A simulation system for simulating the operation of a process network having a set of physical plant elements through which mass flows, wherein the process network includes a plurality of junction nodes at which flow converges or diverges, the plurality of junction nodes including a plurality of nodes identified as base junction nodes, the system comprising:
- a multiplicity of processor implemented simulation modules stored on a computer memory, each of the multiplicity of simulation modules including a process model that models the operation of a different one of the physical plant elements to determine pressures at the different physical plant elements, and including a communication routine that communicates with other simulation modules to communicate the determined pressures, wherein each of the simulation modules includes;
- a memory that stores a definition of a grouped set of nodes associated with a base junction node, the base junction node being one of the plurality of nodes identified as base junction nodes in the plurality junction nodes within the process network, the grouped set of nodes for the base junction node being less than all of the nodes of the process network and including:
- 1) a selected set of junction nodes including the base junction node and one or more further junction nodes that are adjacent to the base junction node, and 2) one or more boundary nodes that are adjacent to at least on of the one or more further junction nodes but not adjacent to the base junction node;
- and
- a routine that executes on a processor to iteratively solve for the pressure for the base junction node during each of a number of simulation cycles using a set of pressure and flow equations based on the grouped set of nodes for the base junction node to calculate the pressure at the base junction node, wherein, the routine iteratively solves for the pressure for the base junction node during a simulation cycle by performing a multiplicity of iterations, wherein during each iteration the routine sequentially solves for the pressure at each of the selected set of junction nodes of the grouped set of nodes for the base junction node using a previously calculated value for the pressures at the others of the selected set of junction nodes in the grouped set of nodes for the base junction node and using fixed values for the pressures at each of the boundary nodes of the grouped set of nodes for the base junction node, and determines a mass flow balance at one or more of the selected set of junction nodes using the calculated pressures to determine if flow balance is achieved at the one or more of the selected set of junction nodes;
- and
- wherein each of the simulation modules is executed during each simulation cycle.