CALCULATION HFO / DO DRAIN PUMP SIZING
A
15/06/07
PRELIMINARY ISSUE
REV
DATE
DESCRIPTION OF REVISION
PMK INL SIGN PRE’D
TAI INL SIGN CHKD
KN INL
SIGN PM
OWNER
WEST COAST POWER PRIVATE LIMITED PROJECT
300 MW CCPP, KERAWALAPITIYA SRILANKA
EPC CONTRACTOR
LAKDHANAVI LIMITED CIVIL CONTRACTOR
LTL PROJECTS (PVT) LTD
ENGINEERS FOR EPC CONTRACTOR
FICHTNER CONSULTING ENGINEERS (INDIA) PVT LIMITED CHENNAI, INDIA
PROJECT NUMBER
DOCUMENT NUMBER
DOCUMENT TYPE
REVISION
7856
7856-ME-DSN-131-004
-
A
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
TABLE OF CONTENTS
1.0
GENERAL ...................................................................................................... 3
2.0
REFERENCE DOCUMENTS............................ .............................................. 3
3.0
DESIGN INPUTS............................................................................................3
4.0
ASSUMPTIONS.................... .......................................................................... 3
5.0
DESIGN CODES ............................................................................................ 4
6.0
DESIGN CALCULATIONS ............................................................................. 4
7.0
RESULTS ....................................................................................................... 6
ANNEX - I : PIPE SIZING CALCULATIONS .......................................................................... 7 ANNEX – II : PIPE THICKNESS CALCULATIONS ................................................................. 8 ANNEX – III : PRESSURE DROP SUMMARY........................ ................................................ 9 ANNEX – IV : UNLOADING AREA HFO/DO DRAIN PUMP SIZING CALCULATIONS........ 10 ANNEX – V : FORWARDING AREA HFO/DO DRAIN PUMP SIZING CALCULATIONS ..... 11
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
Page : 2 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant 1.0
GENERAL This document provides the HFO/DO Drain Pump sizing calculations.
2.0
REFERENCE DOCUMENTS The following documents have been referred in carrying out this calculation. i) ii) iii) iv)
Plot Plan DBR - Fuel Oil System Flow diagram - Fuel oil system GA of Untreated HFO storage tank
3.0
DESIGN INPUTS
3.1
General
3.2
4.0
: : : :
00-7856-G-001 7856-ME-DBR-131-001 10-7856-M-026 10-7856-M-108
•
Maximum allowable stress (S) for Carbon steel (A 106 Gr. B) is considered as 17.1 ksi (1202.26 kg/cm²) for seamless pipes. (Refer Table A1 - Appendix A of ASME B31.1a)
•
Weld joint efficiency (E) for Carbon steel (A 106 Gr. B) is considered as 1.0 for seamless pipes. (Refer Table A1 - Appendix A of ASME B31.1a)
•
Material coefficient (y) is considered as 0.4. (Refer Table 104.1.2(A) of ASME B31.1a)
•
Corrosion allowance (A) is considered as 1.5 mm.
•
Manufacturing tolerance (tol) is considered as 12.5%.
•
The design pressure (P) is the maximum sustained pressure, which is the shut-off 2 pressure of the system. Design pressure of 15 bar (a) [15.30kg/cm (a)] is considered adequate.
•
The design temperature for the piping is considered as 60°C.
Drain Pump Sizing Criteria
•
The design velocity is limited to 0.9 m/s at suction side and 1.5 m/s at the discharge side of the Drain oil pump.
•
Specific gravity of Drain oil at operating temperature is considered as 0.97.
•
Kinematic viscosity of Drain oil at operating temperature is considered as 1000cSt.
•
Vapour pressure of Drain oil at operating temperature is considered as 0.2mlc (Preliminary data).
ASSUMPTIONS
•
Pressure drop across suction strainer is considered as 0.45mlc.
•
The pipe routing considered for pressure drop calculations is preliminary and is subject to changes based on finalised piping layout
•
Roughness of the pipe is considered as 0.05mm.
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
Page : 3 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant 5.0
DESIGN CODES The following codes, standards and publications have been referred
•
ASME B31.1 Addenda-2005 : Power Piping
•
ASME B36.10
•
Flow of fluids – Crane hand book.
