Wyniki wyszukiwania - BazTech

1

Analysis of heat release in compression ignition engine

Tutak W., Gnatowska R., Winczek J., Gawrońska E.

Prace Naukowe Akademii im. Jana Długosza w Częstochowie. Technika, Informatyka, Inżynieria Bezpieczeństwa

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2017

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T. 5

67--74

EN

The main goal of this research was to analyze the heat release in a compression ignition (CI) engine. Work contains description of the combustion process in the combustion chamber of CI engine with an explanation of the combustion stages. The research was conducted for wide range of load. At full load of engine achieved the highest value of pressure rise, temperature, fuel consumption and indicated mean effective pressure. The lowest values of these parameters were obtained for the smallest load. The full load of engine was characterized by the highest value of the heat release, and the longest combustion period due to the large share of diffusion combustion phase. The lowest load was characterized by 3.5 times less in value of heat release than in case of maximum load and heat release rate course was without visible diffusion combustion phase.

PL

Głównym celem badań było przeprowadzenie analizy wydzielania ciepła w silniku o zapłonie samoczynnym. Badana jednostka to sześciocylindrowy silnik z zapłonem samoczynnym o mocy 80 kW, poddany obciążeniom w szerokim zakresie. Dla obciążenia maksymalnego uzyskano największy przyrost ciśnienia, temperatury, godzinowego zużycia paliwa oraz ciśnienia indykowanego. Najmniejsze wartości powyższych parametrów zostały uzyskane dla najmniejszego obciążenia. Obciążenie maksymalne charakteryzuje się najwyższą ilością wydzielonego ciepła, a także najdłuższym procesem spalania za sprawą dużego udziału spalania dyfuzyjnego. Przy obciążeniu minimalnym wydzielania ciepła było 3,5- krotnie mniej niż dla maksymalnego, ponadto proces spalania trwał najkrócej, bez widocznego udziału spalania dyfuzyjnego.

2

Numerical calculation of rotating detonation chamber

Shi Z., Kindracki J.

Journal of Power Technologies

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2017

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Vol. 97, nr 4

314--326

EN

ANSYS FLUENT 14 supplied the CFD tools used in the numerical calculation of rotating detonation combustion. During calculations, various fuel injection methods and configurations of combustion chamber were applied in an attempt to obtain stable and correct detonation propagation results in a separated fuel-air injection system (non-premixed combustion model). However, FLUENT was not originally designed for detonation combustion and the failure to achieve re-initiation of detonation after collision was always the core issue in the non-premixed combustion model. Thus, this paper mainly focuses on research into the behavior of stable continuously rotating detonation in premixed combustion cases. The analysis of stable continuously rotating detonation behaviors and structures was carried out with different boundary conditions and mesh cells. The pressures were measured by using a number of artificial sensors inserted near the chamber outside surface in various axial and/or circumferential directions. With those key results in the case of premixed combustion, we were able to comparably conclude that stable rotating detonation would also be generated if the refilling process were properly exhibited in non-premixed combustion. The paper finishes with evaluations and conclusions regarding general detonation behaviors and performances.

3

Fuzzy controller for a lean premixed burner

Smolarz A., Wójcik W., Ballester J., Hernandez R., Sanz A., Golec T.

Przegląd Elektrotechniczny

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2010

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R. 86, nr 7

287-289

EN

The article describes application of a fuzzy controller for a lean premixed combustion of carbon dioxide and/or hydrogen rich methane biogases in gas turbine burners. The authors present theoretical background and some experimental results with pure methane and CO2 blends, that confirm the assumed approach.

PL

Artykuł opisuje zastosowanie regulatora rozmytego do sterowania procesu spalania ubogiej mieszanki biogazu bogatego w dwutlenek węgla lub wodór w turbinach gazowych. Autorzy przedstawiają podstawy teoretyczne oraz rezultaty badań eksperymentalnych z czystym metanem oraz jego mieszankami z CO2 , które potwierdzają słuszność przyjętego podejścia.

