Lithium bromide solution is used as a desiccant in air dehumidification systems. Liquid desiccant is a solution that facilitates the removal of humidity directly from the air. In this work, effectiveness of a LiBr based air dehumidifier was studied by correlating the vapor–liquid equilibrium data with a proposed thermodynamic model. For this, the nonelectrolyte Wilson nonrandom factor (N-Wilson-NRF) model and the Pitzer–Debye–Huckel formula were used to represent the contribution of the short and the long range ion–ion interactions. In particular, the proposed model assumed that the electrolyte solution is treated as a mixture of undissociated ion pairs and solvent molecules. The proposed equation of this study is valid for the temperature range of 20–35 °C and concentration range of 0.40–0.60 kg/kg. This relation was employed to estimate the equivalent humidity ratio, and then, the humidity ratio from the previous step was used to calculate the effectiveness of a LiBr based dehumidifier. The response surface methodology (RSM) was applied for the design and analysis of the dehumidification experiments. A quadratic model was implemented to predict the dehumidification effectiveness. This model studies the implications of four primary variables on the effectiveness of a dehumidification process. The optimal values to achieve the maximum effectiveness were found to be 32.5 °C for the air temperature, 0.0210 kg/kg for the air humidity ratio, 2.17 for the mass flow rate ratio, and finally, 0.50 kg/kg for the desiccant concentration. These values gave the dehumidification effectiveness of 0.544. The result of the model was in good agreement with the experimental value 0.542, thus verifying the accuracy of the proposed model.

References

References
1.
Chen
,
X. Y.
,
Li
,
Z.
,
Jiang
,
Y.
, and
Qu
,
K. Y.
,
2006
, “
Analytical Solution of Adiabatic Heat and Mass Transfer Process in Packed-Type Liquid Desiccant Equipment and Its Application
,”
Sol. Energy
,
80
(
11
), pp.
1509
1516
.
2.
Ge
,
G.
,
Xiao
,
F.
, and
Niu
,
X.
,
2011
, “
Control Strategies for a Liquid Desiccant Air-Conditioning System
,”
Energy Build.
,
43
(
1
), pp.
1499
1507
.
3.
Koronaki
,
I. P.
,
Christodoulaki
,
R. I.
,
Papaefthimiou
,
V. D.
, and
Rogdakis
,
E. D.
,
2013
, “
Thermodynamic Analysis of a Counter Flow Adiabatic Dehumidifier With Different Liquid Desiccant Materials
,”
Appl. Therm. Eng.
,
50
(
1
), pp.
361
373
.
4.
Babakhani
,
D.
, and
Soleymani
,
M.
,
2010
, “
Simplified Analysis of Heat and Mass Transfer Model in Liquid Desiccant Regeneration Process
,”
J. Taiwan Inst. Chem. Eng.
,
41
(
3
), pp.
259
267
.
5.
Daou
,
K.
,
Wang
,
R. Z.
, and
Xia
,
Z. Z.
,
2006
, “
Desiccant Cooling Air Conditioning: A Review
,”
Renewable Sustainable Energy Rev.
,
10
(
2
), pp.
55
77
.
6.
Bassuoni
,
M. M.
,
2014
, “
Experimental Performance Study of a Proposed Desiccant Based Air Conditioning System
,”
J. Adv. Res.
,
5
(
1
), pp.
87
95
.
7.
Lof
,
G. O. G.
,
1955
, “
Cooling With Solar Energy
,”
World Symposium on Applied Solar Energy
,
Phoenix, AZ
, pp.
171
189
.
8.
Liu
,
X. H.
,
Yi
,
X. Q.
, and
Jiang
,
Y.
,
2011
, “
Mass Transfer Performance Comparison of Two Commonly Used Liquid Desiccants: LiBr and LiCl Aqueous Solutions
,”
Energy Convers. Manage.
,
52
(
1
), pp.
180
190
.
9.
Kinsara
,
A. A.
,
Elsayed
,
M.
, and
Al-Rabghi
,
O. M.
,
1996
, “
Proposed Energy-Efficient Air-Conditioning System Using Liquid Desiccant
,”
Appl. Therm. Eng.
,
16
(
10
), pp.
791
806
.
10.
Conde
,
M. R.
,
2004
, “
Properties of Aqueous Solutions of Lithium and Calcium Chloride: Formulations for Use in Air Conditioning Equipment Design
,”
Int. J. Therm. Sci.
