1. IDEAL REGENERATIVE RANKINE CYCLE
• IT RAISES THE TEMPERATURE OF WATER LEAVING
THE PUMP (FEED WATER) BEFORE IT IS FED TO
BOILER.
• EXTRACTING OR BLEEDING STEAM FROM
TURBINE AT A POINT. THIS STEAM WHICH COULD
BE USED TO PRODUCE MORE WORK BY
EXPANSION IN TURBINE IS USED TO HEAT FEED
WATER INSTEAD. THE DEVICE WHERE THE FEED
WATER IS HEATED BY REGENRATION IS CALLED
REGENERATOT OR FWH.

2. IDEAL REGENRATIVE RANKINE CYCLE
• IT IMPROVES THE THERMAL EFFICIENCY OF POWER
PLANT.
• IT PREVENTS DEAREATING- HEATER AT HIGHER
PRESSURE THAN ATMOSPHERIC. IT REMOVES ANY
DISSOLVED GASES, PARTICULARLY O2 FROM WATER
BEFORE IT IS FED INTO BOILER
• IT IS OPEN OR DIRECT AND CLOSED FWH.
• FWH IS A HEAT EXCHANGER WHERE HEAT IS
TRANSFERRED FROM THE STEAM TO THE FEED WATER
EITHER BY MIXING THE TWO FLUID STREAMS OR
WITHOUT MIXING THEM.
• ADDL BENEFITS----------

3. OPEN WATER & CLOSE WATER HEATER

4. BENEFITS OF REGENERATION
• STEAM FLOW TO CONDENSOR ARE REDUCED
HENCE;
• SMALLER CONDENSOR AND BOILER
• DIFFICULTY OF PASSING LARGE VOLUME OF
STEAM THROUGH THE LAST STAGES IN TURBINE
IS LESSENED.
• INCREASED BLADE HEIGHTS TO ACCOMMODATE
THE INITIAL STEAM CONSUMPTIONS
• TURBINE LESS EXPOSED TO EROSION.

5. COMPARISON OF REGENRATIVE WITH
REHEAT
• REHEAT LARGE AND LONG PIPES ARE NEEDED WHICH
MEANS EXTRA COST.
• LARGE PRESSURE DROPS OCCURS IN THE PIPING.
• PROVISION FOR EXPANSION AND CONTRACTION OF
PIPES JOINTS IS TO BE MADE..
• REHEAT IS COMPLICATED SYSTEM AS…
• DETERMINATION OF SUITABLE REHEAT PRESSURE
LEVEL IS PROBLEM AND ENTAILS NO OF
CONSIDERATIONS
• LOW HEAT INPUT HENCE LOWER EFFICIENCY IN
REHEAT

7. v

8. NUMERICAL/ASSIGNMENT NO 3
• CONSIDER A REGENRATIVE VAPOUR POWER CYCLE WITH
ONE FEED WATER HEATER. STEAM ENTERS THE TURBINE AT
8 MPa, 480° C AND EXPANDS TO .7 MPa, WHERE SOME OF
THE STEAM IS EXTRACTED AND DIVERTED TO THE OPEN
FEED WATER HEATER OPERATING AT .7 MPa. THE
REMAINING STEAM EXPANDS THROUGH THE SECOND
STAGE TURBINE TO THE CONDENSOR PRESSURE OF .008
MPa. SATURATED LIQUID EXISTS THE OPEN FEED WATER
HEATER AT .7 MPa.ISENTROPIC EFFICIENCY OF EACH
TURBINE STAGE IS 85 % AND EACH PP OPERATES
ISENTROPICALLY. IF THE NET POWER OUTPUT OF THE CYCLE
IS 100 MW, DETERMINE. A. thermal efficiency B. mass flow
rate of steam entering the first turbine stage in kg/h.

9. NUMERICAL/ ASSIGNMENT 4
• STEAM IS WORKING FLUID IN AN IDEAL RANKINE CYCLE
WITH SUPERHEAT AND REHEAT.STEAM ENTERS THE
FIRST STAGE TURBINE AT 8 Mpa 480 CELSIUS AND
EXPAND TO .7 Mpa. IT IS THEN REHEATED TO 440
CELSIUS BEFORE ENTERING THE SECOND STAGE
TURBINE, WHERE IT EXPANDS TO THE CONDENSOR
PRESSURE OF .008 Kpa. THE NET POWER OUTPUT IS
100 MW. DETERMINE
• THERMAL EFFICIENCY 2.MASS FLOW RATE OF THE
STEAM IN KG/H 3. RATE OF HEAT TRANSFER FROM THE
CONDENSING CYCLE AS IT PASSES THROUGH THE
CONDENSOR IN MW. DISCUSS THE EFFECT OF REHEAT
ON THE VAPOUR POWER CYCLE?