Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6632302 | Fuel | 2018 | 13 Pages |
Abstract
In this study, the combustion and emission characteristics of a turbocharged GDI engine under cold start NEDC were investigated based on chassis dynamometer test. The operating states, combustion and emission performance of GDI engine were measured continuously during vehicle driving cycles. Then, the combustion and emission characteristics of GDI engine under cold start NEDC were obtained and the influence factors were revealed by synchronous analysis of various operating parameters. The results show that, the combustion duration from start of combustion (SOC) to 50% combustion location changes a little under cold start NEDC. At most time, the 10-90% combustion duration usually changes in the range of 20-40â¯Â°CA, which turns longer under idling conditions but shorter under acceleration conditions. Since the sparking timing is severely retarded in the beginning stages of NEDC, the effect of cold start on hydrocarbon (HC) emission is very limited. HC emission increases sharply under deceleration conditions, due to the decrease of engine indicated mean effective pressure (IMEP). Carbon monoxide (CO) emission does not seem to have relevance to the cold start condition, and it is very sensitive to excess air coefficient while the effects of other parameters are very little. Nitrogen oxide (NOx) emission increases under acceleration conditions but decreases under deceleration conditions, which is mainly influenced by the IMEP, then followed by engine speed. All those not only demonstrated the change rules of combustion and emission characteristics of turbocharged GDI engine under cold start NEDC, but also provided the guidance for improving the vehicle emission performance.
Keywords
aTDCIMEPTWCVVTWLTCcadCTDCNEDCPFIRGFGDIWLTPUDCEGREUDCDCGExtra Urban driving cycleLPGThree way catalystsbTDCNOxinternal combustionEmissionResearch Octane Numbernitrogen oxideafter top dead centerport fuel injectiongasoline direct injectionspark ignitionparticulate matterRONVariable valve timingSOCStart of combustionbefore top dead centertop dead centercarbon monoxideIndicated mean effective pressurehydrocarbonCombustion characteristicsUrban Driving Cyclenew European driving cycleResidual gas fractionliquefied petroleum gasexhaust gas recirculation
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Guohui Zhu, Jingping Liu, Jianqin Fu, Zhengxin Xu, Qiyi Guo, He Zhao,