Energy Analysis of the Solar Water Heater with Secondary Reflectors

In general, a majorly accepted method of converting solar energy into thermal energy is by using flat plate collectors. The elementary function of these collectors is to heat water at a certain temperature by using solar energy and yield the hot water at a higher temperature can be used for boiling the vegetables by solar cooking, for yielding the saline water from the salty water by using solar desalination and for space heating and cooling by using solar refrigeration and air conditioning processes. In this paper, an attempt has been made to increase the water outlet temperature by adding a plane mirror or reflector along the North–South direction at the same tilting angle of the flat plate collector. Experiments were also conducted with and without reflector on the same collector by varying the mass flow rates, and at different solar insolation. It is noticed that with the added secondary reflector, the solar water heater's overall instantaneous collector efficiency is more than the plain solar flat plate water heater. It is clearly observed that even though the added weight for the collector by the inclusion of the reflective mirrors, but eventually boost the outlet temperature at 5° and 8% of enhancement in conversion efficiency of the collector.