A phase change temperature regulating wall and a preparation method thereof

Abstract

The application provides a phase change temperature regulating wall and a preparation method, relates to the field of phase change materials, and aims at the problem that the heat preservation layer of the phase change material still needs to be combined with the existing building structure, leading to complex construction. The expanded perlite absorbs paraffin, and the pore channel of the expanded perlite is blocked by using cementing material, so that the problem of easy leakage of the phase change lightweight aggregate is solved. The prepared small-particle-size phase change lightweight aggregate can be used to prepare phase change concrete, can be directly used as a structural layer, has good heat storage and heat preservation performance, and is combined with a crack prevention layer, a steel mesh connecting layer, a foam heat preservation layer and the like to form a wallboard. Then, the phase change temperature regulating wall is obtained by using wallboard combination construction, and the construction efficiency requirement of prefabricated modular construction is met.

Description

Technical Field

[0001] This invention relates to the field of phase change materials, specifically to a phase change temperature regulating wall and its preparation method. Background Technology

[0002] Currently, there are two main approaches to applying phase change materials (PCMs) in building insulation. One approach involves using porous metals or lightweight porous materials as carriers to absorb and adsorb PCMs, forming composite PCMs which are then directly used as raw materials for PCM insulation wall materials. However, this method often significantly impacts the performance of building materials. Directly introducing porous lightweight materials reduces the mechanical properties of the building materials, while the large-scale introduction of porous metals can cause severe thermal bridging. Therefore, this approach mostly limits the use of PCM insulation wall materials as an additional insulation layer, increasing the overall construction complexity of the exterior walls. Furthermore, this method cannot effectively prevent PCM leakage. The second approach involves using PCM microcapsules in building materials. Compared to the first method, this has less impact on strength and allows for direct purchase and application, eliminating the need for composite PCM preparation and simplifying the construction process. However, this method is more expensive and difficult to promote on a large scale.

[0003] Existing technologies provide several methods for preparing phase change lightweight aggregates and applying these aggregates to thermal insulation building materials. These aggregates possess phase change heat storage capabilities, high strength, and leak-proof properties. The provided phase change thermal insulation building materials for thermal bridges are suitable for on-site casting in thermal bridge environments, effectively eliminating thermal bridging and improving building thermal comfort. However, they are still used as insulation layers. These thermal bridge thermal insulation building materials are applied to the exterior of the building structure and require on-site casting, making construction complex and extending the project construction period. This makes it difficult to meet the current demand for rapid prefabricated modular construction. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a phase change thermal regulating wall and its preparation method. Expanded perlite is used to absorb paraffin wax, and then a cementing material is used to seal the pores of the expanded perlite to prepare phase change lightweight aggregate with a particle size of 2.35mm-5mm. This is achieved through multiple optimizations: improving concrete density through gradation optimization, enhancing leak-proof performance through specific surface area advantage, and adapting flowability to prefabrication processes. This solves the problem of leakage in phase change lightweight aggregate, achieving a functional leap from an auxiliary insulation material to a main structural material. The resulting small-particle-size phase change lightweight aggregate can be used to prepare phase change concrete. The phase change concrete also uses sulfoaluminate cementing material, providing aggregate strength, efficient encapsulation, and preventing leakage of the phase change material through a crystal-colloid composite system. This allows the phase change concrete to be directly used as a structural layer such as a phase change thermal insulation wall, exhibiting excellent heat storage and insulation performance. Combined with a crack-resistant layer, steel mesh connection layer, and foam insulation layer, wall panels are formed. The phase change thermal regulating wall is then constructed using these wall panels, meeting the construction efficiency requirements of prefabricated modular construction.

[0005] The first objective of this invention is to provide a phase change temperature regulating wall, which adopts the following solution:

[0006] This includes phase change concrete, which is composed of the following components in parts by mass:

[0007] 30-50 parts of phase change lightweight aggregate, 20-30 parts of gravel, 15-20 parts of sulfoaluminate cementitious material, and 10-20 parts of water;

[0008] The phase change lightweight aggregate is prepared by combining expanded perlite with phase change material paraffin, and the particle size of the phase change lightweight aggregate is 2.35mm-5mm.

[0009] The sulfoaluminate cementitious material comprises: 40-50 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 5-10 parts of desulfurized building gypsum, 20-35 parts of mineral powder, and 0.1-0.5 parts of water-reducing agent.

