Manufacturing of a parabolic trough concentrating collector test rig and a “LASER-Screen” technique for measuring actual focal length and light interceptance of the collector

摘要

A portable parabolic trough-concentrating solar collector test rig was designed, and fabricated using locally available materials and technique. A trough made of any materials and the energy collection element of any geometry with maximum aperture area of 80×100cm2and 2.5×100cm2respectively can be fitted readily in the support structure of the rig. A two-axis manual tracking system allows the rig to track the sun daily from east to west for every 5° interval, and seasonally from 50°North to 80°South for every 15°. In addition to this, actual focal length and light interceptance were investigated applying customised “LASER-Screen” technique. An average light interceptance of the rig for a 2.5 cm diameter absorber tube was measured to be 85.9%. The focal length of the 100 cm long test rig was found to be 18.167±1.35cm. The test rig will facilitate to investigate the energy potential in Chittagong region of Bangladesh.