Low-cost phase-change radiation refrigeration material applied to hog house

Abstract

The invention discloses a low-cost phase-change radiation refrigeration material applied to a pig house. The low-cost phase-change radiation refrigeration material consists of an outer-layer radiation refrigeration material and an inner-layer phase-change material, the outer-layer radiation refrigeration material is prepared from inorganic powder, acrylic resin, deionized water, absolute ethyl alcohol and a binder through ultrasonic blending, the mass ratio of the inorganic powder to the acrylic resin to the deionized water to the absolute ethyl alcohol to the binder is (40-50): (15-20): (10-20): (10-20): (5-10), and the outer-layer radiation refrigeration material can reflect sunlight and emit heat to achieve refrigeration in summer; the inner-layer phase-change material is composed of a phase-change base material and a flexible supporting material, the mass ratio of the phase-change base material to the flexible supporting material is (60-70): (30-40), and the inner-layer phase-change material can store heat through constant-temperature solid-liquid phase change to achieve heat preservation in winter. The phase-change radiation refrigeration material disclosed by the invention can show excellent temperature control performance in spring, summer, autumn and winter, realizes all-weather self-adaptive regulation and control, and has relatively high applicability.

Description

Technical Field

[0001] The present invention belongs to the technical field of building thermal management, and in particular relates to a low-cost phase-change radiation refrigeration material applied to the enclosure structure of a pig house. Background Art

[0002] Pigs' growth and development are highly dependent on a stable ambient temperature. Maintaining an optimal temperature range (typically 15-25°C) is crucial for ensuring healthy growth and improving feed conversion efficiency. However, current pig house temperature control technologies generally face challenges such as high energy consumption and significant pollution. Traditional refrigeration technologies (such as compressor cooling) and heating technologies (such as coal and oil) rely on fossil fuels, generating significant amounts of greenhouse gases during operation. This is not only costly but also contradicts the sustainable development goals of environmentally friendly farming.

[0003] In recent years, radiative cooling materials have garnered attention for their ability to passively cool pig houses by reflecting sunlight and radiating heat into space. However, these materials continue to cool pig houses in winter, leading to excessively low temperatures and requiring additional heating equipment. This further exacerbates energy consumption and environmental pollution, creating a paradoxical situation of "saving energy in summer and wasting energy in winter." Furthermore, existing radiative cooling materials with both high reflectivity and high emissivity are expensive to produce, making them unsuitable for large-scale application within pig house enclosures.

[0004] Phase change materials (PCMs) offer unique advantages in energy storage. By absorbing and releasing latent heat during phase changes, PCMs can store excess indoor heat. The temperature remains stable during the phase change process, effectively buffering against ambient temperature fluctuations. Furthermore, PCMs inherently have low thermal conductivity, acting as a thermal barrier in winter, trapping indoor heat and preventing further heat loss.

[0005] Based on this, there is an urgent need to develop a phase change radiation refrigeration material that is suitable for the special environment of pig houses, low-cost, and integrates phase change energy storage and radiation refrigeration. Through material composite and innovation, full climate adaptive control can be achieved to solve the problems of high energy consumption, high pollution and overcooling in winter of traditional technologies, and provide effective technical support for green and efficient breeding. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a low-cost phase change radiation refrigeration material for use in pig houses, so as to solve the problems of high energy consumption, high pollution and overcooling in winter in existing pig house temperature control technology.

[0007] The technical solutions adopted by the present invention to solve the technical problems are as follows: A low-cost phase-change radiation refrigeration material for use in piggeries comprises an outer layer radiation refrigeration material and an inner layer phase-change material. The outer layer radiation refrigeration material is prepared by ultrasonically blending inorganic powder, acrylic resin, deionized water, anhydrous ethanol, and a binder, wherein the mass ratio of the inorganic powder, acrylic resin, deionized water, anhydrous ethanol, and the binder is (40-50): (15-20): (10-20): (10-20): (5-10). The outer layer radiation refrigeration material can reflect sunlight and emit heat to achieve summer cooling. The inner layer phase-change material comprises a phase-change matrix material and a flexible support material, wherein the mass ratio of the phase-change matrix material to the flexible support material is (60-70): (30-40). The thermal conductivity of the inner layer phase-change material does not exceed 0.3 W / (m·K), and while blocking heat loss, it can store heat through constant-temperature solid-liquid phase change to achieve winter insulation.

