• 소음진동
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• 제4권1호
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• pp.23-31
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• 1994

When a shaft is misaligned, a high level of vibration is experienced. As a consequence, the system performance could be low with high level of noise generated. Even, a catastrophic damage of the rotating machinery may happen in the worst situation. The vibration caused by the shaft misalignment is not cured unless a correct alignment of the shaft is investigated. In this paper, a step by step approach for the turbine alignment has been demonstrated. It includes measurement tips of the coupling rim and face, calculation procedure of the bearing level, and the relevant values of the addition and subtration for shims in order to align the shaft level correctly. Then, as an application of the shaft alignment, the turbine system at the Pyung Tek focile electric power plant has been examined. Since the real system consists of high pressure, low pressure turbines and the generator, detailed alignment prolcedures of the multi stage shaft system has been demonstrated.

• 열병합발전
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• 통권37호
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• pp.18-21
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• 2004

There are several bearing system at large steam-turbines in thermal power plant. The bearing system is one of the most important parts of rotating machinery. The steam turbine vibrations mainly depend on the bearing oil the shaft alignment condition. This paper describes on the steam turbine abnormal vibration due to the oil whip in terms of the shaft alignment in the thermal power plant.

• 소음진동
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• 제8권5호
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• pp.922-928
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• 1998

This paper presents the automatic alignment measuring system for improving the accuracy and working time of alignment of large vertical hydraulic pump turbine. It is general practice that rotating shaft should run within acceptable vibration limit. In order to obtain better run-out data of multi-stage rotor, careful and accurate alignment approach must be established. Generally, present alignment procedure are required several iterative works and so many manpower. Therefore, the new system has been developed using a vector calculation algorithm, laser sensor and data acquisition devices. As a result of appling to actual machines, it is confirmed that manpower is saved up to an average 90%.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1015-1019
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• 2001

There are several bearing systems at the large steam-turbines in thermal power plant. The bearing system is one of the most important parts of rotating machinery. The steam turbine vibrations mainly depend on the bearing oil and the shaft alignment condition. This paper describes on the steam turbine abnormal vibration due to the oil whip in terms of the shaft alignment in the thermal power plant.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.315-321
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• 2001

The shaft system of turbine is composed of rotating shaft, blades, bearings which support the shaft, packing seal which prevent the leakage of steam, and couplings which connect the shaft. Shaft system component failure, incorrect assemblage or deflection by unexpected forces causes vibration problem. And every turbine has its own characteristics in dynamic response. In this paper we propose the three-bearing supported type rotor which is real equipment and being operated this time as commercial operation. From 1996 it has a high vibration problem and there are many kinds of trial to solve this problem. In resent outage we performed a special diagnosis and carried out appropriate work. We would like to introduce and explain about this case history.

• Journal of Advanced Marine Engineering and Technology
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• 제5권1호
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• pp.20-27
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• 1981

The alignment of propulsion shaft systems by the fair curve method has been developed over the past twenty years and in recent years its basic problems have been almost solved. At the present time, studies on introducing actual conditions are being undertaken. In a fair curve alignment, its aim is to achieve a stable shaft system which will be relatively insensitive to misalignment or the influence of external factors such as thermal variations due to the sunshine, speed change, etc. The key point of fair curve alignment is the calculations of reactions in the straight support and reaction influence numbers. The present authors have developed those calculating method by the matrix method of the three-moment theorem. The fair curve alignment is based on the analysis of propulsion shaft system which is assumed as a continous beam on multiple support points. The propeller shaft is divided into several elements. For each element, the nodal point equation is derived by the three-moment theorem. Reaction of supporting points of straight shaft and reaction influence numbers are calculated by the matrix calculation of each nodal point equation. It has been found that results of calculation for the model shaft agree well with those of experiment which had been measured by the strain gauge method. Results of calculation for the actual propulsion shafting of the steam turbine had been compared also with those of Det norske Vertas.

