A rock wool / calcium chloride hexahydrate-based thermal insulation wallboard and a preparation method thereof

Abstract

This invention belongs to the field of thermal insulation wall panel technology, and discloses a rock wool / calcium chloride hexahydrate-based thermal insulation wall panel and its preparation method. A thermally modulating rock wool panel is prepared using a compounded calcium chloride hexahydrate-based phase change material as the energy storage material and rock wool board as the carrier of the phase change energy storage material. The energy storage and thermal insulation performance of the rock wool board is modified through the coupling of the rock wool board and the phase change material, maximizing the utilization rate of the phase change material. Test experiments show that the thermally modulating rock wool panel containing 30 wt.% calcium chloride hexahydrate-based phase change energy storage material can effectively achieve the maximum adsorption capacity and prevent leakage; at the same time, it has a good improvement in overall thermal insulation performance; and compared with pure rock wool panel rooms, the thermally modulating rock wool panel room has better energy storage and thermal insulation capabilities, and can also more efficiently improve human thermal comfort conditions, achieving energy saving and consumption reduction effects. The addition of calcium chloride hexahydrate-based phase change energy storage material improves the compressive strength and enhances the mechanical strength of the rock wool panel.

Description

Technical Field

[0001] This invention belongs to the field of thermal insulation wall panel technology, and particularly relates to a rock wool / calcium chloride hexahydrate-based thermal insulation wall panel and its preparation method. Background Technology

[0002] Currently, improving the performance of building envelopes is an effective measure to save energy and increase energy efficiency. In recent years, phase change materials (PCMs) have been widely adopted due to their high latent heat of phase change, suitable phase change temperature, stable chemical properties, good reversibility of phase change process, and environmental friendliness. They are typically added to traditional building materials such as gypsum board, mortar, or concrete using methods such as direct addition, impregnation, and encapsulation to prepare new building materials. When PCMs are used in building exterior envelopes, they melt and absorb heat from the walls during the day and slowly release heat to the environment and interior during the night when they cool and solidify, thus maintaining a stable indoor temperature. The main heat transfer methods in buildings include convection, radiation, and conduction, with conduction accounting for a large proportion of building heat. Numerous studies have shown that adding PCMs to building envelopes can utilize their phase change energy storage and insulation functions to reduce indoor temperature fluctuations and lower building energy costs, significantly improving indoor comfort. For example, Qian et al. used a suspension of phase change material (SPCM) instead of water as a coolant to cool the internal temperature rise of concrete. Test results showed that SPCM as a coolant could increase the temperature drop of concrete by 27%–28% and reduce the temperature difference by 7.6%–8.4%. Yang et al. used porous ceramsite to adsorb a binary mixture of lauryl alcohol and stearic acid to prepare a composite phase change material, which was then added to concrete to prepare phase change energy storage concrete. Their research showed that when the content of phase change material in the concrete was 15 wt.%, the phase change energy storage concrete possessed both excellent heat storage capacity and met mechanical strength requirements. Jayalath et al. added paraffin-based microcapsules to mortar and concrete to prepare phase change energy storage mortar. The results showed that as the volume fraction of paraffin-based microcapsules increased, the thermal conductivity of the phase change energy storage mortar decreased, the specific heat capacity increased, but the mechanical strength decreased, and the optimal volume fraction of paraffin-based microcapsules was 20%. Bake et al. prepared phase change gypsum board by mixing paraffin / highly cross-linked polymethyl methacrylate phase change microcapsules with gypsum as the matrix. The experimental results showed that the higher the content of phase change microcapsules, the lower the compressive strength of the phase change gypsum board, but the energy storage increased by 0.4 W / min compared with ordinary gypsum board.

[0003] Calcium chloride hexahydrate (CaCl2·6H2O) and magnesium chloride hexahydrate (MgCl2·6H2O) are typical inorganic hydrated salt phase change energy storage materials, widely used in building materials due to their high energy storage density and suitable phase change temperature. Li et al. prepared form-stable phase change materials (FSPCMs) by adsorbing calcium chloride hexahydrate with nano-SiO2. Test results showed that this composite phase change material could not only reduce the peak indoor temperature but also extend the indoor insulation time. Zeng et al. prepared a form-stable composite phase change material using calcium chloride hexahydrate and expanded graphite, and applied it to polyvinyl chloride (PVC) boards to obtain PCM and PVC composite boards. Studies found that this composite board could maintain room temperature at 24.5℃~27.5℃ for a long time. These studies indicate that composite PCMs have good application prospects in building energy conservation. Rock wool, due to its good fire resistance and durability, and as a Class A non-combustible material, is one of the most widely used inorganic insulation materials in building envelopes.

[0004] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0005] 1) Poor thermal insulation performance: Traditional rock wool boards have certain limitations in terms of thermal insulation. Their thermal conductivity is relatively high, resulting in rapid heat transfer and unsatisfactory insulation effects. This leads to buildings requiring more energy for winter insulation, increasing energy costs.

[0006] 2) High energy consumption: Due to the limited thermal insulation performance of traditional rock wool boards, in order to meet the thermal insulation requirements of buildings, it is necessary to increase the operation of heating or cooling equipment, thereby increasing energy consumption and making the building's energy consumption high.

[0007] 3) Large fluctuations in indoor temperature: Traditional rock wool boards have limited effectiveness in heat storage and release, and cannot effectively regulate indoor temperature. This leads to large fluctuations in the building's internal temperature, affecting indoor comfort and energy efficiency.

[0008] 4) Insufficient durability: Traditional rock wool boards have relatively poor durability and are easily affected by environmental factors such as humidity and temperature. They are prone to moisture, aging, corrosion, etc., which affects their service life.

[0009] 5) Release of harmful substances: During the preparation process of traditional rock wool boards, harmful gases or particulate matter may be released, posing potential hazards to human health and the environment.

[0010] In summary, traditional rock wool boards have drawbacks and problems in building energy conservation, including poor thermal insulation performance, high energy consumption, large indoor temperature fluctuations, insufficient durability, and the potential release of harmful substances. Therefore, it is necessary to seek new technical solutions and new materials to improve the performance and energy efficiency of building envelopes. Summary of the Invention

[0011] To address the problems existing in the prior art, this invention provides a rock wool / calcium chloride hexahydrate-based thermal insulation wall panel and its preparation method.

[0012] This invention is achieved by a method for preparing a rock wool / calcium chloride hexahydrate-based thermal insulation wall panel, which combines a calcium chloride hexahydrate-based phase change energy storage material with a rock wool board to form a thermally modulating rock wool board. By optimizing the composition and preparation process of the phase change energy storage material, and by using a silane coupling agent to enhance the material bonding, the high thermal insulation performance and thermally modulating capability of the thermal insulation wall panel are achieved, resulting in a novel high-efficiency thermal insulation material.

[0013] Furthermore, the preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel is to prepare a thermally regulating rock wool panel by coupling rock wool board and phase change energy storage material. The phase change energy storage material is calcium chloride hexahydrate-based, wherein calcium chloride hexahydrate (CaCl2·6H2O) is the main phase change material, and 10 wt.% magnesium chloride hexahydrate (MgCl2·6H2O), 2 wt.% strontium chloride hexahydrate (SrCl2·6H2O) and 1 wt.% carboxymethyl cellulose (CMC) are added to it; the rock wool board is the carrier of the phase change energy storage material.

