Customized roof shape solar material, its preparation method and application

Abstract

The application discloses a customized roof-shaped solar material and a preparation method and application thereof. The solar material is a solar phase change energy storage material, and comprises a first composite layer and a second composite layer. The preparation raw materials of the first composite layer comprise 8-12 parts of sunflower acid or polyethylene glycol, 0.5-1.5 parts of carbon black and 0.008-0.015 parts of a surfactant according to weight fractions. The preparation raw materials of the second composite layer comprise 40-80 parts of sunflower acid or polyethylene glycol and 0.5-2 parts of expanded perlite according to weight fractions. The molecular weight of the polyethylene glycol is 1500-2000. The solar phase change energy storage material has excellent low-temperature heat storage capacity, can release or absorb a large amount of latent heat in a phase change process, has a high energy density characteristic, and the phase change latent energy reaches 179 kJ kg-1 ‑1 Moreover, the solar material preparation method is simple and suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of solar energy materials technology, and in particular to a customized roof-shaped solar energy material, its preparation method, and its application. Background Technology

[0002] With the rapid advancement of science and technology, human demand for energy is increasing daily. Traditional energy sources (such as oil and coal) are prone to environmental pollution and are non-renewable, necessitating the search for clean, green, and renewable new energy sources to replace them. Solar energy is one such energy source. Common solar energy products include solar thermal phase change energy storage tiles, solar photovoltaic tiles, and solar collectors. Among these, solar thermal phase change energy storage tiles and solar photovoltaic tiles can replace existing roof tiles, absorbing sunlight and converting it into heat or electricity. They can also be assembled and customized according to customer needs, showing promising application prospects. However, the conversion efficiency of solar photovoltaic tiles is limited and affected by temperature; high temperatures reduce conversion efficiency. Solar thermal phase change energy storage tiles, on the other hand, can store thermal energy through phase change energy storage materials. When needed, the stored thermal energy can be used for heating, hot water supply, or driving steam power generation, making their applications more widespread than those of solar photovoltaic tiles.

[0003] In related technologies, solar thermal phase change energy storage tiles utilize the phase change process of phase change materials (PCMs) to store and release energy. High-performance PCMs should possess the following characteristics: (1) suitable phase change temperature; (2) high latent heat storage capacity; (3) stable chemical and thermal properties; (4) non-toxic, non-corrosive, and environmentally friendly; (5) low cost and easy availability; and (6) high thermal conversion rate. However, in related technologies, the PCMs often fail to meet these requirements, leading to unstable solar energy supply. Furthermore, in areas with limited sunlight, conventional solar phase change energy storage materials are difficult to effectively store heat due to low light intensity, severely restricting the application of solar energy.

[0004] Therefore, there is still a need to find a solar energy material with low-temperature heat storage capacity and excellent chemical and thermal stability. Summary of the Invention

[0005] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a solar phase change energy storage material, which has excellent low-temperature heat storage capacity, can release or absorb a large amount of latent heat during the phase change process, has high energy density characteristics, and has a relatively smaller volume and lower preparation cost compared with inorganic phase change materials, making it suitable for industrial production.

[0006] This invention also proposes a method for preparing solar phase change energy storage materials.

[0007] This invention also proposes a solar thermal phase change energy storage tile.

[0008] This invention also proposes the application of a solar phase change energy storage material or its preparation method in the preparation of energy storage materials.

[0009] In a first aspect, the present invention provides a solar phase change energy storage material, comprising:

[0010] The first composite layer, wherein the raw materials for preparing the first composite layer, by weight, include: 8-12 parts of succinic acid or polyethylene glycol, 0.5-1.5 parts of carbon black and 0.008-0.015 parts of surfactant;

[0011] The second composite layer, the raw materials for preparing the second composite layer, by weight, include: 40 to 80 parts of succinic acid or polyethylene glycol, and 0.5 to 2 parts of expanded perlite;

[0012] The molecular weight of the polyethylene glycol is 1500-2000.

