Heat transfer correlation for the V-groove solar collector

The performance of solar collectors of conventional design can be base on absorber shape factor by supposing fully developed turbulent flow. A mathematical model has been developed from the energy balance equations of the solar collector system to predict the value of heat transfer coefficient. The Charters correlation has been modified by adding a constant, K. This value is determined by comparing the theoretical efficiency with the efficiency from the experimental data. Since the heat transfer coefficients are temperature dependent, an initial values of the mean temperatures of the glass cover, the plate and the backplate have been approximated which allowed the heat transfer coefficients to be evaluated as a first guess. An iterative procedure have been developed that enabled the absorber's mean temperatures of the collector to be calculated. The newly calculated mean temperatures were then compared with the initially guessed temperatures. The iterative procedure was repeated until consecutive mean temperature values differed by less than 0.01°C. This mathematical model can also be apply to other solar collector with different kind of absorber plate in order to get the value of K.