[0014] Furthermore, the preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel energy storage material is to heat calcium chloride hexahydrate to 50°C in a water bath and then add magnesium chloride hexahydrate, strontium chloride hexahydrate and carboxymethyl cellulose to prepare calcium chloride hexahydrate-based phase change energy storage material.

[0015] Furthermore, the preparation method of calcium chloride hexahydrate-based phase change energy storage material is as follows:

[0016] Calcium chloride hexahydrate was heated to 50°C and completely melted in a container. The following materials were then added according to an orthogonal scheme:

[0017] Add 10–30 wt.% magnesium chloride hexahydrate;

[0018] Add 1.0–3.0 wt.% strontium chloride hexahydrate;

[0019] Add 0.5–1.5 wt.% carboxymethyl cellulose;

[0020] Mix thoroughly.

[0021] Furthermore, modified solutions were prepared by adding calcium chloride hexahydrate-based phase change energy storage material at mass fractions of 8–12 wt.%, 18–22 wt.%, 28–32 wt.%, and 38–42 wt.% of anhydrous ethanol, respectively, using anhydrous ethanol as a solvent.

[0022] Furthermore, after adding silane coupling agent KH500 to the modified solution, it is brushed onto the surface of the rock wool board, and brushing is stopped when the penetration depth of the modified solution reaches 20mm.

[0023] Furthermore, the coated rock wool board was placed in a fume hood for 24 hours to evaporate at room temperature, and then placed in a 40℃ forced-air drying oven to dry at normal pressure for 24 hours until completely dry, thus preparing a thermally functional rock wool board composite of rock wool / calcium chloride hexahydrate-based phase change material.

[0024] Furthermore, the preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel also includes:

[0025] The maximum adsorption capacity of the thermally adjustable rock wool board for phase change material was determined by a liquid leakage test.

[0026] The thermal conductivity of the heat-regulating rock wool board was measured using the double-plate protective hot plate balance method, and the specific heat capacity and thermal diffusivity were measured using a thermal constant analyzer (Hot disk method).

[0027] The energy storage and insulation capacity of the thermally regulating rock wool board was tested using the room structure and thermocouples.

[0028] The compressive strength of the heat-regulating rock wool board was determined using a universal testing machine.

[0029] The microstructure of the thermally regulated rock wool board was characterized by morphology analysis (SEM).

[0030] Furthermore, the specific process of the liquid leakage experiment is as follows:

[0031] Place the thermally modulating rock wool board containing different mass fractions of calcium chloride hexahydrate-based phase change energy storage material on four clean filter papers and heat it continuously in a drying oven at 50°C for one hour. After the calcium chloride hexahydrate-based phase change material has completely melted and turned into a liquid phase, carefully observe whether there is any liquid residue on the filter paper.

[0032] Furthermore, the internal space of the chamber is 30cm×30cm×30cm, and a 100W heat source is set at the top 35cm of the chamber to simulate sunlight; the walls of the chamber are composed of a rock wool board (30cm×30cm×5cm) and five EPS boards; temperature sensors are placed at the center of the inner surface of the rock wool board and at the center of the chamber, and are connected to their respective temperature recorders to record temperature changes.

[0033] Furthermore, the specific process of testing the thermal function regulating rock wool board using the chamber body and thermocouples is as follows:

[0034] First, adjust the room temperature to 20°C, then turn on the simulated heat source above the chamber and heat for 2 hours to ensure that the calcium chloride hexahydrate-based phase change energy storage material in the rock wool board reaches or exceeds the phase change temperature; turn off the simulated heat source and test the curve of the chamber automatically cooling to room temperature. During cooling, the temperature change is also recorded by a temperature recorder.

[0035] Furthermore, the specific process of characterizing the microstructure of the thermally regulated rock wool board using morphology analysis (SEM) is as follows:

[0036] After the thermally adjustable rock wool board was subjected to gold sputtering in a vacuum environment, its microstructure and surface morphology were observed at room temperature using a JEOL JSM-6701F field emission scanning electron microscope (SEM) with an accelerating voltage of 20 kV.

[0037] Another object of the present invention is to provide a method for preparing the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel.

[0038] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0039] First, the thermally modulating rock wool board containing 30 wt.% calcium chloride hexahydrate-based phase change energy storage material provided by this invention can effectively achieve the maximum adsorption capacity of the calcium chloride hexahydrate-based phase change energy storage material and prevent leakage. Simultaneously, while the thermal conductivity of the rock wool board increases due to the calcium chloride hexahydrate-based phase change energy storage material, it effectively improves its overall insulation performance. Furthermore, compared to pure rock wool board rooms, the thermally modulating rock wool board room has better energy storage and insulation capabilities, can more efficiently improve human thermal comfort, and achieves energy saving and consumption reduction effects. The addition of calcium chloride hexahydrate-based phase change energy storage material significantly improves the compressive strength of the rock wool board, thereby enhancing its mechanical strength.

[0040] Second, considering the technical solution as a whole or from a product perspective, the technical effects and advantages of the technical solution to be protected by this invention are specifically described as follows:

[0041] (1) Through liquid leakage experiments, the maximum adsorption capacity of the rock wool board for calcium chloride hexahydrate-based phase change energy storage material was determined to be 30 wt.%. When the content of phase change material exceeds 30 wt.%, adsorption saturation is reached, and crystallization occurs on the outer wall of the rock wool fibers. SEM results show that the composite phase change material adheres to the rock wool fiber wall and fiber voids, forming a stable and highly resilient spatial grid structure, which enhances the mechanical strength of the rock wool board. The higher the mass percentage of calcium chloride hexahydrate-based phase change energy storage material, the higher the mechanical strength of the thermally modulated rock wool board.

[0042] (2) The higher the content of calcium chloride hexahydrate-based phase change energy storage material, the higher the specific heat capacity and the lower the thermal diffusivity of the thermally adjustable rock wool board. However, the drawback is that the thermal conductivity of the thermally adjustable rock wool board is higher. The above results indicate that the addition of calcium chloride hexahydrate-based phase change energy storage material has both positive and negative effects on the thermal performance of the rock wool board. However, the increase in the specific heat capacity and thermal density of the thermally adjustable rock wool board reduces the thermal diffusivity of the thermally adjustable rock wool board, and the overall thermal insulation performance is significantly enhanced.

[0043] (3) The test results of the building body show that with the increase of calcium chloride hexahydrate-based phase change energy storage materials, the energy storage and heat insulation capacity of rock wool boards is enhanced, the temperature fluctuation at the center of the building body is smaller, and the rate of temperature rise and fall at the center of the building body becomes more gradual, which is conducive to energy conservation and consumption reduction of buildings. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the heat transfer performance test of the chamber provided in an embodiment of the present invention.

[0045] Figure 2 These are digital photographs of liquid leakage experiments on rock wool boards with different mass fractions of calcium chloride hexahydrate-based phase change energy storage materials provided in embodiments of the present invention. Figure 2 (a) is a test graph showing that the adsorption capacity of rock wool reaches its maximum value when the mass fraction of the modified solution of calcium chloride hexahydrate-based phase change energy storage material is 30 wt.%. Figure 2 (b) shows a photograph of thermally modulated rock wool boards with different mass fractions of calcium chloride hexahydrate-based phase change energy storage materials during a liquid leakage test. Figure 2 (c) Photograph of crystal precipitation when 40 wt.% calcium chloride hexahydrate-based phase change energy storage material is added.

