Method for manufacturing phase change material heat storage microcapsule powder
Manufacturing process
1. Calcium carbide slag
2. Melting
3. Na2CO3 + stone residue (calcium carbide slag)
4. Mixing
5. Polyvinyl alcohol core mixing
6. Pneumatic compression
7. Sintering: A process of applying temperature and pressure to make large particles with a specific surface area such as powder into a more dense mass. Through the sintering process, the density, porosity, and pore size distribution of the material can be controlled, and the desired properties can be realized.
8. Phase change microcapsule powder
Through the composite sensory heat storage and composite phase change heat storage materials, composite phase change heat storage technology, reasonable heat storage technology, and phase change heat storage technology to avoid many shortcomings, has become a hot topic at home and abroad in recent years, but the traditional skeletal materials use natural minerals or their by-products.
Large-scale mining or processing destroys the local ecological environment and consumes a large amount of fossil energy. In order to reduce the environmental impact of the above problems, solid waste can be used to prepare composite phase change heat storage materials.
Calcium carbide slag and acetylene. Polyvinyl chloride and other industrial solid wastes generated during the production process, China produces more than 50 million tons per year, and the use of calcium carbide slag in the cement industry is saturated. It causes a large amount of calcium carbide slag to accumulate in the open air. It causes serious damage to the local ecosystem, and new resource utilization methods should be explored.
In order to absorb large quantities of industrial solid waste calcium carbide slag and prepare low-carbon and low-cost composite phase change heat storage materials, researchers from Beijing University of Civil Engineering and Architecture proposed to use calcium carbide slag as the skeleton material to prepare Na2CO3/calcium carbide slag composite phase change heat storage materials by cold-pressing sintering method, and the specific steps are shown in the figure. Considering the deformation, surface solution salt leakage and heat storage density, although the heat storage density of the NC4 sample is the largest among the three composite phase change heat storage materials, the mass ratio of the composite phase change heat storage material corresponding to the sample NC5 is considered to be the optimal ratio. After that, our team analyzed the macroscopic morphology, heat storage performance, mechanical properties of the composite phase change heat storage material, microscopic morphology, cycle stability and material component compatibility, and mainly got the following conclusions:
1. Calcium carbide slag components have good compatibility with Na2CO3. Na2CO3/calcium carbide slag can replace the traditional natural skeleton material to synthesize composite phase change heat storage material, and realize the low-carbon and low-cost composition of composite phase change heat storage material with the large-scale resource recycling of calcium carbide slag.
2. 52.5% calcium carbide slag and 47.5% phase change material Na2CO3/composite material can be used to prepare composite phase change heat storage material with excellent performance. No fluctuation and no leakage., the thermal storage density of up to 993 J/g, the compressive strength of 22.02 MPa, the thermal conductivity of 0.62 W/((m•K) within 100 ~ 900 °C, the thermal storage performance of sample NC5 was maintained stably.
3. The thickness of the film layer determines the interparticle force of the framework material and the compressive strength of the composite screen change heat storage material. And the composite screen change heat storage material has the best mechanical properties when it is prepared with the maximum mass release.
4. The thermal conductivity of the framework material particles is the main factor affecting the heat transfer performance of the composite screen change heat storage material. And the penetration and absorption of the phase change material into the force structure of the framework material improves the thermal conductivity of the framework material particles, thus improving the heat transfer performance of the composite screen change heat storage material.
Energy storage phase change materials have the advantages of high energy storage density, small temperature change in the heat absorption and release process, and easy process control.
And there are various materials and they are widely used.
Energy storage PCMs have the ability to change their physical state and absorb or release latent heat within a certain temperature range.
For example, taking the solid-liquid phase change, when heated to the melting point, the phase change material absorbs and stores a large amount of latent heat during the melting process.
When cooled to the freezing point, the PCM releases latent heat during the solidification process. The energy storage phase change material should have the following properties: low toxicity, appropriate phase change temperature, large latent heat of phase change, stable performance, good reversibility of phase change, small expansion and contraction rate during phase change, good thermal conductivity, low price, and easy availability of raw materials.
