- Author
-
Choi, J. Y.
|
Kedzierski, M. A.
|
Domanski, P. A.
- Title
- Generalized Pressure Drop Correlation for Evaporation and Condensation in Smooth and Micro-Fin Tubes.
- Coporate
- Korea Testing Laboratory for Industrial Technology, Seoul
National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Thermophysical Properties and Transfer Processes of New Refrigerants. IIR (International Institute of Refrigeration) Commission B1 Conference. Proceedings. October 2-5, 2001,
Paderborn, Germany,
B/4.9-B/4.16 p.,
2001
- Keywords
-
micro-fin tubes
|
pressure drop
|
evaporation
|
condensation
|
alternative refrigerants
|
refrigerants
|
correlation
|
friction factor
|
hydraulic diameter
|
smooth tube
- Abstract
- This paper presents a pressure drop correlation for evaporation and condensation in smooth and micro-fin tubes for lubricant-free refrigerants and refrigerant/lubricant mixtures. The form of the generalized correlation was taken from the Pierre pressure drop model. NIST micro-fin tube pressure drop data for R134a, R22, R125, R32, R407C, R410A, and R32/R134a (25/75% mass) were regressed to a modified Pierre correlation. The NIST database was post-predicted with an average absolute residual of 10.8%. Further validations performed with extensive data from the literature for lubricant-free refirgerants in smooth and micro-fin tubes showed an average absolute residual between measurements and predictions not to exceed 17.6% for the various data sets. The condensation and evaporation pressure drops for different refrigerant/lubricant mixtures werepredicted with average absolute residuals not exceeding 19.6% and 28.0%, respectively.