TY - JOUR
T1 - Review on CFD analysis of horizontal falling film evaporators in multi-effect desalination plants
AU - Tahir, Furqan
AU - Mabrouk, Abdelnasser
AU - Koc, Muammer
N1 - Publisher Copyright:
© 2019 Desalination Publications. All rights reserved.
PY - 2019/10
Y1 - 2019/10
N2 - Desalination is a sustainable solution for water stressed countries. Among thermal desalination technologies, multi-effect desalination (MED) offers lower specific energy consumption. Falling film evaporators are extensively used in MED plants. This type of evaporator can achieve higher overall heat transfer coefficient and requires low liquid charge. The major challenges in these evaporators are (i) attaining uniform liquid load over tube bundle to avoid dry patches and scale formation, and (ii) achieving higher overall heat transfer coefficient. Although, experiments can characterize on a macroscopic scale, for microscopic understanding detailed numerical analyses is needed. This study focuses on critically analyzing the CFD works for MED falling film evaporator available in the literature. CFD modeling and methodologies have been presented followed by identification of key research gaps based on comprehensive discussion on hydrodynamics and heat/mass transfer aspects of falling film evaporators. The effects of thermophysical properties variation for broadening the operating range of MED plants, scale formation, CO2 release, liquid load maldistribution outside tubes, uneven vapor flow inside vapor box and vapor flow in co-current/cross direction need more insight. Addressing these research gaps could assist in the development of optimum evaporator design with higher overall heat transfer coefficient, improved wettability and less susceptibility to scale formation can guarantee the evaporator performance.
AB - Desalination is a sustainable solution for water stressed countries. Among thermal desalination technologies, multi-effect desalination (MED) offers lower specific energy consumption. Falling film evaporators are extensively used in MED plants. This type of evaporator can achieve higher overall heat transfer coefficient and requires low liquid charge. The major challenges in these evaporators are (i) attaining uniform liquid load over tube bundle to avoid dry patches and scale formation, and (ii) achieving higher overall heat transfer coefficient. Although, experiments can characterize on a macroscopic scale, for microscopic understanding detailed numerical analyses is needed. This study focuses on critically analyzing the CFD works for MED falling film evaporator available in the literature. CFD modeling and methodologies have been presented followed by identification of key research gaps based on comprehensive discussion on hydrodynamics and heat/mass transfer aspects of falling film evaporators. The effects of thermophysical properties variation for broadening the operating range of MED plants, scale formation, CO2 release, liquid load maldistribution outside tubes, uneven vapor flow inside vapor box and vapor flow in co-current/cross direction need more insight. Addressing these research gaps could assist in the development of optimum evaporator design with higher overall heat transfer coefficient, improved wettability and less susceptibility to scale formation can guarantee the evaporator performance.
KW - CFD
KW - Desalination
KW - Evaporator
KW - Falling film
KW - MED
UR - http://www.scopus.com/inward/record.url?scp=85073550900&partnerID=8YFLogxK
U2 - 10.5004/dwt.2019.24487
DO - 10.5004/dwt.2019.24487
M3 - Article
AN - SCOPUS:85073550900
SN - 1944-3994
VL - 166
SP - 296
EP - 320
JO - Desalination and Water Treatment
JF - Desalination and Water Treatment
ER -