: Welded & Seamless wrought steel pipe
6.0
DESIGN CALCULATIONS
6.1
Line Sizing Calculation The pipe inner diameter is calculated based on design flow rate and allowable velocity
4 × (Q / 3600)
=
ID
π × V
Where, ID Q V
= = =
Inside diameter of pipe (m) 3 Design Flow rate (m / h) Velocity of flow (m / s)
Based on the calculated inner diameter of the steel pipe, a standard pipe is selected. 6.2
Pipe Wall Thickness Calculation Using the internal fluid pressure, outer diameter and allowable stress of the material, the minimum pipe wall thickness is calculated as per ASME B 31.1a, clause 104.1.2 by,
P × OD + ( + ) 2 SE Py
t m =
t m+ t = t m ×
A
100 100 − tol
Where, tm t m+ t P OD S E y A tol
= = = = = = = = =
Minimum required wall thickness (mm) Minimum required wall thickness with manufacturing tolerance (mm) 2 Internal design pressure (kg/cm ) Outside diameter of pipe (mm) 2 Maximum allowable stress in material due to internal pressure (kg/cm ) Weld joint efficiency Material coefficient Corrosion allowance (mm) Manufacturing tolerance (%)
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
Page : 4 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
Based on calculated minimum wall thickness a standard pipe thickness is selected. For the selected pipe thickness, the maximum pressure that can be withstood by the pipe is calculated as follows:
2 × S × E × (t s − A ) OD − 2 y (t s − A)
P max =
ts
=
Selected pipe thickness (mm)
For detailed calculations refer ANNEX – I & II 6.3
Pressure Drop Calculation
6.3.1
Criteria for Pressure Drop Calculation A) Pressure drop in the fuel oil piping is calculated using Darcy's equation
H f =
H f =
f LV
2
2gd 4f ' LV
2
2gd
Where, Hf f
= =
f' L V d g
= = = = =
Pressure drop in the piping (mlc) Darcy's friction factor for pipe (which is 4 times the Chen's friction factor) Chen's friction factor length of pipe (m) Velocity of the fluid (m/s) Internal diameter of the pipe (m) 2 Acceleration due to gravity (9.81 m/s )
Reynolds number (Re) is calculated by following equation
=
Re
ρ Vd µ
Where, ρ
µ
= =
3
Density (kg/m ) Viscosity (kg/m sec)
Chen's Friction factor (f ') for piping is calculated by following equation
k 1 5.0452 d log A4 = - 4 log Re 3.7065 f '
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
Page : 5 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant Where, 1.1098
k d A4 =
7.149 + 2.8257 Re
k
0.8981
= Roughness of the pipe (mm)
B) For valves and fittings the pressure drop is calculated as follows:
H ft = K
V
2
2 g
Where, H ft
=
Pressure drop in valves and fitting in mlc.
K
=
Resistance co-efficient of fitting as per “Flow of Fluids” by Crane.
For pressure drop summary refer ANNEX - III
6.4
HFO/DO Drain Pump Sizing Calculations The detailed Drain pump sizing calculations are carried out for the HFO/DO Unloading area and HFO/DO Forwarding area to determine the Total Developed Head (TDH), Available NPSH and Estimated Shaft power. The detailed calculations are furnished in ANNEX – IV & V.
7.0
RESULTS The results of calculation and final selected parameters for the Unloading and Forwarding area HFO/DO Drain pump are tabulated below
7.1
7.2
Unloading area HFO/DO Drain Pump Number of working pumps Pump type
: :
Rated capacity of the pump Pump design TDH Available NPSH Estimated shaft power
: : : :
1 Positive displacement, Single screw, Vertical tank mounted type. 3 5 m /hr 50 mlc 10.20 mlc 1.65 kW
Forwarding area HFO/DO Drain Pump Number of working pumps Pump type
: :
Rated capacity of the pump Pump design TDH Available NPSH Estimated shaft power
: : : :
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
1 Positive displacement, Single screw, Vertical tank mounted type. 3 5 m /hr 50 mlc 10.20 mlc 1.65 kW
FICHTNER India
Page : 6 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
ANNEX - I : PIPE SIZING CALCULATIONS
Sl. No.
