scholarly journals Model Predictive Control of a Lean-Burn Gasoline Engine Coupled With a Passive Selective Catalytic Reduction System

2017 ◽  
Author(s):  
Qinghua Lin ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko
Keyword(s):  
Predictive Control ◽  
Gasoline Engine ◽  
Catalytic Reduction ◽  
Efficiency Gain ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Engine Efficiency ◽  
Emission Standards ◽  
Tier 3 ◽  
Passive Scr

Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) Corporate Average Fuel Economy standard by 2025. Nevertheless, NOx emissions control for lean-burn gasoline for meeting the stringent EPA Tier 3 emission standards has been one of the main challenges towards the commercialization of highly-efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines but may cause significant fuel penalty due to ammonia generation via rich engine combustion. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the fuel penalty associated with passive SCR operation while satisfying stringent NOx and NH3 emissions requirements. Simulation results demonstrate that the MPC-based control can reduce the fuel penalty by 47.7% in a simulated US06 cycle and 32.0% in a simulated UDDS cycle, compared to the baseline control, while achieving over 96% deNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC control can potentially enable high engine efficiency gain for highly-efficient lean-burn gasoline engine while meeting the stringent EPA Tier 3 emission standards.

scholarly journals Experimental Study and Model Predictive Control of a Lean-Burn Gasoline Engine Coupled With a Passive Selective Catalytic Reduction System

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Qinghua Lin ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko
Keyword(s):  
Predictive Control ◽  
Environmental Protection Agency ◽  
Gasoline Engine ◽  
Catalytic Reduction ◽  
Protection Agency ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Emission Standards ◽  
Tier 3 ◽  
Passive Scr

Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) corporate average fuel economy standard by 2025. Nevertheless, nitrogen oxides (NOx) emissions control for lean-burn gasoline for meeting the stringent Environmental Protection Agency tier 3 emission standards has been one of the main challenges toward the commercialization of highly efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst (TWC) and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines at low cost. However, passive SCR operation may cause significant fuel penalty since rich engine combustion is required for ammonia generation. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the total equivalent fuel penalty associated with passive SCR operation while satisfying stringent NOx and ammonia (NH3) emissions requirements. Simulation results demonstrate that the MPC approach can reduce the fuel penalty by 43.9% in a simulated US06 cycle and 28.0% in a simulated urban dynamometer driving schedule (UDDS) cycle, respectively, compared to the baseline control, while achieving over 97% DeNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC controller can potentially enable highly efficient lean-burn gasoline engines while meeting the stringent Environmental Protection Agency tier 3 emission standards.

Optimization of Mode Switching Timing Control for a Lean-Burn Gasoline Engine With a Prototype Passive SCR System

2018 ◽  
Author(s):  
Dakota Strange ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko ◽  
James E. Parks
Keyword(s):  
Gasoline Engine ◽  
Nox Reduction ◽  
Cost Effective ◽  
Nox Storage ◽  
Mode Switching ◽  
Timing Control ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Effective Manner ◽  
Passive Scr

Passive selective catalytic reduction (SCR) has emerged as a promising NOx reduction technology for highly-efficient lean-burn gasoline engines to meet stringent NOx emission regulation in a cost-effective manner. In this study, a prototype passive SCR which includes an upstream three-way catalyst (TWC) with added NOx storage component, and a downstream urealess SCR catalyst, was investigated. Engine experiments were conducted to investigate and quantify the dynamic NOx storage/release behaviors as well as dynamic NH3 generation behavior on the new TWC with added NOx storage component. Then, the lean/rich mode-switching timing control was optimized to minimize the fuel penalty associated with passive SCR operation. Simulation results show that, compared to the baseline mode-switching timing control, the optimized control can reduce the passive SCR-related fuel penalty by 6.7%. Such an optimized mode-switching timing control strategy is rather instrumental in realizing significant fuel efficiency benefits for lean-burn gasoline engines coupled with cost-effective passive SCR systems.

