Indian Journal of STEAM Vol.01 Issue-01 Sept.

2020

MODIFICATION AND ANALYSIS OF

GLOBE VALVE USING COMPUTATIONAL
FLUID DYNAMICS
1*
Yogesh M. Kalke, 2Gaurav A. Gaurkhede, 3Ganesh H.Kawade
1,2,3
Department of Automobile Engineering, D Y Patil University Ambi, Pune , India
(*Corresponding Author E-mail yogesh.kalke@dyptc.edu.in)
________________________________________________________________________________________________________

Abstract: The aim of this paper is to determine and analyze the flow characteristic through CFD for Globe valve and to decrease
losses inside the present valve and increase mass flow rate. To this aim, the flow path inside the valve is modeled and flow is
analyzed to determine the flow characteristic which is quite accurate and reliable. The analysis results thus obtained could be used
design the shape of the physical path of flow, which could improve the flow characteristic and optimize the valve design.

In the present study, CFD analysis of a specific SPIRAX-TROL fully opened globe Valve LE 31 DN 50 design has been carried
out to understand its performance and reliability during the high pressure flow of steam. The control valve mass flow rate or Kv
was experimentally measured and numerically predicted. The equal percentage (E) Globe valve was represented in the study.
The numerical (simulation) study presented in this showed that the valve Kv and the inherent valve characteristic could be
accurately predicted using symmetric flow model. In addition, the study demonstrates the usefulness of simplified CFD analysis
for relatively complex 3-D flows. The analyses have been performed by applying the commercial computational fluid dynamics
(CFD) code, CFX, to obtain the solution of the flow field through a globe valve.

Keywords - Computational Fluid Dynamics (CFD), Globe control valve, Mass flow rate, Pressure drop ratio.
_______________________________________________________________________________________________________
1. INTRODUCTION 1. An actuator coupled to the valve spindle would provide
valve movement.
Valve control the fluid flow and pressure in a system or a The major constituent parts of globe valves are:1) The body,
process. The selection of their types, design and material 2) The bonnet, 3)The valve seat and valve plug, or trim, 4)
plays a vital role in the performance and reliability of any The valve spindle (which connects to the actuator), 5) The
system. A number of researchers have experimented and sealing arrangement between the valve stem and the bonnet.
analyzed valves for all its parts, fluid types, operating Figure is a diagrammatic representation of a single seat two-
parameters, discharge coefficient and have improved the port globe valve. The difference in upstream pressure (P1)
valve technology. Now, with the emergence of robust and downstream (P2) of the valve, against which the valve
computational fluid dynamics (CFD) tools and must close, is known as the differential pressure (DP).
powerful computers, the analysis of valve performance, and
thus the job of designing valves to suit a particular application
can be done much faster. Control valves are used throughout
in many process industries for controlling volumetric flow
rates. One of the most common types of control valves is the
single seat globe valve. It consists of three main components:
body, trim, and actuator. The body of the valve houses the
trim, which is made up of the plug and seat, and the actuator
positions the plug. Past design strategies have relied heavily
on experimental and to a lesser extent analytical techniques to
analysis of valve. More recently, designers of fluid handling
equipment have begun using Computational Fluid Dynamics
~ CFD! for product development and

optimization. In this work control valve design tools were

developed which utilize the technology of CFD. In particular,
simplified analyses are used that would be more useful for
smaller companies having fewer R & D resources [1]. Globe
valves are frequently used for control applications because of
their suitability for throttling flow and the ease with which Fig. 1 Flow through two-port globe valve[6]
they can be given a specific 'characteristic', relating valve
opening to flow. The typical globe valve is shown in Figure Overview of SPIRA-TROL globe control valve [7]

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 Indian Journal of STEAM Vol.01 Issue-01 Sept. 2020

The Spira-Trol Globe Control valves are general purpose Here, Kv for DN 50=36, P1=2.5bar, P2=1.5bar, x=0.4
control valves that can be engineered to solve both
complex and basic requirements. Its robust construction
makes them long-lasting and easy to maintain, while its
modular design makes it easy to specify, reducing spares = 1078.77 kg/hr
inventory requirements. SPIRA-TROL is a range of two-
port single seat globe valves with cage retained seats. For further CFD analysis, this flow rate is used as a reference
When used in conjunction with a pneumatic actuator they flow rate.
provide characterized modulating or on/off control.
3. MODEL FOR FLUIDIZATION STUDY

a. Simulation Model of Present

Valve.

