Multi-metal step-change phase thermal insulation material

Abstract

The application discloses a multi-metal step-change phase change heat insulation material. When used, a high-thermal-conductivity and high-melting-point phase change metal material layer is arranged close to a heat source, a large amount of concentrated heat is diffused to a phase change metal material layer with a low melting point by using the high-thermal-conductivity capacity, a certain temperature gradient is formed between different metal material layers in the melting process, and heat is stored in different temperature zones by phase change, and the heat insulation effect of a heat insulation layer is combined, so that the effects of heat storage, temperature control and heat insulation can be considered in a narrow space, and excellent performance is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal insulation, in particular to a multi-metal step phase change thermal insulation material. BACKGROUND

[0002] Some high-power devices will generate a large amount of heat when working, such as electron guns, engines, laser devices, strong electromagnetic devices, etc. When they work normally, most of the energy is converted into internal energy, resulting in a large amount of heat concentrated locally, the temperature rises continuously, and seriously affects the working performance of the device or even causes the device to burn out. For these high-power devices, various heat dissipation technologies are needed to cool them, achieve temperature control, and ensure stable operation of the device.

[0003] Recently, high-power devices have developed towards lightweight, miniaturization and high power, generating more heat and more concentrated heat, with a heat flux density of 100W / cm2~1000W / cm2 and a temperature of several hundred or even thousands of degrees Celsius in the heating area. This puts higher requirements on compact, lightweight and efficient high-temperature thermal control and thermal insulation technology.

[0004] The commonly used temperature control technology at present is forced convection cooling, which drives the cooling liquid to quickly flush the high-temperature surface to achieve the purpose of cooling and temperature control. However, the normal operation of this type of temperature control technology requires a series of circulating pipelines and control systems, and the overall cooling system is heavy in mass, large in volume and high in energy consumption, which cannot meet the demand.

[0005] In response to this, a phase change material and a thermal insulation layer are combined to form a thermal insulation and temperature control technology, but the material configuration is relatively simple, and the thermal insulation performance cannot meet the demand, which needs to be improved. SUMMARY

[0006] To solve at least one of the above technical defects, the present application provides the following technical solutions:

[0007] The present application discloses a multi-metal step phase change thermal insulation material, which comprises a phase change layer one and a thermal insulation layer arranged in layers. The phase change layer one is a metal step phase change type, and comprises a plurality of phase change metal material layers. In the phase change layer one, the phase change metal material layer with low melting point covers the phase change metal material layer with high thermal conductivity and high melting point. The phase change metal material layer with high thermal conductivity and high melting point is separated from the composite thermal insulation layer above the phase change layer one by a phase change metal material layer with lower melting point.

[0008] In use, the high-thermal-conductivity and high-melting-point phase-change metal material layer is arranged adjacent to the heat source, the heat source transmits heat to the high-thermal-conductivity and high-melting-point phase-change metal material layer, the high-thermal-conductivity and high-melting-point phase-change metal material layer diffuses the concentrated heat to the low-melting-point phase-change metal material layer by virtue of the high-thermal-conductivity, and the different metal material layers have a certain temperature gradient in the melting process, and the heat is stored in different temperature zones. In combination with the heat insulation of the heat insulation layer, the heat storage, temperature control, and heat insulation effects can be achieved in a narrow space, and the performance is excellent.

[0009] For the phase-change metal material layer in the phase-change layer one, the number of layers can be selected according to requirements, such as two, three, four, etc.

[0010] For the heat insulation layer, it can be selected from the market according to requirements, such as a single heat insulation material or a multi-layer heat insulation layer, or other layer structures with heat insulation effects.

[0011] Further, the phase-change layer one includes a first phase-change metal material layer, a second phase-change metal material layer, and a third phase-change metal material layer, the third phase-change metal material layer covers the second phase-change metal material layer, and the second phase-change metal material layer covers the first phase-change metal material layer. In this example, the phase-change layer one is composed of three phase-change metal material layers, and the thickness of the phase-change layer one is small under the premise of maintaining excellent heat insulation effect, and can be better arranged in a narrow space.

