SIMULATION OF A PARABOLIC TROUGH SOLAR COLLECTOR DEVELOPED IN ENGINEERING EQUATION SOLVER

Resumen

The present study tries to determine the thermal efficiency of a solar parabolic trough collector under non ideal conditions (conditions not too close to the state-of-the-art). Namely, it will be considered some conditions like high wind velocity, low or no vacuum in the HCE annular space (atmospheric pressure or partial vacuum, 10 kPa), materials’ radiative properties lower than the current highest, among others that will be specified. However, the collector’s dimensions, specially from the HCE, are based on the standard measurements of the parabolic trough collector LUZ LS-3 type. Moreover, unlike other studies, it doesn’t consider heat fluxes per length unit, it rather considers heat fluxes for a determined HCE length (4 meters). The simulation was performed on the EES (Engineering Equation Solver) program, considering that EES has a large database of thermal and physical properties of many fluids. EES can incorporate Lookup tables to interpolate and recall properties for fluids not included on the databases (in this case for the analyzed HTFs: Therminol VP-1 and Syltherm 800). The mathematical model was written on EES, and a Diagram Window was created to enter the input values and show the output answers. The equations are based on typical heat transfer models [Forristal, 2003, Incropera, 2006]. It can be stated, as was evidenced, that the efficiency will be reduced as the HTF’s temperature increases because of the thermal losses.