TECHNOLOGY EXCELLENCE A “DESIGN & ENGINEERING”

Generating for Generations

MSPGCL, Koradi Thermal Power Station, (3 x 660 MW)

TECHNOLOGY EXCELLENCE A “DESIGN & ENGINEERING”

• MAHAGENCO has the highest overall Generation capacity & the

highest installed thermal generation capacity amongst all the states

Power Generation utilities in India. In terms of installed capacity, it is

the second highest generation company after NTPC.

• MAHAGENCO having generation capacity of 13602 MW comprising

• Thermal 10170 MW ( 7 Plants)

• Hydro 2585 MW (26 Plants),

• Gas 672 MW (1 plant) &

• Solar 180 MW


MAHAGENCO Overview


Unit No. Capacity (MW) Commercial Operation Dates

Current Status

Koradi Unit 1 120 (de-rated to 105) 03.06.1974

Decommissioned on08.01.2011




Koradi Unit 5 210 15 July, 1978 Decommissioned from 15.03.2017

Koradi Unit 6 210 30 March, 1982 Completed R&M in

Koradi Unit 7 210 13 January, 1983 In service

Koradi Unit 8 660 16 December, 2015 In service

Koradi Unit 9 660 22 November, 2016 In service

Koradi Unit 10 660 17 January, 2017 In service



Koradi TPS Overview


Water Requirement 660 MW generation


• Raw water which is the primary source for generation of electricity is extracted from natural water bodies (Rivers, Lakes and Reservoirs / Dams).

• Raw water requirement: • Raw water requirement for power generation

from 3 x 660 MW units.• i.e 1980 MW @ 100% PLF• Raw water requirement 3.5 M3/MWHr• Daily Requirement 1980x3.5x24 = 166 MLD• Yearly Requirement 60.71 MM3

• The primary source of Raw water is Pench khairee Dam situated 28 Km from Koradi. The pench Dam receives backwater of Totladohreservior .

• Koradi TPS & Khaperkheda TPS has entered into an agreement with Water resource department GoM for supplying raw water for Industrial and Domestic purpose.


Available Sources of water for Koradi TPS


Dam Live storage capacity (MM3)

Available water as on 28.04.2019

(MM3)

Reservations

Totladoh 1016 17.42 (1.71%) Koradi + Khaperkheda – 67

Penchkhairee

144 40.59 (28.59%) NMC - 230Others -12

One Irrigation cycle comprises of 150 MM3

• The availability of raw water in these water bodies dependupon the receipt of rainfall in that particular region.

• In recent years it has been observed that the rainfallpattern in the entire parts of India has been irregular.

• Taking the note of this, MAHAGENCO envisaged theneed for water conservation in its projects.

• Looking to the short fall between demand and allocationof water for TPS it was necessary to find out betteralternative for water source.


Sources of water for Koradi TPS


Sr. No.

DESCRIPTIONS (1) KAMTHIKHAIRI

PROJECT

(2)KOCHI

BARRAGE at Maharashtra MP

Border

(3)RAHRI

BARRAGE

(4)AMBHORA BARRAGE

BhandewadiSTP

1) Location On Pench River U/S

On KanhanRiver on U/S Near Saoner

On KanhanRiver on D/S Near Mauda

On KanhanRiver on D/S

Near Kuhi

On Nagpur city sewage

water2) Additional Quantity

in MM352.25 MM3 52.25 MM3 52.25 MM3 52.25 MM3 --

3) Pipeline Length in Kms.

26 Kms. 30 Kms. 46 Kms. 80 Kms. 16.2 Kms.

5) Capital Cost at that Time in Crs.

60 Crs. 311 Crs. 260 Crs. 200 Crs. 234 Crs. (Including

O&M for 10 years)

6) Water Cost Rs. Per 10 Cum

Rs. 34.80 Rs. 12.00 Rs. 12.00 Rs. 12.00 Rs. 14

Remarks Reservation was not available for Industrial Use.

Catchment Area of this barrage falls under MP involving forest land and also inter state project . MoEFhad not cleared the project..

High capital Cost, High Energy Consumption and O&M Cost

High capital Cost, High Energy Consumption and O&M Cost

Easily available and less expensive than other sources



• MAHAGENCO taking cognizance of the issue implemented a project of reusing tertiary treated water for cooling purpose from Municipal Corporation STP in its newly commissioned supercritical units at KoradiTPS.

• This has been a state of art project which is implemented first time in India effectively. By implementation of scheme of reuse of treated municipal water from STP for its ash disposal and cooling purpose, 660 MW units of Koradi TPS have saved raw water requirement 130 MLD to the tune of 45 MM3/annum.

• The Sewage treatment plant situated at Bhandewadi is a joint venture between Mahagenco & Nagpur Municipal corporation under waste to energy project. The raw sewage from Nagpur city is collected & treated to achieve desired parameters.

• The plant consist of Primary, Secondary & Tertiary treatment incorporating clarifiers, sequential batch reactors, chlorination & deep bed media filters for treatment.





