Edinburgh Napier University

  Stratification inside the water storage tank of a solar heater is a desirable natural phenomenon that improves the collector output. For an ICS storage heater type, where the storage tank is in direct contact with the heating surface (absorber plate), stratification becomes more important as it plays an additional role of defining the heat gain characteristics. In the present research, stratification has been studied for a simple flat plate integrated collector storage (ICS) type heater at various inclinations and applied heat flux values. Experimental results have been compared to CFD results and good agreement is found between the two. The influence of stratification on the heat gain characteristics has also been examined. As the collector can be mounted at different angles to maximize solar gain at different latitudes, the angle of inclination of the solar water heater can vary in range
0°-90°. This variation in angle influences the stratification pattern. The study of stratification is important for determining the weighted average temperature, which is the sole parameter to evaluate the total heat gained by the water inside heater. It was found that stratification changes with the change in the angle, applied heat flux and time. These changes were experimentally recorded and analyzed to evaluate the thermal response of the system to the
stratification. CFD studies were also carried out for deeper insight as the experimental setup did not provide finer details. The results can be used for designing outlets for ICS heaters at various locations.