active regeneration 600˚C(fast) :C+O2->CO2/CO (with fuel add Ce, Fe can be 380~450˚C)
*J.M.CRT:C+NO2->NO+CO/CO2, but not good for PV, regen time=30min, need sulfur deactive catalyst
What is the effect of fuel additive
without fuel add is for-life solution (>20000km)
with fuel add is maintenance required.
what control the activation of regeneration?
what is the objective of strategy of O2based?
what strategy can use?
air flow meter sensor, inlet DPF temp sensor, DPF press drop sensor
monitoring PM loading, inlet T>600, O2>5%
pilot & main inj. timing retarded, after & post injection activation(IDLE:also multiple inj), inj P variation,
EGR reduction or deactivation
inlet fresh air reduction(?)
what assessment used for catalyzed DPF critical regeneration events?
thermal shock test (activation of RGN at 1750rpm 1,5bar for 2 min, until the combustion start--P drop peak)
measurement of DPF T evolution
why DPF regeneration management is more critical if use BIODIESEL on standard diesel engines without modification?
regeneration rate of BDF is twice as fast as that of Diesel. (higher regeneration efficiency)
Biofuel has lower soot mass limit than conventional diesel.
higher max T and T gradient
high filtration efficiency (>90%)
high thermal resistance (no damage up to 1200˚C)
high mechanical resistance (isostatic strength>4 Mpa)
high chemical inertia
high porosity (>42%)
low pressure drop (<7kPa @ 600 m3/h)
the function of filter wall active "layer"
catalyze soot combustion during RGN, minimize residual soot
reduce CO&HC emission during regeneration
DPF design preferance
volume: ↑better for technical function (↓RGN frequency & ∆P, ↑ oil change interval & ash tolerance), worse for cost ,wight, vehicle intergration
Length/diameter:↓better for reliability, RGN frequency, ∆P 宁胖不瘦
the material used for DPF
outside can: metallic
monolith: cement(flexible enough when temperature change, componsate the stress)
why use Close Coupled PDF from E4 to Euro 5?
1) 50˚C increase of exhaust T <- exhaust T is a function of distance from outlet turbine
2) -35% time to reach the same reg T3) ↑ viscosity, ↓ oil dilution
1)ECU sensors for DPF? 2)Vehicle mission profile will have impact on? 3)What is Soot Loading Driving Parameters? 4)What is regeneration activation driving Parameters? 5)When will RGN activated? 6)What parameters have impact on RGN duration?
1) 2 ex gas T: outlet pre cat, inlet DPF Pressure: DPF P drop