Skip to Main Content
The second case study is also a real problem, in the city of Itororó, Brazil. Figure 2 presents the WDN topology, with 1 reservoir, 20 pipes linking 17 demand nodes, 3 loops, and a hydraulic pump with a water catchment level of 222 m, responsible to pump water to the reservoir. Table 6 presents the nodes and pipes characteristic. Available set of seven distinct commercial diameters are presented in Table 7, with the respective costs. In this case, the costs in R$ were converted from USD (USD 1 = R$ 4). The water velocity must be bounded between 0.2 and 3.5 m/s and the minimum required pressure is 15 m for all demand nodes. The Darcy–Weisbach equation is used and a roughness coefficient equal to m for all pipes was considered. The water kinematic viscosity at 20 °C is m2/s. The pump efficiency is 75% and 7,300 h/year is considered as the operation time. The energy cost is 0.134 $/kWh and the annual interest rate is 10%. The lifetime considered is 25 years and the annual increase in the energy is 6%.
Table 6

Nodes elevation and demands and pipe lengths

Node/PipeElevation (m)Demand (L/s)Pipe length (m)
220.5 5.05 324 
215.6 1.91 124 
210.4 3.81 184 
210.5 1.40 206 
209.5 4.35 103 
213.2 3.51 202 
218.5 3.44 134 
230.7 2.48 227 
211.5 3.06 167 
10 213.5 1.85 166 
11 205.5 2.86 152 
12 208.8 6.11 168 
13 215.5 5.09 177 
14 212.6 4.06 225 
15 207.5 8.05 254 
16 219.4 4.26 263 
17 220.5 1.21 133 
18   321 
19   105 
20   169 
Node/PipeElevation (m)Demand (L/s)Pipe length (m)
220.5 5.05 324 
215.6 1.91 124 
210.4 3.81 184 
210.5 1.40 206 
209.5 4.35 103 
213.2 3.51 202 
218.5 3.44 134 
230.7 2.48 227 
211.5 3.06 167 
10 213.5 1.85 166 
11 205.5 2.86 152 
12 208.8 6.11 168 
13 215.5 5.09 177 
14 212.6 4.06 225 
15 207.5 8.05 254 
16 219.4 4.26 263 
17 220.5 1.21 133 
18   321 
19   105 
20   169 
Table 7

Costs for the commercial available diameters for the Itororó WDN

Diameter (m)Cost ($/m)Diameter (m)Cost ($/m)
0.0534 24.16 0.2042 87.62 
0.0756 32.12 0.2520 118.59 
0.1084 47.09 0.2998 152.24 
0.1564 63.80   
Diameter (m)Cost ($/m)Diameter (m)Cost ($/m)
0.0534 24.16 0.2042 87.62 
0.0756 32.12 0.2520 118.59 
0.1084 47.09 0.2998 152.24 
0.1564 63.80   
Figure 2

Itororó WDN.

Close Modal

or Create an Account

Close Modal
Close Modal