Understanding Thermodynamics in Practice — Lesson - 2

This lesson covers the principles of steam turbines and air compressors, focusing on their operation, properties, and the relationship between them. It delves into the specifics of how a steam turbine drives an air compressor, the properties of the air compressor, and the conditions under which the turbine operates. The lesson also explains the concept of polytropic processes, the importance of no liquid at the turbine exit, and the calculation of work output. It further discusses the concept of entropy balance for both the turbine and compressor. An illustrative example is used to explain the calculations involved in determining the exit state, mass flow rate, work delivered, and rate of entropy generation.

Video Highlights

01:46 - Explanation of the polytropic process in the compressor
05:24 - Calculation of the work delivered by the turbine
09:25 - Application of the first law for the turbine
13:56 - Application of the first law for the compressor
17:14 - Calculation of the entropy generated in the compressor

Key Takeaways

- A steam turbine drives an air compressor, and the work output from the turbine is transferred to the air compressor.
- The maximum work output from the turbine is achieved when no liquid is at the turbine's exit.
- The work delivered by the turbine is calculated and then supplied to the compressor.
- The rate of entropy generation in the turbine and compressor is calculated considering the heat loss from both.
- The exit state corresponding to maximum power delivered by the turbine is calculated, and the sign convention is used properly considering the heat loss for the compressor.