Micro-structured heat exchanger for cryogenic mixed refrigerant cycles

Cryogenic Engineering Conference 2017

材料科学;物理学

Gomse, D.^1,2 ; Reiner, A.^1 ; Rabsch, G.^3 ; Gietzelt, T.^3 ; Brandner, J.J.^3 ; Grohmann, S.^1,2

Karlsruhe Institute of Technology, Institute of Technical Physics, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen

76344, Germany^1

Karlsruhe Institute of Technology, Institute of Technical Thermodynamics and Refrigeration, Engler-Bunte-Ring 21, Karlsruhe

76131, Germany^2

Karlsruhe Institute of Technology, Institute of Micro Process Engineering, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen

76344, Germany^3

关键词: Convective boiling;    Cryogenic mixed-refrigerants;    Entropy production;    Heat transfer area;    Hydraulic diameter;    Mixed refrigerant cycles;    Two-phase heat transfer;    Volumetric heat transfer;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/278/1/012061/pdf
DOI  :  10.1088/1757-899X/278/1/012061

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Mixed refrigerant cycles (MRCs) offer a cost- and energy-efficient cooling method for the temperature range between 80 and 200 K. The performance of MRCs is strongly influenced by entropy production in the main heat exchanger. High efficiencies thus require small temperature gradients among the fluid streams, as well as limited pressure drop and axial conduction. As temperature gradients scale with heat flux, large heat transfer areas are necessary. This is best achieved with micro-structured heat exchangers, where high volumetric heat transfer areas can be realized. The reliable design of MRC heat exchangers is challenging, since two-phase heat transfer and pressure drop in both fluid streams have to be considered simultaneously. Furthermore, only few data on the convective boiling and condensation kinetics of zeotropic mixtures is available in literature. This paper presents a micro-structured heat exchanger designed with a newly developed numerical model, followed by experimental results on the single-phase pressure drop and their implications on the hydraulic diameter.