Experimental study of critical flow of water at supercritical pressure

Abstract

Experimental studies of the critical flow of water were conducted under steady-state conditions with a nozzle 1.41 mm in diameter and 4.35 mm in length, covering the inlet pressure range of 22.1-26.8 MPa and inlet temperature range of 38-474°C. The parametric trend of the flow rate was investigated, and the experimental data were compared with the predictions of the homogeneous equilibrium model, the Bernoulli correlation, and the models used in the reactor safety analysis code RELAP5/MOD3.3. It is concluded that in the near or beyond pseudo-critical region, thermal-dynamic equilibrium is dominant, and at a lower temperature, choking does not occur. The onset of the choking condition is not predicted reasonably by the RELAP5 code.

Keywords

critical flow / supercritical water-cooled reactor(SCWR) / reactor safety / loss of coolant accident(LOCA)

References

[1] Levy S, Abdollahian D, Healzer J, . Critical-flow data review and analysis. <patent>EPRI-NP-2192</patent>, 1982

[2] Saha P. A review of two-phase steam-water critical flow models with emphasis on thermal non-equilibrium. <patent>BNL-NUREG-50907</patent>, 1978

[3] Lee D H, Swinnerton D. Evaluation of critical flow for supercritical steam-water. <patent>EPRI-NP-3086</patent>, 1983

[4] Mignot G, Anderson M, Corradini M. Supercritical fluid critical flow experiment and analysis. In: 3rd International Symposium on SCWR Design and Technology, SCWR-P047, Shanghai, 2007

[5] Starkman E S, Schrock V E, Neusen K F, . Expansion of a very low quality two-phase fluid through a convergent-divergent nozzle. ASME Trans D, J Basic Engineering, 1964, 86(2): 247-256

[6] Moody F J. Maximum flow rate of a single component, two-phase mixture. ASME Trans C, J Heat Transfer, 1965, 87(1): 134-142

[7] Henry R E, Fauske H K. The two-phase critical flow of one-component mixtures in nozzles, orifices, and short tubes. ASME Trans C, J Heat Transfer, 1971, 93(2): 179-187

[8] Chen Yuzhou, Yang Chunsheng, Du Kaiwen, . An experimental study of critical flow of water at steady-state with pressure of up to 22 MPa. In: Proc 7th International Symposium of Heat Transfer, Beijing, 2008

[9] Trapp J A, Ransom V H. A choked-flow calculation criterion for non-homogeneous, non-equilibrium, two-phase flows. Int J Multiphase Flow, 1982, 8(6): 669-681

[10] Burnel J G. Flow of boiling water through nozzles, orifices and pipes. Engineering, 1947, 164: 572-576

Acknowledgements

The present study was supported by the National Basic Research Program of China (No. 2007CB209800) and the Coordinated Research Project of International Atomic Energy Agency (IAEA Research contract No. 14469/R0).

Notation

D	diameter/mm
G	mass flux/(kg·m-2·s-1)
h	specific enthalpy/(J·kg-1)
L	length/mm
p	pressure/MPa
r	radius/mm
s	specific entropy/( J·kg-1·K-1)
T	temperature/CC
TPC	pseudo-critical temperature/CC
v	specific volume/(m3·kg-1 )
x	quality
ρ	density/( kg·m-3 )
Subscript
b	back, bulk
cr	critical
e	equilibrium
g	vapor
l	liquid
M	measurement
0	inlet
P	prediction
t	throuat

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg