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Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube

Abstract

In recent small and medium capacity refrigeration systems, the condenser tubes are provided with micro-fins from inside. The vapour refrigerant at the compressor outlet and the condenser inlet is in superheat state. As it advances in the condenser it is in two phases and at the outlet it is in sub cooled liquid. The heat transfer coefficient (HTC) during condensation of HFC-134a and R-404A in a smooth (8.56 mm ID) and micro-fin tubes (8.96 mm ID) are experimentally investigated. Different from previous studies, the present experiments are performed for various condensing temperatures, with superheating and sub cooling and using hermetically sealed compressor. The test runs are done at average saturated condensing temperatures ranging from 35 C to 60 C. The mass fluxes are between 90 and 800 kg m{sup -2} s{sup -1}. The experimental results indicate that the average HTC increases with mass flux but decreases with increasing condensing temperature for both smooth and micro-fin tubes. The average condensation HTCs of HFC-134a and R-404A for the micro-fin tubes were 1.5-2.5 and 1.3-2 times larger than that in smooth tube respectively. The HTCs for R-404A are less than that of HFC-134a. New correlations based on the data gathered during the experimentation  More>>
Authors:
Sapali, S N; [1]  Patil, Pradeep A [2] 
  1. Govt. College of Engineering, Department of Mechanical Engineering, Shivaji Nagar, Pune, Maharashtra 411 005 (India)
  2. AISSMS College of Engineering, Pune University, Mechanical Engineering Department, Kennedy Road, Near R.T.O., Pune, Maharashtra 411 001 (India)
Publication Date:
Nov 15, 2010
Product Type:
Journal Article
Resource Relation:
Journal Name: Experimental Thermal and Fluid Science; Journal Volume: 34; Journal Issue: 8; Other Information: Elsevier Ltd. All rights reserved
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 42 ENGINEERING; HEAT TRANSFER; VAPORS; TUBES; REFRIGERATION; SUBCOOLING; REFRIGERANTS; COMPRESSORS; MASS; SUPERHEATING; AUGMENTATION; CORRELATIONS; FINS; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE DEPENDENCE; In-tube condensation; Microfin tubes
OSTI ID:
21350383
Country of Origin:
United States
Language:
English
Other Identifying Numbers:
Journal ID: ISSN 0894-1777; ETFSEO; TRN: US10V0540
Availability:
Available from: http://dx.doi.org/10.1016/j.expthermflusci.2010.03.013
Submitting Site:
OSTI
Size:
page(s) 1133-1141
Announcement Date:
Nov 17, 2010

Citation Formats

Sapali, S N, and Patil, Pradeep A. Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube. United States: N. p., 2010. Web. doi:10.1016/J.EXPTHERMFLUSCI.2010.03.013.
Sapali, S N, & Patil, Pradeep A. Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube. United States. doi:10.1016/J.EXPTHERMFLUSCI.2010.03.013.
Sapali, S N, and Patil, Pradeep A. 2010. "Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube." United States. doi:10.1016/J.EXPTHERMFLUSCI.2010.03.013. https://www.osti.gov/servlets/purl/10.1016/J.EXPTHERMFLUSCI.2010.03.013.
@misc{etde_21350383,
title = {Heat transfer during condensation of HFC-134a and R-404A inside of a horizontal smooth and micro-fin tube}
author = {Sapali, S N, and Patil, Pradeep A}
abstractNote = {In recent small and medium capacity refrigeration systems, the condenser tubes are provided with micro-fins from inside. The vapour refrigerant at the compressor outlet and the condenser inlet is in superheat state. As it advances in the condenser it is in two phases and at the outlet it is in sub cooled liquid. The heat transfer coefficient (HTC) during condensation of HFC-134a and R-404A in a smooth (8.56 mm ID) and micro-fin tubes (8.96 mm ID) are experimentally investigated. Different from previous studies, the present experiments are performed for various condensing temperatures, with superheating and sub cooling and using hermetically sealed compressor. The test runs are done at average saturated condensing temperatures ranging from 35 C to 60 C. The mass fluxes are between 90 and 800 kg m{sup -2} s{sup -1}. The experimental results indicate that the average HTC increases with mass flux but decreases with increasing condensing temperature for both smooth and micro-fin tubes. The average condensation HTCs of HFC-134a and R-404A for the micro-fin tubes were 1.5-2.5 and 1.3-2 times larger than that in smooth tube respectively. The HTCs for R-404A are less than that of HFC-134a. New correlations based on the data gathered during the experimentation for predicting condensation HTCs are proposed for wide range of operating conditions. (author)}
doi = {10.1016/J.EXPTHERMFLUSCI.2010.03.013}
journal = {Experimental Thermal and Fluid Science}
issue = {8}
volume = {34}
place = {United States}
year = {2010}
month = {Nov}
}