Kurzus nemzetközi vendég- és részidős hallgatóknak

Kar

Informatikai Kar

Szervezet

IK-SEK Savaria Műszaki Intézet

Kód

SBANGP6131EN

Cím

Heat Engines

Tervezett félév

Tavaszi

ECTS

4

Nyelv

en

Leírás

The subject, first, further extends the students’ knowledge in thermodynamics and fluid mechanics to the special field of compressible fluid flow (either gas or steam). Based on this new knowledge and that he/she acquired earlier during his/her mechanical engineering studies, the subject will develop a sufficient and up-to-date knowledge in the fields of gas and steam turbine plants and jet and rocket propulsion. In addition to the construction and operation sides, the student will learn how to mathematically describe the phenomenon occurring in such systems.

Oktatás célja

The subject, first, further extends the students’ knowledge in thermodynamics and fluid mechanics to the special field of compressible fluid flow (either gas or steam). Based on this new knowledge and that he/she acquired earlier during his/her mechanical engineering studies, the subject will develop a sufficient and up-to-date knowledge in the fields of gas and steam turbine plants and jet and rocket propulsion. In addition to the construction and operation sides, the student will learn how to mathematically describe the phenomenon occurring in such systems.

Tantárgy tartalma

Schedule of theory 1. week Summary of engineering thermodynamics. Properties of working substances (gas and steam). Mass and energy rate balances. 2. week Application of the first law of thermodynamics. Nozzles, turbines and compressors. Entropy balance for control volume. 3. week Flow of compressible fluids I. Static and stagnation properties. Velocity of sound, Mach number. Flow regimes based on the Mach number. 4. week Flow of compressible fluids II. One-dimensional isentropic flow: effect of cross-section area. Effects of back pressure 5. week Theory behind heat engines. Gas turbine power cycles: Working principle. The Joule-Brayton (JB) cycle: schematics, T-s and p-v planes, thermal efficiency. Effects of irreversibilities, deviations from the JB cycle. 6. week Gas turbine power cycle. The optimum efficiency. Improvement of the thermal efficiency: regeneration, reheat, compressor intercooling. 7. week Vapor power cycles. Rankine-Clausius (RC) cycle: schematics, components, and thermal efficiency. RC cycle on the T-s and h-s planes. Effects of operation conditions and irreversibilities. Reheating the steam, the reheat factor. Supercritical RC cycle 8. week Vapor power cycles. Mean temperature of heat addition. Regenerative RC cycle: ideal and opened feedwater heaters. 9. week Vapor power cycles. Regenerative RC cycle: closed feedwater heaters. Multiple feedwater heaters. Cogeneration. Combined gas and vapor power cycles. 10. week Mid-term test. Boilers. Boiler mountings: safety valve, water-level indicator, pressure gauge, fusible plug, blow-off cock, feed check valve, steam stop valve. Boiler accessories: superheater, economizer, air preheater, steam injector, feed pump, steam traps, steam separator 11. week Boiler draught and performance. Natural draught. Height of the chimney, and its efficiency. Condition for maximum discharge. Artificial draught: mechanical and steam jet draught. Performance evaluation of boilers. Energy balance of boilers 12. week Steam turbines. Velocity triangles. Momentum balance: Euler equation for turbomachinery. Condition for axial discharge. Working principle, classification. Impulse steam turbines: velocity triangles, blade, stage, and net efficiencies. Blade friction. Compounding of impulse turbines 13. week Reaction steam turbines. Velocity diagrams. Degree of reaction. Blade efficiency. Condition for maximum efficiency. Comparison between impulse and reaction steam turbines. Losses in steam turbines

Számonkérés és értékelés

Requirements of the subject in the semester Requirements of the signature: (A) Absences no more than allowed, i.e.: - no more than 3 classes is unverified and - total absences of no more than 12 classes. (B) Successful completion of mid-term tests: One mid-term test will be held in prescribed time. In the test the students have to solve problems similar to those solved in the tutorial classes. In total 50 points can be obtained. The major requirement of the signature is to obtain at least 25 points. In case of attendance education the tests will be written in person, while for online education the Moodle system will be applied for this purpose. In the case of a changing form of education during the semester: the rules of the methods of accountability that have already taken place and those that are still to be done are published in Moodle. The midterm tests can be repeated once, on the very last week of the teaching period. In case of repetition the most recent score is considered. Midterm rules and regulations: Students are required to bring their own writing items and clean papers. No borrowing, lending or exchange of any materials is allowed during the tests. Absentees must produce original medical certificates from approved clinics or hospitals. No parents’ letter will be accepted. Student who is absent from the test without valid reason will be given zero score for that test. A student will be given zero score if he/she is caught cheating during the test. No mobile phones or electronic gadgets that can store, transmit, receive data or information are allowed. Students must not talk, whisper, do hand signals or any other form of verbal or non-verbal communication during the test. Such actions will be considered as having the intention to cheat. Students who are late will not be given extra time. Only essential writing materials are allowed on the student’s desk. All bags, books and any unauthorised materials should be left at the front of the classroom. Failure to follow the oral or written instructions may lead to students being penalised. At the first warning, the instructor automatically evaluates the given work at 0%, at a second warning, the instructor refuses to give signature to complete that subject. in the exam period In the exam period students need to pass the exam on one of the exam days scheduled in NEPTUN. Those students who scored less than 25 points (50% of the total score) in the mid-term tests by the end of the teaching period must take a written exam in which he/she has to solve calculation problems from the entire course material. If the written exam is successful (at least 50%), the student can take the final exam, otherwise the result of the exam is fail. The final exam is oral. The students will receive the list of titles by the end of the 12th week of the teaching period. At the beginning of the oral exam the student picks one title from the first half and one from the second half of the list of titles. After picking, the student will have 15 minutes to take notes. Then, he/she will have to explain the content of the titles in words. The examiner has the right to ask questions related not strongly to the topic of the titles. In case of attendance education the exams will be held in person. In case of online education MS Teams will be used for this purpose. The connection link will be included in the ‘Description’ column of the exam in the Neptun system. Grading The subject ends with an exam, the condition for admission to the exam is to obtain a signature. The exam grade is established by aggregating the practical work and the result obtained in the exam. The value of the exam grade depending on the overall performance:           0- 49% – fail (1);           50- 62% – pass (2);           63- 74% – satisfactory (3);           75- 86% – good (4);           87-100% – excellent (5). Corrections, late Any unsuccessful or unwritten test can be corrected once.

Irodalomjegyzék

Recommended literature Author(s) Year Title Publisher Rathore, M.M. 2010 Thermal Engineering Tata McGraw Hill Education Private Limited Moran, M.J., Shapiro, H.N., Boettner, D.D., Bailey, M.B. 2014 Fundamentals of Engineering Thermodynamics Wiley Rajput, Er.R.K. 2017 Thermal Engineering Laxmi Publications Ltd.

Kurzus szakjai