Investigation of Post Oxidation and Its Dependency on Engine Combustion and Exhaust Manifold Design

Koehlen, Christoph; Holder, Eberhard; Vent, Guido

doi:10.4271/2002-01-0744

Cited by 20 publications

(10 citation statements)

References 8 publications

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“…Strategies with additional hardware components that enable a fast heat-up process, such as secondary air pumps [5][6][7] or electric heaters [8,9]. 2.…”

Section: Introductionmentioning

confidence: 99%

Optimal Cold-Start Control of a Gasoline Engine

2017

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This article analyzes the influence of the ignition retardation on the fuel consumption, the cumulative tailpipe hydrocarbon emissions, and the temperature inside the three-way catalytic converter in a gasoline direct injection engine operated under idling conditions. A dedicated cylinder-individual, model-based, multivariable controller was used in experiments in order to isolate the effect of the ignition retardation on the hydrocarbon emissions as much as possible. An optimal control problem for a gasoline engine at a cold-start is formulated, which is used to interpret the experimental data obtained. The corresponding goal is to minimize the fuel consumption during an initial idling phase of a fixed duration while guaranteeing that the three-way catalytic converter reaches a sufficiently high final temperature and at the same time making sure that the cumulative hydrocarbon emissions stay below a given limit. The experimental data indicates that the engine should be operated with maximum ignition retardation in order to reach any temperature inside the three-way catalytic converter as quickly as possible concurrently with minimum tailpipe emissions and with the minimum possible fuel consumption.

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“…Strategies with additional hardware components that enable a fast heat-up process, such as secondary air pumps [5][6][7] or electric heaters [8,9]. 2.…”

Section: Introductionmentioning

confidence: 99%

Optimal Cold-Start Control of a Gasoline Engine

2017

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“…Following the engine cold start, the catalytic converter has not yet reached its operating temperature, so most of the hydrocarbon emissions are untreated. A study has suggested that more than 80% of the hydrocarbon emission measured over the entire FTP-75 drive cycle are emitted within the first 20 seconds after the engine has started [1]. The performance of the catalyst can be optimized if the EGT is known.…”

Section: Introductionmentioning

confidence: 99%

Instantaneous Exhaust Temperature Measurements Using Thermocouple Compensation Techniques

Kar¹,

Roberts²,

Stone³

et al. 2004

SAE Technical Paper Series

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This paper discusses a method of measuring the instantaneous exhaust gas temperature by thermocouples. Measuring the exhaust gas temperature is useful for a better understanding of engine processes. Thermocouples do not measure the instantaneous exhaust gas temperature because of their limited dynamic response. A thermocouple compensation technique has been developed to estimate the time constant in situ. This method has been commissioned in a simulation study and a controlled experiment with a reference temperature. The studies have shown that the signal bandwidth has to be restricted, since noise will be amplified in the temperature reconstruction. The technique has been successfully applied to some engine exhaust measurements. A comparison between two independent pairs of thermocouples has shown that temperature variations at frequencies up to 80Hz can be recovered. The medium load results agree with a previous study, which used fast response thermometers with a bandwidth of about 50 Hz. However, the results at low load and two different speeds have highlighted the need to do some 1-D unsteady flow simulations, in order to gain more insight into the exhaust process.

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“…They had seen that as the O 2 content was increasing in the exhaust manifold, the mass flow rate and enthalpy generated was also increasing which in the end contributed to higher pressure and temperature which led to better actuation of post-oxidation reaction. [14][15][16][17][18] Besides scavenging, second factor by the name of VVT also played a key role in the reaction. According to a study, VVT tuning had greatly aided in the post-oxidation reaction and towards turbo-lag reduction as well.…”

Section: Introductionmentioning

confidence: 99%

“…Along with ignition timing, VVT, injection timing, the parameters such as amount of air, temperature, exhaust gases residing time in the exhaust manifold and quality of mixture formation also contributes to a good post-oxidation phenomenon to take place. 15 From the aforementioned factors, the aim of this research study was to improve the quality of mixture formation that can help us to achieve even a better reaction, but pressure pulses, which are a common hindrance in the mixture formation process needs to be taken into consideration as well. A study was conducted in which a new kind of geometry for the exhaust manifold was created and tested experimentally.…”

Section: Introductionmentioning

confidence: 99%

Performance improvement of turbocharged SI engine by post-oxidation enhancement in exhaust gas in-homogeneity

Kumar

Moeeni

Kuboyama

et al. 2020

International Journal of Engine Research

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In this research, the improvement of mixing and pulsation in exhaust manifold with a design and implementation of bypass adapter at exhaust port were deeply investigated. This in-turn can improve the post-oxidation phenomena and hence emissions and engine performance could be enhanced. This research investigation includes 1-D, 3-D simulations and experimental validation on a 4-cylinder turbocharged spark ignition (SI) engine. Firstly, the 1-D and 3-D simulation models were developed and calibrated with the experimental results. Then, the simulations were used for the detailed investigation of mixing and pulsation in exhaust manifold with and without bypass adapter. Thereafter, experimental test for the post-oxidation were conducted with and without consideration of the bypass adapter and results were compared. From the simulation and experimental results, it was proven that by using bypass adapter at the exhaust port, the mixing of exhaust gas species was observed to be significantly improved to some extent. Also, the unbalance between exhaust port and turbocharger upstream gas species were reduced. This also reduced the exhaust gas pulsation. By the improvement of mixing between scavenged O2 and unburned gas species, the post-oxidation reaction was also noted to have improved and consequently the emissions and turbo-speed were found to be better that led to an improved IMEP and thermal efficiency of the engine.

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Investigation of Post Oxidation and Its Dependency on Engine Combustion and Exhaust Manifold Design

Cited by 20 publications

References 8 publications

Optimal Cold-Start Control of a Gasoline Engine

Optimal Cold-Start Control of a Gasoline Engine

Instantaneous Exhaust Temperature Measurements Using Thermocouple Compensation Techniques

Performance improvement of turbocharged SI engine by post-oxidation enhancement in exhaust gas in-homogeneity

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