离子液体吸收式制冷工质对气液相平衡研究及其分子动力学模拟

Study on gas-liquid phase equilibrium properties of ionic liquid absorption refrigeration working pairs and their molecular dynamics simulations

为了克服传统吸收式制冷工质对的种种缺陷,离子液体型制冷工质对被视作理想替代品,得到了广泛的开发与应用。采用静态实验和分子动力学模拟两种方法,对[EMIM]BF_(4)/CH_(3)OH离子液体二元体系的气液相平衡性质展开研究。研究结果显示,[EMIM]BF_(4)/CH_(3)OH离子液体二元溶液具有良好的气液相平衡性质,实验测得饱和蒸气压比其他醇类离子液体二元溶液低约21%;模拟结果与实验值有相同的数量级和变化趋势,相对误差普遍小于8%。研究结果为离子液体制冷工质对的筛选和进一步的理论循环系统研究提供了物性数据基础,另一方面也为离子液体基础物性研究提供了一种模拟预测的新方法。

To overcome the shortcomings of traditional absorption refrigeration working pairs,ionic liquid refrigeration working pairs have been widely developed and used as ideal substitutes.Herein,the gas-liquid phase equilibrium properties of the[EMIM]BF_(4)/CH_(3)OH ionic liquid binary system were investigated using static experiments and molecular dynamics simulations.The results reveal that this binary solution shows favorable gas-liquid phase equilibrium properties,and its saturated vapor pressure is experimentally measured to be approximately 21%lower than that of other alcohol-based ionic liquid solutions.In addition,the simulation results exhibit the same order of magnitude and trend as the experimental results,and the relative errors are generally less than 8%.These findings provide physical property database for screening ionic liquid refrigeration working pairs and studying the theoretical cycle system as well as a new method for simulating and predicting the basic properties of ionic liquids.