Development of the Tier 1 Emission Reduction Control Strategy for GE-7FDL High-Power Medium-Speed Locomotive Diesel Engine

This paper summarizes the technical development of the GE-7FDL series locomotive diesel engine to EPA Tier 1 emissions standards. The goal of the project was to use the existing GE-7FDL Tier 0 engine with minimal design changes and optimize for performance with respect to the Tier 1 limits. The work focused on statistically quantifying the variation seen under standard test conditions, quantifying the impact of cooling system performance, altitude, and ambient temperature on exhaust emissions and fuel consumption, and developing a robust design and control strategy to ensure optimal emissions and fuel consumption throughout the operating range and life of the locomotive. A Tier 1 prototype locomotive was used during the development to characterize the performance trends of the engine. Testing was performed over the range of altitudes required by the EPA and advanced analysis techniques were used to develop control algorithms that meet Tier 1 emissions requirements and exceed fuel consumption commitments. Extensive verification/validation testing was performed to ensure that the design goals and process capability requirements were met.