Lessons learned from the design and fabrication of the baffles and heat shields of Wendelstein 7-X

Fusion Engineering and Design

Dekorsy

et al. 2014

Self Cite

The In-Vessel Components (IVC) of the stellarator Wendelstein 7-X consist of the divertor components and the first wall (FW) with their internal water cooling supply and a set of diagnostics. Due to the significant amount of different components, including many variants, a tool called Production Managing System (PMS) has been developed to organize the fabrication and the associated quality assurance. The PMS works by building a database containing the basic parts and assembly data, manufacturing and quality control plans, and available machine capacity. The creation of this database is based mainly on the parts lists, the manufacturing drawings, and details of the working flow organization. As a consequence of the learning process and technical adjustments during the design and manufacturing phase, the database needed to be permanently updated. Therefore an interface tool to optimize the data preparation has been developed. PMS has been demonstrated to be an efficient tool to support the IVC production activities providing reliable planning estimates, easily adaptable to problems encountered during the fabrication and provided a basis for the integration of quality assurance requirements .

Section: Per Part Per Typementioning

confidence: 99%

“…Due to the easy data installation, flexibility and simple maintenance, this tool is particularly suitable for a small manufacturing enterprise. These advantages of PMS were used frequently as technical adjustments during the design and manufacturing phase occurred relatively often [7,8,9,10].…”

Section: Introductionmentioning

confidence: 99%

Production management and quality assurance for the fabrication of the In-Vessel Components of the stellarator Wendelstein 7-X

Fusion Engineering and Design

Dekorsy

et al. 2014

Self Cite

“…1) consist of the actively water-cooled first wall protection, the divertor systems, the cryo-pumps and the control coils, as well as diagnostics and instrumentation, adding up to a total of ~700 000 components with a total weight (without coolant) of about 33 800 kg. The present design foresees 55 diagnostics and ~4 km of pipes assigned to 304 cooling circuits with 106 variants for 890 divertor targets, 300 stainless steel panels, 170 baffle modules and 162 heat shields to be installed [5], [6]. Each cooling circuit and wiring bundle enters the plasma vessel via feed-throughs inside of dedicated ports -the Plug-Ins, which ensure that the vacuum boundary between the plasma vessel and the torus hall atmosphere is maintained.…”

Section: In-vessel Componentsmentioning

confidence: 99%

Configuration Space Control Using the Example of In-Vessel Components for Wendelstein 7-X

Tretter

IEEE Trans. Plasma Sci.

Mendelevitch

et al. 2014

-Concurrent engineering with the design of increasingly complex components requires addition tools to avoid space conflicts. Configuration Space Control is a key technology necessary to achieve the required design efficiency and product development of a complex experiment. Easily accessible solutions available within CAD Frameworks, Product Data Management, and Configuration Management Systems currently only solve part of this task. Therefore, it has been vital to develop and control a set of procedures which handle the concurrent engineering issues and manage the compatibility of the various components being designed, manufactured and assembled. In addition a defined set of procedures are required to control the changes, additions and non-conformities to the design of components which occur in a developing experiment. To cope with these tasks, sophisticated tools and procedures have been adapted, developed and implemented. This paper covers the Configuration Space Control process for In-Vessel Components of Wendelstein 7-X, and demonstrates its application in the control of the as-assembled components.

“…For this phase of machine operation, plasma simulations show that the evolution of bootstrap current in certain plasma scenarios produce excessive heat fluxes on the divertor edge elements. (For details on the high heat-flux divertor, its design and cooling, see [1][2][3]). Simulations have shown the heat fluxes on these edge elements to be significantly above the design limit of 5 MW/m 2 .…”

Section: Introductionmentioning

confidence: 99%

Modeling and Analysis of the W7-X High Heat-Flux Divertor Scraper Element

Lumsdaine

IEEE Trans. Plasma Sci.

Clark

et al. 2014

Abstract-The Wendelstein 7-X stellarator experiment is scheduled for the completion of device commissioning and the start of first plasma in 2015. At the completion of the first two operational phases, the inertially cooled test divertor unit will be replaced with an actively cooled high heat-flux divertor which will enable the device to increase its pulse length to steady-state plasma performance.Plasma simulations show that the evolution of bootstrap current in certain plasma scenarios produce excessive heat fluxes on the edge of the divertor targets. It is proposed to place an additional "scraper element" in the ten divertor locations to intercept some of the plasma flux and reduce the heat load on these divertor edge elements. Each scraper element may experience a 500 kW steady-state power load, with localized heat fluxes as high as 20 MW/m 2 . Computational analysis has been performed in order to examine the thermal integrity of the scraper element.The peak temperature in the CFC, the total pressure drop in the cooling water, and the increase in water temperature must all be examined to stay within specific design limits. Computational fluid dynamics (CFD) modeling is performed to examine the flow paths through the multiple monoblock fingers as well as the thermal transfer through the monoblock swirl tube channels.