Condensation heat transfer for zeotropic mixtures of propane and n-butane on single tubes and in tube bundles

Kühl J, Zhang Z, Piszko M, Jander JH, Dietl J, El-Hajal J, Gotterbarm A, Rausch MH, Klein T, Fröba AP (2025)

Publication Type: Journal article

Publication year: 2025

Journal

International Journal of Heat and Mass Transfer Elsevier

Book Volume: 248

Article Number: 127176

DOI: 10.1016/j.ijheatmasstransfer.2025.127176

Abstract

This work presents experimental condensation heat transfer coefficients αcond for different binary zeotropic mixtures consisting of propane and n-butane on horizontal single tubes and in tube bundles measured with a setup specifically modified for this purpose. To study the influence of the condensation tube characteristics on αcond, smooth, finned, and high-performance condensation tubes were investigated. The finned tubes include a systematic variation in the fin density and fin height. Besides pure copper, also a copper-nickel alloy was studied as tube material. During the condensation experiments, the vapor composition was measured continuously with the help of Raman spectroscopy, whose application for mixture condensation in a heat exchanger is presented in this work for the first time. The results show that αcond for zeotropic mixtures is significantly smaller than that for the pure substances because of the formation of a so-called diffusion film caused by the preferential condensation of the high-boiling mixture component. In tube bundle experiments, on the other hand, the impinging condensate from upper tube rows obviously break this diffusion film up, resulting in a significant increase of up to 670 % in αcond with increasing irrigation mass flow rate.

Authors with CRIS profile

Julius Kühl Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Zhongwen Zhang Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Maximilian Piszko Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Julius Jander Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Michael Rausch Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Tobias Klein Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP) Andreas Paul Fröba Institute of Advanced Optical Technologies - Thermophysical Properties (AOT-TP)

Involved external institutions

Wieland-Werke AG DE Germany (DE)

How to cite

APA:

Kühl, J., Zhang, Z., Piszko, M., Jander, J.H., Dietl, J., El-Hajal, J.,... Fröba, A.P. (2025). Condensation heat transfer for zeotropic mixtures of propane and n-butane on single tubes and in tube bundles. International Journal of Heat and Mass Transfer, 248. https://doi.org/10.1016/j.ijheatmasstransfer.2025.127176

MLA:

Kühl, Julius, et al. "Condensation heat transfer for zeotropic mixtures of propane and n-butane on single tubes and in tube bundles." International Journal of Heat and Mass Transfer 248 (2025).

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