The GasWorks software, brought to you by Accutech , is widely used in the natural gas reticulation industries for the design of industrial and domestic supply networks. GasWorks provides an extensive set of network modelling tools designed to assist the engineer analyse and design distribution, transmission, gathering and plant piping systems conveying natural gas or other compressible fluids. GasWorks offers no fewer than 19 different pipe flow equations.
The design and simulation of gas flow in pipelines presents the engineer with a number of problems. First, the compressibility of the gas needs to be taken into account and therefore its full thermophysical properties need to be known. If the gas is not a pure substance but a mixture of gases such as found in natural gas, then the properties of the mixture need to be determined. A further complexity arises if the gas is not in a single-phase state but comprises both liquid and gas phases. Add to this the number of equations for gas flow friction loss in pipes found in the literature and we have a complex engineering challenge. Computer software provides the solution.
The Graphical Data Interface (GDI) provides map style graphical access to the model data. The GDI allows the inclusion of bitmap (BMP), Drawing Interchange File (DXF), or Shape (SHP) files as a reference background. Using the GDI, the User can draw the model schematic using point-and-click mouse entry, coordinate value entry, or relative distance and angle entry. The GDI provides pop-up data screens for editing and viewing of the various pipe, node and customer data and analysis results.
Partnering GasWorks is the StationManager program - a database application that allows management of various regulator station styles through an easy to use spreadsheet. The data fields allow tracking of station location, description, identification, status, dates, hydraulic configuration, MAOP’s, installed equipment specifications, inspection results, pressure settings, and digital images of the station.
For a more sophisticated approach to gas flow simulation, the software package FluidFlow3 offers a database of more than 900 pure fluids with the ability to merge different fluid streams within a pipe network with the software estimating the thermophysical properties of the resulting mixture. Heat change can also be accommodated. Rather than using the simplifying assumptions used in GasWorks’ equations, FluidFlow3 uses a numerical calculation procedure that solves the conservation equations together with an equation of state for small pipe increments while “marching” down the pipeline. Whilst this method provides a highly sophisticated one-size-fits-all method for single-phase flow, it’s not suitable for 2-phase flow. So here, FluidFlow3 offers a choice of six different approaches, viz Beggs & Brill, Chisholm Baroczy, Drift Flux, Friedel, Lockhart Martinelli and Muller Steinberg Heck (MSH).
The optimum design of a pipe network involves the analysis of a wide range of variables, for instance pipe size versus pressure drop and the associated driver capital and operating costs. AFT Titan not only performs steady-state, single-phase pipe network analysis but also offers state-of-the-art numerical optimization algorithms to intelligently evaluate the complex interaction of system design variables. The system design is repeatedly perturbed and re-analysed to define the shape of the design space, revealing combinations of design parameters that minimize cost. Design constraints specified by the engineer direct the search in areas that satisfy design requirements such as pressure, velocity and compressor pressure rise. Searching continues until an optimum design is found, which is then presented to the user.