A Urea-Dosing Device for Enhancing Low-Temperature Performance by Active-Ammonia Production in an SCR System 2008-01-1026
A new urea-dosing device with an active-ammonia production function was developed. This function is achieved by an electrically heated bypass passage with a hydrolysis catalyst for urea-to-ammonia conversion. The new device also has the function of mixing ammonia and exhaust gas. It is compact and has low-pressure loss by using the vortex occurring at the back of a static vane. We built a trial device for a small diesel engine and obtained steady state and transient data. The heated-bypass concept can be used in the aftertreatment system of passenger cars. Although active-ammonia production consumes electric power, a predictive calculation of power consumption (based on experimental results) shows that the developed bypass heater can suppress the energy consumption enough not to harm the high-energy efficiency of diesel engines.
Citation: Nishioka, A., Amou, K., Yokota, H., and Murakami, T., "A Urea-Dosing Device for Enhancing Low-Temperature Performance by Active-Ammonia Production in an SCR System," SAE Technical Paper 2008-01-1026, 2008, https://doi.org/10.4271/2008-01-1026. Download Citation