Gas Turbine Fouling: A Comparison Among 100 Heavy-Duty Frames

Abstract

Over recent decades, the variability and high costs of the traditional gas turbine fuels (e.g., natural gas) have pushed operators to consider low-grade fuels for running heavy-duty frames. Synfuels, obtained from coal, petroleum, or biomass gasification, could represent valid alternatives in this sense. Although these alternatives match the reduction of costs and, in the case of biomass sources, would potentially provide a CO2 emission benefit (reduction of the CO2 capture and sequestration costs), these low-grade fuels have a higher content of contaminants. Synfuels are filtered before the combustor stage, but the contaminants are not removed completely. This fact leads to a considerable amount of deposition on the nozzle vanes due to the high temperature value. In addition to this, the continuous demand for increasing gas turbine efficiency determines a higher combustor outlet temperature. Current advanced gas turbine engines operate at a turbine inlet temperature (TIT) of (1400–1500) °C, which is high enough to melt a high proportion of the contaminants introduced by low-grade fuels. Particle deposition can increase surface roughness, modify the airfoil shape, and clog the coolant passages. At the same time, land-based power units experience compressor fouling, due to the air contaminants able to pass through the filtration barriers. Hot sections and compressor fouling work together to determine performance degradation. This paper proposes an analysis of the contaminant deposition on hot gas turbine sections based on machine nameplate data. Hot section and compressor fouling are estimated using a fouling susceptibility criterion. The combination of gas turbine net power, efficiency, and TIT with different types of synfuel contaminants highlights how each gas turbine is subjected to particle deposition. The simulation of particle deposition on 100 gas turbines ranging from 1.2 MW to 420 MW was conducted following the fouling susceptibility criterion. Using a simplified particle deposition calculation based on TIT and contaminant viscosity estimation, the analysis shows how the correlation between type of contaminant and gas turbine performance plays a key role. The results allow the choice of the best heavy-duty frame as a function of the fuel. Low-efficiency frames (characterized by lower values of TIT) show the best compromise in order to reduce the effects of particle deposition in the presence of high-temperature melting contaminants. A high-efficiency frame is suitable when the contaminants are characterized by a low-melting point thanks to their lower fuel consumption.

A methodology for identifying the most suitable measurements for engine level and component level gas path diagnostics of a micro gas turbine

“…Comparison of these values with the deviation of the related parameters (see Table 4, Figures 6 and 7), shows that variation of Witalicnet under all fault cases, variation of truemf˙ under the CF, CE, and TF, variation of Po2 under the CF, and CE variation of To6 under the RF is considerably larger than the noise level. Consequently, observation of mentioned variation is feasible through related available measurement.…”

“…Equations ( 6) and (7) show the recuperator effect on the compressor exit air temperature and pressure before entering the burner. 31 T o5 ¼ e � T o4 � T o2 ð Þþ T o2 (6)…”

“…The gas turbine components degradation is an unavoidable event in the effect of the challenging operating conditions. 5–7 Fouling and erosion are the main factors of gas turbine components degradation. These factors may lead to performance loss, the Turbine Inlet Temperature (TIT) rise, and the reduction of the safe operating range of gas turbines.…”

“…[2][3][4] The gas turbine components degradation is an unavoidable event in the effect of the challenging operating conditions. [5][6][7] Fouling and erosion are the main factors of gas turbine components degradation.…”

Analyzing Gas Turbine Performance Through Simulation and Performance Tests: Case Study of Gas Turbine Units in Jambi, Indonesia

“…Gas turbines have gained increasing popularity in recent years due to their high efficiency, reliability, and flexibility [1]. They are used in various applications, such as power generation, aviation, and industrial processes [2]. Gas turbines also serve as ideal equipment to balance variable renewable energy sources such as wind and solar in power systems, given their ability to rapidly adjust power output [3], [4].…”