• Title/Summary/Keyword: Piping vibration

Search Result 171, Processing Time 0.026 seconds

Thermal Expansion Measurement of Turbine and Main Steam Piping by Using Strain Gages in Power Plants (스트레인게이지를 활용한 발전소 터빈 및 주증기 배관의 열팽창 측정)

  • Na, Sang-Soo;Chung, Jae-Won;Bong, Suk-Kun;Jun, Dong-Ki;Kim, Yun-Suk
    • Proceedings of the KSME Conference
    • /
    • 2000.04b
    • /
    • pp.886-891
    • /
    • 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.

  • PDF

Vibration Reduction Method for Discharge Line of Moisture Separator Reheater (습분분리재열기 배수관 진동저감방안)

  • 이준신;손석만;김태룡
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.05a
    • /
    • pp.688-694
    • /
    • 2001
  • The 84m discharge line of moisture separator reheater(MSR) in Kori-2 had been suffered by excessive vibration from the beginning of power generation. In 1993, a complementary measure was taken to reduce the vibration level by adding several supports in the MSR pipeline. However, the piping vibration was beyond the allowable limit and an appropriate countermeasure was required to prevent the fatigue failure of the pipeline from the abnormal vibration. In this study, the vibrational characteristics of MSR pipeline and the countermeasure for abnormal vibration was investigated. Among the several vibration reduction methods, piping layout change by smoothing the pipeline was applied to the MSR pipeline in Kori-2. Applying the countermeasure, the vibration level was found to dramatically reduce from 17cm/sec to l.0cm/sec at the full-power operation condition.

  • PDF

Frequency-Dependent Element Matrices for Vibration Analysis of Piping Systems (배영계의 진동해소를 위한 주파수종속 요표행렬)

  • 양보석;안영홍;최원호
    • Journal of Ocean Engineering and Technology
    • /
    • v.6 no.2
    • /
    • pp.125-132
    • /
    • 1992
  • This paper presents an approach for the derivation of frequency-dependent element matrices for vibration analysis of piping systems containing a moving medium. The dynamic stiffness matrix is deduced from transfer matrix, and, in turn, the frequency-dependent element matrices are derived. Numerical examples show that method gives more accurate results than those obtained using the conventional static shape function based element matrices.

  • PDF

Dynamic Stability and Response Analysis of Piping System with Internal Flow (내부에 유체가 흐르는 파이프계의 동적안정성 및 응답해석)

  • 이우식;박철희;홍성철
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.15 no.6
    • /
    • pp.1861-1871
    • /
    • 1991
  • In this study, the piping system conveying unsteady flow is considered. The effects of coupling between the pipe motion and the velocity and pressure of fluid are included for the dynamic stability and response analysis of the piping system. The dynamic equations for a piping system are derived by Newtonian dynamics. For the momentum and continuity equations, the concept of moving control volume is applied. Thus, the governing equations derived herein are valid for the applications to the vibration problems occurred when a piping system starts up or shuts down and also when the valves and pumps operate. For a simply supported straight pipe, the stability analysis is conducted for various nondimensional parameters. The dynamic responses, in both stable and unstable region of stability chart, are numerically tested by the use of central difference method.

The Vibration Characteristic of Large Main Steam Pipelines in Power Plant (발전소의 대형 주증기배관의 진동 특성)

  • Kim, Yeon-Whan;Lee, Hyun
    • Journal of KSNVE
    • /
    • v.6 no.6
    • /
    • pp.709-715
    • /
    • 1996
  • In recent years, the piping vibration in many Power Plants is being increased by the aged generating facilities due to a long time use. Generally, the pressure fluctuations associated with the flow-induced excitations in this case are broadband in nature. Mainly, the dominant sources of vibration are a vortex-shedding, plane waves and boundary layer turbulence. The peak level of the spectrum is proportional to the dynamic head. A severe disturbance in pipeline results in the generation of intense broadband internal sound waves which can propagate through the piping system. The characteristic frequencies of operating loads of 20%, 57%, 70%, 100% are 4 - 6 Hz and coincide with the results from impact hammering test and FEM analysis. We chose the wire energy absorbing rope restraint as a vibration reduction method after reviewing the various conditions such as site, installing space and economic cost etc. After installation, the vibration level was reduced about 54% in velocity.

  • PDF

Experimental Study on the Noise Reduction of Drainage Pipe by a kind of Curve Pipe (곡관 종류에 따른 배수관내의 소음 저감에 관한 실험적 연구)

  • Kim, Jeong-Hoon;Shim, Dong-Hyouk;Kim, Kyoung-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.11a
    • /
    • pp.187-192
    • /
    • 2006
  • The effect where the multiple sound arrest ing goes mad to the human being does the zone. From like that cotton, this dissertation the both sides flag executed the research regarding a sound arresting reduction in the object in one example. It compared the piping structure which generally is space-time and a specific piping structure and it tested and research and the modeling regarding a sound arresting reduction the simulation which leads and it executed result and comparison of existing it analyzed. The duplication where the reduction effect is bigger the result general VG2 piping structure than escape it did with the fact that it appears the large effect the piping structure which it connects. Also, the straight pipe effect of multiple sound arresting could not go mad with the fact that.

