Collector for solar radiation energy - has parabolic reflector and elliptical absorber tube proportioned for maximum collecting efficiency

摘要

Collector has a parabolic reflector (1) facing the incident sunlight. The absorber (2) tube through which liquid to be heated flows has an elliptical cross section. The centre of the ellipse is at the focus of the parabola. The area (f) of the opening of the parabola is at least 1.8 times the surface of the absorber tube. The cross section of the absorber is such that at least 90% of radiation which is within 14 deg. of the axis of the parabola falls on the absorber. The ratio of the major and minor axes (a,b) of the ellipse is between 2 and 2.5.