In the present study, the ammonia-water mixing flow in a bubble pump is numerically simulated. The flow patterns of a two-phase flow in a bubble pump were studied under different conditions of heat flux and tube diameter. A one-dimensional two-fluid model was developed under constant heat flux. This model was used to predict the variations in void fraction and liquid and vapor velocities throughout the tube. Then, the void fraction profile and the curve of liquid velocity versus vapor velocity were used to predict the flow patterns along the tube length. It was found that at heat fluxes below 15kWm2, bubbly, slug, and churn flows are the dominating regimes, and the length of these flow regimes depends on the tube diameter. For heat fluxes higher than 15kWm2, the bubble pump operates under the churn and annular regimes, and the bubble pump performance is improved when the tube diameter increases.

1.
Benhmidene
,
A.
,
Chaouachi
,
B.
, and
Gabsi
,
B.
, 2010, “
A Review of Bubble Pump Technologies
,”
J. Appl. Sci.
1812-5654,
10
, pp.
1806
1813
.
2.
Nicklin
,
D. J.
, 1963, “
The Air-Lift Pump: Theory and Optimization
,”
Trans. Inst. Chem. Eng.
0371-7496,
41
, pp.
29
38
.
3.
Lister
,
G. D. S.
, 1996, “
The Design and Evaluation of a Pumping System for a Three Fluid Absorption Refrigeration Plant
,” BS thesis, University of Cape Town, Cape Town, South Africa.
4.
Pfaff
,
M.
,
Saravanan
,
R.
,
Maiya
,
M. P.
, and
Srinivasa
,
M.
, 1998, “
Studies on Bubble Pump for a Water–Lithium Bromide Vapor Absorption Refrigeration
,”
Int. J. Refrig.
0140-7007,
21
, pp.
452
462
.
5.
Jeong
,
S.
,
Lee
,
S. K.
, and
Koo
,
K. K.
, 1998, “
Pumping Characteristics of a Thermosyphon Applied for Absorption Refrigerators With Working Pair of Li/Br
,”
Appl. Therm. Eng.
1359-4311,
18
, pp.
1309
1323
.
6.
Delano
,
A. D.
, 1998, “
Design Analysis of the Einstein Refrigeration Cycle
,” Ph.D. thesis, Georgia Institute of Technology, Atlanta, GA.
7.
White
,
S. J.
, 2001, “
Bubbles Pump Design and Performance
,” MS thesis, Georgia Institute of Technology, Atlanta, GA.
8.
Koyfman
,
A.
,
Jelinek
,
M.
,
Levy
,
A.
, and
Borde
,
I.
, 2003, “
An Experimental Investigation of Bubble Pump Performance for Diffusion Absorption Refrigeration System With Organic Working Fluids
,”
Appl. Therm. Eng.
1359-4311,
23
, pp.
1881
1894
.
9.
Chisholm
,
D.
, 1983,
Two-Phase Flow in Pipelines and Heat Exchangers
,
Longman
,
New York
.
10.
Vicatos
,
G.
, and
Bennett
,
A.
, 2007, “
Multiple Lift Tube Pumps Boost Refrigeration Capacity in Absorption Plants
,”
J. Energ. South Af.
,
18
, pp.
49
57
.
11.
Hewitt
,
G. F.
, and
Wallis
,
G. B.
, 1963, “
Flooding and Associated Phenomena in Falling Film Flow in a Vertical Tube
,”
UKAEA
, Report No. AERE-R4022.
12.
Radovich
,
N. A.
, and
Moissis
,
R.
, 1962, “
The Transition From Two-Phase Bubble Flow to Slug Flow
,”
MIT
, Report No. 7-7673-22.
13.
Taitel
,
Y.
,
Bornea
,
D.
, and
Dukler
,
A. E.
, 1980, “
Modelling Flow Pattern Transitions for Steady Upward Gas-Liquid Flow in Vertical Tubes
,”
AIChE J.
0001-1541,
26
, pp.
345
354
.
14.
Mishima
,
K.
, and
Ishii
,
M.
, 1984, “
Flow Regime Transition Criteria for Upward Two-Phase Flow in Vertical Tubes
,”
Int. J. Heat Mass Transfer
0017-9310,
27
, pp.
723
737
.
15.
Xu
,
J. L.
,
Cheng
,
P.
, and
Zhao
,
T. S.
, 1999, “
Gas-Liquid Two-Phase Flow Regimes in Rectangular Channels With Mini/Micro Gaps
,”
Int. J. Multiphase Flow
0301-9322,
25
, pp.
411
432
.
16.
Brauner
,
N.
, and
Barnea
,
D.
, 1986, “
Slug/Churn Transition in Upward Gas-Liquid Flow
,”
Chem. Eng. Sci.
0009-2509,
41
, pp.
159
163
.
17.
Wallis
,
G. B.
, 1969,
One-Dimensional Two-Phase Flow
,
McGraw-Hill
,
New York
.
18.
Barnea
,
D. A.
, 1987, “
Unified Model for Predicting Flow Pattern Transitions for the Whole Range of Pipe Inclinations
,”
Int. J. Multiphase Flow
0301-9322,
13
, pp.
1
12
.
19.
Haberstroh
,
R. E.
, and
Griffith
P.
, 1965, “
Slug-Annular Two-Phase Flow Regime Transition
,” ASME Paper No. 65-HT-52.
20.
Beattie
,
D. R. H.
, and
Whalley
,
P. B.
, 1982, “
A Simple Two-Phase Frictional Pressure Drop Calculation Method
,”
Int. J. Multiphase Flow
0301-9322,
8
, pp.
