scholarly journals Particle and gaseous emissions from individual diesel and CNG buses

2013 ◽  
Vol 13 (10) ◽  
pp. 5337-5350 ◽  
Author(s):  
Å. M. Hallquist ◽  
M. Jerksjö ◽  
H. Fallgren ◽  
J. Westerlund ◽  
Å. Sjödin
Keyword(s):  
Emission Factors ◽  
Constant Speed ◽  
Particulate Filter ◽  
High Time Resolution ◽  
Exhaust Gas ◽  
Size Distributions ◽  
Gaseous Emissions ◽  
Diesel Buses ◽  
Speed Mode ◽  
Number Of Particles

Abstract. In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with a non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA3.1. The buses studied were diesel-fuelled Euro III–V and CNG-fuelled Enhanced Environmentally Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average a higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 4.4 ± 3.5 × 1014, EFPN, no DPF = 2.1 ± 1.0 × 1015 and EFPN, CNG = 7.8 ± 5.7 ×1015 kg fuel−1. In the accelerating mode, size-resolved emission factors (EFs) showed unimodal number size distributions with peak diameters of 70–90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode, bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)−1 and for the CNG buses 41 ± 26 g (kg fuel)−1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF, and there was a positive relationship between EFPM and EFCO.

scholarly journals Particle and gaseous emissions from individual diesel and CNG buses

2012 ◽  
Vol 12 (10) ◽  
pp. 27737-27773 ◽  
Author(s):  
Å. M. Hallquist ◽  
M. Jerksjö ◽  
H. Fallgren ◽  
J. Westerlund ◽  
Å. Sjödin
Keyword(s):  
Emission Factors ◽  
Constant Speed ◽  
Particulate Filter ◽  
High Time Resolution ◽  
Exhaust Gas ◽  
Size Distributions ◽  
Gaseous Emissions ◽  
Diesel Buses ◽  
Speed Mode ◽  
Number Of Particles

Abstract. In this study size-resolved particle and gaseous emissions from 28 individual diesel-fuelled and 7 compressed natural gas (CNG)-fuelled buses, selected from an in-use bus fleet, were characterised for real-world dilution scenarios. The method used was based on using CO2 as a tracer of exhaust gas dilution. The particles were sampled by using an extractive sampling method and analysed with high time resolution instrumentation EEPS (10 Hz) and CO2 with non-dispersive infrared gas analyser (LI-840, LI-COR Inc. 1 Hz). The gaseous constituents (CO, HC and NO) were measured by using a remote sensing device (AccuScan RSD 3000, Environmental System Products Inc.). Nitrogen oxides, NOx, were estimated from NO by using default NO2/NOx ratios from the road vehicle emission model HBEFA 3.1. The buses studied were diesel-fuelled Euro II–V and CNG-fuelled Enhanced Environmental Friendly Vehicles (EEVs) with different after-treatment, including selective catalytic reduction (SCR), exhaust gas recirculation (EGR) and with and without diesel particulate filter (DPF). The primary driving mode applied in this study was accelerating mode. However, regarding the particle emissions also a constant speed mode was analysed. The investigated CNG buses emitted on average higher number of particles but less mass compared to the diesel-fuelled buses. Emission factors for number of particles (EFPN) were EFPN, DPF = 8.0 ± 3.1 × 1014, EFPN, no DPF =2.8 ± 1.6 × 1015 and EFPN, CNG = 7.8 ± 5.7 × 1015 (kg fuel−1). In the accelerating mode size-resolved EFs showed unimodal number size distributions with peak diameters of 70–90 nm and 10 nm for diesel and CNG buses, respectively. For the constant speed mode bimodal average number size distributions were obtained for the diesel buses with peak modes of ~10 nm and ~60 nm. Emission factors for NOx expressed as NO2 equivalents for the diesel buses were on average 27 ± 7 g (kg fuel)−1 and for the CNG buses 41 ± 26 g (kg fuel)−1. An anti-relationship between EFNOx and EFPM was observed especially for buses with no DPF and there was a positive relationship between EFPM and EFCO.