[0008] Preferably, the inorganic powder is selected from a mixture of any one or more of alumina, titanium dioxide, silicon dioxide, and barium sulfate; the acrylic resin is selected from one of water-based acrylic resin, elastic acrylic resin, silicon-modified acrylic resin, and thermoplastic acrylic resin; the binder is selected from one of silane coupling agent, chlorinated polypropylene, and maleic anhydride grafted polyethylene; the phase change matrix material is selected from one or more of alkanes, paraffins, fatty acids, and alcohols; and the flexible support material is selected from one or more of polyethylene, olefin block copolymers, polyurethane, biodegradable polymers, polyvinyl alcohol, and polymethyl methacrylate.

[0009] Preferably, the alkanes are one or more of hexadecane, heptadecane, octadecane, tetracosane, etc.; the paraffins are one or more of solid paraffins such as 18#, 20#, 25#, 28#, etc.; the fatty acids are one or more of lauric acid, stearic acid, palmitic acid, sebacic acid, etc.; the alcohols are one or two of 1-tridecanol, lauryl alcohol, etc.

[0010] Preferably, the solar reflectivity of the outer layer radiation cooling material is not less than 88%, and the infrared emissivity is not less than 85%; the outer layer radiation cooling material is combined with the inner layer phase change material by direct coating, the thickness of the outer layer radiation cooling material is 0.7-1.5 mm, and the thickness of the inner layer phase change material is 18-25 mm.

[0011] Preferably, the particle size of the inorganic powder is 0.3-2.5 μm.

[0012] Preferably, the phase change temperature of the inner layer phase change material is 18-28° C., and the heat storage density is 180-220 kJ / kg.

[0013] Preferably, the method for preparing the inner layer phase change material comprises the following steps: A. Raw material selection: Based on weight, select 60-70 parts of phase change matrix material and 30-40 parts of flexible support material; B. High-temperature melt blending: Set the instrument temperature to 10-20°C higher than the melting point of the phase change material, pour the phase change matrix material into a constant temperature oil bath and heat to melt; after the phase change matrix material is fully melted, add the flexible support material, and raise the oil bath temperature to 180-200°C. Heat at a constant temperature and stir thoroughly for a period of time to fully mix the two component materials; C. Medium temperature large area paving: Set the temperature of the constant temperature plate surface to be 5-10℃ higher than the phase change matrix material, pour the evenly mixed molten liquid onto the temperature-controlled large area constant temperature plate surface, and use a scraper to quickly smooth the molten liquid; D. Room temperature cooling and demoulding: After the molten liquid on the surface of the constant temperature plate cools to room temperature, remove the solidified phase change material for later use.

[0014] A pig house enclosure structure includes the phase change radiation cooling material described above. The pig house enclosure structure includes at least one part of the pig house wall or roof. The phase change radiation cooling material is fixed to the outer surface of the pig house enclosure structure by gluing, riveting or wire mesh fixing, and is used to reduce the internal temperature of the pig house in summer and maintain the internal temperature of the pig house stable in winter.

[0015] The low-cost phase-change radiation refrigeration material for piggeries of the present invention has the following positive and beneficial effects: 1. Highly Efficient Summer Cooling Performance: In high summer temperatures (35°C, 60% relative humidity), piggeries using the present invention's material experienced an average 7°C lower internal temperature than those without the material. The outer layer's radiative cooling material boasts a solar reflectivity of 90% and an infrared emissivity of 88%, effectively reflecting sunlight and emitting heat, significantly reducing internal temperatures. While traditional refrigeration technologies (such as compressor cooling) consume high energy in high-temperature environments, the present invention's passive cooling reduces the frequency of refrigeration equipment use, resulting in an average summer temperature reduction of 4.83°C and a 32.5% reduction in energy consumption.

[0016] 2. Excellent winter thermal insulation: In low winter temperatures (5°C, 40% relative humidity), piggeries using the present invention's material experience an average 4°C increase in internal temperature compared to piggeries without the material. The inner layer's phase change material, with a phase change temperature of 20°C and a heat storage density of 200kJ / kg, absorbs and releases heat during the winter, effectively maintaining a stable internal temperature. Furthermore, the low thermal conductivity of the phase change material further prevents heat loss to the outside environment. Traditional heating technologies (such as coal and oil) rely on fossil fuels, resulting in high operating costs and significant pollution. However, the present invention's phase change energy storage reduces the need for additional heating equipment, resulting in an average winter temperature increase of 2.92°C and a 29.5% reduction in average energy consumption.