,
43
(
4
), pp.
367
382
.
11.
Fumo
,
N.
, and
Goswami
,
D. Y.
,
2002
, “
Study of an Aqueous Lithium Chloride Desiccant System: Air Dehumidification and Desiccant Regeneration
,”
Sol. Energy
,
72
(
4
), pp.
351
361
.
12.
Gao
,
W. Z.
,
Liu
,
J. H.
,
Cheng
,
Y. P.
, and
Zhang
,
X. L.
,
2012
, “
Experimental Investigation on the Heat and Mass Transfer Between Air and Liquid Desiccant in a Cross-Flow Dehumidifier
,”
Renewable Energy
,
37
(
1
), pp.
117
123
.
13.
Ren
,
C. Q.
,
2008
, “
Corrections to the Simple Effectiveness-NTU Method for Counterflow Cooling Towers and Packed Bed Liquid Desiccant–Air Contact Systems
,”
Int. J. Heat Mass Transfer
,
51
(
1–2
), pp.
237
245
.
14.
Jain
,
S.
,
Dhar
,
P. L.
, and
Kaushik
,
S. C.
,
2000
, “
Experimental Studies on the Dehumidifer and Regenerator of a Liquid Desiccant Cooling System
,”
Appl. Therm. Eng.
,
20
(
3
), pp.
253
267
.
15.
Gandhidasan
,
P.
,
2004
, “
A Simplified Model for Air Dehumidification With Liquid Desiccant
,”
Sol. Energy
,
76
(
4
), pp.
409
416
.
16.
Langroudi
,
L. O.
,
Palavanzadeh
,
H.
, and
Mousavi
,
S. M.
,
2014
, “
Statistical Evaluation of a Liquid Desiccant Dehumidification System Using RSM and Theoretical Study Based on the Effectiveness NTU Model
,”
J. Ind. Eng. Chem.
,
20
(
5
), pp.
2975
2983
.
17.
Zhang
,
L.
,
Hihara
,
E.
,
Matsuoka
,
F.
, and
Dang
,
C.
,
2010
, “
Experimental Analysis of Mass Transfer in Adiabatic Structured Packing Dehumidifier/Regenerator With Liquid Desiccant
,”
Int. J. Heat Mass Transfer
,
53
(
13–14
), pp.
2856
2863
.
18.
Liu
,
X. H.
,
Qu
,
K. Y.
, and
Jiang
,
Y.
,
2006
, “
Empirical Correlations to Predict the Performance of the Dehumidifier Using Liquid Desiccant in Heat and Mass Transfer
,”
Renewable Energy
,
31
(
10
), pp.
1627
1639
.
19.
Pahlavanzadeh
,
H.
, and
Nooriasl
,
P.
,
2012
, “
Experimental and Theoretical Study of Liquid Desiccant Dehumidification System by Using of Effectiveness Model
,”
ASME J. Therm. Sci. Eng. Appl.
,
4
(
1
), p.
011008
.
20.
Jafari
,
A.
,
Tynja la
,
T.
,
Mousavi
,
S. M.
, and
Sarkomaa
,
P.
,
2008
, “
CFD Simulation and Evaluation of Controllable Parameters Effect on Thermomagnetic Convection in Ferrofluids Using Taguchi Technique
,”
Comput. Fluids
,
37
(
10
), pp.
1344
1353
.
21.
Patil
,
M. S.
,
Mathew
,
J.
,
Rajendrakumar
,
P. K.
, and
Karade
,
S.
,
2010
, “
Experimental Studies Using Response Surface Methodology for Condition Monitoring of Ball Bearings
,”
ASME J. Tribol.
,
132
(
4
), p.
044505
.
22.
Boryta
,
D. A.
,
Maas
,
J. A.
, and
Grant
,
C. B.
,
1975
, “
Vapor Pressure-Temperature-Concentration Relationship for the System Lithium Bromide and Water (40-70% Lithium Bromide)
,”
J. Chem. Eng. Data
,
20
(
3
), pp.
316
319
.
23.
Peters
,
R.
, and
Keller
,
J. U.
,
1994
, “
Solvation Model for VLE in the System H,O-LiBr From 5 to 76 wt%
,”
Fluid Phase Equilib.
,
94
(
1
), pp.
129
147
.
24.