Energy storage phase change materials can be divided into four types according to the phase change form: solid-liquid phase change material, solid-gas phase change material, liquid-gas phase change material, and solid-solid phase change material. The latent heat of the crisis change between solid-gas phase change material and liquid-gas phase change material is large, but the large volume change, high pressure, and poor thermal conductivity limit the application scope.
The latent heat of phase change of solid-solid phase change materials is low, the phase change process is slow, and the application scope is small. Solid-liquid phase change materials have the advantages of large latent heat of phase change, wide phase change temperature and low cost, and are energy storage phase change materials with great practical value and mature technology, so energy storage phase change materials generally refer to solid-liquid phase change materials.
Energy storage phase change materials can be divided into inorganic, organic (including polymers) and composite phase change materials according to their composition. Non-organic phase change materials mainly include metals and alloys, crystal water salts, molten salts, etc., which have the advantages of large latent heat of phase change, high volumetric energy storage density and large thermal conductivity.
But there are disadvantages of easy bottom cooling and phase separation. Organic phase change materials mainly include aliphatic hydrocarbons (such as paraffin), fatty acids, alcohols, polyenols, etc.
In the state of heating, stable performance and low cost, but have the disadvantages of small thermal conductivity, low density, volatility and easy aging. Composite phase change materials mainly refer to organic and inorganic eutectic phase change materials to overcome the shortcomings of single inorganic or organic phase change materials.
The most studied are shaped phase change materials (SSPCM) and microencapsulated phase change materials (MEPCM).
Energy storage PCMs are divided into high temperature (above C250), medium temperature (250~100°C) and low temperature (below 100°C) phase change materials, high temperature phase change energy storage materials are mainly used in concentrated solar thermal power generation, industrial waste heat recovery, high temperature heat engines and other fields. Medium temperature phase change energy storage materials are mainly used in solar thermal utilization, drying and dehumidification and other fields; low temperature phase change energy storage materials have broad application prospects in the fields of building energy conservation, thermal management of electronic devices, low temperature refrigerators.
The design, preparation and strengthening of energy storage phase change materials are the core of materials research and development. In order to obtain the appropriate phase change temperature and latent heat of phase change, various phase change materials should be synthesized into multi-component mixed phase change materials according to a certain ratio.
The preparation of energy storage phase change materials mainly includes mechanical methods (loading phase change materials into containers), physical methods (mixing methods, deposition methods, etc.), chemical methods (polymer polymerization methods, sol-gel methods, etc.) and microencapsulation methods. For phase change materials with low thermal conductivity, it is necessary to add good thermal conductivity materials (metal fillers, graphite, carbon fibers, etc.).
The durability and economy of energy storage PCM are the key to its application development.
Energy storage phase change materials
With the global agreement on carbon peak and carbon neutrality, all countries have increased the construction of renewable energy. This has greatly increased the demand for energy storage devices and heat storage devices.
It has played a big role in promoting the development of energy storage technology. It provides strong policy support for the application of heat storage technology in peak shape and valley foiling and clean heating. It once again gives great motivation and confidence to the heat storage industry.
What is energy storage?
Energy storage refers to the process of storing energy in the form of fruit seeds through a medium or device and releasing it in a specific form when needed.
Among them, thermal energy storage, also known as thermal storage, is one of the important forms of energy storage, it refers to the technology of storing thermal energy in a specific medium and converting it into electrical energy or other forms of energy when needed. Thermal storage technology includes sensory thermal energy storage, phase change energy storage, and thermochemical energy storage.
What is phase change energy storage technology?
Phase change energy storage materials are the core of phase change technology. It can exchange energy with the external environment (absorb heat from the external environment or release heat from the external environment). In order to achieve the purpose of regulating the environmental temperature and utilizing energy, the phase change material absorbs heat from the solid state to the liquid state.
When the heat is released, it changes from the liquid state to the solid state. Although the temperature does not change during the melting or solidification process, the latent heat absorbed or released by the PCM is considerable. With the phase transformation of the material, the energy is stored and released accordingly.
Classification of phase change energy storage technology
Phase change energy storage materials can be divided into several categories: low temperature phase change materials, medium temperature phase change materials, and microencapsulated phase change materials.
