Steven G. Fritz

Fuel Consumption and Exhaust Emissions From a 1,125 kW Multiple Genset Switcher Locomotive

Conventional switcher or shunting locomotives in North America are powered by a single Electro-Motive Diesel (EMD) 12 or 16 cylinder 645E engine which operate at eight distinct power levels, plus idle, at engine speeds ranging from 250 to 900 rpm, and power ratings of 1125 to 1500 kW. The individual power (notch) settings are weighted according to an established duty cycle to obtain overall fuel consumption and exhaust emission rates. Recently introduced locomotive power systems utilize multiple smaller displacement non-road diesel engines packaged as individual generator sets to obtain a cleaner and more efficient locomotive. This paper compares exhaust emissions and fuel consumption from a conventional switcher locomotive with a single large displacement engine to that of a repowered locomotive utilizing three 345 kW generators.Copyright

Exhaust Emissions From a 1,500 kW EMD 16-645-E Locomotive Diesel Engine Using Several Ultra-Low Sulfur Diesel Fuels

This paper documents results from an experimental study performed to determine the effects of several ultra-low sulfur diesel (ULSD) fuels (< 15 ppm S) on exhaust emissions from a 1,500 kW EMD 16-645-E, roots-blown, diesel locomotive engine. U.S. EPA-regulated emission levels of hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx ), and particulate (PM) were measured using U.S. EPA locomotive test procedures while operating on four ULSD fuels, plus a fifth baseline fuel which was a commercially-available Federal on-highway diesel fuel (< 500 ppm). The four ULSD fuels were (1) a ULSD California motor vehicle diesel fuel (CARB fuel) with an aromatic content of less than 10 percent, (2) a ULSD “equivalent” California motor vehicle diesel fuel with an aromatic content of 24 percent, (3 and 4) two custom blended “2006 ULSD Federal” diesel fuels with relatively low Cetane Numbers and higher aromatic levels. This paper reports the changes observed in the regulated exhaust emission levels between the ULSD CARB diesel fuels and the ULSD Federal diesel fuels.Copyright

Locomotive Idle and Start-Up Exhaust Emissions Testing

The objective of this project was to quantify locomotive idle and start-up emissions, to answer the question: “At what point is it preferable from an emissions standpoint to idle a locomotive engine rather than shut down the engine and restart it when needed?” Idle and restart emissions tests were performed on two Tier 0 emission locomotives; a 1,120 kW EMD MP15-DC Switcher (UPY1378) and a 3,280 kW line-haul GE Dash9-44CW (BNSF4373). The results of the testing showed that continuous idling emissions of NOx and PM were greater than the start up emissions from the two test locomotives. The only exception was the 15-minute restart on the line haul locomotive BNSF4373, but this was envisioned to be due to a non-typical operational cycle of the GE AESS. The results of the extended idle tests showed that the older locomotive (UPY1378) operates at a relatively consistent idle emissions output through the four hours of extended idle. However, idle emissions from BNSF4373 varied over the idle period as the engine speed changes in response to on-board computer controls to accomplish engine warm-up and a series of other locomotive functions.Copyright

Particle size distribution and mass emissions from a mining diesel engine equipped with a Dry system technologies emission control system

Particle size distribution, number, and mass emissions from the exhaust of a 92 kW 1999 Isuzu 6BG1 nonroad naturally aspirated diesel engine were measured. The engine exhaust was equipped with a Dry System Technologie® (DST) auxillary emission control device that included an oxidation catalyst, a heat exchanger, and a disposable paper particulate filter. Particle measurement was taken during the ISO 8178 8-mode test for engine out and engine with the DST using a scanning mobility particle sizer (SMPS) in parallel to the standard filter method (SFM), specified in 40 CFR, Part 89. The DST efficiency of removing particles was about 99.9 percent based on particle number, 99.99 percent based on particle mass derived from number and size. However, the efficiency based on mass derived from the SFM was much lower on the order of 90 to 93 percent. This discrepancy in particle mass efficiency between the two methods was mainly due to poor correlation between the mass derived from number and size and the mass measured using the SFM. This poor correlation was obtained for the DST out particulate matter (PM) emission and not for engine out. For DST out PM, the SFM tends to exaggerate the mass emissions of particles due to the condensation/adsorption of gas phase non aerosol volatile compounds on the PalflexT60A20 filters used for particle mass measurement, thus resulting in a lower efficiency of particle removal. If the health effect of particles is due to the mass and number of their physical characteristics, particle measurement using the SFM may need rethinking, particularly if the nature of the measured product is dominated by volatile rather than soot.

