Turbocharger with Variable Compressor Geometry - Another Contribution to Improved Fuel Economy by the Boosting System

摘要

The emission legislation connected with new engine boundary conditions leads to increased demands to the boosting system. Especially for the compressor stage wider maps with increased efficiency close to the surge line are needed. To solve the typical trade-off between a stable surge line and rated power performance, BorgWarner developed a turbocharger with variable compressor geometry. This paper presents the steps from the concept choice with test results and detailed potential studies over a tested prototype design to a value proposition in combination with a Miller engine. The efficiency improvement by the variable compressor along with an optimized turbocharger is an enabler for RDE relevant engine measures. Together with a very package friendly design solution BorgWarner's variable compressor geometry will set a new milestone in boosting technology.