Composite wall based on phase change microcapsules and elytra bionics and manufacturing method thereof

Abstract

The invention relates to the technical field of composite walls, and discloses a composite wall based on phase change microcapsules and elytrum bionics, one side of the composite wall is provided with an inner phase change layer, the phase change temperature of the inner phase change layer is 24-26 DEG C, one side of the composite wall is provided with an outer phase change layer, and the phase change temperature of the outer phase change layer is 32-34 DEG C. The composite wall further comprises bionic bricks used for building the composite wall, and the bionic bricks are arranged on the outer side of the composite wall. The bionic brick comprises a cube and a sealing cover, the sealing cover is fixedly connected with an opening of the cube through an adhesive, first fins are arranged on the inner wall, close to the inner phase change layer, of the cube, second fins are arranged on the inner wall, close to the outer phase change layer, of the cube, the cube is provided with a stand column, and the upper end of the stand column is fixedly connected with the sealing cover through the adhesive; through the effects of delaying indoor temperature response and reducing artificial room temperature compensation time, the overall carbon emission of the building can be reduced, the method can be widely applied to large-scale cities including Chongqing and the like with the summer high-temperature condition, the method is used for an outer wall heat preservation layer of the building, and the heat loss of the building is greatly reduced while the material consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of composite wall technology, specifically to a composite wall based on phase change microcapsules and elytra biomimicry, and its manufacturing method. Background Technology

[0002] Most buildings in my country have traditional building envelopes with low thermal inertia and poor insulation performance, resulting in 70-80% of energy being dissipated through the building envelope, with the exterior walls accounting for about 30% of the dissipation. This leads to air conditioning systems operating at high loads for extended periods. The prior art discloses (publication number: CN119571964A) a biomimetic wall panel unit, including an insulation layer, a load-bearing layer, a heat insulation layer, and a protective layer. The outer side of the insulation layer has multiple honeycomb cavities. The load-bearing layer is disposed on the outer side of the insulation layer, and the outer side of the load-bearing layer has multiple parallel reinforcing ribs. The heat insulation layer is sprayed on the outer side of the load-bearing layer to bond the load-bearing layer and the protective layer. Thus, the chemical bonding force between the heat insulation layer and the load-bearing layer and the mechanical interlocking force formed by the reinforcing ribs jointly ensure the connection between the two layers. The protective layer is disposed on the outer side of the heat insulation layer, and the inner side of the protective layer has multiple parallel grooves adapted to the reinforcing ribs.

[0003] Existing technologies provide wall panel units with parallel layer-by-layer structures that are functionally independent, avoiding overall wall panel failure due to the failure of a single layer. The partitioned design of the internal cavity structure and external thermal insulation coating reduces the heat transfer coefficient of the wall panel while simultaneously reducing the cavity thickness and coating thickness, achieving high thermal insulation with thin wall panels. However, the existing technology's approach of improving thermal insulation performance by creating honeycomb cavities in the insulation layer is still passive and lacks dynamic heat storage and peak-shaving capabilities. To address these issues, we propose a composite wall based on phase change microcapsules and elytra biomimetic technology, along with its fabrication method. Summary of the Invention

[0004] The present invention aims to provide a composite wall based on phase change microcapsules and elytra biomimetic structures and its manufacturing method, in order to solve the problem that the heat insulation of the existing technology is still passive and lacks dynamic heat storage and peak regulation capabilities.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a composite wall based on phase change microcapsules and elytra biomimicry, wherein the side of the composite wall facing the inside of the building is provided with an inner phase change layer, the phase change temperature of which is 24-26℃, and the side of the composite wall facing the outside of the building is provided with an outer phase change layer, the phase change temperature of which is 32-34℃. The invention also includes biomimetic bricks for assembling the composite wall, each biomimetic brick comprising a cube with an opening and a cap for sealing the opening of the cube. The cap is fixedly connected to the opening of the cube by an adhesive. A first fin is provided on the inner wall of the cube near the inner phase change layer, and a second fin is provided on the inner wall of the cube near the outer phase change layer. A column is provided in the lower middle part of the cube, and the upper end of the column is fixedly connected to the inner wall of the cap by an adhesive.

