This paper summarizes the investigative work done to evaluate the effects of diesel substrate mounting materials on substrate surface temperatures and external shell surface temperatures. For the work completed, a test set-up and protocol was established, test results were obtained for different materials, a representative thermal model was developed, and the experimental test results were compared to the thermal model results.
A stationary diesel engine incorporating secondary fuel injection for active regeneration was employed. The base test exhaust emission control systems consisted of a DOC + uncatalyzed DPF configuration. An appropriate data acquisition and thermocouple map was developed to monitor the exhaust system temperature conditions. The test cycle employed consisted of a soot loading segment, a standard filter regeneration segment, and a transient regeneration segment. A 3D thermal model was developed to enable more detailed evaluation of heat transfer within the exhaust system.
This work and fundamental understanding is important toward understanding the relationship that the substrate mounting material has internally on the diesel emission control system thermal uniformity and externally on the shell surface temperatures. This relationship may be important to key system performance parameters such as catalyst conversion efficiency, filter regeneration effectiveness, fuel economy, and filter durability. Additionally, the test and modeling capability are important tools toward establishing good thermal management and time efficient design protocols.
The work to-date was successful in developing the appropriate test methodology and capability in a laboratory environment. The test results indicate that differences in mounting material properties have relatively minor in-use effects on substrate surface and external shell surface temperatures. A representative thermal model was developed to understand the experimental test results.