[0046] Figure 3 The parameters of the thermally adjustable rock wool board provided in this embodiment of the invention are: (a) specific heat capacity, (b) thermal conductivity, and (c) thermal diffusivity.

[0047] Figure 4 These are temperature change curves of rock wool boards with different contents of calcium chloride hexahydrate-based phase change energy storage materials for thermal function regulation provided in the embodiments of the present invention. (a) Temperature curve of the inner surface of the rock wool board, and (b) Temperature curve of the center of the chamber.

[0048] Figure 5 The thermal function of rock wool boards with different mass fractions of calcium chloride hexahydrate-based phase change energy storage materials, as provided in the embodiments of the present invention, is adjusted to improve their compressive strength.

[0049] Figure 6 The images show the SEM microstructures of pure rock wool board and heat-adjustable rock wool board provided in the embodiments of the present invention: (a) pure rock wool board, (b) heat-adjustable rock wool board, and (c) heat-adjustable rock wool boards with different contents.

[0050] Figure 7 Cooling curve of calcium chloride hexahydrate provided in this embodiment of the invention.

[0051] Figure 8 Digital photograph of calcium chloride hexahydrate crystals provided in this embodiment of the invention.

[0052] Figure 9 Cooling curves of calcium chloride hexahydrate-based phase change energy storage materials S-1 to S-4 provided in this embodiment of the invention.

[0053] Figure 10 Cooling curves of calcium chloride hexahydrate-based phase change energy storage materials S-5 to S-9 provided in this embodiment of the invention.

[0054] Figure 11 The trend chart of the average supercooling value of the calcium chloride hexahydrate-based phase change energy storage material provided in the embodiments of the present invention at the same level.

[0055] Figure 12 The trend of average phase change temperature of the calcium chloride hexahydrate-based phase change energy storage material provided in this embodiment of the invention at the same level. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0057] In this embodiment of the invention, calcium chloride hexahydrate-based phase change energy storage material is combined with rock wool board to form a thermally regulating rock wool board. By optimizing the composition and preparation process of the phase change energy storage material, and by using a silane coupling agent to enhance the material bonding, the high thermal insulation performance and thermal regulation capability of the insulation wall panel are achieved, resulting in a new type of high-efficiency thermal insulation material.

[0058] The present invention provides a method for preparing a rock wool / calcium chloride hexahydrate-based thermal insulation wall panel. The method involves coupling a rock wool board and a phase change energy storage material to prepare a thermally regulating rock wool board. The rock wool board uses calcium chloride hexahydrate-based phase change energy storage material, with calcium chloride hexahydrate (CaCl2·6H2O) as the main phase change material. Additionally, 10 wt.% magnesium chloride hexahydrate (MgCl2·6H2O), 2 wt.% strontium chloride hexahydrate (SrCl2·6H2O), and 1 wt.% carboxymethyl cellulose (CMC) are added. The rock wool board serves as the carrier for the phase change energy storage material.

[0059] Rock wool board (non-combustible grade A, thermal conductivity (room temperature) 0.048 W / (m·k), provided by Gansu Construction Investment (Holding) Group Co., Ltd.); anhydrous ethanol (analytical grade AR); silane coupling agent (KH550 analytical grade AR, Tianjin Tianli Chemical Reagent Co., Ltd.); calcium chloride hexahydrate (CaCl2·6H2O, phase change temperature 29.92℃, latent heat of phase change 191 J / g, purity ≥98%, analytical grade AR, Tianjin Jinhui Taiya Chemical Reagent Co., Ltd.); magnesium chloride hexahydrate (MgCl2·6H2O, phase change temperature 117℃, latent heat of phase change 160 J / g, purity ≥99%, analytical grade AR, Sinopharm Chemical Reagent Co., Ltd.); strontium chloride hexahydrate (SrCl2·6H2O) and carboxymethyl cellulose (CMC) were all purchased from Sinopharm Chemical Reagent Co., Ltd.

[0060] A method for preparing rock wool / calcium chloride hexahydrate-based thermal insulation wall panels involves preparing modified solutions of calcium chloride hexahydrate-based phase change energy storage materials at mass fractions of 10 wt.%, 20 wt.%, 30 wt.%, and 40 wt.% relative to anhydrous ethanol.

[0061] Silane coupling agent KH500 was added to the modified solution to enhance its adhesion. The modified solution was then brushed onto the surface of the rock wool board, and brushing was stopped when the penetration depth of the modified solution reached 20 mm.

[0062] The prepared thermally adjustable rock wool board was placed in a fume hood for 24 hours to volatilize at room temperature, and then placed in a 40℃ forced-air drying oven for 24 hours to dry completely, thus preparing a thermally adjustable rock wool board composite of rock wool / calcium chloride hexahydrate-based phase change material.

[0063] The preparation method of rock wool / calcium chloride hexahydrate-based thermal insulation wall panels also includes the preparation of calcium chloride hexahydrate-based phase change energy storage materials;

[0064] Calcium chloride hexahydrate is heated in a container until completely melted;

[0065] Add 10 wt.% magnesium chloride hexahydrate;

[0066] Add 2 wt.% strontium chloride hexahydrate;

[0067] Add 1 wt.% carboxymethyl cellulose;

[0068] Mix thoroughly.

[0069] The preparation method of rock wool / calcium chloride hexahydrate-based thermal insulation wall panel also includes determining the maximum adsorption capacity of rock wool board for phase change material through liquid leakage test;

[0070] The thermal conductivity of the heat-regulating rock wool board was measured using the double-plate protective hot plate balance method, and the specific heat capacity and thermal diffusivity were measured using a thermal constant analyzer (Hot disk method).

[0071] The energy storage and insulation capacity of the thermally regulating rock wool board was tested using the room structure and thermocouples.

[0072] The compressive strength of the heat-regulating rock wool board was determined using a universal testing machine.

[0073] The microstructure of the thermally regulated rock wool board was characterized by morphology analysis (SEM).

[0074] The specific procedure for the liquid leakage test is as follows:

[0075] Place the thermally modulating rock wool board containing different mass fractions of calcium chloride hexahydrate-based phase change energy storage material on four clean filter papers and heat it continuously in a drying oven at 50°C for one hour. After the calcium chloride hexahydrate-based phase change material has completely melted and turned into a liquid phase, carefully observe whether there is any liquid residue on the filter paper.

[0076] The interior space of the chamber is 30cm×30cm×30cm. A 100W heat source is set at the top 35cm of the chamber to simulate sunlight. The walls of the chamber are composed of a rock wool board (30cm×30cm×5cm) and five EPS boards. Temperature sensors are placed at the center of the inner surface of the rock wool board and at the center of the chamber, and are connected to their respective temperature recorders to record temperature changes.

[0077] The specific process for testing the thermal function regulating rock wool board in the room and using thermocouples is as follows:

[0078] First, adjust the room temperature to 20°C, then turn on the simulated heat source above the chamber and heat for 2 hours to ensure that the calcium chloride hexahydrate-based phase change energy storage material in the rock wool board reaches or exceeds the phase change temperature; turn off the simulated heat source and test the curve of the chamber automatically cooling to room temperature. During cooling, the temperature change is also recorded by a temperature recorder.

