Rowane Aaron J, Perkins Richard A
Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, United States.
J Chem Eng Data. 2022;67(6). doi: 10.1021/acs.jced.2c00037.
Speed of sound data measured using a dual-path pulse-echo instrument are reported for binary mixtures of 1,1,1,2-tetrafluoroethane (R-134a), 2,3,3,3-tetrafluoropropene (R-1234yf), and -1,3,3,3-tetrafluoropropene (R-1234ze(E)). For each binary mixture, the speed of sound is studied at two compositions of approximately (0.33/0.67) and (0.67/0.33) mole fraction. The conditions covered in this study range in temperature from 230 to 345 K and from pressures slightly above the bubble curve up to a maximum pressure of 51 MPa. However, to avoid potential polymerization reactions, data for mixtures containing R-1234yf are limited to a maximum pressure of 12 MPa at temperatures below 295 K and 8 MPa at temperatures above 295 K. The mean uncertainty of the measured speed of sound is less than 0.1%, where relative combined expanded uncertainties at individual state points range from 0.04 to 0.4% of the measured speed of sound value. The greatest combined expanded uncertainties are encountered as the state point approaches the mixture critical region where weakened echo signals and lower speed of sound values are observed. The reported data are compared to available REFPROP mixture models, which are not adjusted using the data reported here, with average absolute deviations ranging from 0.27 to 0.75% with maximum deviations as high as 1.1%. The comparisons to the REFPROP correlations show that further adjustments to the mixture models are needed to provide a representation of the data within its experimental uncertainty.
报告了使用双路径脉冲回波仪器测量的1,1,1,2 - 四氟乙烷（R - 134a）、2,3,3,3 - 四氟丙烯（R - 1234yf）和 - 1,3,3,3 - 四氟丙烯（R - 1234ze(E)）二元混合物的声速数据。对于每种二元混合物，在摩尔分数约为(0.33/0.67)和(0.67/0.33)的两种组成下研究了声速。本研究涵盖的条件为温度范围从230至345 K，压力从略高于泡点曲线到最大压力51 MPa。然而，为避免潜在的聚合反应，含R - 1234yf混合物的数据在温度低于295 K时限于最大压力12 MPa，在温度高于295 K时限于8 MPa。测量声速的平均不确定度小于0.1%，其中各个状态点的相对合成扩展不确定度范围为测量声速值的0.04%至0.4%。当状态点接近混合物临界区域时会遇到最大的合成扩展不确定度，此时会观察到回波信号减弱和声速值降低。将报告的数据与可用的REFPROP混合物模型进行比较，这些模型未使用此处报告的数据进行调整，平均绝对偏差范围为0.27%至0.75%，最大偏差高达1.1%。与REFPROP相关性的比较表明，需要对混合物模型进行进一步调整，以便在实验不确定度范围内表示数据。
