Search Results

With the push towards more stringent on-road US heavy duty diesel regulations (i.e. HD GHG Phase 2 and the proposed ARB 20 mg/bhp-hr NOx), emission system packaging has grown critical while improving fuel economy and NOx emissions. The ARB regulations are expected to be implemented post 2023 while regulation for EU off-road segment will begin from 2019. The regulation, called Stage V, will introduce particle number (PN) regulation requiring EU OEMs to introduce a diesel particulate filter (DPF) while customer demands will require the OEMs to maintain current emission system packaging. A viable market solution to meet these requirements, especially for EU Stage V being implemented first, is a DPF coated with a selective catalyst reduction (SCR) washcoat (i.e. SCRonDPF).

Honeycomb substrates are widely used to reduce harmful emissions from gasoline engines and are exposed to numerous thermal shocks during their lifetime making thermal shock resistance one of the key factors in designing honeycomb substrates. More stringent emission regulations will require the honeycomb substrates to be lighter in weight to improve light-off performance and to have better thermal shock resistance than conventional honeycomb substrates to handle higher expected temperature gradients. Thermal shock resistance is generally evaluated on a substrate by evaluating the thermal strain caused by temperature gradients inside the substrate during durability testing [1,2]. During the test, a heated substrate is cooled at a surface face to generate temperature gradients while the temperature inside the honeycomb substrate is monitored by multiple thermocouples.