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Research Papers: Heat Exchangers

The New Mathematical Models for Plain Fin-and-Tube Heat Exchangers With Dehumidification

[+] Author and Article Information
Worachest Pirompugd

Department of Mechanical Engineering,
Faculty of Engineering,
Burapha University,
Saensook, Muang,
Chonburi 20131, Thailand
e-mail: worapiro@gmail.com

Chi-Chuan Wang

Department of Mechanical Engineering,
National Chiao Tung University,
EE474, 1001 University Road,
Hsinchu 300, Taiwan
e-mail: ccwang@mail.nctu.edu.tw

Somchai Wongwises

Fluid Mechanics,
Thermal Engineering and Multiphase
Flow Research Laboratory (FUTURE),
Department of Mechanical Engineering,
Faculty of Engineering,
King Mongkut's
University of Technology Thonburi,
Bangmod, Bangkok 10140, Thailand
e-mail: somchai.won@kmutt.ac.th

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received May 29, 2014; final manuscript received October 24, 2014; published online December 2, 2014. Assoc. Editor: Ali Khounsary.

J. Heat Transfer 137(3), 031801 (Mar 01, 2015) (11 pages) Paper No: HT-14-1357; doi: 10.1115/1.4029037 History: Received May 29, 2014; Revised October 24, 2014; Online December 02, 2014

For evaluating performance of fin-and-tube heat exchangers under dehumidifying conditions, the recent lumped approach models are based on the enthalpy potential or equivalent dry bulb temperature. This study proposes a new lumped approach model based on the dry bulb temperature difference. The concept of dry bulb temperature was first presented by McQuiston for derivation of fin efficiency under dehumidifying conditions in 1975. This concept is simpler than the concepts of enthalpy potential and equivalent dry bulb temperature. Nevertheless, it cannot be found that this concept is applied to the fin-and-tube heat exchangers. Moreover, this study also presents the finite circular fin method (FCFM) based on the dry bulb temperature and equivalent dry bulb temperature. The FCFM was first presented in our published literature but it was based on the enthalpy potential. The FCFM is done by dividing the fin-and-tube heat exchanger into many small segments. Then, the segments are divided into three cases: fully dry condition, fully wet condition, and partially wet condition. From the results, the new lumped approach model based on dry bulb temperature gives a good result. It is the simplest method for evaluating heat transfer performance of fin-and-tube heat exchangers under fully wet conditions. For the FCFM, the heat and mass transfer characteristics obtained by dry bulb temperature and equivalent dry bulb temperature are nearly the same as those obtained by the enthalpy potential. However, the heat and mass transfer characteristics by the FCFM based on equivalent dry bulb temperature are higher than those obtained by the FCFM based on dry bulb temperature. This is because of the effect of the nonconstant term in the two methods. The correlations applicable for both fully wet and partially wet conditions for the FCFMs based on equivalent dry bulb temperature and dry bulb temperature are proposed to describe the heat and mass transfer characteristics for the present plain fin configuration.