[0012] Further, the first phase-change metal material layer is formed by one or more of copper, silver, gold, aluminum, or alloys thereof; the third phase-change metal material layer is formed by one or more of gallium, indium, tin, bismuth, or alloys thereof; and the second phase-change metal material layer is formed by a material with a melting point between those of the first phase-change metal material layer and the third phase-change metal material layer. The first phase-change metal material belongs to the high-thermal-conductivity and high-melting-point type, and its main purpose is to diffuse the concentrated heat to other areas. The second and third phase-change metal material layers absorb heat by phase change in stages according to the different melting points. The material of the second phase-change metal material layer can be selected from the material types of the first phase-change metal material layer and the third phase-change metal material layer, and the melting point is the only requirement.

[0013] Further, the wall layer one is provided between the phase-change layer one or between the phase-change layer one and the heat insulation layer, and the wall layer one plays a role of isolation and protection. For example, the wall layer one is in abutment with the heat source, and the wall layer one is preferably formed by a high-melting-point and high-strength material, such as high-temperature titanium alloy, high-temperature steel, red copper, etc.

[0014] In use, the temperature of the wall layer one can be controlled under the heat absorption and heat storage of the phase-change layer one, such as keeping the temperature of the wall layer one below the melting point to maintain the stability of the structure.

[0015] Further, the phase change layer two is formed by a high-thermal-conductivity and high-melting-point phase change metal, and is arranged on the side of the phase change layer one away from the heat insulation layer, so as to replace the wall layer one with the phase change layer two, increase the heat conduction capacity, and quickly spread and transfer the heat to the phase change layer one.

[0016] Further, the heat insulation layer comprises a wall layer two, a vacuum chamber, a partition plate and a phase change material layer, the vacuum chamber, the partition plate and the phase change material layer are arranged in layers between the wall layer two, and the phase change material layer is separated from the phase change layer one below by the vacuum chamber.

[0017] In the scheme, the heat insulation layer is newly designed, the phase change material layer is separated from the phase change layer one by the vacuum chamber, the heat transferred from the phase change layer one is transferred to the vacuum chamber, and then the vacuum chamber is transferred to the phase change material layer, so that the phase change material layer absorbs and stores the heat, and the heat is further reduced to the wall layer two above the phase change material layer, and the heat insulation effect is excellent.

[0018] Further, the phase change material layer is a hydrated salt type or an organic type phase change material.

[0019] Further, the phase change material layer is formed by one or more of sodium carbonate decahydrate, sodium acetate trihydrate or paraffin.

[0020] Further, the composite phase change material layer is formed by a high phase change latent heat material, and the phase change layer one or the heat insulation layer is arranged in a cavity formed in the composite phase change material layer, in the scheme, the composite phase change material layer is added, the composite phase change material layer can assist the phase change layer one to absorb heat, the composite phase change material is a high phase change latent heat type, has a high equivalent thermal conductivity, can diffuse a large amount of concentrated heat to the whole area, so that the temperature of the composite phase change material layer is almost constant and remains in a low temperature range for a long time, in addition, the volume of the composite phase change material layer can be changed according to the structure size, and is suitable for temperature control of high-power equipment with high heat concentration and long-time work in narrow space.

[0021] Further, the composite phase change material layer comprises a high-thermal-conductivity skeleton and a filling material, the filling material is one or more of water and salt type, paraffin or sugar alcohol type material, and the skeleton is formed by porous graphite, carbon foam, foamed copper or foamed aluminum.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1. The multi-metal step phase change thermal insulation material of the present application is suitable for high temperature thermal control field, and the phase change metal material layer with high thermal conductivity and high melting point transfers the concentrated heat to other phase change metal material layer with low melting point, a certain temperature gradient is formed between different metal layers, heat is stored at different temperature zones, and the effects of heat storage, temperature control and thermal insulation in narrow space can be realized by the step structure with light mass, no energy consumption and small volume under the auxiliary thermal insulation of the thermal insulation layer, and temperature control of high power equipment is realized.

[0024] 2. The structure composition of the thermal insulation layer is designed, and the vacuum chamber cooperated with the phase change material layer can further improve the thermal insulation effect.

