Injection strategies for low HC raw emissions in SI engines with CNG direct injection
Tóm tắt
The energy source natural gas represents an attractive alternative fuel for SI engines due to its suitable chemical properties. But the lower performance yield and the insufficient infrastructure lead to a rejection by the customer. One approach to gain acceptance is the improvement of the driveability of the natural gas-powered vehicles. Direct injection of CNG is a technology with potential to achieve this objective. Nevertheless, the combustion concept has high requirements on injection system and mixture formation. Among other challenges the methane slip raises major issue. The compact molecular structure of the CNG’s main component, methane, leads to an extremely slow reactivity, which expresses itself in a higher catalytic converter light-off temperature and thus aggravated exhaust aftertreatment. Especially, since methane’s global warming potential is 21 times higher than CO2, the greenhouse gas footprint is getting worse again. Thus, for the future implementation of such a combustion system concept it will be necessary to compensate the limited conversion rates of the catalytic converter with low raw emissions. For this, the comprehension of the mixture formation is necessary. This paper deals with different injection strategies at part load and charged operation to achieve HC raw emissions as low as possible. The test-bench experiments are executed with a two-cylinder SI engine under homogeneous stoichiometric conditions. The DI injector used for this study is a prototype model fabricated by Robert Bosch GmbH. In summary, the need of adaption of the injection strategy to the respective engine map area is becoming evident. Furthermore, various injection timings and injection splitting strategy turned out as an appropriate measure to make the most of CNG-DI’s potential and to achieve low HC raw emissions.
Tài liệu tham khảo
Warnecke, W., Karanikas, J., Levell, B., Mesters, C., Schreckenberg, J., Adolf, J.: Gas—a bridging technology for future mobility? 34. Internationales Wiener Motorensymposium (2013)
Europäische Union: Verordnung (EG) Nr. 715/2007 des Europäischen Parlaments und des Rates (2007)
Biemelt, A.: Der dynamische Erdgasantrieb. ATZ/MTZ Konferenz—Motor, Stuttgart (2009)
Pischinger, S.: Entwicklung beim PKW-Motor spannender denn je. MTZ Motortechnische Zeitschrift 75(07), 42–47 (2014)
Weber, C., Kramer, U., Klein, R., Hofmann, C., Berkemeier, O., Dunstheimer, J., Baumgarten, H., Uhlmann, T., Thewes, M., Scharf, J., Ewald, J.: Erdgas-spezifisches Downsizing—Potenziale und Herausforderungen. 36. Internationales Wiener Motorensymposium (2015)
Heidt, C., Lambrecht, U., Hardinghaus, M., Knitschky, G., Schmidt, P., Weindorf, W., Naumann, K., Majer, S., Müller-Langer, F., Seiffert, M.: CNG und LPG—Potenziale dieser Energieträger auf dem Weg zu einer nachhaltigeren Energieversorgung des Straßenverkehrs. Kurzstudie des Bundesministerium für Verkehr, Bau und Stadtentwicklung (BMVBS) AZ Z14/SeV/288.3/1179/UI40 (2013)
Czerwinski, J., Heeb, N., Zimmerli, Y., Forss, A.-M., Hilfiker, T., Bach, C.: Unregulated emissions with TWC, Gasoline and CNG. SAE-Paper 2010-01-1286
Beutler, M., Naumann, M.: Erdgas—Ein alternativer Kraftstoff für den Verkehrssektor. ATZ Automobiltechnische Zeitschrift 100(9), 648–656 (1998)
Bräuninger, M., Schröer, S., Schulze, S., Vöpel, H.: CO2-Einsparpotenziale des Energieträgers Erdgas. Zfe Zeitschrift für Energiewirtschaft (11), S. 37–45 (2008)
Fricke, F., Lang, O., Habermann, K., Rütten, O.: Brennverfahrenskonzepte zur Darstellung von CNG-Antrieben. 10. Tagung Der Arbeitsprozess des Verbrennungsmotors (2005)
Otto, F., Rößler, K., Bertram, C., Fürhaupter, A.: Potentiale des aufgeladenen monovalenten Erdgasmotors beim PKW: 11. Tagung Der Arbeitsprozess des Verbrennungsmotors, (2007)
Husted, H., Karl, G., Schilling, S., Weber, C.: Direct injection of CNG for driving performance with low CO2. 23. Aachener Kolloquium (2014)
