31-10-2016, 10:59 AM
1462265745-42.ThermalPowerStationsPage408427.pdf (Size: 4.49 MB / Downloads: 22)
Unit Profile
NTPC Anta is a Gas-Based Combined Cycle Power Plant situated near Anta village in
Baran District of Rajasthan State. The power plant has capacity of 419.33 MW and
works on combine cycle principle. The project was installed to meet the power
demand of northern region states - Delhi, Haryana, Himachal Pradesh, Jammu &
Kashmir, Chandigarh, Punjab, Rajasthan, Utter Pradesh and Uttaranchal. Station has
completed 25 years of its commercial operation on 01/04/2014.
CONFIGURATION
There are three gas turbines At NTPC Anta with 88.71 MW capacities each. These
turbines work on Brayton Cycle principle. There is one steam turbine which works on
Rankine cycle and has a capacity of 153.2 MW. In Combined Cycle module, three gas
turbines, three heats Recovery Steam Generators (HRSG) and one Steam Turbine put
together. Thus station has a total installed capacity of 419.33 MW.
Fuel
The gas turbine is designed for firing multi-fuel such as Naphtha, HSD and Natural
gas. The primary fuel for the project is lean natural gas supplied from Western
offshore gas fields (Bombay high, South Basin, etc.). The gas is transported from the
gas fields to project site by GAIL through HBJ pipeline. These units are also capable of firing Naphtha. The annual natural gas requirement is about 490 Million SCM for 60%
PLF.
MAJOR ENERGY CONSERVATION INITIATIVES
1. Plant Auxiliaries optimization during shutdown
Reduction in running hours of CW pump, CT pumps and ARCW pump when STG goes
under shutdown. By modification, in ARCW discharge line, fire hydrant line
connected to discharge of ARCW to supply cooling water during STG shutdown.
During Steam Turbine shutdown ACRW pump (30 KW) is required to run for min 72
hrs for cooling of STG rotor shaft and its auxiliaries like CEP, HP / LP BFPs etc. As
suction of this ARCW pump is from main CW line, hence one CW and one CT pump is
required to be in service during running of ARCW pump. A modification has been
carried out through which water has been taken from hydrant header line and
connected to discharge of ARCW pumps. It has resulted in stopping of one CW , one
CT two ARCW pumps, 2 No of lube water pumps for CW and CT Pump each, CW
Screen wash pump. One Jocky pump of 15 KW runs continuously.
Total saving
achieved during the year was 257458 Kwh.
2. Plant Solar lightings
Solar Power will be the best and the most
reliable source of energy in the future. In
2013-14, NTPC Anta has installed 220nos 11W
LED based Solar Street Lighting in Reservoir
area. The total investment is Rs. 43.14 Lakhs.
Though in terms of quantity of energy it may
be small but it’s a step towards renewable
energy and the benefits are sustainable in
nature at Rs 0.245 Lakhs per year.
3. Plant Auxiliaries optimization
Modification in water supply arrangement to CCR : Due to Chocking of clarified water
pump (15 Kw) discharge line to CCR Over head tank, Pumps were continuously
running to meet the water requirement at CCR. As a part of modification, discharge
line of clarified water pump was connected with
the DM plant over head tank. By this
modification 24 hr running of clarified water
pump saved while Running of DM plant O/H
tank filling pump (15 KW) increased by 4
hrs/day.
4. Stopping of CT fans after canal
charging/closure:
During the closed cycle Cooling Water operation 10-11 CT fans run continuously.
When RMC (Right Main Canal) is charged, all CT fans are stopped. Also at the time
of closure of RMC, canal gates provided about 1.5 km away from the gates of plant
intake channel are closed to create the pondage for using the available water in the
canal, plant circulate this pondage water till it start losing on account of condenser
vacuum. As the water temperature rises, CT fans are put in service one by one to
maintain the condenser vacuum. Out of total 10 no. of CT Fans, only 5-7 No. of CT
Fans run during partial open cycle operation.
5. Offline water washing of gas turbine compressor
In Gas Turbine (GT) plant GT compressor consumes approximately two-third of the
power generated by the GT. The efficiency of compressor degrades due to fouling of
blades over the time, which reduces the power output at Generator end. In order to
clear off the fouling on blades, off-line water wash is carried out when machine is
off. Gas Turbine is cranked to 750 rpm and hot water at 60 deg. C is sprayed
through off-line water wash nozzle along with detergent solution. Subsequently, the
compressor is rinsed to remove the dirt, fouling etc. until we get specified turbidity
at exhausting water. The machine down time requirement is not less than two days.
Based on cost benefit analysis, the gain due to off-line wash has been optimized
with on-line wash.
6. Optimized operation of SWYD AC compressors
The temp of Electrical/C&I Panel room is maintained around 22° C for proper
functioning of the control panels. This temp. is maintained by running Air
Conditioning System. There are 2 Nos of Centralized AC Systems installed. One for
cooling CCR Building and One for cooling control panel room at Switchyard Control
Room. During the winter season when ambient temp goes down, requirement of
running AC System also decrease. Compressors are stopped during night hours and
only AHU (Air Handling Unit) is kept running for air circulation. Stopping of AC
compressor & its pumps in each system (2 Nos of Condensate Pump, 2 nos of
Chilled Water Pumps and One Cooling Tower Fan), Stopping of GT lube oil cooler
fan, generator CW fan and two roof extractor fan of GT and STG hall.