A CFD study of two-phase frozen flow of air/water through a safety relief valve

M Moftah.S. Moftah Alshaikh, William Dempster

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The air-water two phase critical flows through a safety relief valve commonly used in the refrigeration industry is examined with particular emphasis on the prediction of the critical mass flowrates using CFD based approaches. The expansion of the gas through the valve and the associated acceleration is coupled to the liquid phase and results in changes to the velocity slip with the possibility of influencing the choking conditions and the magnitude of the critical mass flows. These conditions are poorly reported in the literature for safety valves. This paper presents a study where the ability of established two phase multi-dimensional modelling approaches to predict such conditions are investigated. Comparison with the simplified mixture model will show that this model tends to underestimate mass flowrates for medium to high liquid mass fraction. However, the two fluid model can adequately account for the thermal and mechanical non equilibrium for these complex flow conditions with the use of simplified droplet sizing rules.
LanguageEnglish
Pages533-540
Number of pages11
JournalInternational Journal of Chemical Reactor Engineering
Volume13
Issue number4
Early online date1 Dec 2015
DOIs
Publication statusPublished - 30 Dec 2015
Event13th International Conference on Multiphase Flow in Industrial Plants, MFIP13 - Genoa, Sestri Levante, Italy
Duration: 16 Sep 201419 Sep 2014

Fingerprint

Safety valves
Pressure relief valves
Computational fluid dynamics
Water
Air
Liquids
Refrigeration
Gases
Fluids
Industry

Keywords

  • two-phase flow
  • safety valves
  • CFD
  • experiments

Cite this

@article{e237e1c4dc814b41b6db596f78ce3241,
title = "A CFD study of two-phase frozen flow of air/water through a safety relief valve",
abstract = "The air-water two phase critical flows through a safety relief valve commonly used in the refrigeration industry is examined with particular emphasis on the prediction of the critical mass flowrates using CFD based approaches. The expansion of the gas through the valve and the associated acceleration is coupled to the liquid phase and results in changes to the velocity slip with the possibility of influencing the choking conditions and the magnitude of the critical mass flows. These conditions are poorly reported in the literature for safety valves. This paper presents a study where the ability of established two phase multi-dimensional modelling approaches to predict such conditions are investigated. Comparison with the simplified mixture model will show that this model tends to underestimate mass flowrates for medium to high liquid mass fraction. However, the two fluid model can adequately account for the thermal and mechanical non equilibrium for these complex flow conditions with the use of simplified droplet sizing rules.",
keywords = "two-phase flow, safety valves, CFD, experiments",
author = "{Moftah.S. Moftah Alshaikh}, M and William Dempster",
year = "2015",
month = "12",
day = "30",
doi = "10.1515/ijcre-2014-0168",
language = "English",
volume = "13",
pages = "533--540",
journal = "International Journal of Chemical Reactor Engineering",
issn = "1542-6580",
number = "4",

}

A CFD study of two-phase frozen flow of air/water through a safety relief valve. / Moftah.S. Moftah Alshaikh, M; Dempster, William.

In: International Journal of Chemical Reactor Engineering, Vol. 13, No. 4, 30.12.2015, p. 533-540.

Research output: Contribution to journalArticle

TY - JOUR

T1 - A CFD study of two-phase frozen flow of air/water through a safety relief valve

AU - Moftah.S. Moftah Alshaikh, M

AU - Dempster, William

PY - 2015/12/30

Y1 - 2015/12/30

N2 - The air-water two phase critical flows through a safety relief valve commonly used in the refrigeration industry is examined with particular emphasis on the prediction of the critical mass flowrates using CFD based approaches. The expansion of the gas through the valve and the associated acceleration is coupled to the liquid phase and results in changes to the velocity slip with the possibility of influencing the choking conditions and the magnitude of the critical mass flows. These conditions are poorly reported in the literature for safety valves. This paper presents a study where the ability of established two phase multi-dimensional modelling approaches to predict such conditions are investigated. Comparison with the simplified mixture model will show that this model tends to underestimate mass flowrates for medium to high liquid mass fraction. However, the two fluid model can adequately account for the thermal and mechanical non equilibrium for these complex flow conditions with the use of simplified droplet sizing rules.

AB - The air-water two phase critical flows through a safety relief valve commonly used in the refrigeration industry is examined with particular emphasis on the prediction of the critical mass flowrates using CFD based approaches. The expansion of the gas through the valve and the associated acceleration is coupled to the liquid phase and results in changes to the velocity slip with the possibility of influencing the choking conditions and the magnitude of the critical mass flows. These conditions are poorly reported in the literature for safety valves. This paper presents a study where the ability of established two phase multi-dimensional modelling approaches to predict such conditions are investigated. Comparison with the simplified mixture model will show that this model tends to underestimate mass flowrates for medium to high liquid mass fraction. However, the two fluid model can adequately account for the thermal and mechanical non equilibrium for these complex flow conditions with the use of simplified droplet sizing rules.

KW - two-phase flow

KW - safety valves

KW - CFD

KW - experiments

U2 - 10.1515/ijcre-2014-0168

DO - 10.1515/ijcre-2014-0168

M3 - Article

VL - 13

SP - 533

EP - 540

JO - International Journal of Chemical Reactor Engineering

T2 - International Journal of Chemical Reactor Engineering

JF - International Journal of Chemical Reactor Engineering

SN - 1542-6580

IS - 4

ER -