Numerical Simulation Of New Combined Desulfurization, Denitrification And Demercuration Tower With Active Coke

The combined-removal technique is usually using two sets of devices in ournation, which obviously increases investment and operating costs, so the study ofmulti-removal technique in one unit becomes a trend. Obviously, the new combineddesulfurization, denitrification and demercuration tower with active coke is of greateradvantage and more broad application prospect due to the combined-removal of NOx、SO2and heavy metal pollutants such as mercury in coal-fired flue gas.Based on Fluent software, the new combined desulfurization, denitrification anddemercuration tower with active coke was simulated and optimized using the k-εturbulence model, the porous medium model and SIMPLE algorithm. The studyincluded three parts. Firstly, the smoke motion trance of the entrance, the velocityuniformity through active coke and the pressure drop of the whole tower wereanalyzed with numerical simulation when installing different types of deflectors. Theresults showed the deflectors prevented the impact on the wall. Moreover the velocitywas more uniform and the pressure was smaller with the curved deflectors than thatwith the straight or the stepped. Meanwhile the flue gas that through the active cokewas the most homogeneous when the length of curved deflectors extended to3.6m.Secondly, based on the component transport model, ammonia distribution, vortexintensity and pressure drop in the ammonia mixing zone were analyzed withnumerical simulation for the different arrangement of turbine mixers. The resultsshowed vortex intensity was the most intensive when the ammonia injection pipediameter was75mm and scroll plate was placed at45°, which was consistent with theconclusion that the ammonia distributed uniformly most. But the pressure drop waslargest. At last, the pressure of active coke was researched by experiment, meanwhilethe experiment value and simulation was contrasted. It was found that when the heightof active coke was small, the relation between the flow rate and pressure was linear,but when the height was enough, the relation between them was quadratic function.When the flow rate was a certain, the relation between the filling height and pre ssurewas linear, and the greater the flow rate, the greater the slope of linear relationship.Furthermore the simulation data agreed with experiment data, and the feasibility ofthe porous medium model was verified.