Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "HCCI engine" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
HCCI engine - idea and expectations. Case study
Autorzy:
Kowalewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/244203.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
HCCI engine
auto-ignition control
Opis:
Internal combustion engines yet have not exhausted their development possibilities in the range of economy and ecology demands. Development of SI and CI engines, which several years ago proceeded individually in-parallel, now becomes likely in common: one type of engine shares some features with the other one, e.g. direct injection, electronically controlled injectors, electronic control unit etc. However, type of ignition and mixture formation are still different (spark assisted ignition versus auto ignition and homogeneous mixture versus heterogeneous). HCCI engine overcomes this difference. At present HCCI engine uses both type of ignition modes and both types of mixture in different ranges of operational parameters. Direct injection during compression stroke and stratified charge are characteristics for low and mild power resulting in low emission of CO and HC as well as NOx. Combustion is initiated by spark when mixture is very poor. For maximum load and speed, auto-ignition of homogeneous stoichiometric mixture takes place in the whole volume of combustion chamber. Due to the absence of flame and low temperature, nitrogen oxides, of which molecules arise in post flame zone, are low. Also emission of CO and HC are low due to stoichiometry of the mixture. The key problem is controlled auto-ignition as a function of speed and load (fully HCCI engine). Several methods of auto-ignition control (CAI) are discussed in this paper.
Źródło:
Journal of KONES; 2008, 15, 2; 217-224
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Increase of high load limit in a gasoline HCCI engine
Autorzy:
Hunicz, J.
Kordos, P.
Gęca, M.
Powiązania:
https://bibliotekanauki.pl/articles/242189.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
HCCI engine
negative valve overlap
high load limit
mechanical boost
Opis:
Engine operation in HCCI mode allows for improvement of thermal efficiency and substantial reduction NOX emission. The most production feasible solution for gasoline HCCI engine is application of exhaust gas trapping using a negative valve overlap. This technique increases thermal energy of a mixture, thus allowing for auto-ignition at moderate compression ratios. However, high exhaust gas re-circulation rate decreases volumetric efficiency. As a result, achievable engine loads are also reduced. Supercharging can be applied in order to improve volumetric efficiency and extend high load limit. However, increase of amount of intake air can lead to reduction of start of compression temperature via decrease of residuals in a mixture. In order achieve HCCI mode of combustion, temperature of start of compression must be kept within narrow limits. In this study experimental and modeling investigations were presented. Experiments were carried out using single cylinder research engine. The engine was equipped with fully variable valvetrain and direct gasoline injection. Application of mechanical boosting allowed for widening achievable load range in HCCI mode of operation. Numerical calculations allowed for determination of admissible valvetrain settings and intake pressure, which guarantee proper temperature of start of compression.
Źródło:
Journal of KONES; 2012, 19, 4; 231-238
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the ignition control in the HCCI system using dose of monoatomic inert gas
Autorzy:
Postrzednik, S.
Przybyła, G.
Żmudka, Z.
Powiązania:
https://bibliotekanauki.pl/articles/248032.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
IC engine
HCCI system
ignition control
charge compression
Opis:
The subject of the analysis presented in the paper is the idea and implementation method of the ignition point of homogeneous air-fuel mixture, used in the IC engine with HCCI system. Autoignition of the combustible mixture can occur only upon reaching the characteristic self-ignition temperature Tz. It should take place during (near end) the load compression. In order to achieve the fuel mixture ignition temperature Tz in the system, usually it is proposed adjusting the engine compression ratio, epsilon. However, it is quite cumbersome especially in case of frequent changes of engine load (there are also difficulties with the precise advance angle adjusting of fuel mixture ignition). According to our conception, the other method of autoignition adjustment can be successfully applied. The essence of the new idea consists in proper selection, according to engine load, of the exponent k of charge polytropic compression. Introducing the defined dose of monoatomic gas (e.g. argon Ar,k almost equal 1.667) to air-fuel mixture, the higher values of the polytropic compression exponent .. of working medium can be achieved. It will result in significant increase of the temperature rise Delta Tmax of the compressed charge and accordingly progressive increase of the advance angle of the mixture ignition.
Źródło:
Journal of KONES; 2012, 19, 1; 319-326
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of work of an engine working with combustion initiation from ignition dose of fuel
Autorzy:
Sendyka, B.
Mitianiec, W.
Noga, M.
Powiązania:
https://bibliotekanauki.pl/articles/245989.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
modelling
simulation
combustion engine
HCCI
two stage injection system
Opis:
The paper presents analysis of fuelling and of the course of combustion process for a two-cycle engine. The main idea of the engine according to patent solution of Prof. B. Sendyka consists in the fact that engine work begins from spark ignition, whereas, at higher load and higher temperature in the cooling system there occurs switching off spark ignition and transition to ignition from an ignition dose injected directly into the combustion chamber. Such an engine possesses two injection systems: one system of multi-point injection which forms homogenous mixture, whereas, the other system of direct injection is used for ignition dose injection only. After injection of the ignition dose of a very small mass combustion is initiated on the basis of formation of auto-ignition centres so as it takes place during knock combustion. Auto-ignition centres initiate combustion of the basic charge. Simulation was carried out in order to perform analysis occurring phenomena of fuel feeding and combustion. Works on it started from elaboration of a computational grid of the engine and subsequently analysis of indicated diagrams of engine work with injection of ignition dose was performed. Analysis was also performed of temperature traces and of traces of charge mass change in the cylinder as well as of participation of the mass of basic fuel dose in the cylinder in function of the crank angle. Moreover visualization of effects of the process of mixture formation and combustion was performed and presented in form of illustrations of charge temperature distribution, fraction of fuel ignition and basic dose vapours in cross-sections of the combustion chamber.
Źródło:
Journal of KONES; 2011, 18, 3; 395-403
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies