Adaptive phase change building energy-saving coating and preparation and application thereof

Abstract

The application discloses a self-adaptive phase change building energy-saving coating and a preparation and application thereof, and relates to the technical field of building energy-saving coatings. The self-adaptive phase change building energy-saving coating comprises a phase change base layer and a cover protection layer covering the surface of the phase change base layer. The phase change base layer comprises the following components in mass fractions: 100-150 parts of carbonized cementitious material, 5-30 parts of phase change paraffin, 2-15 parts of expanded perlite, 5-30 parts of a reflecting agent, 200-300 parts of water, 3-10 parts of sodium bicarbonate and 5-8 parts of aluminum sulfate. The cover protection layer comprises the following components in mass fractions: 55-105 parts of an organic emulsion, 10-30 parts of acetone, 1-5 parts of ethanol and 1-10 parts of zirconium dioxide. The phase change material storage frame is prepared by combining radiation refrigeration with phase change materials and using carbonized cementitious material with higher strength. The radiation refrigeration material is more compatible with the building phase change energy storage material, can store more phase change paraffin, enhances the phase change energy storage performance, and can realize the effects of heat insulation and energy saving of the phase change material and the function of radiation refrigeration at the same time.

Description

Technical Field

[0001] This invention relates to the field of building energy conservation technology, and in particular to an adaptive phase change building energy-saving coating and its preparation and application. Background Technology

[0002] With societal development, building energy consumption has become an increasingly serious problem, and traditional building insulation materials and processes are no longer sufficient to meet the demands of building energy conservation. Therefore, developing intelligent, adaptively adjustable new building envelope materials is imperative to achieve building energy efficiency.

[0003] Phase change materials (PCCs) utilize the heat absorption and release properties during phase change to automatically adjust the thermal insulation and heat preservation performance of buildings when the ambient temperature changes, thereby achieving building energy conservation. Specifically, paraffin wax in paraffin capsules is solid at room temperature. When the ambient temperature rises, the paraffin wax undergoes a solid-liquid phase change to become liquid. At this point, the paraffin capsule absorbs and stores heat from the environment, achieving the thermal insulation effect of the coating and preventing the building from absorbing heat. When the ambient temperature decreases, the liquid paraffin releases the stored heat and solidifies. At this point, the paraffin capsule releases the stored heat, achieving the thermal insulation effect of the coating and preventing the building from absorbing heat. Currently, various PCCs are used for building energy conservation, but most are directly added to the building material matrix, reducing the performance of the building material itself, and the adjustment range is limited. Currently, the main application method of paraffin phase change materials is the use of organically encapsulated paraffin capsules, which are added to building materials. However, due to the poor bonding ability between organic paraffin capsules and building materials, the performance of building materials deteriorates significantly. This also limits the amount of paraffin capsules that can be added, resulting in weak phase change energy storage capacity and poor building energy conservation effect.

[0004] Therefore, a solution is needed to improve the energy-saving effect of phase change material coatings in buildings. Summary of the Invention

[0005] In view of this, this application provides an adaptive phase change building energy-saving coating and its preparation and application, which is used to solve the problem of how to improve the building energy-saving effect of phase change material coatings.

[0006] To achieve the above technical objectives, this application adopts the following technical solution:

[0007] In a first aspect, this application provides an adaptive phase change building energy-saving coating, comprising a phase change substrate and a protective overlay layer covering the surface of the phase change substrate; the phase change substrate comprises the following components in parts by weight: 100-150 parts carbonized cementitious material, 5-30 parts phase change paraffin wax, 2-15 parts expanded perlite, 5-30 parts reflector, 200-300 parts water, 3-10 parts sodium bicarbonate, and 5-8 parts aluminum sulfate; the protective overlay layer comprises the following components in parts by weight: 55-105 parts organic emulsion, 10-30 parts acetone, 1-5 parts ethanol, and 1-10 parts zirconium dioxide.

[0008] Preferably, the reflective agent includes one or more of BaSO4, Al2O3, BaTiO3, and ZrO2.

[0009] Preferably, the average particle size of the reflectant is 1000-5000 nm.

[0010] Preferably, the average particle size of zirconium dioxide is 200-500 nm.

[0011] Preferably, the carbonized cementing material is dicalcium γ-silicate.

[0012] Preferably, the ratio of carbonized cementitious material to water is 0.5-2:1.

