Modeling Enleanment Emissions for Light-Duty Vehicles

1998 ◽  
Vol 1641 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Feng An ◽  
Matthew Barth ◽  
George Scora ◽  
Marc Ross
Keyword(s):  
Test Procedure ◽  
Model Development ◽  
Environmental Research ◽  
Load Reduction ◽  
Lean Burn ◽  
Emission Data ◽  
Light Duty ◽  
Hc Emissions ◽  
College Of Engineering ◽  
Light Duty Vehicles

A comprehensive modal emissions model for light-duty cars and trucks is being developed under the sponsorship of NCHRP Project 25-11. Model development has been described previously for vehicles operating under stoichiometric and enrichment conditions. A modal emissions model is presented for vehicles operated under enleanment conditions. Enleanment typically occurs with sharp deceleration or load reduction events, and sometimes during long deceleration. Under enleanment conditions, the air/fuel ratio is lean and incomplete combustion or misfire occurs. Preliminary research indicates that enleanment emissions (particularly for hydrocarbons) contribute significantly to a vehicle’s overall emissions. An enleanment emissions module has been developed on the basis of second-by-second emission measurements generated at the College of Engineering—Center for Environmental Research and Technology’s vehicle testing facility using the Federal Test Procedure, US06, and a specially designed modal emission cycle (MEC01). On the basis of more than 200 vehicles tested and modeled, lean-burn hydrocarbon emissions (HClean) account for 10 to 20 percent of the overall HC emissions under the various test cycles. HClean emission contributions vary greatly from vehicle to vehicle, ranging from near 0 to more than 30 percent of total HC emissions of individual vehicles. After detailed analysis of the second-by-second emission data over the modal emission cycle MECO1, it was found that enleanment hydrocarbons emissions are mostly associated with rapid load reduction events and long deceleration events. The former is most likely to cause extremely high levels of HC as short spikes, and the latter is mostly associated with longer-lasting HC puffs. A methodology has been developed to characterize and model enleanment hydrocarbons emissions associated with these two events. The model estimates are compared with measurements, with encouraging results.

Measurement and Evaluation of Real-World Speed and Acceleration Activity Envelopes for Light-Duty Vehicles

2015 ◽  
Vol 2503 (1) ◽  
pp. 128-136 ◽  
Author(s):  
Bin Liu ◽  
H. Christopher Frey
Keyword(s):  
Real World ◽  
Test Procedure ◽  
Accurate Estimation ◽  
Vehicle Type ◽  
Light Duty ◽  
Road Grade ◽  
Light Duty Vehicle ◽  
Curb Weight ◽  
Vehicle Activity ◽  
Light Duty Vehicles

Accurate estimation of vehicle activity is critically important for the accurate estimation of emissions. To provide a benchmark for estimation of vehicle speed trajectories such as those from traffic simulation models, this paper demonstrates a method for quantifying light-duty vehicle activity envelopes based on real-world activity data for 100 light-duty vehicles, including conventional passenger cars, passenger trucks, and hybrid electric vehicles. The vehicle activity envelope was quanti-fied in the 95% frequency range of acceleration for each of 15 speed bins with intervals of 5 mph and a speed bin for greater than 75 mph. Potential factors affecting the activity envelope were evaluated; these factors included vehicle type, transmission type, road grade, engine displacement, engine horsepower, curb weight, and ratio of horsepower to curb weight. The activity envelope was wider for speeds ranging from 5 to 20 mph and narrowed as speed increased. The latter was consistent with a constraint on maximum achievable engine power demand. The envelope was weakly sensitive to factors such as type of vehicle, type of transmission, road grade, and engine horsepower. The effect of road grade on cycle average emissions rates was evaluated for selected real-word cycles. The measured activity envelope was compared with those of dynamometer driving cycles, such as the federal test procedure, highway fuel economy test, SC03, and US06 cycles. The effect of intervehicle variability on the activity envelope was minor; this factor implied that the envelope could be quantified based on a smaller vehicle sample than used for this study.

scholarly journals Analysis of the influence of RDE test data processing methods on the emission results of China 6 light duty vehicles