Fig.2 Overall dimensions of SPIRA-TROL valve with actuator [8]

VALVE SIZE A B C
DN 50 230 80 132 Fig.3 Symmetry section of 3-D DN50 valve body, with fluid domain
.

Valves need to be measured on their capacity to pass fluid. Fig.3 shows model geometry which is filled with fluid known
To enable fair comparison, valves are sized on a capacity as fluid domain.
index or flow coefficient “Kv”.
Kv= Flow rate in m3/hr of water at a defined temperature,
typically between 5oC and 40oC, that create pressure drop
of one bar across a valve orifice. here, Kv value of
SPIRAX-TROL globe Valve LE 31 DN 50 is 36, taken
from Technical information sheet of Spirax Marshall Ltd.

2. SIMPLE SIZING ROUTINE FOR GLOBE

VALVES IN STEAM SERVICE [6]
The flow and expansion of steam through a control valve
is a complex process. There are a variety of very complex
sizing formulae available, but a pragmatic approach,
based on the 'best fit' of a mathematical curve to empirical
results, is shown in following Equation. For globe valves
throttling saturated steam .

Equation 1
Where: ms = Mass flow rate (kg / h) Kv=Valve flow
coefficient (m³ / h bar) P1=Upstream pressure (bar)
x= Pressure drop ratio = (P1-P2)/P1 P2=Downstream
pressure (bar)

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 Indian Journal of STEAM Vol.01 Issue-01 Sept. 2020

B) Computational model: I.CFD post: Result for Present SPIRA TROL fully
opened Globe Valve -:
Fig.4 shows symmetric Geometry with valve plug cavity
and upper port for stem and plug is closed while preparing
fluid domain, because we focused on fluid flow path which
is used for ANSYS CFX analysis.

Table 1.Details of Boundary Conditions: Boundary Physics

Domain Boud
ary
– in
Default Type INLET
Fig.4. Geometry with valve plug cavitySteam Properties: Domain
Location IN
Settin
Saturation temp. =139.023 0c gs
Flow Direction Normal to Boundar
Sp.Enthalpy of steam (hg) = 2.7326E06J/kg Condition
Density of steam=1.9142kg/m3 Flow Regime Subsonic
Sp.volume of steam (Vg) =0.5224m3/kg Heat Transfer Total Temperature
Sp.entropy of steam (Sg) =6939.49J/kg Total Temperature 139.023 [C]
Mass And Momentum Mass Flow Rate
Sp.Heat of Steam (Cp) =2227.03J/kgK
Mass Flow Rate 2.9966e-01 [kg s^-1]
Turbulence Medium Intensity and
Note: All values are taken from a case study Eddy ViscosityRatio
Packaged Plant Room System (PPRS) For Hot Boun
dary -
Water generation. out
Type OUTLET
4. DOMAIN DEFINITION AND BOUNDARY Location OUT
CONDITION Settin
gs
The simulation of control valve was performed using Flow Regime Subsonic
ANSYS CFX 12. The k-epsilon Model was applied in Mass And Momentum Average Static Pressure
order to simulate fluid flows. Domain consists of one fluid Pressure Profile 5.0000e-02
Steam-continuous fluid throughout the domain. Blend
Boundaries are defined as according to locations viz. Inlet, Relative Pressure 1.5000e+00 [bar]
Outlet, Wall, and Symmetry. Pressure Averaging Average Over Whole Outlet
Boun
dary
WAL
Type WALL
Location WALL
Settin
gs
Heat Transfer Adiabatic
Mass And Momentum No Slip Wall
Wall Roughness Rough Wall
Roughness value 25micron
Boun
dary-
Sym
metry
Type Symmetry
Location Symmetry

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 Indian Journal of STEAM Vol.01 Issue-01 Sept. 2020

Fig.7 Complete Geometry with modification.