[0013] The solar phase change energy storage material according to embodiments of the present invention has at least the following beneficial effects:

[0014] (1) For solar phase change energy storage materials, capric acid or PEG was selected as the main phase change energy storage raw materials. They have good thermal stability and can maintain good thermal performance during the phase change process, which helps to improve the efficiency of energy storage and release. In addition, they are naturally occurring compounds, which have good environmental sustainability and biocompatibility.

[0015] (2) In practical applications, succinic acid or PEG as phase change energy storage raw materials are prone to uneven heat transfer and poor heat transfer effect, which can easily lead to reduced energy efficiency or heat concentration. Through screening, this invention found that when it is combined with carbon black and expanded perlite, it can significantly improve its heat transfer effect, effectively improving the heat transfer effect (thermal conductivity reaches above 0.7 W / (m·K)) while maintaining a low phase change temperature.

[0016] (3) The solar phase change energy storage material of the present invention has excellent phase change potential, reaching 179 kJ·kg⁻¹. -1 The above-mentioned technologies can absorb or release a large amount of heat during the phase change process, which helps to store more energy, thereby improving the energy density and performance of the energy storage system.

[0017] In some embodiments of the present invention, the raw materials for preparing the first composite layer include, by weight, 8 to 12 parts of decanoic acid or polyethylene glycol, 0.5 to 1.5 parts of carbon black and 0.008 to 0.01 parts of surfactant.

[0018] In some embodiments of the present invention, the raw materials for preparing the second composite layer include, by weight, 40 to 80 parts of succinic acid or polyethylene glycol, and 0.5 to 1.5 parts of expanded perlite.

[0019] In some embodiments of the present invention, the molecular weight of the polyethylene glycol is 1500 to 1800.

[0020] The phase transition temperature of polyethylene glycol is positively correlated with its molecular weight. When its molecular weight is greater than a set range, the phase transition temperature will be higher, which is not conducive to improving the low-temperature heat storage capacity.

[0021] In some embodiments of the present invention, the first composite layer is located on the surface of the second composite layer.

[0022] In some embodiments of the present invention, the surfactant is selected from at least one of sodium dodecylbenzene sulfate, sodium cholate, and hexadecyltrimethylammonium bromide.

[0023] In some embodiments of the present invention, the bulk density of the expanded perlite is 70–80 kg / m³. 2 .

[0024] This invention selects expanded perlite as a carrier for phase change materials, which helps to improve energy storage efficiency. Furthermore, due to its good hygroscopic properties, it can quickly absorb the moisture released from the liquid phase change material, thereby improving the efficiency of the phase change material.

[0025] In some embodiments of the present invention, the thickness ratio of the first composite layer to the second composite layer is 1:15 to 30.

[0026] A second aspect of the present invention provides a method for preparing a solar phase change energy storage material as described in any one of the first aspects, comprising the following steps:

[0027] S1. Mix the raw materials for preparing the first composite layer according to the weight parts to obtain a first mixture for later use;

[0028] S2. Mix the raw materials for preparing the second composite layer according to the weight parts, and mold them to obtain the second composite layer. Then, bring the first mixture into contact with the surface of the second composite layer and mold it to obtain the final product.

[0029] The preparation method according to the embodiments of the present invention has at least the following beneficial effects: the preparation method of the present invention is simple, the raw materials are widely available, and the preparation process is pollution-free, making it suitable for industrial production.

[0030] In some embodiments of the present invention, in step S1, the mixing includes: heating the decanoic acid or polyethylene glycol until melted, then adding the carbon black and surfactant, and mixing thoroughly.

[0031] In some embodiments of the present invention, in step S2, the mixing includes: heating the succinic acid or polyethylene glycol until melted, then adding the expanded perlite and mixing thoroughly.

[0032] In some embodiments of the present invention, the heating temperature is 40–55°C.

