An experimental investigation of performance of a 3-D solar conical collector at different flow rates

The shape of a solar collector is an important factor in solar-to-thermal energy conversion. Conical shape is one of the stationary and symmetric shapes that can be employed as a solar water heater. Flow rate of working fluid on the solar collector has an important effect on the efficiency of the collector. The present study is an experimentally investigated of the performance of the solar conical collector with 1m2 of absorber area at different volumetric flow rates. Water was used as the working fluid with the volumetric flow rate between 0.35-2.8 lit/min and the experiment was held in the ASHRAE standard conditions. The results demonstrated that the efficiency of the conical collector is increased by increasing the flow rate of the working fluid; in addition, the difference between inlet and outlet temperatures is decreased. The maximum recorded outlet-temperature of the collector during the experimental tests was 77.1 0 C and the maximum value of thermal efficiency was about 60%.