The effect of vapor flow direction on falling film heat transfer was experimentally investigated by using water. Parallel flow (both water and vapor downwards) showed higher heat exchange performance than counterflow(downward water and upward vapor). ...
The effect of vapor flow direction on falling film heat transfer was experimentally investigated by using water. Parallel flow (both water and vapor downwards) showed higher heat exchange performance than counterflow(downward water and upward vapor). The difference became significant as the vapor flow rate was increased. It is supposed that the uprising vapor disturbs the solution film flow and heat transfer is reduced by uneven distribution or detachment of water film.