Gasoline engine performance simulation of water injection and low-pressure exhaust gas recirculation using tabulated chemistry
Journal article, 2020

This work presents the assessment of direct water injection in spark-ignition engines using single cylinder experiments and tabulated chemistry-based simulations. In addition, direct water injection is compared with cooled low-pressure exhaust gas recirculation at full load operation. The analysis of the two knock suppressing and exhaust gas cooling methods is performed using the quasi-dimensional stochastic reactor model with a novel dual fuel tabulated chemistry model. To evaluate the characteristics of the autoignition in the end gas, the detonation diagram developed by Bradley and co-workers is applied. The single cylinder experiments with direct water injection outline the decreasing carbon monoxide emissions with increasing water content, while the nitrogen oxide emissions indicate only a minor decrease. The simulation results show that the engine can be operated at lambda = 1 at full load using water-fuel ratios of up to 60% or cooled low-pressure exhaust gas recirculation rates of up to 30%. Both technologies enable the reduction of the knock probability and the decrease in the catalyst inlet temperature to protect the aftertreatment system components. The strongest exhaust temperature reduction is found with cooled low-pressure exhaust gas recirculation. With stoichiometric air-fuel ratio and water injection, the indicated efficiency is improved to 40% and the carbon monoxide emissions are reduced. The nitrogen oxide concentrations are increased compared to the fuel-rich base operating conditions and the nitrogen oxide emissions decrease with higher water content. With stoichiometric air-fuel ratio and exhaust gas recirculation, the indicated efficiency is improved to 43% and the carbon monoxide emissions are decreased. Increasing the exhaust gas recirculation rate to 30% drops the nitrogen oxide emissions below the concentrations of the fuel-rich base operating conditions.

stochastic reactor model

efficiency

emissions

spark-ignition engine

exhaust gas recirculation

Water injection

Author

Tim Franken

Brandenburg University of Technology

Fabian Mauss

Brandenburg University of Technology

Lars Seidel

LOGE

Maike Sophie Gern

Technische Universität Berlin

Malte Kauf

Technische Universität Berlin

Andrea Matrisciano

Chalmers, Mechanics and Maritime Sciences (M2), Combustion and Propulsion Systems

Andre Casal Kulzer

Porsche AG

International Journal of Engine Research

1468-0874 (ISSN) 2041-3149 (eISSN)

Vol. 21 10 1857-1877

Subject Categories

Energy Engineering

Chemical Process Engineering

Other Chemical Engineering

DOI

10.1177/1468087420933124

More information

Latest update

10/21/2020