Abstract:

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.

Key words: pressure decay technique, diffusion coefficient, Henry's constant, ionic liquid, hydrofluorocarbon

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（钅翁）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%。

关键词: 压力衰减法, 扩散系数, 亨利常数, 离子液体, 氢氟烃