[0025] 3. The composite phase change material layer and the phase change layer one cooperate with the thermal insulation layer, can cooperate with the phase change layer one to absorb, diffuse and store heat, and further improve the effects of thermal insulation and temperature control. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0027] Figure 1 is a structure schematic diagram of the thermal insulation material in embodiment 1;

[0028] Figure 2 is a structure schematic diagram of the thermal insulation material in embodiment 2;

[0029] Figure 3 is a structure schematic diagram of the thermal insulation material in embodiment 3;

[0030] Among them, the reference signs are:

[0031] 1, heat source; 2, wall layer one; 3, phase change layer one; 4, thermal insulation layer; 5, wall layer two; 6, vacuum chamber; 7, partition; 8, phase change material layer; 9, composite phase change material layer; 10, phase change layer two; 301, first phase change metal material layer; 302, second phase change metal material layer; 303, third phase change metal material layer. DETAILED DESCRIPTION

[0032] The present application will be further described below in combination with the drawings and specific embodiments.

[0033] Embodiment 1:

[0034] As Figure 1As shown, the multi-metal step-change phase change thermal insulation material includes a thermal insulation layer 4, a phase change layer one 3 stacked from top to bottom, the phase change layer one is of a metal step-change phase change type, and the phase change layer one is composed of multiple phase change metal material layers, such as two, three, four, more, etc.

[0035] In this example, the phase change layer one is composed of three metal phase change material layers, which are a first phase change metal material layer 301, a second phase change metal material layer 302, and a third phase change metal material layer 303. The first phase change metal material layer is formed by a material with high thermal conductivity and high melting point, such as one or more of copper, silver, gold, aluminum, or their alloys. In this example, the first phase change metal material layer is formed by silver.

[0036] The melting point of the second phase change metal material layer 302 is lower than that of the first phase change metal material layer 301. Therefore, the second phase change metal material layer 302 covers the top and side surfaces of the first phase change material layer 301, similar to a sleeve structure. The second phase change metal material layer 302 is formed by one or more of aluminum, bismuth, tin, indium, or their alloys. In this example, the second phase change metal material layer is formed by aluminum.

[0037] The melting point of the third phase change metal material layer 303 is lower than that of the second phase change metal material layer 302. Therefore, the third phase change metal material layer 303 covers the top and side surfaces of the first phase change material layer 301. The third phase change metal material layer is formed by one or more of gallium, indium, tin, bismuth, or their alloys. In this example, the third phase change metal material layer is formed by tin.

[0038] To isolate and protect the phase change layer one, a wall layer one 2 is added in this example, such as Figure 1 As shown, the phase change layer one is placed in the cavity formed between the wall layer one 2 and the thermal insulation layer. The bottom surfaces of the first, second, and third phase change metal material layers in the phase change layer one abut the inner wall surface of the wall layer one 2. In use, the outer wall surface of the wall layer one 2 abuts the heat source 1. Therefore, the wall layer one 2 is preferably formed by a material with high melting point and high strength, such as high-temperature titanium alloy, high-temperature steel, red copper, etc. In this example, the wall layer one is formed by red copper. Of course, in other embodiments, the phase change layer one can also be placed in the cavity between two wall layers.

[0039] For the thermal insulation layer, a layer structure with thermal insulation performance can be selected from the market according to needs. Preferably, as shown in Figure 1 The thermal insulation layer includes a wall layer two 5, a vacuum chamber 6, a partition 7, and a phase change material layer 8. The vacuum chamber 6, the partition 7, and the phase change material layer 8 are stacked and placed between the wall layer two 5. The phase change material layer 8 is separated from the phase change layer one below by the vacuum chamber 6.

[0040] For the second wall layer, if the second wall layer in contact with the first phase change layer is formed with a high melting point titanium alloy, the second wall layer at the outermost layer can be formed with a material with a lower melting point, such as aluminum alloy. The inner and outer wall layers can be formed with different materials according to requirements.

