Investigation On Plate Heat Transfer And Resistance Characteristics And Stamping Process Of Plate Heat Exchangers

Plate heat exchanger is a novel heat exchanger with high efficiency, which is composed of a series of corrugated plates. Plate heat exchanger is widely used in the fields of petroleum, energy, etc. Plate is the "soul" of a plate heat exchanger, and its structure and the corrugated shape will determine the heat exchanger’s heat transfer characteristics, resistance characteristics and performance under pressure. In addition, the stamping quality of plate is of great importance to the assembly effects and the performance of other aspects. Therefore, design and optimization of the plate’s shape and its forming processes has important theoretical significance and practical value.In this paper, the plates of triangle-boss plate heat exchanger were studied, and a numerical simulation model of plate heat transfer process was established. The influence of the plate’s shape parameters on the liquid flow pattern, plate heat transfer and resistance characteristics was analyzed in detail. A comparative study on the heat transfer, resistance characteristics and performance under pressure of triangle-boss plate with pits and without pits was conducted, and the variation pattern of the stamping quality of plate with process and molding parameters was discussed.Regional models of several groups of triangle-boss plate with different boss heights and radii of circular bead at the top of the boss were established with Fluent, a CFD software, and the velocity field, temperature field and pressure field of the fluid in each group were obtained. The variation pattern of heat transfer parameters, such as Nusselt number and heat transfer factor under different Reynolds numbers were analyzed, and the influence of boss height and radii of circular bead at the top of the boss on heat transfer characteristics and resistance characteristics was revealed. By fitting the numerical simulation result data, triangle-boss plate’s heat transfer criteria equation containing the two plate parameters was obtained.The numerical simulations of heat transfer of triangle-boss plate with pits and without pits were conducted, liquid flow patterns and the Nusselt numbers, heat transfer factors, friction factors under different Reynolds number in the two flow passes were obtained, and a comparative analysis on the heat transfer and resistance characteristics of the two kinds of plates was conducted. A analysis about the stress and strain on regional model of the two kinds of plates was conducted with ANS YS Workbench, the influence of pits on the boss on stress and strain distribution of plates was revealed, and a comparative study on the performance under pressure of the two kinds of plates was conducted.The numerical simulation of stamping process and springback analysis of triangle-boss plate with pits were performed, and the distribution of thinning and warpage deformation after forming process was revealed. The influence of blank holder force, mold clearance, stamping velocity and friction coefficient on the plate’s thinning and warpage deformation was summarized by orthogonal test, and effective measures of suppressing thinning and warpage deformation and improving the plate’s forming quality were proposed.