ESO201A: Thermodynamics

Transcription

1 ESO201A: Thermodynamics Instructor: Sameer Khandekar First Semester: Lecture #1: Course File Introduction to Thermodynamics, Importance, Definitions Continuum, System: closed, open and isolated, Boundary: real and imaginary, Control mass and control volume, Properties of a system, State of a system, Equilibrium: Mechanical, Thermal, Chemical, Phase equilibrium, Quasi-equilibrium process, Continuum Thermodynamics, Simple-compressible and complex systems, The State Postulate Lecture #2 Overview of 2-stroke, 4-stroke and Wankel engine (To highlight unsteady and non-uniform processes), Intensive and Extensive properties, Concept of temperature from Zeroth law of thermodynamics, Linear dependence of temperature on pressure for constant volume gas thermometers, temperature as a manifestation of kinetic energy, absolute thermodynamic scale of temperature - Kelvin scale, Other scales, Overview of temperature, measuring devices:-liquid crystal sheet, RTD, infrared thermography, thermocouples, mercury thermometers, Pressure measurement - absolute and gauge pressure, piezoelectric transducer, manometer, Pascal s law, hydrostatic law, Barometer. Lecture #3 Classification of Energy-mechanical, electrical, chemical, thermal, nuclear, magnetic etc., Microscopic and Macroscopic forms, Internal energy, Macroscopic - kinetic, gravitational potential, Flow work, Mechanical forms of energy, Microscopic - translational, rotational and vibrational energies of atoms and molecules, electronic translational, rotational and spin, Chemical bond energy, Nuclear energy, Interactions in Open and Closed Systems, Latent and specific heat, manifestation of heat energy into either temperature or in other microscopic forms of energy. Lecture #4 Heat and Work interactions, Different processes-adiabatic, isothermal, isobaric, isochoric, Sign convention for heat and work, Similarities between heat and work, Point and Path functions, Mechanical form of work-displacement work, shaft work, surface tension work, spring work, stretching work, nonmechanical forms of work-electrical work, magnetic work, generalized expression for work done. Lecture #5 Overview of Energy conversion systems Examples (on PPT) jet engine, marine engine, roots blower, engine turbocharger, Pelton wheel etc., Introduction to First law of thermodynamics, Concept of Total energy and its change, Work done in an adiabatic process, Work done and energy change in a cyclic process, Thermodynamic efficiency of a sub-system and total efficiency of a system, Highlighting the connection between Energy and Environment.

2 Lecture #6 Definition of pure substance, phases: solids liquid and gases, principal phase and sub-phases, Demonstration of mechanical boiling, Introduction to phase diagrams, T-v diagram, Saturation pressure and saturation temperature, Sensible heating, Latent heat of vaporization, Compressed or sub-cooled liquid, Saturated liquid, Saturated and superheated vapor, Critical temperature, pressure and volume, Maintaining isothermal conditions for a system. Lecture #7 (On PPT) Phase diagrams and tables, PV, TV and PT diagrams, P-V-T surfaces (for substances which expand and contract on freezing, respectively), Reading phase diagrams, latent heat of fusion and evaporation, triple point, concept of regelation, allotropic forms of solid phases, Boyles law, Charles law for gas phases, Introduction to Property Tables, Enthalpy as a combination property. Lecture #8 Introduction to supercritical fluids, Phase diagram of CO 2, H 2O, Properties of wet mixture, dryness fraction or quality, locating a mixture on 2-phase diagram, Formulation of mixture properties, iso-quality lines on 2-phase diagrams, quality as a thermodynamic property inside the 2-phase dome, reading property data from superheated vapor, 2-phase region and compressed liquid table, characteristics of superheated vapor and compressed liquids, 2 example problems Lecture #9 Ideal Gas law and its validity, reasons of deviation from ideal gas behavior, van der Waals correction for pressure and volume, Estimation of constants a and b using critical point data, Beattie-Bridgeman equation, Benedict Webb- Ruben Equation, Virial equation, (On PPT) - solution of van der Waals equation of state, Comparison of percentage errors for different equations of state, Use of Ideal gas equation with compressibility chart. Lecture #10 Limitations of van der Waals equation, Introduction to metastable states, reduced pressure and temperature, generalized compressibility chart, Principle of corresponding states, 3 example problems on the use of charts and tables Lecture #11 First law applied to a closed system, Moving boundary work, boundary work done in different quasi-equilibrium processes -isobaric, isochoric, isothermal and polytropic processes, example problem involving shaft work, friction work and spring work, (On PPT) Pistons in different IC engine configurations. Lecture #12 Introduction to heat capacity, Expression for heat addition at constant pressure and constant volume, Calculation of u, h, C p, C v for an ideal gas, Relation between Cp and Cv for an ideal gas, heat capacity for solids and liquids. Lecture #13 Specific Heat Ratio for mono-atomic, di-atomic and polyatomic gases, adiabatic process for an ideal gas for a simple compressible system, Comparison of compression work done in adiabatic and isothermal processes, Slope of adiabatic and isothermal processes on P_V diagram, Constant internal energy process, (On

