NTPC LIMITED
PROJECT	: BARETHI STPP (4x660 MW)
PACKAGE NAME	: MAIN PLANT TURNKEY PACKAGE

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“Salient Technical Features of the equipment/systems/services covered in IFB No. 40031210 dated 31.12.2014, Bidding Document No. CS-9579-001(R)-2 are mentioned below. These Salient Technical Features are mentioned only to facilitate the prospective bidders to prima-facie understand the requirements under the tender and shall not in any way limit or alter the scope of work and technical features/specification of equipment/ systems/ services covered in the Bidding Documents. Detailed provisions in regard of scope of work and technical features/specification of equipment/systems/services, contained in the Bidding Documents shall be final and binding.”

ABRIEF SCOPE OF WORK

The Brief scope of work for the subject Main Plant Turnkey Package for Barethi STPP, Stage-I (4x660 MW) is as follows:

Design, Engineering, Manufacture, Supply, Construction, Erection, Testing & Commissioning works for the Main Plant Turnkey Package for Barethi Super Thermal Power Project, Stage-I (4 x 660 MW), on BTG island basis, covering the following activities and services in respect of Steam Generator, Steam Turbine Generator and Electrostatic Precipitator, Ash Handling, Coal Conveying facilities ,electrical systems including Switchyard, Firefighting, associated Control &Instrumentation and Civil, Structural and Architectural works and Solar PV Plants at roof-top covered under the specifications:

a)Basic Engineering of the plant;

b)Detailed design of all the equipment and equipment system(s) including civil, structure steel & Architectural works included in bidder's scope.

c)Providing engineering drawings, equipment sizing & performance data, instruction manuals, as built drawings and other information;

d)Compliance with statutory requirements and obtaining clearances from statutory authorities, wherever required;

e)Complete manufacturing including shop testing/type testing;

f)The Civil, structural and architectural works including topographical survey, Complete site levelling, construction water for plant area, water supply and sanitation, infrastructure works including major roads, drains as envisaged in tender GLP, Effluent &sewage treatment facility for plant, main plant area structures and foundations including turbine building, bunker building, boiler structure, ESP structure, service building, compressor house, coal conveying facilities, Ash handling plant, chimney, pipe/cable galleries and pipe/cable trenches, duct banks, pedestals, other buildings and structures, transformer yard structures, switchyard structures, fuel oil handling system and fire protection system (Partly) structures and foundations, bridges and culverts for crossing of roads / Rail Tracks inside plant area, landscaping and other miscellaneous buildings and structures.

g)Packing and transportation from the manufacturer’s works to the site including logistic studies, insurance, customs clearance & port clearance, port charges, if any.

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h)Receipt, storage, preservation, handling and conservation of equipment at the site;

i)Fabrication, pre-assembly, if any, erection, insurance, testing, commissioning and completion of facilities including putting into satisfactory operation all the equipment including successful completion of initial operation;

j)Performance and guarantee tests after successful completion of initial operation;

k)Supply of spares on FOR site basis;

l)Reconciliation with Customs Authorities, in case of foreign Bidders;

m)Satisfactory conclusion of the Contract;

n)Insurance and other requirements

Detailed scope of work has been specified in the bidding documents.

B SALIENT TECHNICAL FEATURES

1.00.00Steam Generator

1.01.00Type

The Steam Generator shall be of single pass (Tower type) or two pass type using either spiral wall (inclined) or vertical plain / rifled type water wall tubing.

1.02.00Other Features of Steam Generator Design

The Steam Generator shall be direct pulverized coal fired, top supported, single reheat, radiant, dry bottom, with balance draft furnace and shall be suitable for outdoor installation. The evaporator of Steam Generator shall be suitable for variable pressure operation from subcritical to supercritical pressure range.

1.03.00Rating of Steam Generator(s)

Steam Generator shall be designed to cater to duty requirements at Boiler Maximum Continuous Rating (BMCR) specified below:

Capacity

of Steam

Steam Flow

Temp.

Pressure

Generator and Rated

(T/Hr)

(Deg C)

Kg/cm2(a)

Steam parameters:

i)

At

super-heater

102% of

the

To

achieve

turbine

To achieve turbine

outlet

turbine

VWO

throttle

main

steam

throttle

steam

steamflow

temperature

as

pressure

as

requirement.

indicated

in

clause

indicated in clause

3.02.00.

