Single phase modeling of linear FRESNEL collectors for direct steam generation process

Direct steam generation (DSG) process using linear FRESNEL collectors has been developed widely in recent years and is one of the most promising solar technologies for thermal power generation, Industrial processes and domestic usage. In this process water as heat transfer fluid (HTF) is heated through a solar field. Continuous breakthroughs are being achieved on improvement of these collectors. A single phase CFD model is developed to calculate the wall temperature of linear Fresnel absorber tubes and fluid properties including temperature, velocity, and pressure. In order to design the collector field and identify the critical condition such as overheating of the absorber tubes, modeling of linear Fresnel collectors is necessary. This study describes the models used for estimation of input solar heat flux on the wall of a single absorber tube. Then the radiating heat flux on the wall of a single tube is calculated based on conditions of solar energy in Iran. The heat flux is then used for numerical finite volume modeling of water heating in the tube. Finally the effect of tube diameter and configurations with more than one tube is investigated.