Air quality in the urban regions is already a topic for decades. Although we see a shift of propulsion systems towards electric vehicles, the combustion engine will accompany us for further decades along with air pollution issues. The team for advanced measurement solutions at Virtual Vehicle identified and picked up the emission topic already long before the “VW Dieselgate” became public. Measurement technology has always been the enabler for innovation and technology optimization.
The biggest issue around Diesel engines are the NOX emissions. The most promising technology for exhaust aftertreatment is the selective catalytic reduction (SCR). SCR uses a urea-water solution (AdBlue®) being injected into the exhaust gas. The AdBlue® is converted to ammonia which acts as reduction agent for NOX within the SCR reaction. This process is well known for stationary power plant processes but for the application in vehicles and their dynamic behaviour the process turns out to be very complex to parametrize. Depending on the operating conditions several problems like underdosing, overdosing or solid depositions can lead to a complete system malfunction.