[0010] Furthermore, the method for preparing the phase change lightweight aggregate includes:

[0011] Expanded perlite adsorbs paraffin wax, a phase change material, to obtain a composite phase change material.

[0012] The composite phase change material and the cementitious material are mixed and granulated to obtain phase change lightweight aggregate with a particle size of 2.35mm-5mm.

[0013] Furthermore, the expanded perlite adsorbs the phase change material paraffin, comprising:

[0014] Mix 25-33.3 parts by weight of expanded perlite with 66.7-75 parts by weight of paraffin wax and impregnate.

[0015] Furthermore, vacuum impregnate for 3-8 hours under negative pressure and at 40℃-60℃.

[0016] Furthermore, the expanded perlite has a particle size of 1.18mm-2.35mm, and the cementing material is a sulfoaluminate cementing material.

[0017] Further, the granulation includes:

[0018] Composite phase change materials with a particle size distribution of 1.18mm-2.35mm are sieved and added to a granulator;

[0019] Phase change lightweight aggregate is obtained by granulation.

[0020] Furthermore, when adding the composite phase change material to the granulator, 20%-30% of the composite phase change material's mass of water is added for pre-wetting.

[0021] Furthermore, the phase change concrete, combined with the crack-resistant layer, the steel mesh connecting layer, and the foam insulation layer, forms a wall panel.

[0022] A second objective of this invention is to provide a method for preparing a phase change temperature-regulating wall, comprising the following steps:

[0023] Soak the phase change lightweight aggregate, remove it after it becomes saturated with water and drain it to obtain pre-wetted phase change lightweight aggregate;

[0024] Sulfoaluminate cement, ordinary silicate cement, desulfurized building gypsum, mineral powder, and water-reducing agent are mixed in a certain proportion to obtain a mixed powder.

[0025] After mixing the powder with water, stir to form a slurry. Add stones and pre-wetted phase change lightweight aggregate to the slurry, continue stirring until evenly mixed, and then pour into molds.

[0026] After initial setting, a crack-resistant layer, a steel mesh connecting layer, and a foam insulation layer are filled to form a wall panel. The combination of these wall panels creates a phase change temperature regulating wall.

[0027] Furthermore, the prepared phase change lightweight aggregate was soaked in water for 2 hours, the mixed powder was mixed with water and stirred for 2-3 minutes, and the slurry was mixed with gravel and pre-wetted phase change lightweight aggregate and stirred for another 2-3 minutes.

[0028] Compared with the prior art, the advantages and positive effects of this invention are:

[0029] To address the issue of complex construction caused by the need to integrate insulation layers made from current phase change materials with existing building structures, expanded perlite is used to absorb paraffin wax, and then cementing materials are used to seal the pores of the expanded perlite. This solves the problem of leakage that easily occurs with phase change lightweight aggregates. The resulting small-particle-size phase change lightweight aggregate can be used to prepare phase change concrete, which can be used directly as a structural layer. It has good heat storage and insulation performance. Combined with crack-resistant layers, steel mesh connection layers, and foam insulation layers, it forms wall panels. Then, the phase change temperature-regulating wall is constructed by combining the wall panels, which meets the construction efficiency requirements of prefabricated modular construction.

[0030] Phase change concrete was prepared using 2.35mm-5mm phase change lightweight aggregate, and then a phase change temperature-regulating wall was formed. The resulting specimens showed a 28-day compressive strength of up to 48MPa, a flexural strength of 8MPa, and an overall density of 1432kg / m³. It can be used directly as an exterior wall structural layer. Compared with the existing technology of phase change insulation building materials for thermal bridges, which have a 28-day compressive strength of over 5MPa, the phase change lightweight aggregate in this invention shows more outstanding performance in terms of optimized mechanical properties, and can better meet the load-bearing requirements of the exterior wall as a structural layer.

[0031] The particle size of phase change lightweight aggregate is limited to 2.35mm-5mm. It is a systematic design based on the function of the structural layer. It improves the density of concrete through gradation optimization, enhances the anti-leakage performance through the specific surface area advantage, and optimizes the flowability to adapt to the prefabrication process from multiple angles. This enables phase change lightweight aggregate to meet the needs of the main structural material, and ultimately achieves a functional leap from thermal insulation auxiliary material to main structural material.

