AN EMPIRICAL-MODEL FOR SIZING CAPILLARY TUBES

This paper presents an empirical model that has been developed to size adiabatic and non-adiabatic capillary tubes for small vapour compress ion refrigeration systems, in particular, household refrigerators and freezers. The model is based on the assumption that the length of a ca pillary tube is dependent on five primary variables, namely the capill ary tube inner diameter, the mass flow rate of the refrigerant in the capillary tube, the pressure difference between highside and lowside, the refrigerant subcooling at capillary inlet and the relative roughne ss of the capillary tube material. The model is validated with previou s studies over a range of operating conditions and is found to agree r easonably well with the experimental data for HFC134a. Copyright (C) 1 996 Elsevier Science Ltd and IIR