• 제목/요약/키워드: 가이드 베인

검색결과 48건 처리시간 0.037초

Evaluation of Effect of Low Opening Operation on Increasing Wear of Bearing Bushings of Guide Vanes used in Hydropower Plants (수력발전소 가이드 베인 저개도율 운전에 따른 가이드 베인 베어링 부슁의 마모 가속효과 평가)

  • Kim, Jong-Sung;Kim, Se-Na
    • Transactions of the Korean Society of Mechanical Engineers A
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    • 제36권10호
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    • pp.1267-1274
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    • 2012
  • A guide vane plays a key role in controlling the flow rate of water supplied to the turbine of a hydropower plant. It has been reported that guide vane bearing bushings are subjected to considerable wear, which requires them to be maintained. An ancillary service such as frequency control and black start causes cyclic low opening operation of the guide vanes. It is empirically well known that such operation increases the wear rate of the guide vane bearing bushing. In this study, the effect of low opening operation on the increasing wear of the guide vane bearing bushing is quantitatively assessed via finite element flow analysis, finite element stress analysis, and relative wear evaluation. As a result of the assessment, it is identified that the pressure applied on the guide vane surface increases and the contact length between the outer surface of the guide vane stem and the inner surface of the bearing bushing decreases with a decrease in the opening of the guide vane. In addition, low opening of the guide vanes results in an increase in the relative wear owing to the generation of high contact pressure on the bearing bushing surfaces.

CFD Based Shape Design of Guide Vane for Fan Filter Unit (전산유체해석을 이용한 Fan Filter Unit(FFU)의 가이드 베인 형상설계)

  • Jang, Jun Hwan;Ahn, Joon;Myong, Hyon Kook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • 제37권7호
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    • pp.709-716
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    • 2013
  • A fan filter unit (FFU) is a device which supplies clean air from the ceiling in a clean room. With an increase in its size, velocity variation occurs within the exhaust plane and this damage the product quality or productivity. Hence, a guide vane is installed inside the device to enhance the velocity uniformity. Because the vane reduces the flow rate for a given pumping power, an optimum design is required to achieve velocity uniformity while minimizing the flow rate reduction at the same time. To find a geometry that satisfies these requirements, a series of numerical simulations has been conducted while changing the angle and length of the guide vanes. By changing the geometry of the side guide vane, the velocity uniformity increased by 3.7% and the flow rate decreased by 1.5%. For the center guide vane, the velocity uniformity increased by 2.9% and the flow rate decreased by 0.7%.

Numerical Study for the Optimal Operation of Semi Dry Reactor(SDR) (SDR 반응의 운전 최적화를 위한 전산 해석)

  • Park, Ki-Woo;Jung, Yu-Jin;Jeong, Moon-Heon;Hong, Sung-Gil;Jung, Jong-Hyeon;Lim, Ki-Hyuk;Shon, Byung-Hyun
    • Proceedings of the KAIS Fall Conference
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    • 한국산학기술학회 2012년도 춘계학술논문집 1부
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    • pp.426-430
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    • 2012
  • 본 연구에서는 3차원 수치 해석 기법으로 SDR 반응기 내 유동 특성을 모사하여 유동 분포 및 체류 시간등을 확인하고 혼합 특성 개선을 위한 방법에 대해 연구하였다. 본 연구 대상 SDR 반응기는 입구 덕트와 반응기 본체의 접속 구간에 가이드 베인(Guide vane)이 설치되어 있고 그 바로 하부 지점에 흡수제를 분무하는 노즐이 설치되어 있다. 이는 처리가스가 반응기로 유입될 때 가이드 베인에 의해 선회류를 형성하여 분무된 흡수제와의 혼합을 촉진시키기 위한 목적으로 설치하였다. 시간당 1,971$m^3/min$ at $260^{\circ}C$의 처리가스가 반응기 상부로 유입되어 가이드 베인을 거쳐 선회류를 형성한 후흡수제와 혼합되어 하부로 배출되는 구조이다. 유동 특성을 분석한 결과, 처리가스가 반응기 중앙으로 강하게 편중되고 있었으며 반응기 양 측면으로 부상 기류가 형성되고 있음을 확인할 수 있다. 또한 강한 편류에 의해 체류시간도 매우 짧은 것으로 판단되는 바, 가이드 베인의 기류 안내 각도가 적합하지 못함을 확인할 수 있었다. 이는 곧 혼합 특성 저하에 따른 미반응 액적의 다량 발생과 함께 고착에 의한 스케일 형성 가능성이 매우 클 것으로 예상되므로 혼합 특성을 개선할 수 있는 설계 변경이 필요할 것으로 판단되었다. 따라서 편류를 해소하고 노즐 근처에서의 체공시간을 확보할 수 있도록 가이드 베인의 안내 각도를 더 크게 변경한 결과, 기존 설계상에서 본체 중앙에 형성되는 편류가 해소되고 선회류의 전개 각도가 커지면서 체류시간 역시 약 5초 이상으로 유지되고 있음을 확인할 수 있었다. 따라서 가이드 베인의 각도만 변경하더라도 본체 형상의 추가적인 변경없이 유동의 혼합 특성을 개선시킬 수 있을 것으로 판단되었다.