[0006] The beneficial effects of this plan are: 1. Based on the "honeycomb column" structure of beetle elytra, by setting columns inside the biomimetic brick, the compressive strength and overall structural stability of the biomimetic brick are effectively improved while maintaining its lightweight advantage, thereby enhancing the load-bearing capacity and safety of the composite wall. 2. Because the outer phase change layer faces outwards, hot air is easily generated and rises on the inner wall of the biomimetic brick near the outer phase change layer. However, because the inner phase change layer faces inwards, cold air is easily generated and falls on the inner wall of the biomimetic brick near the inner phase change layer. If the hot and cold air flows naturally in the biomimetic brick, the heat transfer efficiency of the biomimetic brick will increase, thereby reducing the insulation effect of the composite wall. In this solution, the first fin near the inner phase change layer will hinder the fall of the cold air, thereby prolonging the fall time of the cold air. The second fin near the outer phase change layer will hinder the rise of the hot air, thereby reducing the rise speed of the hot air. This weakens the natural convection circulation of the air, reduces the heat transfer efficiency, and improves the insulation effect of the composite wall. 3. In this design, the inner wall of the composite cavity is covered with an inner phase change layer, and the phase change temperature of the inner phase change layer is 24-26℃, which is close to the comfortable temperature of the human body. The phase change temperature of the outer phase change layer is 32-34℃. When the ambient temperature is higher than the temperature of the outer phase change layer, the outer phase change layer can quickly absorb heat, preventing the temperature inside the biomimetic brick from rising, thereby prolonging the time for indoor heating. In areas with large diurnal temperature differences, the outer and inner phase change layers absorb excess heat during the day and then release it at night, thereby reducing the load on the temperature control system and achieving passive regulation of indoor temperature. In areas with small diurnal temperature differences (such as Chongqing), the outer and inner phase change layers can delay the indoor temperature response, stagger peak electricity consumption, and achieve full utilization of electricity.

[0007] Preferably, as an improvement, the inner phase change layer is made of a mixture of a first microcapsule and concrete. The first microcapsule includes a first core material and a shell material for enclosing the first core material. The first core material is composed of n-octadecane and n-hexadecane. The outer phase change layer is made of a mixture of a second microcapsule and concrete. The second microcapsule includes a second core material and a shell material for enclosing the second core material. The second core material is composed of n-octadecane and n-eicosane. The shell materials of both the first and second microcapsules are set as silicon dioxide.

[0008] The beneficial effects are as follows: by encapsulating the first or second core material with a shell material, a first microcapsule and a second microcapsule are formed, allowing the first or second core material to undergo a solid-liquid phase change within the shell material. Compared to the direct application of traditional phase change materials (such as paraffin and fatty acids) into buildings, there are no problems such as leakage, corrosion, or poor cycle stability. Furthermore, the first or second microcapsule is mixed with concrete to form an inner and outer phase change layer. The formed inner and outer phase change layers have significant stability and interfacial compatibility, ensuring the maximization of the heat storage / heat release efficiency of the first and second microcapsules, thereby achieving more efficient and reliable wall heat regulation.

[0009] Preferably, as an improvement, the first core material is made of n-octadecane and n-hexadecane in a molar ratio of 9:1, and the second core material is made of n-octadecane and n-eicosane in a molar ratio of 8:2.

[0010] Preferably, as an improvement, the two ends of the column that come into contact with the cover and the inner wall of the cube are provided with transition arcs.

[0011] The beneficial effects are as follows: the column changes the force transmission to a gradual force transmission through the transition arc. Through the gradual force transmission, the load borne by the column is distributed from the concentration point to a larger contact area, which enhances the load resistance of the wall. Furthermore, when the composite wall is subjected to lateral forces (such as wind force or seismic load), radial friction is generated between the end face of the transition arc and the adhesive, which improves the shear strength of the biomimetic brick.

[0012] Preferably, as an improvement, the cube, the first fin, the second fin, and the column are integrally formed by casting.

[0013] Preferably, as an improvement, the distance between the first fin and the bottom of the cube is set to 30-50mm, and the distance between the second fin and the bottom of the cube is set to 110-130mm.

