Diesel Driven Emergency Feedwater Pump to avoid starvation of water from drum during WAPDA & main feewater
pumps failure
DUTY / CASEEmergency Diesel Driven Feed water pump (taking suction from Dearerator and discharged to Boiler drum via main feedwater line)
CONDITIONS
Material Pumped Water
P.T=Pumping Temperature (C) 158
m=Flowrate (t/h) **Design 35.0 Normal 35 C
Density (kg/m3) 909.2
u=Viscosity (mPa.s) 1 Pvp*=Vapour Pressure (kPa) 250
Pipe (Material) CS
d,Actual ID (mm) Suction 110 Discharge 76
* At Pumping Temperature
**Note:
Calculated flow based upon expertimental drum Level drop rate from trasient/tripping analyis of unit-02 due to grid failure) dated 6/12/2018 (22.31 hr) generating
FRICTION HEAD LOSS ON SUCTION SUCTION FITTINGS & VALVES & STRAIGHT PIPE
Fluid Velocity (m/s) = 1.126 HEAD(m)
Total Equivalent Suct. length (m)
Reynolds No. = 1.126E+05 40
Friction Factor = 0.020 - See notes for Calculation Method
Pressure Drop - m fluid / 100m eq. length = 1.157
Total Friction Head loss (including 15% safety factor) 0.532 (m)
SUCTION & DISCHARGE HEADS SUCTION DISCHARGE
Dearerator Pressure m 22.420 SYSTEM POWER
14.500 * Efficiency (Estimated)= 0.7 (<1)
Water. Level (above pump) m
1419.000 Estimated Shaft Power= ### (KW)
Total Fric. Head Loss(plus Vel Head) -0.597
36.323
Suc. Head Sum,metres of Water,abs.
DYNAMIC HEAD
Discharge Head Sum 1419.00 m Information highlighted in BLUE are required entries
Suction Head Sum -36.32 m Values Highlighted in GREEN are calculated values
TDH=Total Dynamic Head 1382.68 m
NPSH
Suction Head Sum 36.32 m
Pvp -28.05 m
NPSH Available 8.28 m
CENTRIFUGAL PUMP CALCULATION SHEET
Notes and Assumptions
DATA ENTRY
Information highlighted in BLUE are required entries
Values Highlighted in GREEN are calculated values
ACTUAL PIPE DIAMETERS
Nominal Actual Inside Diameter
Pipe Size Schedule 40 Schedule 80 PTFE Lined
In In mm In mm In mm
1 1.049 26.64 0.957 24.31 0.78 19.81
1.5 1.610 40.89 1.500 38.10 1.31 33.27
2 2.067 52.50 1.939 49.25 1.82 46.23
3 3.068 77.92 2.900 73.66 2.80 71.12
4 4.026 102.26 3.826 97.18 3.76 95.50
5 5.047 128.19 4.810 122.17 - -
6 6.065 154.05 5.761 146.33 - -
8 7.981 202.72 7.625 193.68 - -
10 10.020 254.51 9.564 242.93 - -
EQUIVALENT LENGTHS Enter type and factor for
each Valve or Fitting followed by the Number.
Factors for Valves (open) and Fittings
Gate 0.34 Diaphr 4.27 Swing Chk 3.35
Globe 8.54 Plug Valve 0.4690 l.r. or WEld ell0.52
wye 4.27 90 std Elb. 0.76 Std Tee(side out) 1.52
Angle 4.27 45 std Elb. 0.4
FRICTION HEAD LOSS CALCULATIONS
Reynolds No. = Fluid Velocity x Fluid Density x Actual Diameter
Fluid Viscosity
If Re > 2100 (Formula taken from Std T2.3 Std 5, Approximate Moody Formula)
Friction Factor = 0.0055 x [ 1 + ( 20,000 x Pipe Roughness + 1000000 )]^0.33
[ Pipe Diameter Reynolds No. )]
or
If Re < 2100
Friction Factor = 64
Reynolds No.
Pressure Drop = 5100 x Friction Factor x Velocity^2
Diameter
Type of Pipe Pipe Roughness (mm)
Drawn Tubing (Copper, Glass, Stainless Stee 0.0015
Commercial Steel Pipe 0.046
Asphalt Dipped Cast Iron Pipe 0.122
Galvinised Iron Pipe 0.152
Bare Cast Iron Pipe 0.26
Concrete Pipe 0.3 - 3.0
Riveted Steel Pipe 0.9 - 9.0