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Numerical Study on the Effect of Guide Vane Position and Angle on Heat Transfer and Flow Characteristics of a Pin-fin Channel with a Guide Vane (가이드 베인을 부착한 핀-휜 유동에서 가이드 베인 위치와 입사각에 따른 전열 및 유동 특성에 관한 수치적 연구)

  • Lee, Deukho;Oh, Yeongtaek;Bae, Jihwan;Lee, Changhyeong;Kim, Kuisoon
    • Journal of the Korean Society of Propulsion Engineers
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    • 제23권3호
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    • pp.35-43
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    • 2019
  • In this study, a guide vane with varying positions and incidence angles was adopted to a pin-fin channel to analyze the change in thermal performance and pressure loss characteristics. A numerical analysis was conducted to investigate the effect of incidence angles and positions on heat transfer and flow characteristics at Re =1400. The results of it were compared those of a pin-fin channel without a guide vane. In case 1 when the incidence angle is $0^{\circ}$, the heat transfer performance is maximized and improved by approximately 5% when compared to the pin-fin channel without the guide vane. In case 2 when the incidence angle is $10^{\circ}$, the pressure loss is minimized and decreased by approximately 1.9% when compared to the pin-fin channel without the guide vane.

Evaluation of Acceleration Effect of Ancillary Services on Cavitation and Fatigue of a Water Turbine in Pumped-Storage Plants (부수적 서비스 제공에 따른 양수발전소 수차의 캐비테이션 및 피로에 대한 가속효과 평가)

  • Kim, Jong Sung;Kim, Se Na
    • Transactions of the Korean Society of Mechanical Engineers A
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    • 제41권3호
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    • pp.225-232
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    • 2017
  • Several maintenance issues related to cavitation erosion and fatigue cracks in the water turbine subcomponents of pumped-storage plants, such as a runner and a draft tube, have been reported in the past. Generally, the pumped-storage plants provide ancillary services, such as black-start and system stabilization. The ancillary services are responsible for cyclic low opening operation of the guide vanes. It has been empirically established that this low opening operation further damages the water turbine subcomponents. In this study, the acceleration effect of the low opening operation on the cavitation erosion and fatigue of the water turbine is quantitatively assessed through finite element flow analysis, finite element stress analysis, and fatigue analysis. As a result of the assessment, it is identified that the cavitation potential increases and the turbine efficiency decreases with a decrease in the opening of the guide vane. Also, the low opening operation has an insignificant effect on the fatigue even though it increases the maximum stress values at the runner blade roots.

NUMERICAL OPTIMIZATION OF TEMPERATURE DISTRIBUTION IN HRSG SYSTEM USING INLET GUIDE VANE (전치 가이드 베인 설치에 따른 열회수 보일러 입구 온도 최적화)

  • Lee, Soo-Yoon;Ahn, Joon;Shin, Seung-Won
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 학술대회
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    • pp.148-154
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    • 2008
  • Diverging channel from gas burner exit to the inlet section of Heat Recovery Steam Generator (HRSG) has been re-designed for 1 MW system. To improve the uniformity in velocity and temperature distribution of existing design(Case A and B) of 300 kW HRSG system, two additional test geometries have been chosen for the numerical simulation. At first, gas burner exit section has been centered to the inlet section of boiler(Case C) and uniformity has been improved considerably. Secondly, the diverging channel length can be further reduced for compact geometry with new guide vane design (Case D and E). Proposed design shows overall improvement in uniformity in velocity and temperature distribution compared to existing one.

