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KSME International Journal

, Volume 15, Issue 9, pp 1302–1310 | Cite as

Modeling and simulation for PIG with bypass flow control in natural gas pipeline

  • Tan Tien Nguyen
  • Sang Bong Kim
  • Hui Ryong Yoo
  • Yong Woo Rho
Thermal Engineering · Fluid Engineering · Energy and Power Engineering

Abstract

This paper introduces modeling and simulation results for pipeline inspection gauge (PIG) with bypass flow control in natural gas pipeline. The dynamic behaviour of the PIG depends on the different pressure across its body and the bypass flow through it. The system dynamics includes: dynamics of driving gas flow behind the PIG, dynamics of expelled gas in front of the PIG, dynamics of bypass flow, and dynamics of the PIG. The bypass flow across the PIG is treated as incompressible flow with the assumption of its Mach number smaller than 0.45. The governing nonlinear hyperbolic partial differential equations for unsteady gas flows are solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used for solving the steady flow equations to get initial flow values and the dynamic equation of the PIG. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. Simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of the PIG with bypass flow under given operational conditions of pipeline.

Key Words

Pipeline Inspection Gauge (PIG) Method Of Characteristics (MOC) Bypass Flow 

Nomenclature

A

Pipe cross section [m2]

c

Wave speed [m/s]

C

Linear damping coefficient of the PIG [Ns/m]

Cc

Convection heat transfer coefficient [W/m2K]

d

Internal diameter of pipe [m]

dvalve

Bypass valve diameter [m]

Fb

Braking force [N]

Ff

Friction force per unit pipe length [N/m]

Ffp

Friction force between the PIG and pipeline’s wall including [N]

Ffpsta

Static friction force

Ffpdyn

Dynamic friction force

Fp

The PIG driving force [N]

h

The opening height of valve [m]

k

Pipe wall roughness [m]

K

Wear factor per distance travel [N/m]

KSC

Sudden constraction loss coefficient

KSE

Sudden expansion loss coefficient

Ktotal

Total loss coefficient

LPIG

Length of the PIG [m]

m

Hydraulic mean radius of pipe [m]

M

Weight of the PIG [kg]

p

Flow pressure [N/m2]

q

Compound rate of heat inflow per unit area of pipe wall [W/m2]

S

Perimeter of pipe [m]

T

Flow temperature [K]

Text

Seabed temperature [K]

u

Flow velocity [m/s]

uV

Flow velocity through valve [m/s]

vPIG

Velocity of the PIG [m/s]

x

Distance from pipe inlet [m]

xPIG

Position of the PIG [m]

X

Denote flow parameter values

Greeks

γ

The ratio of specific heat

ν

Kinetic viscosity of flow [m2/s]

ϱ

Flow density [kg/m3]

Subscripts

L, R, M, N, S, O, P

Denote the grid points, and

0, l

Denote the points at inlet and outlet of pipeline

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References

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Copyright information

© The Korean Society of Mechanical Engineers (KSME) 2001

Authors and Affiliations

  • Tan Tien Nguyen
    • 1
  • Sang Bong Kim
    • 1
  • Hui Ryong Yoo
    • 2
  • Yong Woo Rho
    • 2
  1. 1.Department of Mechanical Engineering, College of EngineeringPukyong National UniversityPusanKorea
  2. 2.Korea Gas Corporation (KOGAS)Kyunggi-doKorea

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