Research On Preparation And Properties Of Phase Change Materials And Energy Storage Concrete

The whole world needs energy more and more with the rapid development of global industry, and the energy consume is increasing continuously. However, the energy in the earth is limited. The contradiction which energy demand cannot be satisfied by energy supply is increasingly evident. It has arouse general interest that how to solve the contradiction. This contradiction can be relieved by energy storage which is a new technology of improving the energy efficiency. Redundant energy is saved by some medium and is released when needed. Phase change materials are working with absorbing or releasing a large of heat, and keeping the same temperature in the phase change process. So it provides a theoretical basis for the application of energy storage technology.In this paper,Paraffin,Octadecane,Hexadecane,Butyl Stearate, Decanoic acid and Lauric acid were used as phase change materials. Mixing tests were carried out in these phase change materials. The research showed that the Paraffin/Butyl Stearate combination and the Decanoic acid/Lauric acid combination which were used as the best combinations were determined by observed miscribility of materials, cooling curve analysis and differential scanning calorimeter analysis. The best ratio of the Paraffin/Butyl Stearate system was Paraffin:Butyl Stearate=40%:60%, and the phase change temperature was 25.09℃and the latent heat was 112.59J/g. The best ratio of the Decanoic acid/Lauric acid system was Decanoic acid:Lauric acid=50%:50%, and the phase change temperature was 25.24℃and the latent heat was 109.7J/g.Ultra-light ceramsites selected as the base material was inorganic porous material. The compound phase change materials were sucked in ultra-light ceramsites by the mean of vacuum adsorption, and the quality of the adsorption of compound phase change materials could reach 50%. Measured by DSC, the phase change temperature and latent heat of phase change materials after sucked in ceramsites were increased slightly. The phase change energy storage ceramists were prepared through epoxy resin and modified alkali-activated slag cementitious materias used on the surface of the ceramsites. The problem that phase change materials leaked from the surface of ceramsites was solved effectively. The thermal properties and stability of phase change energy storage ceramists were tested. The research showed that the phase change temperature and latent heat of the two kinds of phase change materials were slightly higher than that before adsorption. The surfaces of all the phase change energy storage ceramsites were intact after 100 cycles of phase change, and the loss rate of the mass of phase change materials were below 5%. Phase change energy storage concrete was prepared with phase change ceramsites. The test results showed that phase change energy storage concrete prepared with ceramsites coated by epoxy resin appeared large cracks, but phase change energy storage concrete prepared with ceramsites coated by modified alkali-activated slag had good compatibility. The compressive strength of the phase change energy storage concrete was slightly lower than the general ceramsite concrete. However, the thermal properties of the phase change energy storage concrete were superior to general ceramsite concrete. The effect of energy storage of the concrete with Paraffin and Butyl Stearate phase change materials was better than the concrete with decanoic acid and lauric acid phase change materials.