TURBINE DRIVEN BOILER FEED PUMP -ABC OF THERMAL POWER PLANT

Check clearances of Thrust bearing of BFP and Booster Pump-Feller Gauge / Dial Gauge.

Ensure specified clearances between guide slips & key (at the bottom of pump casing), and then 

welding of key block on base frame-Vernier/ Tape.

Hydraulic testing of coolers (waterside) - Pressure Gauge. should be calibrated

Note: Coolers if already hydro tested at manufacturing works and test certificates available, need not be hydro tested at site.

Completion of welding and NDE of welds of following lines:

a.   

       a       BFP discharge line.

.   b. BFP suction line.

c

.    c. Booster Pump Suction line.

d. 

     d.  Booster Pump discharge line

Ensure pre heat treatment and post-weld heat-treatment of weld

Ensure that the entire pipeline is supported by permanent supports before making the last four joints 

of  BOOSTER PUMP & MAIN PUMP suction and discharge.

Ensure that the piping doesn’t exercise any pull on pump nozzles. This is extremely important in the 

case of BFP suction & discharge, which are welded joints). This is true for any nay major or minor 

rotating machine . That means final connection to be done when  piping is in free float. This can be 

achieved  if all the pipelines are erected as per drawing and permanent supports are adjusted as per 

drawing value. In fact in BFP we check that pipe lines can be moved by hand only without any 

difficulty. Same philosophy is applicable for BOOSTER PUMP also . However BOOSTER PUMP 

connection is through fastners only therefore can be manipulated easily so not critical as MAIN 

PUMP. Instances are available that after final connection alignment was disturbed so much that 

pipeline was cut and re-weld after necessary correction. This area is major bone of contention 

between piping engineer and pump engineer.

Distances and alignment readings between coupling half faces of Booster Pump & Gear box, Gear

box & Drive turbine shaft, Drive turbine shaft & BFP after completing pipe connections.

Welding of key block on base frame after ensuring specified clearance between guide slips & key (At

the bottom of pump casing.

Small bore pipeline connection of oil lines of drive turbine , Cooler lines oil and water , Sealing lines

of pumps  Govering system installation and other steam lines to be connected and completed. Final

connection to be done after ensuring , oil flushing ,steam blowing ,water flushing ,chemical cleaning

etc is completed as per requirement under laid down procedure .Any short cuts will bring problems

afterwards .That is during stabilisation of units.

Necessary instrumentation on oil tank ,oil lines , bearings ,gear boxes and pumps are calibrated and

installed  as per drawing. Specially Turbovisory instruments for drive turbine , governing control

system are installed carefully.

PROCESS FOR PRE COMMISSIONING AND COMMISSIONING 

P.S If  you are looking to earn few legitimate extra money from the comfort of your home then please click on the link given below

LINK 1 - PLEASE CLICK HERE 
LINK 2 - PLEASE CLICK HERE

to know about  PTC please read my other blog "common man"

continued to part -iii

TURBINE DRIVEN BOILER FEED PUMP EREC. &COMMNG -ABC OF THERMAL POWER PLANT

As  stated in earlier posts there are three Boiler Feed Pumps (3x 50%) in a thermal power station of 500MW and above. 2x50% turbine driven BFP ( normally working when unit is running above certain load ) and other is 1x50 % MDBFP  which usually runs during start up .

We have already explained in last few blogs about erection and commissioning of MDBFP . For TDBFP pumps are same whether it is booster pump or main pump. Instead of MOTOR driven we have variable speed turbine with disconnecting coupling both sides . In this blog we will discuss only the turbine as pumps are similar.

 Technical data of Turbine

a.  Maximum output                                         7575  KW

b.  Design rating 

        (Economical rating)                                  5732 KW

c.  Speed                                                            5275 RPM

d.  Speed range                                                  1494-5750 RPM

e.  Initial Steam Pressure                                   6.33 ata.

f. Initial steam Temperature                              289.6 0 C.

g.  Exhaust pressure                                           0.1064 ata.

Oil System

a.  Lube oil pump                                              2 Nos

b.  Emergency Oil pump                                   1 No.

c.  Jacking Oil Pump                                         1 No.

d. Oil vapour extractor fans                              2 Nos

PROCESS  : ERECTION CHECK

Foundation checking of elevation ,plan that is different pocket holes and other measurable items as per given approved drawing . This the protocol for taking foundation from civil vendor for erection  purpose .(elevation within+5mm/-10mm). 

