• 한국항공우주학회지
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• 제34권4호
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• pp.70-75
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• 2006

액체로켓용 터보펌프의 설계과정에서 정확한 성능예측을 위해서 인듀서, 임펠러, 볼류트, 실 등의 펌프의 모든 부분을 포함한 유동해석을 수행하였다. 계산시간을 줄이기 위해서 인듀서와 임펠러는 주기조건을 사용하여 하나의 블레이드 통로만 해석하였으며, 인듀서와 임펠러, 임펠러와 볼류트 등의 상호작용은 정상적 해석법인 혼합면 기법을 사용하였다. 펌프의 모든 부분을 포함한 계산을 통하여 인듀서, 임펠러, 볼류트 등의 단독 유동해석을 통해서는 예측할 수 없는 펌프설계의 매우 중요한 부분인 축추력 등을 예측할 수 있었으며, 각 부품이 전체 성능에 미치는 영향을 자세히 파악할 수 있었다. 계산결과를 실험결과와 비교하였는데, 양정, 효율, 볼류트 외벽 압력분포 등에서 실험결과와 잘 일치하였다. 또한 실험으로 검증하지는 못하였지만, 축추력, 반경방향 힘 등의 예측값도 설계요구조건을 만족시키는 것으로 나타났다. 따라서 펌프의 전부분을 포함한 유동해석법은 터보펌프의 설계 및 성능예측에 매우 유용하게 적용될 수 있을 것으로 판단된다.

• 대한기계학회논문집B
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• 제40권11호
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• pp.727-736
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• 2016

본 연구에서는 복합화력 화력 발전소용 고압 다단펌프의 레이디얼 디퓨저 형상에 따른 펌프의 성능(양정, 효율)변화를 수치 해석적으로 분석하였다. 레이디얼 디퓨저 설계 변수는 크게 디퓨저 베인수, 디퓨저 외경비($D_4/D_3$), 리턴채널 출구각도(${\alpha}_6$), 압력회복계수($C_p$) 등으로 선정하였다. 수치해석 결과 디퓨저 외경비가 큰 경우 양정 및 효율이 가장 크게 예측되었으며, 리턴채널의 출구각도(${\alpha}_6$)가 60도인 경우 디퓨저 출구에서의 Pre-Swirl로 인해 출구각도가 90도인 것에 비해 양정이 저하되는 것을 알 수 있다.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.159-164
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• 2001

An extensive range of pumping facilities are employed in the regional water supply system in metropolitan areas, and optimization and the systematic combination of the pump facilities have direct bearing on the stability and economy of the water supply system concerned. These systems must be able to guarantee stability, efficiency and offer high reliability. Preparation of metropolitan area regional water supply system construction project must include a basic plan which takes into account the suitability of pumping facilities to be used, the environment in which facilities will be installed, man-power requirements and basic operational and management policies. This paper contains over-all analysis of the management of metropolitan area regional water supply systems and highlights the cause of Inefficiency and energy waste and puts forward a remedial plan of action. In addition, pump/motor specification programs were developed using Visual Basic to assist selection of the same.

• Journal of Advanced Marine Engineering and Technology
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• 제39권4호
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• pp.456-462
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• 2015

본 연구는 토네이도와 축류펌프의 원리를 적용하여 마중물 없이 슬러리를 송출할 수 있는 새로운 펌프기술 개발을 목적으로 한다. 개발한 로터형 슬러리 펌프는 전동모터, 구동축 및 커플링, 로터, 임펠러 그리고 흡입 및 송출관으로 구성된다. 청수를 이용한 성능실험에서는 로터의 설계조건에 따른 송출량, 소비 전력량 그리고 흡입관 부압특성에 대해 모터의 회전수를 변수로 검증하였으며, 시멘트를 이용하여 제조한 슬러리의 고형물 농도에 따른 송출량 특성에 대한 검증연구를 수행하였다. 로터의 직경과 높이가 커지면 송출량과 소비되는 전력량은 증가하지만 흡입관 부압은 감소하였으며, 송출량과 부압에 미치는 로터 두께의 영향은 거의 나타나지 않았다. 개발지표로 제시하였던 18 % 이상의 고형물 농도에서도 슬러리의 송출이 가능함을 확인하였다.

• International Journal of Fluid Machinery and Systems
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• 제3권2호
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• pp.122-128
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• 2010

The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance; however, cavitation surge oscillation with low frequency occurs with blade cavity growing to each throat section of blade passage simultaneously. Then, one conceptual method of installing suction axi-asymmetrical plate has been proposed so as to keep every throat passage away from being unstable at once, and the effect on suppression of the oscillation were investigated. In the present study, cavitation behaviors in the inducer is observed with distributing multi-cameras circumferentially, recording simultaneously and reconstructing multi-photos on one plane field as moving a linear cascade. Observed results are utilized for discussion with other measuring results as casing wall pressure distribution. Then the suppression mechanism of oscillation by installing axi-asymmetrical inlet plate will be clarified in more details.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.92-92
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• 1996

Recently, with the rapid development in the oceanic systems such as the oceanic structures and vessel, there occurs much interest in the impingement erosion-corrosion. In this paper, Cu-metal was tested by using of erosion apparatus with water-jet type and was investigated under the behaviour of impingement erosion-corrosion according to various environmental conditions, and the properties of Cu-metal were evaluated through the measurement by weight loss, weight loss rate, protective efficiency. The results were compared with those obtained using Cu-metal applied to cathodic protection and Cu-alloys added to Zn or Al-metal. As a basis of those results, the best protective efficiencies could be taken as using cathodic protection method and Cu-alloy with Al & Zn material addings, and will be suggested as the fundamental data of the anti-impingement erosion-corrosion on Cu-metal of impeller material for oceanic centrifugal pump.

