Closed Feed Water Heaters — Lesson 3

This lesson covers the operation and functionality of open and closed feed water heaters in a Rankine cycle. It explains how these heaters work at different pressures and how they affect the overall performance of the cycle. The lesson also introduces the concept of reheating steam to improve the power output and efficiency of the cycle. It further discusses the practical applications of these concepts in a thermal power plant, including the use of multiple turbines and feed water heaters. The lesson concludes with a comparison of the efficiencies of supercritical and ultra-supercritical power plants.

Video Highlights

01:22 - Explanation of how closed feed water heater operates
06:48 - Explanation of how reheating is incorporated in the cycle
17:25 - Comparison of the performance parameters of different variations of the cycle
28:30 - Discussion on the operation of a supercritical power plant

Key Takeaways

- Open and closed feed water heaters operate at different pressures, with the streams entering and exiting these heaters being managed differently.
- Regenerative feed water heating improves the thermal efficiency of the cycle but reduces the specific work output.
- Reheat stages in practical power plants help to retain the benefits of regenerative feed water heating while addressing its shortcomings.
- Modern power plants typically operate at pressures higher than the critical pressure, with supercritical and ultra-supercritical power plants offering high efficiencies.