Wyniki wyszukiwania - Biblioteka Nauki

1

The diagnosis of EGR system's failuers depended on detection and measure of vibroacustic vibrations

100%

Kaźmierczak A. , Miksiewicz K. , Wróbel R.

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tom nr 4(56)

27-35

EN

The authors presents a new in - vitro way of diagnosis in automotive vehicle which depend on detection and measure of vibroacustic vibrations of the diesel engine. It seems that the Exhaust Gas Recirculation circuit that does not work properly shouldn't have an influence on vibrations generated by an engine. However, authors indicate that this statement is wrong. EGR system has an influence on engine's vibration, what was described in the article. On that way, detection of vibrations must be accomplished with high quality diagnostic systems. Therefore, vibrometric laser scanner Polytec had been used. To achieve full diagnostic results multidimensional vibration's function has been researched, where the torque moment has been used as an extra parameter. Measured vibrations were subjected to digital signal processing like windowing, fast Fourier transform, filtration by finite impulse response which also undergone to windowing . The results of measure and processing perform in form of 3D plots, which indulge in speed estimate of the usefulness of presented method. Moreover authors presents principle of working EGRs' systems of different generations, its evolution and history. A EGR is a popular system of recirculation of the automotive vehicle emission. The principle of working depends on the forcing in the part of outlet gas to the combustion chamber. Majority of the users of automotive vehicles with EGR systems claim that system has negative effect on the performance of the car. Nonetheless that opinion is subjective, because the generally available research on the subject doesn't exist. However, EGR system, as the most of automotive vehicle is being subjected to physic's rules - it uses up. The polluted flowing valve of circuit has an influence on stability of engine's work, and what follows on a performance of a car.

PL

Autorzy prezentują nową metodę diagnostyczną (in-vitro), wykorzystywaną w diagnostyce pojazdów samochodowych, polegającą na detekcji i pomiarze wartości drgań o charakterze wibroakustycznym. Wydaje się, że niesprawność układu recyrkulacji spalin nie powinna mieć wpływu na drgania, generowane przez silnik spalinowy. Autorzy dowodzą, że twierdzenie taki jest błędne. W tym wypadku koniecznym jest wysokiej jakości układ diagnostyczny. Dlatego użyto głowicę laserową firmy Polytec. Na podstawie badań otrzymano wielowymiarową funkcję wibroakustyczną, w której dodatkową zmienną jest wartość momentu obrotowego. Zmierzone drgania zostały poddane operacją cyfrowego przetwarzania sygnałów, takich jak okienkowanie, FFT, filtracji z użyciem filtrów o skończonej odpowiedzi impulsowej, które zostały poddane dodatkowo operacją okienkowania. Rezultaty pomiarów i przetwarzania zostały zaprezentowane w postaci obrazowania 3D, które w wypadku tej metody diagnostycznej wydają się najlepsze. Ponadto autorzy prezentują rozwój układów EGR różnych generacji. Zasada pracy tego układu polega na wtłoczeniu do komory spalania części gazów wylotowych. Duża część użytkowników tego systemu twierdzi, że jego działanie ma negatywny wpływ na osiągi pojazdu. Nie można jednak stwierdzić czy twierdzenie to jest właściwe gdyż dotychczas brakuje badań prowadzonych w tym kierunku. Pomimo tego pewne jest, że zanieczyszczony zawór układu EGR na pewno będzie miał wpływ na osiągi pojazdu.

2

Droga do Euro-4: EGR czy SCR?

94%

Więcławski D.

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tom R. 7, nr 6

28-31

PL

W artykule przedstawiono ograniczenia jakie nakładają normy czystości spalin Euro-4 na producentów silników oraz jakie zmiany będą wymagane w budowie układów napędowych.

3

Potential application of CO2 for enhanced condensate recovery combined with geological storage in the depleted gas-condensate reservoirs

94%

Burachok O. , Nistor M. L. , Sosio G. , Kondrat O. , Matkivskyi S.

