ABSTRACT
Use of a driven turbocharger on a commercial diesel engine allows for direct control over the speed of the turbomachinery. Directly controlling the turbomachinery speed makes it possible to supply the necessary charge air independent of the energy available in the exhaust for the turbine to collect. This ability removes some of the constraints that exist in conventional turbochargers and allows for better optimization of emissions and efficiency during transient conditions as well as steady state conditions.
OEM testing of the SuperTurbo has shown that improvements in efficiency and emissions are possible. Driven turbos can carefully balance PM, NOx, EGR and AFR. Results show that driven turbochargers can balance NOx and PM and BSFC through engine transients with direct control of the speed of the turbomachinery. Precise control over AFR at all times, coupled with turbo-compounding from the driven turbocharger combine to improve engine efficiency. The use of a driven turbocharger allows additional turbine and compressor design freedom and many system enabling effects not typically possible with traditional turbochargers.
Actual engine OEM test data in this paper will demonstrate how driven turbochargers can be applied in the commercial diesel engine industry to help meet current and future emission regulations and efficiency targets. Test data from internal, third party, and customer test cells is presented to support claims.
