Simulation of Transients in Natural Gas Networks via A Semi-analytical Solution Approach

TL;DR

This paper introduces a semi-analytical solution method for simulating transient flows in natural gas networks, significantly improving computational speed and maintaining accuracy compared to traditional finite difference methods.

Contribution

The paper develops a novel semi-analytical solution approach that allows larger grid cells and faster simulations for natural gas transients, with simplified nonlinear terms for further efficiency.

Findings

Achieves higher computational efficiency than finite difference methods.

Maintains accuracy with larger grid cells and simplified nonlinear terms.

Validated on pipeline and network cases with positive results.

Abstract

Simulation and control of the transient flow in natural gas networks involve solving partial differential equations (PDEs). This paper proposes a semi-analytical solutions (SAS) approach for fast and accurate simulation of the natural gas transients. The region of interest is divided into a grid, and an SAS is derived for each grid cell in the form of the multivariate polynomials, of which the coefficients are identified according to the initial value and boundary value conditions. The solutions are solved in a ``time-stepping'' manner; that is, within one time step, the coefficients of the SAS are identified and the initial value of the next time step is evaluated. This approach achieves a much larger grid cell than the widely used finite difference method, and thus enhances the computational efficiency significantly. To further reduce the computation burden, the nonlinear terms in the model are simplified, which induces another SAS scheme that can greatly reduce the time consumption and have minor impact on accuracy. The simulation results on a single pipeline case and a 6-node network case validate the advantages of the proposed SAS approach in accuracy and computational efficiency.