[0013] Preferably, the thickness of the phase change base layer is 0.4-20 mm, and the thickness of the protective overlay layer is 0.05-100 μm.

[0014] Secondly, this application provides a method for preparing an adaptive phase change building energy-saving coating, comprising the following steps:

[0015] S1. After uniformly mixing carbonized cementitious material, expanded perlite, reflective agent, water, sodium bicarbonate and aluminum sulfate, the mixture is cured in a CO2 atmosphere to obtain a porous framework structure coating.

[0016] S2. Place the porous framework structure coating in molten phase change paraffin wax, and load the phase change paraffin wax using a vacuum loading method to obtain the phase change base layer;

[0017] S3. After the components of the protective coating are mixed evenly, the coating is applied to the surface of the phase change substrate and cured to obtain the adaptive phase change building energy-saving coating.

[0018] Preferably, in step S1, the concentration of CO2 is 3-95% v / v, and the curing temperature is 30-300℃.

[0019] Thirdly, this application provides an application of an adaptive phase change building energy-saving coating in the field of building temperature control.

[0020] The beneficial effects of this application are as follows: This invention combines radiative cooling with phase change materials, and uses carbonized cementitious materials with higher strength to prepare a phase change material storage frame. The radiative cooling material is more compatible with building phase change energy storage materials, and can store more phase change paraffin, enhancing the phase change energy storage performance. This allows it to achieve the heat insulation and energy saving effect of phase change materials, while also adding the function of radiative cooling, strengthening building energy conservation, and preventing overcooling of radiative cooling at night. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] An adaptive phase change building energy-saving coating includes a phase change substrate and a protective overlay layer covering the surface of the phase change substrate; the phase change substrate includes the following components in parts by weight: 100-150 parts carbonized cementitious material, 5-30 parts phase change paraffin wax, 2-15 parts expanded perlite, 5-30 parts reflector, 200-300 parts water, 3-10 parts sodium bicarbonate, and 5-8 parts aluminum sulfate; the protective overlay layer includes the following components in parts by weight: 55-105 parts organic emulsion, 10-30 parts acetone, 1-5 parts ethanol, and 1-10 parts zirconium dioxide.

[0023] The adaptive phase change building energy-saving coating material of this invention has excellent radiative cooling function, with a solar reflectivity and atmospheric window emissivity exceeding 90%. The main frame of this invention is a carbonized cementitious material with excellent reflectivity and emissivity. At the same time, a surface radiative cooling layer is added to the surface to improve the solar spectrum reflectivity and atmospheric window emissivity. The two work together to enhance the radiative cooling effect. The carbonized cementitious material and water form the main frame material under the reaction of carbon dioxide. The addition of expanded perlite, sodium bicarbonate, and aluminum sulfate is to optimize the pore structure of the matrix, forming a connected porous structure, so as to better encapsulate the phase change paraffin. The addition of reflective agent is to improve the overall reflectivity of the matrix.

[0024] The adaptive phase change building energy-saving coating material of the present invention combines phase change function with radiative cooling. It can cool the building surface using radiative cooling and store heat through the energy storage effect of phase change material, thereby reducing heat penetration and improving the effect of radiative cooling in summer. At the same time, the heat storage and release of phase change material at night avoids the overcooling phenomenon of radiative cooling at night.

[0025] In the phase change substrate of this application, the reflective agent has a large bandgap, weak solar absorption capacity, and a high refractive index. This not only facilitates radiative cooling but also prevents photocatalytic decomposition of the phase change paraffin matrix, fully utilizing the high energy storage capacity of the phase change material to enhance radiative cooling. External heat is isolated through the phase change heat storage of the phase change material and the reflection of sunlight by the reflective agent. Furthermore, the phase change temperature of the phase change material can be adjusted to achieve phase change heat storage at different temperature requirements. Expanded perlite effectively increases the number and connectivity of interconnected pores within the coating, which is beneficial for the containment and stability of molten paraffin.

[0026] The protective coating of this application not only protects the coating and prevents the phase change paraffin from flowing out, but also optimizes its surface optical structure by adjusting the composition and phase transformation method, thus achieving the function of partially blocking solar radiation; the double-layer structure of the adaptive phase change building energy-saving coating of this invention protects the paraffin phase change layer and improves solar reflectivity, thereby improving radiative cooling capacity.

