Theoretical Prediction And Experimental Research On The Thermal Storage Performance Of Organic Composite Phase Change Materials

Energy is the foundation and motive force of the modern development.At present,the economy of all countries in the world is developing rapidly.At the same time,with the problems of energy waste and shortage,a new round of energy production and consumption revolution is ready for development.Energy crisis is driving the development of energy storage technology.As a new functional energy storage material,phase change materials have attracted the attention of many experts and scholars.Organic phase change materials become the focus of research in energy storage field,because of its cheap,good solid state,low degree of super-cooling,large latent heat of phase change,nontoxic and non corrosive,and the thermal performance is stable after repeated cycles.Three alkanes of organic phase change materials were selected including seventeen alkanes,eighteen alkanes,twenty alkanes.Through the theoretical prediction formula,phase change temperature and phase chang latent heat of the mixtures were calculated and compared with the experimental values.The purpose of this experiment is to find a formula for calculating the thermal properties of organic compound phase change materials suitable for alkane.The test is more convenient and faster than the time-consuming and tedious test.The results show that the theoretical prediction formula can be applied to the calculation of phase change temperature and latent heat of alkane composite phase change materials.Five kinds of fatty acids,including capric acid,lauric acid,palmitic acid,stearic acid,myristic acid were mixed with industrial paraffin in different proportions to make 45 kinds of binary fatty acid-industrial paraffin mixture samples.Differential scanning calorimetry(DSC)was applied to test the phase change temperature and latent heat of the samples during melting and solidification process respectively,and the degree of supercooling and stability were analyzed.The results show that the combination of fatty acids and industrial paraffin can reduce the cost of pure fatty acids.At the same time,the series of mixtures with different phase change temperature and their application range are determined in this paper.The thermal conductivity of the binary mixtures of fatty acid and the binary mixtures of industrial paraffin and fatty acid was tested by universal thermal conductivity teste(TC3000).The effects of phase change temperature,ambient temperature of the samples and cycle number on thermal conductivity were studied respectively.The results show that the thermal conductivity of the similar phase change materials is inversely proportional to the phase change temperature.When the temperature is in the non phase change region,environmental temperature has little effect on the thermal conductivity.When the temperature is in the phase change region,the thermal conductivity increases rapidly with the increase of the ambient temperature.After 500 energy storage / energy release cycles,the thermal conductivity of the phase change material has little change.