Master's Thesis Hong Zhuang


Examination of Heat and Mass Transfer in a Spray Type Air Cooler Using Two-Phase Flow CFD Simulation

As part of the project “EnEff:Luft” the energy efficiency of the air conditioning system will be optimized
by reducing pressure drops. An approach to enhance the performance of dehumidification
and cooling in an air sprayer cooler.
In this paper the author introduces a simplified simulation model to present the heat and mass
transfer in an air sprayer cooler. The aerodynamic and thermodynamic processes in the sprayer
cooler is modelled in the Software Fluent. Choices among variations of models were made regarding
of the calculate results and efforts. The model is validated by experimental results.
The operating characteristics of air sprayer coolers are analyzed on the basis of the simulation model.
Droplet diameter, air velocity, water temperature and watermass are varied in a statistic experiment
plan to determine the dehumidifying effectiveness and the ratio of latent heat fluxes to sensible
heat fluxes, which are identified as characteristic value in operating air sprayer coolers. In addition,
trajectories of droplets are illustrated in dependence of parameters mentioned above.
In conclusion, the author provides the suggestions for operating air sprayer coolers based on the
calculated results.