Piping structural design for the ITER thermal shield manifold

Noh, Chang Hyun,Chung, Wooho,Nam, Kwanwoo,Kang, Kyoung-O.,Bae, Jing Do,Cha, Jong Kook,Kim, Kyoung-Kyu,Hamlyn-Harris, Craig,Hicks III, Robby,Her III, Namil,Jun III, Chang-Hoon Elsevier 2015 Fusion engineering and design Vol.98 No.-

<P><B>Abstract</B></P> <P>The thermal shield (TS) provides the thermal barrier in the ITER tokamak to minimize heat load transferred by thermal radiation from the hot components to the superconducting magnets operating at 4.2K. The TS is actively cooled by 80K pressurized helium gas which flows from the cold valve box to the cooling tubes on the TS panels via manifold piping. This paper describes the manifold piping design and analysis for the ITER thermal shield. First, maximum allowable span for the manifold support is calculated based on the simple beam theory. In order to accommodate the thermal contraction in the manifold feeder, a contraction loop is designed and applied. Sequential Quadratic Programming (SQP) method is used to determine the optimized dimensions of the contraction loop to ensure adequate flexibility of manifold pipe. Global structural behavior of the manifold is investigated when the thermal movement of the redundant (un-cooled) pipe is large.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We finalized piping design of ITER thermal shield manifold for procurement. </LI> <LI> Support span is determined by stress and deflection limitation. </LI> <LI> SQP, which is design optimization method, is used for the pipe design. </LI> <LI> Benchmark analysis is performed to verify the analysis software. </LI> <LI> Pipe design is verified by structural analyses. </LI> </UL> </P>

Issues Related to the Modeling of Solid Oxide Fuel Cell Stacks

Yang Shi,Ramakrishna P.A.,Sohn Chang-Hyun The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.3

This work involves a method for modeling the flow distribution in the stack of a solid oxide fuel cell. Towards this end, a three dimensional modeling of the flow through a Solid Oxide Fuel Cell (SOFC) stack was carried out using the CFD analysis. This paper examines the efficacy of using cold flow analysis to describe the flow through a SOFC stack. It brings out the relative importance of temperature effect and the mass transfer effect on the SOFC manifold design. Another feature of this study is to utilize statistical tools to ascertain the extent of uniform flow through a stack. The results showed that the cold flow analysis of flow through SOFC might not lead to correct manifold designs. The results of the numerical calculations also indicated that the mass transfer across membrane was essential to correctly describe the cathode flow, while only temperature effects were sufficient to describe the anode flow in a SOFC.

원형 제한 3체 문제의 불변위상공간을 이용한 행성간 궤적설계 기초 연구

정옥철(Okchul Jung),안상일(Sangil Ahn),정대원(Daewon Chung),김은규(Eunkyou Kim),방효충(Hyochoong Bang) 한국항공우주학회 2015 韓國航空宇宙學會誌 Vol.43 No.8

본 논문에서는 원형 제한 3체 문제의 불변위상공간을 이용하여 지구-달 또는 행성간의 궤적을 설계하고 해석하는 기법을 소개한다. 2체 문제를 조합하는 고전적인 방식 대신에 원형 제한 3체 문제에 대한 운동방정식, 궤적의 동적 특성, 평형점 주변의 리아프누프 궤도와 불변위상공간의 특성을 기술한다. 원형 제한 3체 문제의 불변위상공간을 이용했을때, 지구-달 시스템의 궤적설계 방식과 태양-목성 시스템의 경계면에서의 초기조건에 따른 궤적 특성을 수치 시뮬레이션을 통해 확인한다. 본 논문에서 제안한 원형 제한 3체 문제의 불변위상공간을 이용한 궤적설계 기법은 저추력 또는 저에너지를 이용한 달탐사 또는 행성탐사 임무 등에 활용 가능할 것이다. This paper represents a trajectory design and analysis technique which uses invariant manifolds of the circular restricted three body problem. Instead of the classical patched conic method based on 2-body problem, the equation of motion and dynamical behavior of spacecraft in the circular restricted 3-body problem are introduced, and the characteristics of Lyapunov orbits near libration points and their invariant manifolds are covered in this paper. The trajectories from/to Lyapunov orbits are numerically generated with invariant manifolds in the Earth-moon system. The trajectories in the Sun-Jupiter system are also analyzed with various initial conditions in the boundary surface. These methods can be effectively applied to interplanetary trajectory designs.