[0079] The specific process of characterizing the microstructure of the thermally conditioned rock wool board by morphology analysis (SEM) is as follows: After the thermally conditioned rock wool board is placed in a vacuum environment and sputtered with gold, the microstructure and surface morphology are observed at room temperature using a JEOL JSM-6701F field emission scanning electron microscope (SEM) with an accelerating voltage of 20kV.

[0080] This invention also provides a method for preparing rock wool / calcium chloride hexahydrate-based thermal insulation wall panels, resulting in rock wool / calcium chloride hexahydrate-based thermal insulation wall panels.

[0081] To demonstrate the inventiveness and technical value of the technical solution of this invention, this section provides specific product or related technology application examples of the technical solution claimed.

[0082] 1. Testing and Characterization

[0083] (1) The liquid leakage test can determine the maximum adsorption capacity of the rock wool board for the calcium chloride hexahydrate-based phase change energy storage material. The specific operation is as follows: place the thermal function regulating rock wool board containing different mass fractions of calcium chloride hexahydrate-based phase change energy storage material on 4 clean filter papers, and heat it continuously in a drying oven at 50°C for one hour. After the calcium chloride hexahydrate-based phase change energy storage material has completely melted and turned into a liquid phase, carefully observe whether there is any liquid residue on the filter paper.

[0084] (2) Determination of thermal conductivity, specific heat capacity and thermal diffusivity: According to GB / T10294-2008 "Determination of steady-state thermal resistance and related properties of thermal insulation materials", the thermal conductivity of the thermal function regulating plate was measured by the double-plate protective hot plate balance method, and the specific heat capacity and thermal diffusivity were measured by the hot disk method.

[0085] (3) Compressive strength test: According to GB / T13480 "Test method for compressibility of mineral wool products", the compressive strength of the heat-adjustable rock wool board was determined by using a universal testing machine.

[0086] (4) Test of the energy storage and heat insulation capacity of thermally regulating rock wool board

[0087] The energy storage and insulation capacity of the thermal regulating rock wool panels is tested through the building structure, such as... Figure 1As shown in the diagram, the internal space of the chamber is 30cm × 30cm × 30cm. A 100W heat source is placed 35cm above the chamber to simulate sunlight. The chamber walls consist of one rock wool board (30cm × 30cm × 5cm) and five EPS boards. Temperature sensors are placed at the center of the inner surface of the rock wool board and at the center of the chamber, and are connected to their respective temperature recorders to record temperature changes. The specific test procedure is as follows: first, the room temperature is adjusted to 20℃, then the simulated heat source above the chamber is turned on, and the heating time is 2 hours to ensure that the calcium chloride hexahydrate-based phase change energy storage material in the rock wool board reaches or exceeds the phase change temperature. Finally, the simulated heat source is turned off, and the curve of the chamber automatically cooling back to room temperature is tested. Temperature changes are also recorded by temperature recorders during cooling.

[0088] (5) Morphology analysis (SEM): After the thermally adjustable rock wool board was sputtered with gold in a vacuum environment, the microstructure and surface morphology were observed at room temperature using a JEOL JSM-6701F field emission scanning electron microscope (SEM) with an accelerating voltage of 20kV.

[0089] The following are two specific embodiments provided by the present invention:

[0090] Example 1:

[0091] 1) First, heat calcium chloride hexahydrate (CaCl2·6H2O) until it is completely melted.

[0092] 2) Add 10 wt.% magnesium chloride hexahydrate (MgCl2·6H2O), 2 wt.% strontium chloride hexahydrate (SrCl2·6H2O), and 1 wt.% carboxymethyl cellulose (CMC) to the melted calcium chloride hexahydrate and mix thoroughly.

[0093] 3) 20% calcium chloride hexahydrate-based phase change energy storage material, the rest is anhydrous ethanol.

[0094] 4) Immerse the rock wool board in the modified solution to allow it to fully absorb the phase change energy storage material.

[0095] 5) Remove the soaked rock wool board and let it air dry to the required humidity.

[0096] 6) Cut and arrange the dried rock wool boards to make the required rock wool / calcium chloride hexahydrate-based insulation wall panels.

[0097] Example 2:

[0098] 1) First, heat calcium chloride hexahydrate (CaCl2·6H2O) until it is completely melted.

[0099] 2) Add 10 wt.% magnesium chloride hexahydrate (MgCl2·6H2O), 2 wt.% strontium chloride hexahydrate (SrCl2·6H2O), and 1 wt.% carboxymethyl cellulose (CMC) to the melted calcium chloride hexahydrate and mix thoroughly.

[0100] 3) A modified solution of calcium chloride hexahydrate-based phase change energy storage material was prepared using 40 wt.% anhydrous ethanol.

[0101] 4) Immerse the rock wool board in the modified solution to allow it to fully absorb the phase change energy storage material.

[0102] 5) Remove the soaked rock wool board and let it air dry to the required humidity.

[0103] 6) Cut and arrange the dried rock wool boards to make the required rock wool / calcium chloride hexahydrate-based insulation wall panels.

[0104] In both embodiments, the preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel adopts the same preparation process, differing only in the mass fraction of anhydrous ethanol in the modifying solution. These two different mass fractions of anhydrous ethanol can affect the distribution and permeation degree of the phase change energy storage material in the rock wool panel, thereby adjusting the thermal regulation performance of the thermal insulation wall panel.

[0105] The embodiments of the present invention have achieved some positive results during the research and development or use process, and have indeed great advantages compared with the prior art. The following content describes them in conjunction with the data, charts and other information of the experimental process.

[0106] 1. Liquid leakage test of thermally adjustable rock wool board

[0107] Figure 2 These are photographs of liquid leakage experiments on rock wool / calcium chloride hexahydrate-based thermal insulation wall panels with different contents of calcium chloride hexahydrate-based phase change energy storage material. The results show that rock wool panels with 10wt.%–30wt.% calcium chloride hexahydrate-based phase change energy storage material exhibit good adsorption performance for thermal function regulation, and no crystal precipitation of calcium chloride hexahydrate-based phase change energy storage material occurs. However, when a modified solution containing 40wt.% calcium chloride hexahydrate-based phase change energy storage material is added, the adsorption capacity shows obvious saturation. Figure 2 As shown in (a), when the mass fraction of the calcium chloride hexahydrate-based phase change energy storage material is 40 wt.%, significant crystallization of the calcium chloride hexahydrate-based phase change energy storage material crystals occurred on the outer wall of the rock wool board, such as... Figure 2 As shown in (c), the adsorption capacity of rock wool reaches its maximum value when the mass fraction of the modified solution of calcium chloride hexahydrate-based phase change energy storage material is 30 wt.%. Figure 2(b) shows photographs of thermally modulated rock wool boards with different mass fractions of calcium chloride hexahydrate-based phase change energy storage material (PCE) in a liquid leakage test. The results show that even when the PCE content in the thermally modulated rock wool board reaches 40 wt.%, no leakage occurs. Careful observation reveals that the liquid remaining on the filter paper is PCE residue left from the brushing process on the fiber outer wall, rather than internal leakage. This phenomenon indicates the formation of a stable composite adhesion structure within the thermally modulated rock wool board. These two results demonstrate that thermally modulated rock wool boards containing 30 wt.% PCE can effectively achieve the maximum adsorption capacity of PCE and prevent leakage.

