Abstract
Presented are results of experimental investigation of heat transfer at downflow condensation of refrigerant R-21 in a vertical assemblage of minichannels in a plate-fin heat exchanger with plane fins. Selection of refrigerant was caused by the fact that its physical properties at room temperature are similar to those of cryogenic liquids at low temperatures. A pattern of vapor-liquid downflow in the heat exchanger channels was plotted using the working section with a transparent wall. For the mass velocity in the range of 30 to 50 kg/m2s and the wall subcooling below −2◦C, the dependence of the heat transfer coefficient on the mass vapor content is determined and a method is proposed to calculate the heat transfer coefficient that is in good agreement with the experimental data.
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Watel, B., Review of Saturated Flow Boiling in Small Passages of Compact Heat-Exchangers, Int. J. Therm. Sci., 2003, vol. 42, pp. 107–140.
Kuznetsov, V.V. and Shamirzaev, A.S., Experimental Study of Heat Transfer of Dielectric Liquid Perfluorohexane at Flowboiling in a Microchannel Heat Exchanger, J. Eng. Therm., 2017, vol. 26, pp. 146–153.
Gopin, S.R., Usyukin, I.P., and Averyanov, I.G., Heat Transfer in Condensation of Freons on FinnedSurfaces, Heat Transfer-Sov. Res., 1976, vol. 8, no. 6, pp. 103–110.
Clarke, R.H., The Condensation Heat Transfer Characteristics of Liquid Nitrogen in Serrated Plate-Fin Passages, IChemE Symp. Ser., 1994, no. 129, pap.96.
Chen, S.L., Gerver, F.M., and Tien, C.L., General Film Condensation Correlation, Exp. Heat Transfer, 1987, vol. 1, no. 2, pp. 93–107.
Robertson, J.M., Blundell, N., and Clarke R.H., The Condensing Characteristics of Nitrogen in Plain Brazed Aluminum Plate-Fin Heat Exchanger Passages, Heat Transfer 1986, Proc. 8th Int. Heat Transfer Conf., 1986, vol. 4, pp. 1719–1724.
Robertson, J.M., Blundell, N., and Clarke R.H., Characteristics of Pressure Gradients in Downflow Condensing of Nitrogen in Plain Brazed Aluminum Plate-Fin Heat Exchanger Passages, AlChE Symposium Series 83, 1987, vol. 257, pp. 120–125.
Kuznetsov, V.V., Dimov, S.V., Houghton, P.A., Shamirzaev, A.S., and Sunder, S., Upflow Boiling and Condensation in Rectangular Minichannels, ASME 2003 1st Int. Conference on Microchannels and Minichannels, 2003, pp. 683–689.
Kuznetsov, V.V. and Shamirzaev, A.S., Comparative Analysis of Boiling and Condensation Heat Transfer in Upflow for Freon R-21 inMinichannels, J. Eng. Therm., 2015, vol. 24, pp. 357–361.
Pavlenko, A.N., Pecherkin, N.I., and Chekhovich, V.Yu., The Two-Phase Cocurrent Downflow of Liquid Nitrogen in a Vertical Rectangular Channel, Russ. J. Eng. Therm., 2002, vol. 11, no. 4, pp. 321–333.
Chinnov, E.A., Ron’shin F.V., and Kabov, O.A., Two-Phase Flow Patterns in Short Horizontal Rectangular Microchannels, Int. J. Multiphas. Flow, 2016, vol. 80, pp. 57–68.
Cavallini, A., Del Col, D., Doretti, L., Matkovic, M., Rossetto, L., and Zilio, C., Condensation Heat Transfer and Pressure Gradient Inside MultiportMinichannels, Heat Transfer Eng., 2005, vol. 26, no. 3, pp. 45–55.
Kim, S.M, Mudawar, I., Universal Approach to Predicting Heat Transfer Coefficient for Condensing Mini/Micro-Channel Flow, Int. J. HeatMass Transfer, 2013, vol. 56, pp. 238–250.
Rahman, M.M., Kariya, K., and Miyara, A., An Experimental Study and Development of New Correlation for Condensation Heat Transfer Coefficient of Refrigerant Inside aMultiportMinichannel with and without Fins, Int. J. HeatMass Transfer, 2018, vol. 116, pp. 50–60.
Butterworth, D., An Analysis of Film Flow and Its Application to Condensation in a Horizontal Tube, Int. J. Multiphas. Flow, 1974, vol. 1, pp. 671–682.
Asali, J.C, Hanratty, T.J., and Andreussi, P., Interfacial Drag and Film Height for Vertical Annular Flow, AlChE J., 1985, vol. 31, pp. 895–902.
Kuznetsov, V.V. and Shamirzaev A.S., Flow Boiling Heat Transfer of Refrigerant R-134a in Copper Microchannel Heat Sink, Heat Transfer Eng., 2016, vol. 37, pp. 1105–1113
Kuznetsov, V.V. and Safonov, S.A., Fluid Flow and Heat Transfer with Phase Change in Minichannels and Microchannels, Heat Pipes and Solid Sorption Transformations: Fundamentals and Practical Applications, Vasiliev, L.L. and Kakac, S., Eds., Boca Raton: CRC Press, 2013, pp. 465–496.
Liu, Z. and Winterton, R.H.S., A General Correlation for Saturated and Subcooled Flow Boiling in Tubes and Annuli, Based on a Nucleate Pool Boiling Equation, Int. J. Heat Mass Transfer, 1991, vol. 34, pp. 2759–2766.
Shah, R.K. and London, A.L., Laminar Flow Forced Convection in Ducts, Advances in Heat Transfer, Suppl. 1, New York: Academic Press, 1978.
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Kuznetsov, V.V., Dimov, S.V. & Shamirzaev, A.S. Experimental Investigation of Heat Transfer at Downflow Condensation of Refrigerant R-21 in Assemblage of Minichannels. J. Engin. Thermophys. 27, 515–521 (2018). https://doi.org/10.1134/S1810232818040136
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DOI: https://doi.org/10.1134/S1810232818040136