ChemE 260 – Thermodynamics：方案260–热力学.doc

ENGR 224 ThermodynamicsTest #1 OutlineSpring 2011Chapter 1 Introduction: Basic Concepts of Thermodynamics 1st & 2nd Laws of Thermodynamics Internal, kinetic and potential energies Dimensions and Units: SI & AE gc F = m a Nomenclatureo Systems: Open vs. Closedo Properties Intensive vs. Extensive Molar and Specific Propertieso State of a systemo Processes and Process Paths Isobaric, Isothermal & Isochoric Thermodynamic Cycleso Equilibrium: Thermal, Chemical, Phase and Mechanicalo Quasi-Equilibrium Process Pressure: Absolute, Gauge and Vacuumo Barometer, Manometer and Differential Manometer Equations Temperature Scales: oC, K, oR, oFo Converting between T scaleso Changes in temperatureChapter 2 Properties of Pure Substances Pure Substances Phases and Phase Changeso Vaporization/Condensation, Melting/Freezing, Sublimation/Desublimation Phase Diagrams: PV, TV & PTo Subcooled Liquid, Saturated Liquid, Saturated Mixture, Saturated Vapor, Superheated Vaporo Tsat and Psat = P*o Saturated Liquid Curve, Saturated Vapor Curve, Two-Phase Envelope, Critical Pointo Isotherms and Isobarso Triple Point Thermodynamic Data Tableso Saturation Temperature Tables and Saturation Pressure Tableso Superheated Vapor Tables and Subcooled Liquid Tableso Linear Interpolationo Double Interpolation Vapor-Liquid Equilibriumo Partial Pressure, Vapor Pressure, Total Pressure, and Mole Fractiono Relative and Absolute Humidityo Boiling vs. Evaporation Equations of State (EOSs)o The Ideal Gas EOS: Always test its validityo Compressibility Factor EOSo Advanced EOSs: Virial, Van der Waals, RK, and SRKChapter 3 Heat Effects U(T,P) and H(T,P): Real Substances, Incompressible Liquids and Ideal Gases Using the NIST Webbook Heat Capacities: Constant Volume and Constant Pressureo Integrate CV to determine DU. Integrate CP to determine DH.o IG CP polynomial = Shomate Equation (NIST Webbook)o IG: CP = CV + Ro Solids & Incompressible Liquids: CP = CV and DU = DH. Hypothetical Process Paths (HPPs)o Break a complicated process into steps in which just one property changeso Change in any property for the entire HPP is the sum of the changes in that property for the steps that make up the HPP.o Latent Heats: Vaporization, Fusion and Sublimation Clapeyron equation DHvap = fxn(dP*/dT) Clausius-Clapeyron Equation Assumes IG and Vsat vap Vsat liq DHvap from slope of LnP* vs. 1/T(K) Antoine Equation P* = fxn(T)Chapter 4 The First Law of Thermodynamics Closed Systems Worko Path variable, inexact differentialo Integral of F dxo Boundary Work: Wb = P dVo Sign Convention: W 0 for work done BY the system ON the surroundingso Quasi-Equilibrium Process: Slow, No Unbalanced Forces P dV is easy to evaluate because the restraining force is just Pbulk x Across of the piston.o Special Processes: Isothermal, Isochoric and Isobaric Easier to evaluate Wb.o Shaft Work very important for open systems, see chapter 5.o Other kinds of work Gravitational and Acceleration Work It is more convenient to express these in terms of change in kinetic and potential energies Spring Work We will usually consider this just another form of boundary work. Heato Energy that moves across the boundary of the system because of a difference in temperature.o Moves spontaneously from hot to cold things.o Sign Convention: Q 0 when heat is transferred from the surroundings into the system.o Adiabatic Processes: Qnet = 0o Path variable, inexact differentialo Mechanisms for Heat Transfer Conduction: Fouriers Law Convection: Newtons Law of Cooling Radiation: Stephan-Boltzmann Law The 1st law of Thermodynamicso Energy cannot be created or destroyed, it can only change formo Integral Form: Q W = DEsys = DU + DEkin + DEpot syso Differential or Rate Form is more useful for open systems (see chapter 5) Problem Solving Procedureo Read Carefully, Draw a Diagram, List Given Info & List Assumptionso Write Equations and Lookup Data then Solve Equationso Verify Assumptions & Answer Questions ! Special Cases of the 1st lawo Isobaric Processes: Q = DHo Isochoric Processes: Q = DU Thermodynamic Cycleso 1st Law: Qcycle = Wcycleo Types of Cycles Heat Engines: Purpose is to convert heat into work Thermal efficiency: hth = fxn(QC, QH) Refrigeration Cycles: Use work input to remove heat from a cold object (and incidentally reject heat to a hot object) Coefficient of Performance: COPR = fxn(QC, QH) Heat Pump: Use work input to add heat to a hot object (and incidentally absorb heat from a cold object) Coefficient of Performance: COPHP = fxn(QC, QH)Chapter 5 1st law Open Systems Mass & Energy Balances on St