Cost-Effective D-DPF Design of Aftertreatment System for Non-Road Mobile Machinery China Stage IV

<div class="section abstract"><div class="htmlview paragraph">Since Non-Road Mobile Machinery (NRMM) China stage IV legislation has been implemented from 2022, some engines within maximum rated power between 37 to 560 kW are required for gaseous emissions, particulate matter (PM) and particulate number (PN) control, evaluated over testing cycle of Non-Road Transient Cycle (NRTC) and Non-Road Steady Cycle (NRSC). The pollutants from diesel engines, widely used in NRMM applications, can be controlled using aftertreatment systems which are comprised of a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF), or optionally a selective catalytic reduction (SCR). In this paper, a compact D-DPF design is introduced and discussed on application in harvesters, tractors, and forklifts. Because harvesters have higher exhaust gas temperature than other applications, more passive regeneration behaviors were observed. Subsequently, a compact design of DOC catalyst on DPF (D-DPF) was studied, in other words is to coat DOC catalyst on DPF. For a diesel engine with 3.6 litter(L) displacement application, the total length of D-DPF was shortened around 15% compared to the conventional design of a DOC and a downstream DPF. Meantime, D-DPF design also has higher gaseous emission conversion rate for CO and hydrocarbons (HCs) at high temperature range. The soot loadings can be balanced in the D-DPF system for long time during real operating condition for harvesters’ machinery. By fuel injection upstream of D-DPF, the temperature in the middle of D-DPF can reach 600 °C to actively regenerate the DPF. This type of design of D-DPF is proved to be a very cost-effective solution for NRMM China stage IV application with real operation condition and relevant testing data.</div></div>