Performance Evaluation of A Jet Impingement Cooling for A Compact Shell and Tube Evaporator


An investigation into flow fields and heat transfer characteristics of a round turbulent jet impinging on a shell and tube evaporator at constant temperatures is numerically conducted in this study. The continuity, momentum, and energy equations are solved using the finite volume method (FVM). Different geometrical parameters are analyzed to determine the optimal design, such as nozzle hydraulic diameter in the range of 1-3 mm, nozzle height from 16 to 32 mm, the number of nozzles from 1 to 3, jet Reynolds number from 3,000 to 25,000, and other independent design variables upon heat transfer, such as tube arrangement and pitch ratio. Results show that the variations of local Nusselt numbers along the pipe surface decreases monotonically from its maximum value at the stagnation point. It is shown that the Nusselt number increases with larger hydraulic diameters, higher nozzle heights, and larger number of nozzles. The optimum tube arrangement that affords the highest heat transfer rate is found in a staggered tube arrangement, with small longitudinal pitches. It is observed that using liquid re-circulator spray nozzles reduces the flow length element of size and shape. Therefore, it is concluded that the impinging jet heat transfer will be augmented using three nozzles to the shell and a tube evaporator.