Analysis Of IGCC Gas Turbine Performance Based On Field Data

Integrated Gasification Combined Cycle(IGCC) is a complex thermal system, which operating condition is affected by various issues. The gas turbine is one of the key components of the cycle. To predict the performance of the gas turbine, a mathematical model has been established to analyze the impact of the load, the ambient temperature, the syngas LHV and the turbine outlet temperature on the performance of gas turbine by combining with the gas turbine theory and analyzing the characteristics of the gas turbine component based on field data. Analysis results can be helpful instructions to ensure the safety of the unit. The main contents are as follows:As the load increases, the flame temperature increases, NOx emissions goes up according to the increasing NOx formation reaction rate. The liner wall’s temperature decreases a little and then increases rapidly. When the load exceeds the design point, the compressor pressure ratio may exceeds the high limited value at the risk of surge, the temperature of the turbine first stator vane is higher than the design point value, which may influence the service life, the bond coat and the liner wall are at the risk of erosion.As ambient temperature decreases, the compressor IGV is sensitive to the ambient temperature change and the pressure ratio decreases rapidly. When ambient temperature is less than the design point, the bond coat and the liner wall temperature are higher than the design point, at the risk of erosion. As ambient temperature increases, the combustor flame and the NOx emission decreases. When the ambient temperature exceeds 35℃, IGV opening could not handle the pressure ratio and the inlet air mass flow efficiently.When syngas LHV increases, the turbine inlet temperature and blade temperature keep stable. IGV opening changes only 2.8% to keep the pressure ratio stable in case of surge. The combustor flame temperature and the NOx emission increases a little caused by the syngas LHV and composition. When LHV is more than 8 MJ/kg, the bond coat is at the risk of erosion while the liner wall is cooled effectively.As turbine outlet temperature increases, the turbine cooling effect is growing worse. The cooling air mass flow in the combustor is decreasing from 515℃ to 530℃ and then suddenly increases because of the decreased opening angle of the second flow area when the turbine outlet temperature is around 530 ℃ and then decreases as the outlet temperature increases. The flame temperature, NOx emission and the equivalence ratio will rise at first, then crush down and rise at last. When the turbine outlet temperature is between 525℃ and 530℃, the NOx emission is beyond the design point value and increasing continually, the liner wall and the bond coat are at the risk of erosion.