Validation of FE analysis results with selected W7-X in-vessel temperature measurements

IF 2 3区工程技术 Q1 NUCLEAR SCIENCE & TECHNOLOGY

Fusion Engineering and Design Pub Date : 2025-06-04 DOI:10.1016/j.fusengdes.2025.115171

M. Khokhlov , A. Lorenz , V. Smolik , V. Bykov , M. Hirsch , F. Reimold , T. Windisch , K. Rahbarnia , D. Zhang , Y. Gao , W7-X team

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引用次数: 0

Abstract

The Wendelstein 7-X (W7-X) experimental stellarator has been significantly technically enhanced in 2018–2021 and is now equipped with a full set of actively cooled plasma facing components (PFC). The upgraded PFCs allow experimental phases with higher energy and longer plasma pulses. During the last operational campaign (OP2.1) in 2022/2023, the maximum heating energy of 1.3 GJ was reached, and the 2 GJ milestone is expected in the upcoming 2024/2025 campaign. The final goal of W7-X is however 30 min with 10 MW ECRH (18 GJ) and shorter addition of NBI and ICRH heating.

This increased heating energy is transferred to the PFCs in the form of plasma loads and is largely absorbed by the cooling water in the PFCs. However, the in-vessel diagnostics behind the PFCs must also withstand the increased thermal loads. Therefore, several diagnostics with both active water cooling and with inertial cooling were analysed.

Moreover, additional thermocouples and resistance temperature sensors were installed prior to the last campaign to monitor temperatures in both the PFCs and other diagnostics during the plasma pulses. The focus of this activity was to validate the temperature readings from the various temperature sensors and the detailed FE analysis approaches and results. This work will allow reliable operating limits to be set for upcoming campaigns based on the thermal analyses results under expected loads with verified FE models.

First comparisons presented in the paper show good quantitative agreement between the in-vessel temperature measurements and the results of the FE analyses for selected diagnostic plug-ins. For some of the diagnostics maximum allowable temperatures in the temperature sensors have been calculated as input for operation monitoring for the next campaign. For the diagnostics behind the PFCs, there is a qualitative agreement between temperature measurements and calculations; the remaining deviations are mainly due to the complexity of correctly estimating the thermal permeability of the PFCs and not fully known assembly tolerances. Further validation of both the temperature measurements and the FE analysis results under expected higher loads is the important step towards verifying the safety of the operating limits of W7-X.

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用选定的W7-X容器内温度测量验证FE分析结果

Wendelstein 7-X （W7-X）实验仿星器在2018-2021年间得到了显著的技术改进，现在配备了全套主动冷却等离子体面向组件（PFC）。升级后的pfc允许实验阶段具有更高的能量和更长的等离子体脉冲。在2022/2023年的最后一次运行活动（OP2.1）中，达到了1.3 GJ的最大加热能量，预计在即将到来的2024/2025年活动中达到2 GJ的里程碑。然而，W7-X的最终目标是30分钟，10兆瓦ECRH (18 GJ)，以及更短的NBI和ICRH加热。这种增加的加热能量以等离子体负荷的形式传递给全氟碳化物，并且大部分被全氟碳化物中的冷却水吸收。然而，pfc背后的船内诊断系统也必须承受不断增加的热负荷。因此，对主动水冷却和惯性冷却的几种诊断方法进行了分析。此外，在上一次作业之前，还安装了额外的热电偶和电阻温度传感器，以监测等离子体脉冲期间pfc和其他诊断中的温度。该活动的重点是验证来自各种温度传感器的温度读数以及详细的有限元分析方法和结果。这项工作将根据预期负荷下的热分析结果和经过验证的有限元模型，为即将到来的活动设定可靠的运行限制。本文提出的第一个比较表明，对于选定的诊断插件，容器内温度测量结果与有限元分析结果之间具有良好的定量一致性。对于一些诊断，温度传感器的最高允许温度已被计算为下一个活动的操作监控的输入。对于pfc背后的诊断，温度测量和计算之间存在定性一致；其余的偏差主要是由于正确估计pfc的热渗透性的复杂性和不完全知道的装配公差。进一步验证温度测量和预期更高载荷下的有限元分析结果是验证W7-X运行极限安全性的重要一步。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Fusion Engineering and Design 工程技术-核科学技术

CiteScore

3.50

自引率

23.50%

发文量

275

审稿时长

3.8 months

期刊介绍： The journal accepts papers about experiments (both plasma and technology), theory, models, methods, and designs in areas relating to technology, engineering, and applied science aspects of magnetic and inertial fusion energy. Specific areas of interest include: MFE and IFE design studies for experiments and reactors; fusion nuclear technologies and materials, including blankets and shields; analysis of reactor plasmas; plasma heating, fuelling, and vacuum systems; drivers, targets, and special technologies for IFE, controls and diagnostics; fuel cycle analysis and tritium reprocessing and handling; operations and remote maintenance of reactors; safety, decommissioning, and waste management; economic and environmental analysis of components and systems.