scholarly journals UPDATING EMISSION FACTORS FOR IN-USE MOTORCYCLES FUELED BY GASOLINE, E5 AND E10 IN VIETNAM

2021 ◽  
Vol 11 (3) ◽  
pp. 199-206
Author(s):  
Pham Huu Tuyen ◽  
Pham Minh Tuan ◽  
Kazuhiro Yamamoto ◽  
Preechar Karin
Keyword(s):  
Particle Number ◽  
Combustion Engine ◽  
Low Cost ◽  
Emission Factors ◽  
Exhaust Gas ◽  
Gaseous Emissions ◽  
Chassis Dynamometer ◽  
Sampling System ◽  
Particulate Matter Emission ◽  
Long Time

Motorcycle is the most popular transportation means in Vietnam due to its low cost and flexibility. However, motorcycles emit substantial quantities of hydrocarbons, carbon monoxide, nitrogen oxides and some amount of particulate matter. Emission factors for in-use motorcycles in Vietnam were studied and established quite a long time ago. The objective of this study is to update the emission factors, not only gaseous emissions but also particle number, for in-use motorcycles in Vietnam. Ten carbureted and electronic fuel injected motorcycles representative for in-use motorcycles were selected for investigation. Each motorcycle was fueled by conventional gasoline, E5 and E10 in turn, and was tested on a chassis dynamometer according to ECE R40 driving cycle. The gaseous emissions were sampled and determined by standard methods, while the particle number in exhaust gas was sampled by using the sampling system developed by Laboratory of Internal Combustion Engine, Hanoi University of Science and Technology, Vietnam. The updated emission factors were then provided for carbureted motorcycles, EFI motorcycles and average motorcycle fleet in case of gasoline, E5 and E10 fueling.

On-Road Gaseous Emission Characteristics of the Bus Based on DOC + CDPF Technology

2013 ◽  
Vol 726-731 ◽  
pp. 2234-2240 ◽  
Author(s):  
Di Ming Lou ◽  
Si Li Qian ◽  
Zhi Yuan Hu ◽  
Pi Qiang Tan
Keyword(s):  
Emission Factors ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Particulate Filter ◽  
Testing System ◽  
Gaseous Emissions ◽  
Transient Operation ◽  
Operation Conditions ◽  
Emission Testing ◽  
Catalyzed Diesel Particulate Filter

In this paper, an experimental investigation was conducted using Vehicle Emission Testing System to study on-road gaseous emissions (CO, THC, NOX, CO2) characteristics based on diesel oxidation catalyst (DOC) and catalyzed diesel particulate filter (CDPF) technology. The results show that after the implementation of DOC + CDPF device, CO, THC emissions are significantly reduced, while the NOX, CO2 emissions remain almost the same. Under steady conditions, the reduction percentages of CO, THC, NOX, CO2 emission factors are 56.0%, 66.0%, 18.3%, 17.5%, respectively. Under transient operation conditions, the reduction percentages of CO, THC, NOX, CO2 emission factors are found to be 43.2%, 65.9%, 13.7%, 10.9%, respectively. Addition to the THC emission factor, the emission factors of CO, NOX and CO2 in transient operation conditions are higher than steady conditions.

scholarly journals Nanostructure changes in diesel soot during NO2–O2 oxidation under diesel particulate filter-like conditions toward filter regeneration

2018 ◽  
Vol 20 (8-9) ◽  
pp. 953-966 ◽  
Author(s):  
Madhu Singh ◽  
Mek Srilomsak ◽  
Yujun Wang ◽  
Katsunori Hanamura ◽  
Randy Vander Wal
Keyword(s):  
Diesel Particulate Filter ◽  
Surface Oxidation ◽  
Soot Oxidation ◽  
Diesel Soot ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Fringe Analysis ◽  
Diesel Particulate ◽  
Oxidation Rates ◽  
Passive Regeneration