Selected pipe details
Flow rate
Limiting Velocity
Required ID of the pipe
NB
OD of the pipe
m /h
3
m/s
mm
-
mm
SCH
mm
mm
m/s
5
1.5
34.34
50
60.3
80
5.54
49.22
0.73
5
1.5
34.34
50
60.3
80
5.54
49.22
0.73
Location
Thickness
Available ID of the pipe
Calculated velocity
HFO/DO Unloading area
1
Pipe line from Drain oil pump outlet to Untreated HFO tank recirculation nozzle inlet HFO/DO Forwarding area
2
Pipe line from Drain oil pump outlet to Untreated HFO tank recirculati on nozzle inlet
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
Page : 7 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
ANNEX – II : PIPE THICKNESS CALCULATIONS
PARTICULARS
DATA
UNIT
-
HFO/DO Unloading area Pipe line from Drain oil pump 1 outlet to Untreated HFO tank recirculation nozzle inlet
HFO/DO Forwarding area Pipe line from Drain oil pump 2 outlet to Untreated HFO tank recirulation nozzle inlet
SELECTED PIPE SIZE
NB
50
50
OUTER DIAMETER OF THE PIPE
mm
60.30
60.30
-
SA 106 Gr B
SA 106 Gr B
kg / cm²(a)
15.30
15.30
°C
60
60
kg / cm²
1202.26
1202.26
mm
1.50
1.50
EFFICIENCY FACTOR
-
1
1
VARIABLE COEFFICIENT
-
0.4
0.4
%
12.5
12.5
MINIMUM REQUIRED THICKNESS
mm
1.88
1.88
WITH TOLERANCE
mm
2.15
2.15
SELECTED PIPE SCHEDULE
SCH
80
80
PROVIDED THICKNESS
mm
5.54
5.54
kg / cm²
170.22
170.22
DESCRIPTION
MATERIAL DESIGN PRESSURE DESIGN TEMPERATURE ALLOWABLE STRESS CORROSION ALLOWANCE
MANUFACTURING TOLERANCE
MANUFACTURING
MAXIMUM WITH STANDING PRESSURE
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
Page : 8 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
ANNEX – III : PRESSURE DROP SUMMARY
Pressure Drop Calculation S. No
1
2
Pressure drop bar mlc
Location HFO / DO Unloading area Pressure drop in piping from Drain oil pump outlet to Untreated HFO tank recirculation nozzle inlet HFO / DO Forwarding area Pressure drop in piping from Drain oil pump outlet to Untreated HFO tank recirculation nozzle inlet
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
1.9626
20.625
3.5274
37.069
Page : 9 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
ANNEX – IV : UNLOADING AREA HFO/DO DRAIN PUMP SIZING CALCULATIONS 1
Total Number of pumps
1
2
Number of operating pumps
1
3
Total flow per pump
4
Density of drain oil
5
Capacity of the drain oil tank
I
HEAD CALCULATION
(m³ / h) 3
(kg / m ) 3
m
5 970 2
I. SUCTION SIDE :
1
Available pressure
(mlc)
10.65
(Atmospheric Pressure : 1.01325 bar a )
2
Static Head
(mlc)
0 .20
(Ass umed min.s ubmerge nce in the tank)
3
Friction loss in the piping
(mlc)
0.00
(Not applicable)
4
P re ss ur e d ro p i n s uct io n s tr ai ne r
( mlc )
0 .4 5
( Pr eli min ar y d at a)
Available Suction Head [ Atmospheric pressure + Static head in the tank -
(mlc)
10.40
10.65
5
Pressure drop in suction strainer ] II. DISCHARGE SIDE :
1
Pressure required at destination
(mlc)
(Atmospheric Pressure : 1.01325 bar a )
2
Static head required
(mlc)
11.635 (From GA of untreated Heavy fuel
3
F ri cti on lo ss in t he p ip in g
( ml c)
2 0. 62
4
Required Discharge Head [ Pressure required at destination + Static head
(mlc)
42.91
(mlc)
32.51
(mlc)
50.00
oil storage tank) ( Re fe r AN NE X - III)
required + Friction loss in piping ] III. TOTAL DEVELOPED HEAD :
1
Total Developed Head [ Required Discharge head - Available Suction head ]
2
Selected Total Develoed Head
