Thermodynamics I

Examples  2.25  2.74  2.89

Wrap-up  Heat – work equivalent  Chapter 2 Equations  One-Minute Paper  Test 1: 1/27 Chapter 2 Text – graphs & tables Formula sheet

Chapter 3  to_3_g  Evaluating Properties

Conservation of energy  First law of thermodynamics  Q – W = E  For closed system Q – W = KE + PE + U

System  Isolated  Closed  Open

Process  Isometric  Isothermal  Isobaric  Adiabatic  Polytropic 

Process  Properties  Work & heat  Direction convention

Thermodynamics I  Work F x s Piston/cylinder Shaft work Heat exchanger? Rate of doing work?  Expansion work

Working Fluid  Pure substances Liquid Gas  Properties – determine phase  Property diagrams Compressed liquid Mixture of liquid & vapor Vapor

Property Diagram  Pv,Tv, & Ts useful  Tv Constant pressure heating Liquid Saturated liquid Vaporization – quality Saturated vapor Superheated Critical point

Property diagram  Quality definition  Tables Pressure – saturated Temperature – saturated Specific volume Internal energy Enthalpy Entropy  Interpolation

Property tables  Homework – fill in table

Ideal gas  Ideal gas characteristics  Ideal gas processes  Handout

Polytropic process  Expansion/compression work

Performance  Result/effort expended  Evaluate: degree, location?  What can be done?  Costs of improvements?  Payback?