Check that depth and verticality of each pocket is OK. Checking to be done by water level /dumpy level/ total station.

Distance from fixed reference axis e.g. A-row, B-row Columns.  (1mm / metre,  5mm Max.)- Establishing centre line as given in the drawing by putting distances from fixed point . This can be done by measuring tapes or by total stations .

Marking of equivalent axes on foundation. Plumb Bob / total station.

Fitting of half couplings to all equipment after ensuring corresponding fits.  For taper coupling, ensure around 80% contact between shaft & coupling.

Blue matching the top surface of foundation frame with corresponding bottom surfaces of equipment with around 80% contact.

Positioning and alignment of all equipment on the foundation. Measure distance between coupling half faces of following equipments by Vernier / Micrometer / Tape

            Booster Pump and Gearbox

            Gearbox and Drive turbine

            Drive turbine and BFP.

Grouting of Foundation Bolts. Check that nut has full contact with foundation frame after tightening.

Leveling and alignment of equipment  by jack bolts (within 0.1 mm / M). Dumpy / Precision Spirit level) and different thickness packer plates.

Foundation frame grouting. Now a days grouting is done with ready mix concrete of 25kg bags main supplier is ACC, PAGEL ,FOXROC etc. This is a specialised job it is advisable to do concreting in presence of suppliers representative to avoid any complicacy afterwards. Please insist on test certificate and cube testing on one day and three day sample. This may delay the process however by passing any of the test may complicate the situation afterwards. Major checks of equipment are already told during my earlier blog. Please go through it.

Alignment (lateral and angular) between booster pump & gearbox, gearbox & Drive turbine shaft, Drive turbine shaft & BFP, Measure distances between coupling flanges. This is done without any pipe connection ( water line ,oil line and steam line ). This is pre final reading and after doing final connection final reading to be taken. However during course of erection this reading is checked to find the effect of connection. Dial Gauge/Micrometer.

P.S If  you are looking to earn few legitimate extra money from the comfort of your home then please click on the link given below

LINK 1 - PLEASE CLICK HERE 
LINK 2 - PLEASE CLICK HERE

to know about  PTC please read my other blog "common man"

Continued  to part –ii ( TDBFP)

BOILER FEED PUMP ERECTION AND COMMISSIONING FINAL PART-ABC OF THERMAL POWER PLANT

TYPICAL INTERLOCK & PROTECTION REQUIRED FOR BFP COMMISSIONING

Ensure completion, installation and readiness of all instrumentation works, as per instrumentation

schedule, on BFP/ Booster pump/ Motor/ Hydraulic coupling/ de- aerator.                         

                                               

Calibration, setting and testing of primary instruments.                

                  

 Pressure gauges/ switches/ transmitters calibration and installation and wiring up to JB.                              

 Temp gauges/ switches/ transmitters calibration and installation up to JB.                           

                  

 Level gauges/ switches/ transmitters.                  

               

Limit switches.                 

Installation of JBs, cabling & termination in local and control room.                          

Readiness of control supply to Panels:                                                                  

Availability of LT & HT supplies   and readiness of electrical protection instruments.         

Readiness of mechanical system.                                                                                            

 Oil system                         

 De=aerator                       

Compressed air system.               ( Compressed air is required for pneumatic valve operation.     

Charging and testing of panels.                 

Commissioning of motorized  valves,  actuators & pneumatic re circulation valve.                              

Checking of Interlocks, protections & Alarms:                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    .                              

                (i)   Calibration of speed control device like scope tube /thyrister control etc                       

                (ii)  Oil pressure low                       

                (iii)  Suction valve open                                

                (iv)  De-aerator level low                             

                (v)   Feed pump suction/ discharge temperature high.                   

                (vi)  Balancing leak off pressure. high                     

                (vii)  Re circulation valve open                    

                viii)  Bearings vibrations high (wherever provided)                          

                ix)   Remote/ local tripping          

                TRIAL RUN OF HYDRAULIC COUPLING

               

               

Readiness of lubrication oil & working oil coolers and availability of cooling water.

Charge lubrication  oil and working oil coolers.

Checking of HC interlocks & protections

Ensure alignment of Hydraulic coupling with BFP motor.

Ensure proper  earthing of Hydraulic coupling.

Check oil level in hydraulic coupling sump.

Start AOP and monitor lubrication oil header pressure.

Start trial run of Hydraulic coupling.

Check regulating oil pressure and set, if required.

