Cummins Inc. on Friday, Nov. 16, announced its technology path to meet stringent U.S. Environmental Protection Agency Tier 4 Interim and European Stage IIIB mobile off-highway emissions standards across the 174-hp to 751-hp (130-560 kW) powerband, which take effect in 2011.
Core technology will be Cummins Particulate Filter and cooled Exhaust Gas Recirculation (EGR) as part of an integrated technology solution extending from air intake to exhaust aftertreatment. Engine enhancements also will include the use of Cummins Variable Geometry Turbochargers (VG Turbo), advanced electronic controls and High Pressure Common Rail fuel systems.
Common Tier 4 subsystem architecture will extend from the MidRange QSB to the Heavy-Duty QSX engines. The Cummins Tier 4 product range will maintain or increase power outputs compared to Tier 3, the company says, while fuel efficiency will be improved by up to 5 percent, dependent on rating and duty cycle.
“Our Tier 4 solution is driven by the need to deliver the lowest cost of ownership and most productive power solutions for operators,” says Ric Kleine, vice president of off-highway business for Columbus, Ind.-based Cummins. “Cummins’ long-term investment in the design and manufacturing of key component technology provides a significant advantage for our Tier 4 solution. We were able to take the proven durability of our Tier 3 base engines and combine this with successful technologies, such as cooled EGR, we have leveraged from Cummins’ broad experience.”
While exhaust aftertreatment may be new technology for the off-highway industry, it is not new to Cummins, Kleine says. “Our Cummins Emission Solutions business is one of the world’s leading manufacturers of this key component technology,” Kleine says. “For Tier 4 applications of the Cummins Particulate Filter, we are factoring in off-highway requirements such as high-shock loads, angularity, space restrictions and working environment conditions.”
Cummins says it achieved Tier 4 Interim emissions levels by developing the engine combustion recipe to work with the aftertreatment filter in reducing particulate matter (PM) emissions levels by 90 percent; the use of cooled EGR enables the required 45 percent reduction in oxides of nitrogen (NOx) to be achieved.
Cummins says its cooled EGR is an engine-integrated subsystem that has proven to be highly effective working in tandem with Cummins VG Turbo; this provides superior engine response with optimized boost at given exhaust gas recirculation rates and engine speeds. Cummins says clean engine credentials will be enhanced further with a company-designed crankcase filter that eliminates escaping blowby gases, oil mist and droplets.