Visual Study on Flow Patterns and Heat Transfer during Convective Boiling Inside Horizontal Smooth and Microfin Tubes
Evaporator is an important and widely used heat
exchanger in air conditioning and refrigeration industries. Different
methods have been used by investigators to increase the heat transfer
rates in evaporators. One of the passive techniques to enhance heat
transfer coefficient is the application of microfin tubes. The
mechanism of heat transfer augmentation in microfin tubes is
dependent on the flow regime of two-phase flow. Therefore many
investigations of the flow patterns for in-tube evaporation have been
reported in literatures. The gravitational force, surface tension and
the vapor-liquid interfacial shear stress are known as three dominant
factors controlling the vapor and liquid distribution inside the tube. A
review of the existing literature reveals that the previous
investigations were concerned with the two-phase flow pattern for
flow boiling in horizontal tubes [12], [9]. Therefore, the objective of
the present investigation is to obtain information about the two-phase
flow patterns for evaporation of R-134a inside horizontal smooth and
microfin tubes. Also Investigation of heat transfer during flow
boiling of R-134a inside horizontal microfin and smooth tube have
been carried out experimentally The heat transfer coefficients for
annular flow in the smooth tube is shown to agree well with Gungor
and Winterton-s correlation [4]. All the flow patterns occurred in the
test can be divided into three dominant regimes, i.e., stratified-wavy
flow, wavy-annular flow and annular flow. Experimental data are
plotted in two kinds of flow maps, i.e., Weber number for the vapor
versus weber number for the liquid flow map and mass flux versus
vapor quality flow map. The transition from wavy-annular flow to
annular or stratified-wavy flow is identified in the flow maps.
[1] Bergles, AE & Suo, M. Investigation of boiling water flow
regimes at high pressure. In: Proc. Heat Trans. Fluid Mech.
Institute. Stanford Press, p. 77-79 (1966)
[2] Schultz, R.R. & Cole, R. Uncertainty Analysis in Boiling
Nucleation, AIChE Symp. Series, Vol.75, No.189, pp. 32-38,
(1979)
[3] Agrawal, K.N. & Varma, H.K. & Lal, S.N. Heat Transfer
During Forced Convection Boiling of R12 Under Swirl Flow,
ASME J. Heat Transfer, Vol. 108, pp. 567-573, (1986)
[4] Gungor, K.E. & Winterton, R.H. Simplified General Correlation
for Saturated Flow Boiling and Comparison of Correlations to
Data", Industrial & Engineering Chemistry Process Design and
Development, Vol. 65, pp.148-156, (1987)
[5] Carey VP. Liquid-vapor phase-change phenomena. Washington
(DC): Hemisphere Pub. Co, (1992)
[6] Thors, P. & Bogart, J.E. In-Tube Evaporation of HCFC-22 with
Enhanced Tubes, J. Enhanced Heat Transfer, Vol. 1, pp. 365-
377, (1994)
[7] Webb, R.L. Principles of Enhanced Heat Transfer, John Wiley
and Sons, New York (1994)
[8] Chamra, L. & Webb, R. & Randlett, M. Advanced Microfin
Tubes for Evaporation, International Journal of Heat and Mass
Transfer, Vol. 39 (9), pp.1827-1838, (1996)
[9] Kattan, N. & Thome, J.R. & Favrat, D. Flow boiling in
horizontal tubes: Part 1: development of a diabatic two-phase
flow pattern map. Journal of Heat Transfer ;120:140-7.( 1998)
[10] Muzzio, A. & Niro, A. & Garavaglia, M. Flow patterns and heat
transfer coefficients in flow-boiling and convective
condensation of R22 inside a microfin tube of new design, in:
Heat Transfer 1998, Proceedings of 11th IHTC, Kyongju,
Korea, vol. 2, , pp. 291-296 ( 1998)
[11] Stoecker, W.F. Industrial refrigeration handbook, Mc Graw
Hill Companies, Inc. (1998)
[12] Ming-huei, Yu. & Tsun-kuo, Lin & Chyuan-chyi, Tseng Heat
transfer and flow pattern during two-phase flow boiling of R-
134a in horizontal smooth and microfin tubes. International
jornal of refrigeration (2001)
[13] Sonntag, R.E. & Borgnakke, C. & Van Wylen, G.J.
Fundamentals of Thermodynamics, John wiley and sons, New
York, (2003)
[14] Thome, J.R. Engineering Data BookIII, by Wolverin tube, Inc.
(2004-2006)
[1] Bergles, AE & Suo, M. Investigation of boiling water flow
regimes at high pressure. In: Proc. Heat Trans. Fluid Mech.
