Hydraulic measures to improve common-rail injection system performance - Impact of injection rate shaping on emissions of a medium speed diesel engine
The introduction of IMO-TIER III in 2016 demands a reduction of NOx-emissions by 75% compared to IMO-TIER II. This cut in emissions is only to be achieved by applying new technologies to ship diesel engines. One promising option to reduce emissions by engine internal measures is the introduction of exhaust gas recirculation (EGR). In order to control particulate emissions as well as fuel consumption, this technology can only be applied when significantly improving the fuel injection system at the same time. The presented work focuses on the impact of injection rate shaping on the emissions of a medium speed diesel engine. The approach is based on the idea to generate very specific injection rates, which are referred to have a positive effect on engine emissions, by simple hydraulic considerations. Therefore, the existing common-rail injection system of the medium speed research engine 1 VDS 18/15 has been modified and extensively tested. The engine measurement results show that injection rate shaping significantly influences engine emissions. In certain points, reductions of particulate emissions of up to 70% compared to a reference set-up were achieved at constant NOx while even providing advantages in indicated engine efficiency. It is shown that especially at 50% load conditions a RAMP-like injection rate does offer the highest potential. On the other hand no advantage is detected for the given conditions at 75% engine load. These results are confirmed by cylinder pressure traces showing how rate shaping influences the premixed and diffusive combustion phase. Based on the engine results it has to be stated that hydraulic measures to control injection rates can have a considerable potential to reduce engine emissions. The possibility to influence the combustion process by applying injection rate shaping allows a fundamental analysis of combustion parameters with respect to emission generation. The presented work so provides an important basis to improve the understanding of emission generation processes in large diesel engines.
Christian Fink Martin Drescher Jean Rom Rabe Horst Harndorf
University of Rostock,Germany FVTR GmbH,Germany
国际会议
上海
英文
1-10
2013-05-13（万方平台首次上网日期，不代表论文的发表时间）