• 소음진동
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• 제4권1호
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• pp.33-42
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• 1994

When a vibration is generated due to the misalignment, the reduction of the vibration level is not attainable unless a correct shaft alignment is conducted. In a turbine system, an alignment procedure requires quite a lot amount of expense and time. To reduce this effort, an algorithm of the turbine alignment is developed to be used in the computer program. The program consists of five parts : input, calculation, display of the results, file management, and printer output. In the input part, users must provide the data on the turbine number, the reference value of the alignment, and the number of the feet of the generator. In calculation, the moving distance of the bearing and the necessary amount of the shims are calculated. In the display and the output parts, the calculated results are displayed and calculated. In the display and the output parts, the calculated results are displayed and printed. Then, by using the file management, results and procedures conducted are saved in the floppy diskette or in the hard disk. The developed program can be run in IBM PC compatible with more than 640 KB of main memory with the operating system of MS-DOS v 3.3 or higher. It is developed for novice users with no experience or specialty in this field. The program is not only useful in the power plant application, but also helpful for recording of the alignment procedures.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.886-891
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• 2000

One of the domestic co-generation plants have undergone excessive vibration problems of turbine attributed to external force for years. The root cause of turbine vibration may be shan alignment problem which sometimes is changed by thermal expansion and external farce, even if turbine technicians perfectly performed it. To evaluate the alignment condition from plant start-up to full load, a strain measurement of turbine and main steam piping subjected to thermal loading is monitored by using strain gages. The strain gages are bonded on both bearing housing adjusting bolts and pipe stoppers which. installed in the x-direction of left-side main steam piping near the turbine inlet in order to monitor closely the effect of turbine under thermal deformation of turbine casing and main steam piping during plant full load. Also in situ load of constant support hangers in main steam piping system is measured by strain gages and its results are used to rebalance the hanger rod load. Consequently, the experimental stress analysis by using strain gages turns out to be very useful tool to diagnose the trouble and failures of not only to stationary components but to rotating machinery in power plants.

• 플랜트 저널
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• 제4권3호
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• pp.66-72
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• 2008

The vibration of steam turbine is caused by Mass unbalance, Shaft misalignment, Oil whip and rubbing etc. But in turbine which is normally operated and maintained, the Mass unbalance component possesses the greatest portion. Our power plant has two steam turbines in capacity of 200 MW and 135 MW respectively and each turbine is supported by 6 journal bearings. However, we had many difficulties because the vibration amplitude of #3 and #4 Bearings was high during the start-up and operation mode change of steam turbine. But, with this study, we completely solved the vibration problem caused by the mass unbalance of #1 steam turbine. Until a recent date, #3 and #4 bearings which support high pressure turbine for #1 steam turbine had shown about $135{\mu}m$ in vibration amplitude (sometimes it increased to $221{\mu}m$ maximum. alarm: 6 mils, trip: 9 mils) at base load. After applying the study, they decreased to about $45{\mu}m$ maximum. It is a result from that we did not change the setting value of bearing alignment and only changed the assembly position of internal parts in Synchro clutch coupling rachet wheel which links between high pressure turbine and low pressure turbine, and increased the internal gap and machining of the Pawl cage surface. In the operation of steam turbine, if the vibration value increases by 1X, we should reduce the vibration of bearing by weight balancing. However, unless the vibration of bearing is declined by the balancing, we will have to disassemble and check the component and find the cause. In this study, we researched the way to lower mass unbalance that is 1X vibration component which has the greatest portion of vibration generated by steam turbine and we got good result by applying the findings of this study.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.232-235
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• 2008

The vibration of steam turbine is caused by Mass Unbalance, Shaft Misalignment, Oil Whip and Rubbing etc. but in turbine which is normally operated and maintained, the Mass Unbalance component possesses the greatest portion. Our power plant has two steam turbines in capacity of 200MW and 135MW respectively and each turbine is supported by 6 journal bearings. However, we had many difficulties because the vibration amplitude of No 3 and 4 Bearings was high during the start-up and operation mode change of steam turbine. But, with this study, we completely solved the vibration problem caused by the mass unbalance of No 1 steam turbine. Until a recent date, No 3 and 4 bearings which support high pressure turbine for No 1 steam turbine had shown about 135${\mu}$m in vibration amplitude (sometimes it increased to 221${\mu}$m maximum. alarm: 6mils, trip: 9mils) at base load. After applying the study, they decreased to about 40${\mu}$m maximum. It is a result from that we did not change the setting value of Bearing Alignment and only changed the assembly position of internal parts in Synchro Clutch Coupling Rachet Wheel which links between high pressure turbine and low pressure turbine, and increased the internal gap and machining of the Pawl stopper surface. In the operation of steam turbine, if the vibration value increases by 1X, we should reduce the vibration of bearing by weight balancing. However, unless the vibration of bearing is declined by the balancing, we will have to disassemble and check the component and find the cause. In this study, We researched the way to lower mass unbalance that is 1X vibration component which has the greatest portion of vibration generated by steam turbine and We got good result by applying the findings of this study.