Customer Training
Jaypee Nigrie Super Thermal
Power Plant
By G Murugesan & Manoj Ayodhyawasi
Date:31-05-2013
Boiler Circulating Pump
Boiler Circulating Pump (BCP)
Contents
1. Introduction
2. Technical Features
3. Operation and Maintenance
Boiler Circulating Pump (BCP)
PURPOSE
BCP is required for start-up of the supercritical boiler. The
recirculating system is installed to recover heat during start-up
by circulating the water not evaporated in the furnace back to
the economiser inlet, thereby reducing the start-up time.
BCP operates in conjunction with boiler feed water pump.
The BCP is used during start-up and at low loads to provide
adequate mass flow through the furnace water wall tubes.
4
Boiler Circulating Pump (BCP)
Functions of startup system
WS separate the water from furnace outlet steam during start-up
and accumulates at WSDT.
The accumulated boiler water shall be re- circulated across the
furnace by BCP for furnace wall protection and heat recovery.
WSDT level shall be controlled and excess water will be dumped
into condenser through WDC valves.
5
Boiler Circulating Pump (BCP)
Location and use of BCP in SC Boilers
Boiler Circulating Pump (BCP)
Flow diagram of Super critical plant
Boiler Circulating Pump (BCP)
P&ID
8
Boiler Circulating Pump (BCP)
P&ID
9
2. Technical Features
Boiler Circulating Pump (BCP)
SELECTION CRITERIA
BCP is selected for the following operational conditions :
During start-up main steam flow is 5% of the BMCR main
steam flow for the minimum stable operation of BFP.
Maximum wet operation of normally 25-35% BMCR flow.
Cold clean-up of 30% of the BMCR flow.
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Boiler Circulating Pump (BCP)
BCP Technical Data for Jaypee Project
Designation - Glandless Circulating Pump
Service - Boiler Circulation Pump
Supplier - Torishima Pump Manufacturing Company
Limited, Japan
Number per unit - One
Design Temp - Pump 359 deg C
- Motor 90 deg C
Design Pressure – 28.4 MPa
Operating Temp – 287.3 deg C
Capacity - 890 m3/hr
Total Head - 110 m
Boiler Circulating Pump (BCP)
GENERAL ARRANGEMENT
Boiler Circulating Pump (BCP)
Torishima BCP : Features - Benefits
• Maintenance free and high
reliability
Simple Structure
• Easy start-up and shut-down
operation.
Direct connection • No foundation work and
of the pump and easy installation
pipeline
Vertical
suspension type • Less space
design
Pull-out system • Easy installation, overhaul
design and inspection work.
Boiler Circulating Pump (BCP)
Glandless • No Seal / No Leakage
Highly-
durable water- • Maintenance free for the bearings
lubricated
bearings
Variable type
• Volute, annular or spherical design
of casings
Boiler Circulating Pump (BCP)
Wet-type coil • High efficiency and
reliability
motor
• Only low pressure cooling
Effective motor water is required (High
cooling circuit pressure cooling water is
not needed)
Boiler Circulating Pump (BCP)
Arrangement and Constructional Features
BCP is a vertical, centrifugal and wet motor Pump.
The pump is designed to be suspended from the suction nozzle
with the motor unit bolted to the underside of the pump case.
The motor is a wet motor – it will be subjected to the same fluid
pressure that the pump handles.
It is a glandless (seal less) pump motor unit with pump and
motor being integrated in a pressure-tight casing.
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Boiler Circulating Pump (BCP)
Arrangement and Constructional Features
The cooling of the motor and the bearings is achieved by means
of an internal water circulating system with external motor
cooler.
In case of emergency, if motor temp is rising and alarm is
triggered then it will be cooled down temporarily by purge water
from purge cooler. Purge cooler is provided for emergency
purpose and initial filling of BCP.
The glandless design (no shaft seal) makes this pump best suited
for pumping of high temperature and high pressure liquids
without any leakage at all. 18
Boiler Circulating Pump (BCP)
IMPELLER
PUMP CASING
SHAFT
DIFFUSER
HEAT BARRIER
STUD BOLT
PLAIN BEARING
(UPPER)
MOTOR WINDING
MOTOR CASING BEARING BRACKET
MOTOR COOLER
STATOR
THRUST BEARING PLATE
ROTOR
PLAIN BEARING (LOWER)
THRUST BEARING
SEGMENT (UPPER)
THRUST BEARING SEGMENT
(LOWER)
THRUST BEARING CASE
FILTER
Boiler Circulating Pump (BCP)
Nozzle
Casing
This vertical pump is suspended in a pipe
line without any outside supports. Heat barrier
No anchorage point in the piping system.
During overhauls, the pump casing can
remain in the pipe line.
Motor
The motor unit, together with the heat
barrier and the impeller, can be removed
from the casing after unscrewing the Tie
bolts.
Bearings
Boiler Circulating Pump (BCP)
BEARINGS
The shaft is supported by the two
self-lubricated plain bearings.
The axial thrust is also supported by a
self-lubricated thrust bearing.
Bearings
Thrust Bearing
Boiler Circulating Pump (BCP)
NOZZLE ORIENTATION
Nozzle
Suction nozzle is arranged axially
(end suction) and the discharge nozzle
radially.
The nozzle can be provided with
welding stub ends.
Boiler Circulating Pump (BCP)
HEAT BARRIER
A heat barrier is provided between Heat
the pump and the motor. barrier
The heat barrier prevent heat transfer
from the hot pump to the cold motor.
The heat barrier protect the motor
winding insulation.
Boiler Circulating Pump (BCP)
MOTOR
The motor is filled by the water.
The HP cooling water inside the motor is
circulated by a thrust bearing plate.
