An economic method for simulating steady-state conditions in gas transport systems

An economic iterative method is proposed for simulating steady-state conditions in complex gas transport systems of any topology. The method exploits a fast algebraic pipe model with periodic identification which is used to adjust the model to the steady-state conditions under consideration and to provide the required accuracy of calculation. The identification procedure is based on the solution of stationary hydrodynamic equations. The gas transport system is represented as a list of pipes and a list of joints (nodes). As an initial approximation, we define gas pressures and temperatures in the nodes thus setting boundary conditions for the steady-state flow. In the global iterations of the method, the pressures and temperatures are updated so as to make flow disbalance tend to zero. The method allows parallel computing on multiprocessor computers. It is implemented as a separate module in the VOLNA software. Its efficiency is demonstrated through a sample calculation for the gas transport system. A number of related issues are considered, including simulation accuracy, peculiarities in the solution of stationary equations, correctness of calculation setup etc. The method can be used in combination with any other model of piped compressible gas.