Turbocharger Power for Future Railway Applications

The design requirements of exhaust gas turbochargers for diesel locomotive applications are becoming more stringent. Some of the major drivers are meeting emission regulations and power demands, whilst maintaining the required levels of reliability and serviceability. These increasingly demanding requirements are significantly impacting the design of modern diesel-electric locomotives. In order to achieve these sometimes conflicting requirements, appropriate technology needs to be employed to both the engine and turbocharger design. Given that there are a number of possibilities one has with the engine design, including fuel injection timing and equipment, valve timing, compression ratio etc., this paper will focus on turbocharging and the development cycle of ABB Turbo Systems Ltd. new TPR61 locomotive turbocharger. Starting with the demanding operating environment for locomotive turbochargers and market and regulatory requirements (increasing power, efficiency and reliability — decreasing emissions and bsfc), the impact these have on turbocharger design will be shown. Based on proven ABB technology, the TPR61 is a special derivative, targeted for turbocharging locomotive diesel engines with ratings of up to 4000 hp per turbocharger or over 6000 hp locomotives with a twin turbocharger solution. For future requirements, the compressor stage development potential and also Variable Turbine Geometry (VTG) will be discussed, how it can be applied and the benefits it can bring to locomotive applications of the future.