The

steam

3.02.00. the steam

temperature

at

pressure

at

Superheater

outlet

superheater

outlet

shall

be

atleast

3°C

shall

be

atleast 9

higher than the

rated

kg/Cm2

higher

main

steam

than

the

rated

temperature

at

HP

main

steam

turbine inlet.

pressure

at HP

turbine inlet

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ii) At re-heater outlet	-	To achieve reheat steam					---
		temperature		at	Turbine
		Inlet	as indicated			in
		clause	3.02.00		of	this
		Sub-section. The steam
		temperature		at	reheater
		outlet shall be atleast 3oC
		higher	than	the rated
		reheat			steam
		temperature at IP turbine
		inlet.
iii) Feed Water Temp.		To be optimized by the
at Economizer Inlet		bidder	but	not		less
		than 285oC

1.04.00Limiting Parameters for Steam Generator Design

The Steam Generator design shall comply with the following limiting parameters with ‘design coal’ firing, under stipulated ambient air condition i.e. 27 degree Celsius temperature and 60 % relative humidity:

		Flue gas temperature at air-heater outlet -						125oC (minimum)
		(Corrected) at 105% TMCR & 100 % TMCR load
1.05.00		Operating Requirements
	1.		Minimum		load	without oil	40% BMCR
			support for flame stabilization
	2.		Operation without HP heaters in				Steam generator shall also be designed for
			service				continuous operation with HP heaters out of
							operation. The steam generator heat output
							under HP heaters out condition shall be at least
							100% BMCR heat output with HP heater in
							service.
	3.		Steam generator control range				The automatic control range of Steam
							Generator shall be from 50% TMCR to 100%
							BMCR. Under the above control range, the
							steam temperatures at SH & RH outlets shall
							be maintained at their rated values.
	4.		Mode	of	Steam	Generator	The Steam Generators shall be designed for
			Operation				variable pressure operation. Thermal design of
							Steam Generator and the selection of materials
							shall be suitable for variable pressure
							operational modes.
	5		Rate of loading / unloading
			a)	Step load change			Minimum + 10% per minute
			b)	Ramp Rate			(i) Minimum + 3% per minute (30% to 50%
								load)
							(ii)	Minimum + 5% per minute (50% to 100%
								load)

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1.06.00Coal data/Fuel Oil System

The primary fuel for the main steam generator shall be coal. Heavy Fuel Oil (HFO) shall be used for start-up, coal flame stabilization and low load operation of the main Steam Generator(s). Further, Light Diesel Oil (LDO) shall be used to facilitate black start of units when no auxiliary steam is available from external source

2.00.00 Electrostatic Precipitator (ESP)

2.01.00 System Description:

The Electrostatic Precipitators shall be of outdoor type and installed on the cold end side of regenerative air preheaters. The flue gas shall be drawn from air preheater outlets of the balanced draft, pulverized coal fired Steam Generator and guided through adequately sized duct work into the specified number of independent gas streams of each ESP. Similarly, the flue gas after the Electrostatic Precipitators shall be led to the suction of the induced draft fans.

2.02.00Service Conditions

The Steam Generators are designed to burn pulverised coal. HFO shall be used during startup and at low loads for warm up and flame stablisation of Steam Generator. Further, Light Diesel Oil (LDO) shall be used to facilitate black start of units when no auxiliary steam is available from external source.The ESP shall be designed to remove fly ash particles (to meet the stipulated ESP emission levels) from the flue gas generated in the Steam Generator with pulverized coal firing.

3.00.00 Steam Turbine

3.01.00Type

The steam turbine shall be tandem compound, single reheat, regenerative, condensing, multi-cylinder design with separate HP, separate IP and separate LP casing(s) OR combined casing for HP-IP and separate casings for LP Turbine directly coupled with generator suitable for indoor installation.

