Impact of suction line on evaporator effectiveness in refrigeration cycle

Abstract

The effect of suction line on the evaporator performance with the using of R-134a has been investigated experimentally. Three types of suction lines (lateral, concentric, coil) have been used with various refrigerant flow rates and air velocities. The results of the concentric suction line gave the highest values of the coefficient of heat transfer compared to the other types. Moreover, the maximum increase of the internal heat transfer coefficient (hi) and overall heat transfer coefficient (Uo) was achieved for the reference capillary tube as 16% and 50% respectively, when the mass flow rate of refrigerant is 14.87 kg/h and air velocity 3.8 m/s. In addition, the results displayed that the largest values of evaporator effectiveness (ε) have been obtained, when utilized the concentric suction line compared the other types. Thereby, the internal heat transfer coefficient was increased by 9.24% for the concentric suction line with the increasing of air speed from 1.8 m/s to 3.8 m/s at flow rate of the refrigerant is 14.87 kg/h. Finally, the best suction line according to all results such as hi, Uo and ε is the concentric line compared the other types.

Keywords

• Capillary tube
• Suction line
• Evaporator effectiveness
• R134a