[0014] Preferably, as an improvement, all four vertical prisms on the inner wall of the cube are rounded.

[0015] The beneficial effects are: the rounded treatment transforms the stress distribution from "sharp corner concentration" to "uniform diffusion" through a smooth transition of the curved surface structure, reducing the risk of structural failure caused by stress fatigue.

[0016] Preferably, as an improvement, the composite wall construction method includes the following steps: S1. Preparation of the first and second microcapsules S1.1: Heat and stir a binary mixture of n-octadecane and n-hexadecane in a molar ratio of 9:1 or a binary mixture of n-octadecane and n-eicosane in a molar ratio of 8:2 until it melts; S1.2: Add tetraethyl orthosilicate and stir until clear; S1.3: Add aluminum oxide and sonicate for 10-15 minutes; S1.4: Add hexadecyltrimethylammonium bromide, deionized water and anhydrous ethanol to form an oil phase mixture, and then emulsify by high-speed shearing for 10 min; S1.5: Adding ammonia solution and graphene oxide dispersion to the oil phase mixture forms a white oil-in-water microemulsion; S1.6: Stir the white oil-in-water microemulsion at room temperature for 24 hours; S1.7: Vacuum filtration separates the first microcapsule or the second microcapsule; S2. Preparation of inner and outer phase change layers S2.1: The first microcapsule is mixed with concrete in a 4:6 ratio to form an inner phase change layer; S2.2: The second microcapsule is mixed with concrete in a 4:6 ratio to form an outer phase change layer; S3, Preparation of biomimetic bricks S3.1: The cube, first fin, second fin, and column are integrally formed by casting; S3.2: Then, seal the cap by casting a single piece; S3.3: Use adhesive to bond the cap to the contact surfaces of the cube and the column; S4, Composite wall structure S4.1: The prepared biomimetic bricks are stacked into a wall using masonry mortar, with the first fin facing inward and the second fin facing outward. At the same time, the columns in each biomimetic brick are perpendicular to the horizontal plane. An inner phase change layer is applied to the side of the wall near the first fin, and an outer phase change layer is applied to the side of the wall near the second fin, thus forming a composite wall.

[0017] This solution reduces overall building carbon emissions by delaying indoor temperature response and reducing the time required for artificial room temperature compensation. It can be widely applied in a wide range of cities with high summer temperatures, including Chongqing, for use in building exterior wall insulation layers, thereby reducing material usage while significantly reducing building heat loss. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the composite cavity structure according to an embodiment of the present invention; Figure 2 This is a partial cross-sectional view of the biomimetic brick according to an embodiment of the present invention; Figure 3 This is a three-dimensional structural diagram of a cube according to an embodiment of the present invention; Figure 4 This is a partial cross-sectional view of the first microcapsule in an embodiment of the present invention. Detailed Implementation

[0019] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: 1. Bionic brick; 2. Cube; 3. Cap; 4. First fin; 5. Second fin; 6. Column; 7. Transition arc; 8. Inner phase change layer; 9. Outer phase change layer; 10. First core material; 11. Aluminum oxide; 12. Silicon dioxide; 13. Graphene oxide.

