THREE factors determine industry-acceptance of a fluid flow, pipe network analysis program.
The first is that the simulation of steady-state compressible and incompressible flows through ‘real’ pipe networks must use a robust friction loss and heat transfer model.
Equally important is the ability to accurately simulate the hydraulic performance of line equipment such as pumps, fans and control valves because in some instances, the so-called 'minor' losses of bends, tees, wyes and valves etc may be far more significant than the pipe friction losses.
The second factor is the need for a high quality graphical interface providing a clear schematic of the pipe system and allowing visualisation of flow directions and display of relevant advice on calculated equipment performance.
The third requirement is a good reporting and communications system allowing the exchange of design data between colleagues and clients.
Three years of intense programming effort and data acquisition have resulted in a new process and fluid flow simulation program called FluidFlow3. During its development each of the above three requirements was given high priority.
Friction loss and heat transfer calculations depend on an accurate estimation of the process fluid's physical and thermodynamic properties.
FluidFlow3 comes standard with a database of more than 800 fluids and uses a wide range of estimation techniques to determine these properties. Data was sourced from some of the latest references.
FluidFlow3 allows different fluids to enter the network from boundary locations and to combine or 'mix' at junctions.
The database structure allows the automatic determination of the mixture's thermo-physical properties. Currently only liquid or gas mixtures are allowed but a future development of the software will simulate 2-phase liquid/gas flows.
As well as the fluids database, FluidFlow3 has ten user-definable equipment databases including a full range of pipe schedules and types, valves, pumps, fans, and relief devices etc.
Other databases include pipe material and insulation thermal conductivity. Examples of pipeline equipment items are accumulators, reciprocating pumps and compressors, rotating positive displacement pumps, cyclones, shell and tube exchangers, plate exchangers, cooling towers, jacketed vessels, bursting discs and 3-way valves.
FluidFlow3: Fluids Database
This comprehensive fluid and equipment resource combined with well-tested friction and pressure loss models provides for an accurate determination of flows and pressures throughout complex pipe networks.
Temperature effects of pressure changes, heat loss or gain from the surroundings and heat exchange made at each network component make heat transfer an automatic part of the network flow calculations.
Fluid temperatures are specified at boundary components - the software calculates all other temperatures including fluid phase states.
Gas calculations make no simplifying assumptions of ideality, adiabatic or isothermal processes etc.
Pressure losses are determined by solving the momentum and physical property equations simultaneously. This means more accurate results, particularly at higher Mach numbers.
FluidFlow3 allows the pipe network flowsheet or schematic to be displayed in orthogonal or isometric view.
A Data Inspector is synchronised with the flowsheet so that the flowsheet is always displayed at the same time as a component's entered data or calculated results are shown on the Inspector.
A wide range of messages is displayed when the calculation is complete. These may simply be advice, such as the velocity of flow in a pipe is above the user-defined desirable maximum or a more serious warning such as a pump is operating with insufficient net positive suction head.
The ability to easily navigate around large and complex flowsheets, to immediately visualise flow directions, the graphical display of pump, fan and equipment performance characteristics and the wide range of warning and advice messages provide the engineer with an intuitive appreciation of how the network is performing. Bottlenecks, inappropriate equipment selection and likely problems are immediately apparent.
Finally, it's important to be able to communicate designs and results with other engineers and clients. FluidFlow3 has an inbuilt report writer with output in HTML, PDF and Word format. Output can also be to Excel.
Accutech is the Perth-based distributor of the software.