Study for the vapor-liquid critical point of ternary mixture composed of next generation refrigerants

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03982
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Kyushu University
• Principal Investigator: HIGASHI Yukihiro 九州大学, カーボンニュートラル・エネルギー国際研究所, 教授 (90183095)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 気液臨界点 / 3成分系混合冷媒 / 低GWP冷媒

Outline of Final Research Achievements

There is an urgent need to search for new substances to replace fluorocarbon refrigerants, which are thought to be the causative agents of ozone layer depletion and global warming. However, I found it was difficult to search for candidates from a single substance based on the results of our previous research. Therefore, ternary or multi-component mixtures are considered as an expecting candidate. The thermodynamic properties that form the basis of the development of three-component refrigerants are still unknown, and even reliable estimation methods have not been completed. In this study, the critical constants, which are the most fundamental thermophysical properties, were obtained from experiments for three kinds of ternary refrigerant mixtures (R32 + R1234yf + CO2, R32 + R1234yf + R290, R32 + R1234yf + R1123) with high accuracy. Then, the conventional estimation methods were compared with the present results.

Free Research Field

熱物性

Academic Significance and Societal Importance of the Research Achievements

流体の気液臨界点は、状態方程式や各種相関式の構築や、対応状態原理に基づく熱物性値の推算に利用されている重要な熱物性値情報である。混合物の真の臨界点を実験から求めることは容易ではなく、実際に測定値の報告も非常に少ない。そのため、混合物の真の臨界点の推算に関する研究も進展していないのが現状である。
本研究では、ほとんど実測値がない3成分系混合冷媒の臨界定数（臨界温度、臨界圧力、臨界密度）を、メニスカスの消滅と臨界タンパク光の観察から実験的に決定した。そして、得られた実験データに基づいて、臨界点の推算法について比較検討を行い、新たな推算法の開発に重要となる知見を見つけることができた。