Preparation Of Paraffin-Based Composite Phase Change Materials

Paraffin based phase change material has many advantages,such as high latent heat of phase change,no supercooling and phase separation,no corrosion,good chemical stability and low cost.It can be widely applied in building energy saving,industrial waste heat recovery and solar energy storage.However,the vulnerability of the paraffin based phase change energy storage materials in the phase change process limits its application in the construction industry.Therefore,the preparation of new paraffin based composite phase change materials has suitable phase transformation temperature,latent heat of phase change,decreasing the precipitation rate of phase change materials,and enhancing the thermal conductivity,thermal and mechanical properties of composites,which can be of practical value.This paper changes with different ratio of solid and liquid paraffin phase change temperature and latent heat,while the use of inorganic carrier diatomite,expanded graphite,PET,EVA,EPE organic carrier of phase change material thermal stability and adsorption time of different carrier maximum adsorption amount and adsorption of the paraffin after the experiment on adsorption process of mixed paraffin;the calcination and pickling,alkylation of three kinds of methods and different modifier on inorganic carrier was modified by composite thermal stability as a benchmark comparison of different modification method and agent of carrier modification ability;with LDPE as carrier of organic inorganic carrier after paraffin adsorption by melt blending method the two coating,which due to the improved thermal stability and mechanical properties of DCP by chemical crosslinking agent;the simulation of indoor water circulation heating system The preparation of paraffin based phase change energy storage material was conducted,and its temperature control ability was observed.Experimental results show that the ratio of solid and liquid paraffin by different preparation phase transition temperature of paraffin base phase change material,increase the content of liquid paraffin by DSC test,system transformation temperature and latent heat is reduced,when the liquid paraffin ratio of 1:2,phase transition temperature and latent heat is appropriate;the use of several organic and inorganic carrier on the solid-liquid mixed wax respectively.The adsorption,the maximum adsorption capacity of organic carrier in inorganic carrier,EVA maximum adsorption percentage was 319.87%.Inorganic carrier adsorption wax mixture after strong thermal stability in organic carrier,wherein the inorganic carrier expanded graphite adsorption paraffin wax precipitation rate of 20%is the lowest,the adsorption time had no effect on the maximum carrier adsorption capacity;through calcination,the inorganic carrier acid,alkylation of three types of mixed with paraffin,as modified in different ways,the alkylation is better than calcination and acid pickling.Alkylation modification in ethylsiloxane modified the best effect,the maximum release rate was 11.3%;modified inorganic carrier adsorption paraffin wax by melt blending with LDPE on the two coating,and by adding inorganic filler,initiator DCP is added to improve the mechanical properties and thermal properties.When using/LDPE/paraffin alkylation modified expanded graphite/DCP(60/40/4.6/3)ratio for preparing shaped phase change material,the phase transition temperature of 50.3 ?,latent heat is 52.44J/g,the maximum release rate was 3.83%,the coefficient of thermal conductivity is increased to 3.10(W ·M-1·K-1),11.3MPa tensile strength and impact strength of 9.49KJ/m2,elongation of 27.67%.Excellent comprehensive performance;through the simulation of indoor plumbing heating system on the effect of temperature control of the composite phase change material,wherein the extrusion machine once by extrusion molding shaping phase change material,comprehensive comparison of solid-liquid ratio of 1:2 the best content of paraffin.When the amount of phase change material increases,the capacity of heat storage is enhanced,and the process of heating and cooling is slow in the room.The composite phase change material was prepared by melt blending method of reactor.Because the reaction time is controllable,melt blending is more perfect,and the effect of temperature control is slightly stronger than that of extrusion mechanism.