Study On The Measurement And Calculation Of Emission From Marine Diesel Engine

For IMO new Technical Code on control of emission of nitrogen oxides from marine diesel engines, the thesis introduced the differences between the old and new edition of NO_X Technical Code about emission measurement and caculation methods in detail. Then the emission results obtained according to the old and new edition of calculation methods were comparised and analysed through the bench tests of marine diesel engine. At the same time the Contrastive analysis of the emission results of different measurement cycle was carried out, aiming at discussing the differences of different level of emission restrictions and emission measurement cycle, and found the key modes of controlling the emission of marine diesel engine through analyzing emission ingredient weight.The results showed that comparing with the new and old edition of calculation metholds, there were some improvements on the emission measurement and certification. In the aspects of emission calculation, the exhaust gas mass flow and the NO_X humidity correction factor and dry to wet correction factor had been improved.The emission results which were calculated by different measurement cycle of marine diesel had little difference. According to the emission ingredient weight analysis of diesel engine, the way of reducing the emission level of diesel engine was to control the mode points whose emission ingredient weight are larger than others. The sixth and eighth mode point should controlled for thirteen test cycle,as the second mode point for E3 test cycle and the second and third mode point for D2 test cycle.In this paper, combining with new edition of NO_X emission calculation method, the influence of the measurement deviations of CO₂ dry concentration, fuel composition and mass flow and air condition on emission results was analysed. Based on the amendment of MARPOL convention Annex VI, this thesis introduced several methods of marine diesel engine real ship emission test, and emphatically expounded real ship measurement scheme of Main Engine and Generator Engine. Then discussed the rationality of real ship simplified test cycle option A～G which were put forward in new editon of NO_X Technical Code. Meanwhile, the experiment of real ship emission measurement was carried for the G.E.of ocean ship, and the emission results got according to the old and new calculation metholds were comparised and analysed.In conclusion, the thesis focused on the study of the emission of marine diesel engine. The relevant reserch results obtained had some degree of guiding significance for the development of emission testing technique of marine diesel engine.