Development Of Plate Beam Roller Straightening Equipment For Plate-fin Heat Exchanger And Straightening Process Research

Heat exchanger is a kind of equipment that promotes energy exchange between different media through special internal structure.It is widely used in petrochemical industry,heat exchange equipment,home appliances,vehicles,refrigeration,power engineering and machinery.The core component of the heat exchanger is a plate bundle,which is a place for energy exchange between media.Different numbers of plate bundles are assembled by brazing and other processes,and the periphery is equipped with medium circulation pipes and joints and related supports to form the basic form of the heat exchanger.The material of the plate bundle parts is usually made of aluminum alloy.The surface of the aluminum alloy is covered with a special coating.The coating melts under the action of high temperature in the brazing furnace,and the fins and the upper and lower cover plates are welded together.Affected by factors such as unstable fin forming quality and poor flatness of upper and lower plates,the plate bundle will produce a central depression after vacuum brazing,which results in poor product flatness,and the flatness detection is brazing The important content of the quality inspection of the bundle after welding.Poor straightness will cause problems such as large gaps in the side-by-side assembly of the bundle and poor welding,which will seriously affect product quality and bring huge economic losses to related companies.Therefore,it is necessary to straighten the plate bundle with poor straightness,and there are many factors that affect the straightness after straightening,so it is of great significance to analyze the heat exchanger plate bundle straightening process.This paper studies the straightening mechanism of the heat exchanger plate bundle direction.The research content and results are as follows:(1)According to the main structural form of the parallel roller straightening machine and the performance requirements of the plate bundle straightening,the overall scheme design of the plate beam automatic straightening,packaging equipment structure and control system is carried out.Calculate the roll diameter,roll distance,roll number,and straightening torque parameters of the roll straightener,design the test prototype based on the calculated parameters,and perform the plate bundle straightening test.(2)The finite element model of the plate beam straightening process was established,and the straightening test was carried out using a physical prototype to verify the accuracy of the finite element model.Analyze the evolution of stress and strain during straightening and the horizontal and vertical paths of the plate bundle during post-processing,and study the reduction of the straightening process parameters,the initial arc height of the plate bundle and the straightening speed.The influence law of residual stress and plastic strain after straightening provides guidance for how to select plate bundles with different bending degrees in the actual straightening of plate bundles.(3)Multi-index orthogonal test is constructed by parameters such as straightening arc height,percent change in arc height before and after straightening,residual stress after straightening,etc.to analyze straightening roll pitch,upper roll reduction,straightening speed,and plate bundle initial arc The main influencing factors of high influence on the straightness and residual stress of the straightening of the plate bundle.According to the actual production requirements,the best combination of the straightening process parameters is synthesized,and the plate bundle straightening test is designed to verify and improve the plate.The quality of beam straightening provides a theoretical basis.