Numerical investigation of three methods for improving heat transfer in counter-flow heat exchangers

The present study investigates the thermal performance and fluid characteristics of counter flow heat exchangers (CFHEs) computationally. Increasing heat transfer rate in heat exchangers depends on various parameters such as channel geometry, the geometry of obstacles in the channel, frequency and amplitude of corrugated plate, and other factors. In this simulation, the influence of parameters contains the effects of the geometry of the obstacles, the corrugated plate between the channels, the elastic plate between the channels, the frequency and wavelength of the corrugated plate, and its effect on increasing the heat exchanger efficiency have been studied in detail. The numerical method is the finite element method, and a complete set of Navier-Stokes equations are solved unilaterally using the Petrof-Galerkin method. It has been concluded that all methods will improve the performance of the CFHEs. Among the obstacles placed in the channels, the rectangular and edge obstacles show better results. In the case of a corrugated mid-plate, with increasing the wave in mid-plate between channels, heat transfer rate (HTR) increases to a certain amount. It was observed that the elasticity of the mid-plate between two channels and the sinusoidal pulse flow would improve HTR in CFHEs.