Augmentation of Energy, Exergy and Emission Performance of Gas Turbine Engines Used for Ship Propulsion

Majority of prime movers for ship propulsion used currently are diesel engines mainly because of their elevated efficiency and their ability to run on residual oil. But in view of the increasing awareness for pollution control and stricter environmental regulations, gas turbine cycle can be regarded as a suitable alternative to propel large ships for cargo and military purpose. However during summer and in hot and humid climates, an increase in ambient temperature and ambient relative humidity is observed to adversely affect the performance of gas turbine (GT). In such circumstances, integration of inlet air cooling to GT cycle can be considered as a suitable alternative. The present paper discusses the possibility of using a vapor absorption inlet air cooled gas turbine cycle as a prime mover for marine application. A parametric study of the effect of compressor pressure ratio, turbine inlet temperature, ambient relative humidity and ambient temperature on energy, exergy and exhaust emission performance of film air cooled gas turbine cycle used in marine application has been carried out. Vapor absorption inlet cooling integrated to cooled gas-turbine cycle has been observed to improve the power output by 19 % and efficiency by 7.6 %. Inlet air cooling has also been observed to improve emission performance with lower NO_X, UHC and CO emission. It is further reported that the relative gain in GT work of absorption inlet air-cooled gas turbine cycle over the one without inlet air cooling is more pronounced at higher ambient temperature and lower ambient relative humidity. The integration of vapor absorption inlet air cooling system has also been observed to enhance exergy efficiency and lower exergy destruction of the gas turbine cycle.