Configuration and Control Design for a Passive SCR System With NOx Storage Capability

2018 ◽  
Author(s):  
Qinghua Lin ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko ◽  
James E. Parks
Keyword(s):  
Catalytic Reduction ◽  
Nox Reduction ◽  
Cost Effective ◽  
Nox Storage ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Generation Cost ◽  
Lean Nox ◽  
Scr System ◽  
Passive Scr

Passive selective catalytic reduction (SCR) systems have been considered as a promising technology for reducing NOx emissions for highly-efficient lean burn gasoline engines. Since passive SCR requires intermittent rich operation for self-generating ammonia (NH3) for NOx reduction in the lean phase, the fuel penalty associated with NH3 generation may be significant. To address this issue, a new prototype passive SCR system with NOx storage capability was recently investigated. The three-way catalyst (TWC) with added NOx storage capability is able to enhance NH3 production rate by utilizing pre-stored NOx and thus reduce the fuel cost related to NH3 production. The main purpose of this study is to reduce the ammonia generation cost by: 1) proposing a new passive SCR system architecture that includes two TWC stages; and 2) developing and optimizing a novel non-uniform cylinder-to-cylinder combustion (NUCCC) control. Optimization results based on the experimental data from a physical engine platform, demonstrate that the new passive SCR system (with NOx storage components on TWCs), in conjunction with optimized NUCCC control, is capable of reducing ammonia specific fuel consumption (ASFC) by 30.2%, when compared to a uniform cylinder-to-cylinder combustion (UCCC)-controlled baseline passive SCR system. Such a novel NUCCC control and innovative passive SCR configuration, will be very instrumental in creating cost-effective lean NOx emission control solutions for lean-burn engines in the future.

Tumble Flow Measurements Using Three Different Methods and Its Effects on Fuel Economy and Emissions

2006 ◽  
Author(s):  
Myoungjin Kim ◽  
Sihun Lee ◽  
Wootae Kim
Keyword(s):  
Fuel Economy ◽  
High Performance ◽  
Gasoline Engine ◽  
Exhaust Emissions ◽  
Combustion Stability ◽  
Lean Burn ◽  
Flow Measurements ◽  
Part Load ◽  
Gasoline Engines ◽  
Dynamometer Test

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.

scholarly journals EFEK LOKASI INJEKTOR TERHADAP INDEKS PENCAMPURAN AMMONIA UNTUK SCR DENGAN MIXER DINAMIK

ROTASI ◽  
2014 ◽  
Vol 16 (4) ◽  
pp. 48
Author(s):  
Syaiful Syaiful ◽  
Iseu Andriani
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
High Efficiency ◽  
Gasoline Engine ◽  
Catalytic Reduction ◽  
Threshold Level ◽  
Nox Emissions ◽  
Mixing Index ◽  
Engine Exhaust ◽  
Gasoline Engines

Diesel engines many are used as transportation mode in the land and sea compared with gasoline engines due to their high efficiency and durability. However, diesel engine releases much more NOx and soot emissions than that of gasoline engine. NOx is formed from a reaction of Nitrogen and Oxygen at high temperature. If these emissions are breathed into human body resulting respiratory disorders such as emphysema and bronchitis as well as lungs tissue damage. Therefore, NOx emissions controll is required to reduce them reaching under a threshold level. An effective method for controlling NOx emissions produced by the diesel engines is by injecting ammonia obtained from urea into selective catalytic reduction (SCR method) system. Ammonia by means of catalyst reacts with NOx forming Nitrogen (N2) and Water (H2O). Therefore, a chance of each ammonia particle to react with each NOx particle is required to consider. A reaction quality between ammmonia and NOx particles can be increased by improving a mixing index. One of the methods to increase the mixing index is by using a dynamic mixer.There are several factors which influence the increase of mixing index. One of these factors is a location of ammonia injector. Since this work is focused on investigating the effect of ammonia injector location on the mixing index of ammonia to diesel engine exhaust gases which content of NOx emissions

Passive TWC+SCR Systems for Satisfying Tier 2, Bin 2 Emission Standards on Lean-Burn Gasoline Engines

2015 ◽  
Vol 8 (2) ◽  
pp. 460-473 ◽  
Author(s):  
Joseph R. Theis ◽  
Jeong Kim ◽  
Giovanni Cavataio
Keyword(s):  
Tier 2 ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Emission Standards

