THERMAL SCIENCE

International Scientific Journal

Qin Wang

,

Qinglu Song

,

Chuantong Zhang

,

Bin Sun

,

Sai Zhou

,

Dechang Wang

THEORETICAL ANALYSIS FOR FLOW CONDENSATION HEAT AND MASS TRANSFER OF ZEOTROPIC MIXTURES IN A HORIZONTAL SMOOTH TUBE

ABSTRACT
As the increasingly serious impact of CFC and HFC on the environment, research on zeotropic mixtures plays an indispensable role in many industries. Especially, the study of zeotropic mixtures is essential for optimizing liquefied natural gas system design. As primary constituents of natural gas, methane (R50), and ethane (R170) are equally vital in mixed-refrigerant Joule-Thomson cycles. This work experimentally examines flow condensation heat transfer for R50/R170 blends in horizontal smooth tubes across wide-ranging conditions. A non-equilibrium film theory-based analytical model was proposed to examine heat and mass transfer during binary zeotropic mixture condensation, incorporating vapor-liquid interfacial mass transfer resistances. Rigorous examination quantified impacts of mass flux, saturation pressure, heat flux, and vapor quality on temperature and concentration gradients. The results revealed substantial heat transfer degradation from temperature/mass fraction gradients, exhibiting strong dependency on volatile component concentration and mixture vapor quality. Model predictions demonstrated good agreement with measured condensation heat transfer coefficients for binary refrigerants.
KEYWORDS
zeotropic mixture, Methane and ethane, heat and mass transfer, Nonequilibrium film theory
PAPER SUBMITTED: 2025-06-24
PAPER REVISED: 2025-09-21
PAPER ACCEPTED: 2025-09-26
PUBLISHED ONLINE: 2025-11-08
DOI REFERENCE: https://doi.org/10.2298/TSCI250624189W
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2026, VOLUME 30, ISSUE No. 3, PAGES [1715 - 1726]
REFERENCES
[1] Marak, K. A., Condensation Heat Transfer and Pressure Drop for Methane and Binary Methane Fluids in Small Channels, Ph. D. thesis, Norwegian University of Science and Technology, Trondheim, Norvay, 2009
[2] Zhuang, X. R., et al., Experimental Investigation on Flow Condensation of Methane in a Horizontal Smooth Tube, International Journal of Refrigeration, 78 (2017), June, pp. 193-214
[3] Zhuang, X. R., et al., Experimental Investigation on Flow Condensation of Zeotropic Mixtures of Methane/Ethane in a Horizontal Smooth Tube, International Journal of Refrigeration, 85 (2018), Jan., pp. 120-134
[4] Gong, M. Q., et al., Study of the Single-Stage Mixed-Gases Refrigeration Cycle for Cooling Temperature-Distributed Heat Loads, International Journal of Thermal Sciences, 43 (2004), 1, pp. 31-41
[5] Song, Q., et al., Experimental and Analytical Investigation on Flow Condensation Heat Transfer of Zeotropic Mixtures Of Tetrafluoromethane/Ethane, Applied Thermal Engineering, 197 (2021), 117382
[6] Song, Q., et al., Flow Condensation Pressure Drop Characteristics of Zeotropic Mixtures of Tetrafluoromethane/Ethane: Experimental and Analytical Investigation, International Journal of Heat and Mass Transfer, 182 (2022), 122045
[7] Lim, W., et al., Current Status and Perspectives of Liquefied Natural Gas (LNG) Plant Design, Industrial & Engineering Chemistry Research, 52 (2013), 9, pp. 3065-3088
[8] Tzabar, N., Binary Mixed-Refrigerants for Steady Cooling Temperatures between 80 K and 150 K with Joule-Thomson Cryocoolers, Cryogenics, 64 (2014), Nov.-Dec., pp. 70-76
[9] Wang, Y., et al., The Effective Refrigeration Temperature Zone Expressed by Partial Molar Enthalpy Difference of Each Component in Mixed-Refrigerant Joule-Thomson Refrigerators, Cryogenics, 128 (2022), 103590
[10] Wang, Y., et al., Evaluation and Analysis from Pressure and Component in the Single-Stage Mixed-Refrigerant Joule-Thomson Cooler from 100 K to 200 K, Energy, 319 (2025), 135018
[11] Zou, L., et al., Experimental Study on the Characteristics of R1150/R600 Mixed Refrigerant Joule-Thomson Low-Temperature Freezer, Applied Thermal Engineering, 249 (2024), 123349
[12] Colburn, A. P., Drew, T. B., The Condensation of Mixed Vapors, Trans AIChE, 33 (1937), pp. 197-215
