Allocate u per to the balancing correction planes based on rotor configuration. The methods employed in shop balancing can have a profound impact on the resulting balance condition of the rotor. For this reason, gas turbine rotors are among the most difficult objects to balance. Applications of an interactive balancing procedure for gas. The lp rotors have three balance planes and generators have facilities to attach balance weights in almost any axial position.
Highspeed turbine rotor balancing lowers costs and. A number of technological and scientific advances through the ages have helped us reach the standard of living we enjoy today. Assembled aircraft gas turbine rotors flywheels pump impellers machinetool and general machinery parts medium and large electric armatures of electric motors having at least 80 mm shaft height without. One of the most important was the development of antifriction bearings. Pdf practical balancing of flexible rotors for power. Wide range of service products offering comprehensive support from ad hoc call out, risk and reward, bespoke customer tailored and full level 2 or 3 ltsa ltp maintenance contract cover. Ge lm5000 gas turbine this section describes an interactive balancing experience of a ge lm5000 gas turbine installed in a power generation facility. In 1985, papers were presented at vibration institute meetings on the dynamic analysis and field balancing of 70 mw gas turbine generator systems. A method of balancing an assembly of rotary parts of a gas turbine engine 10 comprising measuring at least one of the concentricity and parallelism of each component and considering globally all possible component stacking positions to generate an optimized stacking position for each component of the assembly to minimize assembly unbalance. Excitations of the rotor train by imbalance forces are a common cause of increased vibrations of. Us9206692b2 gas turbine rotor assembly balancing method. Dynamic analysis and field balancing of 70 mw gasturbine.
Method of balancing a gas turbine engine rotor pratt. Each of the machine trains bearing is monitored by displacement transducers mounted on the machine casing in a plane xy perpendicular to the rotor axis of the machine to observe radial motion of the shaft. Machine train consist of a generator and aero derivative turbine. After repeated rotor balancing simulations, it was concluded that assembly balancing using the influence coefficient technique was costeffectiveand prac tical for the t700 power turbine rotor. Ep2019185a2 method of balancing a gas turbine engine. Rotors are classified as being either rigid or flexible. Vibration literature1 can be obtained for study in more technical detail. Trim balancing is done at gas turbine balance planes in the forward and aft sections of the gas turbine. Balancing, rotor, vibration, influence coefficient, exact point. Coupling and balance planes in gas turbinecompressor train. Potential failure modes hot gas path components gas turbine component life diagram with key factors assembly turbine operation outage assembly turbine operation outage assembly repair workscope repair workscope stores stores. The article contains excerpts from the paper, rotor balancing tutorial by ray kelm, dustin pavelek and walter kelm of kelm.
Dynamic analysis and field balancing of 100 mw utility gas. We use influence coefficient balance methods, which offer the best assurance of. If a rotor is balanced on a low speed balancing machine assuming it is rigid and then in service becomes flexible, then unbalance and thus high vibration, will be the result. Ger4212 ge generator rotor design, operational issues.
Proceedings of the asme 1979 international gas turbine conference and exhibit and solar energy conference. Dynamics of rotating machinery with case studies balancing fundamentals critical speeds and vibratory modes how to identify and understand its significance. Our secure customer login 9fa gas turbine provides seamless access to your ge information and assets. Joe corcoran is the global manager of services and training for kopflex, regal beloit corporation, in. The machine is a gas turbine with a 2000 lb rotor consisting of an axial. Typical machines, which fit this category, include steam and gas turbines. One the threshold is exceeded, automatic trip of turbine takes place. A combustion chamber or area, called a combustor, in between 1. It can be checked by rolling the rotor on horizontal knifeedge supports.
