SCR技术介绍幻灯片.pptVIP

产品与技术简介 —— 欧四、欧五柴油发动机后处理系统 On-Highway EPA Euro Standards Diesel AT Technology Overview Aftertreatment System Product Platforms – Current and Future Technical Capabilities System Technologies System Analysis Tools Cummins Particulate Filter SCR Technology Offers Fuel economy improvement over Euro III Increased power density and lower heat rejection Fuel Sulphur tolerant Engine simplicity – no tech. change from Euro III Service interval improvement (oil drain - low soot) Lower Maintenance Costs (no PM trap) Future proof: technology path to Euro V Urea SCR Chemical Reactions Urea Decomposition and Hydrolysis in Exhaust: NOx Reduction in SCR Catalyst: NO + NO2 + 2NH3 → 2N2 + 3H2O Fast Reaction 4NO + 4NH3 + O2 → 4N2 + 6H2O Dominant Reaction 2NO2 + 4NH3 + O2 → 3N2 + 6H2O Slow 6NO2 + 8NH3 → 7N2 + 12H2O Slow 6NO + 4NH3 → 5N2 + 6H2O Slow Air-assisted SCR System Air-less SCR system Diesel Oxidation Catalyst – For E4 Engine Base Functions: HC Oxidation functions [Hydrocarbons] + O2 = CO2 + H2O CO + 1/2O2 = CO2 NO + 1/2O2 = NO2 (For DPF regeneration) Undesired Function 2SO2 + O2 = 2SO3 SO3 + H2O = H2SO4 ? Sulphate particulates ISF 2.8L DOC Product Close-coupled design Take full advantage of exhaust gas temperature to light off catalyst, under-body configuration not able to meet performance requirement due to temp loss Dimensions - 118mm x 127mm, ~1.4Liter Maximum volume defined by vehicle space constrain Metallic Substrate Better performance than ceramic substrate based on simulation PGM Loading Optimum trade-off between performance and cost We can Offers Canning Cell Subassembly Cell Final Assembly Line * * PARTICULATE [g/HP-hr] 0.01 0.10 0.2 1.2 2.5 4.0 5.0 EPA 1994 EPA 1998 EPA 2004 NOx [g/HP-hr] [g/Kw-hr] Euro 2 Euro 3 EPA 2010 (Euro 6 ?) EPA 2007 Euro 5 2009 Euro 4 2006 0.02 0.10 0.15 2.0 3.5 5.0 7.0 PARTICULATE [g/Kw-hr] NOx/PM Control NOx PM SCR NOx Adsorber HC Based NH3 Based SOF