Fig 4-27
LP SCR bypass rate controlled (example)
V3
V1
V4
V2
002 003
005
001
006
004
Legend
001
Engine
004
Burner
002
Urea dosing unit
005
LP SCR reactor
003
Decomposition unit
006
Turbocharger
4.13.2
Operation modes
The LP SCR system can be operated if the exhaust gas temperature is in the permitted limits.
These limits are adjusted during commissioning. A temperature that is less than the permitted limit
can cause the catalyst elements to clog. A temperature that is more than the permitted limit can
cause the catalyst elements to become worn quickly.
4.13.2.1
LP SCR system - (emergency) bypass
In this operation mode, the LP SCR system is bypassed. The engine operates in Tier II mode.
Urea solution is not injected.
The valves have the conditions that follow:
•
V1 - closed
•
V2 - closed
•
V3 - open
•
V4 - the control systems control this valve.
X72-B
AA00-9270-00AAA-043B-A
Operation Manual
LP Selective catalytic reduction system
Winterthur Gas & Diesel Ltd.
- 118 -
Issue 003 2021-12