Parabolic Troughs without Solar Tracking System
Third International Conference on Applied Energy, Perugia, Italy (2011)
Wattana Ratismith and Urith Archakositt
Energy Research Institute, Chulalongkorn University, Bangkok 10330 Thailand
In the general operation of a solar collector, the concentrating systems require sun tracking to maintain sunlight focusing at the collector. In addition, the solar collector cannot work effectively in diffused light conditions, therefore output from the system drops drastically in a cloudy condition as the diffused light cannot be concentrated passively. Consequently, it faces a serious problem in utilizing such a solar collector to collect solar energy, especially in the rainy season. The goal of this research is to design a new solar collector, which does not contain a solar tracking system and has an ability to collect the diffused sunlight. Newly developed system consists of three deep parabolic troughs, with low focus points facing the sun at different angles and the elongated cross section tubes at the axis of the trough. The salient feature of this design is that the system can collect the sunlight energy at every angle with no moving part, and at the same time can receive the diffused light. This collector yields higher temperatures than flat plate solar collector, the maximum temperature in evacuated tube is 146 degrees Celsius, and is therefore suitable for heating, drying or cooling application.