Modelação de transitórios lentos em redes de gás

André Ramos Pereira

Key information

Authors:

André Ramos Pereira (André Ramos Pereira)

Supervisors:

Luís Manuel De Carvalho Gato (Luís Manuel De Carvalho Gato); João Carlos de Campos Henriques (João Carlos de Campos Henriques)

Published in

11/13/2018

Abstract

When the management of a project involves high risks, it is necessary to simulate its structure. In a natural gas supply chain at high pressure, it is recommended to assume particular values that ensure the analysis efficiency. Therefore, it was employed a slow transient flow to determine the working conditions and its temporal fluctuations due to numerous impositions. A finite element method with transient flow was implemented to analyse the natural gas transport inside the pipelines The numerical model used is based on a simplification of the balances of mass, momentum and energy for the simulation of slow transients of a compressible fluid. A python code has been adapted and further improved, particularly a reduction of its simulation time. Three cases were simulated. Firstly, the actual network state was simulated, followed by the hypothetical introduction of a new lot that connects Celorico da Beira and Vale de Frades, and, as a consequence, the Spanish network. The third simulation also included the lot between Celorico da Beira and Vale de Frades however, Campo Maior's valve was assumed to be closed. The first simulation conclusions are threefold: the pipeline network is properly dimensioned; the pressure values are in conformity with the requirements; and, the maximum total injection capacity of gas is never exceeded. The network is prepared to receive a new lot. In the last simulation, it was concluded that closing Campo Maior's valve would implicate changes in the network. Consequently, two alternatives were evaluated, upon which one could fulfill its requirements.