Analysis of mass transfer in marine engine with prechamber combustion spark ignition system

Abstract

The development of combustion systems construction is associated with the possibilities of increasing the thermal or overall efficiency of an internal combustion engine. The combustion systems currently in use (mainly related to direct fuel injection) are increasingly being replaced by hybrid systems: including direct and indirect injection. Another alternative is the use of pre-chambers in new combustion systems. This article is concerned with the thermodynamic aspect of this issue – namely the assessment of inter-chamber flow of a marine engine equipped with a Prechamber Combustion Spark Ignition system. The research was carried out using mainly one-dimensional simulation apparatus, and detailed analyzes were presented with the use of three dimensional modeling. The tests concerned the engine model at medium load. Differences in mass flows were shown at different diameters and different number of holes from the preliminary chamber (while maintaining the same cross-sectional area). Similar values of excess air coefficient during ignition of the fuel dose in the pre-chamber were observed, which resulted in changes in the flow between the prechamber and the main chamber. The differences in mass flow affected the temperatures achieved in the individual combustion chambers. Based on threedimensional analyzes, the mass transfer rate between the chambers and the temperature distribution were assessed during fuel ignition initiated in the prechamber.