Energy Conversion

Course Description

Energy transformations and energy processes in systems of thermal power plants, nuclear power plants, hydropower plants and newer (advanced) energy systems for production of electrical energy. The conversion of chemical energy, nuclear energy, the potential and kinetic energy in water, and wind energy to (mechanical) work. Analysis of energy processes in power plants. Improvements in processes: second law analysis of systems (exergy analyses). Nonconventional processes of electrical energy production and direct processes of energy conversion into electricity.

General Competencies

Explain the regularities governing processes of energy conversion in generating parts of electric power system and get acquainted with nonconventional, direct and newer processes of energy conversion into electricity.

Learning Outcomes

  1. explain the classification of energy forms in accord with the possibility of accumulation and transformation into (mechanical) work (exergy or availability) as well as the differences among different thermodynamic systems and control volumes
  2. explain the applications of conservation laws of mass, energy, linear and angular momentum conservation, law of increase in entropy and equations of fluid states in analysis of energy conversions in electric power systems
  3. analyze fluid flow, types of fluid flow, forces and mathematical models of fluid flow
  4. calculate forces on hydroelectric power plants plane and curved surfaces submerged in an incompressible fluid
  5. analyze energy relations in turbines: power and energy equations
  6. analyze processes in hydroelectric power plants and cycles in thermal and nuclear power plants
  7. evaluate efficiencies (energy and exergy) of energy processes in the systems of thermal power plants, nuclear power plants and hydroelectric power plants
  8. evaluate procedures of efficiencies increasing of energy processes in electric power systems

Forms of Teaching

Lectures

Teaching the course is organized in two teaching cycles. The first cycle contains seven weeks, mid-term exam, and the second cycle contains six weeks of classes and a final exam. Classes are conducted through a total of 15 weeks with weekly load of 3 hours.

Exams

weekly

Exercises

Solved examples to support lectures and prepare students for exams. 1 hour per week. Solved examples on slides and discussion of possible variations in problem statement with examples on bord.

Consultations

weekly

E-learning

homework assignments

Grading Method

Continuous Assessment Exam
Type Threshold Percent of Grade Threshold Percent of Grade
Quizzes 0 % 5 % 0 % 5 %
Mid Term Exam: Written 0 % 40 % 0 %
Final Exam: Written 0 % 45 %
Final Exam: Oral 10 %
Exam: Written 0 % 85 %
Exam: Oral 10 %