[0017] 3. Significant cost-effectiveness: The preparation cost of this material is approximately 40% lower than that of existing radiative cooling materials. The outer layer of the radiative cooling material utilizes a self-made white emulsion coating, made from readily available and inexpensive raw materials. The inner layer of the phase change material is simple to prepare, making it suitable for large-scale production. Existing radiative cooling materials are expensive to prepare and unsuitable for large-scale use. However, this material significantly reduces costs while maintaining performance, resulting in high economic efficiency.

[0018] 4. Environmental friendliness: After using the material of the present invention, the energy consumption for cooling and heating in pig houses is significantly reduced, and greenhouse gas emissions are reduced by about 30%. The material does not rely on fossil energy during use and does not produce greenhouse gas emissions, which is in line with the sustainable development goals of green farming. Traditional temperature control technology relies on fossil energy and produces a large amount of greenhouse gases during operation. The material of the present invention reduces energy consumption and environmental pollution through passive refrigeration and phase change energy storage.

[0019] 5. All-Climate Adaptive Control: The material of this invention exhibits excellent temperature control performance in both summer and winter, automatically adjusting the internal temperature of the piggery according to seasonal changes, achieving all-climate adaptive control. Existing temperature control technologies require separate cooling and heating equipment in summer and winter, which consumes high energy and requires complex equipment. However, through material combination and innovation, the material of this invention achieves automatic temperature control year-round, simplifying the temperature control system.

[0020] A. Experimental Materials: Outer layer radiation cooling material: prepared from inorganic powder (aluminum oxide), acrylic resin (water-based acrylic resin), deionized water, anhydrous ethanol and binder (silane coupling agent) in a mass ratio of 40:15:20:20:5.

[0021] Inner layer phase change material: phase change matrix material (hexadecane) and flexible support material (polyethylene) are prepared in a mass ratio of 65:35.

[0022] B. Experimental environment: Summer experiment: Zhengzhou City, Henan Province, June 17, 2025, the measured temperature on that day was 30-38℃, and the relative humidity was 60%.

[0023] Winter experiment: Zhengzhou City, Henan Province, January 22, 2025, the measured temperature on that day was 3-10℃, and the relative humidity was 40%.

[0024] C. Experimental equipment: Temperature sensor: used to monitor the internal and external temperature of the pig house in real time.

[0025] Infrared thermal imager: used to measure the surface temperature distribution of materials.

[0026] Solar reflectance and infrared emissivity tester: used to measure the optical properties of outer radiation cooling materials.

[0027] Heat flow meter: used to measure heat transfer through a material.

[0028] Small simulated weather station: used to record ambient temperature, humidity and solar radiation intensity during the experiment.

[0029] D. Experimental methods: (1) Summer cooling performance test: (1) Material preparation: Prepare an outer layer of radiative cooling material and an inner layer of phase change material according to the method in the claims, and then coat the outer layer material on the surface of the inner layer material to form a composite material.

[0030] (2) Experimental setting: area of ​​112m 2 The small pig house, with a capacity of 100 pigs, has precast reinforced concrete outer walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Composite materials are attached to the outer walls and roof of the pig house. Temperature sensors are installed on the material surface and inside the pig house, and the surface temperature is recorded using an infrared thermal imager.

[0031] (3) Data recording: Record the surface temperature of the material and the temperature inside the pig house once every hour, and make a temperature change curve within a day.

[0032] (4) Energy consumption monitoring: Install temperature sensors in the pig house to record energy consumption data before and after the use of the material of the present invention; use a heat flow meter to measure the heat transfer through the material and calculate the reduction in refrigeration energy consumption.

[0033] (2) Winter thermal insulation performance test: (1) Material preparation: Prepare the outer layer radiation cooling material and the inner layer phase change material according to the method in the claims, and coat the outer layer material on the surface of the inner layer material to form a composite material.

[0034] (2) Experimental setting: area of ​​112m 2 The small pig house, with a capacity of 100 pigs, has precast reinforced concrete outer walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Composite materials are attached to the outer walls and roof of the pig house. Temperature sensors are installed on the material surface and inside the pig house, and the surface temperature is recorded using an infrared thermal imager.

