Research on Calculation Method of Leakage Rate of Graphite Gasket Seal
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摘要: 为完善核级主设备密封分析及设计方法,基于稳压器人孔密封结构建立了密封数值分析模型,对石墨垫片密封接触应力进行了分析研究;结合平行圆板流动模型和多孔介质渗流模型建立了石墨垫片密封质量泄漏率理论预测模型;基于理论预测模型计算了设计工况、试验工况和启动瞬态工况下的质量泄漏率,对主要影响参数进行了分析和讨论。研究结果表明,石墨垫片密封接触应力沿周向分布较为均匀,而石墨环沿径向的中间区域接触应力值略低于石墨环两侧;在温度和压力上升瞬态中,密封接触应力随时间呈现出下降的规律,密封质量泄漏率与接触应力呈负相关,增大密封接触应力可以降低质量泄漏率,但降低效率逐渐减小,减小粗糙度可以显著降低质量泄漏率。本文分析方法可为核级主设备密封泄漏率分析和紧密度评价提供重要参考。Abstract: In order to improve the seal analysis and design method of nuclear grade main equipment, a numerical analysis model of the seal is established based on the voltage regulator manhole seal structure, and the contact stress of the graphite gasket seal is analyzed and studied; The theoretical prediction model of graphite gasket seal mass leakage rate is established by combining the parallel circular plate flow model and porous medium seepage model; Based on the theoretical prediction model, the mass leakage rate under design conditions, test conditions and startup transient conditions is calculated, and the main influencing parameters are analyzed and discussed. The results show that the contact stress of the graphite gasket seal is uniformly distributed along the circumferential direction, while the contact stress in the radial middle region of the graphite ring is slightly lower than that on both sides of the graphite ring; In the transient state of rising temperature and pressure, the seal contact stress decreases with time, and the seal mass leakage rate is negatively correlated with the contact stress. Increasing the seal contact stress can reduce the mass leakage rate, but the efficiency decreases gradually. Reducing the roughness can significantly reduce the mass leakage rate.The analysis method in this paper can provide an important reference for seal leakage rate analysis and tightness evaluation of nuclear grade main equipment.
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Key words:
- Voltage regulator manhole /
- Graphite gasket /
- Sealing contact stress /
- Mass leakage rate
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表 1 质量泄漏率计算结果
Table 1. Calculation Result of Mass Leakage Rate
工况 SG/MPa QM/(10−8kg·s−1) 设计工况 49.14 2.68 试验工况 48.42 2.76 -
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