Determination of thermal efficiency of the spark ignition systems
Treść / Zawartość
The paper presents results of measurements performed to determine thermal efficiency of spark ignition systems. Because of small pressure change after sparking process smali volume chamber has been proposed for measurements. A direct measurement method of pressure increment determination has been chosen. In this method one pressure chamber is used. The caloric chamber isfilledwith nitrogen, which is a neutral gas. It is preferable medium than air because it is one-component gas and it has a precisely-known value of a specific gas constant. The value of speciflc gas constant is reąuested to calculate a value of discharge energy given to the gas. In the chosen method pressure increment in the chamber during spark discharge is measured. The pressure increment in the chamber during ignition is strictly related to the energy of spark discharge. The energy balance calculations determined values of heat los s es for two types of electrodes (normal and "thin") anddifferent initial pressure (p=0 bar and p=25 bar). The maximal value of the thermal efficiency was observedfor the higher value of pressure in chamber and thin electrodes of spark ping. It was also stated, that the higher thermal efficiency for" thin " spark ping electrodes is a result of reduced heat transfer. The paper presents results of the tests carried out in the caloric chamber of 4. l cm3 filled with nitrogen at ambient temperature using PCB transducer direct measurement method. Results of the measurements done using differential pressure transducer for the same parameters like in thefirst measurement method were similar.
Bibliogr. 12 poz., rys.
-  Thiele, M., Selle, S., Riedel, U., Warnatz, J., Maas, U., A Detailed Numerical Study of Spark Ignition Including Ionization, SAE 2002-01-1110, SAE 2002 World Congress, Detroit 2002.
-  Chen, Y., Lewis, W. I., Visualization of laser-induced breakdown and ignition, Optic Express 360, No. 7, Vol. 9, 2001.
-  Thiele, M., Selle, S., Riedel, U., Warnatz, J., Maas, U., Numerical simulation of spark ignition including ionization, Proceedings of the Combustion Institute, Vol. 28, pp. 1177-1185, 2000.
-  Selle, S., Riedel, U., Transport Coefficients of Reacting Air at High Temperatures, American Institute of Aeronautics and Astronautics AIAA 2000-0211, 38 Aerospace Sciences Meeting&Exhibit, Reno 2000.
-  Yasar, O., et al, A New Spark Ignition Method for KIVA Engine Modelling, Oak Ridge National Laboratory, Oak Ridge 1998.
-  Eriksson, L., Spark Advance Modeling and Control, Linköping Studies and Technology Dissertations, No. 580, Linköping University, Linköping 1999.
-  Szargut, J., Termodynamika techniczna, PWN, Warszawa 1991.
-  Heywood, J., Internal Combustion Engine Fundamentals, Mc-Graw Hill, New York 1988.
-  Ramos, J. I., Internal combustion modeling, Hemisphere Publishing Corporation, New York 1989.
-  Maly, R., Vogel, M., Initiation and propagation of Flame Fronts in Lean CH4 – Air Mixtures by a Three Modes of the Ignition Spark, Seventeenth Symphosium on Combustion, pp. 821-831, The Combustion Institute, Pittsburgh 1979.
-  Ballal, D., Lefebvre, A., The Influence of Flow Parameters on Minimum Ignition Energy and Quenching Distance, 15th Symposium on Combustion, pp. 1737-1746, The Combustion Institute, Pittsburgh 1981.
-  Liu, J., Wang, F., Lee, L., Theiss, N., Ronney, P., Gundersen, M., Effect of Discharge Energy and cavity Geometry on Flame Ignition by Transient Plasma, 42nd Aerospace Sciences Meeting, 6th Weakly Ionized Gases Workshop, Reno, Nevada 2004.