4

The effect of injection pressure and strategy in a Jaguar V6 diesel engine

Abdullah N. R., Mamat R., Rounce P., Wyszynski M. L., Tsolakis A., Xu H. M., Tian G.

Journal of KONES

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2009

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Vol. 16, No. 2

9-22

EN

In recent years, the improvement of engine performance and emissions has become an extremely important concern. This study focuses on the injection strategy based on the injection pressure (IP) and duration between pilot injection and the main injection (dMI) using a multi cylinder common rail multiple injections diesel engine. The study was designed to produce improvements in fuel mixing via the injection strategy, to reduce the main ignition delay. This would contribute to a minimum amount of fuel burnt in the premixed combustion phase, leading to a reduction in emissions. Recent evidence shows that premixed combustion is significant in the controlling of emissions of nitrogen oxides (NOx) and soot. Six different IPs combined with a short and long dMI were compared in the attempt to improve engine performance and emissions. The engine performance was measured in terms of brake specific fuel consumption, ignition delay, heat release and peak in-cylinder pressure and emissions, specifically nitrogen oxides (NOx), total unburned hydrocarbons (THC), carbon monoxide (CO) and smoke emissions for each engine test condition. The evidence from this study shows that the effect of IP is more dominant than dMI in terms of peak cylinder pressure, heat release, brake specific fuel consumption and emissions. However, the dMI shows a strong effect at a higher engine speed.

5

Pomiary szybkości spalania mieszanki eteru dimetylowego z powietrzem przy użyciu techniki mikrociążenia

Okajima S.

Silniki Spalinowe

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2005

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R. 44, nr 3

56--60

PL

Przeprowadzono doświadczenie, którego celem było sprawdzenie charakterystyki spalania mieszanki powietrza i eteru dimetylowego przy wykorzystaniu technikę mikrociążenia, wymagające komory swobodnego opadania. Warunki początkowe badań były następujące: temperatura 293 K, ciśnienie 0,10 MPa a stosunek składników mieszaniny zmieniał się od stechiometrycznego do granic zapalności mieszanki. Uzyskano następujące wyniki: (1) technika mikrociążenia jest bardzo użyteczna w analizie zachowania płomienia, nawet dla bardzo ubogich mieszanek, oraz (2) szybkość spalania mieszanki eteru dimetylowego jest podobna do prędkości spalania metanu w całym zakresie analizowanych składów mieszaniny i wynosi 10,0 cm/s oraz 32,0 cm/s, odpowiednio dla mieszanki o stosunku 0,62 i 0,90 a także (3) na podstawie wyników badań można wnioskować, że użycie mieszanki z eterem dimetylowym nie jest wykluczone w przypadku silników.

EN

Experiment has been carried out to examine the fundamental combustion characteristics of DME fuel-air mixtures using micro-gravity technique, which is achieved in freely falling chamber. The initial conditions of temperature and pressure are 293 K and 0.10 MPa, respectively and the equivalence ratio is the range from stoichiometoric proportion to near the lower flammability limit. The results obtained in the study are as follows:(1) micro-gravity technique is very useful to analyze the flame behavior even at very lean mixtures, and (2) the burning velocity of DME fuel- air mixture is nearly the same with that of methane-air mixture at the range of all the equivalence ratios investigated and those values of DME fuel are 10.0 cm/s and 32.0 cm/s at 0.62 and 0.90 of equivalence ratio, respectively, and (3) from these experimental data it is suggested that the application to the engine combustion of DME fuel is not so impossible.

6

Chemistry-turbulence coupling in a model of inhomogenously premixed combustion

Badur J., Karcz M., Wysocki T.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2003

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Vol. 7, No 3

337-346

EN

Results of work on an extension of the turbulent flame speed model used for a mathematical description of partially premixed combustion are presented. The approach is based on the concept of internal coupling between the turbulence of the mixed fuel and oxidizer stream with the reaction progress variable. The model after implementation has been calibrated and tested on a BERL benchmark experiment.