Model Predictive Air-Fuel Ratio Control for an Integrated Gasoline Engine and Three-Way Catalytic Converter System

2018 ◽  
Author(s):  
Kuo Yang ◽  
Pingen Chen
Keyword(s):  
Gasoline Engine ◽  
Combustion Engine ◽  
Catalytic Converter ◽  
Fuel Efficiency ◽  
Integrated System ◽  
Oxygen Storage ◽  
System Control ◽  
Fuel Ratio ◽  
Conversion Efficiencies ◽  
Control Methodology

With increasingly demanding regulations on engine emission and fuel efficiency, the optimization of the internal combustion engine and the after-treatment integrated system has become a critical research focus. To address such an issue, this paper aims to achieve a better trade-off between the fuel consumption of a spark-ignited (SI) engine and emission conversion efficiencies of a Three-Way Catalytic converter (TWC) system. A Model Predictive Control (MPC)-based integrated engine and TWC control methodology is presented, which is able to optimize Air/Fuel Ratio (AFR) to maintain oxygen storage of TWC at a desired level and thus meet the tailpipe NOx, CO and HC emission requirements. The effectiveness of the presented control methodology is validated in simulation. Compared with the existing dithering-based AFR control, the proposed MPC-based AFR control can improve CO emission conversion efficiencies by 8.42% and 4.85% in simplified US06 and UDDS driving cycles, respectively. At the same time, Nitrogen Oxides (NOx) conversion efficiency maintains above the required limit of 95% and the fuel efficiency remains at the same level as the existing control methodology in production as well. Such an integrated engine-aftertreatment system control can be instrumental in improving engine efficiency and emission reduction performance.

Model-Based Predictive Control and Dithering Control for an Integrated Gasoline Engine and Three-Way Catalytic Converter System

2021 ◽  
Author(s):  
Kuo Yang ◽  
Pingen Chen
Keyword(s):  
Predictive Control ◽  
Gasoline Engine ◽  
Catalytic Converter ◽  
Fuel Efficiency ◽  
Operating Conditions ◽  
Oxygen Storage ◽  
Model Based ◽  
Emission Regulation ◽  
Fuel Efficiency Improvement ◽  
Conversion Efficiencies

Abstract Controls of integrated gasoline engine and after-treatment systems are critical for fuel efficiency improvement and emission regulation. This paper aims to develop novel model-based Three-Way Catalytic converter (TWC) controls to reduce the fuel consumption and tailpipe emissions for a gasoline engine. A model-based dither control and a nonlinear model predictive control (MPC)-based control, are presented, respectively. The proposed TWC dither control utilizes a systematically designed dither cycle configuration (including dithering amplitude, offset, and frequency) based on a control-oriented model, with the capability to adapt the dither cycle configuration to various engine operating conditions. The MPC control can optimize engine air-fuel ratio (AFR) to maintain the oxygen storage of TWC at a desired level and thus meet the tailpipe NOx, CO and HC emission requirements. The efficacies of both model-based TWC controls are validated in simulation with MPC control improving CO emission conversion efficiencies by 8.42% and 4.85% in simplified US06 and UDDS driving cycles, when compared to a baseline dithering-based AFR control. Meanwhile, NOx emission conversion efficiency is maintained above the required limit of 95%, while the fuel efficiency remains at the same level as the baseline control methodology.

Methodology to Evaluate the Fuel Economy of a Multimode Combustion Engine With Three-Way Catalytic Converter

2014 ◽  
Author(s):  
Sandro P. Nüesch ◽  
Anna G. Stefanopoulou ◽  
Li Jiang ◽  
Jeffrey Sterniak
Keyword(s):  
Fuel Economy ◽  
Combustion Engine ◽  
Catalytic Converter ◽  
Oxygen Storage ◽  
Nox Emissions ◽  
Combustion Mode ◽  
Mode Switch ◽  
Drive Cycle ◽  
Finite State ◽  
The Impact

