The NCDOT Rail Division operates passenger train service between Raleigh and Charlotte. NCDOT has rebuilt six locomotives in the least two years, including locomotive numbers NC 1755, and NC 1797, NC 1810, NC 1859, NC 1869, and NC 1893. The NC 1700 series locomotives are F59PHIs. The NC 1800 series locomotive are F59PHs. As part of the rebuilds, the head end power (HEP) engine of each locomotive was replaced with a CAT A18 ACERT engine of approximately 900 hp. These engines provide shaft power to an alternating current generator, which in turn provides electrical power for the consist of passenger rail cars. This electrical power is used for lighting and space conditioning in the cars. NCDOT would like to quantify the emission rates of these HEP engines so that they can be compared to the emission limits of applicable non-road engine regulations from the U.S. Environmental Protection Agency. The purpose of the comparison is to determine whether the engines have emission rates less than, comparable to, or greater than the standard. However, the goal is not to conduct an official certification test. The latter would require removing the engines and testing them with an engine dynamometer. Rather, the goal here is to measure the emissions in the NCDOT Raleigh Capital Rail yard using Portable Emissions Measurement Systems. In previous work, NCSU has conducted measurements of HEP engines at low loads by connecting passenger cars and operating their lighting and space conditioning. However, to measure emissions at loads comparable to those used in emissions measurements, the engine load must be higher than can be achieved by connecting a consist of passenger cars. Therefore, NCDOT will lease a ‘load box’ that can accept the electrical output of the A18 engine-generator at up to 100% load.
The primary objectives of this study are to:
- Demonstrate a methodology for using a Portable Emissions Measurement System (PEMS) to obtain emission factors at various loads for the HEP engines;
- Establish baseline performance of the HEP engines that can be used for comparative purposes in future assessments; and
- Provide insight regarding whether the HEP engines are compliant with the applicable emission standard.
This project will include the following tasks: (1) rail yard measurement of emission rates on the HEP engines using ultra low sulfur diesel (ULSD) fuel at a wide variety of load settings from idle to 100% load; (2) measurement of some of the HEP engines using a biodiesel blend; (3) evaluation of whether the HEP engines are compliant with applicable standards; and (4) estimation of emission rates typical of previously observed electrical load for passenger car consists.
The results of this project will enable the Rail Division to accurately assess the emissions benefits of the locomotive rebuilds. These data can be used to identify priorities for further emission reductions measures, if needed, and to claim credit for the energy and environmental benefits of rail transportation. These data and information will be useful to the Rail Division as the basis for prioritizing future activity pertaining to asset management and community relations. Furthermore, the data measured here, combined with measurements of the locomotive prime mover engines in previous work, will be useful for quantifying emission rates of key pollutants (i.e. NOx, CO, HC, PM, and CO2) per passenger mile, to assess the environmental benefits of rail travel versus use of a personal automobile, and for long term planning purposes.