3.02.00Rating

The steam turbine generator unit shall conform to the following design and duty conditions:

1.	Output under	economic	maximum	:	660 MW
	continuous rating	(EMCR)	(guaranteed
	output load) at generator terminals
2.	Turbine throttle steam pressure			:	247 to 270 Kg/cm2 (abs)
					(Bidder to optimize)
3.	Turbine throttle main steam temp.			:	565 to 600 oC
					(Bidder to optimize)
4.	Reheat steam temp. at turbine inlet			:	593 to 600oC
					(Bidder to optimize)

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5.	Condenser pressure	:	77 mm Hg (abs)
6.	Turbine speed	:	3000 rpm
7.	Frequency variation range around rated	:	+ 3% to - 5% (47.5 Hz to 51.5
	frequency of 50 Hz		Hz)

3.03.00 Other Features

Turbine shall be capable of operating continuously with valves wide open (V.W.O.) to swallow at least 105% of EMCR steam flow to the turbine at rated main steam and reheat steam parameters and also the corresponding output shall not be less than 105% of rated load with 3% make up and 77 mm Hg (abs) condenser pressure.

The steam turbine shall have minimum seven uncontrolled extractions for regenerative feed heating based on optimised cycle and shall be suitable for satisfactory operation under tropical conditions.

4.00.00 Generator

4.01.00Type

Three phase, horizontal mounted, indoor installed, two-pole, class-F winding insulation, Stator water/ hydrogen cooled, cylindrical hydrogen cooled rotor type.

4.02.00Rating

Generator and its excitation system shall have a capability at least matching the declared maximum continuous rated output of the associated steam turbine (for the designed secondary cooling water temperature) at all power factors between 0.85 lagging and 0.95 leading with +3% to -5% frequency variation, terminal voltage variation of +/- 5% and combined voltage & frequency variation of 5%. It shall be ensured that when the Generator is working at this capability and design cooling water temperature, no part of the Generator shall attain a temperature in excess of the temperature limits specified for class-B insulation as per IEC-60034.

4.03.00Also the generator and its excitation system shall be capable of continuous stable operation without any excessive temperature rise at the peak output of the associated steam turbine under VWO & HP heater out condition, etc. as available for the designed secondary cooling water temperature, at all power factors between 0.85 lagging and 0.95 leading with +3% to -5% frequency variation, terminal voltage variation of +/- 5% and combined voltage & frequency variation of 5%. Temperature of different parts may exceed those permissible for class-B insulation under such operating conditions, but shall be lower than those permissible for class-F insulation as per IEC-60034.

4.04.00Rated Parameters

1.	Power Factor	-	0.85 (lag)
2.	Terminal voltage	-	In the 18 to 27 kV range
3.	Frequency	-	50 Hz
4.	Speed	-	3000 rpm
5.	Short circuit ratio	-	Not less than 0.48 (without any
			tolerance)

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5.00.00Ash Handling Plant

Ash handling system consists of the following sub systems:

a)Bottom Ash Handling System

i)Jet pump and Water Impounded Hopper System – An intermittent system consisting of water impounded hoppers, clinker grinders, jet pumps, etc.

OR

ii)Submerged Scrapper Conveyor and dry type hopper System – A continuous system consisting of dry type Bottom Ash hoppers, submerged scrapper conveyors, clinker grinders, bottom ash slurry trench, slurry transportation pumps, etc.

b)Dry Fly Ash Conveying system

Two alternatives for pneumatic conveying system are specified for conveying of fly ash in dry form from ESP hoppers upto buffer hoppers. i.e. vacuum conveying system or pressure conveying system

i)Vacuum Conveying System

It shall consist of liquid ring vacuum pumps, material handling valves, cast iron and MS pipes, instrument air compressors etc.

OR

ii)Pressure Conveying System

It shall consist of screw compressors, air lock/pump tanks, ash intake & discharge valves, CI, MS pipes, instrument air compressors etc.

c)Dry Fly Ash Transportation system

The dry fly ash from the buffer hoppers in each unit shall be transported to either silos for slurry disposal system or to storage silos. The user industries shall take the dry fly ash from storage silos either in closed tankers or in open tankers.

d)Ash Disposal System

i)Bottom ash, economizer ash and air preheater ash (if applicable) shall be disposed offfrom ash slurry sump to ash disposal area by bottom ash slurry disposal pumps.

ii) The fly ash and air preheater ash (if applicable) shall be disposed off by high concentration slurry disposal (HCSD) system. In high concentration slurry disposal (HCSD), fly ash shall be mixed with water in suitable proportions to form high concentration slurry. The slurry shall be pumped to the disposal area by means of positive displacement pumps.

6.00.00Coal conveying facilities, Fire detection & protection system, Compressed air system, A/C and ventilation system, Hydrogen generation system, Condensate Polishing system shall be as per the scope of technical specification.