Monitor all parameters of hydraulic coupling; Gauges are available /mounted on the equipment

                   I.   Lubrication oil and Regulating oil pressure.

                   ii.   Motor current.

                   iii.  Hydraulic coupling bearings temperatures.

                   iv.  Lubrication oil temp at L. O. cooler inlet and outlet.

                   v.   Working oil temp at W.O. cooler inlet and outlet.

                   vi.  Motor winding temps.        

TRIAL RUN OF BFP

               

               

1      Ensure free rotation of BFP by hand before coupling.                                                                                                                               

2      Ensure completion of alignment:                                                                                                                              

                     I.    Motor & Booster pump

                     ii.    Motor & hydraulic coupling.

                     iii.   Hydraulic coupling & BFP

Special attention to be given on pipe line final connection.Pipes to be ensured as free body  through

hanger adjustment.  No tension on pipes is permitted otherwise alignment  will be disturbed.

3              Flushing of mechanical seal cooling water lines for BP as well as BFP & Mechanical seal water

cooler cooling water lines.

4              Optimisation of oil flow through bearings by using orifice plates

5              Running of AOP

6              Charging of all system:  

                (i)  Lubrication oil/ working oil coolers

                (ii)  Seal water coolers

                (iii) Suction valve opening 

                (iv)  Re circulation valve (Isolation  valve) opening

                (v)  Charging of C&I local panels

7              Fill de=aerator and maintain normal level.  

 8              Interlocks & protections checking.

9              Start BFP.

10           Monitor all parameters of BFP and motor;

                    I.    Current

                    ii.    BFP suction pressure.

                    iii.   BFP discharge pressure.

                    iv.   Balancing leak off pressure.

                    v.    De-aerator level.

                    vi.   BFP suction/ discharge Differential Temperature.

                    vii.   Lubrication oil/ working oil pressures and temps.

                    viii.  Booster pump/ BFP/ Motor/ Hydraulic Coupling bearings and drain oil temps. 

                    ix.   Cooling water temps.

                    x.    Seal water/ seal water coolers temps.

                    xi.    Motor winding temps.

                    xii.   Bearing vibrations.

BOILER FEED PUMP ERECTION AND COMMISSIONING PART-VI ABC OF THERMAL POWER PLANT

FINAL COMMISSIONING OF BOILER FEED PUMP ( mdbfp)

Till my last dispatch we have discussed erection and commissioning of Boiler Feed pump including oil flushing of lubrication oil lines ,acid cleaning of the same , hydraulic test of coolers and other integral pipelines. Now we will discuss about Boiler feed pump commissioning as a whole. BFP( MDBFP) is one of the first major equipment need to be commissioned before Boiler light up.

Commissioning includes checking of following activities completion as per drawing and quality plan.

1              Erection completion of feed water lines.

2              Instrumentation stub parts completion.

3              Completion of Alkali/ detergent flushing of feed water system, as well as condensate system and heaters drip system.

4              Cleaning and normalisation of deaerator and feed lines

5              Checking & setting of hangers and supports of feed water lines including BFP suction lines, recirculation lines.

6              Deaerator filling with DM water.

7              Final flushing of the suction lines of Booster Pump & BFP .

Readiness of cooling water system

1 Erection completion of cooling water lines of,                                                                                                                                                                                                                                                                                                                                                                                                    

BFP Motor

                Lubrication  oil coolers and working oil coolers

                Seal water coolers of BP & BFP

2              Commissioning  of the motorised actuators of motor cooling water valve..

3              Checking & setting of hangers & supports of CW lines of CW system and motor cooler.

4              Availability & readiness of cooling water/ system.

5              Flushing of all cooling water lines of CW system and motor cooler.

Completion of  ACW  system and heat exchangers ,Pumps, tanks  ,pipelines with instrumentation.

Electrical and C&I work completion  of Feed Pump , Feed station , control valves ,actuators etc.

1              Meggering of BFP motor

2              Availability of HT supply

3              Ensure proper earthing of BFP motor and instruments panel..

4              Completion of instrumentation (bearing oil press & temp) impulse piping and mounting of

press/ temp gauges, and winding, temp RTDs

5              Filling of Hydraulic coupling sump with fresh oil after oil flushing & cleaning of sump

6              Oil pressure optimization  at motor bearings.

7              Ensure de-coupling of motor with booster pump and hyd. Coupling.

8              Ensure free rotation of motor by hand.

9              Checking of BFP motor protections and CW valve interlock.

10           Charging of CW system and lubrication  oil cooler.

11           Bumping of motor and checking DOR

12           Trial run of BFP motor

13           Monitoring of motor parameters.

                   I.    Motor current and voltage.

                   ii.   Motor winding temperatures.

                   iii.  Bearing temperatures.