[0032] The sulfoaluminate cementitious material uses a composite formula of 40-50 parts sulfoaluminate cement and 10-20 parts ordinary silicate cement. Through the synergistic effect of the two cements, it retains the characteristics of rapid hardening and early strength of sulfoaluminate cement, while optimizing the later strength stability through ordinary silicate cement, and at the same time reducing the risk of leakage of phase change materials.

[0033] Sulfoaluminate cement is a solid waste-based sulfoaluminate cement that forms a composite system with silicate cement and by-product desulfurized building gypsum and mineral powder. It encapsulates phase change lightweight aggregate, acting as an aggregate shell. The abundant needle-like and rod-shaped ettringite produced during the hydration of sulfoaluminate cement forms a robust framework structure, providing excellent mechanical properties; while the hydrated calcium silicate colloid formed during the hydration of ordinary silicate cement fills the pores of the framework, making the structure more compact. This crystal-colloid composite system provides aggregate strength and efficient encapsulation, preventing leakage of phase change materials—a dual function. The addition of by-product desulfurized building gypsum and mineral powder, while consuming accumulated solid waste and improving environmental benefits, also works synergistically to further enhance early strength and rapid setting characteristics, improve construction and production efficiency, and shorten the production cycle. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0035] Figure 1 This is a schematic flowchart of the phase change lightweight aggregate preparation method in Embodiment 1 of the present invention.

[0036] Figure 2 This is a SEM image of the aggregate shell formed by the sulfoaluminate cementitious material in Example 1 of the present invention. Figure 2 (a) is a SEM image of the aggregate shell formed by the sulfoaluminate cementitious material in Example 1 of the present invention. Figure 2 (b) is a SEM image of another region of the aggregate shell formed by the sulfoaluminate cementitious material in Example 1 of the present invention.

[0037] Figure 3 This is a schematic diagram of the microstructure of expanded perlite and cementing material in Embodiment 1 of the present invention. Figure 3 (a) is a schematic diagram of the microstructure of the expanded perlite and cementing material forming the outer shell of the aggregate core in Embodiment 1 of the present invention. Figure 3 (b) is a schematic diagram of the microstructure of another region of the outer shell formed by the expanded perlite and cementing material in the aggregate core of Embodiment 1 of the present invention. Figure 3 (c) is a spectral scan result of the expanded perlite and cementing material forming the outer shell of the aggregate core in Example 1 of the present invention. Detailed Implementation

[0038] Unless otherwise specified, the components used in the following examples and comparative examples are all commercially available products. The water-reducing agent is a polycarboxylate water-reducing agent, and the expanded perlite has a particle size of 1.18mm-2.35mm and a bulk density of 65kg / m³. .

[0039] Example 1

[0040] A phase change temperature regulating wall includes phase change concrete, which is composed of the following components in parts by mass:

[0041] 30-50 parts of phase change lightweight aggregate, 20-30 parts of gravel, 15-20 parts of sulfoaluminate cementitious material, and 10-20 parts of water;

[0042] The phase change lightweight aggregate is prepared by combining expanded perlite with phase change material paraffin, and the particle size of the phase change lightweight aggregate is 2.35mm-5mm.

[0043] The sulfoaluminate cementitious material comprises: 40-50 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 5-10 parts of desulfurized building gypsum, 20-35 parts of mineral powder, and 0.1-0.5 parts of water-reducing agent.

[0044] like Figure 1 As shown, a method for preparing phase change lightweight aggregate is presented.

[0045] The method for preparing phase change lightweight aggregate includes the following steps:

[0046] 1) Sift expanded perlite with a particle size distribution of 1.18mm-2.35mm, mix 25-33.3 parts by weight of expanded perlite with 66.7-75 parts by weight of paraffin wax, and place the mixture in a vacuum oven at a vacuum degree of 10. -4 Composite phase change materials were prepared by vacuum impregnation at 40℃-60℃ for 3-8 hours.

[0047] 2) Screen out composite phase change materials with a particle size distribution of 1.18mm-2.35mm, add them into the granulator in proportion, and add water at 20%-30% of the mass of the composite phase change materials for pre-wetting;

[0048] 3) Add sulfoaluminate cementitious material and water in proportion to form phase change lightweight aggregate with a particle size distribution of 2.35mm-5mm.

[0049] Tests showed that leakage of phase change lightweight aggregate was less than 0.5%.

[0050] In step 1), expanded perlite is added to a mixer, liquid paraffin is poured in, and the mixture is slowly stirred at 140 r / min for 40 s to achieve uniform mixing.

[0051] Expanded perlite and paraffin wax were mixed at a mass ratio of 1:2 to prepare a composite phase change material. The bulk density of the composite phase change material was measured to be 217.8 kg / m³. Water absorption rate 113.3%, latent heat of phase change 122 J / g; bulk density of 1:3 composite phase change material 307 kg / g. Water absorption rate 44%, latent heat of phase change 143J / g.

[0052] In step 2), composite phase change materials with different particle sizes will affect the granulation effect. When there are a large number of fine powders smaller than 1.18 mm in the composite phase change material, the powder will agglomerate and form large pieces during the granulation process, affecting the uniformity of the aggregate and the coating effect of the cementitious material. Therefore, composite phase change materials with similar particle sizes and the same gradation are selected for preparation.

[0053] The primary objective of this embodiment is to prepare fine aggregates with a particle size of less than 5 mm; therefore, a composite phase change material with a particle size of 1.18 mm to 2.35 mm is selected. In other alternative embodiments, if the goal is to prepare coarse aggregates with a particle size distribution greater than 5 mm, expanded perlite with a particle size greater than 5 mm can be used to prepare a composite phase change material with a particle size greater than 5 mm, and then a lightweight phase change aggregate can be prepared.

[0054] In this embodiment, limiting the particle size of the phase change lightweight aggregate to 2.35mm-5mm is a core feature for achieving the structural layer function. When phase change lightweight aggregate is applied to phase change concrete, the small-sized aggregate can be more evenly dispersed in the concrete, forming a dense structure with gravel and cementitious materials. This results in higher compressive strength of the phase change concrete after curing, allowing it to be directly used as an exterior wall structural layer.

[0055] In addition, the selection of 2.35mm-5mm phase change lightweight aggregates forms a complementary gradation with the coarse aggregates used in the preparation of phase change concrete. The small-sized aggregates can fill the gaps between coarse aggregates such as stones, and through the bonding effect of cementitious materials, the internal pores of the concrete are reduced, forming a dense structure with coarse aggregate skeleton, fine aggregate filling and cementitious material bonding. The gradation design is one of the core reasons for ensuring the high compressive strength of phase change concrete.

[0056] It should be noted that using phase change lightweight aggregates with a diameter of 2.35mm-5mm results in a larger specific surface area and more thorough contact with the cementitious material. The cementitious material can evenly coat the surface of the phase change lightweight aggregate and penetrate to the edge of the pores, forming a dense sealed shell.

[0057] The use of 2.35mm-5mm phase change lightweight aggregate ensures good compatibility with subsequent construction processes of the prepared phase change concrete and is suitable for prefabricated modular structural layers. The 2.35mm-5mm phase change lightweight aggregate has better fluidity, allowing for uniform filling of the mold during prefabricated wall panel pouring, avoiding incomplete compaction or air bubble residue caused by excessively large particles. Simultaneously, the uniform particle size ensures consistent performance across all parts of the wall panel, guaranteeing balanced stress distribution across the assembled phase change temperature-regulating wall.

[0058] In step 3), the leakage is detected by wrapping the phase change lightweight aggregate with filter paper, baking it in a 45-degree Celsius high-temperature oven for 24 hours, weighing the change in mass of the filter paper to determine the amount of paraffin that seeps out of the aggregate, and then calculating it.

[0059] Phase change lightweight aggregate was prepared by using a ratio of 17 parts by weight of composite phase change material, 65 parts by weight of sulfoaluminate cementitious material, and 18 parts by weight of water. The leakage rate of the resulting phase change lightweight aggregate was only 0.36%.

[0060] Composite phase change materials have a latent heat of phase change of 100J / g-160J / g and excellent heat storage performance. The resulting phase change lightweight aggregate has a latent heat of phase change of 20J / g-30J / g.

[0061] The phase change lightweight aggregate is prepared using the phase change lightweight aggregate preparation method described above.

