Boiler Operation:Damper Opening: (cold state)

When the hot gases temperature at the cooler exhaust is at 350-400C then

10% inlet damper open

10% outlet damper open

90% by pass damper open

After 30 minutes

When temperature at cooler exhaust is at 450C then

20% inlet damper open

20% outlet damper open

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 respectively100% inlet damper open

100% outlet damper open

100% by pass damper closed

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

Sr.NoOutlet Inlet Damper (%age) By Pass Damper (%age)Hot Gas Temperature (C)Time(min)

1109030

2208025045

3307030065

4406035085

55050400105

61000450120

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.NoOutlet Inlet Damper (%age) By Pass Damper (%age)Hot Gas Temperature (C)Time (min)

2208025015

3406030025

4604035035

5802040045

6100045060

Shut Down:-

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, 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.

Blow Downs:-

(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)

Alkalivity(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 = -0.080MPaMaintain 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)Steam Turbine

Before turbine start up:

1. cooling tower water level = 2800mm

2. Jet water tank level = 1500mm

3. Oil tank level = 234mm

4. De Aerator water level = 1600mm

Check all parameters and all drain valves should be opened.

Turbine Start Up:

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 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 every thing 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 guage)

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/minminvibration value (mm)

speed accelerated 0~6003

0.03

warm unit 6005

speed accelerated 10003

warm unit 100010

speed accelerated 2600 5~60.10 over the critical state

warm unit 260050.03

speed accelerated 300030.03

Cold state start procedure:

Operations RPMTime (min)

speed rise to after driven the Rotor0~6002~3

check and Maintain60025~30

Smoothly raise speed to 600~10002~3

check and Maintain100025~30

Smoothly raise speed to 1000~26005~6

check and Maintain260015~20

speed accelerated to 2600~30002~3

Total6~95(min)

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

2. Turn on MK switch3. 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 synchroscope when the Dot reaches the mid point 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.