AUGMENTATION OF HEAT TRANSFER RATES IN THE CONDENSERS OF A DOMESTIC REFRIGERATOR RUN ON AN ECOFRIENDLY REFRIGERANT

Abstract

This work presents an experimental study on the augmentation of heat transfer rate from the condenser of in a domestic refrigerator using eco-friendly refrigerants. A refrigerator designed to work with R-12 with a gross capacity of 165 liter is used in the experiment. The consumed energy, compressor power and refrigerant temperature and pressure at the inlet and outlet of the compressor are recorded and analyzed as well as the distributions of temperature at various positions in the refrigerator. The experiments are conducted with the refrigerants under the same no load condition at a surrounding temperature of 310 C and by working with R-1 2 and R-1 34a alternatively. In order to carry out the investigation a test condenser tube similar to that used in 165Litre capacity refrigerator was fabricated in the laboratory and tested. The data's were collected for the following range of operating parameters. 1) Refrigerant Used: -R-12, R-134a 2) Test section: Air-cooled Condenser 3) Condenser: Material-Copper Inside Diameter - 4.13mm Outside Diameter- 6.00mm Length of the Test Condenser— 9.3m 3) Surface Area: - Plane Tube- 0.1753m2 Enhanced Tube - 0.2062in2 4) Test Conditions: - Plane Tube Condenser with Refrigerant R-12 Plane Tube Condenser with Refrigerant R-134a Enhanced Tube Condenser With Refrigerant R-12 Enhanced Tube Condenser With Refrigerant R-1 34a iii Heat Transfer Coefficients for on the four test conditions were calculated using the appropriate correlation and were compared. The enhanced tubes were found to perform better than the plane tube in terms of heat transfer coefficient. An increase of around 8.7% to 15.4% in heat transfer coefficient was found for the enhanced tube over the plane tube values. The literature review of natural condensation process inside the tube was conducted in order to gain an insight into the complex mechanism of condensation An addition to it literature on the use of eco-friendly gases in domestic refrigerator was also conducted to see the current trends in the field of domestic refrigerator. iv