Preparation And Usability Of Multi-temperature Combined Paraffin-based Phase Change Thermal Storage Board

Energy plays an essential role in the social development.It is an important topic of using energy reasonably to improve the efficiency of energy utilization.Phase change material is a kind of material that uses latent heat to store heat and save energy.In recent years,phase change material has been widely used in energy engineering.This study breaks through the limitations of the traditional single phase change temperature phase change materials in engineering application.Different types of phase change paraffin and expanded perlite are used as phase change media and carriers to prepare paraffin based phase change heat storage materials.The chemical structure and apparent properties of paraffin based phase change thermal storage materials were determined by experimental methods,and their thermo-physical properties were analyzed by DSC and TG curves.Design builder is used to simulate the energy-saving effect of multi temperature combined paraffin based phase change heat storage plate in different cities of China.In this study,32# and 25# phase change paraffin were used for vacuum impregnation and adsorption with expanded perlite in the melting state.The phase change paraffin/expanded perlite phase change materials after adsorption of phase change paraffins were encapsulated with white emulsion glue to obtain paraffin based phase change heat storage materials.DSC results show that the adsorption of expanded perlite and the encapsulation of white latex have little effect on the phase change temperature of phase change paraffin,and the phase change enthalpy of 32 # and 25 # paraffin based phase change thermal storage materials are 121.2 k J/kg and 72.13 k J/kg respectively.The enthalpy of phase change of paraffin based phase change thermal storage materials decreased slightly,but the thermal stability of paraffin based phase change thermal storage materials after TG test was greatly improved.32#paraffin based phase change thermal energy storage materials decreased by 15.33%,25# paraffin based phase change thermal energy storage materials decreased by 11.98%.The paraffin based phase-change heat storage plate was made by cold pressing with white latex as viscosity agent.The maximum value of thermal conductivity is 0.183W/(m·K)under the premise of ensuring the coating property of white emulsion in paraffin based phase change heat storage plate.The specific heat capacity of 25# paraffin based PCRs was 2.543J/(g·K)and 32#paraffin was 2.694 J/(g·K).32# paraffin based phase change heat storage plate,25#paraffin based phase change heat storage plate and concrete structure are composed of a multi temperature combined paraffin based phase change heat storage enclosure.Through constant temperature heating,the temperature retention time of the multi temperature combined paraffin based phase change heat storage structure is about 100 min.By using the design builder software,the energy-saving performance of multi temperature combined paraffin based phase change heat storage building envelope is simulated and tested.The simulation results show that the multi temperature combined paraffin based phase change heat storage enclosure has a significant effect on building energy saving.After comparing the temperature control effect of representative cities in severe cold area,cold area,hot summer and cold winter area,it is found that the multi temperature combined paraffin based phase change heat storage enclosure structure can be applied to the climate environment of different regions in China,and has significant effect on building energy saving.