Effects of Electric Field on Saturated Vapor Pressure

摘要

Vapor pressure and boiling point are important thermodynamic properties of vapor-liquid equilibrium (VLE). Experiments showed that the electrostatic field can shift the VLE, and thus it is desirable to understand this physical mechanism for applications. Applying the expression of electrohydrodynamic (EHD) force on the phase interface, an expression of dielectric pressure caused by the presence of electrostatic field is derived, which is sensitive to the direction of the electric field. An expression of chemical potential including the influence of electrostatic field was derived from the fundamental thermodynamic equations and the definition of chemical potential. Then, based on the principle of phase equilibrium, Kelvin equation was extended to include the effect of the electrostatic field. Finally, an expression of vapor pressure with the influence of the electrostatic field was derived by a combination of the dielectric pressure and the extended Kelvin equation, which is also the relation between vapor pressure and boiling point under the action of the electric field. The characteristics of the vapor pressure were discussed, and an improved novel heat transfer device was proposed.

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