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Tytuł:
Degrading mechanisms of selective catalytic reduction systems
Mechanizmy degradacji systemów selektywnej katalitycznej redukcji (SCR)
Autorzy:
Herdzik, J.
Powiązania:
https://bibliotekanauki.pl/articles/360777.pdf
Data publikacji:
2011
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
kontrola emisji spalin
wymogi tier 3
selektywna katalityczna redukcja (SCR)
mechanizmy degradacji systemów SCR
emission control
tier 3
selective catalytic reduction
degrading mechanisms of SCR
Opis:
It was presented problems of fulfillment the IMO tier 3 requirements. The proposition of using selective catalytic reduction was very interesting, but provided to many maintenance problems due to the degrading mechanisms of that systems. Some of those mechanisms were presented. It provided to degradation of those systems and worsening their emission reduction possibilities. The certificate of EIAPP may not tell the truth. It needs periodical surveys (minimum one per year) for checking the validity of issued EIAPP certificate. A SCR system would be activated only on restricted areas of environmental emission control due to maintenance costs.
W referacie przedstawiono problemy spełnienia wymagań Międzynarodowej Organizacji Morskiej (IMO) odnośnie wymagań ograniczenia emisji toksycznych składników spalin z silników okrętowych. Propozycja użycia metod selektywnej katalitycznej redukcji (SCR) jest bardzo interesująca, ale prowadzi do wielu problemów w eksploatacji z powodu mechanizmów, które degradują systemy SCR. Niektóre z nich zaprezentowano w referacie. Degradacja systemów SCR powoduje pogorszenie parametrów ich pracy oraz spadek zdolności do zmniejszania emisji szkodliwych substancji w spalinach. Certyfikat EIAPP może nie potwierdzać rzeczywistych osiągów systemów SCR. Wymagać to będzie okresowych przeglądów potwierdzających spełnianie wymagań. Z powodu dużych kosztów eksploatacji systemów SCR będą one wykorzystywane jedynie na obszarach, na których zachodzi konieczność ich użycia, natomiast poza tymi obszarami będą one wyłączane. Pracować będą na systemach omijających systemy SCR.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2011, 28 (100) z. 1; 27-33
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A conceptual design and numerical analysis of the mixerless urea-SCR system
Autorzy:
Kaźmierski, Bartosz
Górka, Krzysztof
Kapusta, Łukasz Jan
Powiązania:
https://bibliotekanauki.pl/articles/2097591.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
NOx
SCR
selective catalytic reduction
wall film
CFD
selektywna redukcja katalityczna
Opis:
In the present study, an innovative design of a urea-selective catalytic reduction (SCR) system without conventional mixing elements was developed. The aim was to obtain a high degree of urea decomposition, and uniform ammonia distribution at the inlet to the catalyst, while minimising the liquid film deposition and keeping the compact design. The concept of the design was based on creating high turbulence and elongating the flow paths of the droplets. The design was verified through a series of numerical simulations based on the Reynolds-averaged Navier-Stokes (RANS) approach and a discrete droplet model (DDM) spray representation. The analysis included various operating conditions as well as subcooled and superheated sprays. A uniform ammonia distribution was achieved regardless of the operating points and spray properties. Additionally, in the case of a flash-boiling injection, a further reduction of the wall film was observed.
Źródło:
Combustion Engines; 2021, 60, 4; 12--20
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combination of LNT and SCR for NOx reduction in passenger car applications
Autorzy:
Maunula, T.
Powiązania:
https://bibliotekanauki.pl/articles/134216.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
NOx
Selective Catalytic Reduction
SCR
LNT
catalysts
diesel
selektywna redukcja katalityczna
katalizator
Opis:
The removal of NOx and particulate emissions in light-duty diesel vehicles will require the use of aftertreatment methods like Diesel Particulate Filters (DPF) and Selective Catalytic Reduction (SCR) with urea and Lean NOx Trap (LNT) (Euro 6 and beyond). A new concept is the combination of LNT + SCR, which enables on-board synthesis of ammonia (NH3), which reacts with NOx on the SCR catalyst. The main application for this kind system will be lighter passenger cars, where LNTs may be used instead of full urea-SCR system. That particular combinatory system was investigated by developing platinum (Pt) and rhodium (Rh) containing LNTs and SCR catalysts in this study. In the use conditions, the maximum temperature may reach temperatures up to 800°C and NOx reduction reactions should proceed without NO2 assistance in the SCR position after LNT and DPF. PtRh/LNT with the total loadings of 85 g/cft (2.8 g/L) and higher resulted in a high NOx efficiency above 80–90% with a broad operation window in the laboratory simulations. In the experimental conditions, a higher NH3 concentration after LNT was essential to simulate well the operation of SCR catalysts. The developed Cu-SCR catalyst showed a high hydrothermal durability up to the ageing temperature of 800°C and a wide operation window without the NO2 assistance (NO only in feed). Fe-SCR and V-SCR catalysts were more dependent on NO2. A studied concept had an air injection after LNT to keep SCR condition always in lean side, where the SCR reaction was promoted by oxygen resulting in high reduction selectivity to nitrogen (N2) without NH3 emissions. The simulations in reaction conditions and system design resulted in the proposals for the optimal design and main reaction mechanism in DOC + DPF + LNT + SCR systems.