2021 ◽  
Vol 268 ◽  
pp. 01022
Author(s):  
Zhihong Wang ◽  
Penghui Wu ◽  
Nenghui Yu ◽  
Yuanjun Zhang ◽  
Zhijun Wang
Keyword(s):  
Data Processing ◽  
Test Data ◽  
Emission Factor ◽  
Vehicle Emission ◽  
Emission Data ◽  
Processing Methods ◽  
Light Duty ◽  
Light Duty Vehicle ◽  
Light Duty Vehicles ◽  
Data Processing Methods

The CO2 moving average window(MAW) method is used to process RDE (real drive emissions) emissions data in China 6 light duty vehicle emissions regulations, while the Euro 6 light duty vehicle emission regulations allow to use both of MAW and power binning(PB) method to deal with RDE emission data. In order to study the difference between the two data processing methods and analyze the differences in the emission results, 10 different types of light duty vehicles are conducted RDE test with PEMS (portable emissions measurement system), and the test data are processed by the two methods separately. The results show that there is a little difference between MAW and PB, while both of them can satisfy the vehicle emission assessment. The PB method calculates the emission factors higher than the MAW method. After removing the cold start and idle condition data, the results of PB is similar to MAW. Besides, reducing the average speed limit of urban working conditions in PB has a greater impact on the urban driving condition emission factor, but less on the whole cycle emission factor.

Development of the Worldwide Harmonized Test Procedure for Light-Duty Vehicles

2015 ◽  
Vol 2503 (1) ◽  
pp. 110-118 ◽  
Author(s):  
Biagio Ciuffo ◽  
Alessandro Maratta ◽  
Monica Tutuianu ◽  
Konstantinos Anagnostopoulos ◽  
Georgios Fontaras ◽  
...  
Keyword(s):  
Carbon Dioxide Emissions ◽  
Test Procedure ◽  
Test Results ◽  
Test Cycle ◽  
Test Procedures ◽  
United Nations Economic Commission ◽  
Vehicle Performance ◽  
Light Duty ◽  
Economic Commission ◽  
Light Duty Vehicles

To assess vehicle performance on criteria compounds, carbon dioxide emissions, and fuel energy consumption, laboratory tests are generally carried out. During these tests, a vehicle is driven on a chassis dynamometer (which simulates the resistances the vehicle encounters during its motion) to follow a predefined test cycle. In addition, all conditions for running a test must strictly adhere to a predefined test procedure. The procedure is necessary to ensure that all tests are carried out in a comparable way, following the requirements set by the relevant legislation. Test results are used to assess vehicle compliance with emissions limits or to evaluate the fuel consumption that will be communicated to customers. Every region in the world follows its own approach in carrying out these types of tests. The variations in approaches have resulted in a series of drawbacks for vehicle manufacturers and regulating authorities, leading to a plethora of different conditions and results. As a step toward the harmonization of the test procedures, the United Nations Economic Commission for Europe launched a project in 2009 for the development of a worldwide harmonized light-duty test procedure (WLTP), including a new test cycle. The objective of the study reported here was to provide a brief description of WLTP and outline the plausible pathway for its introduction in European legislation.

scholarly journals Gaseous Emissions from Light-Duty Vehicles: Moving from NEDC to the New WLTP Test Procedure

2015 ◽  
Vol 49 (14) ◽  
pp. 8315-8322 ◽  
Author(s):  
Alessandro Marotta ◽  
Jelica Pavlovic ◽  
Biagio Ciuffo ◽  
Simone Serra ◽  
Georgios Fontaras
Keyword(s):  
Test Procedure ◽  
Gaseous Emissions ◽  
Light Duty ◽  
Light Duty Vehicles

scholarly journals Characterization of Exhaust CO, HC and NOx Emissions from Light-Duty Vehicles under Real Driving Conditions

