Simulation Group Model

A simulation group model is a collection of equipment and branches which, when built, form a connected model representing the flow of fluid/gasses from one or more sources to a destination (usually a flare in this application). In a process simulation model the emphasis moves from equipment/pipe/branches as modelled in 3D, to a connected group of points or nodes, where flow is diverted, split or restricted in some way.

To produce an APS model common E3D components must be mapped onto symbols from the APS Libraries. The following diagram shows the commonly used symbols which form an APS model.

A flow model in APS flows from a source through various components to a sink and a complete model could include several streams which connect in some way. The start of a model is where the fluid stream begins and this is likely to be a source or drum.In terms of the E3D model this could be an equipment nozzle or a branch head if no equipment is present. At the end of the stream the terminal symbol is likely to be a sink or a stack into which the stream flows.

Between these ends the route of the stream is determined by a sequence of node points represented by the remaining symbol types. The APS flow model is calculated by evaluating the flow conditions at each of the node elements taking into account the sizes, components and distances between them.

Two node types, mix and split represent diverting or combining the stream are essentially TEE type elements within E3D. The different symbols are used according to how the fluid flow enters and leaves the component. A mix element has two input streams and one output stream so it "mixes" two streams into one. A split has one input stream and two output streams so it "splits" a stream into two.

An enlarger in APS is the equivalent of a reducer in E3D and is used to increase or reduce the bore size of the incoming stream. The two valve type symbols are used to represent control valves of different types.

Finally, the pipe element is used to represent the connected stream between nodes. The actual pipe data model in APS contains data on length, number of components ,elevation change and bore sizes between the nodes using a single symbol. Conventional valves (gate, globe etc) are listed amongst the pipe components.