Institute. Stanford Press, p. 77-79 (1966)
[2] Schultz, R.R. & Cole, R. Uncertainty Analysis in Boiling
Nucleation, AIChE Symp. Series, Vol.75, No.189, pp. 32-38,
(1979)
[3] Agrawal, K.N. & Varma, H.K. & Lal, S.N. Heat Transfer
During Forced Convection Boiling of R12 Under Swirl Flow,
ASME J. Heat Transfer, Vol. 108, pp. 567-573, (1986)
[4] Gungor, K.E. & Winterton, R.H. Simplified General Correlation
for Saturated Flow Boiling and Comparison of Correlations to
Data", Industrial & Engineering Chemistry Process Design and
Development, Vol. 65, pp.148-156, (1987)
[5] Carey VP. Liquid-vapor phase-change phenomena. Washington
(DC): Hemisphere Pub. Co, (1992)
[6] Thors, P. & Bogart, J.E. In-Tube Evaporation of HCFC-22 with
Enhanced Tubes, J. Enhanced Heat Transfer, Vol. 1, pp. 365-
377, (1994)
[7] Webb, R.L. Principles of Enhanced Heat Transfer, John Wiley
and Sons, New York (1994)
[8] Chamra, L. & Webb, R. & Randlett, M. Advanced Microfin
Tubes for Evaporation, International Journal of Heat and Mass
Transfer, Vol. 39 (9), pp.1827-1838, (1996)
[9] Kattan, N. & Thome, J.R. & Favrat, D. Flow boiling in
horizontal tubes: Part 1: development of a diabatic two-phase
flow pattern map. Journal of Heat Transfer ;120:140-7.( 1998)
[10] Muzzio, A. & Niro, A. & Garavaglia, M. Flow patterns and heat
transfer coefficients in flow-boiling and convective
condensation of R22 inside a microfin tube of new design, in:
Heat Transfer 1998, Proceedings of 11th IHTC, Kyongju,
Korea, vol. 2, , pp. 291-296 ( 1998)
[11] Stoecker, W.F. Industrial refrigeration handbook, Mc Graw
Hill Companies, Inc. (1998)
[12] Ming-huei, Yu. & Tsun-kuo, Lin & Chyuan-chyi, Tseng Heat
transfer and flow pattern during two-phase flow boiling of R-
134a in horizontal smooth and microfin tubes. International
jornal of refrigeration (2001)
[13] Sonntag, R.E. & Borgnakke, C. & Van Wylen, G.J.
Fundamentals of Thermodynamics, John wiley and sons, New
York, (2003)
[14] Thome, J.R. Engineering Data BookIII, by Wolverin tube, Inc.
(2004-2006)
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:58358", author = "V.D. Hatamipour and M.A. Akhavan-Behabadi", title = "Visual Study on Flow Patterns and Heat Transfer during Convective Boiling Inside Horizontal Smooth and Microfin Tubes", abstract = "Evaporator is an important and widely used heat
exchanger in air conditioning and refrigeration industries. Different
methods have been used by investigators to increase the heat transfer
rates in evaporators. One of the passive techniques to enhance heat
transfer coefficient is the application of microfin tubes. The
mechanism of heat transfer augmentation in microfin tubes is
dependent on the flow regime of two-phase flow. Therefore many
investigations of the flow patterns for in-tube evaporation have been
reported in literatures. The gravitational force, surface tension and
the vapor-liquid interfacial shear stress are known as three dominant
factors controlling the vapor and liquid distribution inside the tube. A
review of the existing literature reveals that the previous
investigations were concerned with the two-phase flow pattern for
flow boiling in horizontal tubes [12], [9]. Therefore, the objective of
the present investigation is to obtain information about the two-phase
flow patterns for evaporation of R-134a inside horizontal smooth and
microfin tubes. Also Investigation of heat transfer during flow
boiling of R-134a inside horizontal microfin and smooth tube have
been carried out experimentally The heat transfer coefficients for
annular flow in the smooth tube is shown to agree well with Gungor
and Winterton-s correlation [4]. All the flow patterns occurred in the
test can be divided into three dominant regimes, i.e., stratified-wavy
flow, wavy-annular flow and annular flow. Experimental data are
plotted in two kinds of flow maps, i.e., Weber number for the vapor
versus weber number for the liquid flow map and mass flux versus
vapor quality flow map. The transition from wavy-annular flow to
annular or stratified-wavy flow is identified in the flow maps.", keywords = "Flow boiling, Flow pattern, Heat transfer,Horizontal, Smooth tube, Microfin tube.", volume = "4", number = "9", pages = "856-7", }