Course detail
Combustion Devices and Air Protection
FSI-FSE Acad. year: 2027/2028 Summer semester
The course deals with fuels, combustion and combustion equipment and their impact on the environment. It is divided into three thematic blocks.
The first block is devoted to fuels and combustion. It covers solid, liquid and gaseous fuels, including biomass and waste, their properties and analyses, combustion statics and stoichiometry (calculation of air and flue gas quantities, influence of excess air), and the heat balance of a boiler, its losses and efficiency.
The second block deals with boilers and burners. It includes an overview of grate, fluidized bed and pulverized fuel boilers, burners for solid, liquid and gaseous fuels, the basic arrangement of a steam boiler, and waste heat boilers.
The third block is devoted to combustion emissions and their impact on the environment, the principles of their formation and technologies for their reduction, in particular the separation of particulate matter, desulphurization and the reduction of nitrogen oxide emissions. In the exercises, students practise calculations related to the subject matter covered.
Language of instruction
Czech
Number of ECTS credits
4
Supervisor
Department
Entry knowledge
Students are able to work with basic state variables (pressure, temperature, volume, density) and the ideal gas equation of state, including the conversion of gas volume to standard conditions. They are able to apply the first law of thermodynamics to simple systems, determine heat using specific heat capacity and enthalpy, and work with gas mixtures (mass and volume fractions). In the field of heat and mass transfer, they are able to describe and calculate basic cases of heat transfer by conduction, convection and radiation. From secondary school chemistry, they are able to write and balance a chemical equation, work with the amount of substance, molar mass and molar volume of a gas, and determine the quantities of reactants and products of a reaction from the equation.
Rules for evaluation and completion of the course
The course is completed with a course-unit credit and an exam. Attendance at lectures is optional. Attendance at exercises is compulsory and is checked by the exercise supervisor. One absence is permitted; any further excused absence must be made up by arrangement with the exercise supervisor. The course-unit credit is awarded for attendance at the exercises and for passing the credit test, i.e. obtaining at least 50 % of the points. The test may be retaken once. The points from the credit test do not count towards the final grade.
The exam consists of a written and an oral part. The written part contains 4 equally weighted blocks, each worth max. 25 points, i.e. max. 100 points in total. The first block consists of 5 short questions to be answered in 1–2 sentences (each worth max. 5 points); the other three blocks are more extensive questions. Students who obtain at least 50 points in the written part proceed to the oral part. The oral part verifies whether the student understands the essence of the subject matter and is able to explain it; it is assessed on a scale of 0–100 points.
The overall exam result is calculated as a weighted average: 70 % of the points from the written part and 30 % of the points from the oral part. If the student obtains fewer than 50 points in the oral part, the exam is graded F regardless of the result of the written part. The final grade corresponds to the ECTS grading scale according to Art. 14 of the BUT Rules for Studies and Examinations: A 90–100, B 80–89, C 70–79, D 60–69, E 50–59, F 0–49 points.
4 credits correspond to 104 hours of student workload (1 credit = 26 h): lectures 39 h, exercises 13 h, continuous self-study 20 h, credit test preparation 12 h, exam preparation 20 h.
Aims
Students who complete the course are able to:
- describe the types and properties of solid, liquid and gaseous fuels and convert the fuel composition between individual states,
- perform a stoichiometric combustion calculation, i.e. determine the quantities of combustion air and flue gas and the excess air ratio,
- formulate the heat balance of a boiler and determine its losses and efficiency by both the direct and the indirect method,
- describe the principle and design of grate, fluidized bed and pulverized fuel boilers, burners and waste heat boilers and compare their use according to the type of fuel,
- explain the formation of the main combustion emissions (particulate matter, sulphur oxides, nitrogen oxides, carbon oxides) and their impact on the environment,
- explain the principles of emission reduction technologies, select a suitable technology for given conditions and perform a basic calculation of a separation device.
Study aids
The following study materials are available to students in the course’s e-learning:
- lecture presentations covering all topics of the syllabus,
- tables and diagrams needed for the calculations, in particular the properties of fuels, air and flue gas.
The study programmes with the given course
Programme B-ENE-P: Energy, Bachelor's, compulsory
Type of course unit
Lecture
39 hours, optionally
Syllabus
1. Introduction to the course. Energy and its transformation, basic concepts. Solid fuels – classification, biomass and waste.
2. Solid fuels – fuel analyses, conversion between states, water and ash in fuel, ash properties. Liquid fuels – types and properties. Gaseous fuels – types, properties, gas interchangeability.
3. Combustion statics and stoichiometry – calculation of air and flue gas quantities, excess air, incomplete combustion.
4. Heat balance of a boiler, boiler losses, thermal efficiency – direct and indirect method.
5. Combustion emissions – classification of pollutants, their formation and effects on living organisms and the environment.
6. Steam boiler – classification, arrangement of heat transfer surfaces, feedwater system, economizer, evaporator, superheater.
7. Grate boilers – parts of the furnace, types of grates, combustion on a grate. Fluidized bed boilers – fluidized bed, bubbling and circulating fluidized bed.
8. Pulverized fuel boilers – pulverized fuel, dry-bottom, slag-tap and cyclone furnaces. Waste heat boilers (HRSG).
9. Particulate matter – particle properties, measurement, separation methods (settling chambers, cyclones, electrostatic precipitators, filters). 10. Burners – requirements, burners for solid, liquid and gaseous fuels, combined burners.
11. Desulphurization – formation and effects of SO₂, desulphurization sorbents, wet and dry limestone method.
12. Reduction of nitrogen oxide emissions – NOₓ formation mechanisms, primary and secondary measures.
13. Summary and revision of the course material.
Exercise
13 hours, compulsory
Syllabus
Exercises (6 × 2 h every two weeks, groups alternate in even and odd weeks; in week 13, a 1-hour credit test for both groups)
1. Basic fuel properties – proximate analysis, empirical formulas for the calorific value. Revision of secondary school chemistry: basic concepts, conversions between mass and volume percentages.
2. Stoichiometric calculations for solid fuels – equations of complete and incomplete combustion, calculation of combustion air and flue gas quantities.
3. Stoichiometric calculations for gaseous fuels – design of the flue gas duct diameter of a natural gas boiler for combustion with a given excess air.
4. Boiler efficiency and losses – calculation of efficiency by the direct and indirect method, empirical formulas for boiler losses, calculation of fuel consumption from a given efficiency.
5. Emissions – conversions of concentrations between mass and volume units, comparison with emission limits. Calculation of the amount of a pollutant in flue gas from the fuel composition, conversion of concentration to an emission factor.
6. Emission reduction – flue gas desulphurization using calcium-based sorbents, capture of particulate matter using electrostatic precipitators, gravity separators and filters. 7. Credit test (week 13, both groups together).