Wartsila, Marioff To Cooperate On Emission Control Technolgy
Wartsila and Marioff, agreed earlier this year to cooperate within the area of emission control technologies for reciprocating engines. Marioff is a specialist in creating humidity, while Wartsila needs humidity for reduction of NOx in diesel, and perhaps gas engines.
The introduction of water into the combustion space of a diesel engine in one way or another reduces NOx formation. There are two main mechanisms for this phenomenon, one being the addition of mass in the combustion space. The other effect may be evaporation of the water in the combustion space during combustion. Both mechanisms are utilized in the Direct Water Injection system, which is one of the technologies promoted by Wartsila.
However, these technologies cannot be used for very low NOx, because the evaporation of the water in the combustion space will steal some of the combustion energy. For the lowest NOx values it is therefore desirable to go another way, and that is to evaporate the water before it enters the combustion space. Wartsila created such a system in the 1980s called Combustion Air Humidification. At that time it was not possible to add very much water into the combustion air due to sensitive cylinder liner piston ring technology. Since the introduction of the antipolishing ring diesel engines have been virtually insensitive to humidity in the combustion air, Wartsila decided to take up the development of this system again. Here the Marioff technology to create very small water droplets, HI-FOG, comes in handy because when water is introduced directly after the turbocharger in an environment of more than 200 degrees C and more than 75 m/s air velocity, the small water droplets will evaporate fast.