Boiler Operation (2)

Lucky cement Limited Pezu plant

Muhammad Aamir Hayat

Standard operating procedure

For

Boiler & Steam Turbine

Lucky cement Limited



Standard Operating Procedure of Boiler and Turbine of

Waste Heat Recovery Unit

Table of Contents

Chapter 01 boiler 1

1.1 Definition of Boiler 1

1.2 Working Principle of Boiler 1

1.3 Monitoring and tuning up of the boiler 1

1.4 Normal Operation of the boiler 2

1.5 Necessary Step before start up of Boiler 3

1.6 Damper Opening: (cold state) 3

1.7 Damper Opening (Hot State) 4

1.8 Shut Down 5

1.9 Blow Downs 6

1.10 Maintenance of the boiler 7

Chapter 02 Steam Turbine 9

2.1 Turbine Start Up and Operation 9

2.2 Before turbine start up 9

2.3 Starting of Turbine 11

2.4 Shutdown 12

2.5 Operation maintenance and downtime maintenance 13

2.6 Synchronization Process 13



Chapter 01 Boiler

1.1 Definition of Boiler

Steam boiler or simply a boiler is basically a closed vessel into which water is heated until the

water is converted into steam at required pressure. This is most basic definition of boiler.

1.2 Working Principle of Boiler

The basic working principle of boiler is very simple and easy to understand. The boiler is

essentially a closed vessel inside which water is stored. Fuel (generally coal) is bunt in a furnace and hot

gasses are produced. These hot gasses come in contact with water vessel where the heat of these hot

gases transfer to the water and consequently steam is produced in the boiler. Then this steam is piped

to the turbine of thermal power plant. There are many different types of boiler utilized for different

purposes like running a production unit, sanitizing some area, sterilizing equipment, to warm up the

surroundings etc.

1.3Monitoring and tuning up of the boiler:

The operating conditions of the waste heat boiler are directly related with that of the kiln. To

ensure the stability of the operating parameters and the highest safety of the operation, the close

communication with the kiln operators is extremely necessary for the best coordination; meanwhile, the

change of the boiler operating parameters, and the operating conditions shall be closely monitored and

analyzed for timely tuning and adjustment.

During the operation, the main purpose for the monitoring and tuning is:

Under the normal kiln operating conditions, to tune up the system to keep the normal operation and

maintain the normal pressure of the medium, maintain the normal water level by evenly feeding water

to the boiler to ensure the steam quality, and ensure the normal operation of the ash handling system.

1. Precaution for the boiler operation:

I. When the boiler is operating, pay attention to the steam pressure, steam temperature,

drum level, water flow, feed water temperature and pressure, the exhaust gas temperature

at boiler inlet, furnace minus pressure etc. In case there is a change in the exhaust gas flow

and temperature at boiler inlet but no effective result after tuning up, timely

communication is needed with the related department for an adjustment of inlet gas

temperature in order to ensure the boiler safe operation and the stable parameters of the

boiler.

II. Walk down inspection: In order to ensure the safe operation, at least 4 walk down

inspections shall be carried out for each operation shift. The items included in the

inspections are: all the equipment in the boiler building; check of the boiler casing for any

damage and air leak of the manholes; check of all the valves for abnormality; check of all the



water level gauges, pressure gauges, temperature gauges for abnormality, check of all the

sections and portions of the heating surfaces for soot deposition, wear and tear and check

of the boiler flue gas temperature.

III. Continuous recording on the logs. Once per hour logging shall be carried out. The purpose of

recording and logging is to analyze the operation condition and overall regularity of loading

alteration of the entire systems for better and reasonable operation.

IV. The regular sampling on the boiler feed water, boiler water, blow down water, steam and

produced water shall be carried out for chemical analysis to achieve the goal for economical

operation.