83
87
.
21.
Zuber
,
N.
, and
Findlay
,
J.
, 1965, “
Average Volumetric Concentration in Two-Phase Flow Systems
,”
ASME J. Heat Transfer
0022-1481,
87
, pp.
453
468
.
22.
Levy
,
A.
,
Koyfman
,
A.
, and
Jelinek
,
M.
, 2006, “
Flow Boiling of Organic Binary Mixtures
,”
Int. J. Multiphase Flow
0301-9322,
32
, pp.
1300
1310
.
23.
Yang
,
L.
, and
Zhang
,
C. L.
, 2005, “
Two-Fluid Model of Refrigerant Two-Phase Flow Through Short Tube Orifice
,”
Int. J. Refrig.
0140-7007,
28
, pp.
419
427
.
24.
Seixlack
,
A. L.
, and
Barbazelli
,
M. R.
, 2009, “
Numerical Analysis of Refrigerant Flow Along Non-Adiabatic Capillary Tubes Using a Two-Fluid Model
,”
Appl. Therm. Eng.
1359-4311,
29
, pp.
523
531
.
25.
Ishii
,
M.
, and
Mishima
,
K.
, 1984, “
Two-Fluid Model and Hydrodynamic Constitutive Relations
,”
Nucl. Eng. Des.
0029-5493,
82
, pp.
107
126
.
26.
Richter
,
H. J.
, 1983, “
Separated Two-Phase Flow Model: Application to Critical Two Phase Flow
,”
Int. J. Multiphase Flow
0301-9322,
9
, pp.
511
530
.
27.
Xu
,
J. L.
,
Wong
,
T. N.
, and
Huang
,
X. Y.
, 2006, “
Two-Fluid Modeling for Low-Pressure Subcooled Flow Boiling
,”
Int. J. Heat Mass Transfer
0017-9310,
49
, pp.
377
386
.
28.
Chisholm
,
D.
, 1973, “
Pressure Gradient Due to Friction During the Flow of Evaporating Two Phase Mixtures in Smooth Tubes and Channel
,”
Int. J. Heat Mass Transfer
0017-9310,
16
, pp.
347
358
.
29.
Baroczy
,
C. J.
, 1965, “
A Systematic Correlation for Two-Phase Pressure Drop
,”
Chem. Eng. Prog., Symp. Ser.
0069-2948,
62
, pp.
232
249
.
30.
Hainoun
,
A.
,
Hicken
,
E.
, and
Wolters
,
J.
, 1996, “
Modeling of Void Formation in the Subcooled Boiling Regime in the ATHLET Code to Simulate Flow Instability for Research Reactors
,”
Nucl. Eng. Des.
0029-5493,
16
, pp.
7175
7191
.
31.
Chen
,
J. C.
, 1966, “
Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow
,”
Ind. Eng. Chem. Process Des. Dev.
0196-4305,
5
, pp.
322
329
.
32.
Celata
,
G. P.
,
Cumo
,
M.
, and
Setaro
,
T.
, 1993, “
Forced Convective Boiling in Binary Mixtures
,”
Int. J. Heat Mass Transfer
0017-9310,
36
, pp.
3299
3309
.
33.
Bourseau
,
P.
, and
Bugarel
,
R.
, 1986, “
Absorption-Diffusion Machines: Comparison of the Performances of NH3–H2O and NH3–NaSCN
,”
Int. J. Refrig.
0140-7007,
9
, pp.
206
214
.
34.
Tillner-Roth
,
R.
, and
Friend
,
D. G.
, 1998, “
Survey and Assessment of Available Measurements on Thermodynamic Properties of the Mixture {Water+Ammonia}
,”
J. Phys. Chem. Ref. Data
0047-2689,
27
, pp.
45
61
.
35.
Pátek
,
J.
, and
Klomfar
,
J.
, 1995, “
Simple Functions for Fast Calculations of Selected Thermodynamic Properties of Ammonia–Water system
,”
Int. J. Refrig.
0140-7007,
18
, pp.
228
234
.
36.
Rouhani
,
Z.
, and
Axelsson
,
E.
, 1970, “
Calculation of Volume Void Fraction in the Subcooled and Quality Region
,”
Int. J. Heat Mass Transfer
0017-9310,
13
, pp.
383
393
.
37.
Zivi
,
S. M.
, 1964, “
Estimation of Steady State Steam Void Fraction by Means of Principle of Minimum Entropy Production
,”
ASME Trans. J. Heat Transfer
0022-1481,
86
, pp.
247
252
.
38.
Dukler
,
A. E.
, and
Taitel
,
Y.
, 1986, “
Flow Pattern Transitions in Gas-Liquid Systems: Measurement and Modeling
,”
Multiphase Science and Technology 2
,
Hemisphere
,
Washington, DC
.
39.
Mao
,
Z. S.
, and
Dukler
,
A. E.
, 1993, “
The Myth of Chum Flow
,”
Int. J. Multiphase Flow
0301-9322,
19
, pp.
377
383
.
40.
McQuillan
,
K. W.
, and
Whalley
,
P. B.
, 1985, “
Flow Patterns in Vertical Two-Phase Flow
,”
Int. J. Multiphase Flow
0301-9322,
11
, pp.
161
175
.
41.
Jayanti
,
S.
, and
Hewitt
,
G. F.
, 1992, “
Prediction of the Slug-To-Churn Flow Transition in Vertical Two-Phase Flow
,”
Int. J. Multiphase Flow
0301-9322,
18
, pp.
847
860
.
You do not currently have access to this content.