[0035] (3) Data recording: Record the surface temperature of the material and the temperature inside the pig house once every hour, and make a temperature change curve within a day.

[0036] (4) Energy consumption monitoring: Install temperature sensors in the pig house to record energy consumption data before and after the use of the material of the present invention; use a heat flux meter to measure the heat transfer through the material and calculate the reduction in heating energy consumption.

[0037] E. Experimental results: (1) Summer cooling performance: (1) Solar reflectivity and infrared emissivity: The solar reflectivity of the outer layer of radiation cooling material is 90%, and the infrared emissivity is 88%.

[0038] (2) Temperature change curve: In the high temperature environment in summer (ambient temperature 30-38℃, relative humidity 60%), the internal temperature of the pig house is 4-5℃ lower than that of the pig house without using materials; the surface temperature of the material is 2-3℃ lower than the ambient temperature, showing a good cooling effect.

[0039] (3) Energy consumption analysis: After using this material, the average energy consumption of pig house cooling was reduced by 32.5%.

[0040] The specific data of the summer cooling experiment are shown in the following table:

[0041] (4) Calculation of energy consumption reduction rate (%): The relationship between the energy consumption reduction rate and the temperature before and after the use of the material is indirect. The energy consumption reduction rate mainly reflects the energy consumption saved by regulating the temperature inside the pig house after using the phase change radiation refrigeration material: ① Temperature regulation requirements: When the low-cost phase-change radiation refrigeration material of the present invention is not used, the temperature inside the pig house is high, which means that more energy is needed to lower the temperature to achieve a suitable breeding environment; after using the phase-change radiation refrigeration material, due to the radiation cooling and phase-change energy storage characteristics of the material, the temperature inside the pig house is effectively regulated, thereby reducing the need for additional temperature regulation.

[0042] ② Energy consumption: In summer, the temperature inside the pig house without the material is higher, and more air-conditioning energy may be needed to cool down. After using the low-cost phase change radiation refrigeration material of the present invention, the temperature inside the pig house is reduced due to the cooling effect of the material, which reduces the use of air conditioning and thus reduces energy consumption.

[0043] ③Energy consumption reduction rate: It is calculated by comparing the energy consumption before and after using the material. E0 is the energy consumption before using the material, E1 is the energy consumption after using the material, ΔE is the difference in energy consumption, ΔE= E0-E1.

[0044] For each time period, the percentage of energy consumption reduction is calculated as follows: Reduction% = ΔE / E0 × 100%.

[0045] (2) Winter thermal insulation performance: (1) Phase change temperature and heat storage density: The phase change temperature of the inner layer phase change material is 20°C, and the heat storage density is 200kJ / kg.

[0046] (2) Temperature change curve: In the low temperature environment in winter (ambient temperature 3-10℃, relative humidity 40%), the internal temperature of the pig house is 2.92℃ higher than that of the pig house without using materials; the surface temperature of the material is 3-5℃ higher than the ambient temperature, showing a good thermal insulation effect.

[0047] (3) Energy consumption analysis: After using this material, the heating energy consumption of the pig house was reduced by 29.5%.

[0048] The specific data of the winter heating experiment are shown in the following table:

[0049] F. Cost accounting: The preparation cost of the material is about 40% lower than that of existing radiation cooling materials.

[0050] The specific cost comparison is shown in the following table:

[0051] G. Environmental benefits: After using the material of the present invention, the energy consumption for cooling and heating of pig houses is significantly reduced, and greenhouse gas emissions are reduced by about 30%.