[0033] In some embodiments of the present invention, the compression molding pressure is 30 to 80 MPa.

[0034] A third aspect of the present invention provides a solar thermal phase change energy storage tile comprising the solar phase change energy storage material described in any one of the first aspects.

[0035] In some embodiments of the present invention, the solar thermal phase change energy storage tile comprises a heat collection module, a phase change energy storage module, an insulation layer and an outer shell, wherein the phase change energy storage module comprises the solar phase change energy storage material.

[0036] In some embodiments of the present invention, the heat collection module includes a vacuum glass plate and a heat absorption plate.

[0037] In some embodiments of the present invention, the phase change energy storage module further includes a U-shaped finned tube.

[0038] A fourth aspect of the present invention provides the application of the solar phase change energy storage material as described in any of the first aspects or the preparation method as described in any of the second aspects in the preparation of energy storage materials.

[0039] In some embodiments of the present invention, the energy storage material includes a solar collector plate.

[0040] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0041] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0042] The terms "preferred," "more preferably," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0043] In the description of this invention, the reference term "and / or" includes all and any combination of one or more of the associated listed items.

[0044] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] Unless otherwise specified, "about" in this invention means that the allowable error is within ±2%.

[0046] Unless otherwise specified, "room temperature" in this invention means 25℃±5℃.

[0047] In an embodiment of the present invention, the carbon black was purchased from CABOT, and the model number was [missing information]. XC72; Expanded perlite of grade 70 (refer to JC / T 209-2012 standard) with a bulk density of 70-80 kg / m³. 2 The humidity is below 2%.

[0048] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0049] Example 1

[0050] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0051] The first composite layer, the raw materials for which this layer is prepared, by weight, include: 10 parts octanoic acid, 1 part carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0052] The second composite layer, which is the lower layer, is made from raw materials including, by weight, 50 parts octanoic acid and 1 part expanded perlite.

[0053] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0054] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0055] S1. Weigh out decanoic acid (CAS No.: 334-48-1, purity greater than 99%) according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0056] S2. Weigh out the octanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the octanoic acid. Then add the expanded perlite, mix well, and cool to room temperature for later use.

[0057] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0058] Example 2

[0059] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0060] The first composite layer, the raw materials for which are prepared include, by weight, 10 parts octanoic acid, 0.5 parts carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0061] The second composite layer, which is the lower layer, is made from raw materials including, by weight, 50 parts octanoic acid and 1 part expanded perlite.

[0062] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0063] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0064] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0065] S2. Weigh out the octanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the octanoic acid. Then add the expanded perlite, mix well, and cool to room temperature for later use.

[0066] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0067] Example 3

[0068] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0069] The first composite layer, the raw materials for which are prepared include, by weight, 10 parts octanoic acid, 1.2 parts carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0070] The second composite layer, which is the lower layer, is made from raw materials including, by weight, 50 parts octanoic acid and 1 part expanded perlite.

[0071] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0072] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0073] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0074] S2. Weigh out the octanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the octanoic acid. Then add the expanded perlite, mix well, and cool to room temperature for later use.

[0075] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0076] Example 4

[0077] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0078] The first composite layer, the raw materials for which this layer is prepared, by weight, include: 10 parts octanoic acid, 1 part carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0079] The second composite layer, which is the lower layer, is made from the following raw materials by weight: 50 parts octanoic acid and 0.5 parts expanded perlite.

[0080] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0081] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0082] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0083] S2. Weigh out the octanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the octanoic acid. Then add the expanded perlite, mix well, and cool to room temperature for later use.

[0084] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0085] Example 5

[0086] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0087] The first composite layer, the raw materials for which this layer is prepared, by weight, include: 10 parts octanoic acid, 1 part carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0088] The second composite layer, which is the lower layer, is made from the following raw materials by weight: 50 parts octanoic acid and 1.5 parts expanded perlite.

