Development and Implementation of CO and HC Emission Models for use in an

Integrated Diesel Engine, Emissions and Aftertreatment System Model

Nilesh L. Bagal

Advisors: Prof. David E. Foster & Prof. Christopher J. Rutland

GM UWCollaborative Research Lab

Engine Research CenterUniversity of Wisconsin-Madison

Integrated System Model

Current Integrated System Model includes: -

Emission models (Indranil Brahma) NOx and Soot Model

Exhaust system models (Dave Kapparos) After-treatment device models (Andrea Strzelec) Integration of above models (Stephan England)

It lacks: - Emission models

Carbon Monoxide (CO) and Hydrocarbons (HC) Model

GM UWCollaborative Research Lab

Objective

Study the chemical kinetic of CO and HC formation in diesel engine Study the various engine parameters affecting production of CO and HC Develop a phenomenological Zero-D CO and HC emission model Explore use of Neural network weights to optimize the phenomenological model

Validate the model with the experimental data

Implement the model in the Integrated System Model

GM UWCollaborative Research Lab

CO Formation

GM UWCollaborative Research Lab

Sources of CO formation

Over mixing of fuel Occurs in conventional diesel combustion Due to low peak combustion temperature Associated with lean combustion during ignition delay period

Under mixing of fuel Product of rich premixed combustion CO fails to mix with sufficient O2 to complete oxidation CO formation is function of chemical kinetics

Rate of oxidation of CO is slow as compared to other hydrocarbons Thus CO lags behind in oxidation even with the presence of O2

Literature Review CO model by Ricardo

CO model by Arsie et al. SAE 980779

GM UWCollaborative Research Lab

HCOOHCO 2

222

1COOCO

OH

H

KOPKCO

CO

pp)4(

1

)3(

1max

22 Kp (3), Kp (4) from Newhall (1968)

HCOOHCO 2

2OCOOCO

eCO

CORR

dt

COd1)( 21

R1 and R2 defined from forward and backward rate constants

Literature Review “The effect of Swirl Ratio and Fuel Injection Parameters on CO Emission and Fuel Conversion Efficiency for High-Dilution, Low Temperature Combustion

in an Automotive Diesel Engine”By Kook et al. SAE 2006-01-0197

GM UWCollaborative Research Lab

Studied the impact of swirl level and injection timing on CO emission An optimal swirl ratio exists at which lowest CO is observed CO emissions decrease as SOI is advanced This is due to enhanced pre-combustion mixing CO oxidation rates are not a significant factor influencing peak in-cylinder CO mass