2023-2024 / MECA0512-1

Thermodynamics and heat engines : applications in building industry

Duration

26h Th, 26h Pr

Number of credits

 Bachelor of Science (BSc) in Architectural Engineering4 crédits 

Lecturer

Vincent Lemort

Language(s) of instruction

French language

Organisation and examination

Teaching in the second semester

Schedule

Schedule online

Units courses prerequisite and corequisite

Prerequisite or corequisite units are presented within each program

Learning unit contents

The lecture will introduce the definitions of a system (open and closed), of thermodynamic properties (temperature pressure, specific volume, internal energy, etc.), of the state of a system and of processes. The first law of thermodynamics will then be introduced. The different mechanisms of energy transfer will be described (among which transfers by heat or by work). We will learn how to express an energy balance across a closed system or across a cycle.
The characterization of the state of a fluid or a mixture will be covered: use of the thermodynamic diagrams, description of the solid, liquid and gaseous states, use of the ideal gas model, description of the phase changes. The concepts of conservation of mass and energy will be applied to the study of control volumes. The investigated systems will find an application in the field of buildings: thermal storages (heat/cold), heat exchangers (radiators, solar collectors), pumps and compressors, etc. The second law of thermodynamics will be introduced, based on the definitions of reversible and irreversible processes, and applied to the study of thermodynamic cycles. We will define the entropy of a system and the isentropic effectiveness of a process. Finally, the notion of exergy will be addressed. The main thermodynamic cycles will be studied (vapor compression cycles (Rankine and refrigeration), Brayton-Joule, Stirling, Otto, Diesel, etc.) and the thermal machines and systems that describe those cycles will be described. The study of cycles will exploit the first and second laws of thermodynamics. Once again, the thermal machines and systems introduced in this lecture will find an application in the sector of buildings (vapor compression refrigeration and heat pump cycles, tritherm machine (solar air-conditioning and trigeneration), internal combustion engines for small and medium scale combined heat and power). Finally, the lecture will cover the study of psychrometrics: characterization of moist air (humidity ratio, relative humidity, dew point and wet bulb temperatures), use of moist air diagrams, study of air-conditioning processes (among which humidification and dehumidification processes, mixing of moist air streams, working principle of a cooling tower).

Learning outcomes of the learning unit

The goal of this lecture is to give a basic training to non-specialized engineers by stressing practical aspects as well as direct applications to the building sector. At the end of the lecture, the student will be able to assess the performances of a thermal machine or system by exploiting the concepts of energy and entropy balances. When investigating those systems, the point of view of the user will be considered.

Prerequisite knowledge and skills

Basic concepts in general thermodynamics, fluid mechanics, thermal transfers, and combustion. The lecture will recall briefly the basic concepts of applied thermodynamics but will mainly cover practical applications.

Planned learning activities and teaching methods

The lecture will consist in 12 sessions of 4 hours. Each session will comprise a 2 hours lecture followed by a 2 hours session of exercises on computers.
The exercises are given at the beginning of the sessions and are solved by means of EES software (Engineering Equations Solver). The instructor and the student solve together the exercises. The solution is displayed on a screen by means of a projector. At the end of the session, the solutions are sent to the student by email.
The lecture is also illustrated through 1 session of laboratory that gives the opportunity to the students to exploit the concept of energy balance when investigating real systems. The laboratory sessions will be defined as function of the ongoing research projects at the thermodynamic laboratory. They may deal with the study of a compressor, a boiler, a heat pump, a room air-conditioner, etc. Before the date of the exam, the student will have to provide a report describing the test bench, the achieved measurements, their analysis, the simulation model of the thermal machines developed by the student and its experimental validation.

Mode of delivery (face to face, distance learning, hybrid learning)

Face-to-face

Recommended or required readings

The class material consists in a text book that is revised every year and is distributed to the students chapter by chapter before the lectures.

The exam consists in one question of theory (3 points) and two exercises (7 points per exercise). The theoretical question is prepared on a sheet and is defended orally. The two exercises are solved on a computer (by means of EES software) and will be defended orally. The students are not allowed to use the textbook of the class to solve the exercises.
The report about the laboratory session will account for 3 points.
The second session exam is organized in an identical way as during the first session.

Work placement(s)

Organisational remarks and main changes to the course

Contacts

Vincent Lemort Thermodynamics and Energetics Laboratory University of Liège Campus du Sart Tilman, B49 B-4000 Liège, Belgiquewww.labothap.ulg.ac.be Tel: +32 4 366 48 01 Tel Secretariat: +32 4 366 48 00

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