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Jacobs and Tula to cooperate on cylinder deactivation technology

17 September 2021

Jacobs Vehicle Systems and Tula Technology have signed a cooperation agreement to accelerate the development of Jacobs Cylinder Deactivation® (CDA®) valve actuation technology in conjunction with Tula’s Dynamic Skip Fire (DSF®) control algorithms. The agreement builds on two years of R&D collaboration between the two companies to reduce NOx and CO2 emissions from medium and heavy-duty vehicles.

Jacobs CDA hardware and Tula’s diesel DSF (dDSF) achieve greater emission reductions when combined, the companies said. The agreement will allow technical development to expand the operating range at which emissions reductions can be achieved when the two technologies are combined. Jacobs and Tula also will explore opportunities for reduced NOx and CO2 emissions in off-road vehicles and equip a Class 8 demonstrator truck with both Jacobs’ CDA and Tula’s diesel DSF technologies.

“While CDA and dDSF are available to commercial powertrain manufacturers as separate systems, our experience indicates that integrating the two technologies delivers much greater benefit to today’s medium- and heavy-duty engines,” said Steve Ernest, vice president of engineering and business development at Jacobs Vehicle Systems. “We have been working with Tula for several years, and this formal agreement solidifies our relationship as we demonstrate the benefits of using CDA and dDSF in tandem.”

While cylinder deactivation has been commercially applied to Otto cycle engines for several decades to reduce throttling losses, its use in diesel engines has been very limited. As diesel engines are unthrottled, benefits have been more challenging to realize.

However, with continued efforts to further reduced diesel NOx emissions, the need to manage exhaust temperatures after a cold start and under low load conditions to ensure that NOx reduction catalysts remain active has become more critical. Conventional thermal management techniques such as retarded combustion phasing and fuel dosing over a DOC increase the fuel consumption penalty. Cylinder deactivation, often combined with other engine measures, can achieve the required exhaust temperature at low load conditions while keeping the fuel consumption penalty at a minimum.

Source: Jacobs