https://www.ermes-group.eu/web/system/files/filedepot/10/2013-JRC-Road-vehicle-emission-factors-development-A-review.pdf

Road vehicle emission factors development: A review

Laser-induced incandescence: Particulate diagnostics for combustion, atmospheric, and industrial applications

Review of motor vehicle particulate emissions sampling and measurement: From smoke and filter mass to particle number

. China's new "Twelfth Five-Year Plan" set a target for total NOx emission reduction of 10% for the period of 2011–2015. Heavy-duty diesel vehicles (HDDVs) have been considered a major contributor to NOx emissions in China. Beijing initiated a comprehensive vehicle test program in 2008. This program included a sub-task for measuring on-road emission profiles of hundreds of HDDVs using portable emission measurement systems (PEMS). The major finding is that neither the on-road distance-specific (g km−1) nor brake-specific (g kWh−1) NOx emission factors for diesel buses and heavy-duty diesel trucks improved in most cases as emission standards became more stringent. For example, the average NOx emission factors for Euro II, Euro III and Euro IV buses are 11.3 ± 3.3 g km−1, 12.5 ± 1.3 g km−1, and 11.8 ± 2.0 g km−1, respectively. No statistically significant difference in NOx emission factors was observed between Euro II and III buses. Even for Euro IV buses equipped with SCR systems, the NOx emission factors are similar to Euro III buses. The data regarding real-time engine performance of Euro IV buses suggest the engine certification cycles did not reflect their real-world operating conditions. These new on-road test results indicate that previous estimates of total NOx emissions for HDDV fleet may be significantly underestimated. The new estimate in total NOx emissions for the Beijing HDDV fleet in 2009 is 37.0 Gg, an increase of 45% compared to the previous study. Further, we estimate that the total NOx emissions for the national HDDV fleet in 2009 are approximately 4.0 Tg, higher by 1.0 Tg (equivalent to 18% of total NOx emissions for vehicle fleet in 2009) than that estimated in the official report. This would also result in 4% increase in estimation of national anthropogenic NOx emissions. More effective control measures (such as promotion of CNG buses and a new in-use compliance testing program) are urged to secure the goal of total NOx mitigation for the HDDV fleet in the future.

/pdf/the-challenge-to-no-x-emission-control-for-heavy-duty-diesel-3qk8gnro2e.pdf

The challenge to NO x emission control for heavy-duty diesel vehicles in China

An on-board vehicle emissions testing system includes an instrument module adapted to be detachably connected to the exhaust pipe of a vehicle to provide for flow of exhaust gas therethrough. The instrument module includes a differential pressure probe which allows for determination of flow rate of the exhaust gas and a gas sampling tube for continuously feeding a sample of the exhaust gas to a gas analyzer. In addition to the module, the on-board emission testing system also includes an elastomeric boot for detachably connecting the module to the exhaust pipe of the vehicle, a gas analyzer for receiving and analyzing gases sampled within the module and a computer for calculating pollutant mass flow rates based on concentrations detected by the gas analyzer and the detected flow rate of the exhaust gas. The system may also include a particulate matter detector with a second gas sampling tube feeding same mounted within the instrument module.

Real-time on-road vehicle exhaust gas modular flowmeter and emissions reporting system

There is considerable interest in portable emissions measurement systems (PEMS) for emission inventory and regulatory applications. For this study, four commercial PEMS were compared with a Federal Reference Method (FRM) for measuring emissions from a back-up generator (BUG) over steady-state loads and a diesel truck on transient and steady-state chassis dynamometer tests. The agreement between the PEMS and the FRM varied depending on the pollutant and the particular PEMS tested for both the BUG and chassis dynamometer testing. The best performing PEMS for both the BUG and chassis testing was within ∼12% for NOx of the FRM. For the BUG testing, several PEMS showed agreement with the FRM within ∼5% for CO2. For the chassis dynamometer testing, the best PEMS showed agreement typically within ∼5% for CO2. PM measurements for the BUG testing were low compared to the FRM, with the best measurements ∼20% lower. For the chassis testing, two PM PEMS showed a good correlation but a high bias, while the correlation...

Evaluation and Comparison of Portable Emissions Measurement Systems and Federal Reference Methods for Emissions from a Back-Up Generator and a Diesel Truck Operated on a Chassis Dynamometer

A method and apparatus for measuring vehicle exhaust emission includes sampling vehicle exhaust and a dilute mixture of vehicle exhaust and ambient air. A first analyzer measures concentrations of gas components of undiluted vehicle exhaust. A second analyzer measures concentration of at least one exhaust gas component present in the dilute mixture gas component. The at least one dilute mixture gas component is a particular exhaust gas component measured by the first analyzer which is also present in ambient air in substantial quantity. Flow rate of the dilute mixture, the concentration of the at least one dilute mixture gas component and undiluted gas concentration are analyzed by a microprocessor to produce mass emissions of the vehicle exhaust gas components.

Vehicle mass emission measurement

A vehicle gas emission analyzer assembly for a vehicle having a passenger compartment includes a gas analyzer system adapted to determine concentration and/or mass flow of at least one exhaust gas of an internal combustion engine. The analyzer may include a particular housing for the gas analyzer system. The gas analyzer system may include a hydrocarbon gas analyzer that is operated at a temperature that is sufficiently high to reduce deposits of hydrocarbon molecules present in the sample gas. The gas analyzer may include an ultraviolet source including a discharge lamp having a discrete emission line at an absorption frequency for a particular nitrogen-based gas.

Vehicle gas emission sampling and analysis assembly

A vehicle gas emission analyzer assembly for a vehicle having a passenger
compartment includes a gas analyzer system adapted to determine concentration
and/or mass flow of at least one exhaust gas of an internal combustion engine.
The analyzer may include a particular housing for the gas analyzer system. The
gas analyzer system may include a hydrocarbon gas analyzer that is operated at a
temperature that is sufficiently high to reduce deposits of hydrocarbon molecules
present in the sample gas. The gas analyzer may include an ultraviolet source
including a discharge lamp having a discrete emission line at an absorption
frequency for a particular nitrogen-based gas.

Vehicle emission sampling and analysis assembly

PROBLEM TO BE SOLVED: To provide a vehicle exhaust gas emission analyzer adapted to mounting to a vehicle. SOLUTION: A vehicle exhaust gas emission analyzer assembly (12) for a vehicle having a passenger compartment includes a gas analyzer system (18) adapted to determine concentration and/or mass flow of at least one type of exhaust gas of an internal combustion engine. The gas analyzer system (18) includes a particular housing (20) for the gas analyzer system. The gas analyzer system (18) includes a hydrocarbon gas analyzer (40) that is operated at temperature that is sufficiently high to reduce deposits of hydrocarbon molecules present in a sample gas. The gas analyzer (40) includes an ultraviolet source including a discharge lamp having a discrete emission line at an absorption frequency for a particular nitrogen-based gas. COPYRIGHT: (C)2002,JPO

Carl D. Ensfield

Papers

Evaluation and Comparison of Portable Emissions Measurement Systems and Federal Reference Methods for Emissions from a Back-Up Generator and a Diesel Truck Operated on a Chassis Dynamometer

Vehicle mass emission measurement

Vehicle gas emission sampling and analysis assembly

Vehicle emission sampling and analysis assembly

Vehicle exhaust gas emission sampling and analysis assembly