Dual fuel engine injector temperature monitoring: An innovative thermal analysis approach

Abstract

Fuel injectors in internal combustion engines, playing a crucial role, are subject to high thermal loads. Analyzing heat transfer in these components is of paramount importance. Therefore, this study focuses on numerical modeling of injector temperature to ensure spatial and temporal monitoring under various operating conditions. The impact of combustion mode is considered, particularly in dual fuel combustion scenarios, where injector cooling is reduced due to the limited quantity of liquid fuel injected. To accurately consider the effect of the injector environment, the model developed subdivides the injector into several zones depending on the boundary conditions. For each zone, the boundary is controlled by conduction managed by an adiabatic temperature and a heat transfer coefficient, which are determined according to the operating conditions that change with the crank angle. These two parameters are averaged and introduced as boundary conditions in the Ansys-FLUENT code where the conductance equations are solved to create the temperature maps. This novel approach in temperature modeling for injectors has demonstrated remarkable capabilities, offering good reproducibility of physical aspects and significantly reduced computation time. A spatial and temporal comparison between the evolution of the temperature in dual fuel mode and conventional diesel mode shows the influence of the combustion mode on the injector temperature. This difference is particularly apparent in the injector tip, which is 255 K hotter in dual fuel mode at full load.