Thermodynamic optimization of a vacuum multi-effect membrane distillation system for liquid desiccant regeneration

Q. Chen; M. Kum Ja; Y. Li; K. J. Chua

doi:10.1016/j.apenergy.2018.09.072

Thermodynamic optimization of a vacuum multi-effect membrane distillation system for liquid desiccant regeneration

Q. Chen, M. Kum Ja, Y. Li, K. J. Chua^*

^*Corresponding author for this work

Water Desalination & Reuse Center

Research output: Contribution to journal › Article › peer-review

31 Scopus citations

Abstract

The regenerator is one of the key components in the liquid desiccant air-conditioning system, and improvement of the regenerator performance is key to promoting the overall system energy efficiency. This study entails the investigation of a vacuum multi-effect membrane distillation system (V-MEMD) for liquid desiccant regeneration. The V-MEMD regenerator possesses the merits of high energy efficiency and zero desiccant carry-over. A thermodynamic model has been developed to study the regeneration process based on the principles of heat and mass transfer and heat and mass balances. The model is validated with experimental data, and the discrepancies are observed to be within 10% and 5% for regeneration rate and brine concentration, respectively. Employing the developed and validated model, several V-MEMD configurations have been investigated and the effects of key operating parameters are evaluated. The regenerator performance is observed to degrade at higher feed concentrations, while a higher hot water temperature promotes regeneration rate and thermal efficiency. The proposed configurations expand the operation range of the V-MEMD regenerator to greater than 40 wt% under a heat source temperature of 70 °C. Compared with existing liquid desiccant regeneration systems, the specific energy consumption is reduced by 10–50%.

Original language	English (US)
Pages (from-to)	960-973
Number of pages	14
Journal	Applied Energy
Volume	230
DOIs	https://doi.org/10.1016/j.apenergy.2018.09.072
State	Published - Nov 15 2018

Bibliographical note

Funding Information:
The authors gratefully acknowledge the generous funding from (1) the National Research Foundation (NRF) Singapore under the Competitive Research Programme (CRP) Funding Scheme (R-265-000-466-281), (2) the National Research Foundation Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and (3) the China Scholarship Council (CSC).

Funding Information:
The authors gratefully acknowledge the generous funding from (1) the National Research Foundation (NRF) Singapore under the Competitive Research Programme (CRP) Funding Scheme ( R-265-000-466-281 ), (2) the National Research Foundation Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and (3) the China Scholarship Council (CSC).

Publisher Copyright:
© 2018 Elsevier Ltd

Keywords

Liquid desiccant regeneration
Thermodynamic optimization
Vacuum multi-effect membrane distillation

ASJC Scopus subject areas

Building and Construction
Mechanical Engineering
General Energy
Management, Monitoring, Policy and Law

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.apenergy.2018.09.072

Cite this

@article{50abb13a07f346ffae229381742c228b,

title = "Thermodynamic optimization of a vacuum multi-effect membrane distillation system for liquid desiccant regeneration",

abstract = "The regenerator is one of the key components in the liquid desiccant air-conditioning system, and improvement of the regenerator performance is key to promoting the overall system energy efficiency. This study entails the investigation of a vacuum multi-effect membrane distillation system (V-MEMD) for liquid desiccant regeneration. The V-MEMD regenerator possesses the merits of high energy efficiency and zero desiccant carry-over. A thermodynamic model has been developed to study the regeneration process based on the principles of heat and mass transfer and heat and mass balances. The model is validated with experimental data, and the discrepancies are observed to be within 10% and 5% for regeneration rate and brine concentration, respectively. Employing the developed and validated model, several V-MEMD configurations have been investigated and the effects of key operating parameters are evaluated. The regenerator performance is observed to degrade at higher feed concentrations, while a higher hot water temperature promotes regeneration rate and thermal efficiency. The proposed configurations expand the operation range of the V-MEMD regenerator to greater than 40 wt% under a heat source temperature of 70 °C. Compared with existing liquid desiccant regeneration systems, the specific energy consumption is reduced by 10–50%.",

keywords = "Liquid desiccant regeneration, Thermodynamic optimization, Vacuum multi-effect membrane distillation",