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References

Threlkeld, J. L., 1970, Thermal Environmental Engineering, Prentice-Hall, New York.
Jacobi, A. M., and Goldschmidt, V. W., 1990, “Low Reynolds Number Heat and Mass Transfer Measurements of an Overall Counter-Flow Baffled Finned-Tube Condensing Heat Exchanger,” ASME J. Heat Transfer, 33(4), pp. 755–765. [CrossRef]
Wang, C. C., Hsieh, Y. C., and Lin, Y. T., 1997, “Performance of Plate Finned Tube Heat Exchangers Under Dehumidifying Conditions,” ASME J. Heat Transfer, 119(1), pp. 109–117. [CrossRef]
Corberan, J. M., and Melon, M. G., 1998, “Modeling of Plate Finned Tube Evaporators and Condensers Working With R134a,” Int. J. Refrig., 21(4), pp. 273–284. [CrossRef]
Wang, C. C., Lin, Y. T., and Lee, C. J., 2000, “An Airside Correlation for Plain Fin-and-Tube Heat Exchangers in Wet Conditions,” Int. J. Heat Mass Transfer, 43(10), pp. 1869–1872. [CrossRef]
Wang, C. C., Lin, Y. T., and Lee, C. J., 2000, “Heat and Momentum Transfer for Compact Louvered Fin-and-Tube Heat Exchangers in Wet Conditions,” Int. J. Heat Mass Transfer, 43(18), pp. 3443–3452. [CrossRef]
Kim, M. H., and Bullard, C. W., 2002, “Air-Side Performance of Brazed Aluminum Heat Exchangers Under Dehumidifying Conditions,” Int. J. Refrig., 25(7), pp. 924–934. [CrossRef]
Wang, C. C., Lee, W. S., Sheu, W. J., and Chang, Y. J., 2002, “A Comparison of the Airside Performance of the Fin-and-Tube Heat Exchangers in Wet Conditions; With and Without Hydrophilic Coating,” Appl. Therm. Eng., 22(3), pp. 267–278. [CrossRef]
Liu, Y. C., Wongwises, S., Chang, W. J., and Wang, C. C., 2010, “Airside Performance of Fin-and-Tube Heat Exchangers in Dehumidifying Conditions—Data With Larger Diameter,” Int. J. Heat Mass Transfer, 53(7–8), pp. 1603–1608. [CrossRef]
Phan, T. L., Chang, K. S., Kwon, Y. C., and Kwon, J. T., 2011, “Experimental Study on Heat and Mass Transfer Characteristics of Louvered Fin-Tube Heat Exchangers Under Wet Condition,” Int. Commun. Heat Mass Transfer, 38(7), pp. 893–899. [CrossRef]
Wang, C. C., and Liaw, J. S., 2012, “Air-Side Performance of Herringbone Wavy Fin-and-Tube Heat Exchangers Under Dehumidifying Condition–Data With Larger Diameter Tube,” Int. J. Heat Mass Transfer, 55(11–12), pp. 3054–3060. [CrossRef]
Pongsoi, P., Pikulkajorn, S., and Wongwises, S., 2012, “Effect of Fin Pitches on the Optimum Heat Transfer Performance of Crimped Spiral Fin-and-Tube Heat Exchangers,” Int. J. Heat Mass Transfer, 55(23–24), pp. 6555–6566. [CrossRef]
Pongsoi, P., Pikulkajorn, S., Wang, C. C., and Wongwises, S., 2012, “Effect of Number of Tube Rows on the Air-Side Performance of Crimped Spiral Fin-and-Tube Heat Exchanger With a Multipass Parallel and Counter Cross-Flow Configuration,” Int. J. Heat Mass Transfer, 55(4), pp. 1403–1411. [CrossRef]
Pirompugd, W., Wongwises, S., and Wang, C. C., 2005, “A Tube-by-Tube Reduction Method for Simultaneous Heat and Mass Transfer Characteristics for Plain Fin-and-Tube Heat Exchangers in Dehumidifying Conditions,” Heat Mass Transfer, 41(8), pp. 756–765. [CrossRef]
Pirompugd, W., Wongwises, S., and Wang, C. C., 2006, “Simultaneous Heat and Mass Transfer Characteristics for Wavy Fin-and-Tube Heat Exchangers Under Dehumidifying Conditions,” Int. J. Heat Mass Transfer, 49(1–2), pp. 132–143. [CrossRef]
Pirompugd, W., Wang, C. C., and Wongwises, S., 2007, “A Fully Wet and Fully Dry Tiny Circular Fin Method for Heat and Mass Transfer Characteristics for Plain Fin-and-Tube Heat Exchangers Under Dehumidifying Conditions,” ASME J. Heat Transfer, 129(9), pp. 1256–1267. [CrossRef]
Pirompugd, W., Wang, C. C., and Wongwises, S., 2007, “Heat and Mass Transfer Characteristics for Finned Tube Heat Exchangers With Humidification,” J. Thermophys. Heat Transfer, 21(2), pp. 361–371. [CrossRef]
Pirompugd, W., Wang, C. C., and Wongwises, S., 2007, “Finite Circular Fin Method for Heat and Mass Transfer Characteristics for Plain Fin-and-Tube Heat Exchangers Under Fully and Partially Wet Surface Conditions,” Int. J. Heat Mass Transfer, 50(3–4), pp. 552–565. [CrossRef]
Pirompugd, W., Wang, C. C., and Wongwises, S., 2008, “Finite Circular Fin Method for Wavy Fin-and-Tube Heat Exchangers Under Fully and Partially Wet Surface Conditions,” Int. J. Heat Mass Transfer, 51(15–16), pp. 4002–4017. [CrossRef]
Wang, J., and Hihara, E., 2003, “Prediction of Air Coil Performance Under Partially Wet and Totally Wet Cooling Conditions Using Equivalent Dry-Bulb Temperature Method,” Int. J. Refrig., 26(3), pp. 293–301. [CrossRef]
McQuiston, F. C., 1975, “Fin Efficiency With Combined Heat and Mass Transfer,” ASHRAE Trans., 81(1), pp. 350–355.
McQuiston, F. C., and Parker, J. D.,1994, Heating Ventilating and Air Conditioning, 4th ed., Wiley, New York.
Hong, T. K., and Webb, R. L., 1996, “Calculation of Fin Efficiency for Wet and Dry Fins,” Int. J. HVAC R Res., 2(1), pp. 27–41. [CrossRef]
Gnielinski, V., 1976, “New Equation for Heat and Mass Transfer in Turbulent Pipe and Channel Flow,” Int. Chem. Eng., 16(2), pp. 359–368.
Pirompugd, W., and Wongwises, S., 2013, “Efficiencies for Partially Wetted Spine Fins: Uniform Cross Section, Conical, Concave Parabolic, and Convex Parabolic Spines,” ASME J. Heat Transfer, 135(8), p. 081903. [CrossRef]
Pirompugd, W., and Wongwises, S., 2013, “Partially Wet Fin Efficiency for the Longitudinal Fins of Rectangular, Triangular, Concave Parabolic, and Convex Parabolic Profiles,” J. Franklin Inst., 350(6), pp. 1424–1442. [CrossRef]
Pirompugd, W., Wang, C. C., and Wongwises, S., 2009, “A Review on Reduction Method for Heat and Mass Transfer of Fin-and-Tube Heat Exchangers Under Dehumidifying Conditions,” Int. J. Heat Mass Transfer, 52(9–10), pp. 2370–2378. [CrossRef]
Pirompugd, W., Wang, C. C., and Wongwises, S., 2010, “Correlations for Wet Surface Ratio of Fin-and-Tube Heat Exchangers,” Int. J. Heat Mass Transfer, 53(1–3), pp. 568–573. [CrossRef]
Kern, D. Q., and Kraus, A. D., 1972, Extended Surface Heat Transfer, McGraw-Hill, New York.

