"Method for producing phase-change heat storage microcapsule powder"
Manufacturing process
1. Calcium carbide slag
2. Melting
3. Na2CO3 + slag (calcium carbide slag)
4. Mix
5. Polyvinyl alcohol dissolution and core mixing
6. Pneumatic compression
7. Sintering: In order to make non-surface wide particles such as powders become denser agglomerates, the density, porosity, and pore size distribution of the material can be adjusted through the process of applying temperature and pressure and the sintering process to ultimately achieve the desired physical properties.
8. Phase change microcapsule powder
In order to avoid the many shortcomings of composite phase change heat storage technology, reasonable heat storage technology and phase change heat storage technology, composite sensory heat storage and composite phase change heat storage materials have become a hot topic at home and abroad in recent years, but traditional skeleton materials use natural minerals or their by-products.
Large-scale mining or processing damages the local ecological environment and consumes a large amount of fossil energy. In order to reduce the impact of the above problems on the environment, solid waste can be used to prepare composite screen-changing heat storage materials.
It is calcium carbide slag and acetylene. Industrial solid wastes such as polyvinyl chloride generated in the production process, my country produces more than 50 million tons per year, and the use of calcium carbide slag in the cement industry is saturated. A large amount of calcium carbide slag is piled up in the open air. It is necessary to seriously damage the regional ecosystem and explore new ways to utilize resources.
In order to absorb industrial solid waste calcium carbide slag on a large scale and prepare low-carbon and low-cost composite screen conversion heat storage materials, the Department of Bioengineering and Architecture of Ruishi University of Chemical Technology proposed to use carbcium carbide slagas the skeleton material to prepare Na2CO3/carbide composite parchange starbide slagas the material starpare na2CO3 and methering coding carbylessing carbistering coleatering na2CO3. Taking into account the modification, surface solution salt leakage and heat storage density, although the heat storage density of the NC4 sample is the largest among the three composite interface change heat storage materials, it is believed that the mass ratio of the composite stage change heat storage material to the sample NC5 is the best ratio. After that, our team analyzed the macroscopic morphology. Heat storage performance, mechanical properties of composite screen change heat storage materials, microscopic morphology, cyclic stability and compatibility of material components, and mainly drew the following conclusions. :
1. The calcium carbide slag component has good compatibility with Na2CO3. The Na2CO3/calcium carbide slag composite can replace the traditional natural skeleton material to synthesize heat storage materials, and through the large-scale resource recycling of calcium carbide slag, the low-carbon and low-cost composition of the composite screen conversion heat storage material can be realized.
2. 52.5% calcium carbide slag and 47.5% phase change material Na2CO3/composite material can be used to prepare phase change heat storage materials with excellent performance. No fluctuation, no leakage, the highest heat storage density is 993J/g, the compression strength is 22.02MPa, and the heat storage performance of the thermal conductive sample NC5 of 0.62W/(m•K) remains stable within 100~900℃.
3. The thickness of the film layer determines the intergranular force of the skeleton material and the compressive strength of the composite interface change heat storage material. And the composite screen change heat storage material has the best mechanical properties when prepared with the maximum mass secretion.
4. The thermal conductivity of the skeleton material particles is the main factor affecting the heat transfer performance of the composite screen change heat storage material. And improve the stage change material to penetrate into the skeleton material structure, enhance the thermal conductivity of the absorbed skeleton material particles, thereby improving the heat transfer performance of the composite screen change heat storage material. All the same.
The energy storage stage change material has the advantages of high energy storage density, small temperature change during heat absorption and release process, and easy process control.
And there are many types of materials and wide applications.
Energy storage PCM has the ability to change physical state and absorb or release latent heat within a certain temperature range.
For example, take a solid-liquid phase change. When heated to the melting point, the phase-changed material absorbs and stores a large amount of latent heat during the melting process.
When cooled to the cooling point, PCM releases latent heat during solidification. Energy storage phase change materials should have the following characteristics: low toxicity, suitable phase change temperature, large phase change latent heat, stable performance, good phase change regeneration, low expansion and contraction rate during phase change, good thermal conductivity, low cost, and easy access to raw materials.
Energy storage phase change materials can be divided into four types according to the phase change form. Solid-liquid phase change materials, solid-gas phase change materials, liquid-gas phase change materials and solid-gas phase change materials. The latent heat of the crisis change between solid-gas phase change materials and liquid-gas phase change materials is large, but the volume change is large, the high pressure and thermal conductivity are poor, and the application range is limited.
Solid-solid phase change materials have low latent heat of phase change, slow phase change process and small application range. Solid-liquid phase change materials have the advantage of large latent heat of phase change. They are energy storage phase change materials with large phase change temperature, low cost, great practical value and mature technology. Therefore, 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 phase change latent heat, high volume energy storage density, and high thermal conductivity.
But its disadvantage is that it is easy to cool down and separate. Organic materials mainly include hydrocarbons (paraffin, etc.), fatty acids, alcohols, polyols, etc.
In the heated state, the performance is stable and the cost is low, but the disadvantages are low thermal conductivity, low density, easy volatility and easy aging. The composite screen changing material mainly refers to the organic and inorganic Utex screen changing materials to overcome the shortcomings of single inorganic or organic screen changing materials.