Bhandewadi STP, Near Nagpur (130 MLD)



Bhandewadi STP, Near Nagpur (130 MLD) Project layout

KT Weir

Nag Nallah

Intake Structure & Raw sewage pump house(130 MLD)

STP, TTP & Treated water Pump house(123 MLD)

Bhandewadi Existing STP 100 MLD

One day storage

reservoir at Koradi TPS85000 x 2

MS pipeline 1200 mm diaof 2.3 kms MS pipeline 1200 mm dia of 19.5 kms

KT weir inlet channel

Grit Chamber with coarse screen

Raw sewage pump House at HiwariNagar

RAW SEWAGE TRANSMISSION

PIPELINE 2.3 KM , (HIWRI NAGAR

to BHANDEWADI

Fine Screen & Grit ChamberClassifier &

Organic return pump

Distribution Chamber

Clarifier A Clarifier B Clarifier C Clarifier D

SBRSBR

SBR

SBR

SBR

SBR

SBR

SBR

SBR

ParshallFlume

Chlorine Contact tank Pump House

Deep Bed Filter Media

Tertiary treated Sump/ pump house

KTPS 3X 660 MW, KTPSOne Day Reservoir

ClariflocculatorBackwash Recovery System Thickner

Backwash water sump

Supernatant to Chlorine Contact tank

Sludge from primary clarifier & SBR basin

Gravity Sludge Thickner

Gravity Sludge Thickner

Return to Intake

Anaerobic Digester

Anaerobic Digester

Anaerobic Digester

Anaerobic Digester

Gas Holder

Gas Holder

Centrifuge

Sludge Cake



Process Treatment at Bhandewadi STP

• Raw sewage of Nagpur city intake at Hiwari Nagar pump house from Nag River.• 6 +2 Pumps of 995 cu.m/hr capacity

Mechanical cable rake bar screens

Garbage removed upto 50 mm size


Primary Treatment


• Inlet chamber • Fine screens • Grit chamber• Parshall flume• Alum dosing system• Primary clarifier distribution chamber• Primary clarifier

Primary Treatment



Inlet Chamber:•Raw sewage free from suspended impurities taken at the inlet of Bhandewadi STP.

5 Moving screens for garbage removal


Primary Treatment


• Grit removing chamber• Clasifier and organic return

pump


Primary Treatment


PARSHALL FLUMEFerric alum dosing

4 PRIMARY CLARIFIERS

SBR (Sequential Batch Reactor)

2 Basins – 1st Hr filling + aeration + sludge circulation2 Basins - 2nd Hr filling + aeration + Ferric chloride dosing2 Basins – 3rd Hr settling of sludge2 Basins – 4th Hr Decanting

4 sensors• If MLSS > 3500 ; surplus activated sludge pump pick up.•Temp sensor•DO sensor (24 Blowers)DO > 3 ppm blowers offDO < 2.5 ppm blowers on• Level indicating transmitter – 5500 mm level.



• Aerobic biological process including sequential batch reactor (Auto selector basin)

• Ferric chloride is added.

Secondary Treatment

SBRDistrubitionchamber

ReducesNitrogenBODCODTSS

Nitrification - Nitrification results from the oxidation of ammonia present in the sewage by Nitrosomonasto Nitrite.

Subsequently oxidation of the Nitrite to Nitrate by Nitrobacter.

Denitrification - releases Nitrogen which escapes off as an inert gas into the atmosphere.

The Nitrifying bacteria are strict aerobes and require more than 2mg/l dissolved oxygen in SBR basin to avoid oxygen limitation.


Sequential Batch Reactor



Secondary Treatment


•Decanted water after sequential batch reactor

•Decanted water is subjected to further treatment by means of chlorination.


Chlorination Treatment


•Overflow and under flow baffle walls are provided in chlorine contact tank.


Tertiary Treatment


•Treated sewage from Chlorine contact tank is pumped to the Deep Bed multimedia Filters.

Air scoring and backwashing


Sludge Handling


• Secondary treated sewage pumping station

• Primary sludge pumping station

• Inlet distribution chamber• Gravity sludge thickner• Thickened sludge pumping

station • Anaerobic sludge digesters• Gas holder• Digested sludge storage tank• Digested sludge dewatering

unit• feed pumping station• Sludge dewatering unit



ANAEROBIC DIGESTORTo reduce putrescibility due to pathogenic organism in sludge and also improve dewatering characteristic

GAS HOLDERBiomass produce comprises of Methane, Carbon dioxide, Ammonia, Hydrogen sulphide etc

CLARRIFLOCCULATORFunction as clarifier

THICKNERDesign to thick the sludge from clarriflocculator

Tertiary treated water pumped at Koradi TPS6 + 2 pumps @995 M3/Hr each



Tertiary Treated Water Reservoir

•TTW after media filtration received in reservoir at 660MW Koradi TPS.

•85000 x 2 sumps


Forebay & NDCT


e

• Treated Water from TTWR comes into forebay and distributed in NDCTs.