Źródło:
Combustion Engines; 2014, 53, 2; 60-67
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Higher order fuzzy logic in controlling selective catalytic reduction systems
Autorzy:
Niewiadomski, A.
Kacprowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/201190.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Selective Catalytic Reduction
SCR
air pollution
nitrogen oxides
adjustable air filter
ammonia valve
interval-valued fuzzy logic system
fuzzy controlling of air filter adjustments
type-2 fuzzy logic system
fuzzy implications
selektywna redukcja katalityczna SCR
zanieczyszczenia powietrza
tlenki azotu
regulowane filtry powietrza
zawór amoniaku
rozmyte kontrolowanie zmian filtra powietrza
typ-2 systemu logiki rozmytej
implikacja rozmyta
Opis:
This paper presents research on applications of fuzzy logic and higher-order fuzzy logic systems to control filters reducing air pollution [1]. The filters use Selective Catalytic Reduction (SCR) method and, as for now, this process is controlled manually by a human expert. The goal of the research is to control an SCR system responsible for emission of nitrogen oxide (NO) and nitrogen dioxide (NO2) to the air, using SCR with ammonia (NH3). There are two higher-order fuzzy logic systems presented, applying interval-valued fuzzy sets and type-2 fuzzy sets, respectively. Fuzzy sets and higher order fuzzy sets describe linguistically levels of nitrogen oxides as the input, and settings of ammonia valve in the air filter as the output. The obtained results are consistent with data provided by experts. Besides, we show that the type-2 fuzzy logic controllers allows us to obtain results much closer to desired parameters of the ammonia valve, than traditional FLS.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 4; 743-750
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potentials for NOx and CO2 reduction of combined NSC + passive SCR system in Diesel passenger car application
Autorzy:
Wittka, T.
Holderbaum, B.
Powiązania:
https://bibliotekanauki.pl/articles/133953.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
exhaust aftertreatment
NSC
Selective Catalytic Reduction
SCR
fuel reformer
oczyszczanie spalin
selektywna redukcja katalityczna
Opis:
The stringent pollutant and CO2 emission limitation in upcoming legislation norms for Diesel passenger car applications force the introduction of exhaust aftertreatment systems with maximum purification and energetic efficiency. The state-off-the-art technologies for NOx reduction, NOx storage and reduction catalyst (NSC) and selective catalytic reduction catalyst (SCR), show challenges for robust performance under strongly extended emission relevant operation conditions from cold start to high engine load and speed. One technical solution is the combination of NSC and passive SCR. This paper presents the experimental results obtained in the EUproject “Powerful”. On engine test bench and demonstrator vehicle, an exhaust aftertreatment system combining NSC, passive SCR and fuel reformer technology was developed and experimentally investigated steady-state and on road. The engine independent NSC operation offers potentials for lowered fuel consumption penalty by avoiding engine rich operation. The intrinsic NH3 formation during the NSC regeneration is used for additional NOx conversion on the passive SCR and reduces NOx and CO2 emission.
Źródło:
Combustion Engines; 2014, 53, 2; 68-76
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical evaluation of urea-mixing devices for close-coupled selective catalytic reduction systems
Autorzy:
Kaźmierski, Bartosz Grzegorz
Kapusta, Łukasz Jan
Powiązania:
https://bibliotekanauki.pl/articles/24202462.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
urea water solution
urea mixer
selective catalytic reduction
SCR
roztwór mocznika
mieszalnik mocznika
selektywna redukcja katalityczna
Opis:
The following research presents a numerical evaluation of existing and conceptual urea-mixing devices used in close-coupled (to the engine) selective catalytic reduction (SCR) systems. The analysis was aimed at the assessment of urea-mixing devices that could considerably enhance the reduction of nitrogen oxides from the diesel-engine combustion process under a wide range of operating conditions, including cold starts. The analysis showed that replacing blade-equipped static mixers with perforated stationary mixing devices may provide a more uniform spatial distribution of ammonia at the inlet to the SCR catalyst and reduce pressure drops generated by mixing devices. Moreover, the conceptual mixing devices, based on combinations of the blade and perforated mixers to develop intensive turbulence, enabled the increase of the mixing length leading to effective decomposition of the urea-water solution (UWS), and provided uniform spatial distribution of ammonia, even for the small-sized mixing systems. However, the intensive mixing was often associated with a significant rise in the pressure drop.