The motor heat is transmitted to the LP
cooling water in the motor cooler. Stator
Rotor
Motor cooler
Thrust bearing plate
3. Operation and Maintenance
Contents
3.1. Technical Data
3.2 Commissioning and Start-Up
3.3 Supervision during operation
3.4 Protection and interlock
3.5 Cause and Remedy of Operational
Trouble
3.1 Technical data
Pump set
- Pump name Boiler Circulating Pump
- Number of sets per unit 1 set/unit
- Designation Glandless Circulating Pump
- Design pressure 289.6 kg/sq.cm g
- Design temperature
- Pump 359 deg. C
- Motor 90 deg. C
- Hydrostatic test pressure 434.4 kg/sq.cm g
3.1 Technical data contd…
Pump
- Type Vertical Glandless Centrifugal Pump
- Fluid pumped Boiler water
- Operating temperature 287.3deg. C
- Capacity 890 m3/h
- Total head 110 m
- NPSH req. 7m
- Suction nozzle 372mm
- Discharge nozzle 302mm
3.1 Technical data contd…
Motor
- Type HLV55/4EV38-335 Wet motor
- Rating 380 kW
- Speed 1,465 rpm
- Frequency 50 Hz
- Voltage 3,300 V
- Current 92.1 A
- Starting current 599 A
- Insulation of motor winding PE 2/PA
(cross link polyethylene/polyamide)
- Motor normal temp. 50 deg. C (at upper motor cavity)
- Motor alarm temp. 60 deg. C (at upper motor cavity)
- Motor trip temp. 65 deg. C (at upper motor cavity)
3.1 Technical data contd… (4)
LP Cooling Water
Heat Barrier
- Cooling water quantity required 1.8 M3/hr
- Design inlet temperature 36 deg. C
- Emergency cooling water required 1.08 M3/hr
Motor Cooler
- Max capacity of heat to be eliminated 158,000 kJ/h
- Cooling water quantity required 9.48 M3/hr.
- Design inlet temperature 36 deg. C
Contents
3.1. Technical Data
3.2 Commissioning and Start-Up
3.3 Supervision during operation
3.4 Protection and interlock
3.5 Cause and Remedy of Operational
Trouble
3.2.1 BCP and its system
3.2.1 BCP Purge water system flushing
3.2.2 Priming and venting
① Open V1 and close V2, then flush the purge line ② Close V1,V5
③ Open V2 and V4 ④ Open valve3
⑤ Adjust V3 : Flow rate from valve4 is max. 0.3 Cu.M/hr
⑥ Close V4 ⑦ Open V6
⑧ Open V5 slowly
V6
⑨ After confirming that the
water from valve 6 is clean,
close valve 6 and valve 5
⑩ Disconnect the
V5 V3 V2 flex pipe and flush
the cooling water
line
V4 V1
3.2.3 Pre Operational Check Items
① To confirm water filling
② To measure insulation resistance
③ To confirm correct direction
④ To monitor operational check items
- Motor cavity Temperature
- Cooling water flow
`
- Motor protection cutout switches
- Motor current
3.2.3 Pre Operational Check Items contd …
⑤ To confirm quantity of LP cooling water ⑥ To confirm HP cooling water temp: Max. 60 deg. C
⑦ To check water level in WSDT ⑧ To ensure complete motor flushing
⑨ To assure pressure tight seals
LP : auxiliary cooling water
HP : motor inside cooling water
Need to check Item ⑤, ⑥, ⑦ in
routine starts !
Contents
3.1. Technical Data
3.2 Commissioning and Start-Up
3.3 Supervision during operation
3.4 Protection and interlock
3.5 Cause and Remedy of Operational
Trouble
3.3.1. Supervision during operation(Normal Operation)
(1) WSDT level >4M (2) HP Cooling water temperature ≦ 65 deg. C
(6) Motor current at switch gear room (5) LP Cooling water outlet temperature
≦ 92.10 A
≦40 deg. C for Motor cooler
≦38 deg. C for Heat barrier outlet
(4) LP Cooling water flow rate
for Heat barrier is adequate
(7) Smooth
running or not
(3) LP Cooling water flow rate for motor
Cooler is adequate
3.3.2 Supervision during operation(Pump stop)
(2) HP Cooling water temperature ≦ 65 deg. C
(2) LP Cooling water outlet temperature
≦40 deg. C for Motor cooler
≦38 deg. C for Heat barrier outlet
(4) LP Cooling water flow rate
For Heat barrier is adequate
(3) ) LP Cooling water flow rate
for motor Cooler is adequate
Contents
3.1. Technical Data
3.2 Commissioning and Start-Up
3.3 Supervision during operation
3.4 Protection and interlock
3.5 Cause and Remedy of Operational
Trouble
3.4.1 Logic Block diagram for BCP
Contents
3.1. Technical Data
3.2 Commissioning and Start-Up
3.3 Supervision during operation
3.4 Protection and interlock
3.5 Cause and Remedy of Operational
Trouble
Cause and Remedy of Operational Trouble shooting
No. Problem Reason Remedy
1 Insufficient LP Examine LP cooling water Open valve fully. Ensure the
cooling water flow rate. LP cooling water flow.
2 LP cooling water Examine LP cooling water Ensure LP cooling water
temp. high temp. temp.
3 Malfunction of HP Examine HP cooling water Flushing and cleaning of HP
cooling water circuit inlet / motor cavity cooling water piping and filter.
temperature
4 Leakage from HP Visual and liquid dye Repair by welding.
cooling piping penetrate examination.
6 Fouling of motor Examine motor cooler inlet / Cleaning of motor cooler tube.
cooler tube motor cavity temperature
Inspect shell inside via hand-
hole.
