EFFECT OF SURFACE THERMAL PROPERTIES AND FINISH ON DROPWISE CONDENSATION
EFFECT OF SURFACE THERMAL PROPERTIES AND FINISH ON DROPWISE CONDENSATION
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DOI：
10.1016/0017-9310(67)90114-7
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发表时间：
1967-01-01
影响因子：
5.2
通讯作者：
LEE, MS
中科院分区：
文献类型：
--
作者：
GRIFFITH, P;LEE, MS
使用油酸作为促进剂，完成了 1 个大气压下蒸汽在面朝下的水平表面上滴状冷凝的传热系数测量。测试表面由直径约 2 英寸的厚圆盘组成，1.(a) 1·125 英寸铜上的金板，2.(b) 0·094 英寸锌和 1 英寸铜上的金板，3.(c) 0·12 英寸不锈钢和 1 英寸铜上的金板。发现传热系数在 2–20°F 范围内与表面过冷无关，等于：h=铜为10000Btu/h2degF，锌为h= 4500Btu/h2degF，不锈钢为h= 2000Btu/hft2degF。得出的结论是：（1）基材导热系数降低20倍，传热系数降低5倍； (2) 滴状冷凝传热系数受到传导限制，在 2–20°F 过冷范围内成核效应可以忽略不计； (3)从这些实验推断的成核效应与文献中提出的直接成核测量之间存在无法解释的差异。
Heat-transfer coefficient measurements for the dropwise condensation of steam at 1 atm on a horizontal surface facing down have been completed using oleic acid as the promoter. The test surfaces consisted of thick discs about 2 in. in diameter and1.(a) gold plate on 1·125 in of copper,2.(b) gold plate on 0·094 in of zinc and 1 in of copper,3.(c) gold plate on 0·12 in of stainless steel and 1 in of copper.The heat-transfer coefficients were found to be independent of surface subcooling in the range of 2–20°F and equal to:h= 10000Btu/h2degFfor copper,h= 4500Btu/h2degFfor zinc,h= 2000Btu/hft2degFfor stainless steel.It is concluded that: (1) a 20-fold reduction in base material thermal conductivity gives a 5-fold reduction in the heat-transfer coefficient; (2) dropwise condensation heat-transfer coefficients are conduction limited with nucleation effects negligible in the 2–20°F subcooling range; (3) unexplained discrepancies exist between the nucleation effects inferred from these experiments and the direct nucleation measurements presented in the literature.