Prediction of the maximum full lift safety valve two-phase flow capacity

Lenzing, T.; Friedel, L.; Cremers, J.; Alhusein, M.

doi:10.1016/s0950-4230(98)00014-x

Cited by 26 publications

(31 citation statements)

References 4 publications

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“…The model, reported in [3], can be applied to saturated two-phase mixture at the nozzle inlet. The HFM model supposes that the quality does not change and the vapour is considered an ideal gas undergoing an isoentropic process.…”

Section: Two-phase Flow Through Ideal Nozzlesmentioning

confidence: 99%

“…The HFM model supposes that the quality does not change and the vapour is considered an ideal gas undergoing an isoentropic process. Different formulation of this model are available: the Starkman formulation [13] and the Nastoll formulation [3] were used in the present work.…”

Section: Two-phase Flow Through Ideal Nozzlesmentioning

confidence: 99%

“…Most authors [1][2][3][4][5] suggest that two-phase choked flow through safety valves can be evaluated by simplified two-phase flow models whose approach is similar to the one in single-phase: they suggest to multiply the two-phase choked flow rate through an ideal convergent-divergent nozzle and a twophase discharge coefficient. Even though normally manufacturers provide the discharge coefficient for the liquid and sometimes for gas flow, no such data are provided in two-phase flow.…”

Section: Introductionmentioning

confidence: 99%

“…The authors compared the predictions of two-phase flow rate through ideal nozzle by the Homogeneous Equilibrium Model (HEM), the ω method (first developed by Leung [10] ), Slip Equilibrium Models (SEM), Homogeneous Non Equilibrium models like the one developed by Henry and Fauske in 1970 (HNE) [11] and afterwards improved by Diener and Schimdt (HNE-DS) [1], Equilibrium Rate Model (ERM) [2], Homogeneous Frozen Models (HFM) [3] or by Homogeneous Direct Integration (HDI) and Homogeneous Non-equilibrium Direct Integration (HNDI) methods [4].…”

Section: Introductionmentioning

confidence: 99%

“…Afterwards the authors considered the models of two phase valve discharge coefficient developed by Lenzing [3], Darby [4], and Leung [5] and combined them with the different models of two-phase choked flow in ideal nozzles, in order to evaluate which couple of the two gives the best prediction of experimental data in different thermal-hydraulic conditions.…”

Section: Introductionmentioning

confidence: 99%

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Prediction of two-phase choked-flow through safety valves

Arnulfo¹,

Bertani²,

Salve³

2014

J. Phys.: Conf. Ser.

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Abstract.Different models of two-phase choked flow through safety valves are applied in order to evaluate their capabilities of prediction in different thermal-hydraulic conditions. Experimental data available in the literature for two-phase fluid and subcooled liquid upstream the safety valve have been compared with the models predictions. Both flashing flows and nonflashing flows of liquid and incondensable gases have been considered. The present paper shows that for flashing flows good predictions are obtained by using the two-phase valve discharge coefficient defined by Lenzing and multiplying it by the critical flow rate in an ideal nozzle evaluated by either Omega Method or the Homogeneous Non-equilibrium Direct Integration. In case of non-flashing flows of water and air, Leung/Darby formulation of the two-phase valve discharge coefficient together with the Omega Method is more suitable to the prediction of flow rate.

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Section: Two-phase Flow Through Ideal Nozzlesmentioning

confidence: 99%

Section: Two-phase Flow Through Ideal Nozzlesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Prediction of two-phase choked-flow through safety valves

Arnulfo¹,

Bertani²,

Salve³

2014

J. Phys.: Conf. Ser.

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Reproductive Accuracy of Generic Omega Parameter Safety Valve Two Phase Critical Mass Flow Models Based on Water and Refrigerant R‐134a Data

Friedel¹

2007

Chem Eng & Technol

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The modified Omega method included in ISO/FDIS 4126-10 provides the highest accuracy compared to other modified models frequently used in practice and academia. At the same time, it allows for an exceptionless oversizing of the necessary relief area under all test conditions. Nevertheless, the average or statistical reproductive accuracy is characterized by an unacceptably high logarithmic scatter of about 80 % for fluid dynamic critical steam/water and two-phase refrigerant R134a flow. When applying the method to sizing situations with predicted mass flow qualities in excess of 1 % an acceptably modest oversizing is maintained.

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