V. Based on the water quality and the chemical examination. The regular blow down of the

boiler convection tubing banks will be executed. The amount of blow down water shall be

determined based on the chemical examination result

VI. Feed water samples shall be inspected regularly to ensure the feed water quality.

VII. Regular and rules for shift alternation shall be strictly followed and the clear records shall be

kept on the daily logs.

1.4 Normal Operation of the boiler:

During the normal operation of the boiler, the water level shall be maintained normal, the

pressure stable, and the steam temperature normal. The monitoring of all the equipment and

instruments shall be continued to ensure the safe operation.

1) Requirement for the feed water: the boiler feed water shall be de-mineralized and

the quality of the de-mineralized waster shall comply with the appropriate national

criteria on the water quality.

2) The boiler water shall be kept within 75 mm of normal level, however slight

fluctuation shall be considered as normal. If the water level stays fixed, it might

indicate a plugging, requiring a washout of the water level gauge

1.5 Necessary Step before start up of Boiler:

By field supervisor

Field supervisor should get a detailed round of Boiler Physically.

Inspection doors of Boiler should be properly closed.

Ensure that the level of the water in the steam drum is at half full.

Feed water and steam valves should be in proper working condition.



Dampers should be verified before start up of Boiler.]

Water level should be maintained at required level.

R-O plant operator should be informed for preparation.

Drain valve of steam line should be opened.

Air vent of steam drum should be opened.

Exhaust valve of steam should be opened.

Hammering device of SP boiler should be ready.

By operator

First of all drain, water and steam valve for required operational condition.

Feeding water to boiler by feed pump till half of steam drum.

Keep the boiler vents open until a heavy steam jet is flowing out (until a boiler pressure of about 1 bar is reached).

Co-operating with kiln operator about their required parameter and then opening dampers

accordingly.

1.6 Damper Opening: (cold state)

When the hot gases temperature at the cooler exhaust is at 150-200C then

10% inlet damper open

10% outlet damper open

90% by pass damper open

After 30 minutes

When temperature at cooler exhaust is at 200-250C then



80% by pass damper open

When the temperature at the super heater now reaches up to 400C then we take the boiler in line

because our steam temperature & pressure reaches 310-350C and 1.2MPa respectively





100% by pass damper closed

According to the careful estimation, opening of the damper with respect to time is enlisted

as under:

Sr.No Outlet Inlet Damper (%age) By Pass Damper (%age)

Hot Gas Temperature (C)

Time (min)

1 10 90 150-200 30

2 20 80 200-250 45

3 30 70 250-300 65

4 40 60 300-350 85

5 50 50 350-400 105

6 100 0 400-450 120

1.7 Damper Opening (Hot State):

When there is a stoppage for some hours, then the boiler still carries some temperature &

pressure and in that case how, the damper opening will be executed .It is given as

Sr.No Outlet Inlet Damper (%age) By Pass Damper (%age)

Hot Gas Temperature (C)

Time (min)

2 20 80 250 15

3 40 60 300 25

4 60 40 350 35

5 80 20 400 45

6 100 0 450 60

1.8 Shut Down:-

The boiler shutdown is depending on the kiln operation on one hand and the boiler operation

on the other hand. Boiler shutdown may proceed in three ways based on how long the shutdown shall

last: temporary shutdown, complete shutdown and emergency shutdown.

1. Temporary shutdown and complete shutdown may proceed in the following steps:

I. Open the by-pass flue, and close the inlet gas butterfly valve

II. Watch the water level and continue to make up for the feed water

III. Reduce the boiler pressure to the 0 , and then close the main steam stop valve.



2. Emergency shutdown:

One of the following situations calls for the emergency shutdown (the steps for the

emergency shutdown are similar to the temporary shutdown):

i. The water level of the boiler drops down beyond the lowest limit of the specified

level range;

ii. Water level continues to drop down despite the increased water feeding or other

necessary action for water filling;

iii. The water level of the boiler rises beyond the upper limit of the specified level

range;

iv. Feed water equipment is all in malfunction.

v. Failure of all the instruments such as the water level gauges, pressure gauges and

safety valves.

vi. Serious damage to the boiler walls, steel structure overheated purling the safe

operation of the boiler.

vii. Explosion or burning in the flue, severely threatening the safety of the boiler and

personal life.

viii. Kiln requires boiler emergency shutdown

ix. Other abnormality requires the emergency shutdown of the boiler because of the

safety limits are exceeded.

