• 대한기계학회논문집B
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• 제37권9호
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• pp.863-871
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• 2013

본 수치적 연구에서는 국내의 발전소에서 사용되는 일반적인 고차압 트림의 형상 중 대표적으로 사용되는 형상의 트림을 기본형 트림으로 정하여, 이를 설계한 후 캐비테이션과 유량의 관점에서 유동 특성을 살펴보았다. 실제로 운전되는 발전소계통의 운전조건을 참고하여 고차압 조건으로서 입 출구 차압을 18.7 MPa로, 온도를 $160^{\circ}C$로 설정하였다. 트림의 주요 설계 인자로서 유로의 면적, 유로의 단(stage)과 유로의 방향을 채택하여, 유량과 케비테이션 발생 특성을 개선하기 위해 기본형 트림을 재설계하였다. 개선을 위해 트림을 반경방향으로 세 영역으로 나눈 후 각 영역에서 재설계 인자를 이용하여 형상을 변경하였다. 4가지의 재설계 모델을 제안하였으며, 각 모델 형상에 대한 수치해석을 수행하였다. 유량 및 캐비테이션 발생량의 관점에서 기본형 트림과 설계개선 트림들을 비교하여 재설계 모델의 성능이 개선되었음을 확인하였다.

• 한국기계가공학회지
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• 제20권8호
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• pp.107-114
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• 2021

Butterfly valves are used in various industries to control the flow rate, flow direction, pressure, and temperature. These are gaining popularity in the field of plant industry to enable high-differential pressure because of their low maintenance costs and ease of installation. This study presents a numerical analysis method to analyze changes in the flow characteristics of a high-differential pressure control butterfly valve based on the location and shape of the orifice. The numerical analysis was conducted using a commercial CFD program. The analysis results show a correlation between the orifice shape and cavitation phenomenon.

• 한국생산제조학회지
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• 제20권5호
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• pp.553-558
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• 2011

This study have goal with conceptual design for offshore structures of high pressure drop control valve for localization valve for development accomplished with flow analysis based on provision of ANSI B16.34, ANSI B16.10, ANSI B16.25. In order to localize the Offshore structures high pressure drop control valve. This study is numerical analysis for zambil offshore project of high pressure drop control valve. The solver which ANSYS workbench used for offshore structures analysis. The working fluids assumed the glycerin(C3H8O3). The structural analysis used ANSYS which is a commercial code. Stress analysis result of internal pressure in valve showed lower than yield strength. This is expect to need more detail design and verification for stem and disk structure. In this study a multi-disk of high pressure drop control valve is designed and manufactured. Then, the flow rate and high pressure dorp of fluids flowing in the high pressure drop control valve is CAE. So, this system can be easily substituted for the existing zambil offshore project system. Finally, safety estimation for trim design of high pressure drop control valve for offshore structures.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.581-584
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• 2008

At the inlet and outlet differential pressure and The fluid velocity over 32m/s are damaged (Plug, sheet ring, trim) About reduction trim parts of the control valve. AOV of the differential pressure 1,500psi become often the damage in the nuclear power plant. Damages of AOV studied CFD analysis and improvement program. Multi-stage trim designs which decrease a fluid kinetic energy are demanded and AOV parts are demanded case hardening and material change.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2010년도 학술발표회
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• pp.213-217
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• 2010

댐붕괴파 (dam-break flow)나 지진해일에 의해 발생하는 undular bore와 충격파 (shock) 현상을 동수압 및 분산효과를 고려하여 수치모의를 수행하였다. 완전비선형 Boussinesq-type equations 모형을 이용하여, 동수압 및 분산 효과를 고려하였다. 방정식은 4차 정확도의 유한체적법을 이용하여 해석하였고, 시간적으로도 4차정확도의 기법을 이용하여 고차미분항에 대한 수치분산을 억제하였다. 다양한 경우의 1차원과 2차원 공간에서의 수치모의를 수행하고 검증을 수행하였다. 그 결과, 완전비선형 Boussinesq-type equations 모형은 천수방정식 (shallow water equations) 기반의 모형에서 재현이 불가능한 undular bore 등을 재현 하는 등, 전반적으로 천수방정식 기반의 모형 보다 물리적으로도 타당하고 정량적으로도 실험결과와 잘 일치하는 경향을 보였다. 즉, 댐붕괴파나 지진해일 등에 의한 범람 모의에 있어 동수압과 분산 효과의 중요성이 공학적으로도 매우 중요한 고려사항 임이 나타났다.

• 한국기계가공학회지
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• 제21권8호
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• pp.19-24
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• 2022

We developed a prototype from the design of a trim, which is the most important in the localization development of a 1500 Ib high-differential pressure-control valve used for boiler feedwater, and measured the flow coefficient, the most basic design data for valves. The following conclusions were drawn. The comparison of the design values of the flow coefficients for the existing X-trim and the multicore trim designed for localization development showed that they were almost identical, and the X-trim value was slightly lower. The comparison of the X-trim and multicore trim based on the valve flow coefficient test showed that they were generally similar, indicating no problem with the design. In the future, we plan to compare and analyze the flow paths for the X-trim and multicore trim via flow analysis.

• 한국유체기계학회 논문집
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• 제8권1호
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• pp.16-22
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• 2005

This paper presents the method of ROL(Rate Of Loading) improvement for the Motor Operated Gate Valve operated in high differential pressure condition. ROL is one of the most important evaluation parameters for the valve ability. It is close to correlation in stem factor (SF) and appears different value by the differential pressure of fluid. ROL and SF are analyzed by the static test and dynamic test. The obtained result show that the modification of stem factor is very important factor for the ROL improvement. In order to obtain the same value of SF between static and dynamic test, stem and stem nut should be combined appropriately by the repetition test.

• 한국유체기계학회 논문집
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• 제4권3호
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• pp.14-20
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• 2001

Numerical analysis of the three dimensional turbulent flow field in a complex valve trim is carried out to confirm the possibility whether this simulation tool can be used as a design tool or not. The simulation of the incompressible flow in a glove valve is performed by using the commercial code. CFD-ACEA utilizes the finite volume approach as a discretization scheme, and the pressure-velocity coupling is made from SIMPLEC algorithm in it. Four flow cases of the control valve are investigated, and the valve flow coefficient for each case is compared with the experimental data. Simulation results show a good agreement with the experiments, and it is observed that the cavitation model improves the simulation results.

• 한국유체기계학회 논문집
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• 제10권4호
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• pp.61-70
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• 2007

Numerical analysis of three dimensional incompressible turbulent flows in LNG marine high pressure drop control valves was carried out by using the CFD-ACE from ESI-Group. In this study, flow characteristics of control valves with complex flow fields including cavitation effect were investigated. Simulation was performed on five models of control valve that had different orifice diameters of anti-trim and the size of valve. Comparing newly designed control valves for controling the occurrence of cavitation with the conventional valve, new valves showed a improved flow pattern with almost no cavitation.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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• pp.562-567
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• 2003

This paper presents the method of Rate of Loading(ROL) improvement for the Motor Operated Gate Valve operating in high differential pressure condition. The character of ROL and Stem Factor is analyzed. Static test and dynamic test were performed and acquired the diagnosis signal for the valve closing stroke. The result of this study is the modification of stem factor is very important factor for the ROL improvement. In order to obtain the same value of dynamic test thread friction coefficient stem and stem nut should be combined appropriately.