Gas Turbine Life Limiting Effects Of Inlet And Interstage Water Injection.
Power enhancement technologies for gas turbines such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection are being used by end users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Specifically, the effect of these add-on devices, off-design operating conditions, nonstandard fuels, and compressor degradation/fouling on the gas turbine’s axial compressor surge margin and aerodynamic stability is often overlooked. However, aerodynamic axial compressor instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure. A careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses nonstandard fuels. This paper discusses a simple method to assess the major factors that affect the aerodynamic stability of a single shaft gas turbine’s axial compressor. As an example, the method is applied to a frame type gas turbine, and the results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities, but it can be a contributing factor if, for other reasons, the machine’s surge margin is already slim. The approach described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure.
Interstage Injection System for Heavy Duty Industrial Gas Turbine Model 7EA
This paper describes new methods of cleaning large multistage axial compressors that are the part of Gas Turbine Unit (GTU). Existing, standard method of compressor cleaning are on-line and off-line. In both cases of compressor cleaning clean water and appropriate detergents are mixed to remove dirt deposits from the blade surface. The on-line system is attractive because the cleaning is done when GTU is under full load. The on-line compressor cleaning slows down inevitable dirt depositing. Offline cleaning is much more effective than on-line cleaning. The negative side of off-line cleaning is that GTU must be shut down. In case of large GTU the processes of shut down and start up require significant amount of time. This paper also incorporates the efforts required to install Inter-stage Injection System (IIS) in one GTU in Watson Cogeneration Company (WCC).Copyright © 2001 by ASME
DEM generation from new VIR sensors: IKONOS, ASTER and Landsat-7
DEM generation is a living R&D topic since new-launched satellite images can be used to generate stereoscopic images. Using a coplanarity equation model developed at CCRS and an automatic matching method developed at PCI, DEMs are generated with new VIR stereo data. Accuracy of 4.9 m with high-resolution IKONOS images, and 33 m and 101 m with medium-resolution ASTER and Landsat-7 ETM/sup +/ images respectively are obtained. The same matching accuracy of one-pixel is translated into worse results with Landsat due to a small B/H ratio of 0.15.