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1

Injection system assessment to optimize performance and emissions of a non - road heavy duty diesel engine : experiments and CFD modelling

Auriemma M., Iannuzzi S.

Journal of KONES

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2012

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Vol. 19, No. 3

19-30

EN

The advancing emissions requirements and the customer demand for increased performance and fuel efficiency are forcing the diesel engine technology to keep improving. In particular, the large diesel engines are undergoing to a significant restriction in emission standards. Reaching the new limits requires innovative solutions, improved calibration and controls of the engine combustion technology, as well as the optimization of the injection system that has experienced the most fundamental development over the last decade. The objective of the paper is to present preliminary results of an investigation for the development of an efficient combustion system for marine diesel engines. The effect of different engine parameters on performance and engine out emissions were evaluated. Specifically, different nozzle geometries, injection pressure, injection timings were taken into account. The investigation was carried out both experimentally and numerically. Three different nozzles geometries for three different values of the start of injection were tested. The in-cylinder pressure, rate of heat release, NOx and soot were evaluated for a high load engine condition. The experimental activity was carried out on a large displacement single cylinder direct injection diesel engine equipped with a high-pressure common rail injection system able to manage multiple injections. The engine test bench was equipped with an external air supercharger able to set high air boost levels. The system controls the intake air temperature by means of a heater exchanger. The numerical investigation was carried out using the commercial CFD STAR-CD code in a three-dimensional domain including the cylinder head and piston bowl. Combustion behaviour was simulated using the 3 Zones Extended Coherent Flame Model (ECFM3Z).

2

The Wärtsilä 34DF engine for wide fuel flexibility

Sutkowski M., Latvasalo T.

Silniki Spalinowe

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2009

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R. 48, SC2

42--48

EN

The Wärtsilä 34DF engine is a stationary turbocharged “Dual-Fuel” engine which can operate on gas and oil fuel. The ported low-pressure gas injection is applied in this engine and the ignition of gas-air mixture is forced by pilot oil injection. The engine can also run on oil fuel only if necessary. This feature provides very wide fuel flexibility and operation reliability. The engine development and the most important components of the Wärtsilä 34DF engine are presented. The working principles, operation modes and the procedure of switching between fuels are explained. The Wärtsilä 34DF engine performance and emission levels are described in the paper as well. The paper includes also specification for gas and oil fuels that can be used for the engine operation. The paper is concluded with some typical application and the experience from running the engines in challenging conditions.

PL

Silnik Wärtsilä 34DF jest stacjonarnym turbodoładowanym silnikiem dwu-paliwowym, który może spalać paliwa gazowe oraz olejowe. Silnik jest wyposażony w niskociśnieniowy kolektorowy wtrysk gazu, a zapłon mieszanki gazowo-powietrznej jest wymuszony wtryskiem pilotującej dawki paliwa olejowego. Silnik może być zasilany tylko paliwem olejowym, jeśli zachodzi taka konieczność. To rozwiązanie stwarza bardzo szerokie możliwości co do stosowania wszelkiego rodzaju paliw zapewniając dużą pewność działania silnika. Prace rozwojowe oraz główne podzespoły silnika Wärtsilä 34DF zostały zaprezentowane w tym artykule. Również zasada działania, podstawowe tryby pracy oraz procedury przełączania miedzy różnymi paliwami zostały omówione. Ponadto przedstawione są osiągi silnika oraz poziom emisji zanieczyszczeń. Artykuł zawiera również charakterystykę paliw gazowych oraz olejowych dopuszczonych do stosowania w tym silniku. W podsumowaniu artykułu są przedstawione przykładowe zastosowania silnika oraz doświadczenie z pracy silników w trudnych i wymagających warunkach.

3

The Wärtsilä 32GD engine for heavy gases

Järf Ch., Sutkowski M.

