Effect of geometrical parameters on the performance of plate heat exchanger using milk- water as medium fluids in the channels

Abstract

The present study deals with the selection of optimal geometrical parameters of the plate heat exchangers (PHEs) based on the results obtained by 3-D numerical simulation of flow and heat transfer between milk and water. The investigations are carried out for chevron angle, β = 30°, 45° & 60°, pitch to depth ratio of corrugation, p/d = 2, 2.25, 2.587 & 3.333, enlargement factor, φ = 1.07, 1.197, 1.504, 1.643, 1.789 & 2.094, hydraulic diameter, Dh = 3.99, 4.26, 4.47, 4.77, 5.01 & 5.48, Reynolds number, Re = 60 to 1850, and Prandtl number, Pr = 3.69 to 17.7 using water-milk as well as water-water combinations in the exchanger. For enriching the computational work, the simulated results are validated with present experimental results as well as with previously reported experimental work. Based on the experimental validation, laminar and turbulent models are suggested for various ranges of Reynolds number of water and milk as working fluids. The thermo-hydraulic performance of PHE is evaluated using the JF factor, showing that the chevron angles, β = 30° and β = 60°, perform better respectively in laminar and turbulent regions for both milk and water as cooling fluids. In addition to that, the pitch-to-depth ratio, p/d = 2.25, gives optimum performance for chevron angle, β = 60° plates PHE. Based on the numerically simulated results, the correlations of Colburn and friction factors are proposed in terms of chevron angle, enlargement factor, p/d ratio, and Re for evaluating the thermo-hydraulic performance of the PHEs.