Multi-objective Optimization Design Of Demister With Built-in Baffle In Tube Row

In recent years,the aggravation of haze affects people’s hearts,and the flue gas discharged from thermal power plants after wet desulfurization carries a large number of fog droplets.The existence of fog droplets promotes the generation of PM2.5 in the air.The demister can effectively Remove the droplets carried in the flue gas.Although the wire mesh defogger has great defogging efficiency,it is prone to blockage and secondary carryover,and has a large pressure drop;the cyclone defogger has a complex structure and large resistance;the folded plate defogger Because of its simple structure,low cost,low pressure drop and easy cleaning,it is widely used.However,the mist eliminator has a very poor defogging effect on droplets with a particle size of less than 20 μm.Therefore,this paper designs a folded-plate defogger with built-in tube row,that is,the structure of the folded-plate defogger is modified by adding tube rows to form a folded-plate defogger with built-in tube row,and adopts response surface method and genetic algorithm.Combined with the optimization of the demister.Through the numerical simulation and comparative analysis of the folded plate defogger,the folded plate defogger with hook plate,and the tube row built-in folded plate defogger,it is concluded that the tube row built-in folded plate defogger has a particle size less than 20μm.The collection efficiency of the defogger is significantly higher than that of the folded plate demister with hook plate and the folded plate demister,followed by the folded plate demister with hook plate,and the last is the folded plate demister.In the case of a constant inlet flow rate,the tube row built-in folded-plate mist eliminator,the folded-plate mist eliminator with hook plate,and the folded-plate mist eliminator have a positive correlation between the maximum collection efficiency of droplets and the particle size of the droplets..The maximum collection efficiency of the folded-plate demister with built-in tube row is far greater than the maximum collection efficiency of the folded-plate demister with hook plate and the folded-plate demister,and they are generally concentrated in the two bends of the demister.Under the circumstance that the other structural parameters of the built-in folded plate defogger in the tube row remain unchanged,a single change of a certain structure of the defogger shows that the tube diameter,the number of tubes and the turning angle are positive for the defogging efficiency and pressure drop.Correlative effect,and the plate spacing has a negative correlation with the defogging efficiency and pressure drop.Through the use of response surface method and genetic algorithm to carry out multi-objective optimization design of the tube row built-in folded plate defogger,it can be known that the genetic algorithm is used to maintain the same pressure drop and the same inlet flow rate.The defogging efficiency of the optimized defogger is greater than the defogging efficiency of the originally designed defogger,and while maintaining the same inlet flow rate and the same defogging efficiency,the optimal solution obtained after the genetic algorithm optimization is less than the original design The pressure drop of the mist eliminator.