Experimental studies of critical heat flux for low flow of water in vertical annuli at near atmospheric pressure
Experimental studies of critical heat flux for low flow of water in vertical annuli at near atmospheric pressure
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DOI：
10.1016/0017-9310(88)90161-5
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发表时间：
1988-11
影响因子：
5.2
通讯作者：
M. El-Genk;S. J. Haynes;Kim Sung-ho
中科院分区：
文献类型：
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作者：
M. El-Genk;S. J. Haynes;Kim Sung-ho
对常压（0.118 MPa）附近垂直环空中小流量水的临界热流密度（CHF）进行了实验测量。CHF数据收集的水入口过冷度范围为44 K（或182 kJ kg−1）至75 K（或312 kJ kg−1），质量通量范围为0至260 kg m−2s−1。CHF值从零入口流量时的155 kW m− 2变化到水质量通量为260 kg m−2s−1时的最大值1418 kW m− 2。根据CHF时发生的流动转变对数据进行了分类和关联。两个CHF关联式，一个用于段塞-搅动和搅动-环状流过渡，另一个用于环状-环状雾流过渡。还测量了初始流动时的热通量，发现其变化范围从最小环隙（环隙比= 1.575）中CHF值的约40%的最小值到其他较大环隙（环隙比= 1.72和2.0）中CHF值的约88%的最大值。结果还表明，随着水质量流量或入口过冷度的增加，起动时的热流密度增加。使用Block和沃利斯的溢流相关性，零入口流量的CHF值预测在±25%以内。
Experiments are performed to measure the critical heat flux (CHF) for low flow of water in vertical annuli near atmospheric pressure (0.118 MPa). CHF data are collected for water inlet subcooling ranging from 44 K (or 182 kJ kg−1) to 75 K (or 312 kJ kg−1), and mass fluxes from 0 to 260 kg m−2s−1. The CHF values vary from 155 kW m−2for zero inlet flow to a maximum of 1418 kW m−2for a water mass flux of 260 kg m−2s−1. The data are classified and correlated according to the flow transition which occurred at CHF. Two CHF correlations are developed, one for the slug-churn and the churn-annular flow transitions and the other for the annular-annular mist flow transition. The heat flux at incipient flow chugging is also measured and found to vary from a minimum of about 40% of the CHF values in the smallest annulus (annulus ratio = 1.575) to a maximum of approximately 88% of CHF in the other larger annuli (annulus ratio = 1.72 and 2.0). Results also show that the heat flux at incipient chugging increases as either the water mass flux or inlet subcooling increases. The CHF values for zero inlet flow are predicted within ±25% using Block and Wallis' flooding correlation.