Optimization Design Of Flue Deflector Structure In Spray Tower Based On Field Synergy Theory

Spray tower is now a widely used essential equipment for flue gas desulfurization.Flue gas flow field can affect not only the efficiency of desulfurization when flue gas flows through spray level,but also the efficiency of demist when flue gas flows through the demister.Lacking in efficiency of desulfurization,the sulfur in tail flue gas can't achieve the emission standard;lacking in efficiency of demist,a large amount of plaster slurry carried in the flue gas would be charged into the atmosphere through the chimney.This would easily form Gypsum rain at the tail of the chimney,which can badly harm the environment.As a result,the gas-liquid two phase flow field in the spray tower has significant influence on the actual efficiency of inner equipment,which motivates the research of practical devices.Currently,there are mainly two ways in optimizing the flue gas flow field in spray tower:improving the flue structure and setting deflectors.Based on the previous study and projects experience,setting deflectors can certainly improve the inner flow field of flue gas.While the problem is that there is none general guidance for designing deflectors so far.In horizontal projects,the improvement either counts on the comparison of large amount of numerical simulation results,or refers to previous design experience.This is rather time consuming and laborious,optimization effect is still unpredictable.In response to these actual projects' demand,this thesis focuses on the following three aspects:Firstly,field synergy principle is introduced.This thesis considers the additional volume force deducted from field synergy equation as a source term,and implement it into FLUENT momentum equation in way of compiling user-defined-functions(UDF)to complete the numerical simulation.In this way,we can obtain an ideal flow field.Then this thesis utilizes part of the streamline to design flow field optimization component-deflectors.Results of optimization effect are very promising.Secondly,this thesis takes Huaneng Anyuan Power plant's "developing large units and suppressing small ones" new construction projects as research object.Combined with last chapter's conclusion of new optimization method,this thesis starts to optimize the inner flue gas flow field of spray tower,aiming at achieving required flow uniformity of critical area.Then this thesis compares this new method with traditional deflectors design method.It proves that flow field synergy principle can indeed provide guidance for designing deflectors,and the optimization effect proves to be better than traditional ways.Thirdly,this thesis takes research project on flow field simulation of a new ultra supercritical coal-fired power plant of Jia Huwean.Based on previous chapters' conclusions,this thesis directly computes the ideal flow field added with field synergy equation.Then this thesis obtains one of the streamlines' coordinates to design proper deflectors.In this way,the concerned critical flow field is optimized to project demand.