PROJ00527

• Contract/PO #: FS0024X
• Contractor Name: Florida Water Conservancy District
• Contract Type: Loan
• Water District: 0
• County: La Plata
• Loan Projects - Doc Type: Feasibility Study

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1) a flow is assumed and the friction loss is calculated
c

using 0.2139 Q2;

2) the friction loss is subtracted from the gross head to
obtain the net head; 'and

3) the turbine performance curve is checked to see if'the
net head and the assumed flow match; if they don't then
another flow is assumed and the net head is recalculated.
This is continued until the net head and flow match.
(This is why the performance curve was essential.)

Table 7.1 shows the results of the iterations for various
gross head-values, for the Worthington Pump.

TABLE 7.1
Net Head

Gross Head (ft.)

Net Head (ft.)

Flow (cfs)

196
180
170
160
150
140
130
120
110
100

157
144
137
129
122
114
106
99
91
83

13 .4
12.8
12.4
12.0
11.5
11.0
10.5
10.0
9.4
8.8

The flow and net head values are for the Worthington Pump
model 10LNT14A, 1210 rpm. The one problem with the selected model
is that it cannot utilize net head over 140 feet which is 175 feet
gross head. The maximum head and flow for the model is 140 feet
and 12.6 cfs, respectively; so the unit efficiency will drop or
the flow will have to be throttled to reduce the head and flow
when the gross head is greater than 175 feet. Alternate models,
such as the 10LNT22A, would be able to utilize the full head range

7.0-13