Construction And Characterization Of Polyethylene Glycol Crosslinked Castor Oil/wood Phase Change Energy Storage System

In this study,solid-solid phase change material(PCM)with polyethylene glycol(PEG)as the transformation function,this study supported castor oil chain and isocyanate as the crosslinking agent synthesis of polyethylene glycol crosslinking castor oil solid-solid phase change material(SSPCM),polyethylene glycol(PEG)and cross-linking castor oil solid-solid phase change materials for energy storage unit,with wood as matrix,using the method of vacuum impregnation was prepared by phase change energy storage(PCESW)wood composite materials.Firstly,the synthesis process conditions of polyethylene glycol crosslinked castor oil solid-solid phase change material were optimized.The effects of polyethylene glycol molecular weight and the type of crosslinking agent on the performance of SSPCM were investigated.Then,by improving the impregnation process,the properties of phase-change energy storage wood composites were optimized and improved.Finally,the thermal properties,durability,thermal conductivity and microstructure of polyethylene glycol crosslinked castor oil solid-solid phase change material and phase change energy storage wood composite were comprehensively characterized,and the feasibility of using phase change energy storage wood composite for indoor temperature regulation was investigated.The main conclusions of the study are as follows:(1)Polyethylene glycol crosslinked castor oil solid-state phase change material(SSPCM)was successfully prepared.The thermal properties of SSPCM were mainly affected by the molecular weight of polyethylene glycol.With the increase of molecular weight of polyethylene glycol,the higher enthalpy of SSPCM was,the higher phase change temperature was.The type of crosslinking agent also has a certain influence on the thermal properties of SSPCM.Compared with the benzene ring structure of isocyanate,polyethylene glycol crosslinking castor oil solid-solid phase change material prepared by straight chain isocyanate has better molecular compliance,less steric resistance and higher enthalpy.When the molecular weight of the polyethylene glycol is 1500 and the crosslinking agent is hexylene diisocyanate,the thermal properties of SSPCM are the best,the melting enthalpies and crystallization enthalpies are83.51 J/g and 88.1 J/g,respectively,and the melting and crystallization temperatures are 41.0 ? and23.3 ?.(2)Delignification can effectively improve the porosity of balsa wood,and the porosity of balsa wood after alkali treatment is as high as 95.09%,which is 8.55% higher than that of balsa wood.After vacuum impregnation,polyethylene glycol-crosslinked castor oil solid phase change material(PCESW)was combined with delignificated wood to prepare PCESW.The microstructure of PCESW showed that SSPCM was mainly filled in the wood conduit.The melting enthalpy and crystallization enthalpy of PCESW are 58.24 J/g and 51.92 J/g,respectively,and the transformation temperature is within the comfort range of human body.TG and hot and cold cycle tests show that PCESW has good thermal stability and durability.Building model test shows that phase PCESW has good heat storage function,can effectively slow down the change of temperature in space,and can be used for indoor temperature regulation..(3)Phase change energy storage wood composite(PEG-PCESW)was prepared by impregnation with polyethylene glycol and then impregnation with SSPCM.This method can effectively improve the thermal properties of phase change energy storage wood.After vacuum impregnation,the melting and crystallization enthalpies of PCESW were increased to 88.13 J/g and 90.1 J/g,respectively,which were increased by 51.32% and 73.53% compared with that of SSPCM impregnation,respectively.Meanwhile,its thermal conductivity is increased to 0.1833 W/m K,which is about 263.32% higher than that of natural wood.The leakage performance test and the cold and hot cycle test results show that the PEG-PCESW has good thermal stability and durability.The house model test shows that PEG-PCESW has excellent heat storage function.In the process of rising and cooling,there will be a flat platform with temperature changes lasting up to 47 min,which indicates that PEG-PCESW can significantly slow down the change of space temperature.