Diesel Engine Cold Starting with Catalytically Ignited Recirculated Exhaust Gas 940086
A system using catalytically ignited recirculated exhaust gas (EGR) has been shown to be capable of starting a heavy-duty diesel engine at temperatures as low as 31.6°C (-25°F) within one minute cranking following US Army Cold Start procedure 2-2-650. A Cummins 6-cylinder C8.3 automotive diesel engine was provided with an EGR pipe fitted with a catalytic ignitor/burner. During starting, the catalyst was kept above the activation temperature by a low power electric power supply. With this system, the unburned fuel in the EGR gas was rapidly ignited by and partially oxidized within the catalytic ignitor/burner, and then mixed with the fresh air before being inducted into the cylinders. The elevated inlet charge temperatures increased the compression temperature, thus promoting autoignition and therefore engine starting. Comparisons were made between starting attempts with and without using catalytically ignited EGR. Pilot fuel additions to the catalytic ignitor/burner on starting were also investigated and found to allow starting well below -31.6°C (-25°F).