The Journal of Engine Research

The Journal of Engine Research

Experimental investigations on a pre-chamber spark plug with variable heat range by integrating a controlled hot surface

Document Type : Original Article

Authors
Sascha Holzberger 1
Maurice Kettner 2
Roland Kirchberger 3
1 PhD Candidate, Karlsruhe University of Applied Sciences
2 Karlsruhe University of Applied Sciences
3 Graz University of Technology
10.22034/er.2022.701024
Abstract
In gasoline engines, pre-chamber spark ignition systems are used to achieve high efficiency and low NOx emissions when operating under lean conditions. While a cold pre-chamber spark plug can lead to misfiring and flame quenching under cold start or part load operation, a hot pre-chamber can result in uncontrolled pre-ignition phenomena under full load operation. This paper presents an approach to adjust the heat range of a pre-chamber spark plug and thus, the temperature of the mixture in the pre-chamber, according to the operating condition. Furthermore, higher mixture temperatures in the pre-chamber are intended to enhance the inflammation under lean conditions and to extend the lean limit. For this purpose, a glow plug is integrated into the pre-chamber, whose temperature can be controlled as a function of the operating point. A real-time closed-loop control strategy was applied by using the correlation between the glow plug tip temperature and its electrical resistance. The developed ignition element is called Hot Surface Assisted Spark Ignition (HSASI). In addition to a functional test, a variation of the engine temperature was performed on a single-cylinder, gasoline fueled research engine at the Karlsruhe University of Applied Sciences. In the first step, the influence of the glow plug assistance on the flame development angle and the combustion stability was determined. Subsequently, the air-fuel equivalence ratio λ was varied and the lean limit of unassisted and glow plug assisted spark ignition were determined. Experimental investigations for a constant air-fuel equivalence ratio and a constant ignition timing show that a higher glow plug resistance and thus a higher glow plug temperature shortens the flame development angle and shifts the center of combustion to earlier crank angles. Furthermore, the positive influence of the active glow plug on the flame development angle and the combustion stability increases with retarded ignition timing. With λ = 1.5 and a constant center of combustion (8 °CA after top dead center firing), the ignition timing can be retarded by 4.5 °CA. When operating with lower coolant temperature, an active glow plug increases combustion stability and extends the lean limit by Δλ = 0.1.
Keywords
Pre-chamber spark plug
Glow plug
Heat range
[1] Kettner, M. “Zündsysteme für magere Gemische”, Study for the Forschungsvereinigung Verbrennungskraftmaschinen(FVV)e.V., 2004.
[2] Amirante, R., Distaso, E., Tamburrano, P. and Reitz, R.D., “Laminar flame speed correlations for methane, ethane, propane and their mixtures, and natural gas and gasoline for spark-ignition engine simulations” International Journal of Engine Research 18(9): p. 951-970, 2017, doi:10.1177/1468087417720018.
[3] Ozdor, N., Dulger, M., and Sher, E., “Cyclic Variability in Spark Ignition Engines - A Literature Survey,” 940987, SAE Technical Paper, 1994, doi:10.4271/940987.
[4] Müller C., Morcinkowski B., Schermus C., Habermann K. et al., “Development of a Pre-chamber for Spark Ignition Engines in Vehicle Applications,” in: Ignition Systems for Gasoline Engines: 4th International Conference, December 6-7: p. 261-274.
[5] Wöbke, M., Reinicke, P.-B., Rieß M., von Römer L. et al., “Characterization of the Ignition and Early Flame Propagation of Pre-Chamber Ignition System in a High-Pressure Combustion Cell” in: Ignition Systems for Gasoline Engines: 4th International Conference: p. 385-423.
[6] Wang, B. and Wang, Z., “Experimental Research on Pre-chamber Jet Ignition in Rapid Compression Machine and Natural Gas Engine,” in: Ignition Systems for Gasoline Engines: 4th International Conference: p. 424-441.
[7] Toulson, E., Schock, H.J., and Attard, W.P., “A Review of Pre-Chamber Initiated Jet Ignition Combustion Systems,” SAE International, 2010, doi:10.4271/2010-01-2263.
[8] Sens, M. and Binder E., “Vorkammerzündung als Schlüsseltechnologie für einen zukünftigen Antriebsstrang-Mix,” MTZ Motortechnische Zeit-schrift 80(02): p. 46-53, 2019.
[9] Kettner, M., “Experimentelle und numerische Untersuchungen zur Optimierung der Entflammung von mageren Gemischen bei Ottomotoren mit Direkteinspritzung,” Ph.D. Thesis, Universität Karlsruhe, 2006.
[10] Sotiropoulou, E., Knepper S., Deeken, S., and Grewe, F., “Zero Emission-Die Evolution von Erdgas zu Wasserstoff mit Vorkammerzündkerzen,” MTZ Motortechnische Zeitschrift: p. 50-55, 2020, doi:10.1007/s35146-020-0231-y.
[11] Sotiropoulou, E. and Tozzi, L., “Active Scavenge Prechamber,” PCT/US2014/024904, 2016.
[12] Sens, M., Binder E., Benz A., Krämer L. et al., “Pre-Chamber Ignition as a Key Technology for Highly Efficient SI Engines – New Approaches and Operating Strategies,” in: 39. Wiener Motorensymposium.
[13] Takashima, Y., Tanaka, H., Sako, T., and Furutani, M., “Evaluation of Engine Performance and Combustion in Natural Gas Engine with Pre-Chamber Plug under Lean Burn Conditions,” SAE Int. J. Engines 8(1): 221–229, 2015, doi:10.4271/2014-32-0103.
[14] Marko F. and Koenig G., “Zuführungs- und Zündvorrichtung für einen Gasmotor und Verfahren zum Betrieb einer Zuführungs- und Zündvorrichtung für einen Gasmotor,” DE 10 2017 009 607 A1.
[15] Holzberger S., Kettner M., and Kirchberger R., “Hot Surface Assisted Spark Ignition (HSASI) - An Approach to Vary the Heat Range of Spark Plugs during Operation” Reports on Energy Efficient Mobility, 2021.
[16] Scholl, F., “Study of Premixed Combustion Induced by Controlled Hot Surface Ignition in Stationary Gas Engines,” Ph.D. Thesis, University of Valladolid & Hochschule Karlsruhe, 2017.
[17] Heywood, J., “Internal Combustion Engine Fundamentals,” McGraw-Hill, ISBN 0-07-028637-X, 1988.

  • Receive Date 04 February 2022
  • Revise Date 19 May 2022
  • Accept Date 19 May 2022