This paper illustrates the main features of a new software package (DTS) for the management of gas transmission networks. The principal function of the package is to minimize the consumption of fuel gas at the compression stations. Some applications demonstrate that the use of DTS can lead to remarkable energy savings.
In the last few years the engineering companies have been more and more frequently called to provide tools to optimize the management of gas transportation systems. This demand is justified by the considerable energy savings (in the order of 10%) attainable with suitable software tools. For this reason Snamprogetti, in collaboration with Tema, developed a new package, named DTS (Dispatching Tutorial System), for the management of gas transportation networks. DTS, besides providing the traditional simulation functions, (steady and dynamic state), includes the new optimization functions as it can both determine the optimal configuration of compression stations under steady transport conditions and define the sequence of operations to be carried out to change from a transport configuration to a different one. A particular attention has been paid to the modelling of compression stations and units (compressors and turbines) which have been studied in detail as they are of the utmost importance in the evaluation of the optimal transport configuration.
The general architecture of a management system is depicted in Figure 1. The main components of this system are the following:
DTS is the core of the management system. It acquires field data through the SCADA Interface Module, manages all the necessary data-bases and supports the different system users with a suitable man-machine interface. The different possible users of DTS are the following:
This user interacts through DTS with the Planning Module, assignes the priorities and defines the minimum and maximum quantities to be delivered to each gas user. The manager of the distribution system can also carry out long term analysis and planning through the steady and unsteady simulation modules. With this function he can examine future alternative scenarios and individuate critical conditions for the transportation system.
These users can define alternative environments. By different environments we mean either the actual transportation system, or parts of the same or hypothetical networks used for training purposes. The process engineers load and manage data of: equipment, pipe and physical constraints, for example minimum and maximum pressures at the different nodes of the network. In addition the process engineers can use DTS to size extensions of the existing networks or as calculation tool in the design of a new pipeline.
These users control the operation of the network and determine the optimal policy to meet the gas demand. The DTS enables them to single out the sequence of operations to be carried out for an optimal management of the transport network meeting the constraints imposed by the network.