Analysis of Emission Factors in RDE Tests As Well as in NEDC and WLTC Chassis Dynamometer Tests

Merkisz, Jerzy; Pielecha, Jacek; Bielaczyc, Piotr; Woodburn, Joseph

doi:10.4271/2016-01-0980

Cited by 45 publications

(23 citation statements)

References 16 publications

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“…These results are generally in agreement with those of Weiss et al [14]. Merkisz et al [16] conducted an extensive study, testing 150 different Euro4 and Euro 5 cars on RDE tests and comparing results to corresponding NEDC and WLTC tests. A Semtech DS analyzer was the PEMS used for this study, and the protocol being considered for EU RDE legislation at the time was employed.…”

Section: Introductionsupporting

confidence: 79%

“…This would indicate that these parameters, though useful in defining the type of cycle, are not indicative of the emissions behavior of such cycles. The emissions results tend to agree with those of Merkisz et al [13] regarding the decrease in on-road emission factors compared to those of chassis dynamometer tests, but are in contrast to those of Merkisz et al [16] and May et al [15]. This is particularly interesting given that the average RPA of the current work was found to be greater than in the latter of these two studies.…”

Section: Emission Comparisonscontrasting

confidence: 52%

See 1 more Smart Citation

A Comparison of Tailpipe Gaseous Emissions for RDE and WLTC Using SI Passenger Cars

Thomas¹,

Li²,

Wang³

et al. 2017

SAE Technical Paper Series

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The drive characteristics and gaseous emissions of legislated Real Driving Emissions (RDE) test data from 8 different spark ignition vehicles were compared to data from corresponding Worldwide harmonized Light vehicles Test Cycle (WLTC) tests. The effect of the official RDE exclusion of cold start and idling on the RDE test, and the effect of the use of the moving averaging window (MAW) analysis technique, were simultaneously investigated. Specific attention was paid to differences in drive characteristics of the three different driving modes and the effect this had on the distance-based CO2, CO and NOx emission factors for each. The average velocity of the RDE tests was marginally greater than the WLTC tests, while the average acceleration was smaller. The CO2 emission appeared on average 4% lower under the RDE tests compared to the WLTC tests, while the CO was 60% lower. The NOx values were 34% lower under the RDE testing, and appeared to be linked to the average acceleration. No link was seen for the maximum acceleration or deceleration, indicating that this is not a good indicator for test cycle emissions. The exclusion of cold start and idling decreased all RDE emissions. RPA (Relative Positive Acceleration) had little correlation with CO2, CO and NOx distancebased emissions, and was shown to be uncorrelated with any mass-rate emissions. The range of RPA values seen was much greater for RDE tests than WLTC tests, with individual RDE tests having variable values for each drive mode. The application of the MAW technique had minimal effect on the CO2 distance-based emission, but it appeared to decrease CO and NOx emissions by 12% and 21% on average respectively. The MAW also decreased the variation in emissions across different modes.

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Section: Introductionsupporting

confidence: 79%

Section: Emission Comparisonscontrasting

confidence: 52%

A Comparison of Tailpipe Gaseous Emissions for RDE and WLTC Using SI Passenger Cars

Thomas¹,

Li²,

Wang³

et al. 2017

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…However, it is complex to implement the SCR system onboard a vehicle, as it requires the deployment of a urea-dosing infrastructure with a urea tank, NO x /NH 3 catalysts, and sensors. To decrease the aftertreatment system dimensions under the vehicle's compartment, the SCR can be coated onto a DPF, and this type of solution is referred as an SCR-Catalyzed Diesel Particulate Filter (SDPF) [5,6].…”

Section: Introductionmentioning

confidence: 99%

Ammonia Concentration Distribution Measurements on Selective Catalytic Reduction Catalysts

2018

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This work presents the methodology and accurate evaluation of ammonia concentration distribution measurements at the selective catalytic reduction (SCR) catalyst outlet cross-section. The uniformity of ammonia concentration is a crucial factor influencing overall SCR effectiveness, and it contributes to the necessity of employing a reliable test method. The aftertreatment system design (mainly its geometrical features) can be evaluated in detail. The ammonia concentration is measured at the SCR catalyst outlet at grid points covering from the center to the outer edges of the catalyst. Its execution requires the introduction of a probe hovering over the back face of the SCR. To obtain the expected accuracy, it is necessary to measure a sufficient number of points in a reasonable timeframe. In order to achieve that, a fully automatic sampling device was developed. Sample results are presented showing the capabilities of the created test stand and its importance for the design development and validation stages of SCR-based engine aftertreatment.

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“…The divergence in laboratory and real-world NO x emission values was the core reason for introducing new amendments to the Euro 6 standard, which requires Original Equipment Manufacturer (OEM) to perform real-driving emissions (RDE) tests using portable emission measurement systems (PEMSs) for the approval of passenger cars in the Europe [5][6][7][8]. With RDE testing legally enforced in 2017, the OEM approach to exhaust system layouts of passenger cars will have to be thoroughly modified by implementing the SCR technology as a baseline solution for the CI engines.…”

Section: Introductionmentioning

confidence: 99%

Concept of Vaporized Urea Dosing in Selective Catalytic Reduction

2017

Self Cite

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This work tried to identify the influence of dosing vaporized urea solution in a selective catalytic reduction (SCR) system. In the SCR method, optimising the urea evaporation and mixing properties can significantly improve the NO x conversion efficiency in the catalyst. It can also exert a positive effect on the uniformity of NH 3 concentration distribution across the catalyst face. The concept of an electrically evaporated urea-dosing system was investigated and it was found that urea pre-heating prior to introduction into the exhaust gas is favourable for enhancing NO x removal under steady-state and transient engine operation. In the urea evaporating system the heating chamber was of a cylindrical tube shape and the urea vapour was introduced into the exhaust by means of a Venturi orifice. The concept urea dosing was only a custom-made solution, but proved to be superior to the regular dosing system operating in the liquid phase.

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Analysis of Emission Factors in RDE Tests As Well as in NEDC and WLTC Chassis Dynamometer Tests

Cited by 45 publications

References 16 publications

A Comparison of Tailpipe Gaseous Emissions for RDE and WLTC Using SI Passenger Cars

A Comparison of Tailpipe Gaseous Emissions for RDE and WLTC Using SI Passenger Cars

Ammonia Concentration Distribution Measurements on Selective Catalytic Reduction Catalysts

Concept of Vaporized Urea Dosing in Selective Catalytic Reduction

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