CAJ | 학술논문

为从微观尺度探寻相变材料的热物性变化机理,本文采用分子动力学的方法,构建了由正二十二烷组成的无定形结构的相变材料体系,采用周期性边界条件以及COMPASS力场对相变材料的比热以及导热系数进行了模拟,并对纯正二十二烷进行了DSC测试.结果表明,模拟所得的相变材料热容与文献实验值的偏差是6.5%,熔点与DSC实验值的偏差是0.98%.当温度为288—318 K时,相变材料的导热系数在0.1—0.4 W·m?1·K?1范围内波动,且随着压力增大略呈下降趋势.
위종미관척도탐심상변재료적열물성변화궤리,본문채용분자동역학적방법,구건료유정이십이완조성적무정형결구적상변재료체계,채용주기성변계조건이급COMPASS력장대상변재료적비열이급도열계수진행료모의,병대순정이십이완진행료DSC측시.결과표명,모의소득적상변재료열용여문헌실험치적편차시6.5%,용점여DSC실험치적편차시0.98%.당온도위288—318 K시,상변재료적도열계수재0.1—0.4 W·m?1·K?1범위내파동,차수착압력증대략정하강추세.
The phase change material (PCM), which is based on straight-chain alkanes, has received more and more attention for thermal management. To explore the mechanism of the thermal property of PCM from the microscopic scale, the molecular model of the PCM which consists of n-dodecane with amorphous structure is established in this study. The molecular dynamics (MD) simulation is performed with periodic boundary conditions and COMPASS force field. The melting temperature of n-dodecane is also determined by differential scanning calorimeter (DSC). The results show that the deviation of the isobaric heat capacity of the n-dodecane based PCM by MD method from the perviously reported value is 6.5%. The deviation of the simulated melting temperature of the PCM from the value from the DSC analysis is 7.6%. The simulated thermal conductivity of the PCM shows a slightly decreasing trend with pressure increasing, in a range of 0.1—0.4 W·m?1·K?1.