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1

Analysis of the ignition control in the HCCI system using dose of monoatomic inert gas

Postrzednik S., Przybyła G., Żmudka Z.

Journal of KONES

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2012

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Vol. 19, No. 1

319-326

EN

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.

2

Korekcja charakterystyk sterujących pracą silnika ZI w mikroprocesorowym modelu sterownikaw mikroprocesorowym modelu sterownikaw mikroprocesorowym modelu sterownikaw mikroprocesorowym modelu sterownikaw mikroprocesorowym modelu sterownika

Podleśny M., Walusiak S., Pietrzyk W.

Przegląd Elektrotechniczny

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2008

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R. 84, nr 3

228-230

PL

W pracy przedstawiono możliwości wykorzystania zbudowanego mikroprocesorowego sterownika silnika ZI. Przedstawione zostaną przykładowe algorytmy sterowania, umożliwiające wprowadzanie korekcji charakterystyk wyprzedzenia zapłonu i czasu wtrysku silnika w zależności od zmian warunków pracy.

EN

The paper presents possibilities offered by the application of an elaborated microprocessor controller for spark-ignition engines. Example control algorithms that make possible to introduce corrections to the characteristics of ignition advance and injection time depending on varied operation conditions have been presented.

3

Ignition control in the hcci combustion engine system fuelled with methanol-reformed gases

Shudo T.

Journal of KONES

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2005

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Vol. 12, No. 3-4

233-244

EN

Homogeneous charge compression ignition (HCCI) combustion enables higher thermal efficiency and lower NOx emission to be achieved in internal combustion engines compared to conventional combustion systems. A new concept HCCI engine system fueled with dimethyl ether (DME) with a high cetane number and methanol-reformed gas (MRG) with high anti-knock properties has been proposed by the author et al. In the system, both DME and MRG are to be produced from methanol by onboard reformers utilizing the engine exhaust heat. It has been shown that adjusting the fraction of the two fuels effectively controls the duration of the low-temperature oxidation and the onset of the high-temperature oxidation in HCCI. The ignition control expands the operable range of equivalence ratio and engine load. Lean combustion by HCCI operation and a waste heat recovery by the fuel reforming utilizing engine exhaust heat achieve a high overall thermal efficiency. While MRG consists of hydrogen and carbon monoxide, the ignition control effect of MRG is attributed mostly to hydrogen. The current paper reviews the characteristics of the HCCI engine system fuelled with methanol reformed gases.

4

Formaldehyde for the premixed compression-ignition engine - an additive for ignition-timing control -

Yamaya Y, Furutani M., Ohta Y.

Journal of KONES

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2002

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Vol. 9, No. 1-2

291-297

EN

Lean fuel/air mixtures with various fuel/fuel ratios between methane and n-butane were supplied to a premixed compression-ignition engine (i.e. homogeneous charge compression ignition engine, HCCI) with or without supplementary gaseous formaldehyde induction as an ignition controlling additive. In the no additive case the methane and butane function as the two fuels in the high/low-octane two-fuel premixed compression-ignition operation we proposed previously as another ignition control procedure. The formaldehyde addition to the methane/ butane/air mixtures has given the engine desired and stable ignition timings controllable by the amount of formaldehyde to be added, almost independent on the fuel/fuel ratios between methane and butane. The efficacy of formaldehyde has been confirmed as an ignition controlling medium for the piston-compression ignition of hydrocarbon/air mixtures.

5

A key to achieve ignition carbon monoxide generation/consumption in blueźflame period during hydrocarbon compression ignition

Furutani M., Ohta Y., Nose M.

Journal of KONES

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2001

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Vol. 8, No. 1-2

1-8

EN

A criterion between success and failure of marginal fuel/air compression ignition was searched for using a rapid compression machine. A barely achieved ignition process was compared to a case no ignition was established due to a slightly insufficient compression pressure level. The differential on the chemical species histories during the induction periods between both cases was examined by continual diff'erent-timing gas samplings. A distinguished difference could be found only on the carbon-monoxide/carbon-dioxide ratio between the flammable and nonflammable critical conditions. The ratio increased continuously in the ignition success cases. There were no differences in other species concentration, such as gaseous water. hydrogen, formaldehyde and ethy lene . At the tim e just before the final hot-flame onset the carbon-monoxide concentration came up to around 7 000 ppm, independent of the mixture strength. A steady carbon-monoxide/carbondioxide ratio was observed in the case no hot-flame onset was established . Continuous growing of carbon monoxide during the blue-flame period would be an indication fo r the transfer to the final hot-flame ign ition.