Manual making of a parabolic solar collector（手工制作的抛物面太阳能收集器）.pdf

Manual making of a parabolic solar collector Gang Xiao Laboratoire J.A. Dieudonné Université de Nice Nice France This article offers an illustrated description of a method to produce a closed parabolic trough solar energy collector box based on the elasticity of the material. What is described here is basically a manual method to make high efficiency solar collectors against very low cost which is particularly suited for teaching research or demonstration purposes. But it is hard for a manually made collector to match the efficiency lifetime and water tightness standard of an industrial product using the same method. It will also cost more than the industrial collector. The method for industrial production of elastic closed parabolic trough boxes will be described in another article later. A parabolic trough solar collector uses a mirror in the shape of a parabolic cylinder to reflect and concentrate sun radiations towards a receiver tube located at the focus line of the parabolic cylinder. The receiver absorbs the incoming radiations and transforms them into thermal energy the latter being transported and collected by a fluid medium circulating within the receiver tube. This method of concentrated solar collection has the advantage of high efficiency and low cost and can be used either for thermal energy collection for generating electricity or for both therefore it is an important way to exploit solar energy directly. Known methods to form the parabolic cylinder reflective surface consist either of forming a curved plate material under high temperature or of adding pre-formed ribs at the back of a flat reflective plate then force the plate to follow the curve of the ribs. Both