[0108] 2. Thermal performance of rock wool / calcium chloride hexahydrate based insulation wall panels

[0109] The specific heat capacity of rock wool board refers to the amount of heat absorbed (or released) by a unit mass of rock wool board when its temperature rises (or falls) by a unit amount. The higher the specific heat capacity, the stronger the heat absorption capacity of the rock wool board. The size of the specific heat capacity has a significant impact on regulating indoor temperature changes and daily life. When rock wool boards are used in building envelope structures, if their specific heat capacity is high, they can release or absorb more heat when the external ambient temperature rises or falls, thereby regulating indoor temperature changes to make them more suitable for human habitation and achieving the goal of saving energy consumption caused by cooling or heating. Figure 3 (a) shows the specific heat capacity of rock wool boards with different contents of calcium chloride hexahydrate-based phase change energy storage materials. The figure clearly shows that the specific heat capacity of the unmodified rock wool board is extremely low, at 0.0876 MJ / m³. 3 K, and the specific heat capacity of the modified rock wool board showed a gradual upward trend with the increase of the content of calcium chloride hexahydrate-based phase change energy storage material. The specific heat capacity of the thermal function-modifying rock wool board containing 10 wt.%, 20 wt.%, and 30 wt.% calcium chloride hexahydrate-based phase change energy storage material reached 0.3435 MJ / m. 3 K, 0.4793 MJ / m 3 K and 0.7001 MJ / m 3 K, compared to pure rock wool boards, increased by 292.1%, 447.1%, and 699.2%, respectively. This is because the addition of calcium chloride hexahydrate-based phase change energy storage material gives the rock wool board energy storage characteristics. When the external temperature rises (or falls), the phase change material in the rock wool board begins to absorb (or release) heat, which enables the rock wool board to be functionalized and applied more comprehensively and with more functions in building envelope structures.

[0110] Figure 3(b) shows the thermal conductivity of rock wool boards with different contents of calcium chloride hexahydrate-based phase change energy storage material. It can be seen that the thermal conductivity of the composite modified rock wool board increases with the increase of the calcium chloride hexahydrate-based phase change energy storage material content. This is partly because the addition of the calcium chloride hexahydrate-based phase change energy storage material increases the humidity or moisture content in the rock wool board, replacing the original air in the micropores. Air has a much lower thermal conductivity than liquid water, and the higher the humidity or moisture content, the higher the thermal conductivity. On the other hand, the addition of the calcium chloride hexahydrate-based phase change energy storage material fills the internal pores of the rock wool board. The thermal conductivity of solids is greater than that of liquids and much greater than that of air. During measurement, the increased temperature accelerates the thermal motion of molecules, promoting solid heat conduction and molecular convection heat transfer. Therefore, the thermal conductivity of the modified rock wool board increases. This phenomenon indicates that the addition of calcium chloride hexahydrate-based phase change energy storage material has both positive and negative effects on the thermal storage performance of the rock wool board.

[0111] The thermal diffusivity of rock wool board refers to its ability to maintain a uniform temperature when heated or cooled. The greater the thermal diffusivity of the rock wool board, the stronger its ability to pass through the rock wool board to the interior or exterior walls of the building. In other words, the stronger its ability to convert external heat into internal heat. Figure 3 (c) shows the thermal diffusivity of the rock wool board with different contents of calcium chloride hexahydrate-based phase change energy storage material. The test results show that the thermal diffusivity of the thermal function-regulating rock wool board gradually decreases with the increase of the content of calcium chloride hexahydrate-based phase change energy storage material. The reason for the decrease can be explained by formula (1):

[0112]

[0113] Where K represents thermal diffusivity; γ represents thermal conductivity; ρ represents density; and c represents specific heat capacity.

[0114] This formula shows that the factors affecting thermal conductivity also affect thermal diffusivity, as can be observed. Figure 3 (a) Figure 3 (b) and Figure 3(c) It can be seen that the increase in specific heat capacity of the modified rock wool board is much more rapid than the increase in thermal conductivity. Therefore, the thermal diffusivity of the modified rock wool board shows a decreasing trend, indicating that it has better thermal insulation capabilities. That is, for modified rock wool boards with low thermal diffusivity, in hot summers, when the ambient temperature rises sharply, it is less likely to rapidly transfer heat from the outside environment to the interior, thus preventing the indoor temperature from becoming too high or rising rapidly, thereby reducing energy consumption due to cooling. Similarly, in cold winters, when indoor heating reaches a comfortable temperature for the human body, indoor heat will not be rapidly transferred to the outside, thus saving energy consumption due to heating. The above description shows that although the calcium chloride hexahydrate-based phase change energy storage material increases the thermal conductivity of rock wool boards, it has a good effect on improving their overall thermal insulation capabilities.

[0115] 3. Energy storage and thermal insulation capacity of rock wool / calcium chloride hexahydrate-based insulation wall panels

[0116] The heat transfer performance of thermally regulated rock wool boards is mainly determined by their energy storage and insulation capacity, which varies with the content of calcium chloride hexahydrate-based phase change energy storage material in the rock wool board. The energy storage and insulation capacity of the thermally regulated rock wool boards was studied by measuring the temperature changes on the surface of the boards and at the center of the building interior. The test results are as follows: Figure 4 As shown; from Figure 4It can be observed that as the content of calcium chloride hexahydrate-based phase change energy storage material increases from 10 wt.% to 30 wt.%, the temperature changes on the surface and at the center of the room during the heating and cooling processes of the thermally regulating rock wool board gradually decrease. This trend is consistent with the thermal diffusivity of the thermally regulating rock wool board; the higher the content of calcium chloride hexahydrate-based phase change energy storage material, the smaller the indoor temperature change and the smaller the thermal diffusivity. Furthermore, by fitting and differentiating the surface heating curves of the rock wool board and the thermally regulating rock wool board, it was found that the curve slope decreases with increasing phase change material content. The curve slope for pure rock wool board is 0.0062, while the slopes for curves containing 10 wt.%, 20 wt.%, and 30 wt.% phase change material are 0.0052, 0.0043, and 0.0036, respectively. This means that the higher the phase change material content, the smaller the curve slope of the rock wool board. This trend further indicates that the higher the phase change material content, the slower the rock wool board heats up, the smoother the indoor temperature change, and the more significant the energy storage and insulation effect. When the content of calcium chloride hexahydrate-based phase change energy storage material is 30 wt.%, the highest surface temperature of the thermally modulated rock wool board and the highest internal temperature of the test chamber are 35.8℃ and 34.2℃, respectively. These are 2.5℃ and 3.4℃ lower than the highest surface temperature (38.3℃) and the highest internal temperature (37.6℃) of pure rock wool board, respectively. Furthermore, this result is lower than the highest temperature of the thermally modulated rock wool board with a lower content of calcium chloride hexahydrate-based phase change energy storage material. In other words, the higher the content of calcium chloride hexahydrate-based phase change energy storage material in the rock wool board, the stronger its energy storage and insulation capacity, and the smaller the temperature change inside the chamber. This is because the modification of the rock wool board with calcium chloride hexahydrate-based phase change energy storage material enhances its energy storage and insulation capacity. When the external environment begins to heat up, the phase change energy storage material begins to absorb more heat energy, preventing heat from rapidly transferring to the interior and thus maintaining a lower indoor temperature. Even at night, as the ambient temperature decreases, the phase change energy storage material releases the heat stored during the day, reducing indoor temperature fluctuations. In summary, compared to pure rock wool panels, thermally regulated rock wool panels offer better energy storage and insulation capabilities, more efficiently improve human thermal comfort, and achieve energy conservation and consumption reduction.

