Optimizing design of a Linear Fresnel Reflector for process heat supply

摘要

Lineal Fresnel Reflectors (LFR) is a promising technology in the field of concentrating solar thermal collectorsrnwhich presents several advantages in comparison with the widely used parabolic-trough collectors (PTC). Arnmethodology to properly design a LFR is presented as well as several issues arisen out the study of a particularrncase. As first step, a brief review was performed to select the proper receiver configuration, resulting in arntrapezoidal cavity with multitube absorber receiver. Secondly, several stages of the optimized process werernfollowed using an in-house ray tracer computer code to simulate the optical behavior of the system. Differentrncharacteristics, as width of the mirrors, number of rows, mirror geometry profile, height, length andrnconfiguration of the receiver, were optimized setting the power impinging in the absorber tube surface as thernobjective function. According to the results obtained, the shape of the mirrors was stablished based on thernoptical advantages that parabolic mirrors have over flatted ones. The point strategy was focused on achieving arnhomogeneous flux in the receiver tubes surface. The height of the receiver over the mirrors plane was selectedrnas the one that maximizes the impinging power. A practical analysis related with the facilities characteristicsrnwas carried out to set the number and width of mirrors. In addition, a thermal balance between the impingingrnpower and the thermal energy gained by the heat transfer fluid (HTF) was performed to calculate the length ofrnthe receiver tubes. Finally, the results of the analytical model were cross checked with a ray tracer softwarern(Tonatiuh), with satisfactory results.