3 PPT) Different types of compressors-air cooled, water cooled, 2-stage etc., one example problem. Lecture #14 First law applied to an open system, comparison of control mass and control volume approach, conservation of mass principle applied to an open system, steady and unsteady system, Incompressible system, Concept of flow work. Lecture #15 Derivation of energy equation for control volume, Examples of typical engineering systems, Turbines, Compressors, Heat Exchangers, Pipe flow, pumps. Lecture #16 Completion of discussion on steady flow processes, Mixing, Isenthalpic process, Joule-Thompson effect (only introduce), Discussion of Quiz #1, two example problems of Chapter 4. Lecture #17 Unsteady Control Volume Processes, Charging and discharging of gas cylinders, need for second law of thermodynamics, discussion on quality of energy, thermal efficiency and level of perfection of thermodynamic systems, concept of thermal source and sink, block diagram of a typical thermal power plant to illustrate second law. Lecture #18 Need of heat rejection in a cyclic process, Clausius and Kelvin-Planck, statements of second law of thermodynamics, Efficiency analysis of a thermal power plant and a refrigeration cycle, coefficient of performance for refrigerator and heat pump cycle, equivalence of Kelvin-Planck and Clausius statements. Lecture #19 Reversible and irreversible processes, internal, external and totally reversible processes and their examples, internally reversible iso-thermal process, heat transfer processes, The Carnot s heat engine cycle. Lecture #20 Carnot cycle implications, The Carnot principles, Thermodynamic temperature scale, Thermal efficiency of a reversible engine as a function of high and low temperature reservoirs and its functional form, Kelvin scale of temperature or absolute temperature scale, proof of Q_add/Q_rej = T_H/T_L Lecture #21 Clausius inequality its validity, Proof and implications, the increase of entropy principle. Lecture #22 Entropy change of a control mass during an irreversible process, entropy generation for reversible and irreversible processes, Entropy change for an isolated system, Discussion on equilibrium states w.r.t. increase of entropy principle MID TERM COMPLETE

