Wartsila 31, Руководство по эксплуатации продукта

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Fig 12-1 IMO NO
x
emission limits
IMO Tier 2 NO
x
emission standard (new ships 2011)
The IMO Tier 2 NO
x
emission standard entered into force in 1.1.2011 and applies globally for
new marine diesel engines > 130 kW installed in ships which keel laying date is 1.1.2011 or
later.
The IMO Tier 2 NO
x
limit is defined as follows:
= 44 x rpm -0.23 when 130 < rpm < 2000 NO
x
[g/kWh]
The NO
x
level is a weighted average of NO
x
emissions at different loads, and the test cycle is
based on the engine operating profile according to ISO 8178 test cycles. The IMO Tier 2 NOx
level is met by engine internal methods.
IMO Tier 3 NO
x
emission standard (new ships from 2016 in ECAs)
The IMO Tier 3 NO
x
emission standard will enter into force from year 2016. It will by then apply
for new marine diesel engines > 130 kW installed in ships which keel laying date is 1.1.2016
or later when operating inside the North American ECA and the US Caribbean Sea ECA.
The IMO Tier 3 NO
x
limit is defined as follows:
= 9 x rpm
-0.2
when 130 < rpm < 2000 NO
x
[g/kWh]
The IMO Tier 3 NO
x
emission level corresponds to an 80% reduction from the IMO Tier 2 NOx
emission standard. The reduction can be reached by applying a secondary exhaust gas
emission control system. A Selective Catalytic Reduction (SCR) system is an efficient way for
diesel engines to reach the NOx reduction needed for the IMO Tier 3 standard.
If the Wärtsilä NOx Reducer SCR system is installed together with the engine, the
SCR installation complies with the maximum permissible NOx emission according to the IMO
Tier 3 NOx emission standard and the Tier 3 EIAPP certificate will be delivered for the complete
installation.
12-4 Wärtsilä 31 Product Guide - a1 - 18 October 2016
Wärtsilä 31 Product Guide 12. Exhaust Emissions