ASSEMBLING ACTIVITIES
a. ASSEMBLY OF TURBINE COMPONENTS IN THE TURBINE PIT
- Leveled the guide vanes and maintained its clearance as per the standard drawing.
- Attached servomotor to the guide vane assembly.
- Inserted shear pin around guide vane assembly.
- Attached turn buckles to guide vane assembly.
- Maintained shutter gap to zero between guide vanes.
- Attached the pressure balancing pipes in turbine section.
- Attached terminal housing assembly on bearing top cover.
- Plugged oil level sensor, oil-water mixture transmitter.
- Attached the RTD sensor terminal wires which was marked respectively.
- Screwed the water inlet and outlet flange of the heat exchanger and its assembly base.
- Attached oil pipeline and governor position sensor.
- Measured the clearance of turbine guide pad to main shaft using filler gauge.
- Added guide rig located below the bearing.
- Attached the water/air measuring pipelines.
- Finalized the assembly of lower bracket section, turbine section and upper bracket section.
- Performed runout test by rotating the shaft manually.
- After runout test upper bracket housing cover was assembled followed by the assembly of collector (slip) ring on the rotor shaft.
Finally, upper bracket section was covered with bracket assembly. Then RTD sensor of upper bracket sections were connected to the terminal on the upper bracket housing cover assembly. Oil level sensors, overspeed sensor, carbon brushes were connected. The shutter gaps and guide vanes top and bottom clearance were measured from the draft tube. Spiral casing and draft tube manhole were closed. Final inspection was done in all the parts before testing. Tail race gate, MIV and Servo lock was opened and guide vane opening was kept at 0 %. Now guide vane opening was gradually increased and shaft started to rotate at 251 rpm. Shaft vibration, bearing pad, bearing oil and air cooler temperature were noted. The guide vane opening was increased to attain the 320 rpm and finally 504 rpm. Data were noted in every 15 minutes intervals and temperature graph was monitored in control room SCADA. Temperature increased sharply initially and later saturated as represented in temperature saturation curve. Other parameters during no-load and load testing were satisfactory.