Phase Transition Of The Design And Development Of The Accumulator

Since the world energy crisis in the the 1970s, the basis for the application of phase change energy storage technology research developed rapidly and constantly, and has become one of the most important technologies in the fields such as the development of new energy, coordination of energy supply and demand in the time and intensity mismatches, and improving energy utilization technologies. As China has a growing number of areas in the new electricity tariff system, phase change energy storage technologies can play a role in changing apex fill valley so that can ease the electricity load, and result huge economic benefits. In the study of phase change energy storage technology, the development of phase change materials is of concern to most people. Solid-liquid phase change materials have an access to a wide range of national scientists for the advantages of high storage density, similar process in thermostatic function, small changes in the size, easy control of process.Solid-liquid phase change materials are of many kinds. According to the temperature change, phase change materials can be divided into high temperature materials, normal temperature, and low temperature materials. Normal and low temperature materials are mainly inorganic salt hydrates, organic, macromolecular, which are commonly used as energy storage materials. In recent years, the research and development of these materials are very active areas and with widespread attention.Solid-liquid phase change energy storage technology needed to study many issues, mainly attributed to two broad categories. One is the research of the nature of materials, including the thermal property of materials, the basis of heat transfer in phase changing, and the material life and stability. These relate to the thermal property measured, the volume of technical analysis and thermal analysis and thermal chemical physics field. Another is that the application of phase change materials, including materials and packaging compatibility of their thermal devices, the designs of thermal storage devices, methods to enhance the capacity of phase change materials' heat conduction, enhanced heat transfer of thermal storage devices and the operation of state control, etc.In this article, stearic acid, paraffin wax, 6 hydration magnesium chloride, 12 hydration alum, aluminum chloride and potassium chloride mixture were chosen to be tested from the current multiple of normal and low temperature phase changematerials. Then some theoretical and experimental researchs were taken to test their phase-changing temperature, latent heat, specific heat, and their relative performance in the phase change process, through DSC testing, T-history method and melting-cooling circle. The stearic acid and paraffin wax have high latent heat and maintain good performances in the melting-cooling circles, while they have low energy storage density and heat conductivity;6 hydration magnesium chloride and 12 hydration alum have higher energy storage density, but their applications are restricted for the supercooling and phase separation;aluminum chloride & potassium mixture is eliminated for the nature of the materials and mixed proportion.After the tests, stearic acid, as a better phase change material, was chosen to be used in the structural design of electric water heaters. Compared with the mainstream market, the water heater designed by this program has such advantages: small volume, low cost, low operational costs, security advantages and so on. It also can ease the grid load and has great potential for development.