某型船用柴油机排放优化过程分析

Analysis of Emission Optimization Process for a Certain Type of Marine Diesel Engine

以某型大功率共轨柴油机主机为样机,研究了共轨柴油机的排放标定策略,标定过程中发现该机经济性良好,但排放水平较差,保持高轨压降低正时时,烟度迅速升高。通过分析试验数据,认为样机进气流量不足,因而重新匹配了3款增压器,流量依次增大。匹配试验过程中保持环境参数和柴油机状态不变,通过对比样机和3款增压器的试验数据,发现提高进气量大幅改善了低正时下的缸内燃烧状态,NOx生成量变化不大而烟度大幅降低。在增压器3的状态下重新进行了排放标定,与样机相比,NOx降低了11%PM降低了54%满足了船机国标一阶段限值要求。

Taking a certain type of high-power common rail diesel engine as a prototype,the emission calibration strategy of the common rail diesel engine was studied.During the calibration process,it was found that the engine was really economical,but the emission level was poor.When the high rail pressure was maintained and the injection timing was reduced,the smoke level raised rapidly.Through analyzing the test data,it was considered that the intake air flow of the prototype is insufficient,so three turbochargers were re-matched,and the flow increased successively.During the matching test,the environmental parameters and the diesel engine state were kept unchanged.By comparing the test data of the prototype and three turbochargers,it was found that the increasing of the intake air flow greatly improved the combustion state in the cylinder at low injection timing,with little change in the amount of NOx generated and a significant reduction in smoke.In the state of turbocharger 3,the emission calibration was carried out again.Compared with the prototype,the NOx was reduced by 11%,and the PM was reduced by 54%,which met the first-stage limits of national standard for exhaust pollutants from marine engines.