[0020] Example The basic implementation examples are as follows: Figures 1-4 As shown, Figure 1 The composite wall shown is based on phase change microcapsules and elytra biomimicry, including biomimetic bricks 1 for stacking the composite wall, such as... Figure 2 The biomimetic brick 1 shown includes a cube 2 with an opening and a cap 3 for sealing the opening of the cube 2. The cap 3 is integrally formed by casting a mold and is fixedly connected to the opening at the top of the cube 2 by adhesive. In this embodiment, the thickness of the cap is set to 16mm. As shown in Figure 3, the four vertical prisms on the inner wall of the cube 2 are all rounded. In this embodiment, the length of the cube 2 is set to 290mm, the width to 180mm, and the height to 180mm. The thickness of the bottom base of the cube is set to 16mm, the thickness of the long side is set to 20mm, the thickness of the short side is set to 10mm, and the rounding radius of the four vertical prisms is set to 15mm. Figure 2 The cube 2 shown has a first fin 4 integrally formed on the inner wall of its left end, and the distance between the first fin 4 and the bottom of the cube 2 is set to 30-50mm. In this embodiment, the distance between the first fin 4 and the bottom of the cube 2 is set to 40mm. The cube 2 has a second fin 5 integrally formed on the inner wall of its right end, and the distance between the second fin 5 and the bottom of the cube 2 is set to 110-130mm. In this embodiment, the distance between the second fin 5 and the bottom of the cube 2 is set to 120mm. The length of the first fin 4 and the second fin 5 along the width direction of the biomimetic brick 1 is set to 20mm, and the thickness is set to 10mm. A column 6 is integrally formed in the lower middle part of the cube 2. The upper and lower ends of the column 6 are integrally formed with transition arcs 7, that is, the diameter of the upper and lower ends of the column 6 gradually increases. The upper end of the column 6 is fixedly connected to the inner wall of the cover 3 by adhesive. In this embodiment, the minimum diameter of the column 6 is set to 14mm. In this embodiment, the cube 2, the first fin 4, the second fin 5 and the column 6 are integrally formed by casting a mold.

[0021] like Figure 1The composite wall shown is composed of biomimetic bricks 1 stacked together, and the left end of the composite wall is coated with an inner phase change layer 8. In this embodiment, the coating thickness of the inner phase change layer 8 is set to 30mm. The inner phase change layer 8 is made of a mixture of a first microcapsule and concrete. The first microcapsule includes a first core material 10 and a shell material for encapsulating the first core material 10. The first core material 10 is composed of n-octadecane and n-hexadecane, and the molar ratio of n-octadecane to n-hexadecane is 9:1. At this time, the phase change temperature of the inner phase change layer 8 is 24-26℃, which is close to that of the human body. For comfortable temperature, the right end of the composite wall is coated with an outer phase change layer 9. In this embodiment, the coating thickness of the outer phase change layer 9 is set to 20mm. The outer phase change layer 9 is made of a mixture of second microcapsules and concrete. The second microcapsule includes a second core material and a shell material for wrapping the second core material. The second core material is composed of n-octadecane and n-eicosane, and the molar ratio of n-octadecane to n-eicosane is 8:2. At this time, the phase change temperature of the outer phase change layer 9 is 32-34℃. The shell material of both the first microcapsule and the second microcapsule is set as silicon dioxide 12.

[0022] The method for constructing composite walls includes the following steps: S1. Preparation of the first and second microcapsules S1.1: A binary mixture of n-octadecane and n-hexadecane in a molar ratio of 9:1 or a binary mixture of n-octadecane and n-eicosane in a molar ratio of 8:2 is heated and stirred until melted. In this embodiment, taking the preparation of the first microcapsule as an example, 8.10g of n-octadecane and 0.9g of n-hexadecane are mixed under heating conditions to form the first core material 10. S1.2: Add 3g of tetraethyl orthosilicate and stir until clear; S1.3: Add aluminum oxide 11, and the mass of aluminum oxide is set to one percent of the sum of the masses of n-octadecane and n-hexadecane. In this embodiment, the mass of aluminum oxide 11 is 0.09g, and it is ultrasonically treated for 10-15min. Aluminum oxide 11 can be used as a nucleating agent and mixed with the first core material 10 to reduce the supercooling of the first microcapsule and accelerate the thermal response rate of the first microcapsule. S1.4: Add 0.328g of cetyltrimethylammonium bromide, 25ml of deionized water and 18ml of anhydrous ethanol and stir until homogeneous to form an oil phase mixture. Then emulsify by high-speed shearing for 10min at a speed of 1200r / min. S1.5: Add 10 ml of graphene oxide 13 dispersion to the oil phase mixture and stir evenly. Then add 6 ml of ammonia solution to promote the hydrolysis and condensation reaction of tetraethyl orthosilicate and generate a white oil-in-water microemulsion. During this process, hexadecyltrimethylammonium bromide acts as an emulsifier to help the first core material 10 form a stable water-in-oil microemulsion. In addition, tetraethyl orthosilicate undergoes hydrolysis and condensation reaction under the action of water and ammonia to generate the shell material, namely silicon dioxide 12, with the following chemical formula: Si(OC2H5)4+4H2O→SiO2+4C2H5OH Si(OC2H5)4+4NH3+4H2O→SiO2+4C2H5OH+4NH4OH During this process, graphene oxide 13 forms chemical bonds with silicon dioxide 12, enhancing the stability and thermal conductivity of the first microcapsule; S1.6: Stir the white oil-in-water microemulsion at room temperature for 24 hours; S1.7: The first microcapsules and liquid were rapidly separated by vacuum filtration, and then excess solvent and surfactant were removed by alternating washing with deionized water and anhydrous ethanol. Finally, the first microcapsules were obtained by drying at 60°C for 12 hours. Figure 4 This is a schematic diagram of a partial cross-sectional view of the first microcapsule.

