Combine Cycle Power Plant

Presented By Ashvin G. PatelAsst. Prof. (E.E.)GPERI, Mehsana

1

Combine Cycle Power Plant:• In combined cycle power plant (CCPP), the Brayton cycle &

Rankine cycles are combined.

2

Cont…• The exhaust of gas turbine which is at a high temperature is

supplied to steam generator as a input.• The heat energy of exhaust gas is absorbed by water. This

water converts in to high pressure steam which is supplied to the steam turbine and additional electricity is generated.

• Steam is taken from the turbine condense in steam condenser.

• This combine cycle power plant gives approximately 45% efficiency.

• Recent CCPP are designed to give efficiency as high as 58 %.

3

Advantages:1) High overall plant efficiency 2) Low investment cost 3) Reliability of supply 4) Small amount of cooling water required 5) Saving of Fuel 6) Flexibility of operation 7) Simplicity of operation

Disadvantages:

While the designing of combined cycle power plant, choise of voltage, economic load transfer, system stability should be studied.

CCPP in India:

2. ANTA, 2 x 150 MW GT  

  Rajasthan 1 x 113 MW ST 413

3. Auraya, U.P. 4 x 111 MW GT  

    2 x 103 MW ST 650

4. Kawas 4 x 105 MW GT  

  Gujarat 2 x 105 MW ST 630

5. Uchahar, U.P.   410

6. Gandhar 4 x 111 MW GT  

    2 x 103 MW ST 650

5. Faridabad, UP 4 x 131 MW GT  

    2 x 138 MW ST 800

8. Godavari Kankinada, AP. ---  4009. Vatwa, Gujarat  --- 120

Sr.No.

Name ofpower plant

Unit wiseperformance

Total installedcapacity (MW)

1. Dadri, Near Delhi

National capital

Power project - 1991

4 x 131 MW GT

2 x 146 MW ST 817

TPS in India:Sr. No. State Name of power station Capacity (MW)

1. Andhra pradesh Kothagydam 240 2. Assam Gauhati 41

3. Bihar (i) Barauni 145    (ii) Bokaro 975

    (iii) Patratu 400

4. Delhi (i) Rajghat 350 

    (ii) Badarpur300

5. Gujarat Dhuvaran (4X 63.5, 2X 140)

Ukai (2X 120, 2X 200,1X 210)

Wanakbori (7X 210)Gandhinagar (2X 120, 3X 210)

534

850

1470

8706. Haryana (i) Faridabad 200    (ii) Panipat 220

7. Madhy pradesh (i) Korba 420    (ii) Satpura 300    (iii) Amarkantak 180

8. Maharastra (i) Nagpur 480    (ii) Nasik 280    (iii) Pants 90

9. Orrissa Talcher 254

10. Tamil Nadu (i) Neyveli 600    (ii) Ennore 450

11. Uttar Pradesh (i) Harduagarj 540    (ii) Obra 550

12. West Bengal (i) Santaldih 480    (ii) Chandrapur 420    (iii) Bander 330

Hydro Power Plants in India:Sr. No. State Name of power Plant Location River Capacity (MW)

1 Gujarat Ukai (4X 75, 2X2.5) Tapi 305    Kadana (4X 60, 2X1) Mahi 242

2 Maharashtra Koyna Koyna 860

3 Rajasthan Dehar Beas.Satluj 990    Bhakra Right bank Sat I tij 770

    Bliakra Left Bank Satluj 540

    Rana Pratap Saczar Chamba I 172

4 Andhra Pradesh Nagarjuna Sagar Krishna 810

    Srisailam Krishna 770    Lower silem Godavari 460    Upper silem Godavari 240    Machkund Mach kund 115

5 Jammu & Kashmir Salal Chenab 690

6 Punjab Ranjit Sagar Ranj it 600

    Mukerian Beas 207

8 Orissa Upper Indravati lndravati 600    Balimela Machukund 360    Upper Kolab Kolab 320    Hirakund Mahanadi 3059 Madhya Pradesh Bansagar Sone 315    Pench Narmada 160    Ghandhi Sagar Chambal 115

10 Karnataka Kalinacii Nagjhari Kalinadi 840    Varahi Varahi 230    Gerusuppa Sharvathi 180    Kodasalli Kalinadi 120

11 Tamil Nadu Kunclah Kundah 555

    Kadampari Cauvery 400

    Kodiyar Kodiyar 100

Cont…Sr. No. State Name of power

Plant Location River

Capacity (MW)

12 Kerala Idduki Idduki 780

    Sabarigiri Pamba 300

    Kuttiadi Kuttiadi 125

13 Uttaranchal Chibro Yam una 240

    Ramganga Ramganga 196

    Chilla Ganga 144

    Tanakpur Sarda 120

14 Manipur Loktak Leimatak 105

15Meghalaya Umiam Umiam 114

Pressurized Water Reactor (PWR) :

Cont…• Enriched Uranium as Fuel• Water is used as coolant & moderator• The water in the primary circuit gets heated by absorbing

the fission energy in the reactor core & same energy is given in the heat exchanger to generate the steam.

• The water coming out of the heat exchanger is circulated by the pump to maintain the pressure in the circuit in the range of 100 to 130 atm.

• The water becomes radioactive when passing through the reactor ; therefore entire primary circuit including heat exchanger must be shielded to protect the operating persons.

• The electrical generator coupled with steam turbine generates electrical power.

Advantages:1) The water which is used as coolant, moderator and reflector is

cheap & easily available.2) Requirement of control rods are less.3) Secondary circuit is not affected by radiation, so normal

turbine maintenance technique can be used.4) Operation is safe & stable.

Disadvantages:1) High primary circuit pressure requires strong pressure vessel.2) High capital cost.3) Corrosion problem.

Boiling Water Reactor(BWR) :• Enriched Uranium is used as

fuel and water is used as coolant.

• In this type of reactor steam is generated in reactor core itself & this steam is expanded in turbine.

• After expansion steam is condensed in condenser. Feed pump is used to circulate water back into reactor core.

Advantages:1) The pressure inside the reactor vessel is considerably smaller

than P.W.R.2) The metal surface temperature is lower than P.W.R.3) The boiling water reactor (B.W.R.) is more stable than any

other type of reactor.4) The thermal efficiency of this reactor is 30 %.

Disadvantages:1) The steam leaving the reactor is slightly radioactive therefore,

light shielding of turbine and piping is necessary.2) More safety precautions needed which are costly.

CANDU Reactor:

• The long form of CANDU is Canadian Deuterium Uranium.• Natural Uranium is used as fuel and heavy water as moderator.

Advantages:1) No control rods are required, so control is much easier.2) Enriched fuel is not required.3) A short time is needed to construct the reactor compared with

P.W.R. and B.W.R.4) Heavy water being good moderator.

Disadvantages:1) The cost of heavy water is extremely high.2) The leakage is major problem.3) Very high standard of design, manufacture, inspection and

maintenance are required