Analysis of the spray field development on a vertical surface during water spray-quenching using a flat spray nozzle
Analysis of the spray field development on a vertical surface during water spray-quenching using a flat spray nozzle
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DOI：
10.1016/j.applthermaleng.2008.08.007
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发表时间：
2009-05
影响因子：
6.4
通讯作者：
W. Vorster;S. Schwindt;J. Schupp;A. Korsunsky
中科院分区：
文献类型：
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作者：
W. Vorster;S. Schwindt;J. Schupp;A. Korsunsky
本研究的目的是（i）对瞬态喷雾冷却操作期间大型加热表面上的流动发展进行实验空间和时间分辨测量，以及（ii）研究和讨论喷雾冷却机制的影响，例如气泡形成和冷却流体的流场发展，以及这如何影响传热。将石英板加热至500°C以上，然后用过冷至80K的加压水喷洒。以 3000Hz 的速率收集淬火过程的高速图像，从而可以在板冷却到该位置流体的莱顿弗罗斯特温度以下时跟踪淬火前沿的运动。观察表明，一旦板上达到莱顿弗罗斯特温度，液滴与表面相互作用的相对重要性就会降低：人们发现，一旦水接触表面，水池就会迅速形成，随着水池淹没加热的表面，水池会变得更大。为了更准确地描述这些相互作用，对板上的空间流动发展和传热进行了比较。这些信息不仅为过程模拟提供了重要的输入，而且对于开发描述由于喷水而导致的加热部件润湿的流固相互作用的理论模型也很有用。
The aims of this study were (i) to conduct experimental spatially and time-resolved measurements of flow development on large heated surfaces during transient spray cooling operations and (ii) to investigate and discuss the influence of spray cooling mechanisms such as bubble formation and the flow field development of the cooling fluid and how this affects heat transfer. Quartz plates were heated to above 500°C and then sprayed with pressurised water subcooled to 80K. High speed images of the quench process were collected at a rate of 3000Hz making it possible to track the movement of the quench front as the plate cools below the Leidenfrost temperature of the fluid at that location. Observations showed that the relative importance of droplet-surface interactions decreases once the Leidenfrost temperature is reached on the plate: It was found that once the water contacts the surface, a water pool develops rapidly which grows larger as the pool floods the heated surface. Comparisons between the spatial flow development and heat transfer on the plate are made in order to describe these interactions more accurately. This information not only provides crucial input into process simulations, but is also useful to develop theoretical models of fluid–solid interaction describing the wetting of a heated component due to water spraying.