Case Study- Rihand-2CONTINGENCY ARRANGEMENT

CONTINGENCY ARRANGEMENT DURING COMMISSIONING
INITIAL DM WATER & AIR REQUIREMENT
Temporary line of 200 Nb pipe with valves about 200 meters was laid
from stage I at a location in between unit 2&3 for HYDRO TEST of
boiler#3 initially and kept in use till the completion of both units acid
cleaning.
COMPRESSOR:
The compressor cooling water requirement for initial trial run of the
compressor was met by temporary open cooling water with the use of
DM water teed off from the line laid for boiler hydro test purpose. This
arrangement was retained till regular ECW system was made ready.
MAIN CONTROL ROOM AC PLANT:
AC plant make up water was not ready due to the pipe trestle erection
problem, as the same could not be erected by virtue of lay out and
pending building completion clearance.
The cooling water and chilled water initial filling and make up
requirement was met by laying a 3 inch line from the unit-2 fire
hydrant system and the same was maintained for a long time as the
trestle erection clearance was given very late.
FIRE FIGHTING SYSTEM:
The stand-alone fire fighting system for stage two was not ready
during the initial commissioning of start up transformer and unit
auxiliary transformers.
From the existing stage – I, a tapping was taken and laid temporary 4
inch line and connected to the transformer emulsi fire system line and
subsequently connected to stage II mains.
NEUTRALIZATION OF ACID:
The neutralization of spent acid was piped to the stage I , DM effluent
tank ( about 1.5 km away ) for treatment with NaOH & final discharge
to the regular drainage after ensuring the discharge water is fit for use
so that water contamination is minimized. Based on unit#3
experience, NaOH was procured in tankers & unloaded in Stage-I DM
plant tanks to send NaOH through pipe lines connected to effluent
tank, unlike unloading by the drum. The spilled acid on the floor /
equipment is neutralized with lime and washed with water.
Page 15 of 175
BENCH MARKS AT RIHAND SITE
THE DRUM LIFTING OF UNIT#3 ACHIEVED ON 29.03.2003 i.e.
WITHIN 9 MONTHS AND 26 DAYS OF THE CONFIRMATION OF ORDER,
WHICH IS SHORTEST TIME TAKEN SO FAR FROM THE DATE OF
CONFIRMATION OF ORDER TO DRUM LIFTING.
THE DRUM LIFTING OF UNIT#4 ACHIEVED ON 11.07.2003 WITHIN 3
MONTHS & 13 DAYS AFTER FIRST DRUM LIFTING, 94 DAYS IN
ADVANCE w.r.t. L2 SCHEDULE.
SITE HAS ACHIEVED MORE THAN 3000MT PHYSICAL ERECTION IN
BOILER PACKAGE 2X500MW CONSECUTIVELY FOR THREE MONTHS.
(NOV’03 – 3714MT, DEC’03 – 3412MT & JAN’04 – 3174MT).
HIGHEST TONNAGE IN 500MW BOILER IN A SINGLE MONTH –2071
MT (NOV’03)
HIGHEST HP JOINTS (EQ.) IN 500MW BOILER IN A SINGLE MONTH –
6310 NOS (NOV’03).
HIGHEST TONNAGE IN 2X500MW BOILER IN A SINGLE MONTH –
3714MT (NOV’03)
HIGHEST TONNAGE IN ESP#4 500MW IN A SINGLE MONTH – 874MT
(DEC 03).
THE ENTIRE CONDENSER TUBE INSERTION (24398 NOS)
COMPLETED IN A RECORD TIME OF 26 DAYS AND ALSO HIGHEST
3350 NOS TUBE INSERTION IN A SINGLE DAY ACHIEVED ON
27.12.2003.
BOILER # 3 & 4 HYDRAULIC TEST OF DRAINABLE PORTION
COMPLETED ON 30.01.2004 AND 19.06.2004 –
•IN A FIRST FILL ITSELF i.e.IN A SINGLE FILL OF BOILER.
•PRESSURE DROP OF MERE 2 KG/CM2 FOR A PERIOD OF HALF AN
HOUR (AGAINST PERMITTED NORMS OF 15 KG/CM2 ) AT THE FULL
TEST PRESSURE OF 310.50 KG/CM2
•TEST SUCCESSFULLY COMPLETED IN LESS THAN 24 HRS.
BEST SAFETY AWARD FOR BHEL SITE BY NTPC FOR THE YEAR
2003-04.
BOTH 500MW UNITS GENERATED AT A PLF MORE THAN 90%
DURING THE FIRST YEAR OF OPERATION. THE UNITS WERE
STABILISED IN A MINIMUM TIME.