A coupled modeling framework for investigating flow maldistribution in cross-flow-corrugated plate heat exchangers

Abstract

Accurate prediction of the impact of flow maldistribution on the thermo-hydraulic behavior of plate heat exchangers is important for thermal design and optimization in a number of practical applications. In this paper, a coupled modeling framework, consisting of a heat transfer model and a hydraulic model, is proposed for quantitatively evaluating the impact of maldistribution on the thermo-hydraulic performance of a cross-flow-corrugated plate heat exchanger. The numerical results of the proposed approach are validated by comparison with experimental data. Using the coupled model, the flow distribution nonuniformity, heat exchanger effectiveness deteriorations, and pressure drop deviations are analyzed. Furthermore, the combined effects of side stream maldistribution are investigated for different inlet Reynolds numbers and inlet temperatures. The results demonstrate that when the inlet gas Reynolds number is in the range of 1100–2700, nonuniform distribution of the gas side will cause air maldistribution, and a 10%–30% effectiveness deterioration rate. It is found that air maldistribution will not result in gas maldistribution when the inlet air Reynolds number is in the range of 6000–18 000, but increasing air nonuniformity. Will lead to increasing deterioration in heat exchanger effectiveness. In the presence of air and gas flow maldistribution, the pressure drops on the gas and air sides increase by 5% and less than 12.4%, respectively. This work provides a computational framework for optimization of cross-flow-corrugated plate heat exchangers to achieve desired thermo-hydraulic performance.