[0089] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0090] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0091] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0092] S2. Weigh out the octanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the octanoic acid. Then add the expanded perlite, mix well, and cool to room temperature for later use.

[0093] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0094] Example 6

[0095] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0096] The first composite layer, the raw materials for which are prepared include, by weight, 10 parts octanoic acid, 1 part carbon black and 0.01 parts sodium dodecylbenzene sulfate;

[0097] The second composite layer, which is the lower layer, is made from raw materials including, by weight, 50 parts octanoic acid and 1 part expanded perlite.

[0098] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0099] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0100] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0101] S2. Weigh out the octanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the octanoic acid. Then add the expanded perlite, mix well, and cool to room temperature for later use.

[0102] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0103] Example 7

[0104] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0105] The first composite layer, the raw materials for which are prepared include, by weight, 10 parts polyethylene glycol 1500 (PEG1500), 1 part carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0106] The second composite layer, which is the lower layer, is made from raw materials including, by weight, 50 parts PEG1500 and 1 part expanded perlite.

[0107] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0108] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0109] S1. Weigh out PEG1500 according to the above weight proportions, and heat it at 45°C to completely melt PEG1500. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0110] S2. Weigh out PEG1500 according to the above weight proportions, and heat it at 45°C to completely melt PEG1500. Then add expanded perlite, mix well, and cool to room temperature for later use.

[0111] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0112] Example 8

[0113] This embodiment provides a solar thermal phase change energy storage tile, which mainly comprises a heat collection module, a phase change energy storage module, an insulation layer, and an outer shell. The heat collection module includes a vacuum glass plate and a heat absorption plate, and the phase change energy storage module includes the solar phase change energy storage material of this invention and a U-shaped finned tube.

[0114] Understandably, when sunlight shines directly on the solar thermal phase change energy storage tile, the light passes through the vacuum glass plate and reaches the heat absorber. At this point, the heat absorber converts solar energy into heat energy, which is then transferred to the energy storage module. Once the heat reaches the energy storage module, a portion is stored as latent heat of phase change by the solar thermal phase change energy storage material of this invention, while the other portion is transferred to the water in the U-shaped finned tube. The water in the finned tube flows into an external water tank at a certain flow rate, transferring heat to the external water tank. The water, after releasing heat, returns to the finned tube to absorb heat again. In the evening, when the ambient temperature drops, the solar thermal phase change energy storage material of the solar thermal phase change energy storage tile begins to release heat, releasing the stored energy for heating.

[0115] Comparative Example 1

[0116] This comparative example provides a solar phase change energy storage material and its preparation method. The raw materials for preparing the solar phase change energy storage material, by weight, include: 10 parts of octanoic acid, 4 parts of carbon black, and 0.01 parts of hexadecyltrimethylammonium bromide. The thickness of the solar phase change energy storage material is approximately 0.1 cm.

[0117] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0118] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0119] S2. Place the mixed material from the above steps into a mold and compact it under a pressure of 50MPa to obtain the solar phase change energy storage material.

[0120] Comparative Example 2

[0121] This comparative example provides a solar phase change energy storage material and its preparation method. The raw materials for preparing the solar phase change energy storage material, by weight, include: 50 parts of octanoic acid and 1 part of expanded perlite. The thickness of the solar phase change energy storage material is approximately 2 cm.

[0122] The preparation methods of the above-mentioned solar phase change energy storage materials include:

[0123] Weigh out the octanic acid according to the above-mentioned weight proportions, and heat it at 45°C to completely melt the octanic acid. Then add expanded perlite, mix well, and cool to room temperature. Then pour the mixture into a mold and mold it under a pressure of 50MPa to obtain the solar phase change energy storage material.

[0124] Comparative Example 3

[0125] This comparative example provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0126] The first composite layer, the raw materials for which are prepared include, by weight, 10 parts stearic acid, 4 parts carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0127] The second composite layer, which is the lower layer, is made from the following raw materials by weight: 50 parts stearic acid and 1 part expanded perlite.

