Man L23/30DF, Project Manual

Page: 235 / 392

Introduction
SCR technology
MAN Diesel & Turbo decided to develop it's own
SCR technology to be able to optimise the emis-
sions technology and the engine performance in
addition with the MAN Diesel & Turbo own SCR
control programme to the utmost customer benefit.
Common SCR systems require constantly high
exhaust gas temperatures. The MAN Diesel & Turbo
SCR system however is an integrated system
(engine + SCR) that is automatically adjusting the
exhaust gas temperature in an optimal way to
ensure ideal operation of both engine and SCR. For
example, the engine is operating at optimum condi-
tion, however the system is registering an increas-
ing backpressure over the SCR reactor. To resolve
this, the regeneration feature of the integrated SCR
system is activated and the wastegate engaged to
increase exhaust gas temperature. After a short
time, the SCR system is regenerated and the
engine can continue operation in the design point
area. Thus the SCR assures ideal engine operation
by regenerating the SCR system whenever neces-
sary to achieve minimum fuel oil consumption. Nev-
ertheless, the SCR system complies with the IMO
Tier III regulations on NO
X
emissions at any time.
Fuels for operation with SCR catalyst
The SCR components were special designed for
operation with heavy fuel oil (HFO) in accordance
with specification DIN ISO 8217 up to sulphur con-
tent of 3.5 %.
See description 010.000.023-05,
"Specification of Heavy Fuel Oil (HFO)".
Engine overview and SCR system
components
Figure 1: SCR system components overview
Engine and operation
Certification IMO Tier III
The engine's certification for compliance with NO
x
limits according to NO
x
technical code will be done
according scheme B, meaning SCR will be
handled as separate parts. Certification has to be in
line with IMO Resolution MEPC 198(62), adopted
15 July 2011.
Emission level engine: IMO Tier II
Emission level SCR catalyst: IMO Tier III
Certification of engine
Engine will be tested as specified in section Pro-
gramme for Factory Acceptance Test (FAT) accord-
ing to relevant classification rules. It will also certified
as member or parent engine according NO
x
techni-
cal code for emission category IMO Tier II.
See
description B 21 01 1, 1356501-5, "Shop test pro-
gramme for marine GenSet".
MAN Diesel & Turbo
3700467-8.1
Page 1 (17)
SCR (Selective Catalytic Reduction)
B1600 0
V28/32S, L28/32S, L28/32H, L27/38S, L27/38, L23/30S, L23/30H, L21/31S,
L21/31, L16/24S, L16/24