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Motivation



One of the key problems in designing the pipelines and controlling the pipeline fluid transport is to predict the temperature and pressure losses during the stationary fluid transport.

Pipeline flow simulator is addressing this problem. It should account for the varying pipeline trajectory, gravity effects, fluid friction with pipeline walls and varying heat exchange with surroundings.


Definition



Given 

  • space coordinates are  \{ x, \, y, \, z \} with  z-ccordinate facing down to the Earth Centre

  • inflow pipeline coordinates  \{ x_s = 0, \, y_s = 0, \, z_s = 0 \}

  • pipeline trajectory  \{ x_w(l), \, y_w(l), \, z_w(l) \}, where  l = \int_0^l \sqrt{dx^2 + dy^2 + dz^2} = \int_0^l \sqrt{\dot x^2 + \dot y^2 + \dot z^2} dl,  is pipeline length from inflow point  \{ x_s = 0, \, y_s = 0, \, z_s = 0 \}

  • pipeline cross-section area  A(l)

  • earth gravity vector  {\bf g} = (0, \, 0, \, g) where  g = 9.81 \ \rm m/s^2

  • inflow temperature  T_s, inflow pressure  p_s, inflow rate  q_s

  • PVT properties of water  \rho(T, p)\mu(T, p)

  • surroundings initial temperature   T_g(l), thermal diffusivity  a_e(l), thermal conductivity  \lambda_e(l) of surrounding media

  • heat exchange coefficient  U(l) based on pipeline schematics


Simulate


  • along-pipe distribution of stabilized pressure  p(l), flow rate q(l) and average flow velocity  u(l) 

  • along-pipe distribution of fluid flow temperature  T(t, l) after a flow period of time  t when the flow stabilization achieved





In water producing or water injecting wells the friction factor  can be assumed constant  f(l) = f_s = \rm const along-hole ( see  Darcy friction factor in water producing/injecting wells ).



References







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