Study Of Marine Diesel Engine Emissions Standard Of IMO-T3

With the increasing environmental pollution, the emissions regulations for harmful pollution are stricter. The international maritime organization (IMO) MAPPRO protocol dictates, and marine diesel engine must meet local emission regulations of port、coastal or inland areas. These local regulations tend to be stricter than the second grade of the IMO. IMO third grade T3 for NOX emission limitation value is the strictest.Different EGR rate leads to different air-fuel ratio, affecting the engine fuel economy and emission performance. Usually different camshafts need to be matched with different turbochargers. The simulation software GT-Power for diesel engine is used to divide pipeline of geometry graphics, design the model, optimize the opened Angle, analyzed the influence of different EGR rate on NOx emission. In the development of engine performance, different injectors, turbo-chargers, fule pumps, EGR camshafts and combustion chamber are used to reduce NOx. But it still can not meet the regulations requirement of the IMO-T3.Compared with the road vehicle’s SCR system, Marine SCR system changes a lot in the the operation and structure layout. Design the Marine SCR scheme before or after the turbine based on catalyst conversion efficiency and engine using characteristics, then choose the SCR scheme after turbine based on the diesel engine using characteristic. Using CFD software to calculate different urea aqueous solution under the arrangement of the particle trajectory, the average speed and so on, and it can meet the requirements according to the results. SCR calibration can optimize the engine performance. Jet pump calibration must be carried out before test and a certain range of deviation is permitted. The calibration work is very important, it can make meet the regulations requirement of T3 emissions with reduced cost.