[13] Price, B. C., Bell, K. J., Design of Binary Vapor Condensers Using the Colburn-Drew Equations, Proceedings, AIChE Symp. Ser., 1974, No. 70, pp. 163-171
[14] Jin, D. X., et al., Prediction of in-Tube Condensation Heat Transfer Characteristics of Binary Refrigerant Mixtures, International Journal of Refrigeration, 26 (2003), 5, pp. 593-600
[15] Wang, L., et al., Condensation Heat and Mass Transfer Characteristics of Low GWP Zeotropic Refrigerant Mixture R1234yf/R32 Inside A Horizontal Smooth Tube: An Experimental Study and Non-Equilibrium Film Model Development, International Journal of Thermal Sciences, 170 (2021), 107090
[16] Wang, L., Dang, C., et al. Experimental and Theoretical Study on Condensation Heat Transfer of Non-Azeotropic Refrigerant Mixtures R1234yf_R32 Inside a Horizontal Smooth Tube, Proceedings, International Refigeration and Air Conditioning Conference, West Lafayette, Ind., USA, 2012
[17] Wang, L., et al., Study on Condensation Heat Transfer Characteristics of Non-Azeotropic Binary Refrigerant Mixture R1234yfR32 Inside Small-Scale Horizontal Smooth Tubes, Proceedings, Heat Transfer Summer Conference, ASME, Minneapolis, Minn., USA, 2013, pp. 1-7
[18] Deng, H., et al., Numerical Study of Heat and Mass Transfer of Binary Mixtures Condensation Mini-Channels, International Communications in Heat and Mass Transfer, 58 (2014), Nov., pp. 45-53
[19] Zhang, Y., et al., Analytical Model for the Condensation Heat and Mass Transfer Characteristics of Binary Zeotropic Mixtures, International Journal of Heat and Mass Transfer, 142 (2019), 118487
[20] Wu, Z., et al., A Novel Condensation Heat Transfer Correction Based on Non-Equilibrium Film Theory and Degradation Mechanism for Zeotropic Mixture, International Communications in Heat and Mass Transfer, 160 (2025), 108342
[21] Yan, S., et al., A New Heat Transfer Model Based on Non-Equilibrium Film Theory for Annular Flow Condensation of Binary Zeotropic Mixtures. International Journal of Heat and Mass Transfer, 205 (2023), 123899
[22] Yan, S., et al., A New Heat Transfer Model Based on Non-Equilibrium Theory for Annular Flow Condensation - Part Ⅱ: Ternary Zeotropic Mixtures, International Journal of Heat and Mass Transfer, 221 (2024), 125026
[23] Zhuang, X., et al., Experimental Investigation on Flow Condensation of Zeotropic Mixtures of Methane/Ethane in a Horizontal Smooth Tube, International Journal of Refrigeration, 85 (2018), Jan., pp. 120-134
[24] Lemmon, E. W., et al., The NIST Standard Database 23, Version 9.1, Applied Chemicals and Materials Division, Nat. Inst. of Stand. and Tech., Boulder, Cal., USA, 2013
[25] Koyama, S., et al., Condensation of Binary Refrigerant Mixtures in a Horizontal Smooth Tube, Thermal Science and Engineering Progress, 6 (1998), 4, pp. 123-129
[26] Lamourelle, A. P., Sandall, O. C., Gas Absorption into a Turbulent Liquid, Chemical Engineering Science, 27 (1972), 5, pp. 35-43
[27] Poling, B. E., et al., The Properties of Gases and Liquids, 5th ed., McGraw-Hill (Chapter 11), New York, USA, 2000
[28] Kim, C.-H., Kim, N.-H. Condensation Heat Transfer and Pressure Drop Characteristics of Low GWP R-404A Alternative Refrigerants in a Multiport Tube Having Axial Microfins, International Journal of Heat and Mass Transfer, 188 (2022), 122624
[29] Garimella, S., et al., Condensation of Zeotropic Mixtures of Low-Pressure Hydrocarbons and Synthetic Refrigerants, International Journal of Heat and Mass Transfer, 162 (2020), 120301
[30] Mazumder, S., et al., Study of in-Tube Condensation Heat Transfer of Zeotropic R32/R1234ze(E) Mixture Refrigerants, International Journal of Heat and Mass Transfer, 169 (2021), 120859
[31] Wang, L., et al., Condensation Heat and Mass Transfer Characteristics of Zeotropic Refrigerant Mixture R1234yf/R32 Inside Small-Scale Tube: Flow Patterns Observation and Non-Equilibrium Film Model Calculation, International Journal of Thermal Sciences, 191 (2023), 108347
PDF VERSION [DOWNLOAD]
Theoretical analysis for flow condensation heat and mass transfer of zeotropic mixtures in a horizontal smooth tube

© 2026 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence