以热力学计算和差热分析(DTA)实验测试相结合的方法确定了月桂酸(LA)和棕榈酸(PA)的二元系低共熔物组成和相变温度;以焦粉为载体材料,制备了LA-PA/焦粉复合相变储能材料(LA-PA/焦粉CPCM)。用红外(FT-IR)、DTA、导热系数测定和储/放热循环实验测试研究了CPCM的结构和储热性能。结果表明:LA-PA低共熔物与焦粉具有良好的化学相容性;CPCM的相变温度为35.4℃,相变焓为105.6J/g;CPCM的导热性能[0.411W/(m·k)]相较于LA-PA[0.210W/(m·k)]提高了95.7%;经过800次的储/放热循环后,CPCM的相变温度和相变焓变化都不大,表现出较好的储热稳定性,具有实际应用价值。
The phase change temperature and eutectic composition of lauric acid/palmitic acid(LA-PA) system was tested by thermodynamic calculation and DTA experiment.LA-PA/coke powder composite phase change material(CPCM )was prepared.The structure and thermal properties of CPCM were studied using infrared (FT-IR),differential thermal analysis (DTA),thermal conductivity measurement,and storage/exothermic cycle test.The FT-IR results shown that the LA-PA eutectic mixture had good chemical compatibility with coke powder.The phase change temperature of CPCM was 35.4℃,and the phase change enthalpy wass 105.6J/g.The thermal conductivity of CPCM[0.411W/(m·k)] was 95.7% higher than LA-PA [0.210W/(m·k)].After 800 heat storage/release cycles,the phase change temperature and phase change enthalpy of CPCM had litter change,showing good heat storage stability,which was expected to be applied in practical projects.
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