Performing step 1 simply requires the user to find the rotor type that most nearly describes the one. Balancing these aspects of the power plant management requires consideration of the oem recommendations as well as the knowledge, expertise and technology available from independent engineering service providers. The gas turbine proper has 5 balancing planes, at the first stage of the axial compressor, between the 6th and 7th stages, two. Figure 3 shows a crosssection of the 70 mw gas turbine showing the balance planes. The rotordynamic behavior of an industrial gas turbine rotor train was assessed on site, and the sensitivity to unbalance was quantified. The incremental rotor balancing procedure turbomachinery. Corcoran manager, global services and training kopflex, regal beloit hanover, maryland joseph p. The gas initially drives the liquid hydrogen pump turbine, then it is further expanded to feed the liquid oxygen turbopump turbine. At turbine efficiency, we use a schenck approved rotor balancing machine. Ger4212 ge generator rotor design, operational issues, and. Shop balancing methods the methods employed in shop balancing can have a profound impact on the resulting balance condition of the rotor.
May 28, 2017 the methods employed in shop balancing can have a profound impact on the resulting balance condition of the rotor. In 1985, papers were presented at vibration institute meetings on the dynamic analysis and field balancing of 70 mw gas turbinegenerator systems. Highspeed balancing hsb of generator and turbine rotors offers a number of advantages. A fourth component is often used to increase efficiency turboprop. T700 power turbine rotor multiplane multispeed balancing. Mar 16, 2017 in one aspect, there is provided a method of balancing a gas turbine engine rotor, the method comprising. Typical hp and ip turbines are provided with two balance planes. In general, long and slender rotors are the most wellsuited for a high speed balance, but any rotor that has the aforementioned repairs or problems can benefit from high speed balancing. This limit is established in general by the capabilities of shop balance machines. Power generation high speed rotor balance toshiba america.
A rigid rotor is one whose ser vice speed is less than 50% of its first critical speed. Above 600 rpm rotor relative vibrations should be monitored. In order to balance gas turbine engines, transmission gears, and helicopter drive shafting, the. In one aspect, there is provided a method of balancing a gas turbine engine rotor, the method comprising. Pdf practical balancing of flexible rotors for power generation. Advanced vibration analysis to root cause finding for industrial rotary equipment with the help of modern instruments. Dynamic analysis and balancing of an aircraft gas turbine dyrobes. The vibration data indicated erratic behavior as well as a three times super. Gas turbine manufacturers specify that the rotating element of a gas turbine has a limited life based on the number of fired hours run and the number of starts. Balance quality requirements of rigid rotors ird balancing. Dynamic analysis and balancing of an aircraft gas turbine by. Highspeed turbine rotor balancing was once rare because of the costs and logistical challenges involved in doing it during an outage.
Performing onsite balance for a variety of rotary equipment. The axial compressor is attached to the gas turbine by a bolted flange assembly. Pdf this paper deals with some of the challenges in the dynamic analysis and field balancing of the w501d gas turbinegenerator system. The gas turbine has 17 axial compressor stages and 4 gas turbine stages.
Thats begun to change as economic options emerge, and. The real values of critical speeds should be measured at. Iso standards for machine vibration and balancing focus on large. Methods of assembling a rotor assembly of a gas turbine engine having a plurality of components.
High speed balancing of turbine rotor at 3000 rpm at dyna mech duration. Dedicated rotor balancing facility rotor balance facility utilising a schenk. Pdf dynamic analysis and field balancing of 100 mw. Reducing shaft vibrations generally reduces bearing loads and increases the service life. It is recommended, depending on the make and model of the gas turbine, that a rotor life assessment inspection be performed on the rotor every 100,000 to 200,000 hours. As a result, the actual balance condition of an assembled rotor is never fully known prior to.
It is important to understand the various causes of the rotor dynamic characteristics and the vibration signatures experienced by the gas turbine. The engine extracts chemical energy from fuel and converts it to mechanical energy using the gaseous energy of the working fluid air to drive the engine and propeller, which, in turn, propel the airplane. The solution to the problem is to balance each stage separately before assembling it in the rotor. For builtup rotors, each bladed disc is balanced individually prior to assembly.
