Skip to main content

NOx Technical Code

MARPOL Annex VI requires all diesel engines installed after 1st January 2000, with a power output of more than 130 kw to be tested and issued with an Engine International Air Pollution Prevention (EIAPP) certificate and an approved NOx Technical File. 

The approved Technical File provides details of the allowable engine components settings, operating values and allowable adjustments which ensure the engine will continue to operate within the acceptable NOx emission limits. 

This EIAPP certificate and approved Technical File stays with the engine and remains valid for its marine life. 

Periodic verification surveys are carried out by the classification to confirm the engine continues to operate within the on-board NOx emission limits.

If any adjustment, part replacement and modifications are carried out, which influences NOx emission characteristics should be recorded chronologically in an engine’s record book of engine parameters. ID numbers of all such components used are to be recorded.

The ID numbers are stamped on these parts and record them before fitting them to the engine

For Eg: the ID number of a cylinder liner usually stamped just above the scavenge ports, on the injection nozzle of a fuel injector valve. The location of ID numbers of these components will be mentioned in the NOx technical code.

When adjusts are made on FQS(Fuel Quality Setting)/ VIT (variable Injection timing) and for operational reasons, the limits mentioned in the Nox Technical file should not be exceeded.

The following are the list of components and settings that influence the NOx Emission:
a) Fuel injection timing
b) Fuel injector nozzle
c) Fuel pump plunger & barrel
d) Fuel cam
e) Exhaust cam
f) Cylinder cover
g) Piston crown
h) Cylinder liner
i) Turbocharger
j) Compressor wheel / turbine rotor
k) Diffuser / nozzle ring
l) Aux blower
m) Scavenge air cooler
n ) Governor
o) Shim thickness to change the compression ratio and if shims used on the fuel pump

The above guide lines are applicable for the auxiliary engines also.

The Code will apply to any diesel engine with a power output of 130 kW and above installed on a ship whose keel was laid on or after 1 January 2000, or any diesel engine with a power output of 130 kW and above which has undergone a major conversion on or after 1 January 2000, except those intended solely for emergency use. Major modification means the maximum continuous rating of the engine is increased by more than 10% or the engine is replaced by a new engine built on or after 1 Jan 2000.


According to MARPOL Annex VI
This regulation shall apply to:
(i) each diesel engine with a power output of more than 130 kW which is installed on a ship constructed on or after 1 January 2000
(ii) each diesel engine with a power output of more than 130 kW which undergoes a major conversion on or after 1 January 2000.

This regulation does not apply to:
(i) emergency diesel engines, engines installed in lifeboats and
any device or equipment intended to be used solely in case
of emergency
(ii) engines installed on ships solely engaged in voyages within
waters subject to the sovereignty or jurisdiction of the
State the flag of which the ship is entitled to fly, provided
that such engines are subject to an alternative NOx control
measure established by the Administration.


What is major conversion ?

(i) the engine is replaced by a new engine built on or after 1 January 2000
(ii) any substantial modification made to the engine
(iii) the maximum continuous rating of the engine is increased by more than 10%.



The maximum NOx allowed on engines are as follows:

From 1st January 2000 to 31st December 2010 (Outdated):

For engines less than 130RPM : 17g/kWh
For Engines between 130 and 2000 rpm, a formula is used:45 × n-0.2 g/kWh
For engines above 2000 rpm: 9.8g/kWh

From 1st January 2011 to 31st December 2015 the limits change (Outdated):
For engines less than 130RPM: 14.4g/kWh
For Engines between 130 and 2000 rpm: 44 × n-0.23 g/kWh
For engines above 2000 rpm: 7.7g/kWh

After 2016 ......Currently this is followed:
For engines less than 130RPM: 3.4g/kWh
For Engines between 130 and 2000 rpm: 9 × n-0.2 g/kWh
For engines above 2000 rpm: 2.0g/kWh

where n = rated engine speed (crankshaft revolutions per minute).


Labels:

Comments

Post a Comment

Popular posts from this blog

Difference Between A, B & C-Class Divisions?

IMO Symbol A Class Division  IMO Symbol B Class Division  SOLAS has tables for structural fire protection requirement of bulkheads and decks. The requirements depend on the spaces in question and are different for passenger ships and cargo ships. The Administration has required a test of a prototype bulkhead or deck in accordance with the Fire Test Procedures Code to ensure that it meets the above requirements for integrity and temperature rise. Types of Divisions: "A" Class "B" Class "C" Class "A" Class: "A" class divisions are those divisions formed by bulkheads and decks which comply with the following criteria: They are constructed of steel or equivalent material They are suitably stiffened They are constructed as to be capable of preventing the passage of smoke and flame to the end of the one-hour standard fire test. they are insulated with approved non-combustible materials such that the average tempera...
14 comments
Read more

Bilge Injection Valve

Bilge Injection is a valve that enables the engine room bilges to be pumped out directly overboard in the event of an emergency such as flooding. The valve is normally fitted to the end of a branch connection with the main sea water suction line. This enables large main seawater cooling pumps to be used as a bilge pump in an emergency. Emergencies like fire and flooding involve the use of seawater. If there is a fire, seawater is the biggest resource of water available in the sea. Similarly, if it involves flooding of the engine room, cargo spaces or any other place on the ship for that matter; you would again require pumping the sea water out of the ship. In both these cases, you require pumps.  There are two valves in close proximity namely main injection valve and bilge injection valve. Both of them have their own independent controls. The diameter of the bilge injection valve is kept nearly 66% of the main valve diameter which draws water directly from the sea th...
Post a Comment
Read more

Load Line & Why it is Important

Merchant ships have a marking on their hull know as the Plimsoll line or the Plimsoll mark, which indicates the limit until which ships can be loaded with enough cargo, internationally, the Plimsoll line on a ship is officially referred to as the international load line. Every type of ship has a different level of floating and the Plimsoll line on a ship generally varies from one vessel to another.  All vessels of 24 meters and more are required to have this Load line marking at the centre position of the length of summer load water line. There are two types of Load line markings:- Standard Load Line marking – This is applicable to all types of vessels. Timber Load Line Markings – This is applicable to vessels carrying timber cargo. These marks shall be punched on the surface of the hull making it visible even if the ship side paint fades out. The marks shall again be painted with white or yellow colour on a dark background/black on a light background.  ...
15 comments
Read more