Cummins Inc. has begun development of a 15-liter heavy-duty, spark-ignited natural gas engine to meet demand for on-highway applications. As natural gas production grows in North America and the fuel becomes more readily available, Cummins believes that there is a strong market for engines powered by an alternative to diesel fuel.
Cummins has been investing significantly in the development of natural gas engines. In addition to its off-highway natural gas engines, Cummins is already producing on-highway spark-ignited natural gas engines for Cummins Westport, its joint venture with Westport Innovations in Vancouver, British Columbia. Engines offered by Cummins Westport range in size from 5.9 liters to the recently announced 12-liter ISX12 G, which will begin production in 2013. (Earlier post.)
The ISX15 G will be based on the ISX15 diesel engine and will build on Cummins technology with spark-ignited, stoichiometric cooled exhaust gas recirculation (SEGR) technology, first introduced on the 8.9 liter ISL G and also being applied in the ISX12 G.
The cooled EGR system takes a measured quantity of exhaust gas and passes it through a cooler to reduce temperatures before mixing it with fuel and the incoming air charge to the cylinder. Cooled EGR, in combination with stoichiometric combustion provides significant benefits.
The use of cooled EGR (in place of large amounts of excess air used in lean burn technology) lowers combustion temperatures and knock tendency. SEGR combustion also improves power density and fuel economy vs. lean burn and traditional stoichiometric engines. Compared to previous Cummins Westport (CWI) lean burn natural gas engines, ISL G torque at idle is improved more than 30% and fuel economy is improved by up to 5%.
A simple, maintenance-free Three-Way Catalyst will be the only required exhaust aftertreatment. The engine will run on compressed natural gas, liquefied natural gas or biomethane.
Cummins ISX15 G is expected to be in limited production by 2014.
EcoFit. At the Mid-America Trucking Show (MATS), Cummins Emission Solutions, a subsidiary of Cummins Inc., is showcasing its latest EcoFit emissions control technologies.
EcoFit Aftertreatment Solutions. New EcoFit aftertreatment solutions are being unveiled at MATS for the first time in the North American market. These solutions are designed to monitor, control and diagnose engine and aftertreatment systems in a way that reduces emissions while optimizing performance of the entire system. EcoFit products, available to all commercial vehicle engine manufacturers, will achieve a lower overall cost of ownership and allow customers to differentiate from the competition’s through improved vehicle integration.
EcoFit Urea Dosing System. The EcoFit Urea Dosing System (UDS) is being developed by Cummins Emission Solutions for use in light-, medium- and heavy-duty commercial vehicles. Initially announced last November, the EcoFit UDS is designed to meet upcoming regulations in China, India and Russia. Work is under way to apply the system to upcoming emissions regulations in other regions.
The EcoFit UDS delivers improved NOx conversion efficiency, which offers the opportunity to tune engines for improved fuel economy or to reduce the size of a typical SCR system. The air-assisted system is also designed to minimize the risk of urea deposits, increasing the durability and reliability of the aftertreatment system. Offered as both tank-mount and chassis-mount, the system reduces vehicle integration efforts.
EcoFit Hydrocarbon Dosing System. Cummins Emission Solutions will display its improved EcoFit Hydrocarbon Dosing System (HDS) at MATS. The EcoFit HDS enables thermal management for active Diesel Particulate Filter (DPF) regeneration. Offering improved reliability, the system uses a new design that improves robustness by decreasing the chances of clogs and leaks. Without changing the external design, regeneration capabilities remain efficient by reducing flow loss over time at similar flow rates as those of today.
EcoFit Catalyst Technology. Cummins Emission Solutions is continuously working on innovative catalyst technologies that make aftertreatment systems perform more efficiently and in smaller packages, offering improved fuel economy. One of the EcoFit Catalyst Technologies currently in development will be on display at MATS, illustrating the latest innovation in extruded SCR catalysts. Extruded SCR catalyst technology enables significant reduction in aftertreatment size, or the ability to increase NOx conversion rates within an SCR system.