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Condensation

Condensation - Not available for download

M. A. Kedzierski, J. C. Chato, and T. J. Rabas, "Condensation" Chapter 15

in Handbook of Heat Transfer, edited by Allan D. Kraus and Adrian Bejan, John Wiley & Sons, Inc., 2003.
Keywords:
condensation , convective condensation , dropwise condensation , filmcondensation , heat transfer , NIST , vapor-space condensation
Abstract:
Condensation is the process by which a vapor is converted to its liquid state. Because fo the large internal energy difference between the liquid and vapor states, a significant amount of heat can be released during the condensation process. For this reason the condensation process is used to many thermal systems. In general, a vapor will condense to liquid when it is cooled sufficiently or comes in contact with something (e.g., a solid or another fluid) that is below its equilibrium temperature. This chapter is primarily concerned with convective condensation (condensation of a flowing vapor in a passage) and vapor-space condensation (condensation of stagnate vapor onto a surface). Film condensation occurs when the condensate completely wets the surface in a continuous liquid film and can be associated with either convective or vapor-space condensation. Dropwise condensation - usually associated with vapor-space condensation - occurs when the condensate "beads up" on the surface into drops of liquid as a consequence of the liquid's lack of affinity for the surface. Heat transfer coefficients for dropwise condensation can be one-to-two orders of magnitude greater than that for film condensation. Unfortunately, dropwise condensation is not easily sustained in practice.

Building and Fire Research Laboratory
National Institute of Standards and Technology
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Last updated: 4/21/2005