WinGD X92DF User Manual

4.15.2.2 HP SCR system - bypass
In this operation mode, the HP SCR system is bypassed. The engine operates in Tier II mode.
Urea solution is not injected.
If you change from Tier III mode to bypass mode, the HP SCR control system changes the
valve conditions and starts the preservation sequence. If a condition for correct operation for
Tier III mode is not given, the HP SCR control system automatically changes to bypass mode.
•
First the valves have the conditions that follow (refer to Figure 4-28):
○
V1 - Slowly changes from open to closed
○
V2 - Slowly changes from open to closed
○
V3 - Open
○
V4 - Controlled by the ECS, can be more opened to decrease the scavenge air
flow and thus to increase the exhaust gas temperature
○
V7 - Closed, can be opened to decrease the pressure in the reactor
•
Then the preservation sequence starts as follows to prevent corrosion of the reactor and
of the pipes (refer to Figure 4-29):
○
The purging sequence uses compressed air to remove the remaining urea solution
from the injection equipment, from the pipes and from the reactor.
○
The venting/sealing unit starts and the valve V7 opens for some minutes. Thus the
compressed air removes the exhaust gas to the exhaust gas system of the plant.
•
If the venting/sealing unit is unserviceable, decrease the pressure in the reactor and drain
the condensation.
Fig 4-28 HP SCR system - change from Tier III to bypass
V1 V2
V3
V7
V4
003
001
007
006
005
004
002
00525
X92DF
AA00-9270-00AAA-043A-A
Operation Manual HP Selective catalytic reduction system
Winterthur Gas & Diesel Ltd.
- 124 - Issue 002 2020-08

WinGD X92DF Specifications

General

Brand	WinGD
Model	X92DF
Category	Engine
Language	English