Innovative mini-channel design for a compound parabolic solar thermal collector for intermediate temperature applications

The heat flux in the focal region of a compound parabolic collector (CPC) and the receiver's surface is varying and ununiform, and its effective absorption is one of the challenging tasks. It opens new opportunities for suitable and appropriate designs for the receiver. Thus, a new design of the mini-channel receiver is proposed based on fluid flow optimization to address the issue. The pressure drop analysis enables the decision of the dimensions of the proposed mini-channel receiver. MATLAB programming enables flow optimization through a mini-channel receiver under variable solar flux falling its surface to attain the highest possible temperature. The performances of the optimized and parallel fluid flow mini-channel receivers are compared by integrating them with CPC. The results revealed that the thermal gain of CPC-optimized fluid flow mini-channel increases by 23% with minimum pressure drop and shows the variation in the outlet fluid temperature from 82 to 155 °C under the fluid flow rates 1.5–4 l/h. The results show a reduction in the heat loss factor, which ultimately contributed to increasing CPC's efficiency. Thus, the proposed new design of an optimized fluid flow mini-channel receiver will help researchers design and develop efficient solar thermal systems.