NUMERICAL STUDY OF VACUUM-AIDED SPRAY FLASH DESALINATION

Guangyu Guo, Hongling Deng, Chao Zhu, Zhiming Ji

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Spray flash desalination is an advanced distillation method by space flash evaporation of over-saturated multi-component droplets and/or ligaments to generate the distilled condensable vapor. Vacuum-aided spray flash is spraying the superheated and atomized droplets into a depressurized chamber whose low pressure is maintained by a continued vacuum extraction of vapors, a process of high thermal non-equilibrium and of high non-uniformity in phase changes and transport. This study presents a CFD numerical simulation to quantify some of the non-equilibrium and non-uniformity characteristics in vacuum-aided spray flash distillation, especially on the temperature difference and the thermal re-equilibrium tendency between vapor and liquid residue. Since ANSYS Fluent lacks the mathematic model of self-heat supplied evaporation in discrete phase modeling (DPM), a pressure-driven flash evaporation model is proposed and implemented into CFD via User-defined functions (UDF). Preliminary results meet a good agreement with experiments. It revealed the non-uniformed characteristics of the vapor phase (i.e., distributions of temperature and velocity), as well as the thermal non-equilibrium between the two phases. It also suggests that the salt fraction within droplets will result in negative impacts on evaporating efficiency and evaporating rate during the process.

Original languageAmerican English
Title of host publication5th-6th Thermal and Fluids Engineering Conference, TFEC 2021
PublisherBegell House Inc.
Pages777-787
Number of pages11
ISBN (Electronic)9781567005172
DOIs
StatePublished - 2021
Event5th-6th Thermal and Fluids Engineering Conference, TFEC 2021 - Virtual, Online
Duration: May 26 2021May 28 2021

Publication series

NameProceedings of the Thermal and Fluids Engineering Summer Conference
Volume2021-May

Conference

Conference5th-6th Thermal and Fluids Engineering Conference, TFEC 2021
CityVirtual, Online
Period5/26/215/28/21

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes
  • Electrical and Electronic Engineering

Keywords

  • CFD
  • UDF
  • multi-component evaporation
  • non-equilibrium process
  • spray flash desalination

Fingerprint

Dive into the research topics of 'NUMERICAL STUDY OF VACUUM-AIDED SPRAY FLASH DESALINATION'. Together they form a unique fingerprint.

Cite this