[0052] Experimental results demonstrate that the phase-change radiative cooling material exhibits excellent temperature control performance in both summer and winter, effectively regulating the internal temperature of piggeries and reducing energy consumption. In summer, the average temperature was reduced by 4.83°C, with an average energy consumption reduction of 32.5%. In winter, the average temperature was increased by 2.92°C, with an average energy consumption reduction of 29.5%. These results demonstrate the seasonal applicability and high efficiency of the phase-change radiative cooling material, providing an innovative, low-cost, and environmentally friendly solution for piggery temperature control. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic diagram of the structure of the low-cost phase-change radiative cooling material of the present invention applied to the wall of a pig house. In the figure, 1 is the pig house wall, 2 is the inner layer of phase-change material, and 3 is the outer layer of radiative cooling material. The outer layer of radiative cooling material 3 is coated on the surface of the inner layer of phase-change material 2 to form a composite material. The composite material is then fixed to the outer surface of the pig house wall structure by gluing, riveting, or fixing with a wire mesh. It is used to reduce the internal temperature of the pig house in summer and maintain the internal temperature stability in winter. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be further explained and illustrated below in conjunction with embodiments and specific application examples: Example 1: A low-cost phase-change radiation refrigeration material for use in pig houses, consisting of an outer layer radiation refrigeration material and an inner layer phase-change material; the outer layer radiation refrigeration material is prepared by ultrasonic blending of inorganic powder, acrylic resin, deionized water, anhydrous ethanol and a binder, wherein the mass ratio of the inorganic powder, acrylic resin, deionized water, anhydrous ethanol and the binder is (40-50): (15-20): (10-20): (10-20): (5-10), the outer layer radiation refrigeration material can reflect sunlight and emit heat to achieve summer cooling; the inner layer phase-change material is composed of a phase-change matrix material and a flexible support material, the mass ratio of the phase-change matrix material to the flexible support material is (60-70): (30-40), the thermal conductivity of the inner layer phase-change material does not exceed 0.3 W / (m·K), and while blocking heat loss, it can store heat through constant-temperature solid-liquid phase change to achieve winter insulation.

[0055] The inorganic powder is selected from one or more of aluminum oxide, titanium dioxide, silicon dioxide, and barium sulfate; the acrylic resin is selected from one of water-based acrylic resin, elastic acrylic resin, silicon-modified acrylic resin, and thermoplastic acrylic resin; the binder is selected from one of silane coupling agent, chlorinated polypropylene, and maleic anhydride grafted polyethylene; the phase change matrix material is selected from one or more of alkanes, paraffins, fatty acids, and alcohols; and the flexible support material is selected from one or more of polyethylene, olefin block copolymers, polyurethane, biodegradable polymers, polyvinyl alcohol, and polymethyl methacrylate.

[0056] The alkanes are one or more of hexadecane, heptadecane, octadecane, tetracosane, etc.; the paraffins are one or more of solid paraffins such as 18#, 20#, 25#, 28#, etc.; the fatty acids are one or more of lauric acid, stearic acid, palmitic acid, sebacic acid, etc.; the alcohols are one or two of 1-tridecanol, lauryl alcohol, etc.

[0057] The outer layer radiation cooling material has a solar reflectivity of not less than 88%, and an infrared emissivity of not less than 85%; the outer layer radiation cooling material is combined with the inner layer phase change material by direct coating, the thickness of the outer layer radiation cooling material is 0.7-1.5 mm, and the thickness of the inner layer phase change material is 18-25 mm.

[0058] The particle size of the inorganic powder is 0.3-2.5 μm.

[0059] The phase change temperature of the inner layer phase change material is 18-28° C., and the heat storage density is 180-220 kJ / kg.

[0060] The preparation method of the inner layer phase change material comprises the following steps: A. Raw material selection: Based on weight, select 60-70 parts of phase change matrix material and 30-40 parts of flexible support material; B. High-temperature melt blending: Set the instrument temperature to 10-20°C higher than the melting point of the phase change material, pour the phase change matrix material into a constant temperature oil bath and heat to melt; after the phase change matrix material is fully melted, add the flexible support material, and raise the oil bath temperature to 180-200°C. Heat at a constant temperature and stir thoroughly for a period of time to fully mix the two component materials; C. Medium temperature large area paving: Set the temperature of the constant temperature plate surface to be 5-10℃ higher than the phase change matrix material, pour the evenly mixed molten liquid onto the temperature-controlled large area constant temperature plate surface, and use a scraper to quickly smooth the molten liquid; D. Room temperature cooling and demoulding: After the molten liquid on the surface of the constant temperature plate cools to room temperature, remove the solidified phase change material for later use.

[0061] Example 2, see Figure 1 A pig house enclosure structure includes a pig house wall 1, an inner layer of phase change material 2 and an outer layer of radiation cooling material 3. The outer layer of radiation cooling material 3 is coated on the surface of the inner layer of phase change material 2 to form a composite material. The composite material is fixed to the outer surface of the pig house wall 1 by pasting, riveting or wire mesh fixing, and is used to reduce the internal temperature of the pig house in summer and maintain the stability of the internal temperature of the pig house in winter.

