Thermodynamics Lecture I
Download as PPTX, PDF0 likes209 views
This document provides an introduction to thermodynamics II, covering several key concepts: - It defines different types of energy including kinetic, gravitational, chemical, nuclear, elastic, thermal, and electric energy. - It introduces the first law of thermodynamics regarding heat, work, and internal energy in closed and open systems. - It discusses two-phase systems and using steam tables to find properties like specific volume and entropy at various temperatures and pressures. - It covers the second law of thermodynamics regarding heat engines and the Kelvin-Planck and Clausius statements on entropy and the impossibility of converting heat fully into work in a cyclic process.
Thermodynamics Lecture I
- 3. Energy • Kinetic Energy is found in movement • GRAVITATIONAL • CHEMICAL • NUCLEAR • ELASTIC • MOTION • THERMAL ENERGY AND TEMPERATURE • Electric
- 4. Energy in thermodynamics • Heat, Work and Internal energy (1st Law of thermodynamics) • Close (heat and work) and open system (mass, heat and work) For open system, add flow work, h = u + pv
- 6. Steam Tables • Subcooled, saturated and superheated. • At T = 220 oC, specific volume of liquid = 0.001194 m3/Kg and specific volume of sat vapour = 0.086094 m3/Kg. • At T = 220 oC and x (quality) = 0.325, specific volume: v = vf + x vfg = 0.001190 + 0.325 * 0.086094 = 0.02917 • Other variables : v, u, h, s
- 7. Interpolation for Intermediate Properties • You may need double interpolation Slope of line
- 8. Super Heated Table • At 75 oC, find entropy s. From table Temperature Entropy S 50 (X1) 8.1488 (Y1) 75 (X) Y = ? 100 (X2) 8.1741 (Y2) 𝑆𝑙𝑜𝑝𝑒 = 𝑌2 − 𝑌1 𝑋2 − 𝑋1 = 8.1741 − 8.1488 100 − 50 = 0.000506 Y= 𝑌1 + 𝑆𝑙𝑜𝑝𝑒 × 𝑋 − 𝑋1 Y= 8.1488 + 0.000506 × 75 − 50 =8.16145 𝑠𝑜 𝑎𝑡 𝑡𝑒𝑚𝑝𝑟𝑎𝑡𝑢𝑟𝑒, 𝑇 = 75 𝑜 𝐶, 𝐸𝑛𝑡𝑜𝑝𝑦 𝑆 = 8.16145 𝑘𝐽 𝑘𝑔. 𝐾
- 9. Heat Engine and Second Law of Thermodynamics
- 10. Second Law of Thermodynamics • Kelvin Planck Statement
- 11. Second Law of Thermodynamics • Clausius statement
- 12. Entropy • Disorder of system • Friction, heat transfer and non equilibrium process PV and TS diagrams?
- 13. Work done during process or cycle Polytypic process What about the adiabatic process?
- 14. Work done during process or cycle Isothermal process
- 15. Some Important Formulae PV n= constant M= 28.97 g/mol, therefore Ra = 0.287 kJ/kg.K 𝑄 = 𝑚𝐶 𝑝∆𝑇 𝑄 = 𝑚𝐶𝑣∆𝑇
- 16. Extra