氢氟烃在离子液体HMIMPF6中的扩散系数和亨利常数

摘要

氢氟烃+离子液体是一种非常有潜力的吸收式制冷循环工质对.利用压力衰减法测量了303.15～343.15 K范围内6种氢氟烃(R32、R125、R161、R143a、R1234yf、R152a)在离子液体1-已基-3-甲基咪唑六氟磷酸盐([HMIM][PF6])中的扩散系数和亨利常数.结果表明:6种氢氟烃在[HMIM][PF6]中的扩散系数和亨利常数均随着温度的升高而增大.在6种氢氟烃中,因R32在[HMIM][PF6]中具有较大的溶解度和扩散系数,所以R32+[HMIM][PF6]较适合作为吸收式制冷循环的工质对.最后,采用Arrhenius方程对6种氢氟烃在[HMIM][PF6]中的扩散系数和亨利常数进行了关联,计算结果与实验数据的平均绝对相对偏差分别小于2.5％和6.0％.%Hydrofluorocarbon + ionic liquid is a potential working pair for the absorption refrigeration cycle. A pressure decay technique was used to measure the diffusion coefficients and Henry's constants of six hydrofluorocarbons (R32, R125, R161, R143a, R1234yf and R152a) in 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF6]) in the temperature range from 303.15 K to 343.15 K. The experimental results show that the diffusion coefficients and Henry's constants of six hydrofluorocarbons in [HMIM][PF6] increase with the increasing temperature. Compared with other five hydrofluorocarbons, R32 not only exhibits higher solubility but also higher diffusivity. Therefore, R32 + [HMIM][PF6] is very suitable for the absorption refrigeration cycle. The Arrhenius equation was applied to correlate the diffusion coefficients and Henry's constants of six hydrofluorocarbons in [HMIM][PF6]. The average absolute relative deviations between the calculated results and the experimental data were less than 2.5％ and 6.0％, respectively.