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NUMERICAL OPTIMIZATION OF TEMPERATURE DISTRIBUTION IN HRSG SYSTEM USING INLET GUIDE VANE (전치 가이드 베인 설치에 따른 열회수 보일러 입구 온도 최적화)

  • Lee, Soo-Yoon;Ahn, Joon;Shin, Seung-Won
    • Journal of computational fluids engineering
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    • 제14권3호
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    • pp.1-8
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    • 2009
  • Diverging channel from gas engine exit to the inlet section of Heat Recovery Steam Generator (HRSG) has been re-designed for 1 MW system. To improve the uniformity in velocity and temperature distribution of existing design(Case A and B), two additional test geometries have been chosen for the numerical simulation. At first, gas burner exit section has been centered to the inlet section of the boiler(Case C) and uniformity in velocity and temperature distribution has been improved considerably. Secondly, the diverging channel length can be further reduced to compact geometry with new guide vane design (Case D and E). Proposed design shows overall improvement in uniformity in velocity and temperature distribution compared to existing one.

Numerical Simulation of Duct Flow about Shape and Arrangement of Inlet Guide Vane to Increase the Temperature Uniformity (전치 가이드 베인 배치 및 형상에 따른 보일러 입구 온도분포의 수치해석 연구)

  • Lee, Su-Yun;Shin, Seung-Won
    • Proceedings of the SAREK Conference
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1172-1177
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    • 2008
  • Diverging channel from gas burner exit to the inlet section of Heat Recovery Steam Generator (HRSG) has been re-designed for 1 MW steam supply and power generation system. Three different test geometries have been chosen for the numerical simulation. The existing design for 300 kW HRSG system (CASE B) has been improved by geometry and position changes of inlet guide vanes along with gas velocity entrance angle at the diverging channel inlet (CASE C). Both cases has been compared with the case where hot combustion gas is directly injected without any guide vanes (CASE A). Improved design shows overall uniform velocity and temperature distribution compared to existing design.

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Numerical Analysis of Flows for Agricultural Dryer with Heat Pump (히트펌프를 이용한 농산물 건조기 유동 수치해석)

  • Park, Sang-Jun;Lee, Young-Lim
    • Proceedings of the KAIS Fall Conference
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    • 한국산학기술학회 2011년도 춘계학술논문집 2부
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    • pp.676-678
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    • 2011
  • 히트펌프 사이클을 이용한 건조 공정은 최종 제품의 생산을 위하여 많은 산업 분야에 요구되는 필수 공정으로 본 논문에서는 대형 히트펌프 건조기의 상부 분리대의 가이드 베인의 형상 및 수량을 최적화 하였다. 이를 위해 팬은 성능곡선 모델을 사용하였고, 증발기와 응축기는 다공성 매질로 가정하였다. 이는 팬을 통과하여 가이드 베인을 따라 건조기 입구로 들어가는 바람의 균일도를 예측할 수 있어 설계 정확도 향상에 기여할 수 있다.

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A Comparative Study on the Flow and Heat Transfer Performance Characteristics of Vortex Generators and Guide Vane in Fin-Tube (핀-튜브에서 와류 발생기와 가이드 베인의 유동 및 전열 성능 특성에 관한 비교 연구)

  • Bae, JiHwan;Oh, YeongTaek;Lee, ChangHyeong;Lee, DeukHo;Kim, KuiSoon
    • Journal of Aerospace System Engineering
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    • 제14권3호
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    • pp.1-9
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    • 2020
  • In this paper, the effects of the delta winglet vortex generator, the airfoil vortex generator and the guide vanes on the friction factor and the Colburn factor in the fin-tube flow were studied. The vortex generator and guide vane were non-dimensionalized based on the channel height and tube diameter, and locations were selected according to the authors' suggestions. The Reynolds number based on the inlet velocity and the tube diameter was selected in the range of 1400-8000. As a result, the friction factor resulted in a 4.7% decrease in guide vanes at the Reynolds number 8000 over the conventional fin-tube, and the Colburn factor resulted in a 33% increase in the delta winglet vortex generator at the Reynolds number 3800 over the conventional fin-tube.