Wyniki wyszukiwania - BazTech

1

Numerical analysis of heat conduction influence on SCR aftertreatment systems EFF

Bachanek J., Rogóż R., Teodorczyk A.

Journal of KONES

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2018

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Vol. 25, No. 3

51--58

EN

Selective Catalytic Reduction (SCR) is well known method for reducing NOx emission in diesel engine exhaust gas. Urea-water solution (UWS) injected into hot stream decomposes due to thermolysis into ammonia and isocyanic acid which hydrolyses further into more ammonia and carbon dioxide. Resultant ammonia is the NOx reductor, producing water vapour and carbon dioxide from the reduction reaction. To provide sufficient NOx reduction efficiency, UWS needs to be properly atomized and mixed with exhaust gas. However, due to more and more restrictive emissions regulations provided by European Union and Close Coupled trend of aftertreatment systems in vehicles the design process is very complex and demanding. Computational Fluid Dynamics (CFD) simulations are integral part of product development, allowing save time and reduce costs of preparing prototypes for further tests. However, it is necessary to understand all the processes and problems connected with NOx reduction in SCR system. Strong turbulent flow of hot stream gas, urea-water solution spray injection, droplets interaction with wall, wallfilm generation are included. The objective of this work is to investigate the impact of heat transfer modelling inside mixing elements of SCR system on urea mixing uniformity and wallfilm deposit on the walls of the system. Simplified and more complex approach is compared with no heat transfer cases. All the simulations were conducted using AVL FIRETM software. Results showed that wall heat transfer might have an impact on mixing efficiency and wallfilm formulation. It is necessary to take into account the effect of mixing elements heat conduction in CFD simulations during the aftertreatment design process.

2

SCR systems for NOx reduction in heavy and light duty vehicles

Jaworski P., Jarosiński S., Cortes Capetillo A., Kapusta Ł. J., Ziółkowski A., Grzywnowicz R.

Combustion Engines

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2016

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R. 55, nr 1

32--36

EN

Air pollution has become an important worldwide problem. The European Commission credits road and water transport as the major source of NOx pollution, and of being responsible for around 50% of the total air pollution in urban areas. During the last decade, the use of SCR technologies have gained popularity as a method for NOx reduction, the technology is widely considered as one of the solutions for road transport emissions. This paper presents a review of the different SCR system designs derived from the various factors and regulations in the automotive industry which have influenced the technology, along with a parametric study of a proprietary SCR system for heavy duty application.

3

Directions in vehicle efficiency and emissions

Johnson T. V., Joshi A.

Combustion Engines

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2016

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R. 55, nr 3

3--8

EN

This paper provides a general review of light-duty (LD) and heavy-duty (HD) regulations, engine technology, and key emission control strategies. The US is placing a stronger emphasis on laboratory emissions, and the LD regulations are about an order of magnitude tighter than Euro 6, but Europe is focusing on real-world reductions. The California HD low-NOx regulation is advancing and may be proposed in 2017/18 for implementation in 2023+. The second phase of US HD greenhouse gas regulations propose another 25-30% tightening beyond Phase 1, beginning in 2021. LD and HD engine technology continues showing marked improvements in engine efficiency. LD gasoline concepts are closing the gap with diesel. HD engines are demonstrating more than 50% BTE using methods that can reasonably be commercialized. LD and HD diesel NOx technology trends are also summarized. NOx storage catalysts and SCR combinations are the lead approach to meeting the LD regulations. Numerous advanced NOx technologies are being evaluated and some promise for meeting the California HD low NOx targets. Oxidation catalysts are improved for both diesel and methane oxidation applications. Gasoline particulate filters (GPF) are the lead approach to reducing particles from gasoline direct injection (GDI) engines. They reduce PAH emissions, and catalyzed versions can be designed for low back pressure. Regeneration largely occurs during hot decelerations.

4

SCR systems for NOx reduction in heavy duty vehicles

Jaworski P., Kapusta Ł. J., Jarosiński S., Ziółkowski A., Cortes Capetillo A., Grzywnowicz R.

Journal of KONES

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2015

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Vol. 22, No. 4

139--146

EN

Air pollution has become an important worldwide problem. The European Commission credits road and water transport as the major source of NOx pollution, and of being responsible for around 50% of the total air pollution in urban areas. In Poland, around 45% of the country NOx emissions are attributed to transportation. During the last decade, the use of SCR technologies have gained popularity as a method for NOx reduction, the technology is widely considered as one of the solutions for road transport emissions. SCR technology had previously been employed in stationary plants, maritime transportation and other installations using combustion processes in which exhaust conditions are easier to control. The advance on the technology led to the introduction of the first heavy-duty vehicle with an SCR system into the market in 2004. New technologies and applications are constantly appearing, for example, SCR exhaust gas cleaning systems for reciprocating engines are still under development and compression ignition engines can be found in a number of different applications. The technology still needs to be studied and improved as constant problems and knowledge is required in issues such as urea injection, crystallization and NOx reduction efficiency. Moreover, the designs intended for heavy duty vehicles need to meet vehicle limitations and EURO emissions restrictions. This paper presents a review of the different SCR system designs derived from the various factors and regulations in the automotive industry, which have influenced the technology, along with a parametric study of a proprietary SCR system for heavy-duty application.