Preuhs, J.F., Hoffmann, G., Kirwann, J.: Natural gas direct injection for low CO2 spark ignition engines. 27. SIA Powertrain, Versailles (2015)
Zeng, K., Huang, Z., Liu, B., Liu, L., Jiang, D., Ren, Y., Wang, J.: Combustion characteristics of a direct-injection natural gas engine under various fuel injection timings. Appl. Therm. Eng. 26, 806–813 (2006)
Hayashida, M., Yamato, T., Sekino, H., Sugahara, K.: Investigation of performance and fuel distribution of a direct injection gas engine using LIF Measurement. SAE-Paper 1999-01-3291
Hofherr, T., Damböck, M., Forsthuber, F., Hofmann, P.: Potential of direct injection for increasing the low-end torque of boosted CNG engines. 8. Tagung Gasfahrzeuge, Stuttgart (2013)
Schwarzer, H.-C., Gremminger, A., Deutschmann, O.: Untersuchung der Wirkmechanismen bei katalytischer Methanreduktion. FVV (Nr. 1134)—Abschlussbericht, Heft R566, Magdeburg (2014)
Heywood, J.B.: Internal combustion engine fundamentals. McGraw-Hill, Inc., ISBN: 0-07-028637-X (1988)
Dinkelacker, F., Kuppa, K., Wachtmeister, G., Korb, B.: Ursachen und Reduktionsmaßnahmen von THC-Emissionen in Gasmotoren. FVV (Nr. 1127)—Zwischenbericht, Heft R568, Dortmund (2014)
Mohammed, S.E., Baharom, M.B., Aziz, A.R.A., Firmansyah.: The effects of fuel-injection timing at medium injection pressure on the engine characteristics and emissions of a CNG-DI engine fueled by a small amount of hydrogen in CNG. Int. J. Hydrog. Energ. 36, 11997–12006 (2011)
Kalam, M.A., Masjuki, H.H., Mahlia, T.M.I., Fuad, M.A., Halim, K., Ishak, A., Khair, M., Yusoff, A., Shahrir, A.: Experimental test of a new compressed natural gas engine with direct injection. SAE-Paper (2009)
Chiodi, M., Berner, H.-J., Bargende, M.: Investigation on different injection strategies in a direct-injected turbocharged CNG-engine. SAE-Paper (2006)
Hassan, M.K., Aris, I., Mahmod, S., Sidek, R.: Influence of injection and ignition of CNG fuelled direct injection engine at constant speed. Aust. J. Basic Appl. Sci. 4, 4870–4879 (2010)
Hofmann, P., Hofherr, T., Damböck, M.: Der CULT Antrieb: Hocheffizienter CNG Motor mit Direkteinblasung. 34. Internationales Wiener Motorensymposium (2013)
Soltic, P., Egli, R., Mauke, D., Wright, Y.M., Bach, C., Boulouchos, K.: Strömung, Gemischbildung und Verbrennung bei Methandirekteinblasung im homogenen λ = 1 Betrieb: Simulationen und Versuchsergebnisse. 6. Tagung Gasfahrzeuge, Stuttgart (2011)
Hu, R., Schmitt, M., Wright, Y.M., Boulouchos, K.: A simulation method for 3-D CFD modeling of supersonic gas injection in DI gas-powered engines. 9. Tagung Gasfahrzeuge, Potsdam (2014)
Rashid, A., Aziz, A.R.A., Firmansyah.: The effect of fuel rail pressure on the performance of a CNG-direct injection engine. SAE-Paper (2009)
Bohatsch, S., Hofmann, B., Ferrari, A., Chiodi, M., Berner, H.-J., Bargende, M.: Gasfahrzeuge II—Darstellung verschiedener Betriebsstrategien an einem Erdgasmotor mit innerer Gemischbildung. Haus der Technik Fachbuch, Band 69, S. 78–103, ISBN-13: 978-3-8169-2650-4 (2006)
Eichhorn, A., Lejsek, D., Hettinger, A., Kufferath, A.: Challenge determining a combustion system concept for downsized SI-engines—comparison and evaluation of several options for a boosted 2-cylinder SI-engine. SAE-Paper (2013)
Kistler Gruppe: Datenblatt Kistler (2014)
Kistler Gruppe: Datenblatt Kistler (2014)
Kistler Gruppe: Datenblatt Kistler (2014)
AVL List GmbH: Modular Indicating Systems. https://www.avl.com/deDE/-/modular-indicating-systems (Mai 2015)
Kulzer, A., Lejsek, D.: BeCAT—Bosch engine combustion analysis tool: user manual. Robert Bosch GmbH (2010)
HORIBA Ltd.: MEXA-7100FX. http://www.horiba.com/automotivetest-systems/products/emission-measurement-systems/analyticalsystems/standard-emissions/details/mexa-7100fx-899/ (Mai 2015)
Testa GmbH: Datenblatt Testa FID (2014)
Seboldt, D., Lejsek, D., Bargende, M.: Untersuchungen zum Einfluss von Einblasebeginn und Einblaserichtung auf die Gemischbildung und Verbrennung an einem λ = 1 betriebenen Ottomotor mit CNG-Direkteinblasung. 10. Tagung Gasfahrzeuge, Stuttgart (2015)