Fig.7 shows modified DN 50 Valve body where Flow of fluid
open to valve seat from inlet of valve which minimizes eddies
at Region 2 due to aerodynamic nature of flow and flow open
the outlet zone after valve seat which minimizes eddies at
Region 1.

Computational model:

Fig.5 Pressure contour for present valve Fig.8 indicates the modified symmetric Geometry with
meshing which is used for ANSYS CFX analysis
In this CFD POST for Present SPIRA TROL DN 50 globe
control valve, for all boundary conditions which are
mentioned in table 1,gives INLET Pressure P1=4.8849bar.in
FUNCTION CALCULATOR. We can calculate (PD)
Pressure drop as (P1-P2) i.e.

4.8849-1.5 =3.384 bar.Kv=36.Using this PD we got Mass

flow rate by Eqn.1 So, mass flow rate become 1600 kg/hr.

Fig.6 Showing Eddies at Region 1 and Region 2 in present

valve.

The present fully opened globe valve Fig.6 shows unwanted

eddies in two region viz. Region 1 which at above the valve
seat and Region 2 which is at below the valve seat. By
modifying flow domain and hence present valve body which
minimizes the eddies in the flow region we can increases the
mass flow rate through the same DN50 control valve as shown
in next topic. Fig.8 Modified Geometry with meshing

5. MODIFIED MODEL OF SPIRA-TROL DN50 GLOBE As in this Modification II) Steam Properties and III)
CONTROL VALVE. Domain definition and Boundary Condition are taken as
same which are used in Present Control valve. This is
Fig.7 shows complete Geometry as same with INLET, helpful to compare in CFD POST results, computed mass
OUTLET, AND VALVE SEAT Diameter i.e. DN 50.but, flow rate between both valves.
some modification of flow domain.

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 Indian Journal of STEAM Vol.01 Issue-01 Sept. 2020

[5] C. Mylswami, “Flow analysis in valves – theoretical vs

6. RESULT AND DISCUSSION experimental”, Articles & Technical papers.
[6] Steam process Technical Information sheet,
CFD post: Results for Modified SPIRA TROL Globe Control
SpiraxSarco.
Valve:
[7] Steam and Control system Book, SpiraxSarco
Ltd.2008.
[8] Raghu Nair, “Steam engineering center Book volume
2”, Forbes Marshall Ltd.
[9] LinaD‟Suza , “Steam engineering center Book volume
3”, Forbes Marshall Ltd.

Fig.9 Pressure contour of Modified Valve

In this CFD POST for Modified SPIRA TROL DN 50
globe control valve, for all boundary conditions which are
mentioned in table1, gives INLET Pressure P1=5.4060
bar in FUNCTION CALCULATOR. We can calculate
(PD) Pressure drop as (P1-P2) i.e. 5.4060-1.5 = 3.906 bar
with Kv=36. Using this PD we got Mass flow rate by
Eqn.1 is 1620 kg/hr.

7. CONCLUSION:

The Result of this analysis is modified valve gives 20Kg/hr

maximum mass flow rate through same DN50 compared to
present DN50 valve. With modification it satisfies customer
increasing demand and save his money. The money that
customer lost to satisfy slight increase in the demand of mass
flow of steam for Steam system Heat exchanger or any other
application this reason lead to shift choice of valve from DN50
to DN 80 and finally increases in flange size, increase in inlet
pipe size, out let pipe size ,weight and overall cost of process.

8.References
[1] James A. Davis and Mike Stewart, “Predicting Globe
Control Valve Performance-CFD Modeling”
University of Arkansas, Vol. 124, Pg.772-777 Sept.
2002
[2] JariKirmanen and VesaLempinen, “Rotary Globe
Valve – A novel innovation in flow control” Valve
World 2008 Conference,Pg.522-529, Maastricht,
the Netherlands.
[3] AditiOza, SudiptoGhosh and KanchanChowdhury,
“CFD Modeling of Globe Valves for Oxygen
Application”, 16th Australasian Fluid Mechanics
Conference, Pg.1356-1363, December 2007
[4] Mr.B.Rajkumar “Globe Valve Design Optimization
&Trends”, L&T Integrated Engineering Services,
Fluids Handling Principles and practice, Pg.212-
234, 2nd edition

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