[0027] The reflective agent includes one or more of BaSO4, Al2O3, BaTiO3, and ZrO2; preferably, the reflective agent is ZrO2.

[0028] In some embodiments, the average particle size of the reflectant is 1000-5000 nm; the average particle size of zirconium dioxide is 200-500 nm. The particle size of zirconium dioxide differs between the base layer and the top layer. The base layer mainly serves to whiten the surface and supplement it with refractive and scattering effects, so larger particle sizes of powder are selected. The top layer, on the other hand, uses nanomaterials with a particle size of 200-500 nm. This is because nanomaterials with a particle size of 200-500 nm have higher scattering efficiency in organic coatings, which increases the reflectivity of the coating surface.

[0029] The carbonized cementing material is dicalcium γ-silicate.

[0030] The ratio of carbonized cementitious material to water is 0.5-2:1. A high water-to-solid ratio is beneficial to increasing the porosity of the phase change base layer, thereby enhancing the capacity of phase change paraffin to contain the material.

[0031] The thickness of the phase change base layer is 0.4-20mm, and the thickness of the protective cover layer is 0.05-100μm. Since the thermal conductivity of the cover layer is low and radiation mainly occurs on the surface, if it is too thick, the phase change layer will not be able to effectively store heat, and the radiation capacity of the bottom layer will be blocked.

[0032] A method for preparing an adaptive phase change building energy-saving coating includes the following steps:

[0033] S1. After uniformly mixing carbonized cementitious material, expanded perlite, reflective agent, water, sodium bicarbonate and aluminum sulfate, the mixture is cured in a CO2 atmosphere to obtain a porous framework structure coating.

[0034] S2. Place the porous framework structure coating in molten phase change paraffin wax, and load the phase change paraffin wax using a vacuum loading method to obtain the phase change base layer;

[0035] S3. After the components of the protective coating are mixed evenly, the coating is applied to the surface of the phase change substrate and cured to obtain the adaptive phase change building energy-saving coating.

[0036] In step S1, the CO2 concentration is 3-95% v / v, and the curing temperature is 30-300℃.

[0037] This invention first forms an inorganic coating framework. This framework uses a high water-to-solid ratio and a foaming agent to increase its porosity and paraffin-holding capacity. The entire high-strength coating framework acts as a container to load phase change paraffin, and then a highly reflective surface layer is used for encapsulation. This increases the amount of phase change paraffin it can hold.

[0038] This application provides an application of an adaptive phase change building energy-saving coating in the field of building temperature control.

[0039] The following specific embodiments further illustrate this solution.

[0040] Example 1

[0041] An adaptive phase change building energy-saving coating includes a phase change substrate and a protective overlay layer covering the surface of the phase change substrate. The phase change substrate comprises the following components in parts by weight: 100 parts dicalcium γ-silicate, 30 parts phase change paraffin wax, 15 parts expanded perlite, 30 parts ZrO2, 200 parts water, 10 parts sodium bicarbonate, and 8 parts aluminum sulfate. The protective overlay layer comprises the following components in parts by weight: 105 parts organic emulsion, 10 parts acetone, 5 parts ethanol, and 10 parts zirconium dioxide. The average particle size of ZrO2 in the phase change substrate is 1000 nm, and the average particle size of ZrO2 in the protective overlay layer is 200 nm. The thickness of the phase change substrate is 20 mm, and the thickness of the protective overlay layer is 100 μm.

[0042] A method for preparing an adaptive phase change building energy-saving coating includes the following steps:

[0043] S1. After uniformly mixing carbonized cementitious material, expanded perlite, reflective agent, water, sodium bicarbonate, and aluminum sulfate, the mixture is cured in a CO2 atmosphere to obtain a porous framework structure coating; the concentration of CO2 is 3% v / v, and the curing temperature is 30℃.

[0044] S2. Place the porous framework structure coating in molten phase change paraffin wax, and load the phase change paraffin wax using a vacuum loading method to obtain the phase change base layer;

[0045] S3. After the components of the protective coating are mixed evenly, the coating is applied to the surface of the phase change substrate and cured to obtain the adaptive phase change building energy-saving coating.

[0046] Example 2

[0047] An adaptive phase change building energy-saving coating is described, which is otherwise the same as in Example 1, except that the average particle size of the ZrO2 in the phase change substrate is 5000 nm.

[0048] Example 3

[0049] An adaptive phase change building energy-saving coating is the same as in Example 1, except that the average particle size of ZrO2 in the protective coating layer is 500 nm.

