A new application for solar energy is investigated. It may be applied mainly in industries which use fuel oil as a major source of energy. Because this fuel is highly viscous at ambient temperature, it is usually heated to about 50 degrees C and stored at that temperature. This temperature level is typically achieved in solar applications by the use of flat-plate collectors. A conventional flat-plate collector is filled with fuel oil, and its performance is studied both theoretically and experimentally. The collector is also compared in performance with another identical collector which is filled with water. It was found that, for the same inlet temperature and incident radiation; the exit temperature from the fuel oil collector is higher than that for water. The instantaneous efficiency for the fuel oil collector, however, was found to be less than that for water by about 25%. (C) 1997 Elsevier Science Ltd.
