Robust Gas Turbine Design

Author(s):  
Bernard Becker

Industrial gas turbines utilize numerous design features that cannot be implemented in jet aircraft turbines for weight reasons, but because of their straight-forward and robust nature trim costs and reduce both maintenance effort and operating risks. Regardless of manufacturer, the following design features, for example, have become the established industry standard: • single-shaft rotor; • 2 bearings at atmospheric pressure; • Journal bearing instead of ball bearings; • steel blading in the compressor. For the key components compressor, turbine, rotor, and combustion chamber of its 3A family (Fig. 1), Siemens has developed and tested additional features that reduce wear further and improve operational reliability. Operating experience gathered to date has shown that these features enable achievements of very high reliability and availability. Some of the measures described also contribute to enhanced output and efficiency.

Author(s):  
Tatsuo Fujii ◽  
Takakazu Uenaka ◽  
Hitoshi Masuo

The first Kawasaki-ABB GT13E2 gas turbine began operating at Kawasaki Gas Turbine Research Center (KGRC) in Sodegaura city, Japan in January 1994. This facility is a simple-cycle power station and is operated in DSS (Daily Start and Stop) operation mode as a peaking unit, and its output electricity is delivered to Tokyo Electric Power Company (TEPCO). The GT13E2 gas turbine at KGRC was manufactured jointly by Kawasaki Heavy Industries (KHI) and Asea Brown Boveri (ABB). KHI and ABB have a joint test program with this facility to research for high reliability, high performance and low emission for the GT13E2 and future gas turbines. The performance of the KGRC GT13E2 has been monitored continuously. It was found from these monitored data that the thermal efficiency has been maintained at a high level and could be recovered by compressor washing when the compressor was fouled. Several factors which influence NOx emissions were studied on the gas turbine, and it was found that atmospheric humidity has a major influence on NOx emissions. Also other factor such as the position of the variable inlet guide vanes (VIGV) and fuel gas flow through each burner of the combustor were adjusted to reduce NOx emission. As a result, NOx emission from the KGRC GT13E2 has been maintained at a very low level. Reliability, availability and maintainability (RAM) has been evaluated by Operational Reliability Analysis Program (ORAP®) of Strategic Power Systems, Inc. (SPS) in order to identify and improve RAM performance of the GT13E2 at KGRC. These analyses made it clear what kind of outage had an impact on the reliability, availability and starting reliability of the KGRC GT13E2 and appropriate actions have increased the starting reliability. This paper describes operating experiences of the KGRC GT13E2 including performance, emissions and RAM performance.


Author(s):  
S. C. Knowles

The development of the letter code desk is described, particular reference being made to the necessity for the characteristics to be suited to the operating personnel. An explanation is given of the design features introduced as a result of this unit being required in relatively large numbers for this class of work. The development of the special printing unit for code application is described, with particular emphasis on the very high reliability required. An indication is given of probable future trends.


1980 ◽  
Author(s):  
T. W. Temple ◽  
F. L. Foltz ◽  
H. R. Jamalallail

The 747-mile East-West Crude Oil Pipeline across Saudi Arabia employs 60 gas turbines for pumping and power generation. Mainline pump drives are three United Technologies Corporation FT4A-9 modular industrial gas turbines at each of 11 pumping stations. Two of the three mainline gas turbines are required for maximum throughput, while the third is an operational spare. High reliability and availability constraints and the remote unmanned station concept underscore the need for a modern maintenance information system. This paper describes an independent multiple-fault diagnostic/prognostic system, employing a patented gas path analysis technique.


Author(s):  
R. J. Antos ◽  
W. C. Emmerling

One common method of reducing the NOx emissions from industrial gas turbines is to inject water into the combustion process. The amount of water injected depends on the emissions rules that apply to a particular unit. Westinghouse W501B industrial gas turbines have been operated at water injection levels required to meet EPA NOx emissions regulations. They also have been operated at higher injection levels required to meet stricter California regulations. Operation at the lower rates of water did not affect combustor inspection and/or repair intervals. Operation on liquid fuels with high rates of water also did not result in premature distress. However, operation on gas fuel at high rates of water did cause premature distress in the combustors. To evaluate this phenomenon, a comprehensive test program was conducted; it demonstrated that the distress is the result of the temperature patterns in the combustor caused by the high rates of water. The test also indicated that there is no significant change in dynamic response levels in the combustor. This paper presents the test results, and the design features selected to substantially improve combustor wall temperature when operating on gas fuels, with the high rates of water injection required to meet California applications. Mechanical design features that improve combustor resistance to water injection-induced thermal gradients also are presented.


Author(s):  
Pritee Purohit ◽  
Shashikant T. Vagge

This chapter describes how for power generators like gas turbines and aero engines, the economic and environmental challenges are increasing day by day for producing electricity more efficiently. The efficiency of power generators can be increased by changing its operating conditions like inlet temperature and procedure. Currently, the inlet temperature to the industrial gas turbine is reaching up to 1400°C. Also, in aero engines, the ring temperature reaches around 1550°C. Therefore, the coatings used in aero engine applications undergo short duration thermal cycles at very high temperature. The mean metal temperatures reach around 950°C and can increase up to 1100°C. But in industrial gas turbines, it varies from 800 to 950°C. Operating temperature of industrial gas turbines slowly reaches to maximum and ideally remains constant for thousands of hours, unlike aero engines.