Low temperature phase change materials
Low temperature PCMs are generally composed of organic materials, including paraffin, fatty acid and its derivatives, polyol, polyethylene, etc. These materials have adjustable phase change temperature points, good chemical stability and compatibility, and are widely used in the field of temperature control of buildings. For example, in winter, low temperature PCM can absorb excess heat in the room and release it at night, reducing energy consumption.
Medium and high temperature phase change materials
Medium and high temperature phase change materials mainly include inorganic salts, metals and alloys. They have higher phase change temperatures and are suitable for industrial heating or solar thermal collection systems.
For example, some inorganic chlorine can be used as energy storage media in solar water heaters or thermal power plants, which can store solar energy during the day and release it slowly at night.
Microencapsulated phase change materials
In addition, there are special microencapsulated phase change materials. These materials can better control the transfer and storage of heat by encapsulating phase change materials into small capsules. And they can be easily combined with other materials, which improves the application scope and effectiveness of the materials.
Applicability
Phase change energy storage technology has attracted more and more attention, especially in the fields of energy conservation, emission reduction and new energy utilization. The use of phase change materials can effectively reduce indoor temperature fluctuations, improve the comfort of air conditioning systems and reduce energy consumption. In the industrial field, phase change energy storage can be used as an important method in the field of thermal energy. Optimizing the use of thermal energy and reducing resource waste.
In the future, with the continuous development of materials science and the deepening of technological innovation, phase change energy storage devices will play an important role in more fields. From small household thermal energy storage devices to large-scale industrial thermal energy management systems, phase change energy storage technology is one of the key paths to achieve environmentally friendly and efficient energy utilization.
Let's take a look at some of the notable features of this material:
1. High energy storage density: PCM can absorb or release a lot of latent heat during the conversion process. Improve space utilization.
2. Temperature stability: The material temperature is almost constant during the phase transition, which is a great advantage in environments that require precise temperature control.
3. Reusability: PCM energy storage materials can be recycled thousands of times without losing efficiency. This makes it an excellent product in terms of longevity and reliability.
4. Variety of Material Choices: From organic materials to inorganic salts to bio-based materials, PCMs come in a variety of types, allowing them to be customized and optimized to meet a variety of needs.
5. Energy Savings: By efficiently utilizing waste heat generated from everyday activities or regulating the temperature of buildings and roads, PCMs help reduce energy consumption and greenhouse gas emissions.
6. Renewable Energy Compatibility: PCMs can complement intermittent and unstable problems and achieve a smooth energy supply by utilizing renewable energy technologies such as solar and wind energy.
7. Specialized Innovation Applications: In cooling electronics, solar water heating systems, heating, ventilation and air conditioning (HVAC) systems, PCMs open up new applications and possibilities.
What is “Phase-Changing Energy Storage Technology”?
Not only do these materials have many interesting properties, they also play a vital role in promoting energy efficiency and facilitating the integration of renewable energy. With the continuous development of technology, phase change energy storage materials will undoubtedly play a leading role in the future energy environment. Adding more sustainable applications to our lives.
In the pursuit of sustainable and eco-friendly energy solutions, biophase change energy storage materials have attracted the wide attention of the scientific and technological community due to their unique advantages.
What is biophase change energy storage material?
In simple terms, it is a "fused eutex mixed fatty alcohol" prepared by a scientific method extracted from animal fat and vegetable fat. It has good energy storage properties.
The most attractive point of this material is its suitable phase transition temperature and high potential heat capacity. It can store and release a large amount of energy within a certain temperature range. In addition, they are subcooling, non-toxic, non-corrosive, and have excellent molecular and thermal stability.
What do these characteristics mean?
In the design of energy-efficient buildings and the development of environmentally friendly heating and cooling systems, biophase change energy storage materials are sure to be an innovative material. They offer an innovative alternative to traditional energy use.
With the development of science and technology and the improvement of environmental awareness, it is certain that these materials will be used more and more in our daily lives. For example, they will show their unique value in temperature-regulating clothing, food transportation, solar power generation and other fields.
Finally, biological phase change energy storage materials are not just science and technology products.
Biological phase change energy is an important force energy that conveys the concept of environmental friendliness and promotes energy conversion and upgrading, and it is expected to open more interesting chapters for the future.