심해저 원유 생산용 매니폴드 프레임 구조 기본 설계

박세용(Se-Yung Park),정준모(Joonmo Choung) 한국해양공학회 2015 韓國海洋工學會誌 Vol.29 No.3

Amanifold is one of the essential subsea oil and gas production components to simplify the subsea production layout. It collects the production fluid from a couple of wellheads, transfers it to onshore or offshore storage platforms, and even accommodates water and gas injection flowlines. This paper presents the basic design procedure for a manifold frame structure with novel structural verification using in-house unity check codes. Loads and load cases for the design of an SIL 3 class-manifold are established from a survey of relevant industrial codes. The basic design of the manifold frame is developed based on simple load considerations such as the self weights of the manifold frame and pipeline system. In-house software with Eurocode 3 embedded, called INHA-SOLVER, makes it possible to carry out code checks on the yield and buckling unities. This paper finally proves that the new design of the manifold frame structure is effective to resist a permanent and environment load, and the in-house code is also adaptively combined with the commercial finite element code Nastran.

3차원 CFD 시뮬레이션을 활용한 고분자전해질연료전지 스택의 매니폴드 크기 최적화

정지훈,한인수,신현길 한국수소및신에너지학회 2013 한국수소 및 신에너지학회논문집 Vol.24 No.5

Polymer electrolyte membrane (PEM) fuel cell stacks are constructed by stacking several to hundreds of unit cells depending on their power outputs required. Fuel and oxidant are distributed to each cell of a stack through so-called manifolds during its operation. In designing a stack, if the manifold sizes are too small, the fuel and oxidant would be maldistributed among the cells. On the contrary, the volume of the stack would be too large if the manifolds are oversized. In this study, we present a three-dimensional computational fluid dynamics (CFD) model with a geometrically simplified flow-field to optimize the size of the manifolds of a stack. The flow-field of the stack was simplified as a straight channel filled with porous media to reduce the number of computational meshes required for CFD simulations. Using the CFD model, we determined the size of the oxidant manifold of a 30 kW-class PEM fuel cell stack that comprises 99 cells. The stack with the optimal manifold size showed a quite uniform distribution of the cell voltages across the entire cells.

Sliding Manifold Design for Higher-order Sliding Mode Control of Linear Systems

Boban Veselic,Cedomir Milosavljevic,Branislava Drazenovic,Senad Huseinbegovic 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.8

The paper considers sliding manifold design for higher-order sliding mode (HOSM) in linear systems. In this case, the sliding manifold must meet two requirements: to achieve the desired dynamics in HOSM and to provide the appropriate relative degree of the sliding variable depending on the SM order. It is shown that in the case of single-input systems, a unique sliding manifold can be determined that satisfies these two requirements, whereas in multi-input case, such a manifold exists only in systems satisfying specific structural constraints. Theoreticallyobtained results are validated through numerical examples and illustrated by digital simulations.