Locomotive emissions measurements for various blends of biodiesel fuel.

The objective of this project was to assess the effects of various blends of biodiesel on locomotive engine exhaust emissions. The emission tests were conducted on two locomotive models, a Tier 2 EMD SD70ACe and a Tier 1 Plus GE Dash9-44CW, using two baseline fuels: (1) conventional Environmental Protection Agency (EPA) ASTM No. 2-D S15 certification diesel fuel and (2) commercially available California Air Resource Board (CARB) Ultra Low Sulfur Diesel (ULSD) fuel. A single batch of soy-based B100 was mixed in with the EPA and CARB diesel to yield a 5 percent and 20 percent blend of fuel. A randomized test matrix was used to perform triplicate tests on each of the six test fuels (EPA0, CARB0, EPA5, CARB5, EPA20, and CARB20). General emissions and fuel economy trends seen in other studies and applications for biodiesel use were also observed in this study. Higher blend levels of biodiesel were associated with lower carbon monoxide and particulate matter, as well as with higher levels of nitrogen oxides and fuel consumption. Use of diesel fuel with 20 percent biodiesel often resulted in statistically significant differences from the fuel with 0 percent or 5 percent biodiesel, while the difference between 0 percent and 5 percent biodiesel was generally not statistically significant.

PR30C-LE Locomotive With DOC and Urea Based SCR: Field Trial and Emissions Testing After 1,500 and 3,000 Hours of Operation

This paper details part two of the demonstration of a 2,240 kW (3,005 HP) PR30C-LE locomotive with exhaust aftertreatment containing diesel oxidation catalysts (DOC) and urea-based selective catalytic reduction (SCR). The PR30C-LE is a remanufactured and repowered, six-axle, diesel-electric, line-haul locomotive. Program objectives were to measure emission levels of the locomotive and record locomotive and aftertreatment operations during a 12 month revenue service field trial. Phase 1 of the program involved engine baseline emissions testing as well as emissions testing with the aftertreatment at the beginning of its useful life, or the 0-hour condition. Results from Phase 1 showed engine-out emission levels were within U.S. EPA Locomotive Tier 2 limits. With aftertreatment at beginning of useful life, hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) were below Tier 4 limits, and particulate matter (PM) was below Tier 3 limits.Phase 2 consisted of a 12 month revenue service field trial and additional emissions testing completed at the midpoint and end of the field trial. On-board GPS data, aftertreatment NOx sensor data, and various locomotive operating parameters were logged continuously during the field trial. The field trial data suggests the impact SCR technology has on locomotive NOx emissions is driven primarily by locomotive utilization and loading factor. Overall the field trial included 3,082 hours of operation and PRLX3004 generated approximately 572 MW-hours of work over the 12 month period. Emission test results at the 1,500-hour and 3,000-hour conditions showed very little change from 0-hour test results. Emission levels remained below Tier 4 limits for HC, CO, and NOx, and below the Tier 3 limit for PM. Phase 2 test results suggest there was no significant degradation in emissions performance during the field trial, and no major issues with the locomotive and aftertreatment were detected. In total there are currently five PR30C-LE locomotives in operation within California and Arizona. Together they have completed a cumulative 30,800 hours of revenue service through June 2012 without report of a major issue.Copyright

Locomotive Exhaust Temperatures During High Altitude Tunnel Operation in Donner Pass

Locomotives in heavy-haul service at high altitude and within unventilated tunnels operate under some of the most extreme conditions encountered in the U.S. with regard to high ambient temperatures and high locomotive exhaust temperatures. Consideration of such conditions is crucial to the design of future catalytic emission control systems for locomotives. Field testing was conducted on two locomotives certified to U.S. Federal Tier 2 locomotive emissions standards operating as part of a four-locomotive consist pulling a heavy-freight train west-bound through the Donner Pass Region in late August 2007. The highest post-turbine exhaust temperatures observed over the entire test route occurred within Union Pacific Tunnel 41 — an approximately two-mile-long, unventilated tunnel located near Norden, California. Engine protection measures within the electronic locomotive and engine management systems of both locomotives limited the peak exhaust temperatures encountered during the tests to less than 560°C.Copyright

