Study of the Fixed and Concentrated Type Reverse Flat Plate Solar Collector: (2nd Report, Experimental Analysis under the Actual Outdoor Insolation)

A reverse flat plate solar collector is discussed in the present paper. A laboratory scale collector which has a 2.28 m² aperture area and a 1.79 concentration ratio has been designed and constructed, taking into account the optimum design analysis reported in our previous paper. The performance of the collector has been measured under an actual solar insolation at Yokohama, Japan. The experimental results show that the heat loss from the absorber plate is reduced to half of that of the conventional flat plate collector, and the collective efficiency becomes significant even under higher collecting temperatures due to the possible reduction of the natural convection heat losses from the absorber plate.