Refrigeration and Heat Pumps

Code:

M.EM036

Acronym:

EBC

Keywords
Classification	Keyword
OFICIAL	Fluids and Energy

Instance: 2023/2024 - 1S

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

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
M.EM	34	Syllabus	2	-	4,5	39	121,5

Teaching language

English
Obs.: Excecionalmente, se todos os estudantes tiverem o Português como língua nativa, as aulas poderão ser lecionadas em Português.

Objectives

Today there are about 1 billion domestic refrigerators, 240 million air-conditioning units and 300,000,000 cubic meters of refrigerated warehouses around the world. The annual sale of cooling systems was estimated to be about 200 billion USD. Accordingly, the understanding of the curricular contents of this UC is nowadays vital in order to guarantee its sustainability. In this way, the various existing and new refrigerant systems are presented in a sequential way and where, in each of them, the design conditions as well as their energy performance are analysed. In the remaining chapters, in addition to providing the refrigeration equipment sizing bases, the technological evolutions that have been suffering in the direction of their best performance are also presented

Learning outcomes and competences

• Know the classification of refrigeration systems.


• Knowledge, understanding and analytical capacity of refrigeration systems and heat pumps in terms of their characterizing parameters.


• Be able to implement improvements in existing refrigeration systems and propose new systems.


• Distinguish and calculate the performance of refrigeration systems powered electrically, thermally and hybrids.


• Know how to size the main equipment of refrigeration systems.


• At the end of the course it is expected that the student will be able to analyse the performance of refrigeration systems as well as acquire the capacity to analyse this type of systems.

Working method

Presencial

Program

1. The Cold Sector in Society - Cold chain.


2. Electrically actuated refrigerator systems - Cycle of Carnot. Steam compression cycles. Transcritical cycles. Reverse Joule-Brayton cycle. Thermoelectric cycles.


3. Thermally actuated refrigerator systems - Absorption Cycle. Adsorption cycle. Ejector cycle.


4. Hybrid refrigerator system - Mixed cycle of steam compression and absorption.


5. Components of refrigeration systems and dimensioning - Compressors. Expansion systems. Condensers and evaporators.


6. Refrigeration Fluids - Groups of refrigerating fluids and their designation; characteristics of refrigerant fluids; problems of ozone layer depletion and greenhouse effect; new refrigerant fluids.


7. Cooling Loads - Heat power through the border of the cold rooms; calorific power generated inside the cold room and its relation with the type of products to be conserved; thermal bridges; condensation. Heat pump technology.

Mandatory literature

Clito Félix Alves Afonso; Termodinâmica para engenharia. ISBN: 978-972-752-143-2
Clito Afonso; Sistemas Frigorificos e Bombas de Calor : Colectânea de Problemas Resolvidos, Efeitos Gráficos, 2018. ISBN: 978-989-99559-8-1

Complementary Bibliography

Óscar David dos Santos Mota; Exercícios resolvidos de termodinâmica. ISBN: 978-989-752-268-0
Gordon Rogers; Engineering thermodynamics work and heat transfer. ISBN: 0-582-04566-5
W. F. Stoecker; Refrigeration and air conditioning. ISBN: 07-061615-9
American Society of Heating, Refrigerating and Air-Conditioning Engineers; 2018 ASHRAE® handbook Refrigeration, ASHRAE - American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., , 2018
American Society of Heating, Refrigerating and Air-Conditioning Engineers; 2017 ASHRAEc2ae handbook. ISBN: 978-1-5231-1351-4

Teaching methods and learning activities

In theoretical classes the matter is exposed through power point. In theoretical and practical classes thye bstudents must learn a code to solve refrigeration systems. Students must still over the semester to solve at home a set of problems.

Software

EES - Engineering Equation Solver
Aspen Plus

keywords

Physical sciences > Physics > Thermodynamics > Applied thermodynamics
Technological sciences > Technology > Energy technology > Generation of heat

Evaluation Type

Distributed evaluation with final exam

Assessment Components

Designation	Weight (%)
Teste	70,00
Trabalho prático ou de projeto	30,00
Total:	100,00

Amount of time allocated to each course unit

Designation	Time (hours)
Elaboração de relatório/dissertação/tese	40,00
Estudo autónomo	42,50
Frequência das aulas	39,00
Total:	121,50

Eligibility for exams

The evaluation consists of a written examination with all the subjects of the UC (with consultation) and have a weight of 70% of the final grade (20) and in the evaluation resulting from the project developed during the semester with a weight of 30% of the final grade.
The access to the final written examination, which covers all subjects, requires a mark of at least 6.0 values ​​obtained in the written examination and in the evaluation of the project. In the final exam there is only a written examination, with a score of 20 points. Failure to attend the written examination, or the performance of the project, is classified with zero values.
In the appeal examination the evaluation will be identical to the final examination.
The evaluation rules are identical for workers with TE status, or any other status, taking their tests on the same days and hours as those of regular students. Improvement of classification or proof of approval to be taken at the time of appeal, outside the same or other times of examination, the same evaluation rules apply at the time of appeal. All written tests have a duration of 2.0h.

Calculation formula of final grade

70%x( final exam) + 30% (case study report)

Students who undertake the resource test, the final classification will be the higher of those obtained in the two tests.

Examinations or Special Assignments

Not applicable

Special assessment (TE, DA, ...)

As per the rules in force.

Classification improvement

Not applicable