An Experimental Study On SCR System Of Diesel Engine To Reduce NO_x Emissions

The Annexes to MARPOL73/78 of International Maritime Organization restricts the SOx and NOx emissions. Until 2016,the emissions of low speed engines will be reduced from 17.0 g/kWh to 3.4 g/kWh and the high speed engines from9.8 g/kWh to 1.96 g/kWh. In-engine cleaning technologies has become increasingly with the more stringent emission regulations.It must be took an aftertreatment technology to reduce NOx emissions. SCR technologies is accepted the best way currently,and it is also ripe in European diesel engines.SCR system means Selective Catalytic Reduetion exhaust aftertreatment system.It can effectively reduce the NOx emissions on the flow rate, temperature and components changeful reaction environment, without changing the engine fuel consumption and inner structure.In this paper, the author introduces with detail the preparation of TiO2-WO3-V2O5 catalyst, and develop a urea injection system and design of SCR reactor on the basis of type 6106 of the diesel engine. The bench test is performed on 6106 diesel engine to validate the conversion efficiency of SCR system. The result shows that the NOx efficiency of converting comes to 50%～60% at 350～500℃, while the space velocity is 60000h-1.The exhaust back-pressure is slightly increased and fuel consumption increased less than 1%. Based on the analysis of the design and experiment, it proposed to improve the direction of SCR system, which provides reference to the further optimization design of the catalyst.