Źródło:
Combustion Engines; 2023, 62, 2; 84--93
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of retrofit devices for the Horizon 2020 Cleanest Engine and Vehicle Retrofit Prizes
Autorzy:
Giechaskiel, Barouch
Suarez-Bertoa, Ricardo
Melas, Anastasios
Selleri, Tommaso
Maggiore, Maurizio
Powiązania:
https://bibliotekanauki.pl/articles/2097660.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
retrofit
fuel supply innovation
selective catalytic reduction
SCR
Horizon 2020 prizes
zasilanie paliwem
selektywna redukcja katalityczna
Horyzont 2020
Opis:
The Horizon 2020 prizes aimed at the development of retrofit and engines that would reduce pollution. The Retrofit prize had a winner, while the Engine prize not. In this paper we present the innovations that were tested at the Joint Research Centre (JRC) of the European Commission, and not awarded. One was a “condensation” aftertreatment device, two were devices inserted in the fuel supply system, and one a selective catalytic reduction (SCR) for NOx system. The testing of the “condensation” aftertreatment device showed that it could not with-stand the high exhaust gas temperatures. The results of the two fuel systems showed that they could not control efficiently the NOx emissions. The reductions of the pollutants were negligble for the levels that the prizes were aiming. The SCR system did not achieve any significant reduction of NOx, probably due to a malfunction of the device.
Źródło:
Combustion Engines; 2022, 61, 3; 7--34
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ammonia CI engine aftertreatment systems design and flow simulation
Autorzy:
Kuta, Kacper
Nadimi, Ebrahim
Przybyła, Grzegorz
Żmudka, Zbigniew
Adamczyk, Wojciech
Powiązania:
https://bibliotekanauki.pl/articles/2097643.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
ammonia
selective catalytic reduction
SCR
compression ignition engine
test rig
emissions
amoniak
selektywna redukcja katalityczna
silnik o zapłonie samoczynnym
stanowisko badawcze
emisje
Opis:
Investigation of exhaust emissions and ammonia flow behavior in the exhaust system incorporating with Selective Catalytic Reduction (SCR) unit is discussed. An aftertreatment system is designed to work without additional urea injection. This study is focused on obtaining optimal parameters for catalysis. Its effectiveness is considered as a function of basic parameters of exhaust gases mixture and SCR material characteristics. A 3D geometry of SCR with porous volume has been simulated using Ansys Fluent. Moreover, a 1D model of ammonia dual-fuel CI engine has been obtained. Results were focused on obtaining local temperature, velocity, and exhaust gases composition to predict optimal probes placement, pipes insulation parameters, and characteristic dimensions.
Źródło:
Combustion Engines; 2022, 61, 3; 3--10
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the ammonia concentration in the exhaust gas of the self-ignition engines
Badania stężeń amoniaku w spalinach silników z zapłonem samoczynnym
Autorzy:
Gis, W.
Żółtowski, A.
Grzelak, P.
Powiązania:
https://bibliotekanauki.pl/articles/134110.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
ammonia
Selective Catalytic Reduction
SCR
Laser Diode Spectrometer
LDS
Fourier Transform Infrared Analyzer
FTIR
amoniak
selektywna redukcja katalityczna
spektometr laserowo-diodowy
analizator podczerwieni z transformacją Fouriera
Opis:
In the article there was reviewed the principle of operation of the SCR type catalitic reactors and explained the reason, why ammonia appears in the exhaust gas. The principles of analyzers to measure the concentrations of ammonia in the exhaust gases was reviewed. There were examined changes in EU regulations on the emissions of vehicles engines in comparison to UNECE Regulation No. 49, series 05 of amendments.
W artykule przedstawiono zasadę działania reaktorów katalitycznych typu SCR oraz wyjaśniono przyczynę, dla której w spalinach pojawia się amoniak. Dokonano przeglądu zasady działania analizatorów do pomiarów stężeń amoniaku w spalinach. Przeanalizowane zostały zmiany wprowadzone w rozporządzeniach UE dotyczących emisji zanieczyszczeń z układów wylotowych silników pojazdów w porównaniu z Regulaminem EKG ONZ nr 49, seria 05 poprawek.
Źródło:
Combustion Engines; 2013, 52, 3; 575-580
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of the heat balance results of the selected Tier III-compliant gas-fuelled two-stroke main engines
Autorzy:
Korlak, Kamil
Powiązania:
https://bibliotekanauki.pl/articles/24202453.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
heat balance
two-stroke engine
LNG
liquified natural gas
SCR
selective catalytic reduction
EGR
exhaust gas recirculation
bilans cieplny
silnik dwusuwowy
skroplony gaz ziemny
selektywna redukcja katalityczna
recyrkulacja spalin
Opis:
Two-stroke engines are distinguished by the highest overall efficiency among all main engines. This is not only due to the low speed, and large piston stroke, but also to the high combustion temperature, which results in an increase in nitrogen oxides (NOx) emission. Technical solutions applied to bring main engines into compliance with current NOx emission standards set by the Tier III limits include the use of SCR and EGR systems, the implementation of the Otto cycle, and the application of liquified natural gas (LNG) as the low-emission fuel. Impact of the available Tier III-compliant technologies on the heat balance results is analysed using the example of the currently most popular dual-fuel main engines, i.e. WinGD X92DF and MAN G95ME-C10.5-GI. The possibilities of waste heat recovery in the electricity generation process and thereby improving the ship energy efficiency are discussed.
Źródło:
Combustion Engines; 2023, 62, 2; 24--28
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

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