[0117] 4. Test results of compressive strength of thermally adjustable rock wool board

[0118] Figure 5 The diagram shows the compressive strength of a thermally modulated rock wool board. The compressive strength shown is the average of three sets of values. As can be seen, the compressive strength of the thermally modulated rock wool board increases proportionally with the increase of the calcium chloride hexahydrate-based phase change energy storage material content. This is because the phase change material itself has crystallization stress in its crystalline state, which connects the rock wool fibers. Figure 6As shown, without the addition of calcium chloride hexahydrate-based phase change energy storage material, the rock wool fibers are simply overlapped together. However, with the addition of calcium chloride hexahydrate-based phase change energy storage material, the fibers are bonded together, forming a strong mesh fiber structure, thereby improving the compressive strength of the rock wool board. When the addition amount of calcium chloride hexahydrate-based phase change energy storage material is 10 wt.%, 20 wt.%, and 30 wt.%, the compressive strength increases by 33.3%, 44.4%, and 55.5%, respectively. This demonstrates that the addition of calcium chloride hexahydrate-based phase change energy storage material has a significant effect on improving the compressive strength of the rock wool board.

[0119] 5. Microstructure of thermally adjustable rock wool board

[0120] Figure 6 (a)-(c) show rock wool boards ( Figure 6 (a) and thermally regulating rock wool board ( Figure 6 (b) and Figure 6 (c) The microstructure and structure under SEM clearly show that both the unmodified and modified rock wool exhibit slender fiber characteristics, indicating that the addition of calcium chloride hexahydrate-based phase change energy storage material did not disrupt the original fiber structure of the rock wool. Compared to the unmodified version, the unmodified rock wool fibers are slender and smooth, with larger gaps between the fibers. This provides ample space for the adhesion of the calcium chloride hexahydrate-based phase change energy storage material and lays a good foundation for improving the modification of the material. Figure 6 (b) and Figure 6 (c) It can be seen that the phase change material, calcium chloride hexahydrate-based phase change energy storage material, adheres more to the junctions of rock wool fibers, with the remainder adhering to the fiber tube walls and filling the fiber pores. Furthermore, from Figure 6 (b) and Figure 6 (c) It can be clearly seen that, due to the certain crystallization stress of the calcium chloride hexahydrate-based phase change energy storage material during condensation, it can bond the rock wool fibers together, thereby enhancing the mechanical strength of the rock wool board.

[0121] The present invention provides a thermally modulating rock wool board with energy storage and thermal insulation capabilities, comprising a rock wool / calcium chloride hexahydrate-based phase change energy storage material. The calcium chloride hexahydrate-based phase change energy storage material can store and release energy, while the rock wool serves as the carrier and support material for the phase change material, thus achieving a functional building insulation composite rock wool board with a combined thermal storage and thermal insulation effect. The following conclusions were drawn from the performance testing and characterization of the thermally modulating rock wool board:

[0122] (1) Through liquid leakage experiments, the maximum adsorption capacity of the rock wool board for calcium chloride hexahydrate-based phase change energy storage material was determined to be 30 wt.%. When the content of phase change material exceeds 30 wt.%, adsorption saturation is reached, and crystallization occurs on the outer wall of the rock wool fibers. SEM results show that the composite phase change material adheres to the rock wool fiber wall and fiber voids, forming a stable and highly resilient spatial grid structure, which enhances the mechanical strength of the rock wool board. The higher the mass percentage of calcium chloride hexahydrate-based phase change energy storage material, the higher the mechanical strength of the thermally modulated rock wool board.

[0123] (2) The higher the content of calcium chloride hexahydrate-based phase change energy storage material, the higher the specific heat capacity and the lower the thermal diffusivity of the thermally adjustable rock wool board. However, the drawback is that the thermal conductivity of the thermally adjustable rock wool board is higher. The above results indicate that the addition of calcium chloride hexahydrate-based phase change energy storage material has both positive and negative effects on the thermal performance of the rock wool board. However, the increase in the specific heat capacity and thermal density of the thermally adjustable rock wool board reduces the thermal diffusivity of the thermally adjustable rock wool board, and the overall thermal insulation performance is significantly enhanced.

[0124] (3) The test results of the building body show that with the increase of calcium chloride hexahydrate-based phase change energy storage materials, the energy storage and heat insulation capacity of rock wool boards is enhanced, the temperature fluctuation at the center of the building body is smaller, and the rate of temperature rise and fall at the center of the building body becomes more gradual, which is conducive to energy conservation and consumption reduction of buildings.

[0125] 6. Orthogonal Experiment of Calcium Chloride Hexahydrate-Based Phase Change Energy Storage Material

[0126] (1) Orthogonal experimental design of calcium chloride hexahydrate-based phase change energy storage material

[0127] The experiment used the supercooling and phase change temperature of calcium chloride hexahydrate-based phase change energy storage materials as indicators, and the contents of magnesium chloride hexahydrate, strontium chloride hexahydrate, and carboxymethyl cellulose as the three factor variables. Each factor was designed with three levels. Table 6.1 is the orthogonal experimental factor level table. Based on literature review, the mass percentages of A (MgCl2·6H2O) were set to 10wt.%, 20wt.%, and 30wt.%, the mass percentages of B (SrCl2·6H2O) were set to 1wt.%, 2wt.%, and 3wt.%, and the mass percentages of C (CMC) were set to 0.5wt.%, 1wt.%, and 1.5wt.%. To avoid human error and obtain more accurate and scientific experimental results, the levels of each factor were randomly arranged.

[0128] Table 6.1 Factor levels table of orthogonal experiment

[0129] level <![CDATA[A(MgCl2·6H2O)]]> <![CDATA[B(SrCl2·6H2O)]]> C(CMC) 1 20wt.% 1 wt.% 1.5 wt.% 2 10wt.% 2wt.% 1.0 wt.% 3 30wt.% 3wt.% 0.5 wt.%

[0130] After determining the factor level variables, according to the orthogonal experimental table L9(3) 4 The experimental scheme shown in Table 6.2 was designed. Then, the calcium chloride hexahydrate-based phase change energy storage material was subjected to heating and cooling tests. The calcium chloride hexahydrate-based phase change energy storage material was heated to 50°C in a water bath to completely dissolve it. Then, during its cooling and solidification process, a temperature data logger was used to record the temperature change over time in order to measure its supercooling and phase change temperature.

[0131] Table 6.2 Orthogonal experimental scheme for calcium chloride hexahydrate-based phase change energy storage materials

[0132] Table 6.2Orthogonal experimental scheme of Calcium chloridehexahydrate-based

[0133] phase change material

[0134]

[0135] (2) Testing and characterization of calcium chloride hexahydrate-based phase change energy storage materials based on orthogonal experimental results

[0136] First, the calcium chloride hexahydrate-based phase change energy storage material (PCE) based on orthogonal experimental results was heated to 50°C and then naturally cooled. Temperature changes were recorded using thermocouples to determine the supercooling and phase transition temperature, while observing whether phase separation occurred. The latent heat of phase transition of 20±5 mg of the calcium chloride hexahydrate-based PCE was tested using TGA / DSC under a pure nitrogen atmosphere, a heating rate of 10 K / min, and a temperature range of 0-200°C. Phase analysis of the PCE after multiple cycles was performed using an X-ray diffractometer (D / MAX2500PC). XRD was used to characterize the PCE within a 2θ range of 10°–50° at a scan rate of 10° / min. Thermogravimetric analysis (TG) was used to characterize the thermogravimetric changes of the PCE within the temperature range of 25-400°C under a nitrogen atmosphere and a heating rate of 10 K / min.

