Thermal performance of solar air heaters: Mathematical model and solution procedure

摘要: Abstract A mathematical model and solution procedure for predicting the thermal performance of single-pass solar air collectors is presented. By omitting or providing a top glass cover over plane absorber plate, by bottom plate under circulating one both channels so formed, four common types flat-plate collector designs were considered. The surface temperatures walls surrounding streams assumed uniform whereas to vary linearly along collector. In model, was sufficiently short which assumptions valid. considering steady state heat transfer using network analysis procedure, set simultaneous equations mean temperature obtained. Instead solving explicitly, matrix inversion method employed standard sub-routine programme. Because coefficients dependent, approximated allowed be evaluated as first guess. An iterative process then created that enabled calculated. newly-calculated compared with initially-guessed temperatures. repeated until consecutive values differed less than 0.01°C. After this, another section length equal previous added end conditions at inlet second outlet section. determine next Additional sections required overall this predictions wall any could Although only four, are considered here, extended encompass most other designs.