Flow boiling heat transfer

The detail experimental study of flow boiling heat transfer in two-phase heat sinks was performed by Qu and Mudawar (2003b). It was shown that the saturated flow boiling heat transfer coefficient in a micro-channel heat sink is a strong function of mass velocity and depends only weakly on the heat flux. This result, as well as the results by Lee and Lee (2001b), indicates that the dominant mechanism for water micro-channel heat sinks is forced convective boiling but not nucleate boiling. 

Prodanovic V, Fraser D, Salcudean M (2002) On transition from partial to fuUy developed subcooled flow boiling. Int J Heat Mass Transfer 45 4727-4738 Qu W, Mudawar I (2003a) Measurement and prediction of pressure drop in two-phase micro-channel heat sinks. Int J Heat Mass Transfer 46 2737-2753 Qu W, Mudawar I (2003b) Flow boiling heat transfer in two-phase micro-channel heat sink. 1 Experimental investigation and assessment of correlation methods. Int J Heat Mass Transfer 46 2755-2771... 

Peng, C. F., Wang, B. X., Forced convection and flow boiling heat transfer for liquid flowing through microchannels, Int. J. Heat Mass Transfer 36 (1993) 3421-3427. 

Kandlikar, S. G., 1983, An Improved Correlation for Predicting Two-Phase Flow Boiling Heat Transfer Coefficient in Horizontal and Vertical T ubes, ASME HTD Heat Exchangers for Two-Phase Flow Applications, 21st Natl. Heat Transfer Conf., Seattle, WA. (4)... 

D. Steiner and J. Taborek. Flow boiling heat transfer in vertical mbes correlated by an asymptotic model . Heat Transfer Engineering, 13, 2, pp. 43-69 (1992). 

Typical flow pattern for flow boiling are shown in Fig. 5. For subcooled boiling and high liquid flow rate, the observed bubble detachment size is smaller than the gap size. The treatment of the data showed that correlation [26] obtained for a large tube flow boiling can be applied to predict subcooled flow boiling heat transfer in a confined space. For saturated flow, the vapor bubbles have a tendency to merge and produce the... 

Flow Boiling Heat Transfer in Rectangular Channel... 

FLOW BOILING HEAT TRANSFER IN A PASSAGE OF RECTANGULAR CHANNELS... 

Mertz, R., Wein, A., Groll, (1996), Experimental investigation of flow boiling heat transfer in narrow channels, Calore Technologia 14, 2, pp. 47-54. 

Kuznetsov, V.V., Shamirzaev, A.S., (2003), Flow boiling heat transfer in minichannels, Proc. of Eurotherm Seminar No 72 Thermodynamics Heat and Mass Transfer of Refrigeration Machines and Heat Pumps, Valencia, Spain, on March 31 to April 2. 

Kuznetsov, V.V., Shamirzaev, A.S., Ershov I.N., (2004), Flow Boiling Heat Transfer and Regimes of Upward How in Minichannels, 3 Int. Symposium on Two-Phase Flow Modeling and Experimentation, 22-25 September, Pisa, Italy, ven 03. 

ROLE OF MICROSCALE HEAT TRANSFER IN UNDERSTANDING FLOW BOILING HEAT TRANSFER AND ITS ENHANCEMENT... 

In this paper we attempt to review some of the reeent studies on microscale heat transfer involving vapour and liquid two-phase flow covering both experimental and analytical aspects. Furthermore we link these studies to interpreting and understanding boiling heat transfer, and in partieular augmentation of flow boiling heat transfer. 

Enhancement of nucleate boiling heat transfer in large diameter ehannels is often used to augment flow boiling heat transfer. Enhancement teehniques can be elassified either as passive (without external power) or as active (with external power or external additives). Table 1 gives a short list of the various techniques used in the area of boiling heat transfer. From proeess industry perspective the passive techniques are more important than active techniques because of the benefit of simplicity. 

Figure 3. Flow boiling heat transfer in a 25.4 mm i.d. tube at different heat fluxes...

Similar to the large diameter channels, channels with relatively small diameters, of about few millimetres also exhibit some anomalous trends. This is illustrated in Figure 4, where some typical data reported by Huo et al [6], are shown. It can be seen that at high heat fluxes the flow boiling heat transfer coefficient decreases with increasing vapour quality. At the high vapour quality, where the coefficient is independent of heat flux, the mechanism of heat transfer is likely to be two-phase... 

Role of Microscale Heat Transfer in Understanding Flow Boiling Heat Transfer and Its Enhancement 429... 

In several lectures discuss the measurements of single-phase pressure drop and heat transfer coefficient in micro and mini-channels. Experimental results of pressure drop and heat transfer coefficient of flow boiling are presented in mini-channels. Many correlations for flow boiling heat transfer coefficient in mini-channels have been established. 

The nature of boiling heat transfer in a channel with the gap less than the capillary is also studied and presented. The condensation flow mechanisms, pressure drop and heat transfer in microchannels, role of microscale heat transfer in augmentation of nucleate boiling and flow boiling heat transfer, binary-fluid heat and mass transfers in microchannel geometries for miniaturized thermally activated absorption heat pumps, evaporation heat... 

Among the first studies on flow boiling heat transfer in a single channel was the one by Lazarek and Black [1] who reported experimental heat transfer eoeffieients for flow boiling of R-113 in a vertical tube with an inner diameter of 3.1 mm (Fig. 2). Their heat transfer coefficients had a strong dependeney on the applied heat flux, but were essentially independent of vapor quality. Similar results were obtained by Tran et al. [13] and Bao et al. 

Similar results have also been recently reported in flow boiling heat transfer experiments on multi-micro-channel systems, as in the case of Agostini et al. [20, 21] who tested refrigerants R-134a and R-236fa in a 67 parallel micro-channel evaporator (rectangular channels, 0.223 mm wide,... 

Agostini, B., and Thome, J. R., Comparison of an Extended Database for Flow Boiling heat transfer Coefficients in Mnlti-Microchatmel Elements with the Three-Zone Model, ECI Heat Transfer and Fluid Flow in Microscale, Sept. 

Consolini, L., and Thome J. R., Micro-Channel Flow Boiling Heat Transfer of R-134a, R-236fa, and R-245fa, J. Microfluidics and Nanofluidics, doi 10.1007/ s 10404-008-0348-7 (2008). 

Lihong, W., Min, C., and Groll, M., Experimental Study of Flow Boiling Heat Transfer in Mini-Tube, ICMM2005, 2005. 

Zhang, W., Hibiki, T., and Mishima, K., Correlation for Flow Boiling Heat Transfer in Mini-Channels, Int. J. Heat and Mass Transfer, 47, 5749-5763 (2004). 

M. A. Kedzierski, Simultaneous Visual and Calorimetric Measurements of R-ll, R-123, and R-123/ Alkybenzene Nucleate Flow Boiling, Heat Transfer with Alternate Refrigerant, HTD vol. 243, pp. 27-33, ASME, New York, 1993. 

V. V. Yagov, The Principle Mechanisms for Boiling Contribution in Flow Boiling Heat Transfer, in Convective Flow Boiling, J. C. Chen ed., pp. 175-180, Taylor Francis, Washington, DC, 1996. 

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