Preparation and heat transfer properties of mannitol phase change heat storage materials
In order to improve the encapsulation effect of mannitol(Man)which is a medium temperature phase change energy storage material(PCM),carbon carrier(PC)was constructed by high temperature calcination with in situ growth of zeolite imidazolate framework(ZIF)on graphene oxide(GO)support skeleton,and then used for encapsulation of Man via impregnating method to synthesize a composite phase change material PC/Man.PC/Man obtained were characterized and analyzed by SEM,XPS,N2 adsorption-desorption and DSC,followed by evaluation on its thermal conductivity and permeability.The solidification process of heat storage materials in tubular heat exchangers was simulated by Fluent software,with the relationship among temperature,liquid rate and time further discussed.The results revealed that PC exhibited a multistage pore structure with both mesopores and macropores,with a large specific surface area(249.7 m2/g),pore volume(0.15 cm3/g)and average pore size(about 14 nm)showing strong adsorption effect on Man,thus mitigating the leakage of Man.When heated to 180℃,the PC/Man exhibited a mass loss within 30 min of 1.03%,a heat absorption enthalpy of 185.3 J/g,and a thermal conductivity of 0.8306 W/(m·K).The high thermal conductivity channel formed by PC enhanced the rapid and effective heat release of Man.The solidification heat transfer cycle of PC/Man was 40 min,showing high heat release efficiency and good thermal conductivity,which led to rapid heat exchange.
in situ growthphase change materialsmedium temperature heat storageheat transfer simulationmannitolfunctional materials
万方数据
维普
