Yan and Lin [34] investigated experiments on evaporation heat transfer in multi-port circular tube with an inner diameter of 2 mm. They proposed an equation for heat transfer similar to the Kandlikar [2] correlation,
including three non-dimensional numbers: the boiling number, the liquid Froude number, and the convection number (Table 3). Cooper’s correlation [35] that is developed and widely used for nucleate pool boiling heat transfer is recommended by Harirchian et al. [1] to predict flow boiling heat transfer in microchannels. However, Harirchian et al. [1] found that the Cooper’s correlation predicts their experimental results with 27% as mean absolute percentage error. Liu and Witerton eFT508 chemical structure [36] used Cooper’s correlation and introduced an enhancement factor due to the forced convective heat transfer mechanism caused by bubbles generated in the flow. Bertsch et al. [30] developed a generalized correlation for flow boiling heat transfer
in channels with hydraulic diameters ranging from 0.16 to 2.92 mm. The proposed correlation by Bertsch et al. [30] predicts these measurements with a mean absolute error less than 30%. Table 2 Correlations for boiling flow heat transfer coefficient Reference Fluid composition Description click here Correlation Geometry Comment Parameter range Warrier et al. [27] FC-84 Small rectangular parallel channels of D h = 0.75mm Single-phase forced convection and ZD1839 subcooled and saturated nucleate boiling 3 < x <55% Kandlikar and Balasubramanian [28] Water, refrigerants, and cryogenic fluids Minichannels and microchannels Flow boiling x <0.7 ~ 0.8 h sp is calculated Equation 7 Sun and Mishima [29] Water, refrigerants (R11, R12, R123, R134a, R141b, R22, R404a, R407c, R410a) and CO2 Minichannel diameters from 0.21 to 6.05 mm Flow boiling laminar flow region Re L < 2,000 and Re G < 2,000 Bertsch et al. [30] Hydraulic diameters ranging from 0.16 to 2.92 mm Minichannels Flow boiling and vapor quality 0 to 1 h nb is calculated by Cooper [35]: h sp = χ v,x h sp,go + (1 − χ v,x )h sp,lo (13) Temperature −194°C
to 97°C Heat flux 4–1,150 kW/m2 Mass flux 20–3,000 kg/m2s Lazarek and Black [31] R113 Macrochannels 3.15 mm inner diameter tube Saturated flow boiling – Gungor and Winterton [32] Water and Olopatadine refrigerants (R-11, R-12, R-22, R-113, and R-114) Horizontal and vertical flows in tubes and annuli D = 3 to 32 mm Saturated and subcooled boiling flow 0.008 < p sat < 203 bar; 12 < G < 61.518 kg/m2s; 0 < x < 173%; 1 < q < 91.534 kW/m2 h tp = (SS 2 + FF 2)h sp (17) h sp is calculated Equation 6 S = 1 + 3, 000Bo0.86 (18) Liu and Witerton [36] Water, refrigerants and ethylene glycol Vertical and horizontal tubes, and annuli Subcooled and saturated flow boiling – h nb is calculated by Cooper [35] (Equation 11) Kew and Cornwell [33] R141b Single tubes of 1.39–3.