The HP SCR system can be operated, if the exhaust gas temperature after the exhaust gas
manifold is in the permitted limits shown in
Table 4-1 - Operation limits of exhaust gas temperature
. A temperature that is less than the given limit can cause the catalyst
elements to clog. A temperature that is more than the given limit can cause the catalyst elements
to age faster.
Tab 4-1
Operation limits of exhaust gas temperature after exhaust gas manifold
Operation mode
T
min
T
max
Preparation (urea injection OFF)
200°C
470°C
Use of low sulphur fuel (
≤
0.5% S) (urea injection ON)
310°C
470°C
Use of high sulphur fuel (> 0.5% S) (urea injection ON)
325 to 340°C
470°C
1
Refer to the HP SCR system documentation if the operation of the HP SCR system with
high sulphur fuel is permitted.
2
The engine control system (ECS) calculates this value related to the engine load and to
the exhaust gas pressure.
4.12.2
Operation modes
The HP SCR system has the operation modes that follow.
NOTE:
The text and the figures that follow are related to an engine with one turbocharger. The
text and the figures are also applicable for an engine with two turbochargers.
X52
AA00-9270-00AAA-043A-A
Operation Manual
HP Selective catalytic reduction system
Winterthur Gas & Diesel Ltd.
- 94 -
Issue 002 2018-11
