Numerical investigation of the effects of environmental parameters and geometry on energy absorption for an open-type water-cooled flat-plate solar collector

A two-dimensional mathematical model was developed for predicting the perfo rmance of an open-type water-cooled fiat-plate solar collector, and solved numerically through an that there is an optimum length and tilt angle for t he absorbing plate for which the implicit finite difference method. The eff ects of various environmental and geometric conditions on energy absorption for the collector were investigated. The results predict collector could o btain the highest solar energy absorptance. The latent heat pur of water ev aporation can be 3 to 15 times larger than the sensible heat flux under nor mal operating conditions. The wind speed and the inlet water temperature ha ve a large influence on the energy absorption of the collector The effects of the solar incident flux, the atmospheric humidity and temperature, the a bsorbing plate tilt angle and length, and the water film thickness on the t emperature rise of the water film and/or the absorptance of the collector a re clarified. The open-type flat-plate collector is suitable to operate at lower inlet water temperatures and in regions where the local latitude is i n the range of 20 degreesN-40 degreesN, and the weather is humid and hot wi th low winds. [S0199-6231(00)00202-1].