LAS VEGAS (March 11, 2008) - Cummins Inc. (NYSE:CMI) revealed today the next-generation QSB6.7 engine with a fully integrated air intake to exhaust aftertreatment system ready to meet U.S. EPA Tier 4 Interim and European Stage IIIB off-highway emissions regulations in January 2011. The 6.7-liter QSB engine displayed at the CONEXPO-CON/AGG show is an installation-ready package incorporating the new Cummins Direct Flow air filtration system by Fleetguard and Cummins Particulate Filter exhaust aftertreatment.
Cummins clean diesel technology enables the Tier 4 QSB6.7 engine system to achieve a 90 percent reduction in Particulate Matter (PM) and a 45 percent reduction in Oxides of Nitrogen (NOx). While meeting these stringent emission levels, Cummins integration capability also enables the QSB6.7 to increase Tier 3 power output from 275 hp (205 kW) to a new top rating of 300 hp (224 kW) for Tier 4. This will take the QSB6.7 to a power output more typical of a larger displacement engine and offer a significant installation advantage.
"By making an early start with developing our Tier 4 emissions solution we have been able to optimize Cummins integrated technology and achieve higher power outputs and improve fuel efficiency," said Ric Kleine, Vice President of Cummins Off-Highway Business.
"Cummins ability to design, build and integrate a complete installation package from air intake to exhaust aftertreatment means we can deliver the most dependable solution with the lowest cost of ownership. For equipment manufacturers our integrated system approach will offer more efficient packaging for an easier Tier 4 installation," added Kleine.
Cleaner and more fuel-efficient in-cylinder combustion is achieved for Tier4 by utilizing cooled Exhaust Gas Recirculation (EGR) together with a High Pressure Common Rail (HPCR) fuel system. Cooled EGR works by re-circulating a varying proportion of the exhaust gas back to the cylinder. This reduces the oxygen content to a lower combustion temperature with a resulting 45 percent reduction in NOx formation. This combination of cooled EGR and HPCR fuel injection flexibility enables Tier 4 QSB6.7 fuel consumption to be reduced by up to 5 percent compared to Tier 3, dependent on engine rating and duty cycle.
Integrated Particulate Filter Aftertreatment
The Cummins Particulate Filter is part of an integrated engine and aftertreatment solution that reduces Particulate Matter (PM) emissions by 90 percent to meet the 2011 regulations. The PM is collected on the filter and oxidized gradually by catalytic passive regeneration to exit the filter as clean exhaust gas. Depending on duty cycle, PM accumulation rate may eventually exceed oxidation rate, and a short active regeneration is initiated by the engine electronic control module utilizing the HPCR fuel system and variable geometry turbocharger. Cummins in-house capability has been applied in developing core programs and algorithms for controlling the particulate filter through the engine electronic control module.
Cummins successfully utilized particulate filter technology to meet EPA'07 on-highway regulations in North America and has leveraged this experience to develop a particulate filter specifically tailored for off-highway operational factors. The filter replaces the muffler in the exhaust stream and provides equivalent noise reduction.
"The Cummins Particulate Filter for Tier 4 is an exceptionally rugged design which is hardened to withstand severe shock loads and vibration," said Susan Harrison, Executive Director, Cummins Industrial Engineering.
"A compact profile with flexible inlet and outlet orientations enable the Cummins Particulate Filter to integrate more effectively with varying types of equipment installations. Together with the Cummins Direct Flow air filtration system, the Particulate Filter aftertreatment combines the packaging integration for a complete air-in to exhaust-out installation for Tier 4 applications," added Harrison.
Cummins Tier 4 engine range will be available with a new type of air filtration system providing integrated management of the engine airflow. The Cummins Direct Flow air filtration system by Fleetguard provides a 35 percent smaller installation profile than typical Tier 3 air filtration systems, yet retains the same filtration efficiency. This is accomplished by creating a direct-flow path through the filter media which is packaged in a rectangular configuration rather than a conventional cylindrical shape. The Direct Flow housing includes a sensor to monitor temperature and pressure which sends data to the engine electronic control module to ensure optimum air intake system operation.
Cummins expertise in air filtration is also employed to prevent crankcase blowby gas escaping from the engine with a high-efficiency crankcase filter. The filter also eliminates oil mist and tiny oil droplets to maintain clean engine operating conditions.
Air handling on the Tier 4 QSB6.7 is significantly enhanced with a Cummins Variable Geometry Turbocharger replacing the wastegated turbocharger on the Tier 3 engine. Manufactured by Cummins Turbo Technologies, the sliding-nozzle design of the Variable Geometry Turbocharger improves engine response by continuously varying the airflow boost to precisely match engine rpm and load demands.
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. Headquartered in Columbus, Indiana (USA), Cummins serves customers in more than 160 countries through its network of 550 company-owned and independent distributor facilities and more than 5,000 dealer locations. Cummins reported net income of $739 million on sales of $13.05 billion in 2007.