[0023] S2, Prepare inner phase change layer 8 and outer phase change layer 9 S2.1: The first microcapsule is mixed with concrete in a ratio of 4:6 to form an inner phase change layer 8; S2.2: The second microcapsule is mixed with concrete in a ratio of 4:6 to form an outer phase change layer 9.

[0024] S3, Preparation of biomimetic bricks 1 S3.1: The cube 2, the first fin 4, the second fin 5, and the column 6 are integrally formed by casting a model; S3.2: Then, the cap 3 is integrally formed by casting using a mold; S3.3: Use adhesive to bond the cap 3 to the contact surfaces of the cube 2 and the column 6.

[0025] S4, Composite wall structure S4.1: The prepared bionic bricks 1 are stacked into a wall using masonry mortar, with the first fin 4 facing inward and the second fin 5 facing outward. At the same time, the columns 6 in each bionic brick 1 are perpendicular to the horizontal plane. An inner phase change layer 8 is applied to the side of the wall near the first fin 4, and an outer phase change layer 9 is applied to the side of the wall near the second fin 5, thereby forming a composite wall.

[0026] The beneficial effects of this plan are: 1. Based on the "honeycomb column" structure of beetle elytra, this solution sets up a high-hollow space structure in the biomimetic brick 1, and also sets up columns 6 in the biomimetic brick 1. While maintaining the lightweight advantage of the biomimetic brick 1, it effectively improves its compressive strength and overall structural stability, thereby enhancing the load-bearing support performance and safety of the composite wall. 2. Since the outer phase change layer 9 faces outwards, hot air is easily generated and rises on the inner wall of the bionic brick 1 near the outer phase change layer 9. However, since the inner phase change layer 8 faces inwards, cold air is easily generated and falls on the inner wall of the bionic brick 1 near the inner phase change layer 8. If the hot and cold air flows naturally in the bionic brick 1, the heat transfer efficiency of the bionic brick 1 will increase, thereby reducing the heat insulation effect of the composite wall. In this solution, the first fin 4 near the inner phase change layer 8 will hinder the fall of the cold air, thereby prolonging the fall time of the cold air. The second fin 5 near the outer phase change layer 9 will hinder the rise of the hot air, thereby reducing the rise speed of the hot air. This weakens the natural convection circulation of the airflow, reduces the heat transfer efficiency, and improves the heat insulation effect of the composite wall. 3. In this design, the inner wall of the composite cavity is covered with an inner phase change layer 8, and the phase change temperature of the inner phase change layer 8 is 24-26℃, which is close to the comfortable temperature of the human body. The phase change temperature of the outer phase change layer 9 is 32-34℃. When the ambient temperature is higher than the temperature of the outer phase change layer 9, the outer phase change layer 9 can quickly absorb heat to prevent the internal temperature of the biomimetic brick 1 from rising, thereby prolonging the time for indoor heating. In areas with large day-night temperature differences, the outer phase change layer 9 and the inner phase change layer 8 absorb excess heat during the day and then release it at night, thereby reducing the load on the temperature control system and achieving passive regulation of indoor temperature. In areas with small day-night temperature differences (such as Chongqing, Sichuan, etc.), the outer phase change layer 9 and the inner phase change layer 8 can delay the indoor temperature response, stagger peak electricity consumption, and achieve full utilization of electricity.

