Numerical Simulation Of Gas Flow In The Annular Cooler And Waste Heat Recovery System Optimization

The cooling process of the sinter occurs in the rotating annular cooler, namely annualcooler. The annular cooler is an important device of the sintering process in iron and steelindustry, adopting segmented blast cooling method and achieving the purpose of coolingthrough the heat exchange occurred between the cold air blew from the bottom of the bellowsand the hot sinter in the trolley. A large number of applications in the heat power generationproject of annular cooler waste gas have been widely used both at home and abroad withoperation and improvement of the ring cooler solely concentrating on past engineeringexperience, but being lack of systematic research and analysis. Moreover, it’s not common asfor the numerical simulation of the internal cooling process. Therefore, based on the projectestablishment of physical and mathematical model of the annular cooler, the thesis aims toconduct a further research and explore the process of fluid flow, heat and mass transferintegrated with scientific measures to obtain the relevant parameters of the flow field, thermalprocesses for the purpose of explaining some related phenomena and finally guiding theengineering practice.This study is targeted at a 360m2annular cooler research carried out by a localore-sintering plant and introduced the development and technological characteristics of theannular cooler, based on which it set up a physical model of the annular cooler with practicalsize, built a mathematical model of fluid flow and designed the sintering thermal process inthe annular cooler. Both structured and unstructured grid were utilized in discreting thecomputational domain.Assuming that the sinter was a porous media model and selecting the turbulent flow instandard k-εtwo-equation model, the thesis designed to simulate pressure and velocity vectordistribution of the fluid flow and the temperature distribution of the sinter cooling in a singlebellows section with the instrument of the FLUENT computational fluid dynamics software.In the view of the existing waste heat recovery heat power generation projects from thesensible heat of sinter, the thesis conducted with combination of simulation results, analysis offluid field with the improvement on circulation of hot air and segmented recovery, discussion of the optimized scheme was achieved. The main findings are:1) Obtain the flow field distribution in Annular cooler; the average velocity fluid flowrate is about 0.01 m/s in the material layer of the sinter, the velocity in the hoodcover the range of 3 m/s;2) The cooling fluid get through the sinter as the form of jet stream, and are notuniformly distributed in the bottom of the bellows;3) For dividing line in sinter bed, velocity of the fluid is gradually decreasing along thecoordinate Z axis positive direction (vertical direction) in the zone of the bellows;velocity of the fluid damps rapidly; when fluid through the sinter, the velocity isincreasing (pressure is opposite) and the gradient is relatively large;4) Most of the isotherms in the cooler showed upward convex, and tends to level thesurface of the upper and lower material layer;5) Flue gas segmented recovery can exacerbate the disturbance of the fluid in the hood,enhancing the heat transfer; circulation system of hot air can improve the thermalexhaust gas temperature about 30℃, increasing the heat flux.