In-Situ Emissions Performance of EPA2010-Compliant On-Highway Heavy-Duty Diesel Engines

Smith, J. M.; Greuel, Justin; Ratkos, Brian; Schauer, Ethan

doi:10.4271/2013-01-2430

Cited by 3 publications

(3 citation statements)

References 8 publications

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“…As this kind of driving can have much stop-and-go traffic, and the idling exhaust is cool and convectively extracts heats from a catalyst system, Gabrielsson [74] showed that an engine stop-start system can be as effective as thermal management methods for maintaining exhaust temperatures. The US EPA identified idling NOx emissions as an issue they wish to investigate, as they measured 6-16% of the NOx from Class 8 trucks came from idling under "normal" driving condition using four trucks [75]. Two trucks measured 27 and 40% of the total NOx from idling.…”

Section: Hydrocarbon Poisoning Of Scr Catalysts Was Summarized Lastmentioning

confidence: 99%

Vehicular Emissions in Review

Johnson¹

2014

SAE Int. J. Engines

139

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The review paper summarizes major developments in vehicular emissions regulations and technologies in 2013. First, the paper covers the key regulatory developments in the field, including proposed light-duty (LD) criteria pollutant tightening in the US; and in Europe, the continuing developments towards real-world driving emissions (RDE) standards. Significant shifts are occurring in China and India in addressing their severe air quality problems. The paper then gives a brief, high-level overview of key developments in fuels. Projections are that we are in the early stages of oil supply stability, which could stabilize fuel prices. LD and HD (heavy-duty) engine technology continues showing marked improvements in engine efficiency. Key developments are summarized for gasoline and diesel engines to meet both the emerging NOx and GHG regulations. HD engines are or will soon be demonstrating 50% brake thermal efficiency using common approaches. NOx control technologies are then summarized, including SCR (selective catalytic reduction) systems and SCR filter developments. Emphasis is on low-temperature deNOx and integration of components and control. Diesel PM (particulate matter) reduction technologies are evolving around the behavior of ash deposits and SCR integration. Filters for direct injection gasoline applications are developing very rapidly, and in some cases the back pressure, light-off characteristics, and emissions reductions are very similar to standard three way catalysts (TWCs). Oxidation catalysts mainly involve developments towards stubborn problems, like low-temperature performance with exhaust with high hydrocarbon and CO, and methane oxidation. Finally, the paper discusses some key developments in gasoline gaseous emission control, focusing on matching engine calibration with emissions system characteristics; and on lean burn gasoline emissions control.

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Section: Hydrocarbon Poisoning Of Scr Catalysts Was Summarized Lastmentioning

confidence: 99%

Vehicular Emissions in Review

Johnson¹

2014

SAE Int. J. Engines

139

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“…Previous studies showed that the current NTE definition is not capable of capturing significant data from transient operation commonly seen in low-load operation where engine frequently drops out of the NTE control area and 30 seconds duration time for an NTE event is found to be too long [15]- [17]. Figure 2 illustrates the total time spent in NTE zone and Routes PA1 and…”

Section: Nte In-use Emissions Regulatory Protocolmentioning

confidence: 99%

“…Accurate flow rate measurement is necessary when mass emissions and fuel consumption rates are need to be measured during on-road vehicle emissions testing [22]. PEMS are widely used for on-road HD vehicle testing [17], [23]. PEMS measure the concentration of the pollutants in the exhaust and multiply the measured exhaust flow rate with the concentration of the pollutants to get mass emission rates [24].…”

Section: Exhaust Flow Measurement and Estimationmentioning

confidence: 99%

Development of an Emissions Monitoring Methodology Using On-Board NOx Sensors and Revision to Current In-Use Emissions Regulatory Protocols

Demirgök¹

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Measurement of in-use emissions from heavy-duty (HD) vehicles under real-world operation has been widely performed by using portable emissions measurement system (PEMS). PEMS serve as an accurate and lightweight emissions measurement system to evaluate in-use emissions from HD vehicles. However, emissions measurement using PEMS instrumentation can be time consuming and labor intensive. Advantage of utilizing already existing on-board sensors such that they can potentially provide an alternative measurement methodology to the PEMS. A successful implementation of an on-board NOx sensor-based methodology for assessing in-use NOx emissions will allow for a cost-effective and simplified approach to monitor real-world, NOx emission rates. The technology of on-board NOx sensors is in its initial stages to be used to monitor in-use NOx emissions and the ability of the sensor to measure NOx concentration during selective catalytic reduction (SCR) activity period is of concern. Furthermore, the on-board NOx sensors are also subject to various cross-sensitivity and durability concerns. The primary objective of this dissertation is to compare the on-board NOx sensor response and accuracy against laboratory grade instrumentation that include PEMS using Non-Dispersive Ultra-Violent (NDUV) and Fourier transform infrared spectroscopy (FTIR) measurement to assess the measurement thresholds of on-board NOx sensors. The study compares the cross-sensitivity of the NOx sensors to ammonia (NH3) concentration in the exhaust. NH3 slip from SCR is believed to interfere with NOx measurements using Zirconium oxide sensors and this study will discuss NH3-NOx cross sensitivity on on-board NOx sensors during real-world HD vehicle activity. Results from this study will compare on-board NOx sensor measurement capabilities and they will be assessed at different power levels related to different SCR conversion efficiency and different NOx concentration levels related to measurements obtained from a laboratory grade emissions

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