For empirical models based on the local condition hypothesis, few important parameters give significant correlations on the prediction of CHF (Critical Heat Flux). This work is a preliminary study to develop a generalized CHF correlation in uniformly heated vertical round tubes for water. For this analysis, a total of 8,912 CHF data points from 12 different published sources were used. This database consisted of following parameter ranges: 0.101 ≤ P (pressure) ≤ 20.679 MPa, 9.92 ≤ G (mass flux) ≤ 18,619.39 kg/m2s, 0.00102 ≤ D (diameter) ≤ 0.04468 m, 0.03 ≤ L (length) ≤ 4.97 m, 8.5 ≤ L/D ≤ 792.26, −609.33 ≤ Inlet subcooling ≤ 1,655.34 kJ/kg, 0.11 ≤ qc (CHF) ≤ 21.41 MW/m2, and −0.85 ≤ Xe (exit qualities) ≤ 1.58. Five representative CHF data sets at pressure conditions of 0.101, 5.001, 10, 16 and 20 MPa were selected, analyzed, and compared to evaluate the effects of parameters on the CHF. It has revealed that the major variables which influenced the CHF, other than the system pressure (P), were tube diameter (D), mass flux of water (G), and local true mass fraction of vapor (Xt). Square root of GXt and square root of D were the significant parameters that showed strong parametric trends of the data sets. The results of this study have reaffirmed the feasibility that an advanced generalized CHF correlation for uniformly heated vertical round tubes can be found.

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