Fluid Flow mode for the U4 example simulation

The purpose of Fluid Flow mode for this simulation is to show that the network that we designed in Process mode meets the cooling water flow requirements. In Fluid Flow mode, AVEVA Process Simulation moves the entire network to a pressure-balanced solution. We make the following assumptions:

• The Pumps operate on their performance curves.

• All of the Mixers provide a pressure-balanced solution.

• The Pipes use the actual pipe diameter from the pipe schedule table.

• Pipe flows are not based on process requirements like they were in Process mode. AVEVA Process Simulation calculates the Pipe flows based on system hydraulics.

To obtain the correct pressure drop through the Heat Exchangers, it is important that the Wref and DPref values for each Heat Exchanger are correct based on a reference condition for that Heat Exchanger. Usually you obtain this data from the heat exchanger data sheet.

The change to Fluid Flow mode moves Heat Exchanger flows based on the network pressure balance. The Wref and DPref variables in Fluid Flow mode take values from the W and DP values in Process mode. Therefore, AVEVA Process Simulation recalculates the DP value for each individual Heat Exchanger by using the updated pressure-driven flows according to the following equation:

The Trip One Pump Scenario shows how much flow is possible when only one of the two pumps is operating.