Research Of Soot Blowing For Two-stroke Marine Diesel SCR

In the selective catalytic reduction(SCR)system,the soot blowing result of catalyst is directly related to NOx conversion rate,engine performance,catalyst life.Due to limited space of the engine room,the soot blowing piping arrangement in compacted designed SCR reactor is difficult,this problem is particularly prominent for the two stroke marine diesel engine.To achieve effective soot blowing of catalyst at lower cost is the main research direction.The paper use computational fluid dynamics(CFD)commercial software FLUENT characteristic of single soot blowing hole,characteristic of multiple soot blowing holes on one plate,characteristic of multiple soot blowing holes on pipe.Cleaning of catalyst can be obtained with proper soot blowing piping arrangement for the reactor.Firstly,change law of effective cleaned area and air consumption under different soot blowing hole's diameter and compressed air pressure is studied by studying the characteristic of single soot blowing hole.The optimal soot blowing hole's diameter is 1mm and the optimal distance between soot blowing holes to the inlet surface of catalyst is 180mm.The compressed air pressure range is limited to 5?15bar.Secondly,the rule of interaction is studied by studying the characteristic of multiple soot blowing holes on one plate.Three layout of multiple soot blowing holes are designed.Thirdly,the optimal solution is determined by comparing the three different layout of multiple soot blowing holes on pipe.The optimized angle between soot blowing holes is 60? and optimal the compressed air pressure is 10?13bar.With structure of the reactor,additional layout of multiple soot blowing holes on pipe is designed on the position which is close to shell of reactor.And the optimized angle between soot blowing holes is 20°.Finally,the air consumption are calculated according to final arrangement of soot blowing piping arrangement.The diameter of soot blowing pipe which is close to shell of reactor is DN32,the other pipe diameter is DN25.The main pipe diameter is DN100.According to the SCR reactor test bed condition,the final compressed air pressure is 10bar and the strategy of soot blowing are determined.