The most studied are shape phase change materials (SSPCM) and microencapsulated phase change materials (MEPCM).
Energy storage PCM is divided into high temperature (above C250), medium temperature (250~100℃) and low temperature (below 100℃) phase change materials. High temperature phase change energy storage materials are mainly used in concentrated solar power generation, industrial waste heat recovery, high temperature thermal 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 field of building energy conservation, thermal management of electronic equipment, and low temperature refrigerators.
The design, preparation and strengthening of energy storage phase change materials are the key to material research and development. In order to obtain the appropriate phase change temperature and latent heat of phase change, it is necessary to synthesize a multi-component mixed phase change material by combining various phase change materials in a certain proportion.
The preparation of energy storage phase change materials mainly includes mechanical method (putting phase change materials into containers), physical method (mixing method, deposition method, etc.), chemical method (polymer polymerization method, sol method, etc.), and microencapsulation method. For thermal conductivity low-order change materials, it is necessary to add excellent thermal conductive materials (metal fillers, graphene, carbon fiber, etc.).
The durability and economy of energy storage PCM are the key to its application development.
Transducer material
The global consensus on carbon peak and carbon neutrality has led all countries to increase renewable energy construction, which has greatly increased the demand for energy storage and heat storage devices.
It has greatly promoted the development of energy storage technology and provided strong policy support for the application of heat storage technology in peak load shaving and valley filling and clean heating, which has once again brought great momentum and confidence to the heat storage industry.
What is an energy storage device?
Energy storage refers to the process of storing energy in the form of seeds through a medium or device and releasing it in some form when necessary.
It is also called thermal energy storage and thermal energy storage. It 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 necessary. Thermal energy storage technology is sensory thermal energy storage, phase change energy storage, and thermochemical energy storage.
What is phase-shift energy storage technology?
Phase change energy storage materials are the core of phase change technology. They can exchange energy with the external environment (absorb heat from the outer ring or release heat from the external environment). In order to achieve the purpose of regulating the ambient temperature and utilizing energy, the phase change material absorbs heat from solid to liquid.
When heat is released, it changes from a liquid to a solid state. Although the temperature does not change during the recording or solidification process, the latent heat absorbed or released by the PCM is considerable. As the substance gradually transforms, energy is stored and released accordingly.
Cascade energy storage technology classification
Phase change energy storage materials can be divided into several categories: low temperature phase change materials, medium and high temperature phase change materials and microencapsulated phase change materials.
Low temperature phase change materials
Low-temperature PCM is generally composed of organic substances such as paraffin, fatty acids and their hydroxyl groups, polyols, polyethylene, etc. This material has a controllable stage-changing temperature point, good chemical stability and compatibility, and is widely used in the field of temperature control in buildings. For example, in winter, low-temperature PCM can absorb excess heat in the room and release it at night, thereby reducing energy consumption.
Medium and high temperature phase change materials
Medium and high temperature phase change substances mainly include inorganic salts, metals and alloys, etc. With a high phase change temperature, it is suitable for industrial heating or solar energy collection systems.
For example, some inorganic chlorine can be used as an energy storage medium in solar heaters or thermal power plants, storing solar energy during the day and releasing it slowly at night.
Microencapsulated gait-changing substances
In addition, there is a special microencapsulated gait-changing substance. This substance can embed the phase-changing substance in small capsules, thereby better controlling the transfer and storage of heat. And it is easy to combine with other materials, which improves the application range and effect of the material.
applicability
Phase change energy storage technology has attracted more and more attention, especially in energy conservation, emission reduction and new energy utilization. The use of phase change materials can effectively reduce room 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 way in the field of thermal energy. Optimize thermal energy utilization and reduce resource waste.
In the future, with the continuous progress of materials science and the deepening of technological innovation, phased conversion energy storage devices will play an important role in more fields. In small household thermal energy storage devices, large-scale industrial thermal energy management systems and phased conversion energy storage technology are one of the key paths to achieve green and efficient energy utilization.
If we observe several striking features of this material
1. High energy storage density: PCM can absorb or release a large amount of latent heat during the conversion process. Improve space utilization.
2. Temperature stability: During the phase change process, the material temperature remains almost unchanged, 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. It is an excellent product for longevity and reliability.
4. Different material options: From organic materials to inorganic salts to bio-based materials, PCMs are of various types. In order to be user-defined and optimized for different needs.
5. Energy saving: By effectively utilizing waste heat generated from daily activities or controlling the temperature of buildings and roads, PCM helps to reduce energy consumption and greenhouse gas emissions.
6. Close to new energy: PCM uses renewable energy technologies such as solar energy and wind energy to make up for intermittent and unstable problems and ensure smooth energy supply.
7. Professional innovative applications: Cooling electronics, solar water heating systems, heating, ventilation and air conditioning (HVAC) systems, PCM as new application areas and possibilities.
What is "phase-change energy storage technology"?
These materials not only have many interesting properties, but also play an important role in promoting energy efficiency and promoting the integration of renewable energy. As technology continues to develop, energy storage materials with stage changes will undoubtedly play a leading role in the future energy environment. Add more sustainable applications in our lives.