Introduction to Industrial Gas Turbines

Short Courses– Introduction – Thermodynamics/Brayton Cycle etc. – Gas Turbine Components and Performance – Gas Turbine Package Systems – Applications for Industrial Gas Turbines: • Upstream/Midsteam • Power Gen, LNG, etc – Maintaining Performance • Inlet Air /Fouling • Water Washing • Fuel (Gas, Liquid) – Testing – Question

METS2 Short Course 6

Short Cours

Gas Turbine Performance and Maintenance

TutorialsIn this tutorial, we will address the basic characteristics of each of the components in a gas turbine (compressor, combustor, gas generator turbine, power turbine) and the impact of typical control limits and control concepts. The power and efficiency characteristics of a gas turbine are the result of a complex interaction of different turbo machines and a combustion system The goal is to provide explanations for the operational characteristics of typical industrial gas turbines, emphasizing the interaction between the gas turbine components. The concept of component matching is explained. Methods are introduced that allow the use of data for trending and comparison purposes. The impact of component degradation on individual component performance, as well as overall engine performance is discussed, together with strategies to reduce the impact of degradation, and to maintain the high performance levels of the engine. Fuel types, and typical issues arising from the use of certain fuels , as well as the importance of appropriate gas turbine inlet air filtration are addressed. The concepts developed will be used to derive basic principles for successful condition monitoring and performance testing of gas turbines

Pulsation Amplitude Effects Of Altering Characteristics Of Gas-Liquid Dampeners

Lectur

Gas Compressor Station Economic Optimization

When considering gas compressor stations for pipeline projects, the economic success of the entire operation depends to a significant extent on the operation of the compressors involved. In this paper, the basic factors contributing to the economics are outlined, with particular emphasis on the interaction between the pipeline and the compressor station. Typical scenarios are described, highlighting the fact that pipeline operation has to take into account variations in load

Tutorial on Centrifugal Compressor Surge Control

TutorialFor every centrifugal compressor installation, the design of the surge control system is vitally important to prevent damage of the compressor internal components, seals, and bearings. While most surge control systems are capable of preventing surge for steady-state operation, emergency shutdowns (ESDs) are particularly challenging, since the surge control system must respond faster than the deceleration rate of the train. This tutorial explores various aspects of compressor surge including steady state and transient operation

GAS TURBINE PACKAGING OPTIONS AND FEATURES

TutorialThis tutorial provides an overview of typical packaging options for gas turbines in industrial applications. Applicable standards are discussed. The requirements for different systems, such as air filtration, and fuel systems are explained. Off shore requirements, especially on floating systems are highlighted