II AVAILABLE NPSH CALCULATION
1
Available pressure
(mlc)
10.65
2
Static Head
(mlc)
0 .2 0
(Atmospheric Pressure : 1.01325 bar a ) ( Assumed min. su bmergen ce in the tank)
3
P ip in g f ric tio n l os s in s uc ti on li ne
( ml c)
0 .0 0
( No t a pp li ca bl e)
4
Vapour pressure of fuel oil at operating temperature
(mlc)
0.20
(Preliminary data)
5
P re ss ur e d ro p i n s uct io n s tr ai ne r
( mlc )
0 .4 5
( Pr eli min ar y d at a)
Available NPSH [ Atmos pher ic pr es sure + S tatic he ad in the tank -
(mlc )
10.20
6
Vapour pressure of fuel oil at operating temperature - Pressure drop in Suction Strainer) III
1
PUMP DESIGN PARAMETERS
Pump type
Positive displacement, Singl Screw, Vertical tank mounted type
2
Rated Capacity per pump
(m³ / h)
5
3 Selected Total Developed Head for pump
(mlc)
50.00
4
Available NPSH
(mlc)
10.20
5
Pump efficiency
%
40
kW
1.65
6 Estimated Shaft power
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
FICHTNER India
(Vendor to confirm)
Page : 10 of 11
WCPPL
Calculation HFO / DO Drain Pump Sizing
300 MW Combined Cycle Power Plant
ANNEX – V : FORWARDING AREA HFO/DO DRAIN PUMP SIZING CALCULATIONS 1
Total Number of pumps
1
2
Number of operating pumps
1
3
Total flow per pump
(m³ / h)
4
Density of drain oil
(kg / m )
5
Capacity of the drain oil tank
I
HEAD CALCULATION
3
3
m
5 970 2
I. SUCTION SIDE :
1
Available pressure
(mlc)
10.65
(Atmospheric Pressure : 1.01325 bar a )
2
Stati c Head
(ml c)
0.20
(Assumed min.submergence in the tank)
3
Friction loss in the piping
(mlc)
0.00
(Not applicable)
4
Pr es su re dr op i n s uct ion s tr ai ner
( ml c)
0 .4 5
(P rel im in ar y dat a)
Available Suction Head [ Atmospheric pressure + Static head in the tank -
(mlc)
10.40
1 Pressure required at destination
(mlc)
10.65
2 Static head required
(mlc)
11.635 (From GA of untreated Heavy fuel
5
Pressure drop in suction strainer ] II. DISCHARGE SIDE :
(Atmospheric Pressure : 1.01325 bar a )
oil storage tank) 3 Fr ic ti on l os s i n t he pi pi ng
( ml c)
37 .0 7
( Ref er AN NEX - III)
4 Required Discharge Head [ Pressure required at destination + Static head
(mlc)
59.35
(mlc)
48.95
(mlc)
50.00
1 Available pressure
(mlc)
10.65
(Atmospheric Pressure : 1.01325 bar a )
2 Stat ic Head
(ml c)
0.20
(Assumed min. submergence in t he
required + Friction loss in piping ] III. TOTAL DEVELOPED HEAD :
1 Total Developed Head [ Required Discharge head - Available Suction head ] 2 Selected Total Developed Head II AVAILABLE NPSH CALCULATION
tank) 3 P ipi ng f ri ct io n l os s i n su ct ion l in e
( ml c)
0. 00
( No t ap pl ic abl e)
4 Vapour pressure of fuel oil at operating temperature
(mlc)
0.20
(Preliminary data)
5
( ml c)
0 .4 5
(P rel im in ar y dat a)
(mlc)
10.20
Pr es su re dr op i n s uct ion s tr ai ner
6 Available NPSH [ Atmospheric pressure + S tat ic head i n the tank Vapour pressure of fuel oil at operating temperature - Pressure drop in ] Suction Strainer) III
PUMP DESIGN PARAMETERS
1
Pump type
2
Rated Capacity per pump
(m³ / h)
5
3
Selected Total Developed Head for pump
(mlc)
50.00
4
Available NPSH
(mlc)
10.20
5
Pump efficiency
%
40
6
Estimated Shaft power
kW
1.65
Doc. No. 7856-ME-DSN-131-004, Rev. A Calculation_drain pump_A
Positive displacement, Singl Screw, Vertical tank mounted type
FICHTNER India
(Vendor to confirm)
Page : 11 of 11