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7.00.00Electrical Systems

The electrical items shall cover following:

Generator, Excitation System and its Auxiliary Systems

Motors, Electric Actuators

Generator Busducts, MV Busducts and Generator Circuit Breaker (if applicable).

Power Transformers, Auxiliary Oil Filled Transformers, Indoor Transformers

MV Switchgears, LV Switchgears and LV Busducts, Numerical Relay Networking, DC System, Battery and Battery Charger

HT Power Cables, LT Power and Control Cables, Cabling, Earthing and Lightning Protection, Lighting, DG Sets

765/132 KV AIS.

Control & Protection of EHV system and Generator Relay Panels, Substation Automation System (SAS) based on IEC 61850 protocols.

Construction Power facilities

Type Testing and Mandatory Spares as specified.

8.00.00 C & I Systems

The control system, called Distributed Digital Control Monitoring & Information system (DDCMIS) is envisaged to be procured under this package for control and operation of

Integral control & protection of boiler including Burner Management System and Boiler protection system.

The integral control & protection of Steam Turbine Generator including Electro-hydraulic control & Turbine Protection system.

Modulating controls of the Steam Generator (SG) {Combustion Control- Fuel Flow/Air Flow; Furnace Draft Control, FW flow control etc.}.

Modulating controls of Feedwater& Condensate Cycle {Hotwell level control, Deaerater Level control, Heater Level Control, etc.}.

Binary control of auxiliaries of Steam Generator (SG) {Forced draft (FD) fan, Induced Draft (ID) Fan, Primary Air (PA) Fan etc.}.

Binary control of auxiliaries of Turbine Generator (TG) {Boiler Feed Pump (BFP), Condensate Extraction Pump (CEP) etc.}.

Electrical Breaker including synchronization circuits.

Air Conditioning and Ventilation systems.

Ash Handling Plant.

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Human Machine Interface & Plant Information System (HMIPIS) is based on Large Video Screen (LVS) displays supported by TFT monitor based Operator Work Stations (OWS). These devices through customized user-friendly displays, soft alarm facia and pop-up displays are used for giving fast pin-pointed faults/ status to the operator. Local ON/OFF operation of equipments is envisaged through Graphical Interface Unit (GIU). The total system is networked through a Station-Wide LAN for use of real time data of various plant areas by other users like maintenance, planning, efficiency enhancement groups etc.

The sequence of events recording & alarm annunciation are also implemented as a part of DDCMIS system. A GPS based master and slave clock system is to be provided for uniform and synchronized timing signals throughout the entire station.

The power supply for the control system is based on 24V DC provided through microprocessor based modular charger system and for the peripherals and other subsystem through 230V Single Phase UPS.

Main Equipment related instruments like Flame Monitoring system, Coal Bunker Level measurement system, gravimetric feeder control system, Acoustic Pyrometer, Acoustic Steam Leak detection system, Furnace and Flame viewing system, Turbine stress control / evaluation system, Turbine supervisory and diagnostic system etc are also procured through this package.

Field instruments like pressure, DP, flow & level transmitter, analyzers along with their process connection & piping as well as measurement systems like vibration monitoring system etc are also procured through this package.

A plant-wide CCTV system based on IP technology is included in this package for surveillance of plant equipment as an aid to the operation.

Apart from above, an on-line Steam & Water analysis system (SWAS), PA system, Operator control desks, panels, shielded twisted pair cables as well as optical fiber cables for system interconnection and all types of Instrumentation Cables are also included in this package.

9.00.0Civil Works

The site for Plant and offsite areas comprises of layers of silty clay / clayey silt and sand/weathered rock layer at deeper depths. Open foundation and pile foundation are envisaged for major structures. The steel structures shall be pre-fabricated in factory and shall have bolted field connections (except chimney flue liners, coal bunkers & ducts which may be fabricated and welded at site).

10.00.0SOLAR P.V Plants

Solar Photo-voltaic plants to be supplied under the package shall be grid-connected rooftop SPV plants including all auxiliaries. The SPV modules must conform to latest edition of IEC 61215 / IS 14286 for crystalline silicon Terrestrial PV Modules design qualification and type approval. In addition, the modules must also conform to IEC 61730 part 1 & Part 2 or equivalent IS for construction & testing requirements respectively.

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