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SⅡ型R134a制冷剂笼状水合物是理想的蓄冷介质之一。基于分子动力学(MD)方法,建立晶体结构模型,在NPT系综下运算,通过观察最终构象,分析计算体系中粒子的均方位移(MSD)和径向分布函数(RDF),从微观上揭示了小分子和温度对SⅡ型水合物晶体结构稳定性的影响。结果表明:小分子对小晶穴(512)占有率从0.25变化到1.00,占有率为0.25和0.50时,水合物晶体结构分解严重,体系中分子混乱,晶体结构难以稳定存在,占有率在0.75以上时,水合物晶体结构清晰有序,能够稳定存在;当体系温度由260K增大到290K时,水合物结构的稳定性逐渐降低,在280K时晶体结构出现扭曲变形,此时有部分水合物开始分解。
S Ⅱ type R134a refrigerant clathrate hydrate is one of the ideal storage medium. Based on the molecular dynamics (MD) method, a crystal structure model is established. Under the NPT ensemble, the mean square displacement (MSD) and radial distribution function (RDF) of the particles in the system are calculated and analyzed by observing the final conformation. The effects of small molecules and temperature on the crystal structure stability of SⅡ hydrate crystals were revealed. The results showed that the crystal structure of hydrate decomposed seriously when the occupancy of small crystal (512) changed from 0.25 to 1.00 and its share was 0.25 and 0.50. The molecular structure was confused and the crystal structure was difficult to exist stably with the share of 0.75 , The crystal structure of hydrate is clear and orderly and can exist stably. When the system temperature is increased from 260K to 290K, the stability of the hydrate structure decreases gradually. At 280K, the crystal structure is distorted. At this time, some hydrates Began to break down.