Horizontal Convective Condensation of Alternative Refrigerants Within a Micro-Fin Tube

Published

December 1, 1997

Author(s)

Mark A. Kedzierski, J Goncalves

Abstract

This paper presents Local convective condensation Measurements for four refrigerants: R134, R410A (R32/R125, 50/50 % mass), R125, and R32 in a micro-fin tube. Both heat transfer and pressure drop measurements are provided. The heat transfer degradation associated with R410A was shown to be relatively small and believed to be mostly due to nonlinear property effects. The measured convective condensation Nusselt numbers for all of the test refrigerants where correlated to a single expression consisting of a product of dimension less properties. The correlation was shown to predict some existing data from the literature well. The correlation poorly predicted the heat transfer performance of cross-grooved, micro-fin tubes. The pressure drop measurements for the micro-fin tube were satisfactorily predicted by an existing correlation for flow boiling pressure drop in a smooth tube.

Citation

NIST Interagency/Internal Report (NISTIR) - 6095

Report Number

6095

Volume

6

NIST Pub Series

NIST Interagency/Internal Report (NISTIR)

Pub Type

NIST Pubs

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Keywords

building technology, condensation, enhanced heat transfer, fluid heating, micro-fin, pressure drop, refrigerant mixtures

Citation

Kedzierski, M. and Goncalves, J. (1997), Horizontal Convective Condensation of Alternative Refrigerants Within a Micro-Fin Tube, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860754 (Accessed October 20, 2025)