[0062] In this embodiment, the obtained lightweight aggregate consists of the following components in parts by weight: 15 parts of composite phase change material, 70 parts of sulfoaluminate cementitious material, and 15 parts of water. Testing showed that the leakage rate of the obtained phase change lightweight aggregate was only 0.1%; the bulk density was 960 kg / m³. The compressive strength of the cylinder can reach 8.3 MPa after 28 days.

[0063] A phase change temperature regulating wall, utilizing the phase change lightweight aggregate prepared as described above.

[0064] A phase change temperature regulating wall, using phase change concrete, wherein the phase change concrete is composed of the following components in parts by mass:

[0065] Use 30-50 parts of phase change lightweight aggregate prepared as in Example 1, 20-30 parts of gravel, 15-20 parts of sulfoaluminate cementitious material, and 10-20 parts of water.

[0066] The sulfoaluminate cementitious materials include: 40-50 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 5-10 parts of desulfurized building gypsum, 20-35 parts of mineral powder, and 0.1-0.5 parts of water-reducing agent.

[0067] In addition, phase change concrete, together with crack-resistant layer, steel mesh connection layer and foam insulation layer, forms wall panels. Through the construction of wall panel combination, phase change temperature regulating wall is obtained, which can cause the internal phase change lightweight aggregate to undergo phase change under the action of solar energy to resist temperature changes.

[0068] The preparation method of the phase change temperature regulating wall includes the following steps:

[0069] Soak the phase change lightweight aggregate, remove it after it becomes saturated with water and drain it to obtain pre-wetted phase change lightweight aggregate;

[0070] Sulfoaluminate cement, ordinary silicate cement, desulfurized building gypsum, mineral powder, and water-reducing agent are mixed in a certain proportion to obtain a mixed powder.

[0071] After mixing the powder with water, stir to form a slurry. Add stones and pre-wetted phase change lightweight aggregate to the slurry, continue stirring until evenly mixed, and then pour into molds.

[0072] After initial setting, a crack-resistant layer, a steel mesh connecting layer, and a foam insulation layer are filled to form a wall panel. The combination of these wall panels creates a phase change temperature regulating wall.

[0073] Specifically, including:

[0074] 1) Soak the prepared phase change lightweight aggregate in water for 2 hours to make it saturated with water, then remove it and drain the surface water for later use.

[0075] 2) Mix all the powders in the above formula except for phase change lightweight aggregate and gravel evenly, and add them to the mixer;

[0076] 3) Add water and stir for 2-3 minutes to form a slurry;

[0077] 4) Add the gravel and pre-wetted phase change lightweight aggregate, continue stirring for 2-3 minutes, then pour into molds;

[0078] 5) After initial setting, fill with crack-resistant layer, steel mesh connection layer, foam insulation layer, etc. to form wall panel for use as a phase change temperature regulating wall.

[0079] In this embodiment, the sulfoaluminate cementitious material uses a composite formula of 40-50 parts sulfoaluminate cement and 10-20 parts ordinary silicate cement. Through the synergistic effect of the two cements, the rapid hardening and early strength characteristics of sulfoaluminate cement are retained, while the later strength stability is optimized by ordinary silicate cement, and the leakage risk of phase change material is reduced.

[0080] In this embodiment, the sulfoaluminate cement is a solid waste-based sulfoaluminate cement, which, in conjunction with silicate cement and by-product desulfurized building gypsum and mineral powder, forms a composite system. Phase change lightweight aggregate is encapsulated as an aggregate shell, and its SEM image is shown below. Figure 2 As shown, where Figure 2 (a) and Figure 2 (b) In both cases, a large amount of needle-like ettringite produced during the hydration of sulfoaluminate cement forms a robust framework structure, providing excellent mechanical properties; while the calcium silicate hydrate colloid (CSH) formed during the hydration of ordinary silicate cement fills the pores of the framework, making the structure more compact. The crystal-colloid composite system provides aggregate strength and efficient encapsulation, preventing leakage of phase change materials, thus serving a dual purpose. Furthermore, the addition of byproducts such as desulfurized building gypsum and mineral powder not only consumes accumulated solid waste and improves environmental benefits, but also works synergistically to further enhance early strength and rapid setting characteristics, improve construction and production efficiency, and shorten the production cycle.