• Journal of Advanced Marine Engineering and Technology
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• 제20권2호
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• pp.24-31
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• 1996

Recently, with the rapid development in the oceanic systems such as the oceanic structures and vessel, there occurs much interest in the impingement erosion-corrosion. In this paper, Cu-metal was tested by using of erosion apparatus with water-jet type and was investigated under the behaviour of impingement erosion-corrosion according to various environmental conditions, and the properties of Cu-metal were evaluated through the measurement by weight loss, weight loss rate, protective efficiency. The results were compared with those obtained using Cu-metal applied to cathodic protection and Cu-alloys added to Zn or Al-metal. As a basis of those results, the best protective efficiencies could be taken as using cathodic protection method and Cu-alloy with Al & Zn material addings, and will be suggested as the fundamental data of the anti-impingement erosion-corrosion on Cu-metal of impeller material for oceanic centrifugal pump.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2183-2195
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• 2020

A mathematical model for the flowrate and rotation speed of RCP during idling was established. The numerical calculation method and dimensionless method were used to analyze the flow, head, torque and pressure and speed changes under idle conditions. Regularity, using the Q criterion vortex identification judgment method combined with surface flow spectrum morphology analysis to diagnose the vortex dynamic characteristics on RCP blade. On impeller blade, there is two oscillations in the pressure ratio on pressure surface in blade outlet region. The velocity on the suction surface is two times more oscillating than the inlet of blade, and there is an intersection with the velocity ratio curve on pressure surface. On blade of guide vane, the pressure ratio increases along the inlet to outlet direction, and the speed ratio decreases with the increase of idle time. There is a vortex that rotates counterclockwise on the suction surface, and the streamline on the suction surface of blade is subjected to the entrainment and blocking action of the vortex creates a large reverse flow in the main flow region. There are two vortices at the outlet of guide vane suction side and the vortices are in opposite directions.

• International Journal of Fluid Machinery and Systems
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• 제3권1호
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• pp.50-57
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• 2010

The attachment of inducer in front of main impeller is a powerful method to improve cavitation performance. Cavitation surge oscillation, however, often occurs at partial flow rate and extremely low suction pressure. As the cavitation surge oscillation with low frequency of about 10 Hz occurs in a close relation between the inlet backflow cavitation and the growth of blade cavity into the throat section of blade passage, one method of installing an axi-asymmetrical plate upstream of inducer has been proposed to suppress the oscillation. The inlet flow distortion due to the axi-asymmetrical plate makes different elongations of cavities on all blades, which prevent the flow from becoming simultaneously unstable at all throat sections. In the present study, changes of the suppression effects with the axial distance between the inducer inlet and the plate and the changes with the blockage ratios of plate area to the cross-sectional area of inducer inlet are investigated for helical inducers with tip blade angles of $8^{\circ}$ and $14^{\circ}$. Then a conceivable application will be proposed to suppress the cavitation surge oscillation by installing axi-asymmetrical inlet plate.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2005년도 춘계 학술대회
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• pp.21-29
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• 2005

30 MW의 연구용 원자로인 하나로는 1995년 2월 초임계에 도달한 이후, 정상적으로 가동하고 있다. 가동 후 약 10년이 경과하여 1차 냉각펌프를 분해 점검하기 위해 펌프에 대한 화학제염이 2004년에 수행되었다. 제염을 수행하기 이전에 4개의 point를 설정하여 방사선량율 및 표면오염도를 측정하였고, 최종제염이 수행된 이후 같은 point에 대하여 방사선량율 및 표면오염도를 재측정 하였다. 펌프 외부는 노출되어 있어 쉽게 제염할 수 있으나 케이싱 내부에는 2중 볼류트가 있어 접근이 용이하지 않았다. 이를 제염하기 위하여 제염장치를 개발하였다. 이 장치는 일정 농도의 제염제 (DX-300)를 케이싱 내부에 담아 밀폐시킨 후 펌프의 임펠러를 저속으로 회전함으로서 제염제가 순환된다. 제염제의 유화작용에 의해 표면의 입자성 방사선 물질이 이완되고, 화학 작용에 의해 부식력과 용해성으로 표면 오염이 제거된다. 이 장치를 이용하여 하나로 1차 냉각펌프의 케이싱 내부를 제염하였다. 그 결과 1차 냉각펌프의 케이싱 내부는 반출허용표면오염도 이하로 낮출 수 있어 성공적으로 제염할 수 있었다.