Setting a Good Balanced Model
- Always start with inflow known and pressure unknown
- Must have one unknown inflow for each flow isolated sub-system in the model, at the node where inflow is set to unknown, make the pressure be known (Flow Isolated Region)
- Must have one known pressure for each pressure isolated sub-system in the model (Pressure Isolated Region)
- Other known pressure points can be downstream or upstream of a compressor or regulator, in doing so make sure the compressor or regulator control status is unknown.
- The only nodes which can be both pressure and inflow known are downstream or upstream of a compressor or regulator.
Follow this process to build a good model
- Understand the Pressure Isolation and Flow Isolation
- Pressure Isolated Elements (pressure changing legs)
- Compressor which is turned on, regulator in unknown pressure control, closed valve, closed check valve, etc…
- Flow Isolated Elements (flow limiting legs or zero flow legs)
- Closed valve, flow control regulator, closed check valve, shut – in compressor with closed valve in off mode, etc.
