The Effects of Unbalanced Flow on the Thermal Performance of Collector Arrays

Abstract

This paper details a mathematical model and a computer program that were developed to examine the effects of a flow imbalance on the total solar energy gain of a collector array. The model allows for variation in collector geometry, array geometry, collector flow rate, and collector inlet temperature, as well as fluctuations in ambient temperature and incident solar radiation. The program calculates the collector plate temperature, the heat removal factor, the collector heat loss coefficient, and the solar energy collected. The program is written in the BASIC language. It is iterative and uses the collector plate temperature as its test for convergence. The significance of a flow imbalance is explored by a systematic variation of the above parameters. Results indicate a relatively minor penalty for an unbalanced system, provided none of the rows in the array stagnate.