Development of the regeneration process on diesel particulate filters requires a better understanding of soot oxidation phenomena, especially its relation to soot nanostructure. Nitrogen dioxide (NO2) is known to play an essential role in passive regeneration by oxidizing soot at low temperatures, especially in the presence of oxygen (O2) in the exhaust. However, change in soot nanostructure due to oxidation by NO2–O2 mixtures has not received much attention. This work focuses on nanostructure evolution during passive regeneration of the diesel particulate filter by oxidation of soot at normal exhaust gas temperatures (300°C–400°C). High-resolution transmission electron microscopy of partially oxidized model carbons (R250, M1300, arc-generated soot) and diesel soot under NO2–O2 mixtures is used to investigate physical changes in nanostructure correlating with the material’s behavior during oxidation. Microscopy reveals the changing nanostructure of model carbons during oxidation while fringe analysis of the images points to the differences in the structural metrics of fringe length and tortuosity of the resultant structures. The variation in oxidation rates highlights the inter-dependence of the material’s reactivity with its structure. NO2 preferentially oxidizes edge-site carbon, promotes surface oxidation by altering the particle’s burning mode with increased overall reactivity of NO2+O2 resulting in inhibition of internal burning, typically observed by O2 at exhaust gas temperatures.

Effect of ejector dilutors on measurements of automotive exhaust gas aerosol size distributions

2009 ◽  
Vol 20 (4) ◽  
pp. 045703 ◽  
Author(s):  
Barouch Giechaskiel ◽  
Leonidas Ntziachristos ◽  
Zissis Samaras
Keyword(s):  
Exhaust Gas ◽  
Size Distributions ◽  
Automotive Exhaust

scholarly journals A Study on Characteristic Emission Factors of Exhaust Gas from Diesel Locomotives

2020 ◽  
Vol 17 (11) ◽  
pp. 3788 ◽  
Author(s):  
Min-Kyeong Kim ◽  
Duckshin Park ◽  
Minjeong Kim ◽  
Jaeseok Heo ◽  
Sechan Park ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Environmental Protection Agency ◽  
High Speed ◽  
Emission Factors ◽  
Exhaust Emission ◽  
Emission Measurement ◽  
Exhaust Gas ◽  
Diesel Locomotive ◽  
Diesel Vehicles ◽  
Engine Power

Use of diesel locomotives in transport is gradually decreasing due to electrification and the introduction of high-speed electric rail. However, in Korea, up to 30% of the transportation of passengers and cargo still uses diesel locomotives and diesel vehicles. Many studies have shown that exhaust gas from diesel locomotives poses a threat to human health. This study examined the characteristics of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons in diesel locomotive engine exhaust. Emission concentrations were evaluated and compared with the existing regulations. In the case of PM and NOx, emission concentrations increased as engine output increased. High concentrations of CO were detected at engine start and acceleration, while hydrocarbons showed weakly increased concentrations regardless of engine power. Based on fuel consumption and engine power, the emission patterns of PM and gaseous substances observed in this study were slightly higher than the U.S. Environmental Protection Agency Tier standard and the Korean emission standard. Continuous monitoring and management of emissions from diesel locomotives are required to comply with emission standards. The findings of this study revealed that emission factors varied based on fuel consumption, engine power, and actual driving patterns. For the first time, a portable emission measurement system (PEMS), normally used to measure exhaust gas from diesel vehicles, was used to measure exhaust gas from diesel locomotives, and the data acquired were compared with previous results. This study is meaningful as the first example of measuring the exhaust gas concentration by connecting a PEMS to a diesel locomotive, and in the future, a study to measure driving characteristics and exhaust gas using a PEMS should be conducted.

