氢氟烃(HFC)二元混合物表面张力测量

Surface tension measurements of binary hydrofluorocarbon mixtures

氢氟烃(HFC)混合物是长期性的制冷剂替代物,其表面张力数据对于制冷空调设备的设计计算必不可少。对HFC-32/125,HFC-32/134a,HFC-32/227ea,HFC-143a/227ea和HFC-143a/134a5种二元混合制冷剂的表面张力进行了实验研究,用毛细管内液面上升高差法(DCRM)精确测量了其253～333K的表面张力数据,温度和表面张力的最大不确定度分别为±10mK和±0.15mN.m-1。使用测量结果拟合得到了对应混合工质的表面张力关联式,并与目前已有的文献数据进行了比较。

Surface tension data for hydrofluorocarbon (HFC) mixtures, which are interim and long-term alternatives to fluorocarbons, is necessary for proper design of air conditioners and refrigeration equipment. The surface tensions of HFC-32/125, HFC-32/134a, HFC-32/227ea, HFC-143a/227ea, and HFC-143a/ 134a were measured from 253 K to 333 K using the differential capillary rise method (DCRM) for vapor-liquid equilibrium conditions. The temperature and surface tension uncertainties were estimated to be within ±10 mK and ±0.15 mN·m^-1. The experimental data and correlations for the corresponding pure refrigerants were used to develop a van der Waals-type correlation to represent the surface tension of the five binary mixtures. The experimental results and correlation compare well with available data in the literature.