Improving Gas Turbine Performance Using Mechanical Chiller: A Thermodynamic Approach

The improvement in gas turbine power plants by integrating a mechanical chiller to it for cooling the inlet air is the prime objective of this study. The bucket cooling method adopted in this study to cool the turbine buckets has been chosen as film cooling. The selected input parameters have been varied to analyze the power plant output and efficiency at varying conditions and then select the best alternative which will help the design engineers. The integration of mechanical chiller significantly augments the plant output and efficiency. This improvement is more pronounced in hot and humid climates. It was observed that as the compressor inlet temperature is reduced the bucket coolant mass flow rate decreases and the mass of fuel energy input increases. The increase in specific work and efficiency is calculated to be 14.59 % and 4.46 % respectively when the ambient temperature drops to 283K. The work ratio increases with increase in value of ratio of inlet temperatures (rIT) upto 5.6 after which it starts decreasing. There is an optimum rIT at any pressure ratio (rp,c.)at which the work ratio is maximum. The heat rate increases with increase in rIT and decrease in rp,c..