Whenever there is a shutdown taken, the drains of steam lines are opened but the water should

be there in the boiler so that shrinkage and other metallurgical effects can be avoided. Also the steam

drum is filled with water, Hence the rusting effect is avoided to a larger extent.

On the other hand, when there is a planned shut down and tubes are to be replaced, and then

boiler should be cooled down slowly under normal parameters. When the temperature goes down to

the required or optimum value (40-50C) then drains will be opened followed by the cutting of the tubes

for replacement.

1.9 Blow Downs:-

a. Regular blow down shall be carried out when the boiler is operated at a low load, at least

once per shift. In addition, more blow downs may be applied in consideration of the dosing

and the boiler water quality.

b. Before each blow down, the check with the piping and the valves for abnormal conditions

shall be conducted. Besides, the water level shall be adjusted to about 35 mm higher than



normal, and each blow down shall be controlled such that the water level drops down by

about 35 mm.

c. Neither long lever, nor hammer is allowed to forcedly open the valve or peen the valve to

prevent the dangers. When two or more than two boilers share the same blow down

header, the simultaneous blow downs for these boilers are strictly prohibited.

(They are installed on the headers and points)

Limitations:

4-5 tons water is wasted for blow downs.

Dozing:

To attain parameter standards in boiler

To avoid scaling, corrosion

To improve efficiency

For smooth turbine operation

Drum:

Ph sphate (5-20)

Alkalinity (OH +ve)

PH (10-12)

Hardness Removal Nil

To Remove O (.005)

For passivation of all boiler surfaces.

Drain valves are closed now

Auxiliary oil pump stops, now the turbine is ready to be synchronized with the power plant.

Oil Pressures:

Lubricating oil pressure = 0.30MPa

Control Oil Pressure = 0.9MPa

Oil Temperature Inlet = 40~50C



Oil Temperature Outlet= 35~45C

Oil temperature should not be less than 35C

Maintain De-Aerator Vacuum = -0.080MPa

Maintain Condenser Vacuum = -0.085~ -0.090MPa

Check vibrations of turbine front Bearing , turbine rear Bearing limits= 2~22m

Bearing Temperature should be 40~70 C

Axial displacement limits should be between (-0.3 ~ +0.3)

Condenser Hot level should be from (424 ~ 464mm)

1.10 Maintenance of the boiler

After 5-6 months of the boiler operation, the boiler should be down for maintenance.

(1) To clean off the deposits in the drum, headers of the boiler

(2) To clean off the soot on the heating surface.

(3) Inspection on the internal or external sections of the boiler, such as check of the welds

of the pressure parts and steel sheets for corrosion. Severe defects shall be subject to

immediate remedy action. If the suspicious defects are located but not impacting the

safe operation, records shall be taken for future reference.

(4) Check the induced draft fan for bearing abnormality, check the impeller and the casing

for wears and tears. The user shall keep sufficient spare parts for the impellers.

(5) Some portions of the boiler walls can be removed for thorough inspection, if necessary.

When the inspection locates the serious damage, the complete repair has to be carried

out before start up. All the findings from the inspection and the repairs after the

inspections shall be entered into the boiler safety technical logs.

