Ultra-High Efficiency Serial TwoStage Turbocharging System for Maximum Engine Efficiency
Honeywell Transportation Systems has collaborated on an ultra-high efficiency two stage serial turbocharger system under the European Union FP7 GA-2012 CORE project. The compressors of both the low pressure and high pressure turbochargers were design optimized for the highly specific operating conditions of two stage boosting. The high pressure turbine is characterized by a sector divided fixed vane nozzle, while the low pressure turbine stage features an axial turbine wheel. The two turbines were designed specifically to achieve highest possible efficiency while minimizing ducting losses between the two stages. The end result is a novel high performance boosting system that fits in a unique package. This paper describes the approach used to set design targets for each stage of the two stage turbocharger system. The design approach used to meet these targets will be presented, and test results from gas stand will be shown measured against performance targets and performance predictions.