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.

Aerodynamic limits air injection for heavy-duty gas turbine: Compressor aerodynamic limits for power augmentation and ramp-up capabilities

“…It also shows that the surge limit can be reached through air injection and can vary depending on the compressor design. In the analytical work by Quintero et al [2], air injection was deployed at lower density conditions, to restore a GT power through compressed air injection. The works of Abudu et al [3,5] shows an analytical engine-level analysis of air injection behind the compressor, for heavyduty GT and aero-derivative engines respectively.…”

“…The CAES system provides stored higher-pressure air than that of the GT maximum, to allow for air injection for power output augmentation or ramp-up rate increase. Existing research specifically on GT air injection includes [1][2][3] that covers power augmentation, and [3][4][5] that addresses the improvement of engine ramp-up rates. The previous study by Igie et al 1 indicated that it is possible to elevate the GT power output by 36% through 17.5% air injection at the back of the compressor, keeping the combustor outlet temperature (COT) fixed.…”

Efficiency Enhancement of Gas Turbine Systems with Air Injection Driven by Natural Gas Turboexpanders

“…Internal combustion engines are less sensitive to temperature and humidity, maintaining their nominal power output and efficiency over a broader range of ambient conditions. Hence, some companies designed a series of standardized building block modules which can be connected together to operate at high injection air flows [10]. Combined diesel-engine gas turbine systems enable distributed power generation plants to attain high thermal efficiencies while enjoying the operational advantages of both diesel engines and gas turbines [11].…”