Abstract:

An experimental study was conducted to demonstrate the effect of the capillary tube length on the refrigeration system performance by adding heat exchanger. The heat exchanger was designed by welding 70cm of the capillary tube with the suction line laterally, which included different lengths of the capillary tubes are 160, 175, 190cm. Besides, the experimental part has been tested at different refrigerant flow rates and air fan velocities of the condenser for each case of the adiabatic and nonadiabatic capillary tube. The experimental results showed an increase in the system performance by 17.96% with a decrease in capillary tube length from 190 to 160 cm for the nonadiabatic capillary tubes at the mass flow rate was 17.3kg/hr and air velocity 3m/s. In addition, the increase in the air-speed of condenser has led to elevate COP by 17.47% at the mass flow rate of 18.9 kg/hr and the capillary tube length of 190 cm. Finally, at the capillary tube length 190cm and refrigerant mass flow rate 2.4g/s is achieved the maximum enhancement of the refrigeration system performance and exergy efficiency by 6.7% and 35% at airspeed 1m/s and 3 m/s respectively compared to the reference one of the adiabatic capillary tubes.

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