Dynamic individual-cylinder analysis of a Gasoline Direct Injection engine emissions for cold crank-start at elevated cranking speed conditions of a Hybrid Electric Vehicle
Document Type
Article
Publication Date
12-2022
Department
Department of Mechanical Engineering-Engineering Mechanics
Abstract
The cold crank-start phase significantly contributes to the engine-out total emissions during the US Federal Test Procedure (FTP). A Gasoline Direct Injection (GDI) engine dynamics and emissions are investigated during the first three engine cycles of the cold crank-start in Hybrid Electric Vehicle (HEV) elevated cranking speed at 20 °C. To this end, the impact of the operating strategy on the individual-cylinder engine-out emissions is analyzed quantitatively. For this purpose, a new dynamic method was developed to translate the engine-out emissions concentration measured at the exhaust manifold outlet to mass per cycle per cylinder. The HEV elevated cranking speed provides valve timing control, throttling, and increased fuel injection pressure from the first firings. This study concentrates on analyzing the cranking speed, spark timing, valve timing, and fuel injection strategy and parameters effect on engine-out emissions. Design of Experiment (DOE) method is used to create a two-step multi-level fractional-factorial test plan with a minimum number of test points to evaluate the significant parameters affecting engine-out emissions during cold crank-start. Out of the first step DOE analysis, the optimal cranking speed, spark timing, and valve timing, which results in the lowest unburnt HydroCarbon (HC) and NOx emissions, are distinguished. Then, fixing the first step parameters at their optimal values, the second step is accomplished with the fuel injection parameters sweep. The split injection parameters, including the Start of the first Injection (SOI), End of the second injection (EOI), and split ratio (SR), in addition to the first cycle additive fuel factor, are investigated. Results show that the high cranking speed with stabilized low Manifold Absolute Pressure (MAP), highly-retarded spark timing, high valve overlap, late intake first injection, 30 CAD bTDC firing EOI, and low first cycle fuel factor reduces the HC emissions 94%.
Publication Title
Control Engineering Practice
Recommended Citation
Khameneian, A.,
Dice, P.,
Duncan, J.,
Naber, J.,
Shahbakhti, M.,
Archer, C.,
&
et al.
(2022).
Dynamic individual-cylinder analysis of a Gasoline Direct Injection engine emissions for cold crank-start at elevated cranking speed conditions of a Hybrid Electric Vehicle.
Control Engineering Practice,
129.
http://doi.org/10.1016/j.conengprac.2022.105349
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/17311