  • PDF

A Study on the Vibration Responses of Piping Systems by Pulsation Flow (맥동류에 의한 파이프 계의 진동응답에 관한 연구)

  • Lee, Dong-Myung;Choi, Myung-Jin
    • The Journal of the Acoustical Society of Korea
    • /
    • v.16 no.6
    • /
    • pp.68-75
    • /
    • 1997
  • In this study, to investigate vibration response of piping systems due to pulsation flow, a transfer matrix method is presented. Fluid-pipe interaction is formulated using wave equation for flow velocity and pressure, which depends on position and time. From the wave equation, transfer matrix is obtained. The dynamic responses of piping systems induced by pulsation flow appeared to depend upon fluctuation fluid velocity and pressure occurrnece from pulsation, and beating phenomena were observed near the resonance. Consequently, the dynamic behaviors of piping systems appeared to the same as response characteristics of the inside flow pattern of the pipe, and are determined by the inside fluid flow.

  • PDF

Design of the Wire Rope Type Snubber for Earthquake and Vibration of Piping System (Wire Rope형 배관 지진$\cdot$진동완충기의 설계)

  • 김영중
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 1998.10a
    • /
    • pp.173-179
    • /
    • 1998
  • The piping system of a power plant suffers not only thermal expansion according to the temperature variation, but also many kinds of load: steady state vibrations due to the equipment operation or fluid flow, and transient vibrations due to the earthquake or explosion, etc. The snubbers are usually installed on the piping system to allow thermal expansion, and to reduce dynamic responses. Most snubbers are kinds of hydraulic and mechanical type, which can be degraded by leakage and abrasion, and required much cost for maintenance and replacement. Recently the wire rope type snubbers are developed and applied to the power plant, and proved as effective to reduce piping system vibration. Wire rope type snubber uses the bending rigidity and energy dissipation properties of ropes. This paper presents the procedure of design, and the method to apply hysteresis curve to the dynamic response analysis. Experiments were also conducted to confirm design results.

  • PDF

A research on Dynamic characteristic of Submerged pipe ; Support, Flange, Upper pump (수위변화에 따른 파이프 시스템의 진동 특성 변화에 대한 연구)

  • Jung, Hwee Kwon;Kim, Jong Yoon;Park, Gyuhae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2013.10a
    • /
    • pp.699-705
    • /
    • 2013
  • This paper presents vibration testing, control, and finite element analysis of a piping system, which is subjected to the changes in fluid levels. Nuclear power plants typically employ a cooling system that uses sea water. These systems are subjected to dynamic characteristic changes caused by sea-level variations, which introduces failures of cooling system components. Therefore in this study, analytical and experimental studies were performed to understand the effect of sea-level changes on the dynamic characteristics of piping systems. It was shown that, as the sea-level increases, pipe's natural frequencies decreases in relation to its mode shape. A 1/14 scale model was also built to compare the results obtained by the analytical study. A good agreement between experiment and analytical studies were observed. Finally, an on-line resonant frequency identification system was proposed and developed, which utilizes piezoelectric transducers as sensors and actuators, in order to avoid catastrophic failure of piping systems.

  • PDF

Non-contact monitoring of 3-dimensional vibrations of bodies using a neural network

  • Ha, Sung Chul;Cho, Gyeong Rae;Doh, Deog-Hee
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.39 no.10
    • /
    • pp.1011-1016
    • /
    • 2015
  • Gas piping systems in power plants and factories are always influenced by the mechanical vibrations of rotational machines such as pumps, blowers, and compressors. Unusual vibrations in a gas piping system influence possible leakages of liquids or gases, which can lead to large explosive accidents. Real-time measurements of unusual vibrations in piping systems in situ prohibit them from being possible leakages owing to the repeated fatigue of vibrations. In this paper, a non-contact 3-dimensional measurement system that can detect the vibrations of a solid body and monitor its vibrational modes is introduced. To detect the displacements of a body, a stereoscopic camera system is used, through which the major vibration types of solid bodies (such as X-axis-major, Y-axis-major, and Z-axis-major vibrations) can be monitored. In order to judge the vibration types, an artificial neural network is used. The measurement system consists of a host computer, stereoscopic camera system (two-camera system, high-speed high-resolution camera), and a measurement target. Through practical application on a flat plate, the measured data from the non-contact measurement system showed good agreement with those from the original vibration mode produced by an accelerator.