HYDRAULIC CALCULATION FOR
CHILLED WATER PUMPS TOTAL DYNAMIC HEAD
RE Reynolds number
F Liner loss factor
Loss m per 100 m
dh(1) Liner loss
dh(2) Local loss
DH Total loss
Total heal (DH+GH) / pipe
Accumulative Pressure
For CHILLED WATER PUMPS
V Mean Velocity
COLBROOK Formula
GH Static heal
(1)
Total local factors
Head loss calculation using
1/1
m
m/s
1/1
1/1
m
m
m
m
m
m
2
0.1
680
42.8
1
1
203
22
0.1
1360
85.7
4
1
C-D
6"
GI
154
8
0.1
679
42.8
5
D-E
8"
GI
203
42
0.1
756.23 47.6
4
E-F
6"
GI
154
32
0.1
491.41
0.2 gate valve 1
2.0 check valve
154
GI
8.0 Globe valve
GI
8"
l/s
0.2 Flexible
6"
B-C
Q Flow rate
A-B
GPM
1
31
1.0 discharge outlet
mm
2.0 Strainer
K Pipe roughness
m
0.5 reducer
L Pipe length
mm
0.9 tee
ID Pipe Inner diameter
DN
0.3 elbow ( 90 leg.)
DN Nominal diameter
no.
0.2 elbow ( 45 leg.)
no. part of pipe
Local factors of fittings
1
5.4
2.29756 354008.19 0.01882 3.29 0.07
1.45
1.52 1.52 1.519
2.1
2.65406 538084.07 0.01755 3.11 0.68
0.75
1.44 1.44 2.956
1.5
2.29418 353487.59 0.01882 3.28 0.26
0.4
0.66 0.66 3.621
1
2.1
1.47579 299202.44 0.01817 0.99 0.42
0.23
0.65 0.65 4.272
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
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
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
1.8
1.63217 57256.581
0.026
10.1 1.71
0.24
1.96 1.96
K - FCU
3/4"
GI
21
19
0.1
5.5
0.35
12.3
1.00422 21048.545 0.0264
6.47 1.23
0.63
1.86 1.86 16.91
12
7
TOTAL
211
1 1
1
1
3
1
3
1
1
1
25 20 1
2
2.2549
Pressure drop in chiller
=
12.00 m
Pressure drop in FCU
=
1.32 m
two way valve loss
=
1.00 m
total friction loss
=
18.86 m
Total dynamic head supply
=
33.18 m
Total dynamic head return
=
21.18 m
19
11.9 17
18.86
DN Nominal diameter
ID Pipe Inner diameter L Pipe length
K Pipe roughness
no. DN mm m mm GPM l/s Safty factor
total dynamic head
Total local factors GH Static heal
V Mean Velocity
RE Reynolds number
F Liner loss factor
Loss m per 100 m dh(1) Liner loss dh(2) Local loss DH Total loss Total heal (DH+GH) / pipe Accumulative Pressure
1.0 discharge outlet
2.0 Strainer
0.5 reducer
0.9 tee
0.3 elbow ( 90 leg.)
0.2 elbow ( 45 leg.)
2.0 check valve
8.0 Globe valve
0.2 Flexible
0.2 gate valve
Q Flow rate
no. part of pipe
Local factors of fittings
1/1 m m/s 1/1 1/1 m m m m m m
20% = 10.87 m
= 65.24 m
CHILLED WATER PUMPS
Project : Agriculture Bank - Gizan
Page ( 1 )
Head Loss Calculations: The total friction loss Hs Consist of: Hs
Hs1 + Hs2
=
Where:
Hs1 Hs2
…………………………………………………….…… (1) : Friction loss Inside pipes : Friction loss inside fittings
Linear friction loss equation: Hs =
J . L …………………………………… ……………………………………... .... (2)
J = l . V² / ( 2 g D ) ………..…………………………………………………………….. (3) Where:
J L l V g D
: linear loss factor : length Of the pipe (m.) : friction loss factor (COLBROOK-WHITE formula) : velocity of water (m/s) : gravity acceleration (9.81 m/s²) : pipe inside diameter (m.)