Figures

Grahic Jump Location
Fig. 1

Comparison of jh between lump approach and FCFM. (a) jh between enthalpy potential and presented dry bulb temperature. (b) jh between lump approach and FCFM.

Grahic Jump Location
Fig. 2

Fin efficiency for a partially wet condition plotted against Mm(ro − ri)

Grahic Jump Location
Fig. 3

di/dT, ζ, and (1 + ξifg/Cp,a) plotted against r for radial fin

Grahic Jump Location
Fig. 4

Comparison of jh and jm between those obtained by FCFM-DT or FCFM-EDT with FCFM-EP (a) jh obtained by FCFM-EDT versus FCFM-EP, (b) jh obtained by FCFM-DT versus FCFM-EP,(c) jm obtained by FCFM-EDT versus FCFM-EP, and (d) jm obtained by FCFM-DT versus FCFM-EP

Grahic Jump Location
Fig. 5

jh obtained by FCFM-EDT and FCFM-DT. (a) jh for 1 Row with RH = 0.5, (b) jh for 2 Rows with RH = 0.5, (c) jh for 4 Rows with RH = 0.5, (d) jh for 6 Rows with RH = 0.5, (e) jh for 4 Rows with RH = 0.9, and (f) jh for 6 Rows with RH = 0.9.

Grahic Jump Location
Fig. 6

jm obtained by FCFM-EDT and FCFM-DT. (a) jm for 1 Row with RH = 0.5, (b) jm for 2 Rows with RH = 0.5, (c) jm for 4 Rows with RH = 0.5, (d) jm for 6 Rows with RH = 0.5, (e) jm for 4 Rows with RH = 0.9, and (f) jm for 2 Rows with RH = 0.9.

Grahic Jump Location
Fig. 7

Comparison of predicted data with experimental data. (a) jh by FCFM-EDT, (b) jm by FCFM-EDT, (c) jh by FCFM-DT, and (d) jm by FCFM-DT.

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