EXPERIMENTAL STUDY OF THE EFFECT OF EVAPORATOR TEMPERATURE ON VARIATIONS IN CAPILLARY TUBE LENGTH IN A REFRIGERATOR TEST APPARATUS

Abstract

This study aims to determine the effect of capillary tube length on the temperature and pressure of the evaporator as well as the performance of the refrigeration system using R134a refrigerant. Three variations of capillary tube lengths were used: 900 mm, 1100 mm, and 1300 mm, with a diameter of 0.070 inches. The experimental method was conducted using a refrigeration system and heat pump with measurements of discharge pressure, suction pressure, condenser temperature, evaporator temperature, and compressor current. The results show that the 900 mm capillary tube produces the highest pressure (108 Psi) but the lowest COP (3.32), while the 1100 mm capillary tube produces the highest COP of 3.50. This study contributes to the optimization of small-scale refrigeration system design and provides empirical understanding of the effect of capillary tube geometry on system performance.