Theoretical and experimental investigation of heat pipe solar collector

Heat pipe solar collector was designed and constructed at IROST and its performance was measured on an outdoor test facility. The thermal behavior of a gravity assisted heat pipe solar collector was investigated theoretically and experimentally. A theoretical model based on effectiveness-NTU method was developed for evaluating the thermal efficiency of the collector, the inlet, outlet water temperatures and heat pipe temperature. Optimum value of evaporator length to condenser length ratio is also determined. The modelling predictions were validated using experimental data and it shows that there is a good concurrence between measured and predicted results.