Silniki Spalinowe

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2009

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R. 48, nr 2

3-11

EN

The Wärtsilä 32GD engine is a stationary turbocharged "Gas-Diesel" engine which can operate on gas and oil fuel.The direct high-pressure gas injection is applied in this engine. The sophisticated control system of the engine allows operation on gas and oil fuel with very wide range of gas/oil fuel ratio which provides a unique flexibility of fuel usage.The Wärtsilä 32GD technology offers possibility to use good quality gas or heavier gases i.e. with high content of heavier hydrocarbons. The Wärtsilä 32GD engine development and the most important components of the Wärtsilä 32GD engine are presented. The working principles, operation mode, the engine performance and emission levels are described in the paper as well. The paper includes also specification for gas and oil fuels that can be used for the engine operation. The paper is concluded with some typical applications, reference installation and experience from running the engines on challenging fuels.

PL

Silnik Wärtsilä 32GD jest stacjonarnym turbodoładowanym gazowym silnikiem Diesla. W tym silniku zastosowano bezpośredni wysokociśnieniowy wtrysk gazu. Zaawansowany układ kontroli silnika pozwala na stosowanie jednocześnie paliwa gazowego i olejowego w bardzo szerokim zakresie zmian proporcji miedzy tymi paliwami, co pozwala na niespotykaną swobodę doboru stosowanych paliw. Technologia silnika Wärtsilä 32GD pozwala na stosowanie zarówno lekkich gazów, takich jak gaz ziemny, jak i gazów z dużą zawartością ciężkich węglowodorów. W niniejszym artykule przedstawiono zasadę działania, możliwe tryby pracy, osiągi silnika oraz poziom emisji zanieczyszczeń. Artykuł zawiera również specyfikacje możliwych do zastosowania paliw gazowych i olejowych. W podsumowaniu przedstawiono typowe zastosowania silnika Wärtsilä 32GD oraz doświadczenia z pracy silników z zastosowaniem wymagających paliw.

4

Influences of Alternative Fuels GTL, RME and ROR on Combustion and Emissions of a Modern HD-Diesel Engine

Czerwinski J., Zimmerli Y., Neubert T., Heitzer A., Kasper M.

Silniki Spalinowe

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2007

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R. 46, nr SC3

180-200

EN

Due to the limited energy resources as well as due to increasing CD2-emissions the importance of alterative- and biogene fuels is continuously increasing. Investigations of the engine operation were performed on a latest technology Liebherr engine for construction machines. It was operated using crude rapseed oil (RDR)'), rapeseed oil methyl ester (RME), synthetic Gas-To-Liquid fuel (GTL) and diesel (as reference fuel). The combustion diagnostics, the performance of the injection system as well as the pollutant emissions, including unlimited nanoparticles were assessed. The most important findings ean be summarized as joilows : Fuel injection - Both, RME and RDR shortened the injection delay which was due to a quicker increase of injection pressure and a faster needle lift, - the highest maximum injection pressure was observed with RDR (1610 bar), followed by RME (1580 bar), Diesel (1450 bar) and GTL (1410 bar), - As compared to diesel, GTL exhibited no significant differences of hydraulic behavior. Combustion - Usually, GTL caused a shorter ignition delay, but it burned slower, so that 50% of heat release took place at the same CA-position, as for Diesel. in addition, GTL provoked a lower rate of pressure raise and reduced the maximum combustion pressure. These effects were particularly pronounces at lower and medium loads. - At higher engine load RDR and RME started to bum earlier and at a higher rate, than Diesel and GTL. Therefore, 50% of the heat release followed with ROR and RME 1-2 CA earlier which had consequences for the NOx emissions. Limited emissions and energy consumption GTL lowered generally ail emission components - as compared to standard Diesel fuel. In addition, the energy consumption with GTL was equal or slightly lower. RME lowered CO and HC emissions and increased NOx emissions at ail operating points. It lowered PM at higher engine loads and increased PM at lower engine loads. RME had no effect on specific energy consumption. ROR lowered CO, HC and PM at ail operating points by at least 50% or more. In the high-load-operation RDR reduced the specific energy consumption (approx. 2%) and increased NOx (up to approx.5%). At low-load-operating points (1500 rpm/10%) ROR did not affect CO and NOx, but increased PM emissions and energy consumption. Nanoparticle emissions - GTL and diesel nanoparticle emissions were identical, - Both RME and RDR moved the PSD spectra to smaller sizes and increased the nuclei mode due to spontaneous condensate formation, - Both RME and RDR caused lower particle emissions at high load and higher emissions at low load, The use of ROR resulted in a particularly high portion of condensates (SDF) at low load and idling.