Heat transfer enhancement investigation in a novel flat plate heat exchanger

Plate heat exchangers (PHEs) have become the most popular type of heat exchangers (HEs) for a wide range of daily applications due to their compactness and high thermal performance. The present study aims to expand the understanding of the thermal performance of the basic flat PHE (FPHE) and to develop a more efficient FPHE as well. A new flow arrangement is proposed in order to enhance the thermal performance of the FPHE (modified FPHE). The new flow mechanism is fulfilled by changing the design of the gasket where the inlet and the outlet ports are located on the same side of the thermal plate. Computational fluid dynamics (CFD) has been used to conduct the numerical simulations. The overall simulations have been performed on two FPHEs; the basic and the modified one. Both HEs have identical geometrical dimensions and physical test conditions. Nusselt number (Nu), Stanton number (St), Colburn factor j, friction factor (f), and JF factor are employed to evaluate and compare the thermal performance of the presented HEs. Heat transfer data are collected for single phase (waterwater), and for Reynolds number (Re) spans from 250 to 2000. The numerical findings have been validated with benchmark experimental data from the literature. The results show that, Nu and f data of the modified FPHE are respectively up to 70% and 4.4 times those of the basic FPHE. The critical Reynolds numbers (Recr) for the modified FPHE are identified. Moreover, JF data of the modified FPHE shows similar to 0.7%-9% enhancement in the thermal performance with respect to the basic FPHE, hence it could save material and energy for the same heat duty. The findings of the present study have also developed the corresponding correlations for the Nu and f for all cases.

Automated summary

This study aims to enhance the thermal performance of the basic plate heat exchanger (FPHE) by proposing a new flow arrangement. Computational fluid dynamics simulations show that the modified FPHE has significantly higher Nusselt number and friction factor compared to the basic FPHE.