Week by Week Schedule

  1. Classification of energy forms in accord with the possibility of accumulation and transformation into (mechanical) work (exergy or availability). Definitions of (thermodynamic) systems. Thermodynamic system and control volume. Thermodynamic definition of work. Work of a closed systems. Frictional energy (work). Internally reversible mechanical process. Application of the first law of thermodynamics: energy equations for work of closed systems. Application of the law of conservation of energy to a closed system: internal (thermal) energy and heat transfer. Definition of heat. Energy relation among work of a closed system, internal energy and heat: the first law of thermodynamics for closed systems.
  2. Energy processes in the systems and subsystems of thermal power plants, nuclear power plants and hydro electric power plants: the role of fluids which take over energy, store it, transfer it, transform it, and deliver it to other subsystems. Definition of a fluid. Types of fluids. Thermodynamics and mechanics of fluids. Forces, types of forces, stresses in real and ideal fluids.
  3. Definition of the specific fluid pressure (stress at a point). Stress at a point for a stationary fluid and for nonviscous (inviscid) flows. Conditions of equilibrium of an ideal fluid and stationary real fluid. Pressure distribution in an incompressible static fluid exerted to the force of gravity. Effect of surface force on a fluid confined so as to remain static: Pascal law. Hydrostatic force on a plane surface submerged in a static incompressible fluid. Hydrostatic force on curved submerged surfaces. Law of buoyancy: Archimedes law. Resting of a fluid in noninertial spaces. Centrifuging.
  4. Fluid flow, forces, types of fluid flow and mathematical models of fluid flow. Basic fluid flow dynamic equation (the linear momentum equation for the individual volume). Lagrangian and Eulerian flow description. The total derivative. Flow equation for incompressible, inviscid fluid. Integral Flow equation for real fluid (viscous fluid): the Navier and Stokes-Navier equation. Flow of ideal fluid exerted to the force of gravity: Euler and Bernoulli flow equation. Flow in closed conduits and open channels.
  5. The ideal gas. Boyle - Mariotte law. Gay-Lussac law. Charles law. Equation of state of an ideal gas. The gas constant. Avogadro law. Universal gas constant. Joule law. Internal (thermal) energy of an ideal gas. Specific heat. Processes with ideal gases. Thermodynamics properties of pure substances. Phase change. Two-phase systems. Saturation and quality. Superheated vapor. Cycles. Closed system cycle. Application of the first law of thermodynamics to cycles. Cycles and reversed cycles. Open systems cycle. Sameness of cycles. “Mathematical” prove of imperativeness of two heat reservoirs.
  6. Thermal efficiency. Typical cycles (the Carnot, Joule, Otto and Diesel cycle) and their applications: thermal power plants with steam and gas turbines, nuclear power plants, internal combustion engines, jet engines, refrigeration cycles and heat pumps. Combustion. Chemistry of combustion. Combustion processes. Origin of nuclear energy, mass defect and binding energy. Fission and distribution of released energy. Fusion and energy released during fusion reaction.
  7. Neutron cross sections and reaction rates. Chain reaction and reactor criticality. Power density and spatial distribution of power in reactor core. Radioactivity and decay heat. The nonimplementability of a cycle which would transform constantly all available heat into work. The second law of thermodynamics. Reservoirs, heat engines, and refrigerators.
  8. Exams
  9. Exams
  10. Statement of the second law. Perpetual motion machines. Reversibility and irreversibility. Entropy. Entropy as a property. The combined first and second law. Entropy change of a fluid. T-s diagram. The principle of increase in entropy for a closed system: loss of exergy. Expressions for the exergy of heat energy, a closed system (internal energy), and an open system (enthalpy). Equivalence between mechanical energy forms and exergy. Exergy consumption and entropy generation. Exergy of combustion.
  11. Control volume analysis. Integral form of mass conservation for inertial and noninertial control volume (an open system). Reynold transport theorem. Differential form of mass conservation. The linear momentum equation for inertial and noninertial control volume. Use of the linear momentum equation for inertial and noninertial control volume.
  12. Moment-of-momentum (angular momentum) equation for inertial and noninertial control volume. The first law of thermodynamics as a rate equation. The first law of thermodynamics for a control volume. The steady-state, steady-flow processes. The uniform-state, uniform-flow processes.
  13. The second law of thermodynamics for a control volume. The steady-state, steady-flow process the uniform-state, uniform-flow process. The reversible steady-state, steady-flow process. Principle of the increase of entropy for a control volume. Efficiency. Reversible work. Irreversibility. Exergy (availability).
  14. Thermodynamics of heat engine cycles: power cycles and heat pump. Ideal heat engine cycles. Performance criteria for heat engines. Procedures for heat engine cycles analysis. Vapor power cycles. Thermodynamic analysis of the basic Rankine cycle. Modifications to the basic Rankine cycle: effect of pressure and temperature on the Rankine cycle, the reheat cycle, the regenerative cycle, cogeneration. Deviation of actual cycles from ideal cycles.
  15. Gas (turbine) power cycles. Modification to the basic gas turbine cycle. Combined cycles. Internal combustion motors. Steam, gas and water turbines. Reaction and impulse steam (gas) turbines. Axial-flow turbines. Radial-flow turbines. Francis, Kaplan and Pelton turbines. Energy relations in turbines (equations of turbomachinery): moment-of-momentum equation applied to turbines (water, steam and gas turbines). Performance of turbines. Nonconventional processes of electrical energy production and direct processes of energy conversion into electricity.

Study Programmes

University graduate
Electrical Power Engineering (profile)
Theoretical Course (1. semester)

Literature

POŽAR, H. (1992.), Osnove energetike, 1, 2. i 3. dio, Školska knjiga, Zagreb
White, F.M. (2010.), Fluid Mechanics, McGraw-Hill
Mikuličić, V.; Šimić, Z. (2011.), Energijske pretvorbe (Tekst, http://www.fer.hr/predmet/enepre),

Exercises

General

ID 127408
  Winter semester
5 ECTS
L1 English Level
L1 e-Learning
45 Lectures
15 Exercises
0 Laboratory exercises
0 Project laboratory

Grading System

90 Excellent
75 Very Good
60 Good
50 Acceptable