GDI Engine Exhaust Aftertreatment System Analysis and Oxygen Sensor Based Identification, Modeling and Control of Lean NOx Trap

2003 ◽  
Author(s):  
Zhengmao Ye
Keyword(s):  
Fuel Economy ◽  
Oxygen Storage ◽  
Chemical Thermodynamics ◽  
Lean Nox Trap ◽  
Exhaust Gas ◽  
Nox Trap ◽  
Exhaust Gas Aftertreatment ◽  
Lean Nox ◽  
Gdi Engine ◽  
Aftertreatment Systems

This paper presents a thorough analysis of the exhaust gas aftertreatment systems of Gasoline Direct Injection (GDI) engines. The mechanism of the exhaust gas aftertreatment systems is investigated using chemical thermodynamics. The physical models of three-way-catalyst (TWC) and lean NOx trap (LNT) are presented. The objective is to propose an alternative approach for the identification of A/F ratio and oxygen concentration in the exhaust systems to substitute the costly oxygen sensors. A simple control scheme is included within the model identification and prediction results are compared with the testing data from the universal exhaust gas oxygen (UEGO) sensor and from the heated exhaust gas oxygen (HEGO) sensor. The oxygen storage effect has an essential impact on the LNT storage and purge operations, which will also affect the overall fuel economy of GDI engine systems. Its influence on the fuel economy has been estimated by numerical simulations, which is correspondent to the extra percentage of fuel consumption.

scholarly journals High-pressure versus low-pressure exhaust gas recirculation in a Euro 6 diesel engine with lean-NOx trap: Effectiveness to reduce NOx emissions

2018 ◽  
Vol 20 (1) ◽  
pp. 155-163 ◽  
Author(s):  
Magín Lapuerta ◽  
Ángel Ramos ◽  
David Fernández-Rodríguez ◽  
Inmaculada González-García
Keyword(s):  
High Pressure ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Lean Nox Trap ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Nox Trap ◽  
Aftertreatment System ◽  
Lean Nox ◽  
Gas Recirculation

Exhaust gas recirculation can be achieved by means of two different routes: the high-pressure route (high-pressure exhaust gas recirculation), where exhaust gas is conducted from upstream of the turbine to downstream of the compressor, and the low-pressure one (low-pressure exhaust gas recirculation), where exhaust gas is recirculated from downstream of the turbine and of the aftertreatment system to upstream of the compressor. In this study, the effectiveness of both exhaust gas recirculation systems on the improvement of the NOx-particulate matter emission trade-off has been compared on a Euro 6 turbocharged diesel engine equipped with a diesel oxidation catalyst, a lean-NOx trap, and a diesel particulate filter. Emissions were measured both upstream and downstream of the aftertreatment system, at different combinations of engine speed and torque (corresponding to different vehicle speeds), at transient and steady conditions, and at different coolant temperatures as switch points to change from high-pressure exhaust gas recirculation to low-pressure exhaust gas recirculation. It was shown that low-pressure exhaust gas recirculation was more efficient than high-pressure exhaust gas recirculation to reduce NOx emissions, mainly due to the higher recirculation potential and the lower temperature of the recirculated gas. However, such a differential benefit decreased as the coolant temperature decreased, which suggests the use of high-pressure exhaust gas recirculation during the engine warm-up. It was also shown that the lean-NOx trap storage efficiency decreased more rapidly at high engine load than at medium load and that such reduction in efficiency was much faster when high-pressure exhaust gas recirculation was used than when low-pressure exhaust gas recirculation was used.

Prospects for the use of dry carbamide in diesel exhaust gas aftertreatment systems

2019 ◽  
pp. 3-14
Author(s):  
V.N. Kaminskij ◽  
◽  
G.G. Nadarejshvili ◽  
V.I. Panchishnyj ◽  
R.M. Zagredinov ◽  
...  
Keyword(s):  
Diesel Exhaust ◽  
Exhaust Gas ◽  
Exhaust Gas Aftertreatment ◽  
Aftertreatment Systems

Fuel economy, NOx emissions and lean NOx trap efficiency: Lessons from current driving cycles

2021 ◽  
pp. 146808742110050
Author(s):  
José Rodríguez-Fernández ◽  
Juan José Hernández ◽  
Ángel Ramos ◽  
Alejandro Calle-Asensio
Keyword(s):  
Fuel Economy ◽  
Thermal Efficiency ◽  
Transport Sector ◽  
Lean Nox Trap ◽  
Ambient Temperatures ◽  
Exhaust Temperature ◽  
Driving Cycles ◽  
Vehicle Velocity ◽  
Two Factors ◽  
Lean Nox

Transport sector is within a profound changing period, but diesel engines are still called to play a significant role in future supported on their solid share in many regions and superior thermal efficiency compared to spark-ignited engines. This work identifies the parameters that most affect fuel consumption and NOx emissions on a diesel passenger car equipped with a lean NOx trap under different driving cycles and ambient temperatures. High average vehicle velocity was beneficial to reduce the fuel consumed per kilometer. The driving dynamics was of little importance, easily counteracted by a higher thermal efficiency, higher engine temperature (because of a longer trip) or/and an efficient gear shifting strategy. Moreover, at low ambient temperature the latter two factors doubled their weight on fuel economy. Regarding tailpipe NOx, keeping high aftertreatment performance was crucial. For this, low engine-out NOx emissions were four times more important than exhaust temperature or flow rate.

Characteristics of Pt–K/MgAl2O4 lean NOx trap catalysts

2012 ◽  
Vol 184 (1) ◽  
pp. 2-7 ◽  
Author(s):  
Do Heui Kim ◽  
K. Mudiyanselage ◽  
J. Szányi ◽  
H. Zhu ◽  
J.H. Kwak ◽  
...  
Keyword(s):  
Lean Nox Trap ◽  
Nox Trap ◽  
Lean Nox

Reaction pathway of the reduction by CO under dry conditions of NOx species stored onto PtBa/Al2O3 Lean NOx Trap catalysts

2010 ◽  
Vol 274 (2) ◽  
pp. 163-175 ◽  
Author(s):  
Pio Forzatti ◽  
Luca Lietti ◽  
Isabella Nova ◽  
Sara Morandi ◽  
Federica Prinetto ◽  
...  
Keyword(s):  
Reaction Pathway ◽  
Lean Nox Trap ◽  
Nox Trap ◽  
Lean Nox ◽  
Dry Conditions

Modelling of a Lean NOx-Trap system with NO/NO2 differentiation and sulfur poisoning

2010 ◽  
Vol 3 (2) ◽  
pp. 414-424 ◽  
Author(s):  
Alexis Manigrasso ◽  
PIerre Darcy ◽  
Patrick Da Costa
Keyword(s):  
Sulfur Poisoning ◽  
Lean Nox Trap ◽  
Nox Trap ◽  
Trap System ◽  
Lean Nox
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