Exhaust Emissions From a 2,850 kW EMD SD60M Locomotive Equipped With a Diesel Oxidation Catalyst

This paper describes the test results of a program to apply an experimental diesel oxidation catalyst (DOC) to a 2,850 kW freight locomotive. Locomotive emissions and fuel consumption measurements were performed on an Electro-Motive Diesel (EMD) model SD60M locomotive, owned by Union Pacific Railroad company, that had been recently rebuilt to EPA Tier 0 exhaust emission certification levels. Emission testing was performed at the Southwest Research Institute (SwRI) Locomotive Exhaust Emissions Test Center in San Antonio, Texas. US EPA-regulated emission levels of hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx ), and participate (PM) were measured using U.S. EPA locomotive certification test procedures in three configurations; first a baseline with a relatively high sulfur diesel fuel (2,913 ppm sulfur) meeting EPA locomotive certification test specifications, and another baseline using ultra-low sulfur diesel fuel (ULDS), and finally a test using ULSD after the installation of a diesel oxidation catalyst designed and manufactured by MIRATECH Corporation (patent pending). The DOC was applied pre-turbine, within the exhaust manifold due to both space and exhaust temperature considerations. This paper describes the design of the DOC-equipped exhaust manifold, and reports the changes in the regulated exhaust emission levels between the baseline tests and after installation of the DOC. Also described is a locomotive on-board monitoring system used to monitor DOC performance during ongoing revenue service field testing.Copyright

Partial Flow DPF System for Large Bore or High Power Applications

A number of technical challenges are faced when applying wall flow Diesel Particulate Filter (DPF) systems to large high horsepower off-highway applications, locomotives, and marine diesel engine applications due to the size of the DPF system required and the space constraints associated with these applications. Experimental results show that a new approach of adding an exhaust bypass valve, creating a partial-flow DPF system, can greatly reduce the DPF package size while continuing to offer significant PM emission reductions. The exhaust bypass valve is configured to open proportionally to maintain a pre-set maximum engine backpressure as the exhaust flow increases.Proof-of-concept testing of an experimental partial flow DPF system was conducted on a 3MW, 4-stroke locomotive engine, following U.S. EPA locomotive certification test protocols. These tests showed that the experimental DPF system, which was approximately 40 percent smaller than what would be expected for this application, provided an 84 percent PM reduction over the US-EPA Switcher Cycle and 59 percent reduction over the Line-Haul Cycle. It was calculated that the system could provide a 91 percent PM reduction over the Switcher Cycle and 76 percent PM reduction over the Line-Haul Cycle with addition of a DOC in the bypass exhaust flow.Copyright

PR30C-LE Locomotive With DOC and Urea Based SCR: Baseline and Initial Aftertreatment Emissions Testing

The PR30C-LE is a repowered six-axle, 2,240 kW (3,005 hp), line-haul locomotive that was introduced to the rail industry in 2009. The Caterpillar 3516C-HD Tier 2 engine is equipped with an exhaust aftertreatment module containing selective catalyst reduction (SCR) and diesel oxidation catalyst (DOC) technology. PR30C-LE exhaust emission testing was performed on test locomotive PRLX3004. Phase-1 of the test program included the following tasks: engine-out baseline emissions testing without the aftertreatment module installed, aftertreatment module installation, commissioning and degreening, and emissions testing with the aftertreatment. Emission results from testing without the aftertreatment module, referred to as the baseline configuration, indicated that PRLX3004 emissions were below Tier 2 EPA locomotive limits without aftertreatment. Emission test results with the DOC and SCR aftertreatment module showed a reduction in nitrogen oxides (NOx) of 80 percent over the line-haul cycle, and 59 percent over the switcher cycle. Particulate matter (PM) was reduced by 43 percent over the line-haul cycle and 64 percent over the switcher cycle. Line-haul cycle composite emissions of Hydrocarbon (HC) and carbon monoxide (CO) were reduced by 93 and 72 percent, respectively. The PR30C-LE locomotive achieved Tier 4 line-haul NOx, CO, HC, as well as Tier 3 PM levels. There are currently five PR30C-LE locomotives in operation in California and Arizona, and the total hour accumulation of the five PR30C-LE locomotives as of October 2011 was 20,000 hours.Copyright