An optimal design method for an air-heating solar energy collector

Graduation date: 1980Some desirable features of a solar energy collector are listed\ud and a collector design is presented which incorporates their features.\ud As the collector is operated, air flows within the collector enclosure\ud and is heated as it passes through a porous radiant energy receiver\ud mounted in the enclosure. The porous energy receiver consists\ud of sheets of blackened expanded metal.\ud A hardware model of the experimental collector was constructed to\ud allow comparison of this design with a typical flat-plate air-heating\ud collector. Testing demonstrated that the experimental collector was\ud approximately twice as efficient as the standard flat-plate collector.\ud This performance differential was largely due to manipulation of airflow\ud paths within the enclosure of the experimental collector.\ud A mathematical model of the experimental collector was developed\ud and correlated to the hardware model. This hardware-software correlation\ud provided insight into the radiant energy and airflow distributions\ud within the porous receiver and enabled investigation of the sensitivity\ud of collector performance to changes in design parameters such as air\ud flowrate, receiver sheet thermal conductivity, etc.\ud The material cost for the experimental collector is approximately\ud $3-$4 per square foot (1979 prices). Efficiency for the collector\ud is 75%-85%. The collector is readily adaptable to a wide variety of\ud housing designs and architectural styles and is simple to construct