[0041] For a vacuum chamber, which is a chamber where some air or gas is removed, a vacuum chamber 6 is formed by evacuating the chamber between the second wall layer and the partition. This restricts both convection and contact heat transfer, thus providing good insulation. A phase change material layer 8 is placed in the chamber between the partition 7 and the upper second wall layer 5. The material of this phase change material layer is selected based on the temperature control of the adjacent second wall layer. Preferably, it is a water- or salt-type phase change material or an organic phase change material, which has advantages such as high heat storage capacity and low thermal conductivity. Specific examples include sodium carbonate decahydrate, sodium acetate trihydrate, and paraffin wax. This material can store the thermal radiation energy of the vacuum chamber and reduce the temperature rise of the second wall layer. In this example, the phase change material layer is illustrated using paraffin wax molding.

[0042] Furthermore, to further improve the thermal insulation performance, a composite phase change material layer 9 is added in this example. This composite phase change material layer 9 is a high latent heat of phase change material. For example... Figure 1 As shown, a composite phase change material layer 9 is placed in the cavity between wall layer 2 and the upper wall layer 5. Phase change layer 1 is located in the cavity formed by the composite phase change material layer 9. Figure 1 In the state shown, the two sides of phase change layer 1 are in contact with the corresponding composite phase change material layer 9.

[0043] For composite phase change material layers, such as those including a high thermal conductivity skeleton and filler materials, the filler materials are one or more of water and salt type, paraffin or sugar alcohol type materials, and the skeleton is formed by carbon foam, porous graphite, copper foam or aluminum foam. In this example, the composite phase change material layer is formed by mixing paraffin and copper foam, and the ratio between the two can be selected according to the requirements.

[0044] like Figure 1 As shown, during use, the heat source transfers heat to one of the wall layers. The first metal phase change material absorbs the concentrated heat of the first wall layer and diffuses it to the second metal phase change material layer and the third metal phase change material layer. The third metal phase change material layer melts first and uses sensible heat and latent heat to store the heat transferred by the second metal phase change material layer, so that the temperature of the second metal phase change material layer remains almost constant and in the medium-low temperature range.

[0045] When the third metal phase change material layer is basically completely melted, the second metal phase change material layer begins to melt and stores the heat transferred by the first phase change metal material layer during the phase change process, so that the temperature of the first metal phase change material layer remains almost constant and the temperature of the first metal phase change material layer is still maintained in the medium temperature range.

[0046] When the temperature of the wall layer one in contact with the heat source is too high, the first metal phase change material layer can also melt and store the heat of the wall layer one in the phase change process, so that the temperature of the wall layer one remains almost constant and is lower than the melting point of the material of the wall layer one, which can avoid the burning of the equipment.

[0047] The heat transferred from the phase change layer one to the heat insulation layer is reduced through vacuum chamber insulation, heat absorption and storage of the phase change material layer, and the composite phase change material layer can also absorb and store the heat transferred from the phase change layer one and the wall layer one, further reducing the heat transferred to the heat insulation layer, and cooperating to reduce the temperature rise of the outer wall layer two, thereby achieving the desired heat insulation effect.

[0048] Example 2:

[0049] As shown in Figure 2 , the difference between the heat insulation material of this example and example 1 is that the phase change layer one 3 and the heat insulation layer are both in the cavity formed in the composite phase change material layer 9, and the lower wall layer one 3 is in contact with the bottom surface of the composite phase change material layer 9, which helps to achieve short-distance wall temperature control and heat insulation.

[0050] As shown in Figure 2 , the phase change material layer is preferably wrapped with a vacuum chamber, and the phase change material layer is separated from the composite phase change material layer with a vacuum chamber.

[0051] The heat source continuously acts on the wall layer one, and the temperature of each metal phase change material layer rises, especially the temperature near the heat source rises significantly. When the local temperature of the surface of the third metal phase change material layer rises to a certain value, the lower surface of the composite phase change material layer begins to change phase and absorbs a large amount of heat. At the same time, due to the insertion of the high thermal conductivity skeleton, the equivalent thermal conductivity of the composite phase change material layer is high, which effectively diffuses a large amount of concentrated heat to the entire area, so that the temperature of the composite phase change material layer remains almost constant and is in the medium-low temperature or even normal temperature range for a long time. Since the volume of the composite phase change material layer can be changed according to the structure size, it is suitable for temperature control of high-power equipment working for a long time in narrow spaces with high heat concentration.

