Development of a Solar-Flux Tracker for Parabolic-Trough Collectors

摘要

The development of a solar-flux tracker for application to a parabolic-trough solar-thermal collector is described. Tests were conducted at the Collector Module Test Facility and Performance Prototype Trough Test Facility on a resistance wire-type solar-flux sensor. The device consists of two fine wires installed along each side of the absorber tube parallel to the axis. The wires change resistance as a function of the solar flux arriving at the absorber from the reflectors. The resistance of the two wires is compared to produce a null signal when both wires are equally illuminated. The signal from the wires is used in combination with a microprocessor control system to drive the collectors to the optimum tracking angle. Comparisons are made between the performance of the flux tracker, a computer-based tracker, and a shadow-band tracker. (ERA citation 08:012180)