Investigation of two-phase heat transfer coefficients of cryogenic nitrogen in 160 μm and 65μm microchannels

Published

February 25, 2025

Author(s)

Seungwhan Baek, Ray Radebaugh, Peter Bradley

Abstract

Abstract In this study, two-phase heat transfer characteristics of cryogenic two-phase nitrogen were investigated. This basic information is required for the sequential design of a mixed refrigerant micro-cryocooler. The effective heat exchanger must be designed with a hydraulic diameter (Dh) less than 100 µm. The experimental setup was developed using microchannels with Dh=160 µm and 65 µm. The two-phase heat transfer coefficient was evaluated under different qualities (x), mass fluxes (G=50–150 kg/m2s), and heat fluxes (q''=5–15 kW/m2). The two-phase heat transfer coefficient values ranged between 5000 and 20000 W/m2K. The measured heat transfer coefficient values were compared with the predicted values from existing heat transfer correlations. The correlations derived by Liu and Winterton, were utilized to predict the two-phase heat transfer coefficient for the microchannel in this study. The mean percentage error (MPE) was as low as 25.6%. Moreover, the correlation derived by Karayiannis and Mahmoud, which was derived for the room temperature applications, was found to be suitable for predicting previous cryogenic microchannel literature data (300-10000 µm) .

Citation

Cryogenics

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.cryogenics.2025.104026

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Keywords

heat transfer coefficient, microchannel, two-phase flow, low Reynolds number, cryogenic

Citation

Baek, S. , Radebaugh, R. and Bradley, P. (2025), Investigation of two-phase heat transfer coefficients of cryogenic nitrogen in 160 μm and 65μm microchannels, Cryogenics, [online], https://doi.org/10.1016/j.cryogenics.2025.104026, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957884 (Accessed November 29, 2025)