三氟乙烷的气相音速测量与热力学性质研究

Speed-of-Sound Measurements and Ideal-Gas Heat Capacity for 1,1,1-Trifluoroethane

采用球型腔体声学共振法测量了新型制冷剂三氟乙烷 (HFC143a)的气相音速 ,得到了压力在 2 0 0～ 80 0kPa范围内 ,温度分别为 2 93 61、30 2 96、313 19和 32 3 18K时的 4条等温线共 2 8个音速数据 .根据实验数据 ,由热力学关系式得到了HFC143a的理想气体比定压热容和第二音速维里系数等热力学性质 ,同时根据现有的高精度实验数据拟合了HFC143a的理想气体比热方程 .温度、压力和气体音速测量的不确定度分别为± 14mK、2 0kPa和± 0 0 0 37% .

Speed-of-sound, ideal-gas heat capacity and the second acoustic Virial coefficient have been experimentally studied for 1, 1, 1-trifluoroethane (HFC143a), which is a new refrigerant to substitute chlorodifluoromethane (HCFC22) and/or dichlorodifluoromethane (CFC12). Twenty-eight speed-of-sound values in gaseous 1, 1, 1-trifluoroethane were measured with a spherical resonator for pressure from 200 kPa to 800 kPa along with four isotherms at 293.61, 302.96, 313.19 and 323.18 K, respectively. The ideal-gas heat capacity as well as the second acoustic Virial coefficient has been deduced from the speed-of-sound measurements. The equation of ideal-gas specific heat capacity for 1, 1, 1-trifluoroethane was also proposed, which is effective in temperature range 250-400 K. The experimental uncertainties of temperature, pressure and speed-of-sound for 1, 1, 1-trifluoroethane are estimated to be plus and minus 14 mK, 2.0 kPa and plus and minus 0.0037%, respectively.