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A Joule‐Thomson process with condensation and evaporation
Author(s) -
Loimer Thomas
Publication year - 2003
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200310467
Subject(s) - spark plug , saturation (graph theory) , thermodynamics , plug flow , evaporation , condensation , vapor pressure , capillary condensation , chemistry , materials science , physics , adsorption , mathematics , organic chemistry , combinatorics
The one‐dimensional flow of a fluid near saturation through a porous plug is considered. Upstream of the plug, the vapor is in the state of saturation. It is assumed that (i) the vapor cools down in a throttling process and (ii) it is in the unsaturated state downstream of the plug. At the upstream surface of the plug, the saturated vapor releases heat by partial or full condensation. If the permeability of the plug lies above a critical value the vapor condenses partially, otherwise full condensation occurs and a liquid film appears in front of the plug. In a small range of permeabilities above the critical value, the vapor condenses partially at the upstream surface, then it condenses fully at a front within the plug. Consuming the heat conducted downstream, the fluid evaporates fully at an evaporation front within the plug. The value of the critical permeability is a function of thermodynamic and transport properties of the fluid and of the thermal conductivity of the plug. The values of the permeabilities where the transitions between the different types of the process occur depend on the pressure difference across the porus plug.