Patent ID: 7426825
Filing Date: 2008-09-23
Classification: F01N,Y02T

Abstract:
1. An exhaust gas aftertreatment control system for an internal combustion engine operable lean of stoichiometry, comprising: an exhaust aftertreatment system including a sensing device operative to monitor temperature and concentration of NOx gases in an exhaust gas feedstream upstream of a the selective catalyst reduction device, a urea injecting device, a selective catalyst reduction device located downstream of the urea injecting device, the selective catalyst reduction device including upstream and downstream portions relative to exhaust gas flow; and a sensing device operative to monitor only the upstream portion of the selective catalyst reduction device; and, a control module adapted to monitor signal inputs from the engine, the sensing device operative to monitor temperature and concentration of NOx gases in the exhaust gas feedstream upstream of the selective catalyst reduction device, and the sensing device operative to monitor only the upstream portion of the selective catalyst reduction device, said control module controlling operation of the urea injecting device based on selected ones of the monitored signal inputs and including: