Abstract As part of its design certification effort, NuScale Power has completed a series of low mass flux [<1000 kg/(m2‧s)] critical heat flux (CHF) tests for a wide range of pressures at Stern Laboratories in Canada. Earlier studies have demonstrated that under annular flow conditions, disturbance waves with circulating vortices traverse the rod surface. The disturbance wave slides over and significantly influences energy transport in the co-current vapor-liquid sublayer at the heater interface. This paper describes the mechanisms leading to the onset of CHF in a vertical rod bundle experiencing annular mist flow conditions. The paper presents a new CHF model that implements a local disturbance wave velocity. A comparison of the model to the U1 CHF data set from Stern Laboratories shows excellent agreement over the full range of annular mist flows, pressures, and subcooled conditions for the specific spacer grids implemented in the study.

中文翻译：

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棒束中垂直环形雾流条件的临界热通量模型

摘要 作为其设计认证工作的一部分，NuScale Power 已在加拿大 Stern 实验室完成了一系列低质量通量 [<1000 kg/(m2·s)] 临界热通量 (CHF) 测试，适用于各种压力。早期的研究表明，在环形流动条件下，带有循环涡流的扰动波会穿过杆表面。扰动波滑过并显着影响加热器界面处并流汽液亚层中的能量传输。本文描述了在经历环形雾流条件的垂直杆束中导致 CHF 发生的机制。本文提出了一种新的 CHF 模型，该模型实现了局部扰动波速度。