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보일러 급수펌프용 고차압 제어밸브 1500lb 국산화 개발에 관한 연구
이권일,장훈,이치우 한국기계가공학회 2022 한국기계가공학회지 Vol.21 No.8
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
고차압 글로브 밸브 트림의 anti-cavitation에 관한 수치적 연구
김대권(Dae Kwon Kim),손채훈(Chae Hoon Sohn) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11
A globe valve is one of devices which control mass flow rate. In nuclear powerplants, it is usually used for high pressure drop over 100 bar. To attain the high pressure drop, trim in a valve should be designed elaborately to avoid the occurrence of local cavitation in a valve. Trim for high-pressure drop is classified into two types of pressure control and velocity control. This work is focused on design of trim with velocity-control type. Suitable geometry or shape of trim is pursued numerically, which should satisfy two conditions of high-pressure drop and suppression of local cavitation phenomenon. For operating conditions of actual powerplants, flow characteristics and cavitation area are examined numerically. Several trim geometries are proposed as candidates for trim with velocity-control type.
고차압 밸브의 속도제어형 트림에서 케이테이션 억제에 관한 수치적 연구
김대권(Dae Kwon Kim),손채훈(Chae Hoon Sohn) 대한기계학회 2013 大韓機械學會論文集B Vol.37 No.9
본 수치적 연구에서는 국내의 발전소에서 사용되는 일반적인 고차압 트림의 형상 중 대표적으로 사용되는 형상의 트림을 기본형 트림으로 정하여, 이를 설계한 후 캐비테이션과 유량의 관점에서 유동특성을 살펴보았다. 실제로 운전되는 발전소계통의 운전조건을 참고하여 고차압 조건으로서 입·출구 차압을 18.7 MPa로, 온도를 160℃ 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. Flow characteristics of velocity-control trim in a valve is investigated numerically with high pressure drop. A basic trim widely used for a valve in domestic powerplants is selected and designed for a baseline of velocity-control trim. The numerical analysis is focused on flow rate and cavitation with the basic trim. For a condition of high-pressure drop, pressure drop between inlet and outlet and fluid temperature are selected to be 18.1 MPa and 160℃, respectively, which are typical ones considering operating conditions adopted in powerplants. With this baseline model and condition, design changes are made for improvement of flow rate and cavitation phenomenon. For re-design, trim is divided into three zones in radial direction and design parameters of flow area, stage, and flow direction are considered in each zone. With these combined parameters applied to each zone, 4 models with design changes are proposed and their flow rates and cavitation areas are investigated. From comparison with those in the baseline model of a basic trim, proposed models show better performance in both flow rate and cavitation.
Anti-Cavitation Trim을 갖는 고차압 제어밸브의 유동특성에 관한 수치해석
안영준(Y. J. Ahn),김병진(B. J. Kim),신병록(B. R. Shin) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-
Numerical analysis of three dimensional incompressible turbulent flows in LNG marine high pressure drop control valves was carried out by using the commercial CFD-ACE code. 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.
강효림(Hyo Lim Kang),황해성(Hae Seong Hwang),한승호(Seung Ho Han) 대한기계학회 2020 大韓機械學會論文集A Vol.44 No.5
발전 설비에서 사용되는 고차압 제어밸브는 보일러에서 유입되는 고압의 유체를 안전한 수준의 압력으로 저하시켜 터빈에 유입시키는 역할을 한다. 그중 미로형 유로(labyrinth path)가 적용된 고차압제어밸브는 고속의 유체가 구불구불한 유로를 통과하며 발생하는 저항으로 압력 강하를 만든다. 본 연구에서는 미로형 유로를 갖는 케이지를 7단으로 적층한 1-1/2” 고차압 제어밸브에 대하여 유로의 꺾임부분에 확산각(divergence angle)을 부여하여 유로를 개선하였으며, 개선 결과 기존의 유로 대비 차압 성능이 평균 12.7% 증가하였다. 또한 확산각으로 인해 미로형 유로의 후방에 나타나는 공동 현상을 다상유동 해석으로 얻어진 증기 체적률로 정량화하여 공동에 의해 파손이 발생하지 않는 확산각의 크기를 선정하였으며, 확산각 α가 30° 미만인 경우 차압 성능 향상은 물론 공동에 의한 문제도 피할 수 있음을 해석적으로 검증하였다. High-pressure-drop control valves used in power plants play an important role of depressurizing highly pressurized fluids in a boiler and bringing these fluids into the turbine. Labyrinth control valves have been used widely owing to their pressure drop performance due to the resistance created by high-speed fluids passing through the labyrinth path. This paper proposes an improved configuration of the labyrinth path in a 1-1/2” control valve with 7-stage cages by considering the valve divergence angles. The pressure drop performance was estimated using computational fluid dynamics analysis, and the flow characteristics caused by the divergence angles were studied. As a result, the pressure drop performance increased by a factor of approximately 12.7. Moreover, a numerical analysis of the multi-phase flow was performed to quantify the vapor volume fraction of the cavitation effect which occurred at the outlet of the labyrinth path. Consequently, divergence angles of less than 30° were proposed to prevent mechanical failures of the labyrinth path due to cavitation.
정연호(Jeong Yeon-ho),김영범(Kim Young-bum),정호열(Jeong ho-youl),심영권(Shim young-kwon),최승욱(Choi seung-wook),문재휘(Moon Jae-Hui) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11
Steam soot-blower control valves for thermal power plants operate in a uniquely severe service and environment. They must not only frequently modulate flow over a wide range but must also maintain downstream pressure between very close limits at high differential. In addition, they also must function as block valves with tight shutoff every time they close to prevent soot-blower header pressure safety relief valve operation due to system overpressure. Satisfactory operation in these two separate functions is a problem often found in the power industry. Because of poor valve operating experience the soot-blower control valves were recently replaced with valves specifically designed for soot-blower service.