MODELING OF HEAT AND MASS-TRANSFER IN A HORIZONTAL-TUBE FALLING-FILM EVAPORATOR FOR WATER DESALINATION

Citation
K. Bourouni et al., MODELING OF HEAT AND MASS-TRANSFER IN A HORIZONTAL-TUBE FALLING-FILM EVAPORATOR FOR WATER DESALINATION, Desalination, 116(2-3), 1998, pp. 165-183
Citations number
21
Categorie Soggetti
Water Resources","Engineering, Chemical
Journal title
ISSN journal
00119164
Volume
116
Issue
2-3
Year of publication
1998
Pages
165 - 183
Database
ISI
SICI code
0011-9164(1998)116:2-3<165:MOHAMI>2.0.ZU;2-T
Abstract
In this study, heat and mass transfer in a horizontal-tube falling-fil m evaporator, destined to be used in a desalination plant functioning by aero-evapo-condensation process, is studied theoretically. The pres ent exchanger is made of polypropylene and it was designed to work at low temperatures (60 degrees C-90 degrees C) utilising geothermal ener gy. The one-dimensional model developed, uses basic aerodynamic, hydro dynamic and heat/mass transfer information to predict the performance of the exchanger. The predicted transfer characteristics obtained from the simulations are compared with experimental data. From this compar ison it can be learnt that the model is well able to predict the trend s of heat and mass characteristics of the evaporator. However, in low liquid film now rate conditions, the model was found to overpredict th e transfer characteristics slightly and the reasons for the difference s are discussed. The influence of the different thermal, hydrodynamic and geometric parameters on the evaporator performances was investigat ed. The variations of the distilled water amount inside the exchanger are analysed. The results are used to determine the operational condit ions corresponding to a maximum evaporative performances. The model wa s also used to optimise the different components of the exchanger.