1. Condenser in Power Plants
P M V Subbarao
Professor
Mechanical Engineering Department
I I T Delhi
Equipment to Create an Efficient Closed Cycle Plant …….

2. Most Important Equipment in Watts Engine

3. Pearl Street Station
Thomas Edison in September 1882 achieved his vision of a full-scale central power station

4. Power Plant Condenser

5. Two-Pass Surface Condenser

6. Energy Balance of A Condenser
The temperature rise of cooling water:
6 to 7 degree C for single pass.
7 to 9 degree C for two pass.
10 to 12 degree C for four pass.

7. Air Ingestion into Condensing Steam

8. Thermal Processes Occurring in Condensers
The condenser never receives pure seam from the turbine.
A mixture of steam and non-condensable gases (Air-steam mixture) enters the condenser.
The ratio of the quantity of gas that enters the condenser to the quantity of steam is called the relative air content.
The value of , depends on type, capacity, load and design dimensions of the condenser plant.

9. Variation of Steam-air Mixture Parameters

10. T-S Diagram : Rankine Cycle with Irreversible Condenser

11. Law of Mixtures
Using Dalon’s Law:
Gas laws:

12. Impact of Non-Condensibles
At the entry to condenser the relative content of air is very low and partial pressure of steam is almost equal to condenser pressure.
As air-steam mixture moves in the condenser, steam is condensed and the relative content of air increases.
Accordingly, the partial pressure of steam drops down.
The pressure in the bottom portion of condenser is lower than that of the top portion.
The pressure drop from inlet to exit of condenser is called steam exhaust resistance of a condenser.
The partial pressure of air at the bottom of the condenser cannot be neglected.

13. Condenser with Air Removal Pump : A practicable Concept

14. Combined Condensation & Air Pumping Action:
Air Pumping Action Vs Condensing Action !!!

15. Effect of Air Leakage on Condenser Pressure
Air pump controlling the back pressure
Condenser controlling the back pressure
Inlet Condenser Pressure, mm of Hg
Air pump controlling the back pressure
Condenser controlling the back pressure 10 30 40 50 20
Cooling water Inlet Temperature

16. Power Loss Due to Excess Back Pressure
What is Techno-economically Viable value of TTD ?

17. Condenser Performance
500MW unit condenser overall heat transfer coefficient obtained from the condenser model is 2947 W/m2 oC.
Value of overall heat transfer coefficient provided by the manufacturer is 2907 W/m2 oC.
Thus representing an error of 1.37% in estimated value of overall heat transfer coefficient.

18. Effect of Ambient Temperature & Water Flow Rate
Cooling Water Flow rate: Cumecs C

19. Effect of Ambient Temperature & Water Flow Rate
Cooling Water Flow rate: Cumecs