Ultra-Low Emissions for Light Commercial Vehicles – The HJS Modular Exhaust System

摘要

HJS has developed a modular SCR system for EU6d and beyond emission requirements.The SCR system has been designed for passenger cars, light commercial vehiclesand non-road applications (NRMM) for engine sizes between ~1.5 l - 5 ldisplacement. Engineering targets have been excellent NH3 uniformity upstream SCR,minimum backpressure and very high NOx conversion efficiencies exceeding 95 %.The system has been designed with an integrated electrical thermal management deviceto enable the operation of the system also as a stand-alone system especially forNRMM or retrofit applications. The general system layout is depicted in Fig. 1.A highly efficient AdBlue® mixing section is combined with a copper zeolite SCR, whichcan be varied in length. A two-stage electrical heater has been integrated to realize aheating power of 1.125 kW.A highly sophisticated control structure for the control and diagnosis of the electricalheater has been created and implemented into the HJS ACU control module. Theadaptive, NH3 storage-based SCR control has been optimized thoroughly to enablevery high conversion efficiencies especially at low temperatures.