[0027] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A composite wall based on phase change microcapsules and elytra biomimicry, characterized in that: The composite wall has an inner phase change layer on the side facing inwards, with a phase change temperature of 24-26℃. The composite wall has an outer phase change layer on the side facing outwards, with a phase change temperature of 32-34℃. It also includes biomimetic bricks for building the composite wall. The biomimetic bricks include a cube with an opening and a cap for sealing the opening of the cube. The cap is fixedly connected to the opening of the cube with an adhesive. The cube has a first fin near the inner wall of the inner phase change layer and a second fin near the inner wall of the outer phase change layer. A column is located at the lower center of the cube, and the upper end of the column is fixedly connected to the inner wall of the cap with an adhesive.

2. The composite wall based on phase change microcapsules and elytra biomimicry as described in claim 1, characterized in that: The inner phase change layer is made of a mixture of a first microcapsule and concrete. The first microcapsule includes a first core material and a shell material for enclosing the first core material. The first core material is composed of n-octadecane and n-hexadecane. The outer phase change layer is made of a mixture of a second microcapsule and concrete. The second microcapsule includes a second core material and a shell material for enclosing the second core material. The second core material is composed of n-octadecane and n-eicosane. The shell materials of both the first and second microcapsules are made of silicon dioxide.

3. The composite wall based on phase change microcapsules and elytra biomimicry as described in claim 2, characterized in that: The first core material is made of n-octadecane and n-hexadecane in a molar ratio of 9:1, and the second core material is made of n-octadecane and n-eicosane in a molar ratio of 8:

2.

4. The composite wall based on phase change microcapsules and elytra biomimicry as described in claim 3, characterized in that: The two ends of the column that come into contact with the cover and the inner wall of the cube are provided with transition arcs.

5. The composite wall based on phase change microcapsules and elytra biomimicry as described in claim 4, characterized in that: The cube, the first fin, the second fin, and the column are formed as a single piece through casting.

6. The composite wall based on phase change microcapsules and elytra biomimicry as described in claim 5, characterized in that: The distance between the first fin and the bottom of the cube is set to 30-50mm, and the distance between the second fin and the bottom of the cube is set to 110-130mm.

7. The composite wall based on phase change microcapsules and elytra biomimicry as described in claim 6, characterized in that: The four vertical prisms on the inner wall of the cube are all rounded.

8. A method for constructing composite walls, characterized in that: Includes the following steps: S1. Preparation of the first and second microcapsules S1.1: Heat and stir a binary mixture of n-octadecane and n-hexadecane in a molar ratio of 9:1 or a binary mixture of n-octadecane and n-eicosane in a molar ratio of 8:2 until it melts; S1.2: Add tetraethyl orthosilicate and stir until clear; S1.3: Add aluminum oxide and sonicate for 10-15 minutes; S1.4: Add hexadecyltrimethylammonium bromide, deionized water and anhydrous ethanol to form an oil phase mixture, and then emulsify by high-speed shearing for 10 min; S1.5: Adding ammonia solution and graphene oxide dispersion to the oil phase mixture forms a white oil-in-water microemulsion; S1.6: Stir the white oil-in-water microemulsion at room temperature for 24 hours; S1.7: Vacuum filtration separates the first microcapsule or the second microcapsule; S2. Preparation of inner and outer phase change layers S2.1: The first microcapsule is mixed with concrete in a 4:6 ratio to form an inner phase change layer; S2.2: The second microcapsule is mixed with concrete in a 4:6 ratio to form an outer phase change layer; S3, Preparation of biomimetic bricks S3.1: The cube, first fin, second fin, and column are integrally formed by casting; S3.2: Then, seal the cap by casting a single piece; S3.3: Use adhesive to bond the cap to the contact surfaces of the cube and the column; S4, Composite wall structure S4.1: The prepared biomimetic bricks are stacked into a wall using masonry mortar, with the first fin facing inward and the second fin facing outward. At the same time, the columns in each biomimetic brick are perpendicular to the horizontal plane. An inner phase change layer is applied to the side of the wall near the first fin, and an outer phase change layer is applied to the side of the wall near the second fin, thus forming a composite wall.

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