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볼루트의 형상 변화가 원심펌프 성능에 미치는 영향에 대한 수치해석
이정현(J.H. Lee),허남건(N. Hur),윤인식(I.S. Yoon) 한국전산유체공학회 2015 한국전산유체공학회지 Vol.20 No.3
Centrifugal pumps consume considerable amounts of energy in various industrial applications. Therefore, improving the efficiency of pumps machine is a crucial challenge in industrial world. This paper presents numerical investigation of flow characteristics in volutes of centrifugal pumps in order to compare the energy consumption. A wide range of volumetric flow rate has been investigated for each case. The standard k-ε is adopted as the turbulence model. The impeller rotation is simulated employing the Multi Reference Frames(MRF) method. First, two different conventional design methods, i.e., the constant angular momentum(CAM) and the constant mean velocity (CMV) are studied and compared to a baseline volute model. The CAM volute profile is a logarithmic spiral. The CMV volute profile shape is an Archimedes spiral curve. The modified volute models show lower head value than baseline volute model, but in case of efficiency graph, CAM curve has higher values than others. Finally for this part, CAM curve is selected to be used in the simulation of different cross-section shape. Two different types of cross-section are generated. One is a simple rectangular shape, and the other one is fan shape. In terms of different cross-section shape, simple rectangular geometry generated higher head and efficiency. Overall, simulation results showed that the volute designed using constant angular momentum(CAM) method has higher characteristic performances than one by CMV volute.
윤인식(I.S Yoon),김영범(Y.B Kim),장훈(H Jang),황지혁(J.H Hwang),강영미(Y.M Kang) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
AOV is fluid capacity and fluid pressure control in nuclear power plant with heating power plant. The control valve in order channel to control a high differential pressure developed in the form which is complicated and precise control form. From the research which sees in order description below analyzed the performance comparison which follows in trim forms of the control valve with CFD. The Result, multi-stage trim are a fluid kinetic energy small will prevent damages of AOV.
장훈(H Jang),윤인식(I.S. Yoon),김영범(Y.B. Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
At the inlet and outlet differential pressure and The fluid velocity over 32㎧ 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.
김영범(Y.B Kim),장훈(H Jang),윤인식(I.S. Yoon),강영미(Y.M. Kang) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
Under localization developing for the control valve of the safety grade Q Class 1 which is established in the atomic power plant followed ASME Code and important parts (Body, Yoke, Bonner, Actuator) design and produced. In order to verify this analyzed the earthquake stress of AOV. AOV the above of 33㎐ occurred from first mode, the earthquake stress occurred from inside the yield strength of the material.
김영범(Y. B. Kim),권갑주(K. J. Kwon),윤인식(I. S. Yoon),최종귀(J. K. Choi),황지혁(J. H. Hwang),손기철(K. Ch. Son),김성영(S. Y. Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
Domestic Enforcement Regulation of the Atomic Energy Act requires the Equipment Qualification (EQ) of safety-related equipment in nuclear power plants to be included at Periodic Safety Review (PSR). The purpose of this study is to verify the integrity of AOV (Air Operated Valve) actuator by equipment qualification, which will be followed by the localization of the AOV and its actuator. The AOV actuator, whose model number is SDD-VA-1, was developed based on the requirements of the relevant ASME and ASNI Codes. The procedure for the equipment qualification was established based on the EQ Rule (10CFR50.49), Reg. Guide 1.89, IEEE 323(1983) and IEEE 382(1972). Detailed test procedure was based on that of Korea Institute of Machinery and Materials (KIMM) and the EQTR of a referenced valve was used.
장훈(H Jang),김영범(Y.B Kim),권갑주(K.J Kwon),윤인식(I.S Yoon),윤재원(J.W Yoon) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
Unsteady state fluid flow is caused by the very high-potential energy of fluid like cavitation, flashing and hammering in the Nuclear Power Plants. The main components of a valve are damaged by them. The control valve under high pressure drop that limites velocity of fluid on 30m/s is used to solve the problems. In this case, the reduction of generating power is caused by fail to the control of fluid. In this paper, the control valve trim under high pressure drop which is called Helical Trim was developed to control fluid flow. The pressure, velocity, and movement Pattern of fluid in control valve were analyzed by using numerical analysis program which is called ANSYS CFX. It was performed to compare calculated valve flow coefficient using dynamic characteristics test facility and design data and relevance of high-precision fluid control was analyzed.
CAVITATION ANALYSIS IN A CENTRIFUGAL PUMP USING VOF METHOD
W.J. Lee(이원주),J.H. Lee(이정현),N. Hur(허남건),I.S. Yoon(윤인식) 한국전산유체공학회 2015 한국전산유체공학회지 Vol.20 No.4
Centrifugal pumps consume considerable amount of energy in various industrial applications. Therefore, improvement of the efficiency of these machines has become a major challenge. Cavitation is a phenomenon which decreases the pump efficiency and even causes structural demage. Hence, the goal of this paper is to investigate the cavitation problem in the single-stage and double-stage centrifugal pumps. The Volume of Fraction (VOF) method has been used for the numerical simulations together with Rayliegh-Plesset model for the gas-liquid two-phase flow inside the pump. In order to capture the turbulent phenomena, the standard k-ε turbulence model has been adopted, and the simulations have been done as unsteady cases. In addition, the motion of the rotating parts has been simulated using Multi Reference Frame(MRF) method. The results are presented and compared in terms of hydraulic head and NPSH for both the single-stage and double-stage pumps. The H-Q curves show the effects of cavitation on decreasing the pumps performances.