Effect of chevron angle on the thermofluids performance of shell-and-plate heat exchangers - A numerical approach

This study conducts a detailed numerical study upon the effect of chevron angle on the thermofluids characteristics of shell-and-plate heat exchangers. The plate diameter is 215 mm and the chevron angles (beta) are 30 degrees, 45 degrees, 60 degrees, and 75 degrees. Simulations are performed with Reynolds number ranging from 200 to 1000. The heat transfer and frictional performance are termed as Nusselt number (Nu) and friction factor (f), and results for both shell and plate side are reported. The Nusselt number and friction factor in the shell side are increased with the rise of chevron angle. For the same inlet flowrate, the pressure profile in the shell side changes significantly with the chevron angle, from uniform (beta = 30 degrees) to concave (beta = 45 degrees similar to 60 degrees) and finally to slightly convex (beta = 75 degrees) while the pressure profile in the plate side is always convex. In the plate side, the Nusselt number increases with the rise of chevron angle. But the lowest friction factor occurs when beta = 45 degrees due to a better flow distribution. The heat transfer performance in the shell side is superior to the plate side due to the presence of the inlet/outlet manifold in association with the chevron angles. Based on the performance evaluation criteria, it is found that the best overall performance occurs at a chevron angle of 45 degrees. This angle is applicable in both shell side and plate side. For the shell side, the index is about 25 %, 60 %, and 340 % higher than those of beta = 75 degrees, 60 degrees, and 30 degrees, respectively at a Reynolds number of 300 at the shell side. For the plate side, the index amid beta = 75 degrees, 60 degrees, and 45 degrees is roughly the same when the Reynolds number is lower than 500, and the index is about 220 % for beta = 45 degrees when compared to beta = 30 degrees at a Reynolds number of 300.