Research Of Film Flow Characteristic And Mass Transfer Characteristic Over Perforated Corrugated Packings

Perforated structure and corrugation structure are applied combinedly in the structured packings,having paramount importance on mass transfer and heat transfer of film flowing over structured packings.In recent years,the study concerning exploratory packings is seldom which is trying to figure out the effect of the perforated structure on the mass transfer and heat transfer,while the researches focused on the corrugation structure are prevailing.In this study,the perforate corrugation sheet model is constructed in accordance with the realistic structured packings and the numerical simulation of flim flow and mass transfer on the perforate corrugation sheet is performed by using open source software OpenFOAM,the work carried out is manly listed as following:(1)The influence of the perforated structure on the film flowing over perforate corrugation sheet is intensively studied for the first time,and the mechanism of enhancing interaction between gas-liquid phases is revealed.The simulation result manifests that the thickness of the film is definitely changed in the near region of perforated structure,leading to the extremum of the interfacial velocity.Besides,the average velocity within film incerases,the larger vortex appears in the interface near perforated structure.(2)The effect of the apertures on the film interfacial characteristics in the perforate corrugation sheet with 10% opening ratio is explored.The research reveals that as the diameter size is growing,the extreme value of the velocity component,the interfacial area and the intensity of reciprocating movement along flowing direction become greater accordingly,the optimal operating conditions of Reynolds number are in the range of 40-50.(3)The three dimensional mass transfer performance of film is researched innovatively.The effect of the perforated structure on the concentration distribution and mass transfer coefficient is studied by the mass transfer solver compiled by OpenFOAM adopting continuous species transfer model which is able to reduce computation.The numerical simulation demonstrates that the more uniform concentration filed appeares near the perforated structure,and the film concentration in the affected region behind the perforated structure is increasing as a result of reciprocating movement on the interface.The mass transfer coefficient along the flowing direction is enlarged near the perforated structure.In addition,the numerical simulation of mass transfer on the perforate corrugation sheets of 10% opening ratio with diameter size of 2mm,4mm,6mm and 8mm is conducted,the result shows that perforate corrugation sheet with 8mm diameter size can perform the largest value of average concentration in the liquid outlet and mass transfer efficiency,reaching the best mass transfer operating condition when the liquid film spreads all over the sheet.(4)The quantitative relationship between the mass transfer and film characterists of the film flowing over perforated structure in the stable flow area is explored.The result shows that the concentration is positively linked with three components of interface velocity in exponential correlation,the velocity component which is normal to the plane placed the corrugation plate has the greatest influence on the interface concentration.The numerical model for simulating two phase film flowing and mass transfer phenomenon on the perforate corrugation sheet is constructed,making great progress in the geometric optimization of aperture of the perforated corrugated plate beginning from empirical exploration to simulation research.The related conclusion of the impact caused by changing diameter size can provide theoretical basis for the design and optimization of perforate corrugation sheet.