Study on the two-phase critical flow through a small bottom break in a pressurized horizontal pipe

Two-phase critical flows through some breaks of pressurized pipe systems are calculated by an improved critical flow model. These phenomena have many difficulties in predicting the two-phase critical flow rates at the break points mainly due to the inaccuracies of the critical flow model. Further, the case of critical flow through the small bottom break of horizontal pipe, the accuracy of a quality prediction model is also important as well as the critical flow model itself. In this study, an improved critical flow model is introduced which is based on a new sound speed criterion derived from the hyperbolic two-fluid model for non-equilibrium flow and this model is implemented to a system analysis code. Following to the vertically upward flows with quality variation and Marviken tests as benchmark problems, the small bottom break of a pressurized horizontal pipe is calculated and discussed in some details. The assessment results on the critical flow test through a small bottom break in a horizontal pipe show the importance of the accuracy of the critical flow model as well as that of the quality prediction model to reduce the relative errors.

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Measurement of the oil holdup for a two-phase oil-water flow through a sudden contraction in a horizontal pipe

Journal of Physics Conference Series ◽

10.1088/1742-6596/501/1/012015 ◽

2014 ◽

Vol 501 ◽

pp. 012015 ◽

Cited By ~ 1

Author(s):

L P M Colombo ◽

M Guilizzoni ◽

G M Sotgia ◽

S Bortolotti ◽

L Pavan

Keyword(s):

Water Flow ◽

Two Phase ◽

Horizontal Pipe ◽

Sudden Contraction ◽

Flow Through ◽

Oil Water

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The Two-Phase Critical Flow of One-Component Mixtures in Nozzles, Orifices, and Short Tubes

Journal of Heat Transfer ◽

10.1115/1.3449782 ◽

1971 ◽

Vol 93 (2) ◽

pp. 179-187 ◽

Cited By ~ 259

Author(s):

Robert E. Henry ◽

Hans K. Fauske

Keyword(s):

Critical Pressure ◽

Single Phase ◽

Pressure Ratio ◽

Stagnation Pressure ◽

Experimental Results ◽

Critical Flow ◽

Two Phase ◽

Transfer Rates ◽

Critical Flow Rate ◽

Flow Through

The critical flow of one-component, two-phase mixtures through convergent nozzles is investigated and discussed including considerations of the interphase heat, mass, and momentum transfer rates. Based on the experimental results of previous investigators, credible assumptions are made to approximate these interphase processes which lead to a transcendental expression for the critical pressure ratio as a function of the stagnation pressure and quality. A solution to this expression also yields a prediction for the critical flow rate. Based on the experimental results of single-phase compressible flow through orifices and short tubes, the two-phase model is extended to include such geometries. The models are compared with steam-water, cryogenic, and alkali-metal experimental data.

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