15-02-2010, 01:17 PM
REDUCED EMISSIONS OF OXIDES OF NITROGEN IN SHIP ENGINES.ppt (Size: 595.5 KB / Downloads: 277)
REDUCED EMISSIONS OF OXIDES OF NITROGEN IN SHIP ENGINES
INTRODUCTION
Oxides of nitrogen emission from ship engines are significant on a global level. These emissions participate in the formation of photochemical smog and acid rain. Here we look at to some ways by which these emissions can be reduced.
Mechanism of NOx Formation in Diesel Engines.
At the temperature of the Burning of fuel spray (about 2000 K to 2500 K).
Nitrogen + Oxygen Oxides of Nitrogen
(mostly Nitric Oxide)
During expansion process and in exhaust.
Nitric Oxide NO2 and N2O
NOx Control Measures
1. Engine Tuning.
a. Intelligent Engines.
b. Injection Timing Retard.
c. Fuel Injector Valves and Nozzles.
d. Injection Rate Shaping.
e. Compression Ratio, Injection Timing and Injection Rate.
f. Scavenge Air Temperature.
2. Water Injection, Fuel/Water Emulsion, Humidification.
3. Exhaust Gas Recirculation.
4. Selective Catalytic Reaction.
CONCLUSION
Most engine manufactures are now producing standard engines. This has been achieved by engine tuning measures.