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1125
Author(s):  
Hui Mei ◽  
Lulu Wang ◽  
Menglei Wang ◽  
Rencheng Zhu ◽  
Yunjing Wang ◽  
...  
Keyword(s):  
Specific Power ◽  
Emission Measurement ◽  
Nox Emissions ◽  
Emission Rates ◽  
Gaseous Emissions ◽  
Passenger Cars ◽  
Light Duty ◽  
Driving Conditions ◽  
Hc Emissions ◽  
Light Duty Vehicles

On-road exhaust emissions from light-duty vehicles are greatly influenced by driving conditions. In this study, two light-duty passenger cars (LDPCs) and three light-duty diesel trucks (LDDTs) were tested to investigate the on-road emission factors (EFs) with a portable emission measurement system. Emission characteristics of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) emitted from vehicles at different speeds, accelerations and vehicle specific power (VSP) were analyzed. The results demonstrated that road conditions have significant impacts on regulated gaseous emissions. CO, NOx, and HC emissions from light-duty vehicles on urban roads increased by 1.1–1.5, 1.2–1.4, and 1.9–2.6 times compared with those on suburban and highway roads, respectively. There was a rough positive relationship between transient CO, NOx, and HC emission rates and vehicle speeds, while the EFs decreased significantly with the speed decrease when speed ≤ 20 km/h. The emissions rates of NOx and HC tended to increase and then decrease as the acceleration increased and the peak occurred at 0 m/s2 without considering idling conditions. For HC and CO, the emission rates were low and changed gently with VSP when VSP < 0, while emission rates increased gradually with the VSP increase when VSP > 0. For NOx NOx emission rates were lower and had no obvious change when VSP < 0. However, NOx emissions were positively correlated with VSP, when VSP > 0.

Research for NOx Emission of Nanjing Vehicle Based on IVE Model

2011 ◽  
Vol 99-100 ◽  
pp. 1341-1345 ◽  
Author(s):  
Jun Liu ◽  
Jing Jing Dong ◽  
Xiao Peng Shi ◽  
Hui Zhong Wang ◽  
Hao Ming Yang
Keyword(s):  
Correction Factors ◽  
Road Vehicles ◽  
Emission Data ◽  
Light Duty ◽  
Different Types ◽  
Nanjing City ◽  
Vehicles Emissions ◽  
Driving Condition ◽  
Light Duty Vehicles ◽  
Ive Model

This paper researched on vehicles’ emissions in Nanjing based on IVE model and presented the method to quantify the main inputting parameters of IVE model. This research has collected the traffic of different types of roads in Nanjing. The light-duty vehicles, taxis, buses and trucks respectively accounted for 73.4%, 13.3%, 10.3% and 3.0% of the total traffic volume. According to vehicle driving condition data collected by GPS, the driving cycle of light-duty vehicles in Nanjing was defined. The on-road vehicles’ emission data were measured using the on-board vehicle emission analyzer made by ourselves. Then the correction factors of NOx in IVE model could be obtained using the testing emission data. The results of IVE model showed that the daily NOx emission of light-duty vehicles, taxis, buses and trucks in Nanjing city were 17.79t, 5.51t, 146.37t and 83.78t. Buses and trucks were the main emission sources of NOx, with the contribution of 57.75% and 33.06%.

Dealing with the Gap between Type-Approval and In-Use Light Duty Vehicles Fuel Consumption and CO2 Emissions: Present Situation and Future Perspective

2018 ◽  
Vol 2672 (2) ◽  
pp. 23-32 ◽  
Author(s):  
Jelica Pavlovic ◽  
Konstantinos Anagnostopoulos ◽  
Michael Clairotte ◽  
Vincenzo Arcidiacono ◽  
Georgios Fontaras ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Real World ◽  
Test Procedure ◽  
Present Situation ◽  
Future Perspective ◽  
Type Approval ◽  
Real Driving Emission ◽  
Light Duty ◽  
The Difference ◽  
Light Duty Vehicles

