Compressed and Saturated Liquid Densities for 18 Halogenated Organic Compounds^†

The pressure−density−temperature P(ρ,T)
behavior of 18 liquids that are potential working fluids
in
thermal machinery has been measured using a vibrating tube densimeter.
For each liquid, the data
were taken on isotherms spaced at intervals of 5 K to 10 K spanning the
temperature range 245 K to 370
K. The pressures ranged from just above the vapor pressure (or the
critical pressure) to 6500 kPa. The
results of measurements at more than 12 000 thermodynamic points are
summarized by correlating
functions. Comparison with data from other laboratories indicates
that the relative expanded uncertainty
in the measured densities is less than 0.05%, except in the critical
region. The repeatability of the
measured densities is on the order of 0.005%. For each liquid,
the P(ρ,T) data were extrapolated to
the
vapor pressure to obtain the density of the liquid at the vapor
pressure. The fluids studied (and their
designations by the refrigeration industry) were trichlorofluoromethane
(R11), chlorodifluoromethane
(R22), 1,1-dichloro-2,2,2-trifluoroethane (R123),
1,2-dichloro-1,2,2-trifluoroethane (R123a),
1-chloro-1,2,2,2-tetrafluoroethane (R124), 1,1,2,2-tetrafluoroethane (R134),
1,1,1,2-tetrafluoroethane (R134a), 1,1-dichloro-1-fluoroethane (R141b), 1,1,1-trifluoroethane (R143),
1,1,2-trifluoroethane (R143a), pentafluorodimethyl
ether (E125), 1,1-difluoroethane (R152a), octafluoropropane (R218),
1,1,1,2,3,3,3-heptafluoropropane
(R227ea), 2-(difluoromethoxy)-1,1,1-trifluoroethane (E245),
1,1,1,2,2-pentafluoropropane (R245cb), 1,1,1,3,3-pentafluoropropane (R245fa), and propane (R290).

本研究采用振动管密度计，测定了18种可作为热力机械潜在工质的液体的压力-密度-温度（P(ρ,T)）特性。针对每种液体，实验均在245 K至370 K的温度区间内开展，等温线间隔为5 K至10 K；测试压力范围则从略高于蒸气压（或临界压力）至6500 kPa。超过12000个热力学点的测量结果通过关联式进行了归纳总结。与其他实验室的公开数据对比后可知，除临界区域外，实测密度的相对扩展不确定度均小于0.05%，实测密度的重复性精度约为0.005%。针对每种液体，研究人员还将P(ρ,T)数据外推至蒸气压点，以获取该液体在蒸气压下的密度值。本次研究的工质（及其制冷行业命名编号）分别为：三氯氟甲烷（R11）、一氯二氟甲烷（R22）、1,1-二氯-2,2,2-三氟乙烷（R123）、1,2-二氯-1,2,2-三氟乙烷（R123a）、1-氯-1,2,2,2-四氟乙烷（R124）、1,1,2,2-四氟乙烷（R134）、1,1,1,2-四氟乙烷（R134a）、1,1-二氯-1-氟乙烷（R141b）、1,1,1-三氟乙烷（R143）、1,1,2-三氟乙烷（R143a）、五氟二甲醚（E125）、1,1-二氟乙烷（R152a）、八氟丙烷（R218）、1,1,1,2,3,3,3-七氟丙烷（R227ea）、2-(二氟甲氧基)-1,1,1-三氟乙烷（E245）、1,1,1,2,2-五氟丙烷（R245cb）、1,1,1,3,3-五氟丙烷（R245fa）以及丙烷（R290）。