[0137] (3) Properties of calcium chloride hexahydrate

[0138] The experimental results indicate that supercooling is an inherent defect of phase change hydrated salt materials. The presence of supercooling will severely inhibit and dissipate the latent heat released during the cooling and crystallization of calcium chloride hexahydrate. Figure 7The curve shows the cooling crystallization curve of calcium chloride hexahydrate. The curve clearly shows that the phase transition temperature of calcium chloride hexahydrate is 28.4℃ and the supercooling is 10.1℃. This result shows that a lot of heat energy is ineffectively consumed during its exothermic process. Figure 8 The image shown is a digital photograph of calcium chloride hexahydrate crystallization after 10 thermal cycles. The photograph clearly shows severe phase separation in the calcium chloride hexahydrate, resulting in the formation of insoluble substances at the bottom layer. Observation revealed that these insoluble substances remained unchanged during the dissolution and cooling processes of the calcium chloride hexahydrate phase transition. In other words, these insoluble substances did not participate in the energy storage and release process at all, causing most of the latent heat to be lost due to the phase separation defect. This indicates that pure calcium chloride hexahydrate cannot sustainably and stably perform its energy storage function when used alone, and improvements are needed to reduce its supercooling, control the phase transition temperature, and eliminate phase separation defects.

[0139] (4) Results of orthogonal experiments

[0140] The effective application of orthogonal experiments can improve work efficiency and reduce workload. The subcooling degree was selected as the evaluation index for the orthogonal experimental data analysis of the heating and cooling tests of calcium chloride hexahydrate-based phase change energy storage materials.

[0141] Figure 9 These are the cooling curves of the S-1, S-2, S-3, and S-4 modified samples. Figure 10 These are the cooling curves of the modified samples S-5, S-6, S-7, S-8, and S-9. From these cooling curves, we can clearly see that due to the addition of magnesium chloride hexahydrate, the modified calcium chloride hexahydrate-based phase change energy storage material, obtained through orthogonal experimental design, forms a binary eutectic mixed salt, leading to a decrease in phase change temperature. The supercooling is also significantly reduced due to the addition of the nucleating agent strontium chloride hexahydrate. Furthermore, the effective exothermic time plateau is extended from 69 min for pure calcium chloride hexahydrate to approximately 83.2 min for the modified sample, indicating a significant increase in exothermic time.

[0142] Will Figure 9-10 The supercooling and phase transition temperature data obtained from the cooling experiment were input into orthogonal experiment tables 6.3 and 6.4 for orthogonal experiment result analysis.

[0143] Table 6.3 is an intuitive analysis table of orthogonal experiments obtained using supercooling as the evaluation index. K1, K2, and K3 represent the arithmetic mean of the supercooling results obtained at levels 1, 2, and 3 for each factor in their respective columns, and R represents the range. Analysis of the average supercooling values ​​of the calcium chloride hexahydrate-based phase change energy storage material samples in Table 6.3 shows that, for the factor magnesium chloride hexahydrate, the calcium chloride hexahydrate-based phase change energy storage material has the smallest average supercooling value of 1.000℃ when the mass fraction of magnesium chloride hexahydrate is 10 wt.%. For the three levels of strontium chloride hexahydrate, the average supercooling value of the calcium chloride hexahydrate-based phase change energy storage material reaches its minimum value of 1.400℃ when its doping amount is 2 wt.%. When the addition amount of carboxymethyl cellulose is 1 wt.%, the average supercooling value of the calcium chloride hexahydrate-based phase change energy storage material sample is the smallest, also 1.400℃. After analyzing the optimal levels of the three factors affecting the supercooling of the composite salt, and combining the range data analysis of the orthogonal experiment, the optimal combination with supercooling as the evaluation index can be obtained as: A2B2C2, that is, the mass fraction of magnesium chloride hexahydrate is 10 wt.%, the mass fraction of strontium chloride hexahydrate is 2 wt.%, and the mass fraction of carboxymethyl cellulose is 1 wt.%.

[0144] Table 6.3 Visual Analysis of Orthogonal Experiment Results Based on Subcooling

[0145] Table 6.3Intuitive analysis table of orthogonal experimental results with supercooling

[0146] degree

[0147]

[0148]

[0149] Figure 11This is a trend graph of the average supercooling value of calcium chloride hexahydrate-based phase change energy storage materials at the same level. The graph clearly shows that the average supercooling value changes drastically with the changes in the levels of the three factors, indicating that all three factors have a significant impact on supercooling and are considered major influencing factors. Experimental results show that magnesium chloride hexahydrate can reduce the supercooling value of the phase change material because it forms a eutectic hydrate salt with calcium chloride hexahydrate, resulting in a more compact crystal structure. Magnesium chloride hexahydrate not only regulates the phase change temperature but also acts as a nucleating agent. Strontium chloride hexahydrate can reduce supercooling because it has the same crystal structure as calcium chloride hexahydrate and a much higher melting point, thus providing crystallization sites for the growth of calcium chloride hexahydrate crystals. This allows calcium chloride hexahydrate to grow and crystallize along the crystal planes of strontium chloride hexahydrate, successfully overcoming the most difficult initial nucleation stage. For carboxymethyl cellulose, the supercooling trend graph shows that the supercooling decreased significantly when its dosage increased from 0.5 wt.% to 1 wt.%, while the supercooling did not change significantly when its dosage increased from 1 wt.% to 1.5 wt.%. It can be inferred that the reason why carboxymethyl cellulose reduces supercooling is that it increases the viscosity of calcium chloride hexahydrate-based phase change energy storage material, forming flocs with a certain viscosity in the solution. When the dosage reaches 1.0 wt.%, the supercooling no longer changes significantly, which means that the best effect of reducing supercooling is achieved.

[0150] The phase transition temperature was selected as the evaluation index for the orthogonal experimental data analysis of the heating and cooling tests of calcium chloride hexahydrate-based phase change energy storage materials.

[0151] Table 6.4 shows the results of orthogonal experiments using the phase transition temperature of calcium chloride hexahydrate-based phase change energy storage materials as the evaluation index. By comparing the average values ​​of the phase transition temperature of each influencing factor in Table 6.4, it can be seen that when the content of magnesium chloride hexahydrate is 10 wt.%, the phase transition temperature of the calcium chloride hexahydrate-based phase change energy storage material is the lowest at 24.5℃. For the three levels of strontium chloride hexahydrate, when its content is 3.0 wt.%, the phase transition temperature of the calcium chloride hexahydrate-based phase change energy storage material reaches the minimum value of 24.6℃. Finally, when the content of carboxymethyl cellulose is 1.0 wt.%, the phase transition temperature of the calcium chloride hexahydrate-based phase change energy storage material is the lowest, at 24.7℃. To obtain the experimental range data for calcium chloride hexahydrate and to analyze the optimal levels of the three factors affecting the phase transition temperature of the phase change material, the optimal combination with phase transition temperature as the evaluation index can be obtained as: A2B3C2, that is, the content of magnesium chloride hexahydrate is 10 wt.%, the content of strontium chloride hexahydrate is 3 wt.%, and the content of carboxymethyl cellulose is 1.0 wt.%.

