• Title, Summary, Keyword: Pipe Line

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Vibration Reduction of Pipe Line in Air-conditioner for Railway Vehicle (철도차량용 냉방기 배관계의 진동저감 연구)

  • You, Won-Hee;Jung, Yong-Ho;Koo, Jeong-Seo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.10
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    • pp.925-931
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    • 2012
  • The air-conditioner for railway vehicle should have vibration durability in order to operate normally in vehicle running situation. KS R 9144(vibration test methods for railway vehicle parts) is used to verify the vibration durability. The specifications of compressor, condenser and evaporator for air-conditioner in railway vehicle are standardized, but the shape and structure of pipe lines are not specified. Because the air-conditioner handler produces the pipe line arbitrarily, sometimes the pipe line is broken during the vibration durability test. In this research the cause identification and solution of pipe line breaking problem in during the vibration durability test were studied for air-conditioner of railway vehicle(diesel multiple unit). It was found that the natural frequency of pipe line is related to the pipe line breaking by experiment. A new pipe line shape was introduced by using FEA in order to avoid the resonance. The prototype new pipe line was applied to air-conditioner and the natural frequency was measured by experiment in order to verify the resonance avoidance. The vibration reduction of air-conditioner with new pipe line was reviewed by comparing to the air-conditioner with original one.

Development of Pipe Fault Inspection System using Computer Vision (컴퓨터 비젼을 이용한 파이프 불량 검사시스템 개발)

  • 박찬호;양순용;안경관;오현옥;이병룡
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.10
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    • pp.822-831
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    • 2003
  • A computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and the radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation is introduced for line detection. The dimension of inner and outer radius of pipe is calculated by the proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle, by which pipes with wrong end-shape can be classified and removed.

Analysis of a transient vibration response caused by Water Hammer in a pipe-line system (수격 현상에 의한 파이프의 과도진동응답 해석)

  • 조성문;서영수;정의봉;정호경
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.119-124
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    • 2004
  • A water hammer mostly comes out when a valve fixed at the downstream end of the pipe-line system is rapidly closed or opened. A simple phenomenon of water hammer is often caused around us, and this phenomenon imperils the pipe systems occasionally. In this paper, we confirmed the phenomenon of water hammer by an experiment and forecasted a change of pressure in the pipe-line system by a numerical method. Also a vibration response, which is caused by water hammer, of the pipe-line system confirmed by an experiment and analyzed by a numerical method.

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Evaluation of Blast Wave and Pipe Whip Effects According to High Energy Line Break Locations (고에너지배관 파단위치에 따른 배관휩과 충격파의 영향 평가)

  • Kim, Seung Hyun;Chang, Yoon-Suk;Choi, Choengryul;Kim, Won Tae
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.13 no.1
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    • pp.54-60
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    • 2017
  • When a sudden rupture occurs in high energy lines, ejection of inner fluid with high temperature and pressure causes blast wave as well as thrust forces on the ruptured pipe itself. The present study is to examine pipe whip behaviors and blast wave phenomena under postulated pipe break conditions. In this context, typical numerical models were generated by taking a MSL (Main Steam Line) piping, a steam generator and containment building. Subsequently, numerical analyses were carried out by changing break locations; one is pipe whip analyses to assess displacements and stresses of the broken pipe due to the thrust force. The other is blast wave analyses to evaluate the broken pipe due to the blast wave by considering the pipe whip. As a result, the stress value of the steam generator increased by about 7~21% and von Mises stress of steam generator outlet nozzle exceeded the yield strength of the material. In the displacement results, rapid movement of pipe occurred at 0.1 sec due to the blast wave, and the maximum displacement increased by about 2~9%.

A Study about Pipe Shape Inspection System for Computer Vision (컴퓨터 비젼을 이용한 파이프 형상 검사시스템에 관한 연구)

  • 김형석;이병룡;양순용;안경관;오현옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.946-950
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    • 2003
  • In this paper, a computer-vision based pipe shape inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle. by which pipes with wrong end-shape can be classified removed.

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Development of Pipe-Inspection System Using Computer Vision

  • Park, Chan-ho;Lee, Byungryoung;Soonyoung Yang;Kyungkwan Ahn;Hyunog Oh
    • 제어로봇시스템학회:학술대회논문집
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    • pp.99.1-99
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    • 2002
  • In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplacian operator with input image which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along t...

