Cummins and Tula collaboration demonstrate benefits of diesel Dynamic Skip Fire in reducing tailpipe NOx emissions
Cummins Inc. and Tula Technology, Inc., a tech leader in improving propulsion efficiency and reducing emissions in passenger cars, announced their collaboration on a significant technical demonstration of diesel Dynamic Skip Fire (dDSF™). By using dDSF software to control cylinder deactivation, Cummins and Tula have demonstrated significant reductions in emissions and fuel consumption.
“At Cummins, it’s our mission to power a more prosperous world. We do this by helping customers succeed through innovative and dependable products that are good for the customer and the environment. We will continue to innovate the diesel engine system to make it lighter, more reliable, powerful and fuel-efficient, and we are encouraged by the progress demonstrated in this collaboration and what it could mean for future diesel technology,” said Lisa Farrell, director, Advanced System Integration, Cummins Inc.
The project started in early 2019 with the goal of optimizing cylinder deactivation strategies for diesel engines, which could result in emission reduction benefits. Advancements through the project are expected to help address future, more stringent NOx regulations.
The collaboration work was carried out on a Cummins X15 Efficiency Series 6-cylinder diesel engine, which offers class-leading fuel economy. The joint development team modified the engine system to integrate and leverage Tula’s Dynamic Skip Fire (DSF®) control algorithms to command combustion or deactivation on a cylinder event basis. On the challenging low-load cycle being proposed by the California Air Resources Board, modeling of dDSF technology predicted reductions in tailpipe NOx (oxides of nitrogen) emissions while simultaneously reducing CO2 (carbon dioxide).
“We have some good initial test results and we’re moving into the vehicle testing and cycle testing phase,” Farrell said.
The reduction of tailpipe NOx is achieved primarily by optimized exhaust temperature control, resulting in dramatically improved conversion efficiency of the aftertreatment system. The technology achieves CO2 reductions through improvements in combustion and reductions in pumping work. Further, dDSF delivers improved tailpipe emissions while simultaneously reducing fuel consumption, allowing for further optimization of these critical parameters.
“Our partnership with Cummins has given us the opportunity to expand our DSF technology beyond its success in gasoline engines. Demonstrating the capability to improve fuel efficiency while also achieving very effective emissions control is extremely important for all diesel engine applications in the future,” said R. Scott Bailey, president and CEO of Tula Technology.
Cummins and Tula have released their joint paper “Diesel Dynamic Skip Fire (dDSF®): Simultaneous CO2 and NOx Reduction” for the 2020 Vienna Motor Symposium, which presented and quantified the success of dDSF in increasing efficiency and reducing CO2 and NOx. The paper reflected the successful partnership and collaboration between Cummins and Tula in evaluating dDSF for the diesel market. The collaboration will continue with exploring future system optimization and viability to control noise, vibration and harshness in commercial vehicle applications.