Evaluation of In-Situ Synthesized Monolithic Metal-MFI/Cordierite Catalysts to Remove NOx From Lean Exhaust

2005 ◽  
Author(s):  
Tianyou Wang ◽  
Shuliang Liu ◽  
Hongjun Xu ◽  
Xing Li ◽  
Maolin Fu ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Gasoline Engine ◽  
Catalytic Reduction ◽  
Space Velocity ◽  
Test Results ◽  
Lean Burn ◽  
Exhaust Temperature ◽  
Nox Conversion ◽  
Nox Conversion Efficiency

In this study, ZSM-5 zeolites were successfully in situ synthesized on the surface of honeycomb cordierite substrate and certified by XRD and SEM techniques. Strong interaction between zeolite and substrate has been found during in-situ synthesis, and hydrothermal stabilities of the zeolites was improved by entailing. The in-situ synthesized monolithic ZSM-5/cordierite showed superior thermal and hydrothermal stabilities. Cu-ZSM-5/cordierite was prepared by ion-exchange and impregnation methods were studied as catalysts for selective catalytic reduction (SCR) of nitrogen oxides (NOx) in a lean-burn gasoline engine. Engine test results show that NOx emission was decreased by reductants of HC and CO in the exhaust gas without any other extra reducing agents. It also exhibited high activities. Using Cu-ZSM-5/cordierite, the maximum NOx conversion efficiency to N2 reached to 64% at the exhaust temperature of 400 °C and the gas hourly space velocity (GHTV) of 25 000/h. Meanwhile, the HC conversion efficiency was about 60%, while CO was little converted. Cu-ZSM-5/cordierite also showed good duration and anti-poison properties. Furthermore, the activated temperature of the Cu-ZSM-5/cordierite was decreased and the NOx conversion was increased via addition of iridium as a modifier.

scholarly journals Research on Metal Doped Zeolite as Catalyst to Reduce NOX Emission from Lean Burn Gasoline Engines

2019 ◽  
Vol 8 (5S3) ◽  
pp. 201-206 ◽  
Keyword(s):  
Gasoline Engine ◽  
Fuel Injection ◽  
Catalytic Converter ◽  
Nox Emission ◽  
Gasoline Direct Injection ◽  
Oxidation Catalyst ◽  
Gas Temperature ◽  
Lean Burn ◽  
Exchange Method ◽  
Gasoline Engines

Lean burn gasoline direct injection (GDI) engines are the most preferred gasoline engines because of their low fuel consumption and high thermal efficiency. However, these engines produce exhaust gases that are particularly rich in oxygen and therefore the present three-way catalytic converter (TWC) is not suitable for converting the generated NOX emission into Nitrogen gases. In this present work, a new method of reducing Nitrogen Oxides emission in a gasoline engine is attempted by using an ordinary oxidation catalyst together with a deNOX(zeolite-based) catalyst. In this work, Na-form of ZSM-5 zeolite was used as a catalyst and cupric chloride (CuCl2) and ferric chloride (FeCl3) where used as transition metals. Cu-ZSM5 and Fe-ZSM5 catalyst were prepared separately in our laboratory. Na+ ion exchange method is used to prepare the catalyst. After that Cu-ZSM% and Fe- ZSM5 catalyst were washcoated separately onto the blank monoliths. Oxidation monoliths ( for oxidation of CO and HC into CO2 and H2O) were purchased directly from market. One oxidation monolith and one zeolite coated monolith were placed in a stainless steel container and canned with inlet and outlet cones ( forming catalytic convertor ). Experiments were conducted on a 2 cylinder Multi Point Port Fuel Injection engine along with a dynamometer. Exhaust emissions such as NOX, CO, HC, O2, CO2 were measured with AVL Di-gas-444 Analyzer. Exhaust gas temperature is measured with the use of a thermocouple. Firstly load tests (4, 7, 10, 13, and 16KW) were conducted on the engine without catalytic convertor was fixed close to the outlet pipe and the test were conducted again with same loading condition as mentioned above. Then by the same above procedure is followed to conduct test with Cu-ZSM5 and Fe-ZSM5 catalytic convertors. From the results it is observed that both Cu and Fe zeolite catalyst minimize emissions than the commercial catalytic converter.

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