Tender Document for Repowering Project of Ghorasal 3rd Unit - BPDB

pump or steam jet air ejector will start up if the pressure switch at the condenser
indicates that the vacuum has decayed to an alarm lever.
3.3.10 Boiler Drains and Sample Coolers
The drains of each heat recovery steam generator shall be taken to the
blow-down tank where the high energy is dissipated by flashing the liquid
by steam. The flashed steam shall be vented to atmosphere and the water
shall be discharged to the blow-down tank drain.
The drain lines from the heat recovery steam generator steam lead and the
superheater inlet drain and superheater inlet and outlet shall be located at
this station along with coolers for the feedwater samples from the boiler
feed pump discharge.
3.3.11 Fire Protection System
A CO 2 fire protection system shall be provided for the gas turbine generating
units complete with CO 2 cylinder kept in a container/shed/room. Proper
water hydrant system shall also be provided for other area, equipment and
facilities. Fire protection wall and Deluge system is required for all outdoor
transformers. Required nos. of portable DCP/ CO2/ Foam cylinders to be
provided in different areas of the power plant.
3.3.12 Potable Water system
Potable water system to the plant area and other plant related area should
be included with the Tender.
3.4 Electrical System
The electrical system shall consist of apparatus required to operate the gas
turbine generating units, the heat recovery steam generators, steam turbine
generating set, associated equipment, and step-up transformer and 230kv
switchgear equipment necessary to delivery power to the 230 kv national
grid system.
3.4.1 Electrical system interrupting capacity
In this specification, the system and equipment ratings and characteristics
are based on the following preliminary data :
- 230 kv switchgear : 40 kA
- Generator switchgear : 100 kA for GT
- 6.6 kv switchgear : 17.5kA
- 400 V switchgear : 25 kA
3.4.2 Generators
The gas turbine generators shall be TEAWC type.
Each generator shall have a complete rotating rectifier type excitation system
or static excitation system mounted in a suitable enclosure including
rectifiers, static voltage regulator and required control functions. If rotating
rectifier type excitation system is not used and external static excitation is
used, separate excitation transformer shall have to be provided for each
generator.
Re-Powering Ghorasal 210 MW 3 rd Unit (Vol-2A of 2) 38