Determination of Parabolic Trough Solar Collector Efficiency Using Nanofluid: A Comprehensive Numerical Study

Due to significant reduction in fossil fuel sources, several researches have been conducted recently to explore modern sources of renewable energy. One of the major fields in the category of renewable energy harnessing devices is parabolic trough solar collector (PTC). Several parameters have effect on the overall efficiency of the PTCs. As the effect of these parameters is coupled to each other, a comprehensive investigation is necessary. In the present study, a numerical analysis is performed to examine the efficiency of PTCs via variation of several governing parameters (e.g., wind velocity magnitude, nanoparticles volume fraction, inlet temperature, and reflector's orientation). A detailed set of absorber, reflector, and protection glass in addition to the surrounding environment is modeled to capture sufficiently accurate data. The working fluid is assumed to be nanofluid to inspect the advantage of metallic nanoparticle addition to the base fluid. The Monte Carlo radiation tracing method is utilized to calculate the solar gain on the absorber tube. According to the obtained results, the efficiencies are reduced by 1–3% by rotating the reflector by 30 deg relative to wind direction. Moreover, 14.3% and 12.4% efficiency enhancement is obtained by addition of 5% volume fraction of Al₂O₃ to the base synthetic oil for horizontal and rotated reflectors, respectively.