[0152] Table 6.4 Visual Analysis of Orthogonal Experiment Results Based on Phase Transition Temperature

[0153] Table 6.4Intuitive analysis table based on phase transitiontemperature as the result of

[0154] orthogonal experiment

[0155]

[0156] To visually demonstrate the influence of the three factors on the phase change temperature results, a factor level trend graph was plotted, with the factor level value on the x-axis and the average phase change temperature at the same level on the y-axis. The factor level trend graph allows for a direct observation of the magnitude of each factor's influence on the phase change energy storage material. Figure 12 As can be seen, the order of influence of the three factors on the phase transition temperature of the sample is: magnesium chloride hexahydrate > strontium chloride hexahydrate > carboxymethyl cellulose. The change in the content of magnesium chloride hexahydrate has the greatest impact on the phase transition temperature of the sample and is the most important influencing factor. The main influencing factor, magnesium chloride hexahydrate, reduces the phase transition temperature of calcium chloride hexahydrate phase transition material by forming a eutectic salt with calcium chloride hexahydrate, thus acting as a phase transition temperature regulator. Figure 12 The graph shows the phase transition temperature trend at the same level. It can be observed that the phase transition temperature of the sample varies significantly with changes in the levels of magnesium chloride hexahydrate and strontium chloride hexahydrate. This indicates that the phase transition temperature of the phase change material is highly sensitive to changes in the values ​​of magnesium chloride hexahydrate and strontium chloride hexahydrate, significantly affecting the experimental results; these are considered key influencing factors. Conversely, changes in the level of carboxymethyl cellulose have little effect on the phase transition temperature, making it a secondary influencing factor.

[0157] The optimal formulation of the calcium chloride hexahydrate-based phase change energy storage material, obtained from orthogonal experimental data analysis using supercooling as the evaluation index, is A2B2C2. The optimal formulation using phase change temperature as the evaluation index is also A2B2C2. At level B2, the average phase change temperature of the composite material is 24.9℃, which is within the range of human comfort. However, level B3 represents the level with the highest average supercooling of the composite material. At this level, the calcium chloride hexahydrate-based phase change energy storage material will lose a significant amount of heat energy during heat release. Therefore, to maximize the modification effect of the composite material, the final formulation of the calcium chloride hexahydrate-based phase change energy storage material is determined to be: 9–11 wt.% magnesium chloride hexahydrate; 1.8–2.2 wt.% strontium chloride hexahydrate; 0.8–1.2 wt.% carboxymethyl cellulose; and the remainder being calcium chloride hexahydrate. The preferred formulation is A2B2C2. That is, the mass fraction of magnesium chloride hexahydrate is 10 wt.%, the mass fraction of strontium chloride hexahydrate is 2 wt.%, and the mass fraction of carboxymethyl cellulose is 1 wt.%.

[0158] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a rock wool / calcium chloride hexahydrate-based thermal insulation wall panel, characterized in that, By combining calcium chloride hexahydrate-based phase change energy storage material with rock wool board, a thermally regulating rock wool board is formed. By optimizing the composition and preparation process of the phase change energy storage material, and by using silane coupling agent to enhance the material bonding, the high thermal insulation performance and thermal regulation capability of the thermal insulation wall panel are achieved, resulting in a new type of high-efficiency thermal insulation material. The method for preparing the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel involves coupling a rock wool board and a phase change energy storage material to prepare a thermally regulated rock wool board. The rock wool board uses calcium chloride hexahydrate-based phase change energy storage material, with calcium chloride hexahydrate as the main phase change material, and 10 wt.% magnesium chloride hexahydrate, 2 wt.% strontium chloride hexahydrate, and 1 wt.% carboxymethyl cellulose added to it. The rock wool board serves as the carrier for the phase change energy storage material. Modified solutions were prepared by adding 8–12 wt.% hexahydrate calcium chloride-based phase change energy storage material, 18–22 wt.% and 28–32 wt.% relative to the mass fraction of anhydrous ethanol, to anhydrous ethanol, respectively. After adding silane coupling agent KH500 to the modified solution, it is brushed onto the surface of the rock wool board. The brushing is stopped when the penetration depth of the modified solution reaches 20mm.

2. The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel as described in claim 1, characterized in that, The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel energy storage material further includes: Calcium chloride hexahydrate was heated to 50°C in a water bath, and then magnesium chloride hexahydrate, strontium chloride hexahydrate, and carboxymethyl cellulose were added to prepare calcium chloride hexahydrate-based phase change energy storage materials.

3. The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel as described in claim 1, characterized in that, The preparation method of calcium chloride hexahydrate-based phase change energy storage material is as follows: Calcium chloride hexahydrate is heated to 50°C and completely melted in a container, then the following materials are added; Add 9–11 wt.% magnesium chloride hexahydrate; Add 1.8–2.2 wt.% strontium chloride hexahydrate; Add 0.8–1.2 wt.% carboxymethyl cellulose; Mix thoroughly.

4. The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel as described in claim 1, characterized in that, After adding silane coupling agent KH500 to the modified solution, it is brushed onto the surface of the rock wool board. The brushing is stopped when the penetration depth of the modified solution reaches 20mm. The coated rock wool board was placed in a fume hood for 24 hours to evaporate at room temperature, and then placed in a 40℃ forced-air drying oven for 24 hours to dry completely, thus preparing a thermally functional rock wool board composed of rock wool / calcium chloride hexahydrate-based phase change material.

5. The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel as described in claim 1, characterized in that, The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel further includes: The maximum adsorption capacity of the thermally adjustable rock wool board for phase change material was determined by a liquid leakage test. The thermal conductivity of the heat-regulating rock wool board was measured using the double-plate protective heat plate balance method, and the specific heat capacity and thermal diffusivity were measured using the thermal constant analyzer method. The energy storage and insulation capacity of the thermally regulating rock wool board was tested using the room structure and thermocouples. The compressive strength of the heat-regulating rock wool board was determined using a universal testing machine. The microstructure of the thermally adjustable rock wool board was characterized by morphology analysis.

6. The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel as described in claim 5, characterized in that, The specific process for testing the thermally regulating rock wool board using the chamber body and thermocouples is as follows: First, adjust the room temperature to 20°C, then turn on the simulated heat source above the chamber and heat for 2 hours to ensure that the calcium chloride hexahydrate-based phase change energy storage material in the rock wool board reaches or exceeds the phase change temperature; finally, turn off the simulated heat source and test the curve of the chamber automatically cooling to room temperature. During cooling, the temperature change is also recorded by a temperature recorder.

7. The preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel as described in claim 5, characterized in that, The specific process of characterizing the microstructure of the thermally adjustable rock wool board through morphology analysis is as follows: After the thermally adjustable rock wool board was subjected to gold sputtering in a vacuum environment, its microstructure and surface morphology were observed at room temperature using a JEOL JSM-6701F field emission scanning electron microscope with an accelerating voltage of 20kV.

8. A rock wool / calcium chloride hexahydrate-based thermal insulation wall panel prepared by the preparation method of the rock wool / calcium chloride hexahydrate-based thermal insulation wall panel according to any one of claims 1-7.

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