Transient heat transfer behavior of water spray evaporative cooling on a stainless steel cylinder with structured surface for safety design application in high temperature scenario
Transient heat transfer behavior of water spray evaporative cooling on a stainless steel cylinder with structured surface for safety design application in high temperature scenario
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DOI：
10.1007/s00231-016-1830-5
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发表时间：
2017-02
影响因子：
2.2
通讯作者：
M. Aamir;Q. Liao;Wang Hong;Z. Xun;Si-hong Song;M. Sajid
中科院分区：
文献类型：
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作者：
M. Aamir;Q. Liao;Wang Hong;Z. Xun;Si-hong Song;M. Sajid
结构化表面喷雾冷却的高传热性能可能是提高装置安全性的一项额外措施，以应对因温度快速升高而造成的任何威胁。本实验研究的目的是探讨不同喷涂条件和表面温度下结构化表面的传热性能。使用两个圆柱形不锈钢样品，一个具有金字塔销结构化表面，另一个具有光滑表面。当入口压力为 1.0 MPa 时，样品初始平均温度分别为 600、700、800 和 900 °C，估计表面热通量分别为 3.60、3.46、3.93 和 4.91 MW/m2。对于结构化表面，在 900 °C 入口压力为 0.7 MPa 时，估计最大冷却速率为 507 °C/s，而对于光滑表面，在 700 °C、1.0 MPa 时，最大冷却速率为 356 °C/s。在初始样品温度为 900 °C 的喷雾冷却过程中，结构化表面的热交换性能更好，入口压力分别为 0.4、0.7、1.0 和 1.3 MPa，表面热通量相对于光滑表面增加了 1.9、1.56、1.66 和 1.74 倍。对于光滑表面，当初始样品温度从 600°C 增加到 900°C 时，观察到估计热通量呈下降趋势。采用基于温度的函数指定方法来估计表面热通量和表面温度。关于结构化表面喷雾冷却技术的应用，以确保不锈钢结构在极高温度下的安全，例如核安全容器和液化天然气储罐，已发表的工作有限。
High heat transfer performance of spray cooling on structured surface might be an additional measure to increase the safety of an installation against any threat caused by rapid increase in the temperature. The purpose of present experimental study is to explore heat transfer performance of structured surface under different spray conditions and surface temperatures. Two cylindrical stainless steel samples were used, one with pyramid pins structured surface and other with smooth surface. Surface heat flux of 3.60, 3.46, 3.93 and 4.91 MW/m2are estimated for sample initial average temperature of 600, 700, 800 and 900 °C, respectively for an inlet pressure of 1.0 MPa. A maximum cooling rate of 507 °C/s was estimated for an inlet pressure of 0.7 MPa at 900 °C for structured surface while for smooth surface maximum cooling rate of 356 °C/s was attained at 1.0 MPa for 700 °C. Structured surface performed better to exchange heat during spray cooling at initial sample temperature of 900 °C with a relative increase in surface heat flux by factor of 1.9, 1.56, 1.66 and 1.74 relative to smooth surface, for inlet pressure of 0.4, 0.7, 1.0 and 1.3 MPa, respectively. For smooth surface, a decreasing trend in estimated heat flux is observed, when initial sample temperature was increased from 600 to 900 °C. Temperature-based function specification method was utilized to estimate surface heat flux and surface temperature. Limited published work is available about the application of structured surface spray cooling techniques for safety of stainless steel structures at very high temperature scenario such as nuclear safety vessel and liquid natural gas storage tanks.