(6) Preservation for the boiler out of service for a long time:

a. Water preservation: fill up the boiler with the treated water, and then boil up the

water to remove the air. Fully close all the doors and openings. Or fill up the boiler

with the de mineralized water of high alkalinity to prevent the corrosion. The

chemicals added into the de mineralized water usually are NaOH (2kg/m) or

NaPO (5 kg/m), and that added into the boiler water are NaOH (5 kg/m) or

NaPO (15-20 kg/m). This method is only for short time shutdown preservation

with the heating surfaces and the boiler walls properly dried.



b. Pressure preservation: After removal of deposits from inside the boiler, all the

valves shall be closed. Preservation solution is to be added up to the lowest point

of boiler outlet header. Heat up the boiler to create a pressure of 0.1-0.2MPa, and

then hold the pressure for 2-3 hours. After pressure is dropped down, the

preservation solution should be used again to fill up the boiler, and then keep the

pressure of 0.2MPa by using a hydraulic way. The preservation solution is

composed of caustic soda (100mg/L), phosphorus pent oxide (100mg/L), sodium

sulfate (250mg/L). During the preservation period, regular inspection for the

proper concentration of the solution is required. When the concentration of

sodium sulfate is found to be lower than 50mg/L, more of that chemical shall be

added to keep the specified concentration.

c. Nitrogen preservation(omitted)

When the boiler is down for a quite long time, the nitrogen preservation can be

applied.



Chapter 02 Steam Turbine

2.1 Turbine Start Up and Operation:

Start the main auxiliary oil pump for 30 minutes before the turbine starts. Condensate pump

and jet water pump start along with circulating water pump.

Reset turbine and ensure the both ESV are fully opened.

Open boiler stop valve from the headers

Open main stop valve of the turbine

Check steam temperature and pressure are normal.

Push Run button at 505 turbine control (turbine will start @ 600rpms limited)

600 rpm are maintained for 30 minutes

After 30 minutes, push ENTER + 1000+ ENTER=1000rpm

At 1000 rpm running time is 90 minutes.

Next Enter+2600+Enter, the rpm will reach 2600 rpm

After 20 minutes, Enter +3000+ Enter, the speed will increased up to 3000rpm.

Before Pushing to the RUN command ensure the DCS system RESET and ALLOW Start Up and

505 system RESET

Reset guarding system , slightly move up the handle of emergency sliding valve, set the pressure

of quick stop oil, turn clockwise start up control valve by 90(1839). Then start up oil pressure

will slowly rise at 0.85MPa. Where quick stop control valve should be twirled counter clockwise.

The quick stop oil pressure will slowly rise at 0.85MPa,and then start up control valve should be

twirled counter clockwise by 90 with a result that start up oil pressure should become lower

slowly and the closed quick stop valve opens gradually to full extent then

2.2 Before turbine start up:

1. Before the start the rigorous inspection must be carried out;

a. Check the systems of vapor , drainage system;

b. Inspect the instrument measuring point must be normal and right;

c. Be sure components should be intact, and rotational part is flexible, non-jam situation. The

fastening screws should be tightened. Turning devices to listen carefully to check the sound

without friction;



d. Check normal condition of condensing steam system.

e. Check the location of speed control system, the correctness of Emergency Trip throttle

position in a release.

2. Warm pipes and hydrophobic

a. Isolation valve open slightly so that the pressure to maintain the tube at about 0.25MPa.

heating pipes, the temperature rise rate of 5~ 10 C/min;

b. Tube wall temperature should arrive 130 ~ 140 C , in order to speed 0.25MPa/min pressure

riser to rise to the provisions of values.

When warm tube, the trap door should open as much as possible so that condensation water

can discharge, with the tube wall temperature and pressure rise, a gradual clearance of small

hydrophobic door to prevent substantial leakage of steam.

Warming tube Notes:

I. Must be strictly to prevent leakage of steam into the cylinder that can cause rotor

deformation;

II. The temperature of the various parts pipeline (such as flange and bolts, etc.) should

not different too much;

III. Wall temperature should not less than the corresponding saturation temperature

under the pressure.

At the same time, start circulating water pump, then water to the condenser space.

Start up condensation pumps and recirculation door, so that condensation water

between the exhaust and the condenser can cycle, at last start up the main exhaust

opening and the total exhaust device to warm tube.

