Benefits of Compressor Inlet Air Cooling for Gas Turbine Cogeneration Plants

Abstract

Compressor inlet air cooling is an effective method for enhancing the performance of gas turbine plants. This paper presents a comparative analysis of different solutions for cooling the compressor inlet air for the LM6000 gas turbine in a cogeneration plant operated in base load. Absorption and evaporative cooling systems are considered and their performance and economic benefits compared for the dry low-NOx LM6000 version. Reference is made to two sites in Northern and Southern Italy, whose climatic data series for modeling the variations in ambient temperature during the single day were used, to account for the effects of climate in the simulation. The results confirmed the advantages of inlet air cooling systems. In particular, evaporative cooling proved to be cost-effective, though capable of supplying only moderate cooling, while absorption systems have a higher cost but are also more versatile and powerful in base load operation. An integration of the two systems proved to be able to give both maximum performance enhancement and net economic benefit.