Heat and mass transfer in low-temperature heat exchanger pipes

Study of entrainment of drops of coolant by wet vapor in a heat-pipe vaporizer

“…Substituting Eqs. ( 7), ( 12), (15), and ( 16) into the equation for the mass of the entrained drops (6), we obtain m C18~vV/~ ~P~g ( 4~-~vZc ) (pv~) 4…”

“…However, under real conditions the vapor will contain drops of liquid. There may be different reasons for the presence of these dopes: mechanical spraying as a result of vaporization [6]; interaction of the moving flow of vapor with the surface of the condensate [7]; a change in the thermodynamic parameters of the flow [8] leading to volume condensation of the vapor; organization of return of the condensate in the form of a disperse phase [6], such as in coaxial centrifugal heat pipes and evaporative thermosiphons; artificial spraying of drops into the vapor channel to organize circulation of the coolant in the vapor or liquid phase, such as in steam-life heat pipes. Thus, a more correct formulation of the problem would allow for the two-phase state of mass flow in the vapor channel.…”

Performance limits of low-temperature heat pipes

“…For this reason, a direct experimental verification of the fundamental integral relation (1) for heat pipes under various operating conditions was deemed both necessary and useful.…”

“…A performance analysis of low-temperature heat pipes [1,2,6] has revealed, along with "hydrodynamic locking" (a limit on power, according to Eq. (1)), also a limit imposed by "locking" in the capillary structure.…”