The conventional aftertreatment systems to meet the stringent ULEV-II emission regulation are usually composed of warm-up catalytic converter (WCC) and underfloor catalytic converter (UCC). However, those systems bring high cost, high back pressure, the limit of engine room for package design, and other side effects.[4] The new optimized system needs to solve these problems and to meet ULEV-II emission regulation efficiently.
There are many technologies and design parameters in exhaust catalytic converter systems; exhaust manifold structure[9], exhaust gas flow distribution, location of catalytic converter, PM coating technologies[1], substrate characteristics, and volume of catalysts. It is a key factor to make a optimized robust system with those parameters and technologies described.
The new optimized exhaust and Integrated Close-coupled Catalytic Converter (ICCC) system can meet ULEV-II regulation and can solve those problems of conventional system by a robust design. This study was focused on the optimization process of exhaust and ICCC system to determine robust design control factors, which are durability of catalyst - aged and/or fresh -, by vehicle evaluation, FTP-75.