[0128] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0129] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0130] S1. Weigh stearic acid (CAS No.: 57-11-4, purity greater than 99%) according to the above weight proportions, and heat it at 45°C to completely melt the stearic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0131] S2. Weigh out stearic acid according to the above weight proportions, and heat it at 45°C to completely melt the stearic acid. Then add expanded perlite, mix well, and cool to room temperature for later use.

[0132] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0133] Comparative Example 4

[0134] This embodiment provides a solar phase change energy storage material and its preparation method. The solar phase change energy storage material includes:

[0135] The first composite layer, the raw materials for which this layer is prepared, by weight, include: 10 parts octanoic acid, 4 parts carbon black and 0.01 parts hexadecyltrimethylammonium bromide;

[0136] The second composite layer, which is the lower layer, is made from raw materials including, by weight, 50 parts octanoic acid and 1 part expanded graphite.

[0137] The thickness of the first composite layer of the solar phase change energy storage material is about 0.1 cm, and the thickness of the second composite layer is about 2 cm.

[0138] The preparation method of the above-mentioned solar phase change energy storage material includes the following steps:

[0139] S1. Weigh the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add carbon black and stir evenly. Add hexadecyltrimethylammonium bromide and continue stirring. Let it cool naturally to room temperature and keep it warm for later use.

[0140] S2. Weigh out the decanoic acid according to the above weight proportions, and heat it at 45°C to completely melt the decanoic acid. Then add expanded graphite, mix well, and cool to room temperature for later use.

[0141] S3. Place the mixed material from step S2 into a mold and compact it under a pressure of 50 MPa. Then, pour the mixture obtained in step S1 evenly onto its surface. After it cools to room temperature, mold it under a pressure of 50 MPa to obtain the solar phase change energy storage material.

[0142] Test Example 1: Thermal Conductivity Test

[0143] This test example tested the thermal conductivity of the solar phase change energy storage materials prepared in Examples 1-7 and Comparative Examples 1-4. At the same time, octanoic acid was used as a control group. The thermal conductivity at 28℃ and 60℃ was tested respectively. The thermal conductivity at 28℃ is the solid thermal conductivity and the thermal conductivity at 30℃ is the liquid thermal conductivity. The test results are shown in Table 1.

[0144] Table 1: Thermal conductivity test results

[0145]

[0146]

[0147] The results above show that the solar phase change energy storage material prepared by this invention has excellent thermal conductivity, which is approximately 421.23% higher than that of the control group (capric acid) and 18.5% higher than that of a single-layer phase change material (such as the capric acid-carbon black layer in Comparative Example 1). Therefore, the solar phase change energy storage material of this invention can be selected as a preferred thermally conductive material. Furthermore, capric acid, as the main phase change energy storage material, has a higher low-temperature thermal conductivity than PEG1500.

[0148] Test Example 2: Phase Change Performance Testing

[0149] The ability of solar phase change energy storage materials to store and release thermal energy is directly related to their phase change temperature and phase change potential. This test example tested the phase change temperature and phase change potential of the solar phase change energy storage materials prepared in Examples 1-7 and Comparative Examples 1-4. The test results are shown in Table 2. A lower phase change temperature indicates that even under relatively low solar radiation conditions, the latent heat of phase change can be effectively utilized to store energy; a higher phase change potential indicates that the energy storage material can absorb or release a large amount of heat during the phase change process, which helps to improve energy storage efficiency.

[0150] Table 2: Phase Change Performance Test Results

[0151]

[0152] The test results above show that the solar phase change energy storage material of the present invention has a low phase change temperature, approximately between 32 and 33.5°C, which is much lower than that of solar phase change energy storage materials made with stearic acid. In addition, the test results above show that when carbon black or expanded perlite is added, although the phase change potential is improved to a certain extent, the corresponding phase change temperature also increases to varying degrees. This is presumably related to pressure or the resulting changes in ambient humidity. For example, when the content of expanded perlite increases, it is easy to cause a decrease in the surrounding humidity, which in turn affects the phase change temperature.

