• Title, Summary, Keyword: 시스템다이나믹스

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A Study on Repair Case of Journal and Bearing Damage for 25MW Industrial Gas Turbine (25MW급 산업용 가스터빈의 저널과 베어링 손상 보수사례에 관한 연구)

  • Kim, Byung Ok;Sun, Kyung Ho;Lee, An Sung
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.6
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    • pp.64-69
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    • 2012
  • This paper deals with the study on repair case of journal shaft and bearing damage in 25MW industrial gas turbine caused by sudden blackout, operation mistake, and logic abnormal, etc. When a serious accident such as journal and bearing damage in a gas turbine occurs, the domestic local companies having the gas turbine are dependent on manufacturer for all maintenance and repair schedule until now. This case study shows that the damaged gas turbine is normally re-operated itself in domestic by establishing repair schedule in a short period of time, repairing damage journal shaft and tilting pad bearings, and performing rotating test for a reliability check. This paper can be regarded as the important case study of emergency test run experience of the refurbished 25MW gas turbine rotor.

Design of Hybrid Mount to Naval Shipboard Considering Shock Resistance (내충격 성능을 고려한 함정용 하이브리드 마운트의 설계)

  • Jo, Hye-Young;Shin, Yun-Ho;Moon, Seok-Jun;Jung, Woo-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.102-107
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    • 2012
  • In this study, the design procedure of hybrid active mount by an electro-magnetic actuator is proposed to reduce the transmitted force from naval shipboard equipment to ship hull structure. The hybrid type mount which is composed of a passive rubber element and an electro-magnetic actuator is introduced and, through the vibration measurement for the objective pump system, the required force of the actuator is computed and discussed in detail. The initial designs were supposed for three types, one is moving coil type actuator and the others are moving permanent magnet type actuators. Based on the initial design concept, the final designs considering shock resistance and interference with mover and stator are proposed and examined.

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Wind Turbine Performance for Eigen Value Change of Pitch Controller (피치제어기의 고유치 변화에 따른 풍력발전기의 성능)

  • Kim, Jong-Hwa;Moon, Seok-Jun;Shin, Yun-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.337-343
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    • 2012
  • NREL(National Renewable Energy Laboratory) Baseline controller conduct using method proposed RISO National Laboratory in Region 3. which designed the blade-pitch control system using a single degree-of-freedom model of the wind turbine. Idealized PID-Controlled rotor-speed error will respond as a second-order system with the natural frequency and damping ratio. RISO proposed specific natural frequency(=0.6 rad/s) and damping ratio(=0.7). If specific Eigen value apply to NREL 5 MW wind turbine, differ with pitch respond for simulation results of RISO report. Variation of specific eigen value investigate performance of NREL 5 MW wind turbine.

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Thermohydrodynamic Analysis and Pad Temperature Measurement of Tilting Pad Journal Bearing with Worn Pad (표면이 마모된 틸팅 패드 저널베어링의 열윤활 해석 및 온도 측정)

  • Lee, Donghyun;Sun, Kyungho;Kim, Byungock;Kang, Donghyuk
    • Tribology and Lubricants
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    • v.33 no.4
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    • pp.134-140
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    • 2017
  • With the increase in adoption of tilting pad journal bearings (TPJBs), various failure mechanisms related to TPJBs have been reported, of which pad wear is a frequently reported one. Pad wear causes change in geometry of the bearing, which can sometimes result in the failure of the entire system. The objective of this research is to investigate the influence of pad wear on the pad temperature, which is one of the widely used condition monitoring methods for TPJBs. For the theoretical investigation, thermohydrodynamic (THD) analysis was conducted by solving the generalized Reynolds equation and the 3D energy equation. The results of the analysis show that the temperature of the loaded pad increases while that of the unloaded pad decreases, when there is wear on the loaded pads. In addition, the minimum film thickness decreases with an increase in the wear depth. A validation test was conducted with a test rig, which mimics the axial turbine when a test rotor is supported by two TPJBs. The test bearing consists of five pads with a diameter of 60 mm, and a resistance temperature detector (RTD) is installed in the pad for temperature monitoring. The test was performed by replacing the two loaded pads with the worn pad. The test result for the TPJB with wear depth of $30{\mu}m$ show that the temperatures of the loaded pads are $8^{\circ}C$ higher and that of the unloaded pad is $2.5^{\circ}C$ lower than that of the normal TPJB. In addition, the predicted pad temperature shows good agreement with the measured pad temperatures.

Output feedback stabilization of planar systems with uncertainty (불확실성을 갖는 2차원 비선형 시스템의 출력 궤환 안정화)

  • Seo, Sang-Bo;Shim, Hyung-Bo;Seo, Jin-Heon
    • Proceedings of the KIEE Conference
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    • pp.1511-1512
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    • 2008
  • 본 논문에서는 불확실성을 가지는 2차원 비선형 시스템을 안정화하기 위해서 추가 다이나믹스를 이용하여 출력 궤환 제어기법을 제안한다. 추가 다이나믹스는 이득값에 대한 것으로 0으로 수렴하는 구조를 지니고 있으며, 이 상태변수의 역수가 고이득의 역할을 함으로써 불확실성이 존재함에도 불구하고 제어목표를 이룰 수 있다. 더욱이 추가 다이나믹스는 그 설계에 의해 목표달성 후에는 본래의 초기값으로 복귀하는 구조를 지니고 있다.

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Development of Shipboard Large-sized Low-noise Room Unit with Multiple Outlets (다수의 출구를 가진 선박용 대형 저소음 룸유닛 개발)

  • Kim, Sang-Ryul;Kim, Hyun-Sil;Lee, Sung-Hyun;Park, Keun-Hyo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.5
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    • pp.468-473
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    • 2012
  • In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlets. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.

Development of shipboard large-sized low-noise room unit with multiple outlets (다수의 출구를 가진 선박용 대형 저소음 룸유닛 개발)

  • Kim, Sang-Ryul;Kim, Hyun-Sil;Lee, Sung-Hyun;Park, Geun-Hyo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.600-605
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    • 2012
  • In this paper, the acoustic performance of a shipboard large-sized room unit is studied. The room unit is a kind of rectangular absorptive chamber with a partition whose surface absorptive material with fabric skin is attached to. The room unit has one inlet and three outlet. At the inlet, a plane damper is installed to control the flow rate. The acoustic performance of a prototype room unit is measured using a HVAC mock-up. It is shown that its insertion loss is comparable with that of a commercially-used room unit but the developed room unit generates flow noise higher than the other one. The major source of flow noise is analyzed by NADS-R, the noise analysis program for room unit. Cone-shaped dampers are proposed to be used as the damper of a room unit to reduce flow noise. It is shown that the cone-shaped damper decrease flow noise remarkably.

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