Continued to concluding part

BOILER FEED PUMP ERECTION AND COMMISSIONING PART-V ABC OF THERMAL POWER PLANT

Oil pipelines are reassembled after acid cleaning is over.

Oil tank and duplex filters are clean.

Oil tank is filled to the required level with recommended oil. Oil should be filled through filter

/centrifuge. Oils of different quality / make should never be mixed. Follow OEM

Recommendation.

Oil pipelines are disconnected from the bearings. The bearings are bypassed by temporarily

interconnecting the inlet and outlet lines of bearings using temporary loops.

Oil lines are properly supported and all temporary supports are cut and removed.

Temporary line filter of stainless steel mesh is provided in the return line before entry to the tank to

avoid entry of dirt into MOT of Hydraulic coupling.

Working oil lines to working oil coolers disconnected at hydraulic coupling end and temporary loops

made as shown in the flushing scheme.

Temporary connections, preferably of transparent hose which can withstand temperature as high as

80⁰ C, are made across the bearings.

Portable centrifuge / electrostatic filtration unit is connected to the MOT of the Hydraulic coupling.

Suction of the unit is connected to the drain of MOT of Hydraulic coupling through suitable hose and  the 

discharge is left inside the Hydraulic Coupling tank through inspection cover.

Required instruments such as pressure and temperature gauges are calibrated and mounted in the

system.

Temperature of 65-75⁰C to be reached during oil flushing through centrifuge heaters.

With MOT of Hydraulic tank already filled with recommended oil, AOP is bump started to check the

direction of rotation of the pump.

After ensuring correct direction of rotation the AOP is run continuously and the system is filled

gradually.

Oil level in the tank is watched till oil flow is established throughout the system. Oil is topped up, if

required.

The system is checked for oil leakages and the leakages, if any, are attended.

Temperature of oil is raised to 65-70 deg Celsius by using the heaters of centrifuge or by external

heaters.

After attaining the elevated oil temperature, heater is switched off and cooling water is admitted in

the cooler to suddenly bring down the oil temperature to get an effect of thermal shock. Oil pipelines

are also tapped with wooden hammers during the period of thermal shock.

Oil temperature is again raised and thermal shock is given. Thermal shocks are repeated till oil

flushing is declared complete as per completion criteria.

The working oil and lub oil circuits are flushed separately by making suitable temporary connections.

Flushing of lub oil circuit is done in sub stages by grouping lines of two to three bearings ( to be

decided at site ) by suitable isolation of lub oil supply lines to other bearings to have adequate

velocity in the pipelines for effective flushing .

The filters are cleaned whenever there is an increase in differential pressure across the filter beyond

0.5 kg/cm² over the normal value. 

Periodicity of oil sampling and filter inspection is mutually decided at site.

Oil flushing of oil lines bypassing the bearings is declared complete based on completion criteria.

Hydraulic test of the pipelines is carried out at a pressure 1.5 times the working pressure with the

help of an external pump or the AOP itself. There should be NO leakage.

Temporary bypass connections / blanks / dummies / are removed and the pipeline connections with

the bearings are normalized.

Flushing of lub oil circuit with bearings included in the flushing circuit is started.

Flushing through bearings is declared complete based on completion criteria.

The oil used for flushing is drained and kept in safe custody. This oil can be used for flushing in

other units if the oil quality is found suitable. While using this used oil for flushing in other units,

filling should be done through centrifuge.

All the bearings are inspected and cleaned.

Fresh oil is filled in the system. Oil pump is run, flow through each bearing adjusted and flow of

return oil through each bearing ensured.

COMPLETION CRITERIA The flushed components are considered clean when the DP across the filter stabilizes and does not rise more than 0.2 to 0.3 ksc over the normal value after eight hours of continuous flushing. Also there should be NO deposition of hard particles in oil filters. Mechanical impurities ( through 0.45 micron filter ) and moisture content in the sample collected from flushing oil should be each less than 100 ppm in three consecutive samples taken at intervals of four hours. Continued to last part BFP commissioning

P.S If  you are looking to earn few legitimate extra money from the comfort of your home then please click on the link given below

LINK 1 - PLEASE CLICK HERE 
LINK 2 - PLEASE CLICK HERE