How Does VIT Control Nox Emissions

How Does VIT Control Nox Emissions

Get to know about how Variable Injection Timing controls the Nox Emissions

in the Marine Diesel Engines.

Variable Injection Timing is among some of the methods which are used to

improve the engine performance, plus improves the Nox Emissions from the

engine. Very important as per the new Marpol regulations.

How To Control Nox Emissions

As we know that to reduce the Nox emission the combustion temperature is

the key. Lower the temp lesser the emission. By using VIT we can adjust the

beginning of the injection as well as the end of the injection. So we try to inject

fuel before TDC. So, that we can get the peak pressure at a much lower load

than MCR, which we call as CSR.

By running the engine at lower load with the maximum peak pressure we can

have a better SOFC, better combustion efficiency and more or less a complete

combustion. Lesser chance of after burning (if no dribbling of injector). And

more time for expansion cycle to occur. These all factors affect the NOx

emission.

Here are some of the ways to achieve lower temperatures inside combustion

space.

Reduce the cylinder temp. But peak pressure and fuel consumption will

increase.

Using fuel water emulation, 1% water adding, but specific fuel oil

consumption will be increased.

Water injection, on exhaust side which is called humidification.

Exhaust gas recirculation.

Increasing scavenge pressure.

By catalytic converter