5 July 2012
Volvo Trucks unveiled the Euro VI version of its D13 diesel engine. The Euro VI standards limit NOx emissions at 0.4 g/kWh and PM at 0.01 g/kWh, 77% and 50% below the respective Euro V limits. The D13 is an in-line, six-cylinder, 13-liter engine producing 460 hp. Today, the D13 powers more than one-third of all Volvo trucks.
First trucks with the Euro VI engine will be delivered in Spring 2013. Customer demand for Euro VI trucks is still at a modest level, said Volvo. Since February 2012, it is possible to certify Euro VI vehicles, but the requirements become mandatory for all new trucks only from 2014. The increased cost of Euro VI engines can be partially offset by various financial inducements and incentive packages in regional traffic and long-haul operations in Europe.
The Volvo D13 for Euro VI is based on Volvo’s Euro V engine. Like its predecessor, the new engine is an in-line six cylinder engine with unit injectors and selective catalytic reduction (SCR) aftertreatment for NOx control. In order to meet the new emission requirements, exhaust gas recirculation (EGR) is also used, as well as a diesel particulate filter (DPF)—systems that Volvo trucks have already been using in the United States and Japan.
The exhaust aftertreatment system is integrated into one compact package that includes an oxidation catalyst and DPF unit, a urea mixing box, two parallel SCR catalysts and an ammonia slip catalyst. The particulate filter is passively regenerated during most of normal and high load operation. At low temperature driving cycles, an active regeneration is conducted, involving exhaust injection of fuel to increase DPF temperature.
For NOx control, the engine relies primarily on the SCR system of high, 95% NOx conversion efficiency (presumably over the test cycle). The EGR, which is apparently uncooled, is used to control NOx at light load conditions and to raise the exhaust gas temperature to above 250°C to enable efficient operation of the SCR system. An exhaust brake is used as another component of the thermal management strategy. The EGR system is “virtually inactive” during highway cruising, so it does not impact fuel consumption during such operations.
Source: Volvo Trucks