scholarly journals Late Fuel Post-Injection Influence on the Dynamics and Efficiency of Wall-Flow Particulate Filters Regeneration

2019 ◽  
Vol 9 (24) ◽  
pp. 5384 ◽  
Author(s):  
José Ramón Serrano ◽  
Pedro Piqueras ◽  
Joaquín de la Morena ◽  
Enrique José Sanchis
Keyword(s):  
Fuel Consumption ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Post Injection ◽  
Gas Temperature ◽  
Diesel Particulate ◽  
Particulate Filters ◽  
Exhaust Temperature ◽  
Injection Parameters ◽  
Wall Flow

Late fuel post-injections are the most usual strategy to reach high exhaust temperature for the active regeneration of diesel particulate filters. However, it is important to optimise these strategies in order to mitigate their negative effect on the engine fuel consumption. This work aims at understanding the influence of the post-injection parameters, such as its start of injection and its fuel quantity, on the duration of the regeneration event and the fuel consumption along it. For this purpose, a set of computational models are employed to figure out in a holistic way the involved phenomena in the interaction between the engine and the exhaust gas aftertreatment system. Firstly, an engine model is implemented to evaluate the effect of the late fuel post-injection pattern on the gas properties at the exhaust aftertreatment system inlet in different steady-state operating conditions. These are selected to provide representative boundary conditions of the exhaust gas flow concerning dwell time, exhaust temperature and O 2 concentration. In this way, the results are later applied to the analysis of the diesel oxidation catalyst and wall-flow particulate filter responses. The dependence of the diesel particulate filter (DPF) inlet temperature is discussed based on the efficiency of each post-injection strategy to increase the exhaust gas temperature. Next, the influence on the dynamics of the regeneration of the post-injection parameters through the change in gas temperature and O 2 concentration is finally studied distinguishing the pre-heating, maximum reactivity and late soot oxidation stages as well as the required fuel consumption to complete the regeneration process.

Effect of the Fuel Injection Strategy on Diesel Particulate Filter Regeneration in a Single-Cylinder Diesel Engine

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Sungjun Yoon ◽  
Hongsuk Kim ◽  
Daesik Kim ◽  
Sungwook Park
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Diesel Particulate ◽  
Injection Strategy ◽  
Dpf Regeneration ◽  
Exhaust Gas Temperature

Stringent emission regulations (e.g., Euro-6) have forced automotive manufacturers to equip a diesel particulate filter (DPF) on diesel cars. Generally, postinjection is used as a method to regenerate the DPF. However, it is known that postinjection deteriorates the specific fuel consumption and causes oil dilution for some operating conditions. Thus, an injection strategy for regeneration is one of the key technologies for diesel powertrains equipped with a DPF. This paper presents correlations between the fuel injection strategy and exhaust gas temperature for DPF regeneration. The experimental apparatus consists of a single-cylinder diesel engine, a DC dynamometer, an emission test bench, and an engine control system. In the present study, the postinjection timing was in the range of 40 deg aTDC to 110 deg aTDC and double postinjection was considered. In addition, the effects of the injection pressure were investigated. The engine load was varied among low load to midload conditions, and the amount of fuel of postinjection was increased up to 10 mg/stk. The oil dilution during the fuel injection and combustion processes was estimated by the diesel loss measured by comparing two global equivalences ratios: one measured from a lambda sensor installed at the exhaust port and one estimated from the intake air mass and injected fuel mass. In the present study, the differences of the global equivalence ratios were mainly caused by the oil dilution during postinjection. The experimental results of the present study suggest optimal engine operating conditions including the fuel injection strategy to obtain an appropriate exhaust gas temperature for DPF regeneration. The experimental results of the exhaust gas temperature distributions for various engine operating conditions are discussed. In addition, it was revealed that the amount of oil dilution was reduced by splitting the postinjection (i.e., double postinjection). The effects of the injection pressure on the exhaust gas temperature were dependent on the combustion phasing and injection strategies.

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