1. Exhaust Gas Recirculation (EGR): EGR systems reduce the formation of nitrogen oxides (NOx) emissions by recirculating a portion of the exhaust gas back into the engine. The cooled exhaust gas mixes with the fresh air-fuel mixture, lowering the combustion temperature and inhibiting NOx formation.
2. Diesel Particulate Filters (DPFs): DPFs capture and trap soot particles from the exhaust stream. Through periodic regeneration processes, the accumulated soot is burned off, ensuring particulate matter (PM) emission compliance.
3. Diesel Oxidation Catalysts (DOCs): DOCs are installed in the exhaust system to promote chemical reactions that convert harmful pollutants, such as carbon monoxide (CO) and hydrocarbons (HC), into less harmful components like carbon dioxide (CO2) and water vapor.
4. Selective Catalytic Reduction (SCR): SCR systems further reduce NOx emissions by injecting a urea-based solution (Diesel Exhaust Fluid, DEF) into the exhaust stream. The DEF reacts with NOx in the presence of a catalyst, converting them into harmless nitrogen and water.
5. Advanced Fuel Injection Systems: Precise fuel injection technology improves combustion efficiency and reduces emissions. Common-rail fuel systems, high-pressure injectors, and multiple injection events ensure optimal fuel atomization and efficient fuel burn.
6. Engine Control Modules (ECMs): Advanced electronic control systems monitor and adjust engine parameters based on operating conditions. ECMs optimize fuel delivery, EGR rates, and aftertreatment system operation to minimize emissions.
7. Low-Friction Components: Incorporating low-friction components, such as ceramic-coated pistons and roller bearings, reduces fuel consumption and, as a result, lowers emissions.
8. Aerodynamic Design: Improvements in engine and component design, such as optimized air intake and exhaust systems, enhance airflow and improve engine efficiency, leading to reduced emissions.
By integrating these technologies and adopting advanced engineering practices, Cummins highway engines achieve compliance with stringent emission standards while delivering reliable performance and fuel efficiency. Continuous research and development efforts enable Cummins to meet evolving emission requirements and contribute to sustainable transportation.