3. Running the oil cycle and check it

4. Starting condensing steam system, check the vacuum system are in normal conditions.

5. Check the level of following items:

I. cooling tower water level = 2800mm

II. Jet water tank level = 1500mm

III. Oil tank level = 234mm

IV. De Aerator water level = 1600mm

Check all parameters and all drain valves should be opened.



2.3 Starting of Turbine

1. Start up disk car devices, keep status to listen to any disc friction sound

2. Wear Emergency throttle

3. Low speed warm up, when warm tube finished, close the trap door. When the vacuum up to

400 ~ 500mm Hg, become the slow gradual warm up, maintain speed at 600rpm around about

20 ~30 minutes. Pay attention to oil temperature that should be at 35 ~ 40 C, if it too low spur

or speed is not allowed.

4. Speed

a. When the unit is operating normally, speed at 200rpm. Near critical speed when the

rotational speed (2140 rpm) to accelerate a smooth crossing;

b. Using governor control steam conditioning valve, and speed will be up to rating;

c. A new installation or repaired unit should start up at low speed. When passing the test

should do excess speeding security test. Method as follows: when the quick closing valve

open, operate WOODWARD505 conditioning units to speed up to hit a critical security

devices. Close quick closing valve, at speed below 2900rpm following re wear Emergency

Trip throttle, and then allows speed to rated speed;

d. Check the normal operation and the vacuum has reached rating.

5. With Load

a. Speed at 100 kw/min or so to full load speed;

b. Check the normal work conditioning system , hydraulic and oil motivated second opening ,

load mutual adaptation;

c. Check unit sound, vibration, axial displacement, thrust bearings watts and temperature,

differential expansion, steam and metal temperature rise speed, temperature normal;

d. Adjust the water condenser level timely, water level and pressure de-aerator, steam seal

pressure, Oil Cooler oil temperature , generator cooling water inlet temperature and

pressure, water level changes in the attention of the heater.

2.4 Shutdown

1. Normal shutdown

a. Gradually unload load in order to shutdown, before charge load examinate the pump oil,

and the charge rate of less than 100 KW/min;

b. Hand Emergency Trip throttle hand and turn off shoot quick closing valve;



c. Monitor the oil down to 0.08MPa (g), then start the auxiliary fuel pump;

d. Record the time go lazy;

e. Open the steam to the steam valve marshaling, speed to critical speed, then turn off valve

to send steam;

f. Open the cylinder and the main steam pipe trap door;

g. After the turbine stop, turn off exhaust device (turn off the exhaust valve first);

h. Regular car plate until steam cool;

i. Rear cylinder temperature is below 50 C turn off the water cycle;

j. The back oil temperature is below 45 C, stop lubricating oil.

2. Emergency shutdown

The following situations happen should have an emergency shutdown.

a. Unit speed excess more than 12 percent rating stands;

b. Unit sudden has strong vibration or hear clearly the voice of the internal metal;

c. Turbine seal occurred spark;

d. A bearing unit off oil or smoke;

e. Oil down to 0.05MPa (g), failure cannot be eliminated;

f. Bearing oil temperature more than 75 C or axial displacement of more than 0.7 mm

without automatic shutdown;

g. Turbine oil system fires, and cannot be quickly extinguished, and threat to the safe

operation of generating units;

h. Tank oil level down to the lower limit, unexplained oil spill;

i. The main steam or feed water pipe rupture, endangering the safety crew.

2.5 Operation maintenance and downtime maintenance

1. The personal on duty should do the following tasks well during the operation time:

a. Units of heat engine protection device, interlock protection devices, the start switch of the

auxiliary should be put at the location;



b. Recording the instrument readings in the daily form per hour. If the readings are abnormal,

you should find out the reasons and take some necessary measures;

c. Recording the instrument readings entirely in the monthly form every day, and analyzing the

readings according to the operation conditions;

d. Inspecting the units overall per hour. If there are deficiencies in equipment, fill in the

equipment defects report form in time and pay attention to the significant deficiency;

e. Measuring, recording and analyzing the various bearing vibration regularly every day.

