📖 Appendix 1: Reminders

Essential Recaps on Diagrams and Turbines

• Thermodynamic Diagrams:
  • (h, ln(P)): Mechanical constraints + energy.
  • (T, s): Work visualization (area = work).
  • (h, s) Mollier: Ideal for turbine expansions.
• Turbine Efficiency:
  • Isentropic vs. polytropic (better for multi-stage turbines).
  • Baumann’s Rule: -1% efficiency per steam quality point (e.g., wet steam).
• NTU Method:
  • Heat exchanger calculations (Thermoptim implementation).
• Thermocouplers:
  • Advanced thermal coupling representations.

Takeaway: Graphical and mathematical tools for rigorous yet accessible analysis.

Abstract

This appendix provides essential reminders on technologies and thermodynamic concepts used in steam power plants, necessary for nuclear reactor secondary cycle analysis. The appendix begins with detailed presentation of three thermodynamic property diagrams for pure substances: the enthalpy-pressure (h, ln(P)) diagram combining mechanical constraints with energy variables; the entropy (T, s) diagram enabling direct cycle comparison through area representation of work; and the Mollier (h, s) diagram providing excellent visualization of turbine expansion zones while allowing direct enthalpy measurements. For each diagram, critical points, saturation curves, and characteristic features are explained. Performance characterization of compressors and turbines is addressed through isentropic and polytropic efficiency concepts, with the polytropic approach proving more realistic for multi-stage turbines. Baumann’s rule for expansion efficiency degradation as function of steam quality is presented, showing approximately one percentage point efficiency reduction per quality point decrease. The NTU (Number of Transfer Units) method for heat exchanger calculation is comprehensively reviewed, including practical implementation in Thermoptim software. Thermocouplers are introduced as extensions enabling thermal coupling representation beyond traditional heat exchangers. Mathematical formulations, diagrams, and implementation guidelines provide complete reference material supporting the book’s pedagogical approach while maintaining accessibility for different expertise levels.