Performance Improvement of Gas Turbine With Compressed Air Injection for Low Density Operational Conditions

Abstract

Gas Turbines are an important contributor to the world’s power generation at base and peak load conditions, and this participation is expected to last for the decades to come, even with the increasing use of renewable energies given their unique ability to supply large amounts of power in a short period of time (unlike coal or nuclear plants). On the other hand, the power produced by gas turbines is significantly reduced at higher ambient temperatures, which coincides with the peak power demand. Air density is reduced, either as consequence of high elevation above the sea level, or due to higher ambient temperatures, and the air mass flow passing into a gas turbine diminishes consequently. With this flow down, the fuel flow is reduced proportionately in order to maintain combustion temperature, reducing, in turn the power generation. This paper presents a parametric evaluation of a novel power enhancement scheme: intercooled compressed air injection, with performance simulations of a “F” class industrial gas turbine in a 1×1 combined cycle application made with Thermoflow GTPro and GTMaster ® software. Results show that compressed air injection achieves significant levels of power boost at heat rates better than those of simple cycle power plants, resulting in an attractive option for power-starved utilities during summer days.