Development of an Active Regeneration System

Based OnCatalytic Combustion

Active regeneration Based on secondary fuel injection and catalytic combustion

0

10

20

30

40

50

60

150 200 250 300 350 400 450

Inlet Temperature (°C)

Soot

Oxi

datio

n R

ate

(g/h

r)

4.8 g/L

2.4 g/L

0.6 g/L

Soot oxidation rate

0

50

100

150

200

250

300

350

400

600 620 640 660 680

DPF Inlet Temperature (°C)

So

ot

Ox

ida

tio

n R

ate

(g

/h

r)

NO2 Regeneration

2NO2+C => 2NO +CO2

O2 Regeneration

O2+C => CO2

Active regeneration Based on secondary fuel injection and catalytic combustion

Fuel consumption

0

100

200

300

400

500

0 25 50 75 100 125

Power output (kW)

Expe

cted

Tem

p In

crea

se

(°C)

150 kg/hr

700 kg/hr

1200 kg/hr

0

30

60

90

120

150

0 50 100 150 200 250

Fuel Injection Rate (cm3/min)Po

wer

out

put (

kW)

Active regeneration systemSystem description

- Based on secondary fuel injection

- Catalytic combustion

- Controlled Regeneration

- Ensures required Soot oxidation Rates.

Active regeneration systemMain components

- Fuel supply

- Injection manifold

- Electronic control unit

Control Algorithm

Regeneration start parameters

• Max soot loading is reached.

• And/or min. regeneration time interval reached.

• Acceptable exhaust temperature

Control Algorithm

Regeneration stop parameters

• Injection time has elapsed.

• Engine switched off.

• Temperature after catalyst under low limit over time.

• Temperature after catalyst over high limit.

• System error.

Active regeneration system Field trial

System descriptionInjection manifold / Dosing unit

Combustion catalyst

Fuel delivery system

DPF

Field trial resultsExample of regeneration event

Engine speed

Engine load

Fuel pressure

Air pressure

After catalyst

Before DPF

Exhaust pipe

Before catalyst

After DPF

Field trial resultsExample with regeneration triggered by exhaust back pressure

Exhaust back pressure

Temperatures

After catalystBefore catalyst

140 mbar

Field trial resultsDPF performance

• Low temperature application

• High PM application

• Controlled regeneration

• Succesful regeneration

• Clean tailpipe

Safety features

Control system safety functions• Injection, air pressure and fuel pressure stop at system error.

• System error at high catalyst outlet temp

• System error at hi/lo Fuel and air pressure.

• System error at Injection (PWM) feed back error.

• System error at EGR error (if used)

• Fuel pressure only in injection mode