Effect of Pressure Drop and Air Mass Flow Rate on the Performance of Concentric Coaxial Glass Tube Solar Air Collector: A Theoretical Approach

Abstract

The aim of this research work is to study the combined effects of constant pressure drop and air mass flow rate on concentric coaxial glass tube (CCGT) dimensions of concentric coaxial glass tube solar air collector. A mathematical model is developed in JAVA simulation program to optimize the length and diameter of CCGT by keeping the pressure drop constant for different air mass flow rates. The results show that absorber tube diameter of 0.028, 0.030 and 0.032 m has less dependency on the CCGT length instead of diameter range from 0.034 to 0.048 m for an air mass flow rate of 0.0053 kg/s as compared to 0.0074, 0.0095 and 0.0118 kg/s at a constant pressure drop. The air mass flow rate increases from 0.0053 to 0.0118 kg/s which leads to decrease in forced heat transfer coefficient and exit air temperature. More pumping power is required at high pressure drop with air mass flow rates of 0.0053, 0.0074, 0.0095 and 0.0118 kg/s.