Engine Performances With Advanced Common Rail Injector Design

Abstract

This paper presents the application of the Ganser CRS common rail injectors with the proprietary poppet valve, the state of the art hydraulic switching device for common rail injectors. Due to its unique design, the combustion process is optimized by stable and rapid injection rate profiles, which are allowing for reliable multiple injection driving strategies to further reduce the fuel consumption and in-cylinder emissions. Due to its flexible characteristics, the poppet valve is applicable in numerous fields. Two applications are specifically presented in this paper. The first application of the poppet valve is the common rail retrofit of a V16 GE® 7FDL locomotive engine with a power output of 4000HP. In this retrofit project, the existing mechanical fuel injection system is replaced by a common rail system. The injector design is such that no changes to the cylinder head are required. The injector includes an integrated accumulator for maximized and constant injection pressures during the whole injection process. Each cylinder bank is equipped with its own slim rail attached to the engine structure and a dedicated high pressure pump, allowing for a freely configurable injection event up to 1600bar. The resulting significant reduction of fuel consumption over the locomotive duty cycle as well as emissions reductions are discussed in detail in this paper. The poppet valve is also successfully applied in the field of micro pilot injection for new dual fuel engines, in the marine and power-gen sectors, as a second application of this injector design principle. On these engines, the micro pilot injection quantity to ignite the gas is typically 0.5–2% of the total energy input. This maximized diesel fuel substitution is possible because of the accurate switching characteristics of the poppet valve at smallest injection quantities. With the application of the proprietary Wave Dynamics and Dampening System (WDD) [1] and injector-integrated accumulators, the rail can be replaced completely by so-called jumper lines, while maintaining a slim outer shape on the overall injector size.