Thermodynamics 101 Valparaiso University（热力学101年瓦尔帕莱索大学）.pdf

Thermodynamics 10-1 Single-Component Systems Definitions: Intensive properties: independent of system mass Extensive properties: proportional to system mass Specific properties: extensive properties divided by mass Example (FEIM): Which of the following is an extensive property? (A) temperature (B) weight (C) composition (D) pressure Weight is dependent on the amount of material, so it is extensive. Therefore, (B) is correct. Professional Publications, Inc. FERC Thermodynamics 10-2a Single-Component Systems—State Functions F • Pressure: P = lim A0 A • Temperature: • Specific Volume: ! • Internal Energy: • Enthalpy: Example (FEIM): Steam at pressure 48 kPa and 167K has a specific volume of 0.40 3 m /kg and a specific enthalpy of 29 000 J/kg. Find the internal energy per kilogram of steam. h = u + P J $ m3 u = h # P = 29 000 # 48 000 Pa 0.40 )= 9800 J/kg ( ) kg % kg ( Professional Publications, Inc. FERC Thermodynamics 10-2b Single-Component Systems—State Functions Q • Entropy: S = (constant temperature processes) T 0 • Gibbs’ Free Energy: • Helmholtz Free Energy: