Gas Turbine Fogging Technology: A State-of-the-Art Review—Part I: Inlet Evaporative Fogging—Analytical and Experimental Aspects

Abstract

Ambient temperature strongly influences gas turbine power output causing a reduction of around 0.50% to 0.90% for every 1°C of temperature rise. There is also a significant increase in the gas turbine heat rate as the ambient temperature rises, resulting in an increased operating cost. As the increase in power demand is usually coincident with high ambient temperature, power augmentation during the hot part of the day becomes important for independent power producers, cogenerators, and electric utilities. Evaporative and overspray fogging are simple, proven, and cost effective approaches for recovering lost gas turbine performance. A comprehensive review of the current understanding of the analytical, experimental, and practical aspects including climatic and psychrometric aspects of high-pressure inlet evaporative fogging technology is provided. A discussion of analytical and experimental results relating to droplets dynamics, factors affecting droplets size, and inlet duct configuration effects on inlet evaporative fogging is covered in this paper. Characteristics of commonly used fogging nozzles are also described and experimental findings presented.