Of Mgo Ceramic-based High-temperature Phase Change Thermal Storage Materials, Preparation And Performance

With the rapid increase of population and the improvement of people's standard of living, the consumption of energy is more and more. How to make full use of discontinuous and unstable thermal energy using heat storage technology in processes of chemical industry production and industry has been an important environment technology which can enhance energy using efficiency.Heat storage materials contain sensible heat storage material latent heat storage material chemical reaction heat storage material and composite heat storage material. The technology of heat storage can be used to solve the contradictory of unbalance between energy's supply and demand in time and space, and has broad application prospects in fields of solar energy's utilization, waste heat and afterheat's utilization industry and civil construction, and so on.The technology was suggested in the paper, mixing and sintering method was successfully used to make the composite phase change with MgO ceramic matrix for thermal energy storage material, at the same time, its preparation process characterization and loss weight were researched, finally the ideal ratio was chosen and thermal conductivity was calculated. Firstly, the theory of heat storage material was researched, according to thermodynamic soft ware HSC, there was basically not any chemical reaction between MgO and Na₂CO₃,or MgO and K₂CO₃; in addition, appropriate matrix material(MgO) and phase change material was assured according to their physical performances; from experimental research, the result of XRD analysis indicated that no chemical reaction occurred between matrix material and phase change material, and so this kind of material can be used in heat storage; an endothermic peak was seen obviously in DTA curve, and it was indicated that they could be used to make the heat storage material. At the same time, additive Bi₂O₃ was chosen to successfully out of mold, and pure ethanol as lubricant was chosen in order not to create influence on heat storage material.Secondly, the heat storage material was prepared and its preparation technology was researched. Its preparation proceeding as follows, first of all, phase change materials and matrix material's quality ratio of 1 to 9 2 to 8 3 to 7 and 4 to 6 were weighed respectively, at the same time, the additive was be weighed as 1 % of phase change material and matrix material, all materials were evenly blended and rubbed, and then pressured mold through powder tablet machine, secondly materials were put in the electric stove to sinter, finally, samples were carried on the examination analysis. Its research results were: according to the Archimedes Method, the density P was assured, then according to the relations among density and molding pressure and time, the ideal molding pressure(the instrument's pressure) and time were chosen as 6MPa and 15min respectively; through the result of HSC, melting points of phase change material and matrix material, the sintering temperature was 100℃; according to the preparation method and whether the molten salt had phase change, the ideal sintering system was chosen; at last, the ideal heating curve was determined.Finally, properties of materials and their loss weight were researched, what's more, the ideal ratio was chosen and their thermal conductivities were calculated. This kind of heat storage material was investigated through XRD TG-DTA TG, DSC SEM and EDS analyses, researching on heat storage material's phase composition, we drew the conclusion that phase change material and matrix material not occurred chemical reaction, in other words, the material had good chemical compatibility through the XRD analysis; the conclusion that heat storage materials had endothermic peaks by TG-DTA TG and DSC analyses was drawn; according to SEM and EDS analyses, there were better compound functions between them; the ideal quality ratio of Na₂CO₃ and MgO was 4 to 6 by average loss weight of heat storage materials and calculation of latent heat; in addition, this kind of material had greater thermal conductivity by calculation. This kind of composite latent thermal energy material not only has some advantages of sensible heat storage material and latent heat storage material, but also overcomes their disadvantages, what's more, gives an important reference on this kind of research.