[0062] Application Example 1: Summer cooling effect test: Objective: To verify the cooling effect of phase change radiative cooling materials under high temperature conditions in summer.

[0063] Material preparation: ① The outer layer radiation cooling material is prepared from alumina, water-based acrylic resin, deionized water, anhydrous ethanol and silane coupling agent in a mass ratio of 40:15:20:20:5; ② The inner layer phase change material is prepared from hexadecane and polyethylene in a mass ratio of 65:35; ③ The outer layer radiation cooling material is coated on the surface of the inner layer phase change material to form a composite material.

[0064] Experimental setting: area of ​​112m 2 A small pig house with a capacity of 100 pigs has precast reinforced concrete outer walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Composite materials are attached to the outer walls and roof of the pig house, and temperature sensors are installed on the surface of the materials and inside the pig house.

[0065] Experimental results: At an ambient temperature of 35°C, the internal temperature of the pig house without the material was 38°C, but after using the material, it was 33°C, a temperature drop of 5°C. Energy consumption reduction: Without the material, the temperature was 7kWh, while after using the material, it was 4.6kWh, a reduction of 34.3%.

[0066] Application example 2: Winter insulation effect test: Objective: To verify the thermal insulation effect of phase change radiative refrigeration materials under low temperature conditions in winter.

[0067] Material preparation: ① The outer layer radiation cooling material is prepared from alumina, water-based acrylic resin, deionized water, anhydrous ethanol and silane coupling agent in a mass ratio of 40:15:20:20:5; ② The inner layer phase change material is prepared from 28# solid paraffin and olefin block copolymer in a mass ratio of 60:40; ③ The outer layer radiation cooling material is coated on the surface of the inner layer phase change material to form a composite material.

[0068] Experimental setting: area of ​​112m 2A small pig house with a capacity of 100 pigs has precast reinforced concrete outer walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Composite materials are attached to the outer walls and roof of the pig house, and temperature sensors are installed on the surface of the materials and inside the pig house.

[0069] Experimental results: At an ambient temperature of 5°C, the internal temperature of the pig house without the material was 9°C, but after using the material, it was 12°C, a temperature increase of 3°C. Energy consumption reduction rate: Without the material, it was 4kWh, and after using the material, it was 2.8kWh, a 30% reduction.

[0070] Application Example 3: Annual Energy Consumption Monitoring: Objective: To monitor the energy consumption of piggeries using the materials of the present invention throughout the year.

[0071] Experimental setup: Energy consumption of a piggery using the material of the present invention was monitored in different seasons.

[0072] Experimental results: In spring and autumn, energy consumption decreased by about 27.8%; in summer, the average energy consumption for pig house cooling decreased by 32.5%; and in winter, the energy consumption for pig house heating decreased by 29.5%.

[0073] Based on the data for the whole year, energy consumption was reduced by an average of about 30%.

[0074] Application Example 4: Performance test under different environmental conditions: Purpose: To test the performance of the material of the present invention under different environmental conditions.

[0075] Experimental results: Under different environmental conditions, the internal temperature of the pig house varied between 2.5-5.5°C, showing good adaptability; energy consumption was reduced between 25%-35%, proving the material's high efficiency and energy-saving characteristics.

[0076] Application Example 5: Comparison of different phase change materials: Objective: To evaluate the effects of different phase change materials on temperature control performance.

[0077] Material preparation: ① Outer layer radiation cooling material: prepared from titanium dioxide, silicon-modified acrylic resin, deionized water, anhydrous ethanol and chlorinated polypropylene in a mass ratio of 40:15:20:20:5; ② Inner layer phase change material A: prepared from stearic acid and polyurethane in a mass ratio of 70:30; ③ Inner layer phase change material B: prepared from 1-tridecanol and polyvinyl alcohol in a mass ratio of 60:40.

[0078] Experimental setting: area of ​​112m 2A small pig house with a capacity of 100 pigs has precast reinforced concrete outer walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Two different inner layer phase change materials A and B are respectively compounded with the outer layer radiant cooling material and applied to the outer walls and roof of the pig house, covering an area of ​​1m². Temperature sensors are installed on the material surface and inside the pig house.

[0079] Experimental results: In summer, the internal temperature of the pig house using inner layer phase change material A decreased by an average of 4.5°C, and energy consumption decreased by 32%; the internal temperature of the pig house using inner layer phase change material B decreased by an average of 4.8°C, and energy consumption decreased by 35%.

