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1

Effect of pilot charge size and biogas composition on the operating efficiency of a dual-fuel compression-ignition engine

Wierzbicki S., Śmieja M., Mikulski M., Piętak A.

Journal of KONES

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2014

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Vol. 21, No. 3

279--284

EN

Reduction of greenhouse gases emissions into the atmosphere, as well as increasing the share of renewables in the overall energy balance, forces the search for new, alternative energy sources. One of the fuels, which presents high potential for combustion engines are biomethane or biogas, with methane as the main flammable component. Biogas can be obtained from different products and using a variety of technologies which results in its wide availability and relatively easy manufacture. The largest sources of biogas can be animal farms or sewage treatment plants and waste dumps in which significant quantities of biogas are obtained as a result of naturally occurring processes. Biogas can also be obtained from processing of energy crops or waste processing in agricultural, food and meat processing plants. In this article, the possibility of using biogas as a fuel for CI engines has been examined. In such engine, combustion of biogas (methane) requires the use of dual fuel supply system, in which in addition to methane, liquid fuel is injected into the combustion chamber, in order to initiate the self-ignition of gaseous fuel. The paper presents exemplary results of the impact of the proportion of different fuels and biogas composition on the efficiency of the engine work cycle.

2

Some possibilities of dual fuelling supply diesel engines

Stelmasiak Z.

Journal of Polish CIMAC

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2013

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Vol. 8, no 2

79--90

EN

In the paper are presented conditions for gaseous fuelling of different engine types: stationary engines and traction engines to trucks and passenger cars. On the base of performed investigations, one made comparison of operational costs of dual fuel gaseous engines and an engines with spark ignition system. In the analysis one took into consideration operation of an engine on natural gas, the most expensive gas, and on the mine gas, so called cheap gas. In case of stationary engines, the analysis showed considerable benefits of the dual fuel system comparing with spark ignition system. One confirmed considerable savings in purchasing costs of the fuels, regardless of size of initial dose and price of the gas. Earnings in purchase of the fuels increase together with growth of price of the gas and reduction of initial dose. In traction engines one should use the CNG or LNG gas. During transitional period of introduction of the gas one should implement systems with full interchangeability of fuelling with gaseous fuel and liquid fuel, both in compression ignition and spark ignition engines. Used in trucks, the dual fuel system gives substantial savings in operational costs and improves conditions of engine operation comparing to systems with spark ignition. In turn, in case of passenger car engines, due to size of the engines and different operational conditions, systems with spark ignition and so called flexi-fuel systems should be used. Due to it, gaseous fuelling in passenger cars should be first implemented in the engines with spark ignition system.

3

Impact of engine control on the energetic inter change ability of diesel oil by gas in dual fuel GI engine

Stelmasiak Zdzisław

Journal of KONES

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2013

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Vol. 20, No. 4

425--434

EN

A compression ignition engine fuelled simultaneously with two fuels: a fuel with low cetane number used as the main fuel, and Diesel oil used to initiation of ignition, is assumed to be called as a dual fuel engine. This system is perfectly suited to adaptation to supply of CNG gas in majority of compression ignition engines. Such adaptations can concern both an older engine equipped with classic injection system, and modern engine with common rail system. In traction engines, interchangeability of liquid fuel by the gas belongs to important issues, what is a condition of profitability of the adaptation and operation of dual fuel engines. In the paper are presented test results of the 1CA90 engine with piston pump to injection of liquid fuel, and a system with mixer to supply of the gas; and the SB3.1 engine equipped with common rail system and injection of the gas in area of the inlet valve. On the base of performed tests one has shown variability of energetic fraction of the CNG gas in total energy supplied to the engine. The tests were performed in complete field of variability of engine parameters, i.e. rotational speed and engine load. Obtained results have shown that in spite of decreasing fraction of the gas at partial loads of medium size traction engines, substantial reduction of operational consumption of the Diesel oil is possible. Due to significant differences in price of the CNG gas and the Diesel oil, it gives considerable savings in operational costs of the engines. It should encourage users of the engines to adaptation of the fuelling to the CNG gas. In the paper is presented a proposal of control system to dual fuel traction engine, from maintaining its performance parameters point of view.

4

Sterowanie spalaniem w dwupaliwowym silniku ZS przez podział dawki inicjującej

Stelmasiak Z.

