GENERATOR HYDROGEN GAS system commissioning.ppt

COMMISIONING OG 500MW H2 GAS SYSTEM

1. GENERATOR GAS SYSTEM GENERATOR GAS SYSTEM
COMMISSIONINGCOMMISSIONING

2. GENERATOR AIR TIGHTNESS GENERATOR AIR TIGHTNESS
TEST TEST
The two pole generator is designed with direct water
cooling for the stator winding, phase connectors and
bushings and direct Hydrogen cooling for rotor winding.
Generator losses, such as iron losses, windage losses and
stray losses are also dissipated through hydrogen. The
generator frame is pressure-resistant, gas tight and
equipped with major components mentioned above. The
hydrogen coolers are arranged vertically inside the
turbine end stator end shield.

3. PURPOSE OF ATTPURPOSE OF ATT
To ensure gas tightness of gas pipe lines
In assembled condition including valves
and instrumentation.
 To ensure gas tightness of various joints
on Generator stator, terminal bushings,
Primary Water system, Hydrogen coolers
etc.
 To ensure effectiveness of the seal oil
system at operating pressure.

4. PROPOSALPROPOSAL
The Test shall be carried out in following stages:
• Testing of pipe between CO2 Bottle Rack and Gas Unit at a pressure of
4.8 bar of Nitrogen gas for 2 hrs.
• Testing of pipe between Hydrogen Bottle rack and Gas Unit at a
pressure of 4.8 bar of Nitrogen gas for 2 Hrs.
• Testing of Pipe between Nitrogen Bottle rack and PW Tank at a
pressure of 5.0 bar of Nitrogen gas for 2 Hrs.
• Leakage Test of Generator along with Gas System using air at 4.0 bar
for 72 hrs

5. REQUISITE CONDITIONSREQUISITE CONDITIONS
Assembly of generator and fixing of end
shields and manhole covers is complete.
Seal oil system is commissioned and put
into operation for continuous running.
 Assembly of gas system piping is
complete.
 Generator terminal bushings are
connected.
 H2 gas coolers are not charged with
water.
Contd…

6. Stator winding is filled with deoxygenated primary
water. All the valves in PW system are closed. A
water manometer is connected in waste gas line
of PW Tank. Connect a 'U" tube manometer in
waste gas line of PW tank after v/v MKF91
AA505.
 Valve MKF91 AA 506 is closed. Valves MKF91
AA 513 and MKF91 AA 505 are open.(Ref waste
gas scheme)
Instrument air supply line is connected before
valve MKG25 AA 50 I (shut off valve before
compressed air filter). Air for filling should be free
from moisture, oil and any mechanical impurity.
Contd…

7. Precision Test pressure gauge of class 0.6 and least
count of 001 Kg/sq. cm is fixed for pressure
measurement at MKG25 CP001.
 A mercury manometer is connected in one line of
indicator MKG05CP501 for air pressure measurement
and for observing the leakage rate. Other pipe line is
blanked and valves MKG05 AA50 I and MKG05AA 502
are kept open.
 All the instruments in gas system are mounted as per
scheme.
Contd…

8. All the valves provided in H2 Unit are kept open so
that all the lines get pressurised during Air Tightness
Test. All valves connected to vents are kept closed.
 Valves provided in gas impulse lines in seal oil
system are open.
 Valves MKG69AA 504 and MKG69 AA 501 are
open to take dryers in service

9. METHODS OF TESTINGMETHODS OF TESTING
Testing of Pipe lines between CO2 Bottle Rack and
Gas Unit:-
Disconnect pipe lines at isolating flanges Nos. 96.
 Blank this end of the pipe line by a temporary flange.
 Keep valve MKG 59 AA 507 open (shut off valve in CO2
filter line).
 Pressurise the pipe line by N2 gas up to 4.8 bar.
 Check for leakages by applying soap solution at all weld
joints and flanges.
 If no leakage is found, observe for two hours for any
pressure drop . There should not be any pressure drop.
Depressurise and connect the pipelines back In the
system after successful completion of test.

10. Testing of Pipe lines between H2 Bottle Rack and Testing of Pipe lines between H2 Bottle Rack and
Gas UnitGas Unit
Disconnect pipelines at isolating flanges Nos. 94.
 Blank this end of the pipeline by a temporary
flange.
 Pressurise the pipeline by N2 gas up to 4.8 Bar.
 Apply soap solution at all weld joints and flanges.
 If no leakage is found, observe for two hours for
any pressure drop. There should not be any
pressure drop.
 Depressurise and connect the pipelines back In
the system after successful completion of test.

11. Testing of Pipe lines between N2 Bottle Rack and Testing of Pipe lines between N2 Bottle Rack and
PW TankPW Tank
Disconnect pipelines at isolating flanges near PW Tank.
 Blank this end of the pipeline by a temporary flange .
 Keep valve MKF81 AA 502 and valves in Nitrogen
distributor open.
 Pressurise the pipeline by N2 gas up to 5.0 Bar.
 Apply soap solution at all weld joints and flanges.
 If no leakage is found, observe for two hours for any
pressure drop. There should not be any pressure drop.
 Depressurise and connect the pipelines back to the
system after successful completion of test.

12. Leakage Test of Generator along with Leakage Test of Generator along with
Gas System using AirGas System using Air
Air Filling in Generator Casing.
Open valve MKG25 AA 50 l(shut off valve
before compressed air filter) and start filling air
in generator.
During filling observe the performance of
pressure regulating valve of seal oil system and
maintain the H2 and air side seal oil pressure as
recommended.
Close valve MKG25 AA 501 as soon as
pressure in the casing reaches 4.0 bar.
Checks during Air Tightness Test
Contd….

13. Apply soap solution for checking leakages in following Apply soap solution for checking leakages in following
areas:areas:
• Joints and bolt heads on Stator body
• Weld joints on Generator body
• Joints of terminal bushings, manhole covers, H2 coolers
etc
• Gas piping weld joints and flange joints
• Passing of valves in the system to atmosphere and
passing through valve glands
• Gas drier shell
• Seal oil Tank flange joints
Contd….

14. • Impulse line connections for pressure regulating valve
in seal oil system
• Connecting joints of all measuring instruments
provided In gas system.
• Passing of valves provided in oil I water detector lines.
• Sealing joints provided for taking out stator winding
temperature terminals.
Contd….

15. If any leakage is observed, the generator should be
depressurised and same should be attended and test
should be repeated.
Record half hourly readings on the mercury manometer
provided in H2 unit for this test and in the test gauge as
well . Record ambient and Generator temperatures also.
Observe for any pressure rise in PW Tank during test
with the help of Water manometer provided for this
purpose. If any increase is observed, stator winding
system should be checked for leakage.
If no leakage is observed, pressure drop should be
checked for 72 continuous hours.

16. COMPLETION CRlTERlACOMPLETION CRlTERlA
Air Tightness Test should be carried out for 72 hrs at 4
bar and average air loss should be calculated. The
permissible air loss for a gas tight system is below
2.4m3 at NTP. I 24 Hrs.