[0153] Secondly, as can be seen from the above results, compared with Example 1, the phase change potential of Comparative Example 1 and Comparative Example 2 decreased to different degrees. It is generally believed that the phase change latent heat is the key to the storage and release of energy in the energy storage system. Materials with a large phase change latent heat can absorb or release more energy during the phase change process, thereby increasing the energy storage capacity. Therefore, when the phase change latent heat decreases, it indicates that its energy storage capacity or energy storage efficiency decreases. In the solar phase change energy storage material of the present invention, when the urethane-carbon black composite layer or the urethane-expanded perlite composite layer is removed, the corresponding heat absorption and release capacity also decreases, which in turn leads to a decrease in the phase change latent heat.

[0154] Furthermore, compared to Example 1, Example 7 used PEG1500 as the main phase change energy storage material. Although the phase change temperature was higher than that of decanoic acid in Example 1, the phase change potential was higher, reaching 195.64 kJ·kg⁻¹. -1 It is speculated that this is related to its molecular structure.

[0155] In summary, this invention provides a customized roof-shaped solar energy material, its preparation method, and its application. The solar energy material of this invention is a solar phase change energy storage material, comprising a first composite layer and a second composite layer. The first composite layer is the upper layer, and its preparation raw materials include succinic acid (or PEG1500), carbon black, and a surfactant. The second composite layer is the lower layer, and its preparation raw materials include succinic acid (or PEG1500) and expanded perlite. The test results show that it has excellent thermal conductivity, with a thermal conductivity of approximately 0.71–0.81 W / (m·K). Furthermore, the phase change temperature and phase change potential test results show that its phase change temperature is approximately 32–33.5℃, and its phase change potential is 179 kJ·kg⁻¹. -1 The above demonstrates that the solar phase change energy storage material of the present invention can effectively utilize the latent heat of phase change to store energy even under relatively low solar radiation conditions, and can be widely used in the preparation of rooftop solar thermal phase change energy storage tiles.

[0156] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A method for preparing a solar phase change energy storage material, characterized in that, Includes the following steps: S1. Mix the raw materials for preparing the first composite layer according to the weight parts to obtain the first mixture for later use; S2. Mix the raw materials for the preparation of the second composite layer according to the weight parts, and mold them to obtain the second composite layer. Then, bring the first mixture into contact with the surface of the second composite layer, and mold it to obtain the final product. The raw materials for preparing the first composite layer consist of 8-12 parts of decanoic acid or polyethylene glycol, 0.5-1.5 parts of carbon black, and 0.008-0.015 parts of surfactant; the surfactant is selected from at least one of sodium dodecylbenzene sulfate, sodium cholate, and hexadecyltrimethylammonium bromide. The second composite layer is prepared from 40-80 parts of succinic acid or polyethylene glycol and 0.5-2 parts of expanded perlite. The molecular weight of the polyethylene glycol is 1500~2000; the thickness ratio of the first composite layer to the second composite layer is 1:15~30.

2. The preparation method according to claim 1, characterized in that, In step S1, the mixing includes: heating the decanoic acid or polyethylene glycol until melted, then adding the carbon black and surfactant, and mixing thoroughly.

3. The preparation method according to claim 2, characterized in that, In step S2, the mixing includes: heating the succinic acid or polyethylene glycol until melted, then adding the expanded perlite and mixing well.

4. The preparation method according to claim 2 or 3, characterized in that, The heating temperature is 40~55℃; and / or the molding pressure is 30~80MPa.

5. A solar thermal phase change energy storage tile, characterized in that, The solar phase change energy storage material is prepared by the preparation method according to any one of claims 1 to 4.

6. The application of the solar phase change energy storage material prepared by the preparation method according to any one of claims 1 to 4 in the preparation of energy storage materials.

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