[0081] In addition, the BSE diagram and energy dispersive spectroscopy results of the aggregate formed by sulfoaluminate cementitious materials are as follows: Figure 3 As shown. Figure 3 As shown, Figure 3 (a) and Figure 3 (b) Shows the microstructure of the expanded perlite and cementitious material shell of the aggregate core, as captured by BSE. Figure 3(c) The results of the energy dispersive spectroscopy (EDS) line scan are shown. Near the interface transition zone of expanded perlite-aggregate shell, the CO element curve on the side closer to expanded perlite shows a high degree of fit, indicating that paraffin is concentrated in this area. However, after entering the aggregate shell area, the fit of the CO element curve gradually decreases until there is no obvious fit, indicating that the shell structure formed by the hydration of sulfoaluminate cementitious material plays an interception role for paraffin and has a good anti-leakage effect.

[0082] Comparative Example 1:

[0083] A phase change temperature regulating wall, which differs from Example 1 in that the phase change lightweight aggregate is not encapsulated and granulated using sulfoaluminate cementitious material.

[0084] If the composite phase change material is not encapsulated, the composite phase change material prepared by mixing 33.3 parts by weight of expanded perlite and 66.7 parts by weight of paraffin wax and baking for 24 hours shows that the leakage rate of the phase change lightweight aggregate can reach 43.9%.

[0085] Example 2

[0086] A phase change temperature regulating wall, using the phase change lightweight aggregate obtained in Example 1, wherein the components are disposed of according to the following mass:

[0087] Phase change lightweight aggregate 2.8kg, gravel 1.8kg, sulfoaluminate cement 2.8kg, ordinary silicate cement 1kg, desulfurized building gypsum 0.7kg, mineral powder 1.2kg, water-reducing agent 30g.

[0088] In this embodiment, the preparation method of the phase change temperature regulating wall is as follows:

[0089] 1) Soak 2.8 kg of the prepared phase change lightweight aggregate in water for 2 hours to make it saturated with water, then remove it and drain the surface water for later use.

[0090] 2) Mix 2.8 kg of sulfoaluminate cement, 1 kg of ordinary silicate cement, 0.7 kg of desulfurized building gypsum, 1.2 kg of mineral powder, and 30 g of water-reducing agent evenly, and then add them to the mixer;

[0091] 3) Add water and stir for 2-3 minutes to form a slurry;

[0092] 4) Add 1.8 kg of gravel and pre-wetted phase change lightweight aggregate, continue stirring for 2-3 minutes, and pour into molds;

[0093] 5) After initial setting, fill with anti-crack layer, steel mesh connection layer, foam insulation layer, etc., to form phase change solar temperature regulating wall exterior wall panel.

[0094] After molding, test blocks were made. The resulting test blocks had a 28-day compressive strength of 48 MPa, a flexural strength of 8 MPa, and an overall density of 1432 kg / m³. It can be used as an external wall structural layer.

[0095] The prepared wall panels are assembled to form a phase-change temperature-regulating wall. A sample room is then constructed using this wall. Without the air conditioning system, temperature fluctuations are reduced compared to a standard sample room, with the highest temperature decreasing by 1.3℃ and the lowest temperature increasing by 2.5℃. With the air conditioning system on, the temperature remains stable throughout the day, with fluctuations below 1%. Despite changes in ambient temperature, the indoor temperature and humidity fluctuate by less than 2% throughout the day, with a minimum temperature of 25.7℃ and a maximum temperature of 26.1℃, maintaining a stable temperature within the human comfort range. This further improves indoor thermal comfort and helps achieve a constant temperature effect.

[0096] Unlike existing thermal bridge insulation materials, this technology incorporates phase change insulation materials into foamed concrete as an insulation layer. While foamed concrete itself has relatively low mechanical properties, it still requires a certain level of strength, and appropriately increasing its strength contributes to the stability of thermal bridge connections. Therefore, considering insulation and phase change heat storage, the strength of the aggregate is also considered to improve its strength as an insulation layer. Furthermore, its application scenario is thermal bridges, specifically the joints where metal connectors such as steel bars and mesh exist in buildings. The thermal conductivity of these parts is significantly higher than that of building materials such as cement and mortar, leading to concentrated heat loss. The thermal bridge loss differs significantly between winter and summer. Existing technologies primarily target regions like Shandong in North China, where the indoor-outdoor temperature difference can reach 30°C in winter due to heating, while in summer it is only around 10°C. Therefore, thermal bridge loss is more severe in winter. According to research, the temperature of thermal bridges is mostly around 10°C in winter. Therefore, existing technologies use octanoic acid with a phase change temperature of around 10°C as a phase change material to reduce thermal bridge losses.