author = "Q. Chen and {Kum Ja}, M. and Y. Li and Chua, {K. J.}",

note = "Funding Information: The authors gratefully acknowledge the generous funding from (1) the National Research Foundation (NRF) Singapore under the Competitive Research Programme (CRP) Funding Scheme (R-265-000-466-281), (2) the National Research Foundation Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and (3) the China Scholarship Council (CSC). Funding Information: The authors gratefully acknowledge the generous funding from (1) the National Research Foundation (NRF) Singapore under the Competitive Research Programme (CRP) Funding Scheme ( R-265-000-466-281 ), (2) the National Research Foundation Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and (3) the China Scholarship Council (CSC). Publisher Copyright: {\textcopyright} 2018 Elsevier Ltd",

year = "2018",

month = nov,

day = "15",

doi = "10.1016/j.apenergy.2018.09.072",

language = "English (US)",

volume = "230",

pages = "960--973",

journal = "Applied Energy",

issn = "0306-2619",

publisher = "Elsevier",

}

TY - JOUR

T1 - Thermodynamic optimization of a vacuum multi-effect membrane distillation system for liquid desiccant regeneration

AU - Chen, Q.

AU - Kum Ja, M.

AU - Li, Y.

AU - Chua, K. J.

N1 - Funding Information: The authors gratefully acknowledge the generous funding from (1) the National Research Foundation (NRF) Singapore under the Competitive Research Programme (CRP) Funding Scheme (R-265-000-466-281), (2) the National Research Foundation Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and (3) the China Scholarship Council (CSC). Funding Information: The authors gratefully acknowledge the generous funding from (1) the National Research Foundation (NRF) Singapore under the Competitive Research Programme (CRP) Funding Scheme ( R-265-000-466-281 ), (2) the National Research Foundation Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and (3) the China Scholarship Council (CSC). Publisher Copyright: © 2018 Elsevier Ltd

PY - 2018/11/15

Y1 - 2018/11/15

N2 - The regenerator is one of the key components in the liquid desiccant air-conditioning system, and improvement of the regenerator performance is key to promoting the overall system energy efficiency. This study entails the investigation of a vacuum multi-effect membrane distillation system (V-MEMD) for liquid desiccant regeneration. The V-MEMD regenerator possesses the merits of high energy efficiency and zero desiccant carry-over. A thermodynamic model has been developed to study the regeneration process based on the principles of heat and mass transfer and heat and mass balances. The model is validated with experimental data, and the discrepancies are observed to be within 10% and 5% for regeneration rate and brine concentration, respectively. Employing the developed and validated model, several V-MEMD configurations have been investigated and the effects of key operating parameters are evaluated. The regenerator performance is observed to degrade at higher feed concentrations, while a higher hot water temperature promotes regeneration rate and thermal efficiency. The proposed configurations expand the operation range of the V-MEMD regenerator to greater than 40 wt% under a heat source temperature of 70 °C. Compared with existing liquid desiccant regeneration systems, the specific energy consumption is reduced by 10–50%.

AB - The regenerator is one of the key components in the liquid desiccant air-conditioning system, and improvement of the regenerator performance is key to promoting the overall system energy efficiency. This study entails the investigation of a vacuum multi-effect membrane distillation system (V-MEMD) for liquid desiccant regeneration. The V-MEMD regenerator possesses the merits of high energy efficiency and zero desiccant carry-over. A thermodynamic model has been developed to study the regeneration process based on the principles of heat and mass transfer and heat and mass balances. The model is validated with experimental data, and the discrepancies are observed to be within 10% and 5% for regeneration rate and brine concentration, respectively. Employing the developed and validated model, several V-MEMD configurations have been investigated and the effects of key operating parameters are evaluated. The regenerator performance is observed to degrade at higher feed concentrations, while a higher hot water temperature promotes regeneration rate and thermal efficiency. The proposed configurations expand the operation range of the V-MEMD regenerator to greater than 40 wt% under a heat source temperature of 70 °C. Compared with existing liquid desiccant regeneration systems, the specific energy consumption is reduced by 10–50%.

KW - Liquid desiccant regeneration

KW - Thermodynamic optimization

KW - Vacuum multi-effect membrane distillation

UR - http://www.scopus.com/inward/record.url?scp=85053079623&partnerID=8YFLogxK

U2 - 10.1016/j.apenergy.2018.09.072

DO - 10.1016/j.apenergy.2018.09.072

M3 - Article

AN - SCOPUS:85053079623

SN - 0306-2619

VL - 230

SP - 960

EP - 973

JO - Applied Energy

JF - Applied Energy

ER -

Thermodynamic optimization of a vacuum multi-effect membrane distillation system for liquid desiccant regeneration

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this