1. Analysis and Design of Distribution Systems for Potable Water using the EPANET model Part 2

2. Modern pipe network models
Kypipes
WaterCAD
CyberNET
EPANET epanet.html

3. EPANET
performs extended period simulation of hydraulics and water quality within pressurized pipe networks.
A network can consist of:
pipes
nodes (pipe junctions)
pumps
valves
storage tanks
reservoirs
EPANET computes at each timestep
flow in each pipe
pressure at each node
height of water in each tank or reservoir,
water “age” (residence time)
concentration of each water quality parameter

4. EPANET Applications Design to ensure adequate flow and pressure
tank elevations and sizes
pipe sizes
size and location of pumps to ensure
assessment and management
use of alternative sources within multiple source system
cost of various pumping schedules
Schedule pipe cleaning and replacement

5. Hydraulic Modeling Capabilities
Computes friction head loss using either Hazen-Williams, Darcy-Weisbach, or Chezy-Manning equations.
Includes minor head losses for bends, fittings, etc.
Models constant or variable speed pumps.
Computes pumping energy and cost.
Models various types of valves including shutoff, check, pressure regulating, and flow control valves

6. EPANET model components --links connected to nodes
EPANET model components --links connected to nodes. Links: pipes, pumps, and control valves. Nodes: junctions, tanks, and reservoirs

7. Steps in Using EPANET
Set program defaults (naming convention, pipe roughness, unit system, head loss formula)
Draw the distribution system (Section 6.1 in manual) by inserting nodes and connecting with links; underlay a graphic if desired
Edit the properties of the objects that make up the system (Section 6.4), eg, pipe length and diameters, nodal elevations
Describe how the system is operated (Section 6.5)
Select a set of analysis options (Section 8.1) – timestep, duration
Run hydraulic/water quality analysis (Section 8.2)
View results (Chapter 9)
Change parameters and repeat as necessary

8. Program User Interface map toolbar
browser
(data and map tabs)
property
editor

9. Project Setup
Project >> Defaults
View >> Options

10. Creating Network using tools on map toolbar

11. Connect nodes with pipes, add pumps, valves and labels

12. Use the map tab of the browser to color-code nodes and pipes according to different properties

13. Set properties for nodes (junctions) and pipes.
First, chose category of object
from the data browser
Then double click in list
or on map to select
Click “Add” icon to create a
new object of current category

14. Set properties for nodes (junctions) and pipes
For junctions, minimum required
information is demand and
elevation.
These will be filled in after you run a simulation

15. Set properties for nodes (junctions) and pipes
• For pipes, minimum required
information is start and end nodes, lengths, diameters, and roughness.
These will be filled in after you run a simulation

16. Set properties for tanks, reservoirs and pumps

17. Pump Curves

18. Set properties for tanks
Minimum information is elevation, a diameter, a minimum, maximum
and an initial water level.

19. Sign on flow indicates direction relative to flow arrow on the map.

20. This allows you to vary nodal demands throughout the day

21. View results on the map

24. Common errors/warnings
“Network is disconnected”
No connecting/open link to all nodes with demands.
“Hydraulic equations unsolvable” Network is disconnected or unrealistic values specified for network properties.
“Pumps cannot deliver flow or head” Pump asked to operate outside range of characteristic curve; turned off if asked to deliver head greater than shutoff head.
“System unbalanced” EPANET cannot converge; can occur if pumps turn on/off or valves open/close from trial to trial.