Two-phase pressure drop, boiling heat transfer, and critical heat flux to water in a small-diameter horizontal tube

Flow Boiling in an Asymmetrically Heated Single Rectangular Microchannel

“…The mass flux and vapor quality did not influence the heat transfer coefficients. Other experimental results (Yu et al, 2002) showed a similar trend and the boiling heat transfer correlation to these results. The flow boiling experiments of R-141b in 500-mm-long channels from 1.39 to 3.69 mm in diameter were carried out (Kew & Cornwell, 1997).…”

“…This characteristic of the flow boiling is unique to microchannel, and is not observed in the macro-channels. (Chen, 1966, as cited in Collier & Thome, 1994Shah, 1976, as cited in Collier & Thome, 1994Kandlikar, 1990) and three mini/microchannel correlations (Lazarek & Black, 1982;Yu et al, 2002;Warrier et al, 2002), were examined. As described in the previous section, two kinds of heat transfer mechanisms are superimposed in the flow boiling.…”

“…They proposed a modified C parameter based on the Lockhart-Martinelli two-phase multiplier to take into account the effects of the viscous and surface tension forces. For small channels, the occurrence of slug flow over a large quality range reduced the pressure gradients from those of the annular flow conditions found in larger tubes (Yu et al, 2002). Recently, a modified Mishima and Hibiki correlation by appending the mass flux effect to the Chisholm's C parameter was proposed based on experimental results with 21 parallel channels, 0.231 mm in width and 0.712 mm in height .…”

“…Finally, the elongated bubble behavior in a microchannel was analyzed by comparing experimental observations and numerical calculations. (Mishima & Hibiki, 1996;Mishima et al, 1993;Tran et al, 2000;Yu et al, 2002; Table 2. Summary of previous studies on flow boiling heat transfer in mini/microchannels (Lazarek & Black, 1982;Tran et al, 1996;Kew & Cornwell, 1997;Yan & Lin, 1998;Warrier et al, 2002;Yu et al, 2002; 2.…”

A composite heat transfer correlation for saturated flow boiling in small channels

“…However, even the best predictions showed a mean absolute error (MAE) of 40% against the large experimental database, and predicted less than half of the measured data to within a deviation of ±30%. It was also noted in [1] that most of the existing minichannel and microchannel heat transfer correlations were developed based on small data sets [13][14][15][16][17][18][19][20]. As a result, these correlations usually performed well in the parameter range over which they were fit, but did not extrapolate well beyond their often narrow operating range [1].…”