5 Water Supply Challenges and Achievements in Constanta County
185
Table 5.2 Technical
parameters for the main duty
points. Old and new Mircea
Vod˘ a pumping station [4]
Head
Parameter
Old pump New pump
H max = 65 m NPSH (m)
8.20
8.50
Pump’s efficiency
(%)
83
90
Absorbed power
(kW)
1440
1328
H min = 56 m NPSH (m)
12.50
11.00
Pump’s efficiency
(%)
79
83
Absorbed power
(kW)
1520
1447
= 90% at its overall efficiency is 86%, which results in an absorbed power amount
of 1328 kW. The new value of the net positive suction head, for this duty point, is
8.50 m which is convenient for proper operation of these pumps.
Furthermore, at the minimum head H min = 56 m, the pump efficiency lowers
down and the absorbed power becomes Pa = 1447 kW, Table 5.2. The pump’s
performance curves indicate a smaller net positive suction head, of 8.20 m. This
newly proposed pump will operate within its optimal range. Nevertheless, the existing
priming installation is recommended to be kept.
Only six pumps in a pumping group were to be replaced. One current pump from
each group has to be equipped with a frequency converter, to operate at variable speed.
This measure will make possible the pumping station to deliver small discharge values
and, consequently, to make considerable energy savings.
The main advantages offered by the new solution consisted of:
• low exploitation costs due to the new possibility to adjust to low discharge values;
• higher efficiency;
• lower consumed power for the same delivered discharge.
5.3.2.2 Lift Irrigation Water Supply Pumping Station
Galesu is a lift irrigation water pumping station, which supplies with water an olericulture area of 3950 ha. The original pumping station had been functioning since
1970.
The pumping station takes water from canal CA 1 and delivers it through two
mains of 1000 mm in diameter and 900 m in length. The static head varies between
H gmin = 26 m and H gmax = 26.35 m [6]. As the pumps deteriorated, the operation
and maintenance costs became unacceptable. The proposed modernization solution
consisted of replacing the internally worn pumps with five new horizontal centrifugal
double flux pumps. The piping system (excepting the two concrete made mains) and
hydraulic equipment were renewed.
185
Table 5.2 Technical
parameters for the main duty
points. Old and new Mircea
Vod˘ a pumping station [4]
Head
Parameter
Old pump New pump
H max = 65 m NPSH (m)
8.20
8.50
Pump’s efficiency
(%)
83
90
Absorbed power
(kW)
1440
1328
H min = 56 m NPSH (m)
12.50
11.00
Pump’s efficiency
(%)
79
83
Absorbed power
(kW)
1520
1447
= 90% at its overall efficiency is 86%, which results in an absorbed power amount
of 1328 kW. The new value of the net positive suction head, for this duty point, is
8.50 m which is convenient for proper operation of these pumps.
Furthermore, at the minimum head H min = 56 m, the pump efficiency lowers
down and the absorbed power becomes Pa = 1447 kW, Table 5.2. The pump’s
performance curves indicate a smaller net positive suction head, of 8.20 m. This
newly proposed pump will operate within its optimal range. Nevertheless, the existing
priming installation is recommended to be kept.
Only six pumps in a pumping group were to be replaced. One current pump from
each group has to be equipped with a frequency converter, to operate at variable speed.
This measure will make possible the pumping station to deliver small discharge values
and, consequently, to make considerable energy savings.
The main advantages offered by the new solution consisted of:
• low exploitation costs due to the new possibility to adjust to low discharge values;
• higher efficiency;
• lower consumed power for the same delivered discharge.
5.3.2.2 Lift Irrigation Water Supply Pumping Station
Galesu is a lift irrigation water pumping station, which supplies with water an olericulture area of 3950 ha. The original pumping station had been functioning since
1970.
The pumping station takes water from canal CA 1 and delivers it through two
mains of 1000 mm in diameter and 900 m in length. The static head varies between
H gmin = 26 m and H gmax = 26.35 m [6]. As the pumps deteriorated, the operation
and maintenance costs became unacceptable. The proposed modernization solution
consisted of replacing the internally worn pumps with five new horizontal centrifugal
double flux pumps. The piping system (excepting the two concrete made mains) and
hydraulic equipment were renewed.