2. Downtime maintenance

a. If starting immediately after a short period of downtime, lower the load or load rejection

gate to fight the emergency shutdown quickly, this can greatly shorten the start up time

again;

b. Parking overhaul, make sure reduce the load slowly and operate stably at low load for a

certain period of time;

c. Vehicle should always be set, shot term park and start again, in half an hour before start up

should be changed regularly for car plate. Unit overhaul downtime, continuous disk first and

then changed to regular car plate. Bell gradually increasing time intervals until completely

cooled;

d. Long time out, should make the necessary anti corrosion treatment. Hot air drying can be

used through flow part of : sealing equipment, such as add lime or calcium chloride

desiccant and carefully adjusted bearings and other components of the corrosion prone

parts of the anti corrosion treatment, such as surface corrosion resistant material. Pipeline

related equipment, instrumentation and all water pipes in a net release. And maintenance

during the regular checks are carried out in accordance with the regulations to ensure

quality maintenance.

2.6 Synchronization Process:

Inform the electrical operator to connect the grid after testing the governing valve tightness and

the emergency breaker activation.

The operator shall focus on the air supply for the air sealing after synchronized, carefully

monitor the sound and vibration, also dont forget to check the bearing oil temperature, the oil

pressure of each system as well as the opening of governing/regulating valve. After everything is

going smooth, start the turbine protection.

When the generator was synchronized to the grid, emergency trip system should be put in to

the practice.



After grid connection, immediately load on 1000kw,for 10 minute and then increase the load to

3000kw at the speed of 150kw/min and maintaining it for the next 10 min. later on increase the

load once time to 10000kw of the speed of 150kw/min

It was not recommended to perform no load running if without any special requirements. The

generator shall be with 10% rated load at the moment connected with turbine. The back

cylinder temperature will be less than 100C ~ 120C at no load running and less than 60C ~

70C at no load running

Record all the parameters and on loading duration in the operation log book

Switch off the steam supply valve between the new steam and the bearing gland , and adjust

the steam supply based on any steam leakage phenomenon at the turbine end.

Cooling water should be supplied to generator cooler and keep the inlet air temperature around

30~ 40C, If the inlet air temperature is over 40C.

Pay attention to adjust the normal position of the condensing water level(1/2 of the water level

gauge)

After the condensing water being test to be qualified, switch off the water discharge valve and

open the valve to the de-aerator to supply water to the de-aerator.

Open the ejector pump, extract the condenser to vacuum.

Hot start time and vibration values:

R/min Min vibration value (mm)

speed accelerated 0~600 3

0.03

warm unit 600 5

speed accelerated 1000 3

warm unit 1000 10

speed accelerated 2600 5~6

0.10 over the critical state

warm unit 2600 5 0.03

speed accelerated 3000 3 0.03



Cold state start procedure:

Operations RPM Time (min)

speed rise to after driven the Rotor 0~600 2~3

check and Maintain 600 25~30

Smoothly raise speed to 600~1000 2~3


Smoothly raise speed to 1000~2600 5~6


speed accelerated to 2600~3000 2~3

Total 6~95(min)

1. Switch on the AC and DC supplies from LTP Panel.

2. Turn on MK switch

3. Start the DC field from Scada.

4. Check the generator voltage; shown on LTP Panel, when it reaches 6.3KV, generator is ready

for synchronization.

5. From computer, select the breaker of generator. Give the synchronization command by

clicking on synchronization start button

6. On synchronoscope when the Dot reaches the midpoint and turns green, that means

voltage and frequency are matched and generator is synchronized.

7. Now turbine operator will start taking the load

8. Maintain the power factor around 0.95.

Boiler Operation (2)

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