises at least one of graphite, copper oxide, and sodium chloride, and in the inorganic phase-change material, the mass percentage of the heat-conducting material is 0.4% to 1%.

2. The inorganic phase change material of claim 1, wherein:

the heat conducting material provides a heat conducting channel for the collection and transmission of external heat.

3. The inorganic phase change material of claim 1, wherein:

the graphite includes at least one of graphene and expanded graphite.

4. The inorganic phase change material of claim 1, wherein:

the mass ratio of the heat conduction material to the phase change cold storage agent is 1:99 to 1:200.

5. the inorganic phase change material of claim 1, wherein:

the mass percentage of the heat conduction material in the inorganic phase change material is 0.5-0.6%.

6. The inorganic phase change material of claim 1, wherein:

the particle size of the heat conductive material is 0.1 μm to 1 μm.

7. The inorganic phase change material of claim 1, wherein:

the inorganic salt includes magnesium chloride and lithium chloride, and in the phase change cold storage agent, the mass fraction of magnesium chloride is 13% to 17%, and the mass fraction of lithium chloride is 3% to 7%.

8. The inorganic phase change material of claim 1, wherein:

the nucleating agent comprises at least one of borax, strontium chloride, talcum powder, titanium dioxide, silicon dioxide, calcium oxide and magnesium oxide.

9. The inorganic phase change material of claim 1, wherein:

the particle size of the nucleating agent is 1 μm to 10 μm.

10. The preparation method of the inorganic phase change material is characterized by comprising the following steps: preparing inorganic salt, water, a nucleating agent and a heat conducting material as preparation raw materials, adding the inorganic salt into the water, mixing to form a phase change matrix, adding the nucleating agent into the phase change matrix, mixing to form a phase change cold storage agent, adding the heat conducting material into the phase change cold storage agent, mixing to form the inorganic phase change material, wherein the inorganic salt comprises at least one of magnesium chloride, calcium chloride, lithium chloride and lithium bromide, the mass fraction of the water in the phase change cold storage agent is 76-79%, the mass fraction of the inorganic salt is 20-22%, the mass fraction of the nucleating agent is 1-2%, the mass fraction of the heat conducting material comprises at least one of graphite, copper oxide and sodium chloride, the mass fraction of the phase change cold storage agent in the inorganic phase change material is 99-99.5%, and the mass fraction of the heat conducting material in the inorganic phase change material is 0.5-1%.