Abstract In this study, irradiation effects of CHF on bare and porous honeycomb surfaces in downward-face saturated pool boiling with different downward inclination angles were investigated. After irradiation, the hydrophilicity of copper and porous honeycomb structure increased compared to that of the non-irradiated surface. For bare surface cases, CHF enhancement cannot be observed at downward inclination angles of 10° and 20° after irradiation. This is likely to be because under higher downward inclination, the bubble film departure frequency (BFDF) is larger than that of the 5° case. So there is no enough time for water to be supplied to the surface, which weakens the effect of vapor-liquid mixture area, leading to an unchanged CHF performance. In honeycomb surface cases, no CHF enhancement is observed after irradiation. This is because the macro structure became the dominant factor to determine bubble behavior, which resulted in no further enhancement in CHF. Irradiation cannot affect BFDF values for both bare and honeycomb surface. BFDF is determined by the macro structure of the surface, instead of the micro structure of the surface. The results also show that CHF is not deteriorated by irradiation in some cases, which is a good news to real-world nuclear power plants.

中文翻译：

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CHF对下表面饱和池沸腾裸多孔蜂窝表面的辐照效应

摘要 在本研究中，研究了 CHF 对不同向下倾角的向下饱和池沸腾中裸露和多孔蜂窝表面的辐照效应。辐照后，与未辐照表面相比，铜和多孔蜂窝结构的亲水性增加。对于裸露的表面情况，辐照后向下倾角为 10°和 20°时无法观察到 CHF 增强。这可能是因为在较高的向下倾角下，气泡膜偏离频率（BFDF）大于 5° 的情况。因此没有足够的时间将水供应到表面，这削弱了汽液混合区的影响，导致 CHF 性能不变。在蜂窝表面情况下，辐照后没有观察到 CHF 增强。这是因为宏观结构成为决定气泡行为的主导因素，导致 CHF 没有进一步增强。辐照不会影响裸露和蜂窝表面的 BFDF 值。BFDF 是由表面的宏观结构决定的，而不是由表面的微观结构决定的。结果还表明，在某些情况下，CHF 不会因辐照而恶化，这对现实世界的核电站来说是个好消息。