Investigation of the thermal behavior of water flow within parallel tubes in a solar collector

This paper discusses the numerical simulation of the thermal behavior of steady-state water flows within parallel tubes in a plane solar collector. The CFD modeling technique, which is based on the finite volume method, has been implemented with the SIMPLE algorithm. The governing equations of the flow are those of Navier-Stokes, coupled with the energy conservation equation, and solved by using the computer software FLUENT. The profiles of water temperature are analyzed for different mass flow rates. A considerable increase in the heat transfer between the absorber wall and the tubes was observed at the low velocity of water flows. The lower mass flow rate allowed a longer residence time of fluid, and the slower mass flow yielded an increased outlet temperature.