Empirical Correlation Of Refrigerant R-22 Mass Flow Rate Through Adiabatic Capillary Tube Using Statistical Experimental Design

Abstract

A capillary tube is an expansion and metering device used in small vapor compression refrigeration systems such as household refrigerators and freezers. This paper presents a new empirical correlation for predicting refrigerant R-22 mass flow rate through adiabatic capillary tube using central composite design. The correlation is based on the previous researches that say the mass flow rate depends on four major parameters, namely the length of capillary tube, inner diameter of capillary tube, condenser temperature and degree of sub cooling. In the present study, the experimental data of the capillary tube covers capillary tube length ranging from 0.75 to 1.75 m, inner diameter from 1.11 to 1.40 mm, condensing temperature from 37 to 52^oC and degree of sub cooling from 2 to 14^oC.The correlation was tested with analysis of variance of 5% level of significance and the result showed that the equation model fitted well with the experimental data.