Steffen Bohne

Results from Gasoline and CNG Engine Tests with the Corona Ignition System EcoFlash

Corona ignition systems provide a spatially extended non-thermal plasma with significantly better ignition properties than spark ignition systems. This article summarizes results from engine tests on different passenger car and stationary natural gas engines with the corona ignition system EcoFlash.

Comparative Optical and Thermodynamic Investigations of High Frequency Corona- and Spark-Ignition on a CV Natural Gas Research Engine Operated with Charge Dilution by Exhaust Gas Recirculation

Investigations are presented comparing the conventional spark ignition system with a high frequency corona ignition system at a single cylinder heavy duty truck type engine with optical access to the combustion chamber through a large piston window. The focus of the thermodynamic as well as the optical studies lies on the evaluation of the ignition system with regard to an increase of the maximum EGR Rate as well as on a reduction of cyclical variations. Further considerations are the influence of specific parameters of the corona ignition system, such as ignition duration and ignition voltage on the initial flame kernel formation. For the underlying combustion concept, the corona ignition system was found to offer a high potential for a significant increase of the EGR compatibility.

Corona ignition for natural gas engines with charge dilution

Triggered by upcoming legislation enforcing lower CO2 emissions, CNG as an alternative fuel for passenger car engines has recently gained more importance. As the CO2 emission of a natural gas engine is on average 20 % lower as compared to its gasoline counterpart, CNG engines play an important role in reaching the prescribed fleet average CO2 emission limits. Consequently the last few years saw the introduction of CNG applications in different vehicle classes from almost every larger OEM, especially in Europe. In addition, particle emissions are close to zero which is an important advantage over Diesel engines. Per today’s legislation CNG as a fuel benefits from lower taxation resulting in substantial cost savings for the customer, which at least partially compensates for the additional cost of the CNG system.