Sh. Chang et al., DERIVATION OF MECHANISTIC CRITICAL HEAT-FLUX MODEL FOR WATER-BASED ONFLOW INSTABILITIES, International communications in heat and mass transfer, 23(8), 1996, pp. 1109-1119
The critical heat flux (CHF) is a major parameter which determines the
cooling performance and therefore the prediction of CHF with accuracy
is of importance for the design and safety analysis of nuclear power
plant (NPP). In this study, the mechanistic CHF model and correlation
for water are derived based on flow excursion (or Ledinegg instability
) criterion and the simplified two-phase homogeneous model. The relati
onship between CHF for the water and the principal parameters such as
mass flux, heat of vaporization, heated length-to-diameter ratio, vapo
r-liquid density ratio and inlet subcooling is derived on the develope
d correlation. The developed CHF correlation predicts very well at the
applicable ranges, 1 < P < 40 bar, 1,300 < G 27,00 kg/m(2)s and inlet
quality is less than -0.1. The overall mean ratio of predicted to exp
erimental CHF value is 0.988 with standard deviation of 0.046. Copyrig
ht (C) 1996 Elsevier Science Ltd