Study on the Vapor-Liquid Equilibria using a Composition Analysis Technique from Ultrasonic speed for Hydrofluorocarbon Mixtures.

使用超声波速度成分分析技术研究氢氟碳混合物的汽液平衡。

• 批准号: 09555230
• 负责人: TAKAGI Toshiharu
• 金额: $ 3.01万
• 依托单位: Kyoto Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09555230/
• 关键词: Vapor-liquid equilibria; Dew and bubble point; Alternative refrigerants; Binary mixtures; Ultrasonic speed analysis method; 二成分混合系; 代替えフロン; 非塩素フロン; フロン混合系; 音速濃度分析

The vapor-liquid equilibria for fluid mixture is important thermodynamic properties to measure the characteristics of system and to design the process. The studies on the vapor-liquid equilibria for several mixtures have been reported elsewhere. The composition of systems in these studies has been observed by analyzing on the gas clomatogram. However, this technique was very difficult to measure the vapor-liquid equilibria at very lower or higher temperatures than the room temperature. Because the different of conditions (pressure and/or temperature) between the sample chamber and the injection of gas-chlomatograph give rise to irregularity to the composition determination for systems, especially in the cases of those having higher bubble or dew points pressures.The ultrasonic speeds in fluid can be measured accurately at critical conditions. In the previous works. Takagi reported the vapor pressure and bubble point pressure for same hydrofluorocarbons measured by an acoustic absorptio … More n technique in the wide temperature ranges. In this work. the new apparatus for measurement the vapor-liquid equilibria was constructed. The method used here was the composition analysis technique from the ultrasonic speed in the hydrofluorocarbon mixtures. In the high pressure equilibrium cell made stainless steel, SUS3 16, two chambers to measure the ultrasonic speed in gas (upper side) and liquid (lower side) phases were set up in parallel. Also this vessel have two optical windows to observe the condition of cell inside.In order to confirm the reliability of new apparatus, the VLE for (1-x)HFC32 + x HFCI34a. which have the large difference in the vapor pressures between both pure substances. were measured at several temperatures. from 243.15 to 333.15 K, and compositions. x. The uncertainties of VLE obtained are within 2.5% for the bubble point pressure and 7% for the dew point pressure by comparison with the references data. For (1-x) HFC32 + x HFC 125, the vapor pressure difference between the pure substances was small. the VLE were also measured at same conditions described above. The experimental errors for this system. which have an azeotrope. were a larger than those for former system, especially for dew point pressure. Less

流体混合物的汽液平衡是测量系统特性和设计工艺的重要热力学性质。对几种混合物汽液平衡的研究已在其他地方报道。通过气相色谱仪分析，观察了这些研究体系的组成。然而，这种技术很难在比室温更低或更高的温度下测量气液平衡。由于样品室和气相色谱仪进样之间的条件（压力和/或温度）不同，导致系统成分测定的不均匀性，特别是在那些具有较高气泡或露点压力的情况下。在临界条件下，可以精确测量流体中的超声波速度。在之前的作品中。Takagi报告了用声波吸收技术在宽温度范围内测量的相同氢氟碳化合物的蒸汽压和泡点压力。在这项工作中。建立了一种新的气液平衡测量装置。本文采用的方法是从氢氟碳化物混合物的超声波速度中提取成分分析技术。在不锈钢sus316制成的高压平衡池中，平行设置了测量气相（上）和液相（下）超声速度的两个腔室。该容器有两个光学窗口，可以观察细胞内部的情况。为了确认新装置的可靠性，VLE为（1-x）HFC32 + x HFCI34a。两种纯物质的蒸汽压差别很大。是在不同温度下测量的。从243.15到333.15 K，以及成分。x.与参考数据相比，得到的汽泡点压力不确定度在2.5%以内，露点压力不确定度在7%以内。对于（1-x） HFC32 + x hfc125，纯物质之间的蒸汽压差很小。在上述相同条件下也测量了VLE。该系统的实验误差。它们有一个共沸体。对露点压力的影响较大。少

项目成果

Takagi, T. ; Sakura, T. ; Tsuji. T. ; Hongo, M.: "Bubble point pressure for binary mixtures of difluoromethane with pentafluoroethane and 1, 1, 2-tetrafluoroethane" Fluid Phase Equilibria. (印刷中).

Takagi, T.；Sakura, T.；Hongo, M.：“二氟甲烷与五氟乙烷和 1, 1, 2-四氟乙烷的二元混合物的泡点压力”（正在出版）。

Takagi,T.: "Ultrasonic speeds in compressed liquid and vapor pressure for pentafluoroethane" J.Chem.Eng.Data. 41. 1325-1328 (1997)

Takagi,T.：“压缩液体中的超声波速度和五氟乙烷的蒸气压”J.Chem.Eng.Data。

TAKAGI,T., Sakura, T., Tsuji, T., Hongo, M.: "Bubble point pressure for bunary mixtutes of difluoromethane With pentafluoroethane and 1,1,1,2-tetrafluoroethane" Pluid Phase Equilibria. (to be contribute).

TAKAGI,T.、Sakura, T.、Tsuji, T.、Hongo, M.：“二氟甲烷与五氟乙烷和 1,1,1,2-四氟乙烷的二元混合物的泡点压力”液相平衡。

Takagi,T.;Sakura,T.;Tsuji,T.;Hongo,M.: "Bubble point pressure for binary mixtures of difluoromethane with pentafluoroethane and 1,1,2-tetrafluoroethane" Fluid Phase Equilibria. (印刷中).

Takagi, T.；Sakura, T.；Tsuji, T.；Hongo, M.：“二氟甲烷与五氟乙烷和 1,1,2-四氟乙烷的二元混合物的泡点压力”（正在出版）。