An Analysis of Power Enhancement of Gas Turbine Power Plant Using Different Types of Air Cooling System

Gas Turbines are constant volume machines and their power output is directly proportional and limited by the air mass flow rate entering the turbine. The increase in ambient temperature can results in decrease of air density, and consequently in the reduction of the mass flow rate. Thereby mass flow rate of air passes through the turbine and power output is reduced especially in summer months. This is a major negative aspect of gas turbines operating in a tropical country like India. Karaikal is a major port city of East Coast of India where this study was carried out, where the ambient temperature typically varies between 28C and 38C. In this study the performance enhancement of Puducherry power Corporation power plant located in karaikal, Union Territory of Pondicherry Gas turbine is thermodynamically analyzed by suggesting cooling the compressor intake air with different type of cooling methods. There are two basic systems currently available for inlet cooling. The first and most common system used in Gas turbine inlet air cooling is evaporative cooling system. The second system involves application of absorption type chiller to cool the inlet air before entering in to the axial flow compressor. In the present work, a thermodynamic analysis of gas turbine performance is carried out to calculate compressor work, power output and thermal efficiency at different inlet air temperature condition. The cooled air being denser gives the machine a higher mass flow rate, resulting in an increase in turbine output and efficiency. After the application of above two methods of cooling system, the corresponding results are compared and finally arrived as the absorption type cooling system for inlet air is most suitable for prevailing atmospheric condition of karaikal region.