Effect of steam bleeding (regenerative feed heating) What is the combined effect of steam bleeding (extraction for feedwater heating) in a Rankine-cycle turbine?

Introduction / Context:
Bleeding (extraction) routes a fraction of expanding steam from intermediate stages to feedwater heaters. This regenerative process improves the average temperature of heat addition in the boiler, raising thermal efficiency, but it also reduces the mass flow continuing to the low-pressure stages, lowering net power.

Given Data / Assumptions:

• Rankine cycle with one or more regenerative feedwater heaters.
• Fixed main steam conditions at the boiler and fixed condenser pressure.
• Negligible pump work relative to turbine work for conceptual discussion.

Concept / Approach:
Raising feedwater temperature reduces the irreversibility of heat addition because heat is supplied at a higher average temperature. This increases cycle efficiency (less fuel per unit power). However, steam diverted to heaters no longer expands through downstream stages, reducing turbine power for the same boiler flow. Practical designs trade efficiency gains against hardware cost and reduced specific output.

Step-by-Step Solution:
Extract steam from an intermediate pressure to a heater; condense it to warm feedwater.Feedwater returns hotter to the boiler, increasing average heat-addition temperature.Because mass flow to later stages is lower, the turbine’s net work decreases.Overall cycle efficiency (net work / heat input) increases despite lower absolute power for a fixed boiler flow.

Verification / Alternative check:
TS-diagrams show reduced area of condenser heat rejection and elevated feedwater line, demonstrating improved thermal efficiency with regeneration.

Why Other Options Are Wrong:
Choosing any single effect ignores the coupled thermodynamic and mass-flow consequences; all listed effects occur together.

Common Pitfalls:
Expecting both higher efficiency and higher specific power; in basic regeneration, specific power usually drops when bleed fraction increases.

Final Answer:
All of the above