[0050] Example 4

[0051] An adaptive phase change building energy-saving coating is the same as in Example 1, except that the mass fraction of water is 300 parts.

[0052] Comparative Example 1

[0053] An energy-saving building coating is the same as in Example 1, except that the phase change substrate does not include ZrO2.

[0054] Comparative Example 2

[0055] An energy-saving building coating is the same as in Example 1, except that the protective coating does not include ZrO2.

[0056] Comparative Example 3

[0057] An energy-saving building coating is the same as in Example 1, except that the phase change substrate does not include phase change paraffin.

[0058] Comparative Example 4

[0059] An energy-saving building coating is the same as in Example 1, except that the average particle size of the ZrO2 in the phase change substrate is 500 nm.

[0060] Comparative Example 5

[0061] An energy-saving building coating is the same as in Example 1, except that the average particle size of the ZrO2 in the protective coating layer is 1000 nm.

[0062] Comparative Example 6

[0063] An energy-saving building coating, otherwise identical to Example 1, except that the preparation method of the adaptive phase change energy-saving building coating includes the following steps:

[0064] S1. After uniformly mixing carbonized cementitious material, expanded perlite, reflective agent, water, sodium bicarbonate, aluminum sulfate, and phase change paraffin, the mixture is cured in a CO2 atmosphere to obtain a porous framework structure coating; the concentration of CO2 is 3% v / v, and the curing temperature is 30℃.

[0065] S2. After the components of the protective coating are mixed evenly, the coating is applied to the surface of the phase change substrate and cured to obtain the adaptive phase change building energy-saving coating.

[0066] Testing and Evaluation

[0067] The energy-saving coatings used in the examples and comparative examples were applied to cement substrates, and temperature tests were conducted inside an insulated chamber with the upper surface of the coating facing the sky. The temperature difference between the coating and the ambient temperature was measured to evaluate its energy-saving effect. The results are shown in Table 1, where negative temperature indicates radiative cooling below ambient temperature.

[0068] Table 1 Test Results

[0069]

[0070] The results show that the present invention can achieve a cooling effect of up to 10 degrees Celsius below the ambient temperature during the day, and can use phase change materials to release heat at night to prevent overcooling, which is reflected in the smaller temperature difference at night.

[0071] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An adaptive phase change building energy-saving coating, characterized in that, The system comprises a phase change substrate and a protective overlay layer covering the surface of the phase change substrate. The phase change substrate comprises the following components in parts by weight: 100-150 parts carbonized cementitious material, 5-30 parts phase change paraffin wax, 2-15 parts expanded perlite, 5-30 parts reflective agent, 200-300 parts water, 3-10 parts sodium bicarbonate, and 5-8 parts aluminum sulfate. The protective overlay layer comprises the following components in parts by weight: 55-105 parts organic emulsion, 10-30 parts acetone, 1-5 parts ethanol, and 1-10 parts zirconium dioxide. It is prepared by the following steps: S1. After uniformly mixing carbonized cementitious material, expanded perlite, reflective agent, water, sodium bicarbonate and aluminum sulfate, the mixture is cured in a CO2 atmosphere to obtain a porous framework structure coating. S2. The porous frame structure coating is placed in molten phase change paraffin wax, and the phase change paraffin wax is loaded using a vacuum loading method to obtain the phase change base layer; S3. After the components of the protective coating are mixed evenly, the coating is applied to the surface of the phase change base layer and cured to obtain the adaptive phase change building energy-saving coating.

2. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, The reflective agent includes one or more of BaSO4, Al2O3, BaTiO3, and ZrO2.

3. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, The average particle size of the reflectant is 1000-5000 nm.

4. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, The average particle size of the zirconium dioxide is 200-500 nm.

5. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, The carbonized cementitious material is dicalcium γ-silicate.

6. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, The ratio of the carbonized cementitious material to water is 0.5-2:

1.

7. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, The thickness of the phase change base layer is 0.4-20 mm, and the thickness of the protective cover layer is 0.05-100 μm.

8. The adaptive phase change building energy-saving coating according to claim 1, characterized in that, In step S1, the CO2 concentration is 3-95% v / v, and the curing temperature is 30-300℃.

9. The application of an adaptive phase change building energy-saving coating as described in any one of claims 1-8 in the field of building temperature control.

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