Marine Installation Manual
2022-03
7-2
7 Engine Emissions
7.1 Exhaust gas emissions
X62DF-S2.0
7.1.1
Regulation and calculation criteria for NO
x
emissions
Regulation 13 of MARPOL Annex VI specifies a limit for the nitrogen oxides
(NO
x
) emissions for engines installed on ships. This has a direct implication on
the design of propulsion engines.
NO
x
Technical Code
The rules and procedures for demonstrating and verifying compliance with Reg
-
ulation 13 of MARPOL Annex VI are provided in the NO
x
Technical Code,
which is part of Annex VI and is largely based on the latest revision of ISO 8178.
NO
x
Calculation criteria
Depending on the rated speed of the engine and the date of vessel keel-laying, the
weighted average NO
x
emission of the engine must not exceed the maximum al
-
lowable value as indicated by the respective curves in
Figure 7
-
2 Speed dependent maximum allowable average of NO
x
emissions
NO
x
emissions can be calculated with the following conversion formula:
Formula 7
-
1
where:
m
NOx
.......... = Nitrogen oxides emissions [kg/h]
NO
x
............= Nitrogen oxides emissions [g/kWh]
P
ME
........... = Engine power [kW]
The NO
x
in
is a project-specific value and it is a function of the en
-
gine type and power. WinGD can provide guidance values for NO
x
emissions
upon request.
SM-0084
0
0
2
4
6
8
10
12
14
16
18
20
200
A
B
C
400
600
800
1000
1200
1400
1600
1800
2000
Engine speed [rpm]
NO
X
emission [g/kWh]
A
B
C
Tier I: 1
st
January 2000 global
Tier II: 1
st
January 2011 global. After 2016 outside emission control areas
Tier III: 2016 in emission control areas
1000
x
ME
NO
x
P
m
NO
