Search Results

In the Selective Catalytic Reduction (SCR) exhaust treatment system, the Diesel Exhaust Fluid (DEF) or urea water solution is injected in the form of spray into exhaust gas for mitigating the NOx emissions. One of the challenges adversely affecting its functionality is incomplete thermolysis of the injected urea upstream of catalyst. This leads to the formation of undesirable deposits, which blocks the exhaust system leading to back pressure rise, loss in NOx reduction efficiency and durability issues. The current study attempts to evaluate the influence of several DEF injection configurations on the deposit formation risk in an airless Urea-SCR exhaust system of Diesel engine used for commercial vehicle applications. Combination of experimental methods involving vehicular trials and detailed CFD simulation for modeling wall film were used. Further, the influence of the urea injection angle, injection cone geometry and mixing length on deposit formation risk was investigated.

BS VI or Euro VI Norms mandates the RDE emission compliance for the diesel commercial vehicles. Development of the engine- after treatment system for meeting these requirements needs a greater insight into the emission behavior of the vehicle under current norms i.e. BS IV and Euro V. In other words, quantifying the on road emission of current vehicle will be helpful in developing engine/vehicle for RDE emission compliance. In the current study, the focus is on the assessment of real road NOx emission of a BS IV and Euro V complaint diesel commercial vehicle. The real road emissions of vehicle have been quantified using the onboard NOx sensor mounted on the after treatment system outlet along with a validated exhaust gas model developed and parameterized in engine control unit. The real road NOx emissions were compared with the test bench emissions for various conditions.