28 September 2022

Turbine Start up | START UP & OPERATION LIMITS | Control values for Axial displacement | bearing vibration | Shaft vibration | oil pressure | oil temperature | Temperature of bearing tungsten metal | Oil level in oil tank | Condenser pressure | Pressure limits

Turbine Start up

1.Control values for axial displacement (the rotor being positioned by working pad, the movement of rotor toward generator is plus, the opposite is minus

 Alarm value                +0.6  -1.05mm

 Shut down value     +1.2  – 1.65mm

 

2.Control value for bearing vibration

(2.1) Vibration on bearing cover (peak-peak value)

a. Normal value  ≤ 0.03mm

b. Alarm value 0.05mm

c. Shut down value  0.08mm .

(2.2) Shaft vibration (peak – peak value)

a. Normal value  ≤ 0.076mm

b. Alarm value 0.125mm

c. Shut down value  0.25mm

 

3.Control  values for oil pressure

(3.1) Normal value of mail oil pump outlet pressure 1.8MPa (17.7kgf/cm2)

(3.2) Lubricating oil pressure

Normal value 0.0785 ~ 0.118MPa (0.8 ~1.5kgf/cm2)

Alarm value 0.049 MPa (0.5kgf/cm2) automatically start up AC lube oil pump

AC oil pump starts automatically when turbine speed falls below2850rpm or Main oil pump discharge oil pressure low ≤ 1.8MPa

Turbine Shutdown value 0.039MPa(0.4kgf/cm2) automatically start up DC emergency oil pump

Value for stopping turning gear 0.03MPa (0.31kgf/cm2)

(3.3) EH anti-burning oil pressure

a. Normal value   13~14MPa

b. Alarm value 11.2 MPa

c. Shut down value  7.8MPa

 

4.Control values for oil temperature

normal value of bearing inlet oil            40~45℃

normal value of bearing housing return oil     <65℃

alarm value of bearing housing return oil             65℃

shut down value of bearing housing return oil 75℃(manual)

EH oil temperature                               40℃±5℃

 

5.Temperature of bearing tungsten metal

  Temperature of support bearing tungsten metal

  Alarm value 105 °C

  Shutdown value 115 °C  (manual)

  Temperature of thrust bearing tungsten metal

  Alarm value 100 °C

  Shutdown value 110 °C

 

6.Oil level in oil tank (indicating value of oil indicator)

  The max oil level +200mm

  The alarm value of min oil level   -180mm

  The shut down value of min oil level   -230mm

7.Condenser pressure

  Normal value   0.015Mpa (0.147kgf/cm2)

  Alarm value   >0.05Mpa (0.49Kgf/cm2)

  Shutdown value   0.055MPa (0.539kgf/cm2)

 

8.The unit is allowed to operate with30%  ~ 100% load for long time.

The operation time in which the unit carries plant load after the trip-out should not exceed 15 minutes. And this operation should not exceed once a year. This operation mode will considerably consume the lifetime of the unit. It is better to avoid adopting this mode, except absolutely necessary.

The no load operation time after trip-out of the unit should not exceed 15 min, and this operation should not exceed once a year.

Usually, the unit is not allowed to operate in electric motor mode. In case it is absolutely required, this mode of operation can only be performed once a year, on condition that the back pressure is less than 0.05MPa and temperature of exhaust casing less than 85 °C

Each time of this operation is not to exceed 1 min.

9. Pressure limits for each section of steam extraction port and regulating stage. 

10. Stop the unit if steam temperature goes less than 450°C 

 

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