Experimental Study the Effect of Absorbing Tube Diameter on the Performance of Compound Parabolic Concentrator Solar Collector

Abstract

A system of test rigs of solar collectors with the compound parabolic concentrator (CPC) have designed to study the performance namely (heat flux and efficiency) for all the solar collectors. The acceptance angle of the CPC taken at 45⁰ for all the solar collectors. The system used to study the effect of absorbing tube diameter on the solar collector performance. A halogen light used as energy source with different absorber tube diameters (0.75, 1, and 1.5) inch used. It has observed that the relationship between the time with the readings of water temperature inside the absorber tube and the performance results show that there are three regions for variation for all collectors. The variation for the water temperature, heat flux and efficiency in the first region varied sharply, in the second region varied gradually and in the third region remained constant. The compering performance results between the different solar collectors with different absorber tube diameters show that the collector with 1.5-inch absorber tube diameter gives the best performance than the others. Where the percentage increase in the temperature for the collector with absorber tube diameter of 1.5 inch compering with the other diameters ( 0.75 , 1 ) inch are (28.3 and 20.7) respectively While in case of heat flux are (69.8 and 53.4) and for the efficiency are (68.8 and 28).