Diesel Systems Denoxtronic 2.2 – Urea Dosing System for SCR Systems
To meet the world’s strictest limits for nitrogen-oxide
Denoxtronic 2.2 with engine coolant heating EDC control unit
Engine coolant for Dosing Module
Temp. sensor
Temp. Return sensor line
Supply Module
Dosing Control Unit (optional) Actuators
AdBlue/ DEF tank
Inlet line
Engine CAN Diagnosis CAN
Level sensor Engine coolant line
Sensors
Dosing Module
emissions in the future, efficient exhaust-gas treatment
Temp. sensor
NOx sensor
systems are mandatory. With our Denoxtronic for commercial vehicles, we introduced such a system to the market as long ago as 2004. It was a great success and in 2008 won the “Eco Globe” environment prize in the category of “supplier innovation”. Series production of the third generation Denoxtronic 2.2 started in late 2009 for several customers. An integrated pump in the Supply Module of the
SCR catalytic converter
Denoxtronic feeds the reduction agent AdBlue/DEF (a 32.5-percent solution of urea in water) from the tank to the Dosing Module. This injects the AdBlue/
Customer benefits
DEF directly into the flow of exhaust gas upstream
u Reduction of nitrogen-oxide emissions
of the SCR (Selective Catalytic Reduction) catalytic
by up to 95% u Simplification or omission of internal engine
measures for emission reduction u Improved efficiency of the diesel engine
(by around 3%)
converter. The urea is then converted via hydrolysis into ammonia required for the further reaction. In the second step, inside the SCR catalytic converter, the ammonia reduces the exhaust-gas nitrogen oxides into harmless water and nitrogen. The electronic control can be integrated into the engine control unit (ECU)
Advantages by innovation
or, alternatively, into a Dosing Control Unit (DCU).
u Modular design with separate components –
The control unit matches the amount of AdBlue/DEF
Supply Module, Dosing Module and optional
precisely to the relevant engine parameters. In this way
Dosing Control Unit (DCU) – for flexible adap
it is possible to reduce NOx emissions by up to 95%.
tation to various packaging and installation situations u Dosing control by closed circuit based
on evaluation of up to two NOx sensors u Control of two Bosch systems with one DCU:
Denoxtronic 2.2 and Departronic (system for particulate-filter regeneration) u Realization of small dosing quantities
and narrow dosing tolerances u Fine AdBlue/DEF atomization u 12 or 24 V operation u Supply Module heated either electrically
or by engine coolant u Cooling of Dosing Module by engine
coolant instead of AdBlue/DEF
Possible applications The Denoxtronic 2.2 has been designed for use in the heavy- and medium-duty segment. Today, it is also successfully used in off-highway applications.
Diesel Systems | Denoxtronic 2.2 Urea Dosing System for SCR Systems
Functional principle
Technical features Dosing quantity (min./max.)
36/7,200 g/h @ 9 bar
The Supply Module draws the AdBlue/DEF out of the
Droplet size
≤ 75 µm Sauter Mean Diameter
tank with a diaphragm pump and compresses it to
Lifetime Supply Module Dosing Module Dosing Control Unit Start/stop cycles
Equals B10: 30,000 h 24,000 h 30,000 h 100,000
This pressure is precisely maintained via the speed
Heating concept
Electrical or by engine coolant
Control of the dosing and heating strategy, as well as
Operating voltage
12 V/24 V
Interfaces AdBlue/DEF Electrical, Supply Module Electrical, Dosing Module
Plastic SAE J2044 3/8” and 5/16” TYCO 12pin Bosch compact
Dimensions Dosing Module
L x W x H: 100 x 60 x 110 mm approx.
Dimensions Supply Module
L x W x H: 220 x 209 x 134 mm approx.
Injection line between Dosing and Supply Module: Length Inner diameter
≤ 10 m 3...6 mm
Fields of application
MD, HD, OHW
Emission target
Euro V/VI, US10, JPNLT, Tier 4, Stage 4
the system pressure of 9 bar required for atomization. of the electric drive motor. The Dosing Module doses and atomizes the required quantity of AdBlue/DEF.
for on-board diagnosis, is carried out by the Dosing Control Unit (DCU) or alternatively a software module in the Engine Control Unit. Depending on several input signals (e.g. NOx emission, engine load) the dosing strategy calculates the required dosing quantity and converts this into a pulse-width-modulated signal for the Dosing Module. The system has a closed control loop. AdBlue/DEF freezes at -11°C. Therefore the system is emptied at engine switchoff and heated before restart to protect it from frost damages. Dosing is started only when the system is ice-free. Outlook Future Denoxtronic development will have many focuses including optimization of the spray, increased
Denoxtronic 2.2 components 1
robustness when the system freezes and optimization 2
for off-highway-specific applications. Another development target is qualifying the Denoxtronic so it can contribute to fulfilling future emission standards in marine applications.
3
1
Supply Module
2
Dosing Module
3
Dosing Control Unit
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Robert Bosch GmbH Diesel Systems Postfach 30 02 20 70442 Stuttgart Germany Fax: +49 711 811-45090
[email protected] www.bosch-diesel.de Printed in Germany 2 920 00P 0LB-C/CCA-201009-En