Author(s):  
Valentina Zaccaria ◽  
Mario L. Ferrari ◽  
Konstantinos Kyprianidis

Abstract Microgas turbine (MGT) engines in the range of 1–100 kW are playing a key role in distributed generation applications, due to the high reliability and quick load following that favor their integration with intermittent renewable sources. Micro-combined heat and power (CHP) systems based on gas turbine technology are obtaining a higher share in the market and are aiming at reducing the costs and increasing energy conversion efficiency. An effective control of system operating parameters during the whole engine lifetime is essential to maintain desired performance and at the same time guarantee safe operations. Because of the necessity to reduce the costs, fewer sensors are usually available than in standard industrial gas turbines, limiting the choice of control parameters. This aspect is aggravated by engine aging and deterioration phenomena that change operating performance from the expected one. In this situation, a control architecture designed for healthy operations may not be adequate anymore, because the relationship between measured parameters and unmeasured variables (e.g., turbine inlet temperature (TIT) or efficiency) varies depending on the level of engine deterioration. In this work, an adaptive control scheme is proposed to compensate the effects of engine degradation over the lifetime. Component degradation level is monitored by a diagnostic tool that estimates performance variations from the available measurements; then, the information on the gas turbine health condition is used by an observer-based model predictive controller to maintain the machine in a safe range of operation and limit the reduction in system efficiency.


1993 ◽  
Author(s):  
Jacek Misiowiec ◽  
Tim McElwee ◽  
Sal DellaVilla

Gas turbine design evolution and practice is driven by industry demand for increased output and improved operating efficiencies. New aerothermal design characteristics require a focus on improved materials and coatings, and cooling techniques. As environmental issues continue to confront the industry, Dry Low NOx combustion system designs represent a significant opportunity for meeting new emissions requirements. These issues represent opportunity for significant technology improvements and industry driven advances. However, just as important is the design evolution of the Control and Auxiliary systems which support the gas turbine. Historically, these support systems, as demonstrated by the Operational Reliability Analysis Program (ORAP), are typically the primary drivers of plant Availability and Reliability. Following a rigorous “Design for Reliability” approach provides opportunities for ensuring that the design meets three critical requirements: starting reliability, a minimum of unit shutdowns during operating demand periods and ease of maintenance. The design approach for the Control and Auxiliary systems for new turbine design (product improvement) therefore provides an opportunity for developing a uniform and standardized approach which continues to focus on Reliability, Availability, and Maintainability. This design approach also provides opportunities for improved field installation and reduced cycle time, a major benefit for the end user. This paper will describe the “Design for Reliability” approach followed by ABB Power Generation, Inc., and supported by Strategic Power Systems, Inc.® (SPS) for the GT11N2 auxiliary systems. The extension of the ORAP system for auxiliary systems will be discussed as the approach for monitoring unit Availability and Reliability, maintaining configuration control, and for promoting continuous improvement.


Author(s):  
Julie McGraw ◽  
Reiner Anton ◽  
Christian Ba¨hr ◽  
Mary Chiozza

In order to promote high efficiency combined with high power output, reliability, and availability, Siemens advanced gas turbines are equipped with state-of-the-art turbine blades and hot gas path parts. These parts embody the latest developments in base materials (single crystal and directionally solidified), as well as complex cooling arrangements (round and shaped holes) and coating systems. A modern gas turbine blade (or other hot gas path part) is a duplex component consisting of base material and coating system. Planned recoating and repair intervals are established as part of the blade design. Advanced repair technologies are essential to allow cost-effective refurbishing while maintaining high reliability. This paper gives an overview of the operating experience and key technologies used to repair these parts.


Author(s):  
Chris Waldhelm ◽  
Peter Baron

Application of gas turbines in the off-shore oil and gas market has been successful for many years, utilizing both industrial gas turbines, as well as, aeroderivative types. Today, many operators in this market are pursuing the use of converted oil tankers and purpose-built barges — called Floating Production Storage and Off-Loading vessels (FPSO) — and semi-submersible or tension-leg platforms as alternative means of drilling for and production of oil and gas in much deeper waters than before, gaining flexibility of operation and reduced overall costs. Due to the special requirements of extreme conditions experienced on board a FPSO vessel, each application involves a considerable amount of pre-design to determine the gas turbine package required capability to satisfy needed reliability. Additionally, international and local maritime regulatory bodies and classification societies concurrence/approval generally are required to authorize vessel operation. The intent of the “Code of Construction and Equipment of Offshore Drilling Units” is to recommend design criteria, construction standards, and other safety measures in order to minimize risk to the vessels, platforms, personnel and to the environment. To incorporate these requirements into a standardized cost effective gas turbine system, this paper outlines the design features of such a package for installation on FPSO vessels.


Author(s):  
J. P. Cullen

The paper outlines the operating and maintenance experience of the TYPE H industrial gas turbines on 2 of the platforms in the Greater Ekofisk field on the Norwegian continental shelf. Traditional preventive maintenance procedures based on elapsed fired hours are discussed. Availability and reliability statistics are presented. Typical component replacement on inspections is tabulated and comments are given. Finally the author describes an on line, computer supervised, condition monitoring system which is being used and will help replace traditional preventive maintenance with predictive maintenance.


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