HYDRAULIC CALCULATION
FOR
CHILLED WATER PUMPS
TOTAL DYNAMIC HEAD
Head loss calculation using ( 1 ) COLBROOK Formula For CHILLED WATER PUMPS no. mm m mm GPM l/s 0.2 0 .2 8 .0 2 .0 0 .2 0 .3 0 .9 0 .5 2 .0 1 .0 1/1 m m/s 1/1 1/1 m m m m m m A - B 6" GI 154 2 0.1 680 42.8 1 1 1 1 1 5.4 2.29756 354008.19 0.01882 3.29 0.07 1.45 1.52 1.52 1.519 B - C 8" GI 203 22 0.1 1360 85.7 4 1 2.1 2.65406 538084.07 0.01755 3.11 0.68 0.75 1.44 1.44 2.956 C - D 6" GI 154 8 0.1 679 42.8 5 1.5 2.29418 353487.59 0.01882 3.28 0.26 0.4 0.66 0.66 3.621 D - E 8" GI 203 42 0.1 756.23 47.6 4 1 2.1 1.47579 299202.44 0.01817 0.99 0.42 0.23 0.65 0.65 4.272 E - F 6" GI 154 32 0.1 491.41 31 2 1 1.5 1.66036 255828.18 0.01919 1.75 0.56 0.21 0.77 0.77 5.042 F - G 4" GI 102 20 0.1 293.96 18.5 2 2 2.4 2.2549 230586.1 0.02077 5.26 1.05 0.62 1.67 1.67 6.717 G - H 2 1/2" GI 62.7 13 0.1 99.22 6.25 1 4 3.9 2.02578 126975.78 0.02363 7.88 1.02 0.82 1.84 1.84 8.558 H - I 2" GI 52.5 20 0.1 77.18 4.86 4 3.6 2.24785 117967.29 0.0246 12.1 2.41 0.93 3.34 3.34 11.9 I - J 1 1/2" GI 40.9 16 0.1 44.58 2.81 4 3.6 2.13351 87345.974 0.0255 14.4 2.31 0.84 3.15 3.15 15.05 J - K 1 1/4" GI 35.1 17 0.1 25.04 1.58 3 1 1.8 1.63217 57256.581 0.026 10.1 1.71 0.24 1.96 1.96 17 K - FCU 3/4" GI 21 19 0.1 5.5 0.35 1 3 1 1 1 12.3 1.00422 21048.545 0.0264 6.47 1.23 0.63 1.86 1.86 16.91 TOTAL 211 1 1 1 25 20 1 2 12 7 19
Pressure drop in chiller = 12.00m
Pressure drop in FCU = 1.32m
two way valve loss = 1.00m
total friction loss = 18.86m
Total dynamic head supply = 33.18m
Total dynamic head return = 21.18m
no . pa rt o f p ip e DN N o m in a l d ia m e te r Fl e xi b le ID P ip e I n n e r d ia m e te r L P ip e l e n g th K P ip e r o u g h n e ss Q Fl o w r a te 18.86 d h (1 ) L in e r lo ss S tr a in e r d isch a rg e o u tl e t A ccu m u la ti ve P re ssu re D H To ta l lo ss To ta l h e a l (D H + G H ) / p ip e V M e a n V e lo ci ty RE R e yn o ld s n u m b e r To ta l lo ca l fa ct o rs DN ch e ck va lve L o ss m p e r 1 0 0 m d h (2 ) L o ca l lo ss GH S ta ti c h e a l F L in e r lo ss fa ct o r G lo b e va lve
Local factors of fittings
e lb o w ( 4 5 l e g .) e lb o w ( 9 0 l e g .) te e re d u ce r g a te va lve
no. mm m mm GPM l/s 0.2 .20 8.0 2.0 0.2 0.3 0.9 0.5 2.0 1.0 1/1 m m/s 1/1 1/1 m m m m m m no . pa rt o f p ip e DN N o m in a l d ia m e te r Fl e xi b le ID P ip e I n n e r d ia m e te r L P ip e l e n g th K P ip e r o u g h n e ss Q Fl o w r a te d h (1 ) L in e r lo ss S tr a in e r d isch a rg e o u tl e t A ccu m u la ti ve P re ssu re D H To ta l lo ss To ta l h e a l (D H + G H ) / p ip e V M e a n V e lo ci ty RE R e yn o ld s n u m b e r To ta l lo ca l fa ct o rs DN ch e ck va lve L o ss m p e r 1 0 0 m d h (2 ) L o ca l lo ss GH S ta ti c h e a l F L in e r lo ss fa ct o r G lo b e va lve
Local factors of fittings
e lb o w ( 4 5 l e g .) e lb o w ( 9 0 l e g .) te e re d u ce r g a te va lve Safty factor 20%= 10.87m
CHILLED WATER PUMPS
Project : Agriculture Bank - Gizan Page ( 1 )
Head Loss Calculations:
The total friction loss Hs Consist of:Hs = Hs1 + Hs2 ……….…… (1) Where: Hs1 : Friction loss Inside pipes
Hs2 : Friction loss inside fittings Linear friction loss equation:
Hs = J . L ……… ………... .... (2) J = l . V² / ( 2 g D ) ………..……….. (3) Where: J : linear loss factor
L : length Of the pipe (m.)
l : friction loss factor (COLBROOK-WHITE formula) V : velocity of water (m/s)
g : gravity acceleration (9.81 m/s²) D : pipe inside diameter (m.)
