A new high-performance flat plate solar collector. Numerical modelling and experimental validation
J. Zheng, Rafel Febrer, Jesús Castro González, Deniz Kizildag, Joaquim Rigola
Abstract
A new concept of flat plate solar collector (FPC) has been numerically studied for optimization purposes from an energetic and exergetic points of view. The highly efficient results have been achieved by adding transparent insulation materials (TIM) made of plastic and aerogel-silica in the cover. The optimum solution has been prototyped and successfully tested. The numerical simulation and the corresponding analysis are performed with a previously developed numerical simulation tool based on an in-house software platform (NEST). An optimization design has been done using this numerical simulation tool objected to higher performance at the (Tin−Tamb)/Ġ>0.074 range, and a new prototype is fabricated with low-cost materials found in the workshop. The final results are compared with previous prototypes that could collect between 2.5 and 1.4 times higher than standard collectors in summer and autumn, respectively. The new prototype has higher performance at (Tin−Tamb)/Ġ>0.074, which makes it competitive in a high-temperature range. Moreover, with the new layer of aerogel-silica, additional protection against overheating is achieved, as the temperatures of the plastic TIM are limited. The new prototype has higher energetic and exergetic efficiency at high-temperature areas, and the inlet temperature at optimized working conditions is higher than the previous prototype. Finally, the energy efficiency at (Tin−Tamb)/Ġ=0.08 could reach 55% and exergetic efficiency 8%. The manufacturing cost of the FPC prototype with TIM and aerogel-silica is about 160 euros per m2.