Skip to main content

Primary NOx Reducing Measures

These are measures aimed at reducing the amount of NOx formed during combustion by optimizing engine parameters with respect to emission. Some of the methods are listed below –
A. Water addition:-
  1. Direct water injection:- Greater heat capacity is utilized to reduce high peak temperatures as the water evaporates immediately upon injection. Rapid evaporation of injected water also helps to create a homogeneous fuel-air mixture.
  2. Emulsified fuel or fuel-water emulsion:- It is favored by some manufacturer claiming a clear reduction in NOx emission at low cost with no significant design changes.
B. Altered fuel injection:-
  1. Delayed fuel injection:- Retarded fuel injection timing retards the combustion process. Nitrogen oxide formation occurs later and with lower concentration.
  2. Common rail control:- It has proven to be a very effective way in combating NOx reduction techniques.
  3. NOx optimized fuel spray pattern:- Different fuel nozzle types and model injection also has an influence.
C. Combustion air treatment:-
  1. Exhaust gas circulation:- This is one method of adding dilutants to intake air, reducing the burned gas temperature for any given mass of fuel and oxygen. But it is more practical for engines burning cleaner fuel such as low sulphur and low ash fuel.
  2. Humidifying the scavenge air:- Injection of very fine water after the turbocharger using special nozzles. The fine water droplets evaporate fast and further heat is introduced in the air cooler and humidifies the combustion air. The drawback is too much humidity can be harmful to the cylinder condition.
  3. Reducing the amount of scavenge air, and hence reducing the amount of excess oxygen available for conversion to nitrogen oxide.
  4. Water-cooled rest gas:- In an electronically controlled exhaust valve timing, it is quite easy to leave some of the exhaust gas in the cylinder. This obviously has a negative impact on engine performance, however, this can be dramatically reduced by cooling the rest gas with a water spray, in which case the rest gas accounts for some of the NOx reduction and the water spray for the rest.

Comments

  1. Respected sir, i'm an oiler who done marine fitter course before gp rating, I have 2 years(24months) of Experience through Article of agreement, is the sea service for NCV MEO Class4 counted on the basis of Article or by the propulsion
    Count, sry for asking this question in this comment box there was no place for any questions...
    Thank you

    ReplyDelete
  2. Great Blog! This post gives a better idea about NOx. Thanks for the useful information. I hope you will share some more content. Please keep sharing! nitrogen gas cylinder

    ReplyDelete
  3. Thank you for providing me with such valuable information. This article provided me with some useful knowledge about air motor for sale Continue to make posts like this. Keep up the good work.

    ReplyDelete
  4. Great post and great blog, many thanks for the idea here

    Mitsubishi Xpander Bekas Murah

    ReplyDelete
  5. Great tips for us, thanks you. I also have this news Situs Spesial

    ReplyDelete

Post a Comment

Popular posts from this blog

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.  The comp

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

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 through the