Investigation of Heat Transfer Enhancement in a Parabolic Trough Collector with a Modified Absorber

Abstract

Parabolic trough collectors are widely used as a solar energy recovery device, with the reflected concentrated solar energy focused mostly to a single cylindrical tube. Experiments are conducted on a single tube absorber and a newly designed modified absorber with an absorber plate and a linear array of water tubes to utilize the most of the irradiated heat. Three dimensional, conjugate computational fluid dynamic analyses was carried out using a commercial software Ansys Fluent to analyse both single tube and modified absorber designs. The results from the present computations show good agreement with that of the present experiments. The solar energy recovery efficiency of the modified absorber was found to be higher than the single tube, in the form of increased water temperature. The proposed modified absorber can be an effective alternate for the parabolic trough collector systems. The day average efficiency of the proposed modified absorber system was found to be 42.1% which is higher than the conventional single tube absorber systems presently in use.