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tom nr 2 (29)

106--113

EN

CO2 emissions are considered to be the main contributor to global warming and climate change. One of the ways reducing the emissions to atmosphere is a proper capture and further geological storage of the carbon dioxide. In the oil industry, CO2 is used as one of the injection agents to displace oil and enhance its recovery. Due to the low multi-contact miscibility pressure between CO2 and hydrocarbons, fully miscible condition is quickly reached, leading to efficient displacement and high recovery factors. The utilization of the depleted gas fields for CO2 storage, however, is considered as the option that is more expensive compared to oil field, since the enhanced recovery of gas with CO2 is not effective. For this reason, our study considers the potential use of CO2 EOR in depleted gas-condensate fields. This potential is evaluated by performing numerical simulations for the typical-size gascondensate reservoirs with no active aquifer, in order to estimate both the storage efficiency and the additional oil recovery from condensed C5+ hydrocarbon fractions, that otherwise will be never recovered and lost in the reservoir. Obtained results indicate significant potential for CO2 storage and additional condensate recovery from the typical gas-condensate field of Eastern Ukraine.

4

Application and comparison of soy based biodiesel fuel to ultra low sulfur diesel fuel in a HPCR diesel engine - part I: engine performance parameters

94%

Mathur V. K. , Moscherosch B. W. , Polonowski C. J. , Naber J. D.

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tom Vol. 15, No. 3

327-334

EN

In the US transportation sector uses two-thirds of the country's total oil consumption. In order to minimize the consumption in this sector there is a need to investigate alternate sources of energy. Biodiesel is a possible alternative to conventional diesel. Biodiesel has many characteristics similar to petroleum based diesel and can be blended with petroleum. However biodiesel's differences in fuel properties including viscosity, bulk modulus, density, and energy content can have significant impacts on engine performance parameters like BSFC and thermal efficiency. As the availability of biodiesel fuel increases, the need for engines capable of running on various mixtures of biodiesel fuel will be required. Similar to flex-fuel ethanol vehicles, control systems for the diesel engine and aftertreatment systems will need to detect and compensate for the fuel type. In this work, a soy based B100 biodiesel fuel and an ultra low sulfur diesel fuel were tested in a high-speed direct-injection high pressure common rail four-cylinder 1.9 L diesel engine. An internally developed engine control strategy allowed real-time calibration and testing of independent control parameters including start of injection, injection duration, injection pressure, and exhaust gas recirculation (EGR) level. Both the fuels were studied under varied injection timing (0°BTDC to 12°BTDC with increments of 3°) and EGR percentages of 0 and 10%. Analysis was performed to determine the Torque, BSFC and Brake thermal efficiency.

5

Wspomaganie wydobycia ropy naftowej i gazu ziemnego z polskich złóż z wykorzystaniem CO2 i jego równoczesną sekwestracją

84%

Lubaś J. , Szott W. , Wójcicki A.

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tom nr 465

45--56

PL

Publikację przygotowano na podstawie wyników badań uzyskanych przez Konsorcjum, składające się z Instytutu Nafty i Gazu oraz Państwowego Instytutu Geologicznego – Państwowego Instytutu Badawczego, w ramach projektu realizowanego na zamówienie Ministerstwa Środowiska pt. ,,Program wspomagania wydobycia ropy naftowej i gazu ziemnego z krajowych złóż węglowodorów przy zastosowaniu podziemnego zatłaczania CO[sub]2[/sub]”. Wykonano badania symulacyjne efektywności zastosowania w wybranych złożach ropy i gazu procesów CO[sub]2[/sub]–EOR, EGR z równoczesną sekwestracją CO[sub]2[/sub]. W pierwszej części na przykładzie wytypowanych 10 złóż oceniono możliwości zwiększenia krajowych zasobów wydobywalnych ropy naftowej i gazu ziemnego, przy wykorzystaniu omawianych metod. Następnie określono potencjał składowania CO[sub]2[/sub] w wytypowanych złożach węglowodorów z zastosowaniem metod CO[sub]2[/sub]–EOR, EGR Na zakończenie przeprowadzono wstępną analizę opłacalności ekonomicznej symulowanych metod.

