摘要: |
In the next several years, the NCDOT Rail Division will add locomotives to the fleet it provides for the Amtrak-operated Piedmont passenger rail service between Raleigh and Charlotte. NCDOT is taking a leadership role in demonstrating new retrofit Blended After-Treatment System (BATS) emission controls for both existing and newly added locomotives. These emission controls are based on selective
catalytic reduction (SCR) for control of nitrogen oxides (NOx) emissions and diesel particle filters for control of particulate matter emissions. NOx and PM are harmful to public health and are regulated with respect to emissions and air quality. The effectiveness of these controls will depend on actual passenger rail service for actual duty cycles on the Piedmont route. Furthermore, SCR effectiveness may depend on exhaust temperature, which varies depending on engine load, and the durability of both SCR and DPF under retrofit conditions for a diesel locomotive has not been quantified. The research will include the following tasks: (1) development of a detailed measurement plan for rail yard and over-the-road measurements, using portable emission measurement systems, to quantify the activity, energy use, and emissions of each locomotive with the retrofitted BATS; (2) rail yard measurements to assess performance of the retrofitted BATS, especially with respect to emissions
reduction and impacts on energy operation that affect energy use; (3) over-the-road measurements for the same purposes of assessing the performance of the retrofitted BATS, especially with respect to emissions reduction and impacts on operation that affect energy use; and (4) update of a planning-level model for
estimating the energy use and emissions of a typical Piedmont train. The model will be based on secondby- second (1 Hz) speed, acceleration, rail grade, and rail curvature. The model will enable calculation of differences in energy use and emissions based on the use of BATS-retrofitted locomotives, biofuels,
operational strategies, and changes in the corridor (e.g., replacing a grade crossing with grade separation). These tasks will be done based on fuels specified by NCDOT, which are expected to include ultra low sulfur diesel (ULSD) as a baseline and a biodiesel blend such as B20. This project will support increased operational efficiency by providing an empirical data-driven basis for fuel choice and qualification of the Blended After-Treatment Systems on multiple locomotives,
by quantifying the consistency of the BATS performance when comparing locomotives, and by updating a planning tool to help evaluate and prioritize adoption of emission controls, fuels, and capital improvements to the rail corridor and to identify opportunities for improved operational practices (such as modifying train duty cycles to reduce energy use and emissions). Reductions in energy use lead to
operational cost savings. Sustained durable long-term reductions in emissions will help NCDOT apply for additional Federal grants to further reduce emissions by extending BATS retrofits and other emission reduction measures to additional locomotives in the fleet. The updated planning level model for train operations will help evaluate the operational implications of broader deployment of BATS. The field
measurements of the environmental performance of NCDOT equipment will be helpful for environmental planning, to inform regulatory issues, and for communication of the effectiveness of NCDOT emission reductions to the public and other stakeholders. NCDOT will use the results of this research to make decisions regarding selection of fuels, qualification of emission controls, priorities for capital improvements, and opportunities for improved energy efficiency. The research results will quantify the real-world effect of fuels and emission control technologies on locomotive energy use and emissions from which a decision will be made regarding fuel selection and retrofits for additional locomotives for ongoing train operations. The research results will enable NCDOT to independently assess the real-world performance of exhaust after-treatment systems to determine vendor compliance with contract requirements and to quantify the real world benefits of the
new technology. The results will enable NCDOT to evaluate the effect of emissions controls, fuels, operational improvements, and corridor improvements on energy and emission operational impacts. |