고분자 전해질 연료전지 매니폴드의 열유동 특성에 관한 수치적 연구

정혜미(Jung, Hye-Mi),엄석기(Um, Sukkee),손영준(Sohn, Young-Jun),박정선(Park, Jungsun),이원용(Lee, Won-Yong),김창수(Kim, Chang-Soo) 한국신재생에너지학회 2005 신재생에너지 Vol.1 No.2

The effects of internal manifold designs on the reactants feed-stream in Polymer Electrolyte Fuel Cells [PEFCs] is studied to figure out flow and thermal distribution patterns over an entire fuel cell stack. Reactants flows are modeled either laminar of turbulent depending on regions and the open channels in the bipolar plates are simulated by porous media where permeability should be pre-deter-mined for computational analysis. In this work, numerical models for reactants feed-stream In the PEFC manifolds are classified Into two major flow patterns: Z-shape and U-shape. Several types of manifold geometries are analyzed to find the optimal manifold configurations. The effect of heat generation in PEFC on the flow distribution is also Investigated applying a simplified heat transfer model in the stack level (i.e. multi-cell electrochemical power-generation unit). This modeling technique Is well suited for many large scale problems and this scheme can be used not only to account for the manifold flow pattern but also to obtain Information on the optimal design and operation of PEFC systems.

고분자 전해질 연료전지의 매니폴드 설계 및 해석

정혜미(JUNG, Hye-Mi),엄석기(UM, Sukkee),박정선(PARK, Jungsun),이원용(LEE, Won-Yong),김창수(KIM, Chang-Soo) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

The effects of internal manifold designs the reactant feed-stream in Polymer Electrolyte Fuel Cells (PEFCs) is studied to figure out mass flow-distribution patterns over an entire fuel cell stack domain. Reactants flows are modeled either laminar or turbulent depending on regions and the open channels in the bipolar plates are simulated by porous media where permeability should be pre-determined for computational analysis. In this work, numerical models for reactant feed-stream in the PEFC manifolds are classified into two major flow patterns: Z-shape and U-shape. Several types of manifold geometries are analyzed to find the optimal manifold configurations. The effect of heat generation in PEFC on the flow distribution is also investigated applying a simplified heat transfer model in the stack level (i.e. multi-cell electrochemical power-generation unit). This modeling technique is well suited for many large scale problems and this scheme can be used not only to account for the manifold flow pattern but also to obtain information on the optimal design and operation of a PEMC system.

DFSS 기법을 이용한 흡기 매니폴드의 최적 설계

홍순성(Soonseong Hong),이진호(Jinho Lee),민선기(Sunki Min),김숭기(Soongkee Kim) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

DFSS (Design for Six Sigma) is a very useful method to optimize product design in various fields of the industry. This paper presents the implementation of the DFSS method to optimize an engine intake manifold with PDA system. The focus of optimization is to maximize the swirl strength and mass flow rate in the cylinder chamber. There are so many factors that affect the swirl strength and mass flow rate in intake manifold system, but only six main control factors such as plenum shape, primary and secondary length, port diameter, primary pipe section shape, etc. are adopted. The L18 orthogonal table is used for calculating CFD simulation to evaluate the swirl number and mass flow rate in the cylinder chamber.

Additive Manufacturing of a Release Agent Injection Manifold for Hot Forging

이학성(Hak-Sung Lee),정민교(Min-Kyo Jung),김은아(Eun-ah Kim),원순호(Soonho Won),천도욱(Do Wock Chun),하태호(Taeho Ha) Korean Society for Precision Engineering 2021 한국정밀공학회지 Vol.38 No.9

In this study, design for additive manufacturing (DfAM) of release agent injection manifold for hot forging has been performed to achieve weight reduction and flow path optimization. The weight reduction of 53.5% was achieved, thereby enabling the application of stainless steel 316L, which has high strength and corrosion resistance. Lightweight manifolds using Al-Mg-10Si and SUS316L materials were fabricated by PBF-type metal 3D printer. The feasibility test showed that mold life was improved by 14% by solving residual release agent problem. In addition, the flow path optimization results suggested that the flow standard deviation of each outlet dropped sharply from 264 to 75 ㎤/s. This approach demonstrated that DfAM for release agent manifold could be applied to increase mold life and improve product quality and productivity for hot forging.