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A Study about Pipe inspection System for Computer Vision (컴퓨터 비젼을 이용한 파이프 검사시스템에 대한 연구)

  • 박찬호;이병룡;양순용;안경관;오현옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.521-525
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    • 2002
  • In this paper, a computer-vision based pipe-inspection algorithm is developed. The algorithm uses the modified Hough transformation and a line-scanning approach to identify the edge line and radius of the pipe image, from which the eccentricity and dimension of the pipe-end is calculated. Line and circle detection was performed using Laplace operator with input image, which are acquired from the front and side cameras. In order to minimize the memory usage and the processing time, a clustering method with the modified Hough transformation for line detection. The dimension of inner and outer radius of pipe is calculated by proposed line-scanning method. The method scans several lines along the X and Y axes, calculating the eccentricity of inner and outer circle, by which pipes with wrong end-shape can be classified removed.

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Thermal and Flow Analysis of Organic Rankine Cycle System Pipe Line for 250 kW Grade Waste Gas Heat Recovery (250kW급 폐열회수 시스템용 유기랭킨사이클 배관 열유동해석에 관한 연구)

  • Kim, Kyoung Su;Bang, Se Kyoung;Seo, In Ho;Lee, Sang Yun;Yi, Chung Seob
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.4
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    • pp.26-33
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    • 2019
  • This study is a thermal and flow analysis of Organic Rankine Cycle (ORC) pipe line for 250 kW grade waste gas heat recovery. We attempted to obtain the boundary condition data through the process design of the ORC, which can produce an electric power of 250 kW through the recovery of waste heat. Then, we conducted a simulation by using STAR-CCM+ to verify the model for the pipe line stream of the 250 kW class waste heat recovery system. Based on the results of the thermal and flow analyses of each pipe line applied to the ORC system, we gained the following conclusion. The pressure was relatively increased at the pipe outside the refracted part due to the pipe shape. Moreover, the heat transfer amount of the refrigerant gas line is relatively higher than that of the liquid line.

Pipe Offset Routing Program By Using 3D CAD For Shipbuilding (조선전용 3차원 CAD 시스템을 이용한 Pipe Offset Routing 프로그램 개발)

  • Kim, Sung-Min;Sheen, Dong-Mok
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.4
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    • pp.432-440
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    • 2008
  • Korean shipbuilders are starting to use three dimensional solid CAD systems to enhance their competitiveness in design and production. Despite many merits, three dimensional CAD systems reveal some problems in pipe-line modeling. Pipe-line modeling is heavily dependent on point data in routing. However, since the models built by sweeping or skinning operations do not have data about points and lines on the surfaces, the point data for routing are currently manually calculated by considering the diameters of the pipes and alignment conditions with other pipes. This process is inefficient and prone to errors. In order to enhance the pipe modeling, this paper presents an Offset Routing Program for a three dimensional CAD system, which aids designers to easily define the start points and to generate the pipe routings using reference objects.

Applicability of Existing Fracture Initiation Models to Modern Line Pipe Steels

  • Shim, Do Jun
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.12 no.2
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    • pp.1-24
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    • 2016
  • The original fracture criteria developed by Maxey/Kiefner for axial through-wall and surface-cracked pipes have worked well for many industries for a large variety of relatively low strength and toughness materials. However, newer line pipe steels have some unusual characteristics that differ from these older materials. One example is a test data that has demonstrated that X80 line-pipe with an axial through-wall-crack can fail at pressures about 30 percent lower than predicted with commonly used analysis methods for older steels. Thus, it is essential to review the currently available models and investigate the applicability of these models to newer high-strength line pipe materials. In this paper, the available models for predicting the failure behavior of axial-cracked pipes (through-wall-cracked and external surface-cracked pipes) were reviewed. Furthermore, the applicability of these models to high-strength steel pipes was investigated by analyzing limited full-scale pipe fracture initiation test results. Based on the analyzed results, the shortcomings of the available models were identified. For both through-wall and surface cracks, the major shortcomings were related to the characterization of the material toughness, which generally leads to non-conservative predictions in the J-T analyses. The findings in this paper may be limited to the test data that were consider for this study. The requisite characteristics of a potential model were also identified in the present paper.