Mixture optimization for mixed gas Joule-Thomson cycle

Cryogenic Engineering Conference 2017

材料科学;物理学

Detlor, J.^1 ; Pfotenhauer, J.^1 ; Nellis, G.^1

University of Wisconsin-Madison, Department of Mechanical Engineering Madison, WI

53706, United States^1

关键词: Computational tools;    Experimental investigations;    Mixed-gas joule-thomson;    Mixture compositions;    Operating parameters;    Optimization modeling;    Supply temperatures;    Three-component mixtures;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012045/pdf
DOI  :  10.1088/1757-899X/278/1/012045

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

An appropriate gas mixture can provide lower temperatures and higher cooling power when used in a Joule-Thomson (JT) cycle than is possible with a pure fluid. However, selecting gas mixtures to meet specific cooling loads and cycle parameters is a challenging design problem. This study focuses on the development of a computational tool to optimize gas mixture compositions for specific operating parameters. This study expands on prior research by exploring higher heat rejection temperatures and lower pressure ratios. A mixture optimization model has been developed which determines an optimal three-component mixture based on the analysis of the maximum value of the minimum value of isothermal enthalpy change, ΔhT, that occurs over the temperature range. This allows optimal mixture compositions to be determined for a mixed gas JT system with load temperatures down to 110 K and supply temperatures above room temperature for pressure ratios as small as 3:1. The mixture optimization model has been paired with a separate evaluation of the percent of the heat exchanger that exists in a two-phase range in order to begin the process of selecting a mixture for experimental investigation.