4 Lecture #23 Property diagrams involving entropy, TdS relations, T-S diagram, H-S diagram, Representation of Carnot s cycle on T-S, P-V diagram. Entropy change for solid and liquid phases, Entropy change for an Ideal Gas, Isentropic processes for an Ideal Gas. Lecture #24 Entropy change in rate form, entropy balance for control mass and control volume, generalized equation for entropy change in a CV, entropy change and steady flow energy equation for reversible adiabatic process and reversible isothermal process, entropy change for an adiabatic nozzle, Bernoulli's equation derivation. Lecture #25 Isentropic efficiency of steady flow systems - gas turbine, steam turbine, nozzle, detailed analysis of a compressor, comparison of reversible adiabatic and reversible isothermal processes to get an ideal benchmarking process for a compressor, isentropic efficiency of a compressor, use of intercooler in intermediate stages of compression to achieve nearly isothermal process. Lecture #26 Condition for minimum work associated with compression with intercooling, reversible adiabatic and reversible isothermal efficiencies of compressor, Introduction to the concept of exergy or work potential, definitions, dead state, forms of exergy, exergy of kinetic and potential energy. Lecture #27 Exergy, reversible work, useful work, irreversibility (destruction of exergy), second law efficiency, Exergy calculation for a closed system (control mass), example problem, difference between first law and second law efficiency. Lecture #28 Exergy due to flowing mass, ways of increasing exergy of a system (heat, work and mass), exergy balance for a closed system, decrease of exergy principle, exergy of an isolated system for a completely reversible and irreversible system, exergy balance for a closed system. Lecture #29 Exergy balance equations in rate form (Similarities/differences of the functional form with energy conservation and entropy balance equation), Exergy analysis for a control volume and for a steady flow system, exergy destruction expression for an isentropic turbine, adiabatic nozzle and compressor, example problem - calculation of rate of entropy generation and rate of exergy destruction associated with heat transfer, system and extended system, second law efficiency (exergy based) of turbines and compressors. Lecture #30 Thermodynamic analysis of combustion, Conventional and non-conventional fuels, complete and incomplete combustion, stoichiometric analysis, air/fuel ratio, relative air/fuel ratio, equivalence ratio, constant volume and constant pressure combustion, heat of reaction at constant volume and constant pressure.

5 Lecture #31 Concept of higher and lower heating/calorific value, reference state for energy calculations, internal energy/enthalpy vs. temperature graph for reactants and products, Adiabatic flame temperature of fuel, concept of formation reaction, heat of formation, standard heat of formation, the net enthalpy of a substance relative to a standard state. Lecture #32 Introduction to thermodynamic power cycles, classification, gas power cycles, heat addition and rejection at constant temperature and pressure, characteristics of fuel (gasoline and diesel), operation of a typical four stroke engine, Limitations of Carnot cycle for real-time engineering systems, Lecture #33 Analysis of Otto and diesel cycles and derivation of thermal efficiencies, compression ratio and cut-off ratio, concept of relative efficiency, analysis of dual cycle (as homework), Real cycles and some brief differences, Solved problem. Lecture #34 Vapor Power cycles, Carnot cycle and its limitations, Modified Carnot cycle or Rankine cycle, Detailed analysis of components of Rankine cycle, heat input, work output and thermal efficiency of a Rankine cycle, ways to improve thermal efficiency and network output from a Rankine cycle and their limitations-by increasing boiler pressure or lowering of condenser pressure, Reheating or turbine staging, super critical boilers. Lecture #35 Actual Rankine cycle, isentropic pump and turbine efficiencies, pressure drops in a typical power plant, ways to improve thermal efficiency, reheat and regeneration processes as a means of improving thermal efficiency of a plant, detailed analysis of regeneration, numerical problem on steam power plant with reheat. Lecture #36 Discussion on second law of thermodynamics and entropy, Refrigerator and heat pump, the reversed Carnot cycle as refrigeration cycle and its limitations, the reversed Rankine cycle and its limitations, the ideal and actual vapor compression refrigeration cycles, discussion on refrigerants to be used in the refrigeration cycles - ammonia, sulfur di-oxide, Freon 12, R134a, criteria for selecting refrigerants and their limitations. Lecture #37 (Course reaction Survey completed in first 10 minutes) Introduction to Brayton Cycle, Pressure ration, Analysis and thermal efficiency, Gas refrigeration cycle, Reversed Brayton cycle and its COP, example problem on reversed Brayton cycle, Discussion on working fluids and tonnage rating of refrigerators. Lecture #38 Thermodynamic Potentials - Internal energy, Enthalpy, Helmholtz free energy, Gibbs free energy, expressions for U, H, F, G in terms of measurable quantities, derivation of Maxwell equations using properties of partial

6 derivatives and point functions, extraction of primary definition of temperature, pressure and volume from thermodynamic potentials, derivation of Clapeyron and Clausius-Clapeyron equations, slope of P-T diagram. Lecture #39 Generalized relation for change of internal energy, enthalpy and entropy, recovering the ideal gas change relations from the generalized relations, Isothermal compressibility and Volumetric expansivity, Difference between Cp and Cv, Discussion on use of Maxewell equations for generating property tables.