Highly diluted, low temperature homogeneous charge compression ignition (HCCI) combustion leads to ultra-low levels of engine-out NOx emissions. A standard drive cycle, however, would require switches between HCCI and spark-ignited (SI) combustion modes. In this paper a methodology is introduced, investigating the fuel economy of such a multimode combustion concept in combination with a three-way catalytic converter (TWC). The TWC needs to exhibit unoccupied oxygen storage sites in order to show acceptable performance. But the lean exhaust gas during HCCI operation fills the oxygen storage and leads to a drop in NOx conversion efficiency. Eventually the levels of NOx become unacceptable and a mode switch to a fuel rich combustion mode is necessary in order to deplete the oxygen storage. The resulting lean-rich cycling leads to a penalty in fuel economy. In order to evaluate the impact of those penalties on fuel economy, a finite state model for combustion mode switches is combined with a longitudinal vehicle model and a phenomenological TWC model, focused on oxygen storage. The aftertreatment model is calibrated using combustion mode switch experiments from lean HCCI to rich spark-assisted HCCI and back. Fuel and emissions maps acquired in steady state experiments are used. Two depletion strategies are compared in terms of their influence on drive cycle fuel economy and NOx emissions.

Layer-by-layer mixing in engines with direct gasoline injection

2020 ◽  
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engine ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Layer By Layer ◽  
Engine Fuel ◽  
Working Process ◽  
Layered Charge

Features of the design and operation of engines with direct injection of gasoline into the cylinders and layer-by-layer mixing are considered. Opportunities of improving the engine fuel efficiency and exhaust gases toxicity characteristics with this organization of the working process are shown. Problems arising when organizing such a working process of a gasoline engine are noted. Keywords internal combustion engine; diesel engine; gasoline engine; direct injection; layer-by-layer mixing; layered charge; lean mixture

scholarly journals Fuel Economy of a Multimode Combustion Engine With Three-Way Catalytic Converter

2014 ◽  
Vol 137 (5) ◽  
Author(s):  
Sandro P. Nüesch ◽  
Anna G. Stefanopoulou ◽  
Li Jiang ◽  
Jeff Sterniak
Keyword(s):  
Fuel Economy ◽  
Combustion Engine ◽  
Catalytic Converter ◽  
Combustion Efficiency ◽  
Oxygen Storage ◽  
Nox Emissions ◽  
Combustion Mode ◽  
Mode Switch ◽  
Drive Cycle ◽  
The Impact

Highly diluted, low temperature homogeneous charge compression ignition (HCCI) combustion leads to ultralow levels of engine-out NOx emissions. A standard drive cycle, however, would require switches between HCCI and spark-ignited (SI) combustion modes. In this paper we quantify the efficiency benefits of such a multimode combustion engine, when emission constraints are to be met with a three-way catalytic converter (TWC). The TWC needs unoccupied oxygen storage sites in order to achieve acceptable performance. The lean exhaust gas during HCCI operation, however, fills the oxygen storage and leads to a drop in NOx conversion efficiency. If levels of tailpipe NOx become unacceptable, a mode switch to a fuel rich combustion mode is necessary in order to deplete the oxygen storage and restore TWC efficiency. The resulting lean-rich cycling leads to a penalty in fuel economy. Another form of penalty originates from the lower combustion efficiency during a combustion mode switch itself. In order to evaluate the impact on fuel economy of those penalties, a finite state model for combustion mode switches is combined with a longitudinal vehicle model and a phenomenological TWC model, focused on oxygen storage. The aftertreatment model is calibrated using combustion mode switch experiments from lean HCCI to rich spark-assisted HCCI (SA-HCCI) and back. Fuel and emission maps acquired in steady-state experiments are used. Different depletion strategies are compared in terms of their influence on drive cycle fuel economy and NOx emissions. It is shown that even an aggressive lean-rich cycling strategy will marginally satisfy the cumulated tailpipe NOx emission standards under warmed-up conditions. More notably, the cycling leads to substantial fuel penalties that negate most of HCCI's efficiency benefits.

