The regeneration of a loaded particulate filter is one of the biggest challenges in the development of filter systems. The reason is under certain conditions the exhaust gas temperature does not reach the required minimum regeneration temperature for a longer period of time.
This paper describes results achieved with a catalytically coated filter alone and in combination with engine parameters, which are used to increase the exhaust gas temperature.
The activity of the catalytically coated filter was evaluated by using the well-known balance temperature test. The soot-burning rate was determined at different exhaust gas temperatures.
The investigated engine control parameters included intake air throttling and a control of lambda.
A special low-temperature transient test was designed to evaluate the regeneration efficiency of the catalytically coated filter and the described engine control parameters under more realistic conditions.
The results achieved in this examination show that the optimized catalytically coated filter in combination with engine control parameters can extend the operating range of a filter system. The combination enables the system to regenerate the loaded filter even at low temperature operation.