Condensation Heat Transfer in the Presence of a Noncondensable Gas
Condensation Heat Transfer in the Presence of a Noncondensable Gas
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DOI：
10.1115/1.3688714
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发表时间：
1964-08
影响因子：
--
通讯作者：
E. Sparrow;S. Lin
中科院分区：
文献类型：
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作者：
E. Sparrow;S. Lin
本文提出了一种计算不凝性气体冷凝传热的理论。该分析仅基于守恒定律，不利用经验数据。结果表明，在大量的蒸汽中存在非常少量的不凝性气体可以导致在液-气界面处的不凝性的大量积累。这种积聚的结果是界面处的蒸气分压降低。这反过来又降低了蒸汽冷凝的温度，并减少了有效的热驱动力。不凝物的存在可能会使传热减少50%以上。分析的预测进行了比较与冷凝传热测量蒸汽与空气作为不可冷凝物。理论与实验结果符合较好。
A theory has been devised for predicting condensation heat transfer in the presence of a noncondensable gas. The analysis is based on the conservation laws alone and does not utilize empirical data. It is shown that the presence of a very small amount of noncondensable gas in the bulk of the vapor can cause a large buildup of the noncondensable at the liquid-vapor interface. A consequence of this buildup is that the partial pressure of the vapor at the interface is reduced. This, in turn, lowers the temperature at which the vapor condenses and diminishes the effective thermal driving force. Heat-transfer reductions of well over fifty percent may be brought about by the presence of the noncondensable. The predictions of the analysis are compared with condensation heat-transfer measurements for steam with air as noncondensable. The agreement between theory and experiment is satisfactory.