To calculate the balancing tolerances, the following formula can be used. Turbine rotors that have had significant blade repairs. The epri rotor program has developed technology and methods to offer an integrated approach to gas turbine rotor condition. A flexible rotor will require multiplane balancing. Turbine blade measurement by a new moment balance machine. Ge power systems ger4212 0801 2 ge generator rotor design, operational issues, and refurbishment options coupling coil slot retaining ring balance plug fan collector. Static balance means that the weight is evenly disposed around the axis of the shaft. Ep2019185a2 method of balancing a gas turbine engine rotor. Highspeed turbine rotor balancing lowers costs and improves. The impact of shop balance technique is most important when the rotor is relatively flexible andor long as is common with most turbomachinery. The objective of balancing is to reduce shaft vibration to a practical minimum. Dynamics of rotating machinery with emphasis on balancing technical services 2. A photograph of the turbine on a stand is shown in fig.
Optimal component stacking positions, among other things, may then be. Above this speed, the rotor is said to be flexible. Differential data reduction with test unbalances was undertaken to minimize the influence of measurement uncertainty. Rotor balancing and fullspeed noload test of the 9fa gas turbine is usually performed in the factory before shipment. The method comprises, in one aspect, determining a static unbalance force of each component using the mass and the center of mass location, and determining an optimum assembly arrangement minimizing static unbalance forces. These include smooth operation, access to optimal weight planes, and verification of the mechanical integrity of the rotor and any assembled components rotors are typically run to 110% overspeed. The task of balancing each stage can be simplified if the blades are assembled in the hub. A new simulation process for the life management of the. Ge generator rotor design, operational issues, and refurbishment options.
Ge generator rotor design, operational issues, and refurbishment options contents. Gas turbine repair technology ge power systems ger3957b 0401 2 table 3. Should site vibration levels exceed those specified, provision is made for site trim balancing on the lp rotors via access holes in each gland housing. Application notes static and dynamic balancing of rigid. Mar 22, 2011 a method of balancing a rotor assembly of a gas turbine engine, the engine having a first rotor pack comprising a plurality of assembled rotor components and a spigot coupling interface for telescopic connection to a mating spigot of a second rotor pack, the method comprising.
Then multiply e per by rotor weight to obtain the permissible residual unbalance, u per. A method of balancing a rotor assembly of a gas turbine engine, the engine having a first rotor pack comprising a plurality of assembled rotor components and a spigot coupling interface for telescopic connection to a mating spigot of a second rotor pack, the method comprising. The following table gives the balancing grade for various types of rotors. A gas turbine, also called a combustion turbine, is a type of continuous combustion, internal combustion engine. When assembled with blades, the rotor is balanced both statically and dynamically. Matthew smillie, consultant engineer, quest integrity group. The rotor dynamic characteristics in presentday gas turbines and especially in advanced gas turbines are very critical and must be fully understood. Sep 25, 2017 mhi compressor international high speed balancing. The weightsaving concepts employed in the design of the turbine rotor assembly resulted in a weight reduction of of, of. Over speed test and fullload rejection tests are 9fa gas turbine at customer site.
The successful nature of the analytical balancing simulation results allowed mti to demonstrate the actual balancing. Mhi compressor international high speed balancing youtube. This application note is concerned with rigid rotors only. Laser balancing demonstration on a highspeed flexible rotor. Practical balancing of flexible rotors for power generation. Since our founding, weve enjoyed a reputation as innovators, practitioners and teachers in the art of balancing and vibration analysis of heavy rotating equipment. The article contains excerpts from the paper, rotor balancing tutorial by ray kelm, dustin pavelek. Sgt100, sgt200, sgt300, gas generators and power turbines. Rotors that have had their journals, couplings or fits machined. We use influence coefficient balance methods, which offer the best assurance of reliable results. Vibration measurement techniques on an industrial gas. Highspeed rotors often require fieldbalancing trim balancing at full speed to make adjustments for rotor deflection and final bearing stiffness and damping conditions. Fundamentals of gas turbine engines introduction the gas turbine is an internal combustion engine that uses air as the working fluid.
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