Geometry Of Solar Tower With Elliptical Torus Mirror

Abstract

An intense increase of research in “green” technologies brings a variety of science fields in common goal to contribute sustainable development. Such an example is concentrated solar power (CSP) which combines knowledge of astronomy, thermodynamics, mechatronics and geometry in one final product. The solar power tower is a system that uses an array of flat, movable mirrors called heliostats to focus Sun’s rays into one focal point which is usually a boiler located on top of central collector tower. This paper will present one possible design of solar power tower by using geometry to relocate its focal point. Most common solutions for solar power tower are shown and they are based on concept where boiler is in plain sight. Idea behind this relocation of focal point in novel construction is that boiler will be isolated from environment conditions and by doing so it can preserve more thermal energy during night. This can be achieved by installing additional mirror on solar power tower which has a shape as revolved partial ellipse. Here will be explained how this additional mirror can be used as economiser for fluid that is being heated in solar power. Paper also explains use of “fat point” at focal point and thus compensate errors that can occur if rays from heliostat are inaccurate.