As the exhaust gas aftertreatment strategies are defined by the OEMs, it is part of our system competence to ensure that the individual components can be applied with a maximum amount of flexibility.

—Wolfgang Gutbrod, Head of the commercial vehicles customer segment within the Continental Business Unit Engine Systems, Powertrain Division

In the case of the EMS3 engine management this is an intrinsic benefit of the open system architecture. As far as the components are concerned, the options range from supplying individual actuators and sensors up to complete system concepts, contributed by EMITEC, a 50% subsidiary of Continental.

SCR development progress. Reducing the NO_x emission levels of commercial vehicles even further is a core challenge to the industry. There is a practical limit to reducing engine-out NO_x emissions; therefore, many OEMs are likely to opt for SCR as this technology can achieve up to 97 % of NO_x reduction depending on the application.

In a SCR system an aqueous urea solution (AdBlue) is injected into the exhaust flow to facilitate the conversion of nitrogen oxides in a catalytic converter. The AdBlue liquid dosage has to be controlled with precision; it needs to be aligned with the amount that is required instantaneously; and all this has to happen within a quick reaction time in order to limit the AdBlue consumption.

Continental supplies core components for this task: As of 2013 newly developed air-cooled AdBlue injectors for light-duty applications will be manufactured. In parallel Continental is developing a liquid-cooled version for heavy truck applications.

AdBlue injectors are located ever closer to the engine in commercial vehicles and are thus exposed to more heat. This makes liquid-cooling a precondition for future close-coupled solutions.

—Dr. Detlev Schöppe, Head of the Engine Systems Business Unit´s R&D within the Powertrain Division

Another innovation currently under development is a urea sensor based on ultrasonic measurement. This sensor measures the urea concentration and the filling level of the AdBlue tank. The Continental NO_x sensor, on the other hand, which measures the amount of nitrogen oxides in the exhaust gas to verify the NO_x abatement efficiency and serves to adjust the AdBlue injection, is already available to the market. Heatable hose modules, manufactured by ContiTech, are also part of the SCR system competence.

A further element of the Continental system competence is the actual AdBlue dosage strategy. Continental’s generic exhaust gas control unit for commercial vehicles is an established solution. This ECU is now available in its second generation and offers hardware and software for DPF control, for instance.

SCR as an efficient way of NO_x abatement brings about yet another economic advantage: As a rule the most fuel efficient engine management strategy results in the highest NO_x emissions.

SCR opens up greater levels of freedom to run an engine in a NO_x-rich part of the map without impacting vehicle emissions, which are measured downstream of the aftertreatment system.

—Dr. Detlev Schöppe

Managing the diesel particulate filter. Many future commercial vehicles are likely to use a combination of SCR and diesel particulate filter to clean the exhaust gas. As the hot gas passes through both units, it is important to protect them against overheating. In order to avoid a DPF from being damaged during the regeneration phase by overly high temperatures, Continental has developed an active high temperature sensor, which reacts particularly quickly and exactly to changes in temperature. The dosage unit that is needed to inject the diesel is also included in the Continental portfolio.

The new Continental soot sensor will serve to monitor the exhaust gas flow downstream of the catalytic converter, in order to confirm the correct operation of the exhaust gas aftertreatment and to provide this information to the on-board diagnosis.