[0080] Application Example 6: Testing of composite materials of different thicknesses: Purpose: To study the effect of composite material thickness on temperature control performance.

[0081] Material preparation: ① Outer layer radiation cooling material: prepared from titanium dioxide, silicon-modified acrylic resin, deionized water, anhydrous ethanol and chlorinated polypropylene in a mass ratio of 40:15:20:20:5; ② Inner layer phase change material: prepared from hexadecane and polyethylene in a mass ratio of 65:35.

[0082] Experimental setting: area of ​​112m 2 A small pig house with a stock of 100 pigs has precast reinforced concrete outer walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Composite materials of different thicknesses (1.5mm, 2.0mm, 2.5mm) were prepared and applied to the outer walls and roof of the pig house. Temperature sensors were installed on the surface of the materials and inside the pig house.

[0083] Experimental results: ① Composite materials with a thickness of 1.5 mm reduced the internal temperature of the pig house by an average of 4.2°C in summer and energy consumption by 30%; ② Composite materials with a thickness of 2.0 mm reduced the temperature by an average of 4.8°C and energy consumption by 35%; ③ Composite materials with a thickness of 2.5 mm reduced the temperature by an average of 5.1°C and energy consumption by 38%.

[0084] Application Example 7: Application effects under different climatic conditions: Purpose: To evaluate the effectiveness of materials under different climatic conditions.

[0085] Material preparation: ① The outer layer radiation cooling material is prepared from silica, thermoplastic acrylic resin, deionized water, anhydrous ethanol and maleic anhydride grafted polyethylene in a mass ratio of 40:20:20:10:10; ② The inner layer phase change material is prepared from lauric acid and biodegradable polymer in a mass ratio of 70:30.

[0086] Experimental setup: Composite materials were applied to the exterior walls and roofs of piggeries in different climates (tropical, subtropical, and temperate). The piggeries were approximately 100 m² in area and constructed of reinforced concrete. Temperature sensors were installed on the material surface and inside the piggeries.

[0087] The experimental results showed that: ① In tropical climates, the composite materials reduced the internal temperature of the pig house by an average of 5.5°C and energy consumption by 40%; ② In subtropical climates, the temperature was reduced by an average of 4.8°C and energy consumption by 35%; ③ In temperate climates, the temperature was reduced by an average of 4.2°C and energy consumption by 30%.

[0088] Application Example 8: Testing of long-term application performance: Objective: To evaluate the performance stability of the material of the present invention in long-term application.

[0089] Material preparation: ① The outer layer radiation cooling material is prepared from silica, thermoplastic acrylic resin, deionized water, anhydrous ethanol and maleic anhydride grafted polyethylene in a mass ratio of 40:20:10:20:10; ② The inner layer phase change material is prepared from lauric acid and biodegradable polymer in a mass ratio of 70:30.

[0090] Experimental setting: area of ​​112m 2 A small pig house with a capacity of 100 pigs has precast reinforced concrete exterior walls (outer protective layer: 30mm thick C30 fine stone concrete, insulation layer: 50mm thick XPS extruded board, structural layer: 150mm thick reinforced concrete + cold-drawn steel wire mesh; inner surface layer: 15mm thick plaster mortar). The wall heat transfer coefficient K = 1.2W / (m²·K). Composite materials were applied to the exterior walls and roof of the pig house. A one-year monitoring period was conducted, with temperature changes and energy consumption data regularly recorded.

[0091] Experimental results: In spring and autumn, energy consumption decreased by about 27.8%; in summer, the average energy consumption for pig house cooling decreased by 32.5%; in winter, the energy consumption for pig house heating decreased by 29.5%; based on the comprehensive data for the whole year, the average energy consumption decreased by about 30%, showing good long-term stability and energy-saving effects.

[0092] In summary: The phase change radiation refrigeration material of the present invention can exhibit excellent temperature control performance in spring, summer, autumn and winter, can effectively regulate the internal temperature of the pig house, reduce energy consumption, has high applicability, and provides an innovative, low-cost and environmentally friendly solution for pig house temperature control.

