scholarly journals Discussion: “Steam Flow Through Safety Valve Vent Pipes” (Brandmaier, H. E., and Knebel, M. E., 1976, ASME J. Fluids Eng., 98, pp. 199–206)

1976 ◽  
Vol 98 (2) ◽  
pp. 206-206
Author(s):  
G. S. Liao
Keyword(s):  
1976 ◽  
Vol 98 (2) ◽  
pp. 199-206
Author(s):  
H. E. Brandmaier ◽  
M. E. Knebel

The flow of steam through a safety valve vent pipe system has been analyzed to provide a design basis for sizing the pipe to prevent blowback of steam. The analysis is based upon the application of modern fluid dynamics to the flow in ejectors and free-jet wind tunnels. The resulting vent pipe design procedure is, in the authors’ opinion, based upon a more realistic analysis than has previously been performed.


Author(s):  
Alton Reich

Abstract Control valves are used to adjust fluid flow rates in an extremely wide variety of applications. This paper discusses a steam flow control valve that is required to operate with a fairly wide range of inlet conditions (steam pressure) and provide effective control over a fairly wide range of steam flow rates. In this particular case a valve design was developed using “classical” methods — a combination of experience and hand calculations. The valve was tested and it did not provide adequate control over the flow for the application. The valve redesign effort used CFD to gain insight into the flow through the valve in order to evaluate control performance before the valve was fabricated and assembled. Several internal geometries were assessed and compared in order to identify two configurations that would meet the flow control requirements. These configurations were fabricated and tested and deemed to be adequate.


Fluids ◽  
2017 ◽  
Vol 2 (4) ◽  
pp. 63
Author(s):  
Miah Alam ◽  
Manabu Takao ◽  
Toshiaki Setoguchi

2016 ◽  
Vol 821 ◽  
pp. 31-38
Author(s):  
Vladimír Hric ◽  
Jan Halama

The paper concerns with the numerical modeling of wet steam flow through a blade cascade in transonic regime with non-equilibrium condensation in 2D. Real thermodynamics of vapor phase is implemented in the way which mostly avoid iterations in order to calculate thermodynamic properties. This equation of state is represented by the function for non-dimensional entropy with independent variables scaled density and scaled internal energy. Other equations of state are used for comparison, namely special gas equation which comes from IAPWS-95 formulation and simple pseudo perfect gas relation. We applied simple homogeneous non-equilibrium approach to model two-phase flow. Laminar compressible Navier-Stokes system of equations is used for the mixture properties. Liquid phase is described by the standard method of moments of droplet number distribution function. We consider obtained numerical results to be in good agreement with the measured data. We note the fact that robust and accurate closure of supplementary liquid system (nucleation rate and droplet growth model) is still not available and most often ad-hoc corrections are proposed by the authors. Results show differences among used equations of state as well. This is apparent mainly in the vicinity of condensation shock region on the suction side.


Author(s):  
Vasilios Kourakos ◽  
Sai¨d Chabane ◽  
Patrick Rambaud ◽  
Jean-Marie Buchlin

Safety devices are of major importance in the nuclear and chemical industry. Examples of such systems are safety valves and rupture disks. The behavior of this type of valve in single-phase flow (gas or liquid) has been described in detail in the literature, while for two-phase flow there is a lack of relative models since the phenomena are much more complex. The design and sizing of this apparatus is an important issue which would prevent its wrong functionality that could cause a hazardous situation. In this paper, a transparent (made in Polymethyl methacrylate) model of a safety valve is studied (1 1/2 in G 3 in); this has allowed full optical access and therefore the identification of the structure of the flow and the observation of the different phenomena occurring. Instead of a spring, used in an actual safety valve, the disk is fixed and its position can vary from completely closed to fully opened position. Thus, the static flow behavior of the valve is examined.


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