Vibration Control of a Gas Turbine-Generator Rotor in a Combined Cycle System by Means of Active Magnetic Bearings

Author(s):  
Rafael Pilotto ◽  
Rainer Nordmann
Author(s):  
David J. Olsheski ◽  
William W. Schulke

Traditionally commercial marine propulsion needs have been met with direct drive reciprocating prime movers. In order to increase efficiency, simplify installation and maintenance accessibility, and increase cargo / passenger capacity; indirect electric drive gas and steam turbine combined cycle prime movers are being introduced to marine propulsion systems. One such application is the Royal Caribbean Cruise Line (RCCL) Millennium Class ship. This commercial vessel has two aero-derivative gas turbine generator sets with a single waste heat recovery steam turbine generator set. Each is controlled by independent microprocessor based digital control systems. This paper addresses only the gas turbine control system architecture and the unique safety and dynamic features that are integrated into the control system for this application.


Author(s):  
Bruno Wagner

This paper recalls the principles and main features of the active magnetic bearings and especially the advantages for turbomachines. Oil-free working and vibration control are part of them. Field experiences are described for different shaft line configurations. Step by step we are going to get totally rid of oil with the introduction of active magnetic bearings together with dry gas seals and gearless drive. Future machines will take the benefit of all this field experience. The trend of the design optimization is the active magnetic bearings in the process gas itself, for a length reduction of shafts. But at the present stage, the active magnetic bearing is a proven technology today.


Author(s):  
Isaac Shnaid

The modem combined cycle power plants achieved thermal efficiency of 50–55% by applying bottoming multistage Rankine steam cycle. At the same time, the Brayton cycle is an attractive option for a bottoming cycle engine. In the author’s US Patent No. 5,442,904 is described a combined cycle system with a simple cycle gas turbine, the bottoming air turbine Brayton cycle, and the reverse Brayton cycle. In this system, air turbine Brayton cycle produces mechanic power using exergy of gas turbine exhaust gases, while the reverse Brayton cycle refrigerates gas turbine inlet air. Using this system, supercharging of gas turbine compressor becomes possible. In the paper, thermodynamic optimization of the system is done, and the system techno-economic characteristics are evaluated.


1993 ◽  
Vol 5 (5) ◽  
pp. 438-442 ◽  
Author(s):  
Nobuyoshi Taguchi ◽  
◽  
Takakazu Ishimatsu ◽  
Takashi Shimomachi ◽  
◽  
...  

Active magnetic bearings have several advantages over conventional mechanical and fluid bearings. However, when the magnetic bearings are used at high rotational speeds, whirling motions and vibrations synchronized with the rotation of the rotor should be considered. In order to suppress these unfavorable vibrations of rotor which is supported by magnetic bearings, we have developed an active vibration control system with a two-level control structure. Experimental results show that our active bearings system effectively suppresses the whirling motion.


2015 ◽  
Vol 2015.21 (0) ◽  
pp. _20420-1_-_20420-2_
Author(s):  
Hirokazu Tomono ◽  
Tasuku Kamekawa ◽  
Hiroyuki Fujisaki ◽  
Masamitsu Shiga ◽  
Toru Watanabe ◽  
...  

Author(s):  
Colin F. McDonald

With the capability of burning a variety of fossil fuels, giving high thermal efficiency, and operating with low emissions, the gas turbine is becoming a major prime-mover for a wide spectrum of applications. Almost three decades ago two experimental projects were undertaken in which gas turbines were actually operated with heat from nuclear reactors. In retrospect, these systems were ahead of their time in terms of technology readiness, and prospects of the practical coupling of a gas turbine with a nuclear heat source towards the realization of a high efficiency, pollutant free, dry-cooled power plant has remained a long-term goal, which has been periodically studied in the last twenty years. Technology advancements in both high temperature gas-cooled reactors, and gas turbines now make the concept of a nuclear gas turbine plant realizable. Two possible plant concepts are highlighted in this paper, (1) a direct cycle system involving the integration of a closed-cycle helium gas turbine with a modular high temperature gas cooled reactor (MHTGR), and (2) the utilization of a conventional and proven combined cycle gas turbine, again with the MHTGR, but now involving the use of secondary (helium) and tertiary (air) loops. The open cycle system is more equipment intensive and places demanding requirements on the very high temperature heat exchangers, but has the merit of being able to utilize a conventional combined cycle turbo-generator set. In this paper both power plant concepts are put into perspective in terms of categorizing the most suitable applications, highlighting their major features and characteristics, and identifying the technology requirements. The author would like to dedicate this paper to the late Professor Karl Bammert who actively supported deployment of the closed-cycle gas turbine for several decades with a variety of heat sources including fossil, solar, and nuclear systems.


1979 ◽  
Author(s):  
L. F. Fougere ◽  
H. G. Stewart ◽  
J. Bell

Citizens Utilities Company’s Kauai Electric Division is the electric utility on the Island of Kauai, fourth largest and westernmost as well as northernmost of the Hawaiian Islands. As a result of growing load requirements, additional generating capacity was required that would afford a high level of reliability and operating flexibility and good fuel economy at reasonable capital investment. To meet these requirements, a combined cycle arrangement was completed in 1978 utilizing one existing gas turbine-generator and one new gas turbine-generator, both exhausting to a new heat recovery steam generator which supplies steam to an existing steam turbine-generator. Damper controlled ducting directs exhaust gas from either gas turbine, one at a time, through the heat recovery steam generator. The existing oil-fired steam boiler remains available to power the steam turbine-generator independently or in parallel with the heat recovery steam generator. The gas turbines can operate either in simple cycle as peaking units or in combined cycle, one at a time, as base load units. This arrangement provides excellent operating reliability and flexibility, and the most favorable economics of all generating arrangements for the service required.


Author(s):  
J. P. Zanyk

A review of the development and use of the gas turbine generator unit in The Dow Chemical Company for the cogeneration of steam and electric power energy for Dow’s major chemical complex. This review highlights the success and problems of Dow Chemical’s most recently constructed power plant at its Texas Division in Freeport, Texas. A review of Dow’s experience and developed technology to provide a reliable cogenerating plant.


Author(s):  
W. B. Crouch ◽  
W. G. Schlinger ◽  
R. D. Klapatch ◽  
G. E. Vitti

A proposed system is presented for low pollution power generation by means of a combined cycle gas turbine system using low Btu fuel gas produced from high sulfur residual oil and solid fuel. Experimental results and conclusions are presented from a cooperative research program involving Texaco Inc. and Turbo Power and Marine Systems, Inc. whereby high sulfur crude oil residue was partially oxidized with air to produce a 100 to 150 Btu/scf sulfur-free fuel gas for use in a turbine combustor. An FT4 gas turbine combustion chamber test demonstrated that low Btu gas can be efficiently burned with a large reduction in NOx emissions. Gas turbine modifications required to burn low Btu gas are described and projected NOx emission compared to No. 2 fuel oil and natural gas are shown for an FT4 gas turbine. Integration of the gas turbine combined cycle system to a low Btu gasification process is described. The system provides an efficient method of generating electrical power from high sulfur liquid fuels while minimizing emission of air and water pollutants.


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