Claims

1. A low-cost phase-change radiation refrigeration material for piggeries, characterized by: The phase change radiation refrigeration material consists of an outer layer radiation refrigeration material and an inner layer phase change material; the outer layer radiation refrigeration material is prepared by ultrasonic blending of inorganic powder, acrylic resin, deionized water, anhydrous ethanol and binder, wherein the mass ratio of inorganic powder, acrylic resin, deionized water, anhydrous ethanol and binder is (40-50): (15-20): (10-20): (10-20): (5-10), the outer layer radiation refrigeration material can reflect sunlight and emit heat to achieve summer cooling; the inner layer phase change material consists of a phase change matrix material and a flexible support material, the mass ratio of the phase change matrix material to the flexible support material is (60-70): (30-40), the thermal conductivity of the inner layer phase change material does not exceed 0.3 W / (m·K), and while blocking heat loss, it can store heat through constant temperature solid-liquid phase change to achieve winter insulation.

2. The low-cost phase-change radiation refrigeration material for piggeries according to claim 1, characterized in that: The inorganic powder is selected from one or more of aluminum oxide, titanium dioxide, silicon dioxide, and barium sulfate; the acrylic resin is selected from one of water-based acrylic resin, elastic acrylic resin, silicon-modified acrylic resin, and thermoplastic acrylic resin; the binder is selected from one of silane coupling agent, chlorinated polypropylene, and maleic anhydride grafted polyethylene; the phase change matrix material is selected from one or more of alkanes, paraffins, fatty acids, and alcohols; and the flexible support material is selected from one or more of polyethylene, olefin block copolymers, polyurethane, biodegradable polymers, polyvinyl alcohol, and polymethyl methacrylate.

3. The low-cost phase-change radiation refrigeration material for piggeries according to claim 2, characterized in that: The alkanes are one or more of hexadecane, heptadecane, octadecane, tetracosane, etc.; the paraffins are one or more of solid paraffins such as 18#, 20#, 25#, 28#, etc.; the fatty acids are one or more of lauric acid, stearic acid, palmitic acid, sebacic acid, etc.; the alcohols are one or two of 1-tridecanol, lauryl alcohol, etc.

4. The low-cost phase-change radiation refrigeration material for piggeries according to claim 1, characterized in that: The outer layer radiation cooling material has a solar reflectivity of not less than 88%, and an infrared emissivity of not less than 85%; the outer layer radiation cooling material is combined with the inner layer phase change material by direct coating, the thickness of the outer layer radiation cooling material is 0.7-1.5 mm, and the thickness of the inner layer phase change material is 18-25 mm.

5. The low-cost phase-change radiation refrigeration material for piggeries according to claim 1, characterized in that: The particle size of the inorganic powder is 0.3-2.5 μm.

6. The low-cost phase-change radiation refrigeration material for piggeries according to claim 1, characterized in that: The phase change temperature of the inner layer phase change material is 18-28° C., and the heat storage density is 180-220 kJ / kg.

7. The low-cost phase change radiation refrigeration material for pig houses according to claim 1, characterized in that: The preparation method of the inner layer phase change material comprises the following steps: A. Raw material selection: Based on weight, select 60-70 parts of phase change matrix material and 30-40 parts of flexible support material; B. High-temperature melt blending: Set the instrument temperature to 10-20°C higher than the melting point of the phase change material, pour the phase change matrix material into a constant temperature oil bath and heat to melt; after the phase change matrix material is fully melted, add the flexible support material, and raise the oil bath temperature to 180-200°C. Heat at a constant temperature and stir thoroughly for a period of time to fully mix the two component materials; C. Medium temperature large area paving: Set the temperature of the constant temperature plate surface to be 5-10℃ higher than the phase change matrix material, pour the evenly mixed molten liquid onto the temperature-controlled large area constant temperature plate surface, and use a scraper to quickly smooth the molten liquid; D. Room temperature cooling and demoulding: After the molten liquid on the surface of the constant temperature plate cools to room temperature, remove the solidified phase change material for later use.

8. A pig house enclosure structure, characterized by: The phase-change radiation refrigeration material comprises the phase-change radiation refrigeration material according to any one of claims 1 to 6, the pig house enclosure structure comprises at least one part in the pig house wall or roof, and the phase-change radiation refrigeration material is fixed to the outer surface of the pig house enclosure structure by gluing, riveting or wire mesh fixing, and is used to reduce the internal temperature of the pig house in summer and keep the internal temperature of the pig house stable in winter.

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