Silniki Spalinowe

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2011

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R. 50, nr 3

PL

W pracy przedstawiono wyniki badań dwupaliwowego silnika zasilanego gazem ziemnym sprężonym i olejem napędowym jako dawką inicjującą. Podstawowym celem badań było określenie możliwości aktywizacji spalania mieszaniny gaz-powietrze przez podział dawki inicjującej. Dawka pierwsza wtryskiwana z kątem wyprzedzenia zapłonu jak przy zasilaniu samym olejem napędowym miała za zadanie zainicjowanie procesu spalania. Druga dawka wtryskiwana ze zmiennym opóźnieniem, w założeniu już w czasie trwania procesu spalania, miała za zadanie podtrzymanie spalania mieszaniny gazowej. Sterowanie procesem spalania osiągano przez zmiany kąta opóźnienia wtrysku dawki dodatkowej. Podział dawki inicjujące powoduje obniżenie ciśnień maksymalnych spalania, szybkości przyrostu ciśnienia oraz istotne zmniejszenie szybkości wydzielania ciepła. W efekcie sterowanego spalania zaobserwowano wzrost sprawności ogólnej silnika oraz zmniejszenie stężenia NOx w spalinach. Równocześnie nieznacznemu pogorszeniu uległa emisja CO i TCH.

EN

The paper presents the results of dual fuel engine fuelled by compressed natural gas and diesel oil as the initial dosage. The primary objective of this study was to determine the possibility of activating the combustion gas-air mixtures by a division of initial dosage. First dose injected to the angle of ignition timing as with the diesel oil supply was required to initiate the combustion process. Second dose is injected with a variable delay, the assumption still during the combustion process, was charged with maintaining the combustion gas mixture. Controlling the combustion process is achieved by changing the angle of delay of an extra dose injection. Division of initiation dose lowers the maximum combustion pressure, rate of pressure increase and a significant reduction the heat release rate. As a result of controlled combustion showed an increase in thermal engine efficiency and reduce NOx emissions. At the same time slightly deteriorated, CO and TCH.

5

Possibility of improvement of some parameters of dual fuel CI engine by pilot dose division

Stelmasiak Z.

Journal of Polish CIMAC

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2011

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Vol. 6, no 1

181-190

EN

The paper present a test results of dual fuel engine run on natural gas and diesel oil injected as a pilot dose. Determination of possibilities of engine’s operational parameters improvement through division of the pilot dose was the main objective of the presented research. The first dose injected at ignition advance angle, the same as in case of operation on diesel oil only, has as its task to initiate process of combustion. The second dose, injected with changing delay when, as assumed, phase of combustion process is already in progress, has as its task to sustain combustion of gaseous mixture. Control of combustion process was attained through changes of injection delay angle of additional dose. Division of pilot dose effects in a considerable reduction of maximal heat release rate during combustion with simultaneous growth of average combustion rate of gas-air mixture. In result, it has been observed a growth of overall efficiency of the engine, reduction of NOx concentration in exhaust gases, and reduction of maximal combustion pressures. Simultaneously, emission of the CO and TCH was slightly worsened.

6

Attempt to compare basic combustion parameters of a dual-fuel compression ignition engine for various main fuels and their delivery modes

Luft S.

Czasopismo Techniczne. Mechanika

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2008

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R. 105, z. 7-M

25-38

EN

The paper presents results of investigation on a dual-fuel engine fuelled with various fuels (methanol, propane-butane mixture). In all cases, ignition of the main fuel was initiated by a diesel oil pilot dose injected into the combustion chamber. Engine power was controlled by changes of the main fuel charge (methanol or LPG). The paper presents comparison of engine performances, efficiency and variability of basic combustion parameters with reference to a standard engine fuelled with diesel oil only.

PL

W artykule przedstawiono wyniki badań dwupaliwowego silnika o zapłonie samoczynnym zasilanego różnymi paliwami (metanolem, propanem-butanem). W każdym przypadku zapłon paliwa głównego inicjowany był dawką oleju wtryskiwaną do komory spalania. Regulacja mocy silnika odbywała się poprzez zmianę wydatku paliwa w fazie gazowej (metanolu lub LPG). W artykule przedstawiono porównanie osiągów, sprawności oraz zmiany podstawowych parametrów procesu spalania w odniesieniu do silnika zasilanego standardowo tylko olejem napędowym.