JIAO Bo, YANG Dongyu. Prediction of entrainment fraction at onset of annular flow based on 2006 CHF look-up table[J]. CIESC Journal, 2014, (8): 2948-2953.
DOI:
JIAO Bo, YANG Dongyu. Prediction of entrainment fraction at onset of annular flow based on 2006 CHF look-up table[J]. CIESC Journal, 2014, (8): 2948-2953.DOI: 10.3969/j.issn.0438-1157.2014.08.014.
Prediction of entrainment fraction at onset of annular flow based on 2006 CHF look-up table
The critical heat flux (CHF) of gas-liquid flow plays an important role in the safety of industrial equipment. At present
the liquid film model is widely used for predicting critical heat flux in gas-liquid annular flow. It consists of onset of annular flow
entrainment fraction for the onset point and the equilibrium state
inception criteria for droplet entrainment
droplet deposition and entrainment rates
which all have decisive effect on prediction accuracy. Most parameters in this model can be determined by some empirical correlations valid under different conditions. However
up to now
the entrainment fraction for the onset of annular flow is always assumed. In this paper
the normalized data of the 2006 CHF look-up table adopted widely
especially in the nuclear industry
were used. The liquid film model was built for the limiting quality region. The entrainment fraction at the onset of annular flow was obtained when the predicted CHF of the model met the values in the look-up table. The empirical correlation including the Weber number and the Reynolds number of liquid was provided. Its prediction could mostly make the errors within ±30%.