Critical Performance and Durability Parameters of an Integrated Aftertreatment System used to Meet 2007 Tier II Emission Standards

Durability and reliability in diesel engine system design

“…They introduced various durability test procedures for DPF substrate and the entire DPF assembly, including on-engine accelerated DPF thermal aging test cycle, accelerated ash accumulation test, hot and cold vibration tests, stepped vibration test, water quench test, thermal profile test, and on-vehicle DPF durability test. Stroia et al (2008) discussed durability test procedures for a diesel aftertreatment system consisting of DOC, LNT, and CDPF. DPF durability analysis on stress and fatigue life was conducted by Gulati et al (1992), Umehara and Nakasuji (1993) and Kuki et al (2004).…”

Diesel aerosols and gases in underground mines: guide to exposure assessment and control.

“…It has been demonstrated that DPF systems have a useful life of several thousand hours WRAP 2005;D'Urbano and Mayer 2007;Mayer et al 2008]. Typical causes of useful-life failures of DPF elements include stresses induced by mechanical vibrations, stresses from high exhaust temperatures generated during normal operation as well as uncontrolled regenerations, and catalyst degradation from thermal stress or chemical poisoning [Stroia et al 2008;Kim et al 2008;Dabhoiwala et al 2009]. In the case of uncontrolled regeneration, the exhaust temperatures can reach in excess of 925°C (1,697°F) [Watts et al 1995;DieselNet 2005b].…”

“…Switching from LSD to ULSD has a minor potential for reducing exposures of underground miners to elemental and total carbon [NIOSH 2006b]. However, reducing the amount of sulfur and sulfuric compounds in the vehicle exhaust will help prevent irreversible degradation of aftertreatment catalysts [Stroia et al 2008] . Therefore, the introduction of ULSD is a critical step toward the implementation of catalyzed diesel particulate filters, NO X control technologies, and other catalyzed aftertreatment systems.…”

Lean Gasoline Engine Reductant Chemistry During Lean NOx Trap Regeneration

“…Recently, diesel engine vehicles have been commercialized for the U.S. market that meet NOx emissions regulations by employing catalysts for lean NOx control. [2] Two catalytic approaches have been used: ureabased selective catalytic reduction (urea-SCR) and lean NOx trap (LNT) catalysts. The urea-SCR approach requires the on-board storage of urea which is introduced into the exhaust upstream of the SCR catalyst, converted to NH 3 via hydrolysis reactions, and interacts with NOx on the SCR catalyst.…”