IMPACT OF PIPING IMPEDANCE AND ACOUSTIC CHARACTERISTICS ON CENTRIFUGAL COMPRESSOR SURGE AND OPERATING RANGE

LectureThe performance of a centrifugal compressor is usually defined by its head versus flow map, limited by the surge and stall regions. This map is critical to assess the operating range of a compressor for both steady state and transient system scenarios. However, the compressor map does not provide a complete picture on how the compressor will respond to rapid transient inputs and how its surge behavior is affected by these events. Specifically, the response of the compressor to rapid transient events, such as single or multiple (periodic) pressure pulses, is also a function of the compressor’s upstream and downstream piping system’s acoustic response and impedance characteristics. This unique response phenomenon was first described in the 1970s and came to be known as the “Compressor Dynamic Response (CDR) Theory”. CDR Theory explains how pulsations are amplified or reduced by a compression system’s acoustic response characteristic superimposed on the compressor head-flow map. Although the CDR Theory explained the impact of the nearby piping system on the compressor surge and pulsation amplification, it provided only limited usefulness as a quantitative analysis tool, mainly due to the lack of computational numerical tools available at the time. To fully analyze pulsating flows in complex centrifugal compressor suction and discharge header piping systems, the principles of the CDR should be implemented in a dynamic flow model to quantify the magnitude of the amplifications of pressures pulses near the surge region. When designing centrifugal compressor stations within a transmission piping system, it is critically important to have a full understanding of the impact of the station’s piping system on compressor dynamic behavior. For example, if a compressor system’s piping impedance amplifies the suction side pulsations, the compressor’s operating range will be severely limited and will produce unacceptable discharge piping vibrations. Whereas it is usually desirable to limit the downstream volume between the compressor discharge and 3rd Middle East Turbomachinery Symposium (METS III) 15-18 February 2015 | Doha, Qatar | mets.tamu.edu Copyright © 2015 by Turbomachinery Laboratory, Texas A&M Engineering Experiment Station the check valve to reduce the potential for transient surge events, a small discharge volume results in high piping impedance. This will amplify pressure pulsations passing through the compressor. The small downstream volume provides limited ability for any transient peak (such as a pressure pulse) passing through the compressor to be absorbed quickly, and an amplified discharge pressure spike will be the result. Also, if any periodic pressure excitation from upstream vortex shedding or any other continuously varying flow disturbance couples with a pipe resonance length, the result can be high fluctuations of the compressor operating point on its speed line, effectively resulting in a reduced operating range and higher than expected surge margin (surge line moves to the right). Both acoustic resonance and system impedance are functions of pipe friction, pipe and header interface connections, valve/ elbow locations, pipe diameter, valve coefficients, i.e., the entire piping system connected to the compressor. Thus, a careful acoustic and impedance design review of a compressor station design should be performed to avoid impacting the operating range of the machine. This paper describes the methodology of such a design review using modern pulsation analysis software. Examples and parametric studies are presented that demonstrate the impact of system impedance and piping acoustics on the dynamic operating response of the compressor in a typical compressor station. Some recommendations to reduce the risk of pulsation amplification and unsteady operation are also provided

INLET FOGGING AND OVERSPRAY IMPACT ON INDUSTRIAL GAS TURBINE LIFE AND PERFORMANCE

LectureThe usage of an industrial inlet fogging and overspraying system on a 35,000 hp frame type industrial gas turbine in high pressure gas reinjection service was aimed to provide additional shaft power output and improved efficiency. However, operating experience has shown less than anticipated power increase and almost no efficiency change, while the gas turbines have experienced more rapid degradation. Consequently, a detailed study was undertaken to identify the principal degradation mechanisms and quantify their relative influence on the gas turbine’s performance and life reduction. This study included a field assessment; review and analysis of the installation and operating data from the historical trend monitoring system; inspection of a rotor for fouling, corrosion, and pitting; materials analysis of the fouling deposits, rotor surface pitting, and inlet filter media; review of the function and effects of inlet fogging and overspray; assessment of the effectiveness of the current on-line/ off-line compressor washing program and its compatibility with the overspraying operation; and an analysis of the overall gas turbine efficiency to determine levels of performance degradation. Results from Copyright © 2013 by Turbomachinery Laboratory, Texas A&M University this study identified the principal gas turbine degradation mechanisms, such as blade erosion, corrosion, fouling tip clearance widening, their causes, and their relative influence on the overall performance. For example, the study showed that the total power and efficiency degradation of the unit exceeded ten percent at the time of the rotor overhaul which is well above what is expected for this type of gas turbine. About 70 percent of this degradation was due to blade erosion and rotor clearance widening. These were attributed to the water overspray operation of the gas turbines. Surface fouling and pitting also contributed about 20 percent to the total performance degradation. For the given site conditions, the fogging and overspray system provided a gas turbine performance boost of approximately 2-5 percent in power and less than 0.5 percent in efficiency. Of this performance gain, saturation fogging accounted for about 85 percent, while overspray only provided 15 percent. The principal findings of this study showed that, while the fogging worked, the performance degradation due to water overspray negated most performance gains after only about 24,000 hours of operation. More detailed findings are included in the paper

Turbomachinery Overview for Supercritical CO2 Power Cycles

Tutoria