Study On Preparation And Properties Of Phase Change Energy Storage Ceramsites

With the development of industry and the growing of energy demand,the phase change energy storage material is rapidly rising and developing in various countries.Phase change material can absorb or release a large quantity of latent heat when it changes phase from solid state to liquid state or vice versa.Phase change heat storage technology is an important technology to improve energy efficiency and protect environment,which can be used to solve the contradiction between supply and demand of heat energy.This research developed a novel composite PCM by incorporation of capric acid(CA)-hexadecanol(H)into tailings ceramsites for hydrothermal reaction through vacuum impregnation.Phase change energy storage composites were measured by means of XRD,SEM,DSC and FTIR.The main work was as follows:(1)Selection of phase change materials.The behavior and thermal properties of capric acid-myristic acid,capric acid-hexadecanol,lauric acid-myristic acid were measured by means of cooling curve analysis and DSC analysis.The results indicated that three systems can form mixtures eutectic.Compared phase change temperature and latent heat of the three eutectic mixtures and the parameters of 75%CA-25%H were the best.The melting temperature of binary eutectic mixture(75%CA-25%H)was 21.58 ? and the melting enthalpy was 180.48 J/g.(2)Preparation and alkaline hydrothermal treatment of tailings ceramsite.Two kinds of ceramsites,labeled as A and B,were prepared by using gold slag and silver slag as the main raw materials respectively.The two kinds of ceramsites were mainly composed of quartz,in addition to a small amount of calcium feldspar.After the NaOH hydrothermal reaction of 6-12 h at 120-180 ?,the new phase of P zeolite was observed in both A and B ceramsites.After the KOH hydrothermal reaction of 4-20 h at 160 ?,the new phase of phillipsite was observed in ceramsites B.With the increase of hydrothermal temperature and hydrothermal time,the intensity of XRD diffraction peaks of quartz gradually decreased,and the diffraction peak intensity of P zeolite phase or phillipsite phase increased gradually.The water absorption rate of ceramsites improved as well.The maximum water absorption rate of A and B ceramic after the NaOH hydrothermal reaction were 41%and 55%,respectively,and the maximum water absorption rate of ceramsites B after the KOH hydrothermal reaction was 44%.(3)Thermal properties of phase change energy storage ceramsites.This research developed novel composite PCM by incorporation of 75%CA-25%H into tailings ceramsite for the KOH hydrothermal reaction of 20 h at 160 °C through vacuum impregnation.The adsorption amount of untreated ceramsite was 31%and its melting temperature and the latent heat were 23.4 ? and 35,4 J/g.After the alkaline hydrothermal reaction of 20 h,the adsorption amount of ceramsite increased to 42%and its melting temperature and latent heat were 20? and 41.48 J/g.The preparation of composite PCM was just a physical combination.In the cooling test of 50-10 ?,the temperature control effect of the energy storage sample was more than the blank sample.In summary,because of the suitable phase change temperature,the high phase change enthalpy and good performance,CA-H/zeolite ceramsite applicable to the construction field.