Optimal arrangement of structural and functional parts in a flat plate integrated collector storage solar water heater (ICSSWH)

Parameters that affect the efficiency of a flat plate integrated collector storage solar water heater (ICSSWH) are examined experimentally and numerically. This specific ICSSWH contains water that is not refreshed. The service water is heated indirectly through an immersed heat exchanger (HE) in contact with the front and back major surfaces. A forced convection mechanism consisting of a pump that brings the storage water into motion by recirculation is used for heat transfer intensification. The two major (front and back) flat plate surfaces need to be well interconnected so that they are not deformed by the weight of the contained water and the exerted high-pressure. Two main factors that influence the performance are optimized: the position and size of the recirculation ports and the arrangement and size of the interconnecting fins. Both factors are explored to maximize the velocity flow field of the recirculated storage water. Consequently, the heat transfer rate between the two water circuits is maintained at high levels. Various 3D computational fluid dynamics (CFD) models are developed using the FLUENT package. An experimental model, made by Plexiglas, is used for the visualization of the flow field. Flow velocities are measured using a laser doppler velocimetry (LDV) system. The optimal arrangement increases the mean storage water velocity by 65% and raises the outlet temperatures up to 8 °C.