Experimental studies on the diesel engine urea-SCR system using a double NOx sensor system

Tang, Wu‐Neng; Cai, Yixi; Wang, Jun

doi:10.4491/eer.2015.097

Cited by 9 publications

(15 citation statements)

References 19 publications

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“…Like most chemical reactions, the three oxidation processes presented previously (2) require different activation energies, such that the reaction rates can change with temperature. Since the fractions of N 2 O , NO , and N O 2 generated by the ammonia oxidation processes change mainly according to the predominant oxidation reaction, the cross sensitivity factor will depend mainly on the temperature of the exhaust gases 26,27 and should range between 0.5 and 2. 22,26 Since the predominance of reactions equation (2) can be based on temperature, Hsieh and Wang 26 suggests that equation (2a) dominates at low temperatures and equation (2c) dominates at high temperatures.…”

Section: Methodsmentioning

confidence: 99%

NOx sensor cross sensitivity model and simultaneous prediction of NOx and NH3 slip from automotive catalytic converters under real driving conditions

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Bares

et al. 2020

International Journal of Engine Research

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This work presents the development of a model to capture the NOx sensors cross sensitivity behavior based on [Formula: see text] sensor cell temperature, as well as a model do predict the slip of the NOx and NH3 after the SCR catalyst, as a way to reduce the error in the exhaust emissions estimation needed for feedback SCR control strategies. The emissions prediction model is based on the different cross sensitivity behavior of two distinct NOx sensors. The proposed models were tested and compared on a fully instrumented engine test bench when applied in a Worldwide harmonized Light vehicles Test Cycle (WLTC) and a full map cycle. As a result, the proposed model showed for NOx sensors cross sensitivity estimation an overall improvement of 34.8% for sensor 1 and 31.0% for sensor 2, and in terms of emissions prediction an overall improvement of 36.3% for NOx and 45.5% for NH3 slip.

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Section: Methodsmentioning

confidence: 99%

NOx sensor cross sensitivity model and simultaneous prediction of NOx and NH3 slip from automotive catalytic converters under real driving conditions

Plá

Piqueras

Bares

et al. 2020

International Journal of Engine Research

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“…This study investigated an 1800 cc diesel engine with an SCR system for reducing NOx emissions. Figure 5 depicts the overall layout of the experimental setup, which includes a diesel engine, dynamometer, and SCR aftertreatment system [63]. The 4-cylinder diesel engine has an 18:1 compression ratio and a power output of 29 kW at 3000 rpm [63].…”

Section: Diesel Engine 1800 CCmentioning

confidence: 99%

Review of Improving the NOx Conversion Efficiency in Various Diesel Engines fitted with SCR System Technology

Wardana

2022

Catalysts

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The diesel engine is utilized in most commercial vehicles to carry items from various firms; nevertheless, diesel engines emit massive amounts of nitrogen oxides (NOx) which are harmful to human health. A typical approach for reducing NOx emissions from diesel engines is the selective catalytic reduction (SCR) system; however, several reasons make reducing NOx emissions a challenge: urea particles frequently become solid in the injector and difficult to disseminate across the system; the injector frequently struggles to spray the smaller particles of urea; the larger urea particles from the injector readily cling to the system; it is also difficult to evaporate urea droplets because of the exhaust and wall temperatures (Tw), resulting in an increase in solid deposits in the system, uncontrolled ammonia water solution injection, and NOx emissions problems. The light-duty diesel engine (LDD), medium-duty diesel engine (MDD), heavy-duty diesel engine (HDD), and marine diesel engine use different treatments to optimize NOx conversion efficiency in the SCR system. This review analyzes several studies in the literature which aim to increase NOx conversion in different diesel engine types. The approach and methods demonstrated in this study provide a suitable starting point for future research into reducing NOx emissions from diesel engines, particularly for engines with comparable specifications.

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“…Diesel vehicles, in general, emit low amounts of NH 3 . That said, diesel vehicles equipped with a urea-based selective catalytic reduction (SCR) system tend to encounter a problem referred to as "ammonia slip" emission [14]. Emissions from such vehicles, however, were not investigated in this study.…”

Section: Characteristics Of Gaseous Emissions From Vehicles Powered Bmentioning

confidence: 99%

Characterization of Emission Factors Concerning Gasoline, LPG, and Diesel Vehicles via Transient Chassis-Dynamometer Tests

et al. 2019

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Gaseous emissions from vehicles contribute substantially to air pollution and climate change. Vehicular emissions also contain secondary pollutants produced via chemical reactions that occur between the emitted gases and atmospheric air. This study aims at understanding patterns concerning emission of regulated, greenhouse, and precursor gases, which demonstrate potential for secondary aerosol (SA) formation, from vehicles incorporating different engine technologies—multi-point injection (MPI) and gasoline direct injection (GDI)—and using different fuels—gasoline, liquefied petroleum gas (LPG), and diesel. Drive cycles from the National Institute of Environmental Research (NIER) were used in this study. Results obtained from drive cycle tests demonstrate a decline in aggregate gas emissions corresponding to an increase in average vehicle speed. CO2 accounts for more than 99% of aggregate gaseous emissions. In terms of concentration, CO and NH3 form predominantly non-CO2 emissions from gasoline and LPG vehicles, whereas nitrogen oxides (NOx) and non-methane hydrocarbons (NMHC) dominate diesel-vehicle emissions. A higher percentage of SO2 is emitted from diesel vehicles compared to their gasoline- and LPG-powered counterparts. EURO-5- and EURO-6-compliant vehicles equipped with diesel particulate filters (DPFs) tend to emit higher amounts of NO2 compared to EURO-3-compliant vehicles, which are not equipped with DPFs. Vehicles incorporating GDI tend to emit less CO2 compared to those incorporating MPI, albeit at the expense of increased CO emissions. The authors believe that results reported in this paper concerning regulated and unregulated pollutant-emission monitoring can contribute towards an accurate evaluation of both primary and secondary air-pollution scenarios in Korea.

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Experimental studies on the diesel engine urea-SCR system using a double NOx sensor system

Cited by 9 publications

References 19 publications

NOx sensor cross sensitivity model and simultaneous prediction of NOx and NH3 slip from automotive catalytic converters under real driving conditions

NOx sensor cross sensitivity model and simultaneous prediction of NOx and NH3 slip from automotive catalytic converters under real driving conditions

Review of Improving the NOx Conversion Efficiency in Various Diesel Engines fitted with SCR System Technology

Characterization of Emission Factors Concerning Gasoline, LPG, and Diesel Vehicles via Transient Chassis-Dynamometer Tests

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