Towards understanding the effects of irradiation on quenching heat transfer

Nucleate boiling is inseparably connected with our everyday life. It is not only utilized in simple tasks like cooking, but it is also important for applications on various scales, ranging from enormous nuclear power plants to miniature microelectronics. This widespread integration is the result of its ability for effective heat transfer at low temperature differences between the heated surface and the surrounding fluid. The surface wettability undoubtedly influences the boiling heat transfer, but the observed behaviour cannot be explained without taking into account the surface topography and chemical modifications due to intense boiling processes. This chapter demonstrates how nucleate boiling enhancement can be achieved on surfaces with various wetting properties and specific micro/nano topographical features, fabricated using a straightforward, robust and scalable laser texturing approach. We discuss the basics of nucleate boiling and how it is affected by surface wettability; provide a fundamental background of laser surface engineering and its ability to achieve extreme wetting properties; and finally demonstrate the applicability of the laser-textured surfaces in enhancing and controlling nucleate pool boiling of different fluids. We show how laser surface engineering decreases the wettability effects on the key boiling parameters andin this wayensures more stable heat transfer performance.

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“…When surfaces are exposed to ionizing radiation, this also significantly influences surface wettability [161,171,172].…”

Section: Fabrication Of Multiscale -Cavities By Laser Texturingmentioning

confidence: 99%

Laser Surface Engineering for Boiling Heat Transfer Applications

Zupančič

Gregorčič

2021

Materials With Extreme Wetting Properties

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“…With all the surface characterization details discussed above, it can be reasonably concluded that gamma irradiation, even at room temperature, causes localized corrosion which increased with net dose, which, was also responsible for the increase in wettability and surface energy. Increased wettability is well known to improve two phase heat transfer and hence it can be reasonably concluded that considering this effect of ionizing irradiation may become critical in determining CHF and thermal operation limits (a margin that might have been missed in calculations so far), considering the fact that gamma rays are emitted continuously in a nuclear reactor [4]. On the other hand, while the increased corrosion due to gamma irradiation is well-documented for Zircaloy and Steel based alloys in the nuclear community, its impact on advanced cladding materials such as SiC is of significant interest [12].…”

Section: Surface Morphology and Chemistry Studiesmentioning

confidence: 99%

“…Specifically, the role of gamma irradiation on surface wettability/surface energy change by a process known as Radiation Induced Surface Activation (RISA) [2,3] has been demonstrated by several researchers. Previously, the authors published their findings on the possibility of surface oxidation as a result of gamma irradiation which improved surface wettability and the Leidenfrost temperature on Zircaloy-4 surfaces [4].…”

Section: Introductionmentioning

confidence: 99%

Impact of Ionizing Irradiation on Surface Wettability: Fundamentals and Application in Engineering Superhydrophobic Surfaces

Seshadri¹,

Philips²,

Forrest³

et al. 2020

Transactions of the American Nuclear Society - Volume 123

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“…鉴于上述原因, 研究者致力于研究如何抑制Lei-denfrost现象. 目前已提出多种方法, 如利用γ射线辐照表面 [5] 、紫外/臭氧清洗表面 [6] 、改变液滴组分 [7] 、改造表面结构 [8~11] 、低频振动 [12] 、高频声波 [13] 、电场抑 ; 而交流电场除电压外, 还可改变频率, 频率越低, 抑制效果越好 [15] . (2) 电极结构影响抑制Leidenfrost现象的临界电压.…”

Section: 实际工业应用而言 Leidenfrost现象大大降低了换热设unclassified