Thermal Performance Analysis of Conventional and Enhanced Corrugated and Flat Plate Heat Exchangers

University of Technology Sydney. Faculty of Engineering and Information Technology.Plate heat exchangers (PHEs) have been extensively adopted for a large number of industrial applications, particularly systems that require high thermal efficiencies such as aerospace and heat recovery applications. Several studies have been performed on PHEs to disclose the impact of different geometrical parameters on heat transfer characteristics. However, the demand for energy is continuously increasing, and there is continuous development in industrial processes that require newly developed compact heat exchangers (HEs). Therefore, this thesis aims to introduce enhanced corrugated and flat PHEs. Passive enhancement techniques are adopted. Computational fluid dynamics (CFD) has been utilised to verify the superiority of the proposed enhanced PHEs. All turbulence models have been tested, and realizable − with scalable approach for wall treatment is found the best model that could provide the most accurate data. All PHEs that have been studied in the present thesis have identical geometrical and physical parameters. Full CAD approach is used, and all geometrical parameters are considered i.e. port effect and sinusoidal corrugations shape. The numerical approach has been extensively validated with benchmark studies from the literature, and an experiment is conducted for further validation. All studies are performed for water-water, 1-1 pass, U type, and counter-current flow arrangements. To assess the thermal performance of the enhanced PHEs, the findings have been compared with those of the conventional PHEs. Nusselt number (Nu), and fanning friction factor (f) are utilized as indicators of enhancement in the convective heat transfer and pressure drop, respectively. Moreover, turbulence kinetic energy, turbulence intensity, JF factor, intensity of flow maldistribution along with other parameters, are also employed to compare the thermal performance of the enhanced PHEs against the conventional ones. Generally, the thermal performance of the proposed corrugated and flat PHEs unequivocally outperforms that of the conventional PHEs. For instance, the enhancement in Nu data of the modified PHEs are up to 75%, 70%, 30%, and 175% with respect to the conventional PHEs. Hence the selection of the enhanced PHEs must be carefully performed, e.g. based on allowable pressure drop. Overall, these enhanced PHEs could pave the way for more compact HEs to be built and incorporated in applications that require more compact and durable HEs. They could be potential replacements of their counterparts of PHEs. In all studies, heat transfer correlations have been developed to assist the designers in predicting the HEs’ thermal performance and to estimate the required heat transfer surface area