Cummins Inc. last week revealed the latest generation of the QSL9 engine at ConExpo, which is capable of meeting near-zero emissions levels. This 9-liter engine achieves 2014 EPA Tier-4 Final and EU Stage IV standards with an ultra-clean aftertreatment system, combining the Cummins Compact Catalyst with Selective Catalytic Reduction.
With up to 400-hp output, the QSL9 is designed to retain the higher output and faster engine response demonstrated by the Tier-4 Interim QSL9. Fuel efficiency at Tier 4 Final will be further improved over that achieved for the Tier 4 Interim engine.
The CCC-SCR ultra-clean aftertreatment system is specifically configured to provide a more compact and flexible equipment installation for Tier 4 Final. The Cummins Compact Catalyst, previously used for ratings below 174 hp, is scaled-up in size for the 9-liter platform. Combined with SCR, the aftertreatment system achieves near-zero emissions with fully passive, flow-through operation.
In addition to the QSL9, the CCC-SCR system will be utilized by the QSB6.7, QSB4.5 and QSB3.3 engines to offer a common aftertreatment solution from 75 hp to 400 hp. The scalability of the CCC-SCR system enables sizing to be configured for specific power outputs across the 3.3-liter to 9-liter engine range.
"We listened to equipment manufacturers before developing our Tier 4 Final architecture for the QSB3.3 to QSL9 product line, and the clear message we heard was to focus on reducing installation complexity as much as possible — while also retaining the high power output and performance offered by our Tier 4 Interim products," said Jeff Weikert, vice president - Cummins MidRange Engineering.
"I am very pleased to say that with the CCC-SCR ultra-clean aftertreatment system, we are able to meet and exceed our customer expectations for Tier 4 Final. With the addition of SCR, we now have the ability to precisely balance NOx reduction between aftertreatment and cooled Exhaust Gas Recirculation on the engine - giving us more control over the combustion formula than ever before.”
To meet Tier 4 Final in 2014, particulate matter reduces to 0.02 g/kW- hr and oxides of nitrogen reduce to 0.40 g/kW-hr. Compared to Tier-3 emissions levels, this represents a 90-percent reduction for both PM and NOx.
The SCR system developed by Cummins for Tier 4 Final is a next-generation design that moves beyond the SCR technology currently in use for Tier 4 Interim. The system incorporates a copper zeolite-based catalyst capable of up to 95 percent NOx conversion and able to operate more efficiently at lower temperatures. The system features advanced sensors to provide full closed-loop control. Diesel Exhaust Fluid dosing levels are minimized with enhanced mixing in the decomposition pipe.
The CCC-SCR aftertreatment will be available in multiple configurations, including switchback, horizontal and vertical. Optimization work will continue to refine aftertreatment packaging and evaluate innovative solutions to further enhance installation flexibility.
Headquartered in Columbus, Ind., Cummins Inc., a global power leader, is a corporation of complementary business units that design, manufacture, distribute and service engines and related technologies, including fuel systems, controls, air handling, filtration, emission solutions and electrical power generation systems. For more information, visit cumminsengines.com.