There is increasing evidence suggesting that real-world fuel consumption and CO2 improvements in the last decade have been much less than those measured during type-approval tests. Scientific studies have found that the offset between officially reported values and real-world vehicle CO2 emissions in Europe has constantly increased over the last years. The difference between officially reported and actual CO2 emissions of vehicles has three main implications: (i) it undermines the effectiveness of CO2 regulations in reducing greenhouse gas emissions in Europe; (ii) it distorts competition between vehicle manufacturers; (iii) it undermines innovation. As a fundamental step to deal with this issue, the European Commission has already replaced the old and outdated test procedure used so far in the emission type-approval of vehicles with the worldwide harmonized light vehicles test procedure (WLTP). Being a lab-based test procedure, the WLTP, by its nature, can only cover part of the CO2 gap. There is therefore increasing pressure to integrate the current type-approval system with additional measures based on real-world measurements. One of the options under discussion is to use the CO2 emissions measured during the real driving emission test. The objective of the present paper is to assess the validity of this proposal and to propose other possible ways to deal with the CO2/fuel consumption gap. In particular, the paper presents experimental evidence on the variability of the CO2/fuel consumption of a vehicle, questioning the idea that a single central estimate of these quantities may be sufficient.

scholarly journals Impacts of the New Worldwide Light-Duty Test Procedure on Technology Effectiveness and China’s Passenger Vehicle Fuel Consumption Regulations

2021 ◽  
Vol 18 (6) ◽  
pp. 3199
Author(s):  
Kangda Chen ◽  
Fuquan Zhao ◽  
Xinglong Liu ◽  
Han Hao ◽  
Zongwei Liu
Keyword(s):  
Fuel Consumption ◽  
Electric Vehicles ◽  
Test Procedure ◽  
Gasoline Direct Injection ◽  
Chinese Government ◽  
Chinese Market ◽  
Lean Burn ◽  
Light Duty ◽  
Technology Effectiveness ◽  
The Government

As a main measure to promote the development of China’s energy–saving and new energy vehicles, the Phase V fuel consumption regulation is dramatically different from the past four phases, especially in the test procedure, moving from the New European Driving Cycle (NEDC) to the worldwide harmonized light duty test cycle (WLTC) and corresponding test procedure (WLTP). The switch of test procedure will not only affect the effectiveness of technologies but also change the fuel consumption target of the industry. However, few studies have systematically investigated the impacts of the new WLTP on the Chinese market. This study establishes a “technology–vehicle–fleet” bottom–up framework to estimate the impacts of test procedure switching on technology effectiveness and regulation stringency. The results show that due to the WLTP being closer to the real driving condition and more stringent, almost all baseline vehicles in the WLTP have higher fuel consumption than that in the NEDC, and diesel vehicles are slightly more impacted than gasoline vehicles. In addition, the impacts are increased with the strengthening of electrification, where the fuel consumption of plug–in hybrid electric vehicles (PHEVs) and range-extended electric vehicles (REEVs) in the WLTP are about 6% higher than that in the NEDC. Engine technologies that gain higher effects in low load conditions, such as turbocharging and downsizing, fuel stratified injection (FSI), lean–burn, and variable valve timing (VVT), are faced with deterioration in the WLTP. Among these, the effect of turbocharging and downsizing shows a maximum decline of 8.5%. The variable compression ratio (VCR) and stoichiometric gasoline direct injection (SGDI) are among the few technologies that benefited from procedure switching, with an average improvement of 1.6% and 0.2% respectively. Except for multi–speed transmissions, which have improvement effects in the WLTP, all automatic transmissions are faced with decreases. From the perspective of the whole fleet and national regulation target, the average fuel consumption in the WLTP will increase by about 7.5% in 2025 compared to 4 L/100 km in the NEDC. According to the current planning of the Chinese government, the fuel consumption target of Phase V is set at 4.6 L/100 km in 2025, which is equivalent to loosening the stringency by 0.3 L/100 km. In Phase VI, the target of 3.2 L/100 km is maintained, which is 30.4% stricter than that of Phase V, and the annual compound tightening rate reaches 7.5%. This means that automakers need to launch their product planning as soon as possible and expand the technology bandwidth to comply with the Phase VI fuel consumption regulation, and the government should evaluate the technical feasibility before determining the evaluation methods and targets of the next phase.

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