Numerical Simulation of a Parabolic Trough Solar Collector Considering the Concentrated Energy Flux Distribution
Abstract
Concentrated solar power plants are one of the most promising renewable options for electric generation. Nowadays, parabolic trough collectors (PTC) are the most proven, widespread and commercially tested technology available for solar harnessing (Price et al. 2002). Most of the parabolic trough plants deployed operate between 290 and 390oC using oil as heat transfer fluid (HTF). A PTC is constructed as a long parabolic mirror with a dewar tube running its length in the focal line. The HTF runs through the tube and absorbs the concentrated sunlight. The surface of the receiver is covered with a selective coating which has a high absorptance for solar radiation but low emittance for thermal radiation. A glass envelope is used around the receiver tube to reduce the convective heat losses with vacuum or air in the space between the receiver and the cover. The PTC is aligned to the north-south axis and tracks the Sun from east to west as it moves across the sky using a tracking mechanism system.