Edinburgh Napier University

  A simple low cost integrated collector storage solar water heater (ICS-SWH) which has the potential to substantially reduce domestic energy use was proposed for simulation. The
system takes the form of a rectangular-shape incorporating the solar collector and storage tank into a single unit. The incorporation of extended surface fins are a good way of enhancing the construction for an inexpensive SWH and to achieve an increase in efficiency of the system. The thermal performance of the systems is critically dependant on the convective heat transfer coefficient occurring on the waterside of the inclined absorber plate and fins. A Computational Fluid Dynamic (CFD) study was undertaken to model flow and heat transfer in the three-dimensional (3D) SWH geometry. A first analysis was undertaken for a four fins collector designed at Napier University, Scotland, in order to improve its performance. The 3D CFD analysis allowed the optimisation of fin spacing to improve the ICS-SWH performance to create a new ICS-SWH design. Global water temperature in the collector was found to increase without impeding the flow between the fins. A minor decrease in temperature gradient was observed but stratification remained.