Heat transfer augmentation in retrofitted corrugated plate heat exchanger

摘要

Corrugated plate heat exchangers (CPHEs) have been extensively adopted especially for systems that require high thermal efficiencies such as aerospace and gas turbine power plants. According to several factors (i.e. required heat duty), CPHEs can be optimized to meet the application requirements. However, the number of the required thermal plates (N_p) could be very large (N_p＞40) which in turn would cause several disadvantages (i.e. sever flow maldistribution). Therefore, the present study aims to introduce an innovative modification that can boost the thermal performance of the basic CPHE which in turn would reduce the number of required plates for the same heat duty. The thermal performance of the modified CPHE has been numerically investigated by using Computational Fluid dynamics (CFD) software. The numerical data have been validated with experimental measurement from the literature. The impact of the new modification has been studied on Nusselt number (Nu), fanning friction factor (f), Stanton number (St), Turbulence kinetic energy (TKE), flow maldistribution, j factor, and quality index factor (JF). The result has been compared with previously reported data of the basic corrugated and flat PHEs. At the same mass flow rate, Nu, f, and TKE of the modified CPHE are respectively 1.3, 1.7, and 3.5 times greater than those of the basic CPHE. Moreover, JF data of the modified CPHE are 1.4, and 64 times greater than those of the basic corrugated and flat PHEs, respectively. In addition to the superior thermal performance, the present modification offers larger contact area between the plates which could boost the overall mechanical integrity of the heat exchanger. Thus, this modification could pave the way for CPHEs to be incorporated in new applications that require more compact and durable Hes. The heat transfer correlations of the modified CPHE have been developed.