A case study on particulate emissions from a gasoline plug-in hybrid electric vehicle during engine warm-up, taking into account start–stop operation

2020 ◽  
Vol 234 (13) ◽  
pp. 2907-2922
Author(s):  
Martin Lenz ◽  
Moritz Cremer ◽  
Daniel Guse ◽  
Henning Röhrich ◽  
Stefan Pischinger
Keyword(s):  
Electric Vehicle ◽  
Hybrid Electric Vehicle ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Catalytic Converter ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Warm Up ◽  
Hybrid Electric

Concerning the discussions about emissions caused by individual mobility, it is foreseeable that future vehicle concepts will increasingly be based on hybrid powertrains. These systems lead to more complex operating scenarios, which have a significant influence on the resulting emissions of the engine. This work shows a case study and the results in the operation and emission behavior of a plug-in hybrid electric vehicle with a direct injection gasoline engine when operated in an internationally recognized driving cycle. The vehicle’s exhaust aftertreatment system consists of a three-way catalytic converter; a particulate filter is not installed. The emissions are analyzed with a focus on particulate number emissions (from soot), especially during the warm-up phase and the frequent start–stop events (in total, there are 12 internal combustion engine operating phases), which are typical for hybrid vehicles. The results show that approximately 50% of the emitted particulates have a smaller size, 23 nm (a very high number of particulates with a mean size of 10 to 15 nm are present), which are currently not regulated, but are expected to have a high risk of adverse health effects.

Nanostructured Cerium Oxide “Ecocatalysts”

MRS Bulletin ◽  
2001 ◽  
Vol 26 (11) ◽  
pp. 885-889 ◽  
Author(s):  
Maria Flytzani-Stephanopoulos
Keyword(s):  
Cerium Oxide ◽  
Catalytic Converter ◽  
Oxygen Storage Capacity ◽  
Industrial Applications ◽  
Oxygen Storage ◽  
Metal Catalyst ◽  
Fuel Ratio ◽  
Zirconium Oxides ◽  
Recent Compilation ◽  
Three Way Catalyst

Catalysts based on cerium oxide are now used as effective oxidation systems in numerous environmental applications. Cerium oxide was introduced into the catalysis field relatively recently, in 1976, and not as a catalyst initially. Rather, it was chosen as the key oxygen-storage component of the three-way catalyst (TWC) used in automotive exhausts. Accordingly, ceria is used to extend the air/fuel ratio window in the exhaust gas, releasing or accepting oxygen, respectively, under fuel-rich or fuellean conditions, so that the noble metal catalyst operates at the desirable stoichiometric air/fuel ratio, at which it effectively converts all three gaseous pollutants—CO, hydrocarbons, and NO—to innocuous products. A solid solution of cerium and zirconium oxides is used in today's catalytic converters because of its higher oxygen-storage capacity (OSC) compared with pure ceria. In the years that followed the introduction of ceria into the catalytic converter, many additional merits of cerium oxide were realized, first as an active catalytic component of the TWC and subsequently as a catalyst and sorbent in various industrial applications. A review article by Trovarelli on ceria-based catalysts is a good recent compilation.

scholarly journals Small Cogeneration Unit with Heat and Electricity Storage

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2102
Author(s):  
Josef Stetina ◽  
Michael Bohm ◽  
Michal Brezina
Keyword(s):  
Internal Combustion Engine ◽  
Cooling System ◽  
Combustion Engine ◽  
Catalytic Converter ◽  
Storage System ◽  
Internal Combustion ◽  
Energy Storage System ◽  
Balance Model ◽  
Exhaust Pipe ◽  
Water Storage Tank

A micro cogeneration unit based on a three-cylinder internal combustion engine, Skoda MPI 1.0 L compressed natural gas (CNG), with an output of 25 kW at 3000 RPM is proposed in this paper. It is a relatively simple engine, which is already adopted by the manufacturer to operate on CNG. The engine life and design correspond to the original purpose of use in the vehicle. A detailed dynamic model was created in the GT-SUITE environment and implemented into an energy balance model that includes its internal combustion engine, heat exchangers, generator, battery storage, and water storage tank. The 1D internal combustion engine model provides us with information on engine start-up time, actual effective power, friction power, and the amount of heat going to the cooling system and exhaust pipe. The catalytic converter was removed from the exhaust pipe, and the engine was always operating at full load; thus, engine power control is not considered. An energy storage system for an island operation of the entire power unit for a large, detached house was designed to withstand accumulated energy for a few days in the case of a breakout. To reach a low initial system cost, the possible implementation of worn-out battery packs toward emission reduction in terms of the second life of the battery is proposed. The energy and emission balance are carried out, and the service life of the engine is also discussed.

Sign in / Sign up

Export Citation Format

Share Document