COLBROOK WHITE formula:……………………………………………………………….. ( 4 ) 1 sqr(l)
= - 2 x log [
Where:
K D RE
k 3.7 x D
+
2.51 Re x sqr( l )
: pipe inside Surface roughness (m.) : pipe inside diameter (m.) : REYNOLD’S no. is given as follows: (1/1)
RE = V x D / n …………………………………………………………………………. ( 5 ) Where:
V = Q/A
n V D
: water viscosity= ( n = 1E-06 : velocity of water (m/s) : pipe inside diameter (m.)
m2/s)
………………………………………...………………………………………. ( 6 )
Where:
Q A
Data for the first pipe :
: flow rate (m³/s) : cross section are of the pipe (m²) 6" GI 168.3 mm 7.11 mm
D = K =
0.1541 m 0.0001 m
Pipe type & size 6" Out side diameter (mm) Wall thickness (mm) : pipe inside diameter (m.) : pipe inside Surface roughness (m.)
)
Project : Agriculture Bank - Gizan
Flow :
Page ( 2 )
Q = 680.0 GPM = 42.84 l/s = 0.04284 2 A = px D /4 =
V = Q/A = Re = V x D / n = 1 sqr(l)
m³/sec
3.14 x 0.154 ² / 4 = 0.01865 m²
2.298 m/s 2.298 x 0.1541 / 0.000001 = 354008.19 0.0001 3.7 x 0.154
= - 2 log [
+
2.51 x sqr( l ) 354008.2
]
By solving above equation : l=
0.01882 0.01882 x 2.2976 x 2.298 2 x 9.81 x 0.1541
J = l . V² / ( 2 g D ) = Loss m per 100 m = J x 100 =
0.03286 x 100 m = 3.286
= 0.03286 m/m 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) : Gravity acceleration (9.81 m/s²) : Velocity of water (m/s) : Sum of local loss factors
Where:
G V SUM ZE
SUM ZE =
gate valve Flexible Globe valve check valve elbow ( 45 leg.) elbow ( 90 leg.) tee reducer Strainer discharge outlet Total local factors
HS2
SUM ZE . V ² / ( 2 . g )
=
HS(2) = SUM ZE.x V² / ( 2 g ) =
1 0 0 1 0 1 1 0 1 0
5.4 x
x x x x x x x x x x
0.2 0.2 8 2 0.2 0.3 0.9 0.5 2 1 =
= = = = = = = = = =
2.2976 X 2.2976 2 x 9.81
0.2 0 0 2 0 0.3 0.9 0 2 0 5.40
= 1.4529 m
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
Project : Agriculture Bank - Gizan
Page ( 3 )
Data for the second pipe :
D = K = Flow :
8" GI 219.1 mm 8.18 mm
Pipe type & size 8" Out side diameter (mm) Wall thickness (mm)
0.2027 m 0.0001 m
: pipe inside diameter (m.) : pipe inside Surface roughness (m.)
Q = 1360.0 GPM = 85.68 l/s = 0.08568 2
3.14 x 0.203 ² / 4 = 0.03228 m²
A = px D /4 = V = Q/A = Re = V x D / n = 1 sqr(l)
m³/sec
2.654 m/s 2.654 x 0.2027 / 0.000001 = 538084.07 0.0001 3.7 x 0.203
= - 2 log [
By solving above equation :
l=
+
2.51 x sqr( l ) 538084.1
0.01755
0.01755 x 2.6541 x 2.654 2 x 9.81 x 0.2027
J = l . V² / ( 2 g D ) = Loss m per 100 m = J x 100 =
]
0.03108 x 100 m = 3.108
= 0.03108 m/m 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 Flexible Globe valve check valve elbow ( 45 leg.) elbow ( 90 leg.) tee reducer Strainer discharge outlet Total local factors
HS2
SUM ZE . V ² / ( 2 . g )
=
HS(2) = SUM ZE.x V² / ( 2 g ) =
0 0 0 0 0 4 1 0 0 0
2.1 x
x x x x x x x x x x
0.2 0.2 8 2 0.2 0.3 0.9 0.5 2 1 =
= = = = = = = = = =
2.6541 X 2.6541 2 x 9.81
0 0 0 0 0 1.2 0.9 0 0 0 2.10
= 0.7539 m
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 :