[0052] Example 3:

[0053] As shown in Figure 3 , compared with the heat insulation material in example 1, the phase change layer two 10 is added in this example to replace the wall layer one, and the phase change layer two 10 is formed by high thermal conductivity and high melting point phase change metal, such as the composition of the phase change layer two 10 and the first metal phase change material layer 301 in the phase change layer one. In this example, silver is also used to form the phase change layer two as an example.

[0054] The phase change layer two 10 is located on the side of the phase change layer one away from the heat insulation layer, and the composite phase change material layer 9 and the phase change layer one are located in the cavity between the phase change layer two 10 and the wall layer two 5.

[0055] Increase the heat conduction capacity, quickly spread the heat to the phase change layer, and the composite phase change material layer.

[0056] The above is only the preferred embodiment of the present application, the protection scope of the present application is not limited to the above-mentioned examples, all technical solutions belonging to the idea of the present application are within the protection scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, some improvements and decorations, these improvements and decorations should be considered as the protection scope of the present application.

Claims

1. A multi-metal step phase change thermal insulation material, comprising a phase change layer one (3) and a thermal insulation layer (4) arranged in a stack, characterized in that, The phase change layer one (3) is a metal step phase change type, the phase change layer one (3) includes multiple phase change metal material layers, the phase change metal material layer with low melting point is coated in the phase change layer one (3) The phase change metal material layer with high thermal conductivity and high melting point is separated by the phase change metal material layer with lower melting point between the phase change layer one (3) and the heat insulation layer (4) above; The phase change layer one (3) includes a first phase change metal material layer (301), a second phase change metal material layer (302), and a third phase change metal material layer (303), the third phase change metal material layer (303) is coated with the second phase change metal material layer (302), and the second phase change metal material layer (302) is coated with the first phase change metal material layer (301); The first phase change metal material layer (301) is one or more of copper, silver, gold, aluminum or its alloy; The third phase change metal material layer (303) is one or more of gallium, indium, tin, bismuth or its alloy; The melting point of the material forming the second phase change metal material layer (302) is between the melting points of the materials forming the first and third phase change metal material layers; It also includes a composite phase change material layer (9), which is a high phase change latent heat material type, and the phase change layer one (3) or the phase change layer one (3) and the heat insulation layer (4) are both in the chamber separated in the composite phase change material layer (9); The heat insulation layer (4) includes a wall surface layer two (5), a vacuum chamber (6), a partition (7), and a phase change material layer (8), the vacuum chamber (6), the partition (7), and the phase change material layer (8) are arranged in layers between the wall surface layer two (5), and the phase change material layer (8) is separated from the phase change layer one (3) below by the vacuum chamber (6); The composite phase change material layer (9) includes a high thermal conductivity type framework and a filling material, the filling material is one or more of water and salt type, paraffin or sugar alcohol type material, and the framework is formed by porous graphite, carbon foam, foam copper or foam aluminum.

2. The multi-metal step phase change thermal barrier of claim 1, wherein: It also includes a wall surface layer one (2), and the phase change layer one (3) is arranged between the wall surface layer one (2) or between the wall surface layer one (2) and the heat insulation layer (4).

3. The multi-metal step phase change thermal barrier of claim 1, wherein: It also includes a phase change layer two (10), which is a high thermal conductivity and high melting point phase change metal type, and the composition of the first phase change metal material layer (301) in the phase change layer one is consistent with the phase change layer two (10), and the phase change layer two (10) is on the side of the phase change layer one (3) away from the heat insulation layer (4).

4. The multi-metal step phase change thermal barrier of claim 1, wherein: The phase change material layer (8) is a hydrated salt type or an organic type phase change material type.

5. The multi-metal step phase change thermal barrier of claim 4, wherein: The phase change material layer (8) is one or more of sodium carbonate decahydrate, sodium acetate trihydrate or paraffin.

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