COLBROOK WHITE formula:……….. ( 4 ) 1
sqr(l)
Where: K : pipe inside Surface roughness (m.) D : pipe inside diameter (m.)
RE : REYNOLD’S no. is given as follows: (1/1)
RE = V x D / n ………. ( 5 ) Where: n : water viscosity= ( n = 1E-06 m2/s)
V : velocity of water (m/s) D : pipe inside diameter (m.)
V = Q / A ………...………. ( 6 ) Where: Q : flow rate (m³/s)
A : cross section are of the pipe (m²) Data for the first pipe : 6"GI Pipe type & size 6"
168.3 mm Out side diameter (mm) 7.11 mm Wall thickness (mm) D = 0.1541 m : pipe inside diameter (m.)
K = 0.0001 m : pipe inside Surface roughness (m.)
= - 2 x log [ k + 2.51 )
Project : Agriculture Bank - Gizan Page ( 2 ) Flow : Q = 680.0 GPM = 42.84 l/s = 0.04284 m³/sec A = p x D2 / 4 = 3.14 x 0.154 ² / 4 = 0.01865 m² V =Q / A = 2.298m/s Re = V x D / n = 2.298 x 0.1541 / 0.000001 = 354008.19 1 sqr(l) x sqr( l )
By solving above equation :
l = 0.01882
Loss m per 100 m = J x 100 = 0.03286 x 100 m = 3.286 m / 100m Pipe length L = 2.0 m
dh(1) Liner loss = J x L = 0.03286 x 2.0 = 0.066 m Local losses equation is given as follows:
HS2 = SUM ZE . V ² / ( 2 . G ) …..……….. (7) Where: G : Gravity acceleration (9.81 m/s²)
V : Velocity of water (m/s) SUM ZE : Sum of local loss factors
SUM ZE = gate valve 1 x 0.2 = 0.2
Flexible 0 x 0.2 = 0 Globe valve 0 x 8 = 0 check valve 1 x 2 = 2 elbow ( 45 leg.) 0 x 0.2 = 0 elbow ( 90 leg.) 1 x 0.3 = 0.3 tee 1 x 0.9 = 0.9 reducer 0 x 0.5 = 0 Strainer 1 x 2 = 2 discharge outlet 0 x 1 = 0
Total local factors =
HS2 = SUM ZE . V ² / ( 2 . g )
DH Total loss = HS1 + HS2 = 0.066 + 1.453 = 1.519 m
Total heal (DH+GH) / pipe = Static head + Friction losses ………. ( 8 ) = 0.0 + 1.519 = 1.519 m = - 2 log [ 0.0001 + 2.51 3.7 x 0.154 J = l . V² / ( 2 g D ) = HS(2) = SUM ZE.x V² / ( 2 g ) = 5.4 x 2.2976 X 2.2976 2 x 9.81 5.40 ] = 0.03286 m/m = 1.4529 m 0.01882 x 2.2976 x 2.298 2 x 9.81 x 0.1541 354008.2
Project : Agriculture Bank - Gizan Page ( 3 )
Data for the second pipe : 8"GI Pipe type & size 8" 219.1 mm Out side diameter (mm)
8.18 mm Wall thickness (mm) D = 0.2027 m : pipe inside diameter (m.)
K = 0.0001 m : pipe inside Surface roughness (m.) Flow : Q = 1360.0 GPM = 85.68 l/s = 0.08568 m³/sec A = p x D2 / 4 = 3.14 x 0.203 ² / 4 = 0.03228 m² V = Q / A = 2.654m/s Re = V x D / n = 2.654 x 0.2027 / 0.000001 = 538084.07 1 sqr(l) x sqr( l )
By solving above equation : l =
Loss m per 100 m = J x 100 = 0.03108 x 100 m = 3.108 m / 100m Pipe length L = 22.0 m
dh(1) Liner loss = J x L = 0.03108 x 22.0 = 0.684 m Local losses equation is given as follows:
HS2 = SUM ZE . V ² / ( 2 . G )
SUM ZE = gate valve 0 x 0.2 = 0
Flexible 0 x 0.2 = 0 Globe valve 0 x 8 = 0 check valve 0 x 2 = 0 elbow ( 45 leg.) 0 x 0.2 = 0 elbow ( 90 leg.) 4 x 0.3 = 1.2 tee 1 x 0.9 = 0.9 reducer 0 x 0.5 = 0 Strainer 0 x 2 = 0 discharge outlet 0 x 1 = 0
Total local factors =
HS2 = SUM ZE . V ² / ( 2 . g )
DH Total loss = HS1 + HS2 = 0.684 + 0.754 = 1.438 m Total heal (DH+GH) / pipe = Static head + Friction losses
= 0.0 + 1.438 = 1.438 m Total Head for pipe 1 & 2 = 1.519 + 1.438 = 2.956 m
Other pipes are calculated same as above, All data and results are arranged in the following table : ] = 0.03108 m/m = 0.7539 m J = l . V² / ( 2 g D ) = 2.10 HS(2) = SUM ZE.x V² / ( 2 g ) = 2.1 x 2.6541 X 2.6541 2 x 9.81 0.01755 538084.1 = - 2 log [ 0.01755 x 2.6541 x 2.654 2 x 9.81 x 0.2027 3.7 x 0.203 0.0001 + 2.51
