Stratified liquefied petroleum gas—dimethyl ether compression ignition engine combustion at various intake valve open timings

Abstract

The combustion and exhaust emissions characteristics of compression ignition engine with a variable valve timing device were investigated for liquefied petroleum gas (LPG) and dimethyl ether (DME) under various LPG injection timing conditions. LPG was used as the main fuel injected directly into the combustion chamber. DME was used as an ignition promoter injected into the intake port. Different LPG injection timings were tested to verify the effects of the mixture homogeneity on the combustion and exhaust emission characteristics of the LPG and DME compression ignition engine. The average charge temperature was calculated to analyse the pollutant formation. The ringing intensity was used for the analysis of knock characteristics.

The combustion and exhaust emission characteristics differed significantly depending on the LPG injection and intake valve open timings. The carbon monoxide (CO) emission increased as the intake valve opened and LPG injection timings were retarded owing to the local mixture inhomogeneity. However, the particulate matter (PM) emission decreased and the nitrogen oxides (NO _x ) emission increased as the intake valve open timing was retarded in the diffusion combustion regime. Finally, the combustion efficiency decreased as the intake valve open and LPG injection timings were retarded.

Keywords

stratified charge HCCI (homogeneous charge compression ignition)LPG (liquefied petroleum gas)DME (dimethyl ether)

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References

Zhao

Asmus

Assanis

Dec

Eng

Najt

, Homogeneous charge compression ignition (HCCI) engines: Key research and development issues (: Society of Automotive Engineers 2003)

Yeom

Jang

Bae

, ‘Homogeneous charge compression ignition of LPG and gasoline using variable valve timing in an engine.’ Fuel 86 (2007): 494–503

Thirouard

Cherel

Knop

, ‘Investigation of mixture quality effect on CAI combustion.’ SAE Trans. 114 (3) (2005): 311–330

Ogawa

Miyamoto

Kaneko

Ando

, ‘Combustion control and operating range extension in an homogeneous charge compression ignition engine with direct in-cylinder injection of reaction inhibitors.’ Int. J. Engine Res. 6 (4) (2005): 341–360

Sankaran

, ‘Characteristics of auto-ignition in a stratified iso-octane mixture with exhaust gases under homogeneous charge compression ignition conditions.’ Combust. Theory Modelling. 9 (2005): 417–432

Ying

Longbao

Hewu

, ‘Diesel emission improvements by the use of oxygenated DME/diesel blend fuels.’ Atmos. Environ. 40 (2006): 2313–2320

Griffiths

MacNamara

Sheppard

Turton

Whitaker

, ‘The relationship of knock during controlled autoignition to temperature inhomogeneities and fuel reactivity.’ Fuel 81 (2002): 2219–2225

Eng

, ‘Characterization of pressure waves in HCCI combustion.’ SAE paper 2002-01-2859

Bertola

Stadler

Walter

Wolfer

Gossweiler

Rothe

, ‘Pressure indication during knock conditions.’ In Proceedings of the 7th International Symposium on Internal combustion diagnostics, Kurhaus Baden-Baden, Germany

10.

Filipi

Chang

Guralp

Assanis

Kuo

Najt

Rask

, ‘New heat transfer correlation for an HCCI engine derived from measurements of instantaneous surface heat flux.’ SAE Trans. 113 (3) (2004): 1576–1593

11.

Zhao

Ladommatos

, Engine combustion instrumentation and diagnostics (: Society of Automotive Engineers 2001)

12.

Tsurushima

Shimazaki

Asaumi

, ‘Gas sampling analysis of combustion processes in a homogeneous charge compression ignition engine.’ Int. J. Engine Res. 1 (4) (2000): 337–352

13.

Sjoberg

Dec

, ‘An investigation into lowest acceptable combustion temperatures for hydrocarbon fuels in HCCI engines.’ Proc. Combust. Inst. 30 (2005): 2719–2726

14.

Bhave

Kraft

Montorsi

Mauss

, ‘Sources of CO emissions in an HCCI engine: A numerical analysis.’ Combust. Flame 144 (2006): 634–637

15.

Mondal

Datta

Sarkar

, ‘Droplet size and velocity distributions in a spray from a pressure swirl atomizer: Application of maximum entropy formalism.’ Proc. IMechE, Part C: J. Mechanical Engineering Science 218 (C7) (2004): 737–750 DOI: 10.1243/0954406041319563

16.

Tree

Svensson

, ‘Soot processes in compression ignition engines.’ Prog. Energy Combust. Sci. 33 (2007): 272–309

17.

Stojkovic

Fansler

Drake

Sick

, ‘High-speed imaging of OH and soot temperature and concentration in a stratified-charge direct-injection gasoline engine.’ Proc. Combust. Inst. 30 (2005): 2657–2665

18.

Drake

Fansler

Lippert

, ‘Stratified-charge combustion: Modeling and imaging of a spray-guided direct-injection spark-ignition engine.’ Proc. Combust. Inst. 30 (2005): 2683–2691

19.

Yeom

Bae

, ‘Gasoline—di-methyl ether homogeneous charge compression ignition engine.’ Energy Fuels 21 (2007): 1942–1949

20.

Lee

, ‘An experimental study of the extent of the operating region and emission characteristics of stratified combustion using the controlled autoignition method.’ Energy Fuels 20 (2006): 1862–1869