[0097] In this embodiment, the phase change lightweight aggregate is used as a structural concrete layer for a phase change temperature-regulating wall, where the main strength of the concrete comes from the aggregate. Given the already high strength of the concrete, the phase change lightweight aggregate is considered to have a higher heat storage capacity within the phase change temperature-regulating wall, thus giving the structural layer a certain degree of insulation, achieving an integrated function of insulation, protection, and structure. Therefore, in this embodiment, the prepared phase change lightweight aggregate does not focus on strength but rather increases the amount of phase change material to improve the heat storage performance of the concrete.

[0098] Furthermore, in this embodiment, the applicable scenario is a wall. This structural layer, distinct from the insulation layer, is located inside the insulation layer, closer to the interior and thus closer to the indoor temperature. Therefore, incorporating more phase change lightweight aggregate into the phase change temperature-regulating wall can regulate indoor temperature and improve indoor comfort. The ideal indoor human comfort temperature is 25°C; therefore, this embodiment uses 25°C paraffin wax as the phase change material to mitigate indoor temperature fluctuations, stabilizing the indoor temperature at around 25°C. Simultaneously, it reduces HVAC energy consumption in both winter and summer to maintain a comfortable indoor temperature.

[0099] Example 3

[0100] A phase change temperature regulating wall, wherein the components are configured according to the following mass:

[0101] The following components were used: 3.2 kg of phase change lightweight aggregate, 1.2 kg of gravel, 2.45 kg of sulfoaluminate cement, 0.8 kg of ordinary silicate cement, 0.6 kg of desulfurized building gypsum, 1.4 kg of mineral powder, and 30 g of water-reducing agent. The phase change lightweight aggregate obtained in Example 1 was used.

[0102] In this embodiment, the preparation method of the phase change temperature regulating wall is as follows:

[0103] 1) Soak 3.2 kg of the prepared phase change lightweight aggregate in water for 2 hours to make it saturated with water, then remove it and drain the surface water for later use.

[0104] 2) Mix 2.45 kg of sulfoaluminate cement, 0.8 kg of ordinary silicate cement, 0.6 kg of desulfurized building gypsum, 1.4 kg of mineral powder, and 30 g of water-reducing agent evenly, and then add them to the mixer;

[0105] 3) Add water and stir for 2-3 minutes to form a slurry;

[0106] 4) Add 1.8 kg of gravel and pre-wetted phase change lightweight aggregate, continue stirring for 2-3 minutes, and pour into molds;

[0107] 5) After initial setting, fill with crack-resistant layer, steel mesh connection layer, foam insulation layer, etc. to form wall panels. Use the combination of wall panels to obtain phase change temperature regulating wall.

[0108] After molding, test blocks were made. The resulting test blocks had a 28-day compressive strength of 33 MPa, a flexural strength of 6.2 MPa, and an overall density of 1382 kg / m³. It can be used as an external wall structural layer.

[0109] Example 4

[0110] A phase change temperature regulating wall, wherein the components are configured according to the following mass:

[0111] The following ingredients were used: 2 kg of phase change lightweight aggregate, 2.2 kg of gravel, 2.8 kg of sulfoaluminate cement, 1 kg of ordinary silicate cement, 0.7 kg of desulfurized building gypsum, 1.2 kg of mineral powder, and 30 g of water-reducing agent. The phase change lightweight aggregate obtained in Example 1 was used.

[0112] In this embodiment, the preparation method of the phase change temperature regulating wall is as follows:

[0113] 1) Soak 2 kg of the prepared phase change lightweight aggregate in water for 2 hours to make it saturated with water, then remove it and drain the surface water for later use.

[0114] 2) Mix 2.8 kg of sulfoaluminate cement, 1 kg of ordinary silicate cement, 0.7 kg of desulfurized building gypsum, 1.2 kg of mineral powder, and 30 g of water-reducing agent evenly, and then add them to the mixer;

[0115] 3) Add water and stir for 2-3 minutes to form a slurry;

[0116] 4) Add 2.2 kg of gravel and pre-wetted phase change lightweight aggregate, continue stirring for 2-3 minutes, then pour into molds;

[0117] 5) After initial setting, fill with crack-resistant layer, steel mesh connection layer, foam insulation layer, etc. to form wall panels. Use the combination of wall panels to obtain phase change temperature regulating wall.