5

Analysis of current and future trends in automotive emissions, fuels, lubricants and test methods : (perspectives from the 2nd International Exhaust Emissions Symposium, 25/26 May 2011)

Bielaczyc P., Woodburn J.

Silniki Spalinowe

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2011

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R. 50, nr 4

104-118

EN

BOSMAL hosted the 2nd International Exhaust Emissions Symposium, entitled Current and future trend s in automotive emissions, fuels, lubricants and test methods, which featured a total of eighteen presentations from experts on automotive emissions and after treatment and the fuel and lubricant industries. The symposium's technical programme consisted of two keynote lectures and four themed presentation sessions. The symposium also featured the opening of new engine test cells at BOSMAL. The entire event was an unqualified success, building on the achievements of the previous year's event. Some of the most important trend s mentioned during the symposium included: changes to test procedures to reflect the challenge of quantifying ever decreasing emission levels, as well as measuring new compounds, the continued key role of catalytic after treatment systems in achieving low emission levels of gaseous pollutants and particulate matter, and the potential role for electrified powertrains and alternative fuels from various sources to meet our transportation energy need's over the coming decades.

6

Possibilities of application of nanostructural materials in exhaust gas aftertreatment

Merkisz J., Fuć P.

Silniki Spalinowe

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2009

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R. 48, SC1

109--114

EN

There is no doubt that the share of newly registered vehicles fitted with combustion engines will grow, particularly those fitted with diesel engines for their much lower fuel consumption. Due to the specificity of the diesel engines and the issues related to NOx and PM emission, continuous research is being done in order to reduce those emissions. Investigations continue to implement new technologies such as the addition of urea into the exhaust gases to generate a NOx reducing atmosphere or to reduce the maximum temperature of PM ignition. Another rapidly developing branch is nanotechnology and thermoelectric materials. The article presents the possibility of application of nanostructural materials in order to increase the environment friendliness of certain vehicle subassemblies.

PL

Nie ulega wątpliwości, że silniki spalinowe a szczególnie silniki o zapłonie samoczynnym, z uwagi na dużo mniejsze zużycie paliwa w stosunku do silników o zapłonie iskrowym, będą zajmowały coraz większy udział w rynku samochodów nowosprzedawanych jak i będących w eksploatacji. Ze względu na specyfikę pracy tych silników i problem z emisją tlenków azotu i cząstek stałych w sposób ciągły prowadzi się badania mające na celu ograniczenie tej emisji. Prowadzi się badania nad wprowadzeniem nowych technologii, jaką na przykład jest dodawanie roztworu amoniaku do gazów wylotowych w celu stworzenia atmosfery redukującej w układzie wylotowym czy też prowadzenie do zmniejszenia maksymalnej temperatury zapłonu cząstek stałych. Inną dynamicznie rozwijająca się gałęzią nowych rozwiązań jest zastosowanie nanotechnologii i materiałów termoelektrycznych. W artykule przedstawiono możliwości zastosowania materiałów otrzymanych metodami pozwalającymi na uzyskanie nonostruktur w celu zwiększenia ekologiczności wybranych podzespołów pojazdów.

7

The effect of the catalytic converter modified with the nanoparticles on the emission from the light and heavy duty engines

Merkisz J., Fuć P., Lijewski P.

Logistyka

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2008

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nr 2

EN

In this paper a new concept of layers of the catalytic converter has been presented that allows to increase the contact area of reagents originating in exhaust gas and to rise the catalytic deposit temperature to the value which makes possible to extend the converter operation range in order to reduce the emission of nitrogen oxides and particular matter. Moreover, the results of examination of the catalytic converter tested at the engine test according to test bed for different catalytic blocks has been presented. Ten different combinations of the catalytic blocks have been subject to the examination and each combination included the basic composition in a form of aluminum oxide and platinum and some modified deposits consisting of different contents of palladium, ruthenium and nano-structure of cerium-zirconium oxides / ruthenium in a form of spheres.

8

Future development trends of HD diesel engines

Stępień Z., Oleksiak S.

Silniki Spalinowe

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2007

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R. 46, nr SC1

50-60

EN

The review of HD Diesel engines development trends including construction changes enabling fulfilling current and future emission limits was presented. In short the combustion systems, injection systems, turbocharging, EGR and dominating aftertreatment solutions were described.