EN

The paper was prepared based on the research results obtained by the consortium of Oil and Gas Institute and Polish Geological Institute – National Research Institute within the project ordered by the Ministry of the Environment and entitled: “Program of Enhanced Oil and Gas Recovery from Domestic Hydrocarbon Reservoirs by the Application of Underground CO2 Injection”. The effectiveness of the CO[sub]2[/sub]–EOR, EGR methods with simultaneous CO[sub]2[/sub] sequestration was studied usingreservoir simulations for selected oil and gas reservoirs in Poland. The first part of the paper includes an evaluation of the potential of the above methods to increase recoverable oil or gas reserves in 10 selected reservoirs. The second part of the paper includes an assessment of the CO[sub]2[/sub] storage potential of the same reservoirs using the studied methods. The paper concludes with the introductory economic analysis for the profitability of the simulated methods.

6

Vibroacoustic diagnosis of EGR system

84%

Kazmierczak A. , Wróbel R.

Silniki Spalinowe

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2008

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tom R. 47, nr 3

40-51

EN

The Exhaust Gas Recirculation is a popular system of recirculation of the automotive vehicle emission. The principle of working depends on the forcing in the part of outlet gas to the combustion chamber. The polluted flowing valve of circuit has an influence on stability of engine's work. The authors presents a new way of diagnosis in automotive vehicle which depend on detection and measure of vibroacustic vibrations that were subjected to digital signal processing. It seems that EGR circuit that does not work properly shouldn't have an influence on vibrations generated by an engine. However, authors indicate that this statement is wrong.

PL

System recyrkulacji spalin gazów wylotowych jest popularnym systemem wykorzystywanym do ograniczania emisyjności pojazdów samochodowych. Zasada działania systemu jest oparta na wtłoczeniu do komory spalania części gazów wylotowych. Zanieczyszczony zawór dolotowy systemu ma wpływ na stabilną pracę silnika. W niniejszym artykule autorzy prezentują nową metodykę diagnostyczną opartą na pomiarze drgań, poddanych operacjom cyfrowego przetwarzania sygnału. Wydaje się, że nieprawidłowo działający układ EGR nie powinien mieć wpływu na drgania generowane przez silnik. Autorzy wykazują, że takie stwierdzenie jest błędne.

7

Effect of EGR on nanoprticles at Common-rail diesel engines exhaust

84%

Merola S. S. , Tornatore C. , Vaglieco B. M.

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tom R. 46, nr SC3

206-217

EN

In the last years, diesel emission control strategies based on engine design and after-treatment devices, have been very successful in the reduction of the total particulate mass and gaseous emissions. Nevertheless they have been significantly less effective in reducing the total number of particles. Thus, when EURO 5 will be introduced, it will be difficult to meet the emission standards with the present technologies. Nowadays diesel engines are equipped with the Exhaust Gas Recirculation (EGR) system that allows the reduction of thermal-Nitrogen Oxides but it could also influence particles emissions. For this reason, the aim of the present work is to evaluate the effect of EGR on the balance between the primary particles and the aggregates at the exhaust of diesel engines. The idea is to find out a relation between EGR percentage and the size of the emitted particles for every speed and load. Two different methodologies for detection, sizing and counting nanoparticles were used. Electrical Low Pressure Impactor (ELPI) measured the particle size distributions in the range 7 nm-10 μm, without distinction between primary particles and aggregates. Laser Induced Incandescence (LII) allowed to determine soot primary particles diameter. ELPI measurements pointed out the increasing of number concentration and size of particles with the EGR. The size distributions showed a maximum in the range of 54-91nm with negligible number of particles larger than 300 nm. For alt the conditions, an increase of number concentration of particles bigger than 54 nm and a reduction of smaller ones was measured. This was due to the agglomeration effect caused by the reintroduction of particles contained in the exhaust gases into the cylinder during the EGR. LII measurements showed that at fixed engine speed and for alt EGR values, the diameters of primary particles increased with engine load. Moreover smaller primary particles were formed at higher speed. With respect to EGR variation, for every condition the primary particles diameters increased due to the partial oxidation of soot recirculated in the combustion chamber ad the successive superficial growth. Taking into account the proposed results, for each engine operating condition, the best EGR value could be chosen taking into account the size distribution of the produced particles and not only the NOx-soot trade-off.