Haghtalab
,
A.
, and
Mazloumi
,
S. H.
,
2009
, “
A Nonelectrolyte Local Composition Model and Its Application in the Correlation of the Mean Activity Coefficient of Aqueous Electrolyte Solutions
,”
Fluid Phase Equilib.
,
275
(
1
), pp.
70
77
.
25.
Prausnitz
,
J. M.
,
Lichtenthaler
,
R. N.
, and
Azevedo
,
E. G.
,
1999
,
Molecular Thermodynamics of Fluid-Phase Equilibria
,
3rd ed.
,
Prentice-Hall
,
Upper Saddle River, NJ
.
26.
Chen
,
C. C.
, and
Evans
,
L. B.
,
1986
, “
A Local Composition Model for the Excess Gibbs Energy of Aqueous Electrolyte Systems
,”
AIChE J.
,
32
(
3
), pp.
444
454
.
27.
Zhao
,
E.
,
Yu
,
M.
,
Sauve
,
R. E.
, and
Khoshkbarchi
,
M. K.
,
2000
, “
Extension of the Wilson Model to Electrolyte Solutions
,”
Fluid Phase Equilib.
,
173
(
2
), pp.
161
175
.
28.
Sadeghi
,
R.
,
2005
, “
New Local Composition Model for Electrolyte Solutions
,”
Fluid Phase Equilib.
,
231
(1), pp.
53
60
.
29.
Pitzer
,
K. S.
,
1980
, “
Electrolytes. From Dilute Solutions to Fused Salts
,”
J. Am. Chem. Soc.
,
102
(
9
), pp.
2902
2906
.
30.
Chen
,
C. C.
,
Britt
,
H. I.
,
Boston
,
J. F.
, and
Evans
,
L. B.
,
1982
, “
Local Composition Model for Excess Gibbs Energy of Electrolyte Systems. Part I: Single Solvent, Single Completely Dissociated Electrolyte Systems
,”
AIChE J.
,
28
(
4
), pp.
588
596
.
31.
Montgomery
,
D. C.
,
2001
,
Design and Analysis of Experiments
,
Wiley
,
New York
.
32.
Ray
,
S.
, and
Lalman
,
J. A.
,
2011
, “
Using the Box–Benkhen Design (BBD) to Minimize the Diameter of Electrospun Titanium Dioxide Nanofibers
,”
Chem. Eng. J.
,
169
(1--3), pp.
116
125
.
33.
Khayet
,
M.
,
Cojocaru
,
C.
, and
Trznadel
,
G. Z.
,
2008
, “
Response Surface Modelling and Optimization in Pervaporation
,”
J. Membr. Sci.
,
321
(
2
), pp.
272
283
.
34.
Ferreiraa
,
S. L. C.
,
Brunsb
,
R. E.
,
Ferreiraa
,
H. S.
,
Matosa
,
G. D.
,
Davida
,
J. M.
,
Brandãoa
,
G. C.
,
da Silvaa
,
E. G. P.
,
Portugala
,
L. A.
,
dos Reisc
,
P. S.
,
Souzaa
,
A. S.
, and
dos Santosc
,
W. N. L.
,
2007
, “
Box-Behnken Design: An Alternative for the Optimization of Analytical Methods
,”
Anal. Chim. Acta
,
597
(
2
), pp.
179
186
.
35.
Parsons
,
R. A.
,
1997
,
ASHRAE Handbook of Fundamentals
,
American Society of Heating, Refrigeration and Air Conditioning Engineers
,
Atlanta, GA
.
36.
Lazarev
,
M. A.
, and
Sorochenko
,
V. R.
,
1996
,
Properties of Aqueous Solution of Electrolytes
,
CRC Press
,
London
.
37.
Amani
,
T.
,
Nosrati
,
M.
,
Mousavi
,
S. M.
, and
Kermanshahi
,
R. K.
,
2011
, “
Study of Syntrophic Anaerobic Digestion of Volatile Fatty Acids Using Enriched Cultures at Mesophilic Conditions
,”
Int. J. Environ. Sci. Technol.
,
8
(
1
), pp.
83
96
.
38.
Myers
,
R. H.
, and
Montgomery
,
D. C.
,
1995
,
Response Surface Methodology: Process and Product Optimization Using Designed Experiments
,
Wiley
,
New York
, Chap. 7.
You do not currently have access to this content.