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.
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 Formula 7-1 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.
20
200
A
B
C
400 600 800 1000 1200 1400 1600 1800 2000
Engine speed [rpm]
NO
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
E
P