Wyniki wyszukiwania - Biblioteka Nauki

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Experimental Investigation on Indicated Pressure and Heat Release for Direct Hydrogen Injection in a Dual Fuel Diesel Engine

100%

Siadkowska K. , Barański G. , Sochaczewski R. , Wendeker M.

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tom Vol. 16, no 3

54--66

EN

This paper presents the research results for a diesel and hydrogen fueled engine. The research object is a four-cylinder, four-stroke ADCR engine with a displacement of 2,636 cm3. In the experiments, glow plugs were replaced with compressed hydrogen injectors and a special adapter. Hydrogen was supplied directly into a combustion chamber using a test injector. A hydrogen dose in the tests was changed at selected test points and ranged from 0 to 160 dm3/min. The research were conducted at 1,500 rpm. A hydrogen injection start angle and maximum hydrogen dose were specified from the preliminary experiments. The following parameters were analyzed: indicated mean effective pressure, maximum pressure, crank angle of maximum cylinder pressure occurrence and heat release. The obtained results were statistically analyzed. The conducted analysis focused on determining whether there are significant differences between early and late injection and how these changes affect the measured parameters.

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Dual fuelling CI engine with methanol and diesel oil

88%

Stelmasiak Z.

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tom Vol. 20, No. 3

387--393

EN

Dual fuel compression ignition engine can be run on diverse fuels, both gaseous and liquid ones. Alternative fuels to the Diesel oil feature, as a rule, low cetane number and high temperature of self-ignition. Due to this, such fuels can not be ignited spontaneously and require ignition from small dose of the Diesel oil. In the dual fuel system, as the main fuel can be considered a liquid fuels, which can be supplied to the cylinder in form of vapours, or injected be to the suction manifold. Methyl and ethyl alcohols, or their esters, can be counted among future fuels. Such alcohols can be either the main fuels or small additions improving combustion of the Diesel oil. In the paper are presented test results of the SW 680 engine run on methanol and Diesel oil. Methanol was supplied to the suction manifold in form of methanol-air aerosol. Energetic fraction of the methanol amounted to 12-50%, depending on engine load. Performed tests have shown advantageous effect of the methanol on performance of the engine. One confirmed considerable growth of overall efficiency of the engine in area of higher loads (3-6%), reduction of smokiness of exhaust gases achieved as early as with small additives of the methanol (2-3 times), reduction of CO and CO2 emissions, reduction of exhaust gases temperature. Small addition of the methanol affects advantageously on combustion of the Diesel oil, shortening time if its combustion. Addition of the methanol enables maintaining effective power of the engine fuelled traditionally, and even its slight growth. Cost of adaptation to dual fuel supply with alcohol are low, and such type of fuelling can be easy implemented in already operated compression ignition engines.

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LES numerical study on n-hexane injection in a compression ignition engine

63%

Kercheva B. , Kapusta Ł. J. , Teodorczyk A.

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tom Vol. 34 nr 2

155--167

EN

The aim of the study was the comparison of different approaches to modeling the injection process in a heavy duty compression ignition engine. The conducted numerical investigation concerned n-hexane direct injection into the engine combustion chamber. Simulations were performed using AVL Fire software, a CFD (Computational Fluid Dynamics) code based on the control volume method. In order to achieve engine conditions, computational model was built basing on piston and cylinder geometry of a real engine and the mesh deformation was defined according to crank mechanism dimensions of the engine. In presented simulations for modeling dispersed phase the Lagrangian approach was used. For capturing the turbulent patterns present in the flow, the Large Eddy Simulation (LES) approach was used. Three different nozzle outflow conditions were compared. In the simplest case, constant flow rate was defined. In the second one, linear stage of increase and decrease of flow rate was defined, and in the third one – the most advanced – data collected during previously done in-injector cavitating flow simulations were used to define the flow parameters on the nozzle outlet. Calculated results for all cases were analyzed and compared. The focus was on the initial stage of the spray. The results show that the way of defining parameters at the outlet influences not only the initial stage of the spray but the whole process.

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Systemy dwupaliwowe silników wysokoprężnych lokomotyw spalinowych - Gazodiesel

63%

Dumenko P. , Babeł M.

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tom R. 26, nr 11-12

62--66

PL

Wdrożenie w silnikach Diesla lokomotyw spalinowych systemów dwupaliwowych – olej napędowy / gaz ziemny, prowadzi do obniżenia emisji substancji szkodliwych w spalinach oraz oszczędności w związku z konkurencyjnymi cenami gazu ziemnego. Przedstawiono opis zespołów i urządzeń systemu dwupaliwowego wdrożonego na lokomotywie spalinowej serii S200 wraz z rysunkami ich zabudowy w pojeżdzie. Omówiono zagadnienia dotyczące układu sterowania, prób i badań lokomotywy, certyfikacji, infrastruktury tankowania gazu. Zaprezentowano wyniki badań stacjonarnych i ruchowych lokomotywy oraz uzyskane efekty.

EN

With 70% of all locomotives still being powered by diesel and most of the locomotives being older than 30 years, the railway industry must urgently seek environmentally friendlier and economically more attractive alternatives to diesel fuel. Dual-fuel systems once installed on diesel locomotives, allow substituting most diesel fuel with much cheaper and cleaner gas fuels – biogas, natural gas, and syngas – without the necessity for large capital investments. This article describes a case of dual-fuel conversion of a S200/CHME3 series diesel locomotive, introducing to the system specifics, certification procedure, gas refueling infrastructure, as well as outlining the main economic and technical results. The article concludes by outlining the dual-fuel perspectives in the Polish railway industry and estimates the economic and ecological benefits its implementation can bring.