· Insulated tube turbulence mixer technology to allow a homogeneous urea hydrolysis and distribution in the exhaust gas stream by introducing a swirling motion.
This combination of the above patents allows NOx reduction efficiencies in excess of 95%, reaching levels very close to 100% under specific circumstances.
New Euro VI Tector and Cursor Engines
By way of continuous technical advances to an already state of the art engine range, Euro VI sees the introduction of new Tector and Cursor engines, allowing Iveco vehicles to retain their class leading fuel economy.
Key to the optimisation of combustion efficiency is high mean effective cylinder pressure and high injector nozzle pressures. To achieve these aims, important changes to the crankcase and cylinder head designs incorporate increased structural rigidity, higher coolant flow capacity and increased swept volume.
The Tector and Cursor engines both received the latest generation of multiple event common rail fuel injection equipment with peak nozzle pressures of up to 2200 bar.
A new electronic control unit has been introduced to manage both engine parameters and accurate control of the after-treatment system. The new control unit has been designed to optimise packaging and to fully integrate all engine, SCR and DPF functions. For Cursor engine versions using the variable geometry turbocharger, electronic control has been introduced to optimise load response at low engine speeds and to increase the effectiveness of the engine brake. In addition, all engines will now make use of the flap type engine brake valve in order to support passive DPF regeneration and to improve engine brake performance by up to 30% compared to current Euro V engines.
For the very best in environmental performance, Tector and Cursor engines were equipped with closed circuit engine breathing systems even at Euro IV/V level and this feature is retained for Euro VI. In order to prevent any oil mist carried in engine blow-by gases, very high performance oil separation systems have been introduced serving to reduce to the absolute minimum any oil burning with consequent DPF contamination. For Cursor engines, an oleophobic centrifugal oil separation is used while for the Tector engine, a high efficiency valve cover integrated coalescent type blow-by filter is used.
The introduction of the new Euro VI compliant engines emphasises Iveco’s and FPT Industrial’s continuous push towards sustainable mobility. In terms of fuel consumption, serviceability, carbon footprint and corporate image, Iveco has put its customers in the front row, achieving vehicles meeting the full requirements of this important new environmental standard and retaining the lowest possible cost of ownership.
By means of the optimised combustion regime, engine-out particulate emissions are already low, meaning that forced regeneration of the DPF is not required, an important aspect in terms of fuel use and periodic servicing. In addition, since the engine only breathes clean filtered air, rather than recirculated exhaust gases, engine wear is maintained very low and oil change intervals are maintained high, with service intervals of up to 150,000 km. This too brings advantages in terms of operating costs and reduced down time for scheduled maintenance.
A fundamental aspect of diesel combustion is the emission from the engine of oxides of nitrogen and particulate matter, both very difficult to eliminate together in the combustion chamber. Diesel fuel contains neither nitrogen nor oxygen and so NOx creation results from chemical changes to combustion air due to the high cylinder pressures and temperatures experienced during the combustion process. In cylinder NOx reduction techniques involve measures to reduce maximum cylinder temperatures and pressures that, paradoxically, increase the creation of particulate matter and reduce combustion efficiency resulting in increased fuel consumption. Once the need for exhaust after-treatment is accepted, it is clearly necessary to make the system work as hard as possible in order to not compromise the engine combustion process. The choice made by Iveco and FPT Industrial is to reduce particulate matter to the absolute minimum, allowing engine-out NOx emissions to increase due to the improved combustion efficiency resulting from this measure and the “SCR Only” technology in the exhaust system allows the NOx reduction to be made. The modest engine-out PM emissions are brought to the necessary levels using a full-flow Diesel Particulate filter that will achieve continuous regeneration due to the high exhaust NOx levels and the high gas temperature. Forced filter regeneration will not be necessary under normal circumstances.
A new generation Zeolite based compact SCR after-treatment system with all integrated components has been designed to optimise layout and minimise weight impact, resulting in a single, simple box shaped including DOC (Diesel Oxidant Catalyst), DPF (Diesel Particulate Filter), SCR (Selective CatalyticReduction) and CUC (Clean-Up Catalyst). All these components have been installed with extreme compactness, achieving superior conversion efficiencies for all pollutants. In the very same box the AdBlue injection/mixing devices, as well as all exhaust gas sensors needed for the after-treatment management, are carefully integrated.
This allows the entire exhaust after-treatment to be contained in a compact, fully enclosed structure thereby not impeding body building or chassis equipment mounting activities.
In more detail, Euro VI tailpipe emission levels have been achieved with a robust engineering margin by means of innovative design and accurate testing and modelling activities. The result is perfect tuning of DOC, DPF, SCR and CUC coatings to grant maximum conversion efficiency without significant ageing for the full vehicle life. A clear-cut design of inlet and outlet substrate areas allows for the complete exploitation of the catalyst installation in its confined volume, including the AdBlue injection area with controlled turbulence and optimised thermal insulation. This guarantees perfect AdBlue aerosol mixing and urea hydrolysis prior to reaching the SCR. With precise positioning of exhaust gas sensors, a rapid and precise monitoring of all catalytic substrates and on-going chemical reactions is achieved.