The sewage Treatment Plant followed by tertiary treatment is designed to meet the standards for treated Effluent as given below:


Sr. No. Parameter Unit Raw Sewage Quality Tertiary treated

1 pH -- 6.8 – 7.8 7.3

2 TSS mg/l 300 < 5

3 Total BOD mg/l 250 < 5

4 Total COD mg/l 500 < 30

5 Total Kjeldal Nitrogen mg/l 45 < 10

6 Total Phosphorus mg/l 8 < 0.5

7 Total Alkalinity mg/l 220 < 200

8 Total Dissolved Solids mg/l 735 < 200

9 Total Coliform MPN/100 ml

> 16,00,000 < 2

10 Feacal Coliform mg/l > 16,00,000 < 2


Water Analysis Report Using IS 10500 : 2012 Standard


Sr. No.

Parameter Unit TTW Quality

Acceptable limit

1 Colour Hazen <1

2 Odour -- Agreeable

3 Taste -- Agreeable

4 Turbidity NTU 0.2

5 pH -- 7.0

6 FRC mg/L <0.05

7 Chloramine mg/L <0.05 4.0 Max

8 TDS mg/L 381 500 Max

9 Total Hardness mg/L 214 200 Max

10 Alkalinity mg/l 156 200 Max

11 Chloride mg/l 80.8 250 Max

12 Sulphate mg/l 34.9 200 Max

13 Nitrate mg/l 17.5 45 Max

14 Calcium mg/l 49.7 75 Max

15 Magnesium mg/l 21.9 30 Max

Sr. No.

Parameter Unit TTW Quality

Acceptable limit

16 Ammonia mg/l 0.297 0.5 Max

17 Fluoride mg/l 0.558 1 Max

18 Iron mg/l 0.143 0.3 Max

19 Manganese mg/l <0.04 0.1 Max

20 Cadminum mg/l ND 0.003 Max

21 Chromium mg/l ND 0.05 Max

22 Copper mg/l ND 0.05 Max

23 Lead mg/l ND 0.01 Max

24 Zinc mg/l 0.038 5 Max

25 Arsenic mg/l ND 0.01 Max

26 Mercury mg/l ND 0.001Max

27 Selenium mg/l ND 0.01 Max

28 Nickel mg/l <0.06 0.02 Max

29 Aluminium MPN/100 ml <0.025 0.03 Max

30 Total Colliform

MPN/100 ml Absent ND

31 E-Coli MPN/100 ml Absent ND

Sr.No. Month Generation in MUs

Sp. Water Consumption

(LTR/KWH)1 Apr-18 809.16 4.3922 May-18 781.83 4.5293 Jun-18 534.60 5.2804 Jul-18 603.25 4.0745 Aug-18 427.19 4.7926 Sep-18 438.04 5.2907 Oct-18 612.01 4.7118 Nov-18 682.49 4.6609 Dec-18 594.87 4.28210 Jan-19 698.52 3.81011 Feb-19 881.32 3.21612 Mar-19 872.20 3.344


Specific water Consumption for 660MW


•Recently MoEF&CC has issued norms for specific water consumption as per notification Dtd. 07.12.2015. As less than 3.5 lit/kwh.

•From the adjacent table it is seen that 660 MW KTPS, Koradi are meeting the norms of specific water consumption.

•Achievement of the norms can be attributed to use of Tertiary treated water from Bhandewadi STP & efforts for ZLD.


Efforts for zero discharge


• The water approx300-400 M3/hr isflowing throughsurface drains. Twodrain pits areproposed for re-circulation of surfacedrain.

• Collected water isusing for ashdisposal aftertreatment at ETP

AHP side drains

Surface drain collection pit



EFFLUENT TREATMENT PLANT

TTWR UF RO MB• All the plant drains collected at ETP and reuse for ash handling• Effluent treatment plant Discharge - 450 M3/Hr. (For Ash Disposal)• Effluent treatment plant Discharge- 250 M3/Hr. (For CHP)

• The existing units of 3x660MW Koradi TPS are using thetertiary treated water only for ash disposal and cooling purpose.

• However now considering the DM consumption pattern of660MW and observing the scarcity of fresh water it is necessaryto utilize the treated sewage for producing DM water.

• To produce D.M water from treated waste water of STP requiresdifferent arrangement for treatment such as reverse osmosis(R.O)

• The use of tertiary treated water for production of DM water willreduced the use of fresh and save valuable fresh raw water.


Future Plan


TTWR UF RO MB DMST

• Recovery of Effluent from Ultra filtration unit for reusing it in SBA and MB regeneration in DM plant.

• The organic sludge generated from Bhandewadi STP can be utilized as biomanure. Efforts are being made to tap the market potential of its use for gardening and agriculture.



TTWR UF RO MB



TTWR UF RO MB

The nitrification of ammonia can be represented as given below:-

- 2NH4+3O2 Nitrosomonas> 2NO2-+2H2O+4H++New

cells

- 2NO2-+O2 Nitrobacter >2NO3

-+New cells

Denitrification of Nitrates can be represented as,

- NO3-+BOD => N2+CO2+H2O+OH-+Cells

Denitrification releases Nitrogen which escapes off as an inert gas into the atmosphere


BIOLOGICAL REACTIONS IN C-Tech BASIN


TECHNOLOGY EXCELLENCE A “DESIGN & ENGINEERING”

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