Thermodynamics II

Code:

L.EM013

Acronym:

T II

Keywords
Classification	Keyword
OFICIAL	Fluids and Energy

Instance: 2024/2025 - 1S

Active?	Yes
Responsible unit:	Fluids and Energy Section
Course/CS Responsible:	Bachelor in Mechanical Engineering

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
L.EM	281	Syllabus	2	-	6	52	162

Teaching language

Portuguese

Objectives

ENG

Know how to analyse any thermal engine system in light of the First and Second Law of Thermodynamics. Being able to propose improvements in existing thermal engine systems in terms of their characterizing parameters. Know how to analyse any refrigeration machine and heat pump in light of the First and Second Law of Thermodynamics as well as propose solutions for a better performance. Be able to analyse non-reactive and reactive gaseous mixtures with emphasis on air conditioning and combustion processes. At the end of the course, the student is expected to be able to analyze the performance of thermal energy conversion systems.

Learning outcomes and competences

Thermodynamics is among the great scientific and technical areas, a mother area par excellence since it supports the problem of energy conversion vs. heat. work or thermal energy-mechanical energy and constitutes the backbone of the living sciences. In this context, in the programmatic contents of this UC, chapter by chapter, the basic principles are valued and the conceptualization and the strategy of the use of thermodynamics in the problematic of the energetic conversion of heat vs. work are structured. To do so, most of these existing systems are analysed, making a comparison between all, advantages and disadvantages are discussed. Being that in our society the refrigeration sector is vital, the study of refrigeration systems and heat pumps is carried out in detail. In the two final chapters the air conditioning and the combustion process, essential for the analysis of the thermal machines, are analysed in detail.

Working method

Presencial

Pre-requirements (prior knowledge) and co-requirements (common knowledge)

Thermodynamics I 

Program

FUNDAMENTAL CONCEPTS FOR THE ENERGY CONVERTERTION SYSTEMS ANALYSIS. Efficiency, work ratio and specific consumption of steam/gas systems. THERMODYNAMIC ANALYSIS OF THEFRMAL ENGINE CYCLES Carnot, Rankine, Joule-Brayton and Reciprocating engines cycles. Analysis of the variables. THERMODYNAMIC ANALYSIS OF REFRIGERATING SYSTEMS AND HEAT PUMPS. Analysis of the variation of the COP of these systems as a function of possible changes that can be implement in the ideal cycles. Refrigerant fluids, their classification and impact on the environment. Analysis of variables. GAS MIXTURES Mass, molar and volume fraction of mixtures and their relationship. Dalton’s, Gibb Daltons’ and Amagat’s law. Thermodynamic properties of gaseous mixtures. Second Law analysis of mixture processes. PSICHROMETRY Introduction to the theory of psychrometry. Humid air. Quantification of water vapor content in humid air. Psychrometric charts. Thermodynamic properties of moist air. Analysis of thermal processes involving humid air and respective energy balances. REATIVE MIXTURES Combustion. Stoichiometric combustion and with excess air; flue analysis; enthalpy of formation; adiabatic flame temperature. First and Second Law of Thermodynamics applied to reactive mixtures. Combustion efficiency.

Mandatory literature

P. M. Coelho; Tabelas de termodinâmica. ISBN: 978-972-752-092-3

Complementary Bibliography

Yunus A. Çengel, Michael A. Boles; Thermodynamics. ISBN: 0-07-112177-3
John R. Howell, Richard O. Buckius; Fundamentals of engineering thermodynamics
Clito Afonso; Termodinâmica para engenharia. ISBN: 978-972-752-143-2
Óscar Mota; Exercícios Resolvidos de Termodinâmica Aplicada, Editorial FEUP, 2017. ISBN: s/n

Teaching methods and learning activities

Theoretical lessons - Classroom teaching
Topics exposed with power point with resolution of pratical problems;

Theoretical-Pratical lessons - Classroom teaching

Resolution of problems extracted from a book of problems

Weekly lessons - 4,0 h TP

Laboratory – 4,0h/semester

Total of hours – 75h

Study for examinations – 62h

Students contact (timetable to be defined by each professor).

Evaluation Type

Distributed evaluation with final exam

Assessment Components

Designation	Weight (%)
Exame	75,00
Teste	15,00
Trabalho laboratorial	10,00
Total:	100,00

Amount of time allocated to each course unit

Designation	Time (hours)
Estudo autónomo	95,00
Frequência das aulas	60,00
Trabalho laboratorial	4,00
Total:	159,00

Eligibility for exams

A student is granted attendance to the curricular unit if, having been regularly enrolled, he/she attends at least 75% of the theoretical-practical classes scheduled.

Calculation formula of final grade

The distributed assessment of this curricular unit is performed by:

1) a theoretical mini-test on the Moodle platform covering the first half of the matter, without consultation, to be completed during the semester, with a 15% weight in the final grade.

2) two laboratorial works to be done during the semester, with a 10% weight in the final grade.

During the exam time, the evaluation is comprised of a mini-test on the Moodle platform covering the second half of the matter without consultation, with a 15% weight in the exam grade, and a written exam that consists of all the matter, with a 60% weight.

Failure to attend the theoretical tests, written exams, or laboratory works results in a zero mark.

For other exams, the evaluation will consist of a test in the Moodle platform, covering all the matter without consultation, with a weight of 30%, and a written exam, covering all the matter with a weight of 60%. The laboratory works have a 10% grade and must be completed throughout the semester.

The Moodle tests last 15 minutes, while the written exam takes 105 minutes.

Students with special educational needs are allowed an additional 25% of the proof time.

Special assessment (TE, DA, ...)

The special exam season follows the same assessment rules for the appeal season, i.e., a Moodle test of 30% weight in the final grade and a written exam of 60% weight in the final grade. Evaluation of the lab component should have been obtained beforehand, under penalty of a 10% loss in the final grade.

Classification improvement

Grade improvement follows the same assessment rules for the appeal season, i.e., a Moodle test of 30% weight in the final grade and a written exam of 60% weight in the final grade. Evaluation of the lab component should have been obtained beforehand, under penalty of a 10% loss in the final grade.

Observations

For all examinations, the students can only take with them the thermodynamic tables and a form of four pages A4 written with information that the students think is necessary.