TY - JOUR
T1 - Simulation CFD de la performance d'un déshumidificateur à déshydratant liquide avec des plaques lisses et rugueuses
AU - Lu, Hao
AU - Lu, Lin
N1 - Funding Information:
The work is partially supported by Hong Kong Research Grant Council through General Research Fund (PolyU 152184/17E ). The authors also appreciate the financial supports provided by the Youth Fund of Guangdong Basic and Applied Basic Research Fund (Guangdong-Guangzhou Joint Fund, No. 2019A1515110555 ), the Fundamental Research Funds for the Central Universities ( D2191930 ) and “Xinghua Scholar Talents Plan” of South China University of Technology ( K5183300 ).
Publisher Copyright:
© 2020
PY - 2021/4
Y1 - 2021/4
N2 - Liquid film pattern is crucial for mass transfer performance of falling film liquid desiccant dehumidifier (LDD). Rough plate may be effective on modifying the liquid film pattern and then enhance dehumidification efficiency of the LDD. Therefore, this study aims to investigate unsteady gas-liquid flow and dehumidification performance of falling film LDD for smooth and rough plates. The gas-liquid flow was predicted by the RNG k-ε turbulence model while the interface patterns were tracked by volume of fluid (VOF) model. The dehumidification performance was simulated by user-defined function (UDF) codes based on the penetration theory. The dynamic liquid film characteristics, the gas-liquid flow fields, the mass fraction fields and dehumidification enhancement mechanisms were analyzed and discussed. Moreover, the effects of inlet air velocity and inlet desiccant concentration on the mass transfer characteristics were investigated. The results showed that the ribbed plate can induce liquid film waves and significantly enhance dehumidification performance of the falling film LDD. The dehumidification enhancement can reach 30.9% by the rough plate when inlet air velocity is 0.5 m s−1 and inlet desiccant concentration is 30%, compared with the smooth plate case. The enhancement mechanisms of dehumidification by the rough plate include the liquid film waves, the flow vortex and high-value TKE near the gas-liquid interface. The outlet mass fraction of water vapor is decreased when the inlet air velocity is lower and the inlet desiccant concentration is higher. The rough plate is effective for the mass transfer enhancement for different inlet air velocity and desiccant concentration.
AB - Liquid film pattern is crucial for mass transfer performance of falling film liquid desiccant dehumidifier (LDD). Rough plate may be effective on modifying the liquid film pattern and then enhance dehumidification efficiency of the LDD. Therefore, this study aims to investigate unsteady gas-liquid flow and dehumidification performance of falling film LDD for smooth and rough plates. The gas-liquid flow was predicted by the RNG k-ε turbulence model while the interface patterns were tracked by volume of fluid (VOF) model. The dehumidification performance was simulated by user-defined function (UDF) codes based on the penetration theory. The dynamic liquid film characteristics, the gas-liquid flow fields, the mass fraction fields and dehumidification enhancement mechanisms were analyzed and discussed. Moreover, the effects of inlet air velocity and inlet desiccant concentration on the mass transfer characteristics were investigated. The results showed that the ribbed plate can induce liquid film waves and significantly enhance dehumidification performance of the falling film LDD. The dehumidification enhancement can reach 30.9% by the rough plate when inlet air velocity is 0.5 m s−1 and inlet desiccant concentration is 30%, compared with the smooth plate case. The enhancement mechanisms of dehumidification by the rough plate include the liquid film waves, the flow vortex and high-value TKE near the gas-liquid interface. The outlet mass fraction of water vapor is decreased when the inlet air velocity is lower and the inlet desiccant concentration is higher. The rough plate is effective for the mass transfer enhancement for different inlet air velocity and desiccant concentration.
KW - Heat and mass transfer
KW - Liquid desiccant dehumidifier
KW - Numerical simulation
KW - Rough plate
UR - http://www.scopus.com/inward/record.url?scp=85099935492&partnerID=8YFLogxK
U2 - 10.1016/j.ijrefrig.2020.12.012
DO - 10.1016/j.ijrefrig.2020.12.012
M3 - Journal article
AN - SCOPUS:85099935492
SN - 0140-7007
VL - 124
SP - 1
EP - 12
JO - International Journal of Refrigeration
JF - International Journal of Refrigeration
ER -