[0118] After molding, test blocks were made. The resulting test blocks had a 28-day compressive strength of 54 MPa, a flexural strength of 8.7 MPa, and an overall density of 1638 kg / m³. It can be used as an external wall structural layer.

[0119] Comparative Example 2:

[0120] A phase change temperature regulating wall, which differs from Example 2 in that it uses the same volume of expanded perlite / composite phase change material (200g expanded perlite / 600g composite phase change material) to replace the phase change lightweight aggregate in the phase change temperature regulating wall components.

[0121] Phase change temperature regulating walls were prepared according to the preparation method of phase change temperature regulating walls. The resulting test blocks had 28-day compressive strengths of 18 MPa and 21 MPa, and flexural strengths of 1.3 MPa and 1.8 MPa.

[0122] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A phase change temperature regulating wall, characterized in that, This includes phase change concrete, which is composed of the following components in parts by mass: 30-50 parts of phase change lightweight aggregate, 20-30 parts of gravel, 15-20 parts of sulfoaluminate cementitious material, and 10-20 parts of water; The phase change lightweight aggregate is prepared by combining expanded perlite with phase change material paraffin, and the particle size of the phase change lightweight aggregate is 2.35mm-5mm. The sulfoaluminate cementitious material comprises: 40-50 parts of sulfoaluminate cement, 10-20 parts of ordinary silicate cement, 5-10 parts of desulfurized building gypsum, 20-35 parts of mineral powder, and 0.1-0.5 parts of water-reducing agent. The method for preparing the phase change lightweight aggregate includes: Expanded perlite adsorbs paraffin wax, a phase change material, to obtain a composite phase change material. The composite phase change material and the cementitious material are mixed and granulated to obtain phase change lightweight aggregate with a particle size of 2.35mm-5mm; The expanded perlite adsorbs the phase change material paraffin, comprising: Mix 25-33.3 parts by weight of expanded perlite with 66.7-75 parts by weight of paraffin wax and impregnate.

2. The phase change temperature regulating wall as described in claim 1, characterized in that, The impregnation process involves vacuum impregnation for 3-8 hours under negative pressure and at 40-60°C.

3. The phase change temperature regulating wall as described in any one of claims 1-2, characterized in that, The expanded perlite has a particle size of 1.18mm-2.35mm, and the cementing material is sulfoaluminate cementing material.

4. The phase change temperature regulating wall as described in claim 3, characterized in that, The granulation process includes: Composite phase change materials with a particle size distribution of 1.18mm-2.35mm are sieved and added to a granulator; Phase change lightweight aggregate is obtained by granulation.

5. The phase change temperature regulating wall as described in claim 4, characterized in that, When adding the composite phase change material to the granulator, pre-wet it by adding 20%-30% water by weight of the composite phase change material.

6. The phase change temperature regulating wall as described in claim 1, characterized in that, The phase change concrete, combined with the crack-resistant layer, steel mesh connecting layer, and foam insulation layer, forms a wall panel.

7. A method for preparing a phase change temperature-regulating wall as described in any one of claims 1-6, characterized in that, Includes the following steps: Soak the phase change lightweight aggregate, remove it after it becomes saturated with water and drain it to obtain pre-wetted phase change lightweight aggregate; Sulfoaluminate cement, ordinary silicate cement, desulfurized building gypsum, mineral powder, and water-reducing agent are mixed in a certain proportion to obtain a mixed powder. After mixing the powder with water, stir to form a slurry. Add stones and pre-wetted phase change lightweight aggregate to the slurry, continue stirring until evenly mixed, and then pour into molds. After initial setting, a crack-resistant layer, a steel mesh connecting layer, and a foam insulation layer are filled to form a wall panel. The combination of these wall panels creates a phase change temperature regulating wall.

8. The method for preparing the phase change temperature regulating wall as described in claim 7, characterized in that, The prepared phase change lightweight aggregate was soaked in water for 2 hours. After adding water to the mixed powder, it was stirred for 2-3 minutes. After adding the gravel and pre-wetted phase change lightweight aggregate to the slurry, it was stirred for another 2-3 minutes.

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