Mathematical Modelling and Experimental Investigation of Collector Efficiency of a Thermosyphonic Solar Water Heating System

The collector efficiency of a thermosyphonic solar water heating system was investigated theoretically and experimentally. Mathematical models were developed and used to predict the system performance. The solar collector with water pipes spreading across its width was also developed, tested and the theoretical results obtained agreed well with the experimental results. The collector efficiency is high especially around mid-day when the solar collector receives the highest energy. The results also reveal the dependency of the system performance on intensity of solar radiation and mass flow rate. Increase in both solar radiation and mass flow rate increases the collector efficiency. Maximum efficiencies of 72.8 and 70.4% were obtained from theoretical and experimental analyses, respectively, at optimum mass flow rate of 0.098 kg/s