8

Comparative analysis of the heat balance results of the selected Tier III-compliant gas-fuelled two-stroke main engines

67%

Korlak K.

Combustion Engines

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2023

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tom R. 62, nr 2

24--28

EN

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.

9

Examination of the influence of multi-injection strategy on thermodynamic indexes of engine cycle and on the emission of toxic compounds

59%

Czajka J. , Wisłocki K. , Pielecha I. , Borowski P.

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tom R. 53, nr 2

45--59

EN

The main target of this work was to investigate on the 1-cyl. research engine concerning practical realization possibilities of cold-flame-combustion when operating with high and very high Exhaust Gas Recirculation (EGR) rates. After determining of possibilities of lowering NOx and Soot emissions for EGR rates ca. 40-60% some further investigation on optimization of SOIand CoC parameters were performed. Additionally, some preliminary investigations of the optimization of combustion parameters when applying various strategies of multi-injection have been conducted and analyzed.

PL

Głównym celem badań było uzyskanie efektu spalania niskotemperaturowego skutkującego zmniejszeniem emisji NOx wraz z jednoczesnym zmniejszeniem emisji sadzy (cząstek stałych) dzięki zastosowaniu dużego stopnia recyrkulowanych spalin. Po uzyskaniu możliwości obniżenia emisji NOx i sadzy przy zastosowaniu recyrkulacji spalin o udziale 40-60%, prowadzono dalsze badania nad optymalizacją parametrów SOI i CoC. Dodatkowo, prowadzono wybrane wstępne badania optymalizacyjne parametrów procesu spalania przy stosowaniu różnych strategii wtrysku wieloczęściowego.

10

Numerical investigation on diesel combustion and emissions with a standard combustion model and detailed chemistry

48%

Pyszczek R. , Schmalhorst C. , Teodorczyk A.

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2015

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tom R. 54, nr 3

19--33

EN

The aim of this study was to determine possibilities of the soot and NOx emissions reduction from an existing heavy-duty compression-ignition (CI) engine based only on in-cylinder techniques. To that end numerical simulations of such processes as a multiphase fuel flow through injector nozzles, a liquid fuel jet breakup and evaporation, combustion and emissions formation were performed in AVL Fire 3D CFD software. The combustion process was calculated with the ECFM-3Z model and with the detailed n-heptane oxidation scheme that consisted of 76 species and 349 reactions. Both approaches of combustion modeling were validated against experimental data from the existing engine working under 75% and 100% loads. As for the reduction of the NOx emission an introduction of exhaust gas recirculation (EGR) was investigated. As for the soot concentration reduction such measures as an increased rail pressure, application of a post-injection and an increased injector nozzles conicity were investigated. Finally the ECFM-3Z model with emissions models, as well as the n-heptane mechanism predicted that it is possible to reach specified emissions limits with application of EGR, post-injection and increased nozzles conicity.

11

Gas turbines – technological development and potential use in CAES systems

48%

Jakowski D. , Dzida M.

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tom R. 55, nr 2

46--53

EN

This article briefly describes Compressed Air Energy Storage (CAES), focusing on the technological development of one of the key elements of such systems – the gas turbines. It presents the basic parameters and features of gas turbines, as well as turbine classes with example models. Main tendencies in the structural and technological development are discussed. Changes and trends on electric energy markets are becoming more and more dependent on sources with flexible operating characteristics, therefore, the advantages of gas turbines and the reasons for their development are listed as well.

PL

W artykule przedstawiono krótką charakterystykę magazynowania energii w sprężonym powietrzu (CAES), skupiając się na przeglądzie osiągnięć technologicznych jednego z podstawowych elementów tych układów – turbin gazowych. Opisano podstawowe parametry i cechy turbin gazowych, a następnie klasy turbin z przykładowymi modelami. Przedstawiono główne tendencje w rozwoju konstrukcyjnym i technologicznym. Zmiany i trendy na rynkach energii elektrycznej coraz bardziej zależą od źródeł o elastycznej charakterystyce pracy, dlatego zestawiono również zalety i powody rozwoju turbin gazowych.