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CODE 72354
ACADEMIC YEAR 2024/2025
CREDITS
SCIENTIFIC DISCIPLINARY SECTOR ING-IND/10
LANGUAGE Italian
TEACHING LOCATION
  • GENOVA
SEMESTER 1° Semester
TEACHING MATERIALS AULAWEB

OVERVIEW

The course applies the knowledge that students have already acquired in the lectures of Technical Physiscs and Applied Thermodynamics to develop models and discussions on the technology of cooling systems, with particular reference to vapor compression systems (which are involved in most civil and industrial applications) and absorption systems.

The technological enhancement of refrigeration systems and the various configurations aimed at improving performance and reliability in terms of duration and ease of control are described and analyzed in the light of the most recent thermodynamic, energy and exergetic analysis techniques, also with reference to the relative environmental impact of each plant.

The course is completed by practical project exercises to apply all the acquired concepts  in the design of specific systems, for given refrigeration applications and operating requirements.

 

AIMS AND CONTENT

LEARNING OUTCOMES

The students acquire computational skills for the quantitative evaluation of processes based on vapor compression and absorption reverse cycle. They study the related thermodynamic sizing and optimization criteria and develop the design of the steam compression plants in detail. They learn to evaluate the performance of a refrigeration machine by means of laboratory measurements and theoretical calculation models.

AIMS AND LEARNING OUTCOMES

At the end of the course the student will have the ability to autonomously develop technical, energy and environmental assessments related to reverse cycle ( heat pump and refrigeration systems), as well as the thermodynamic analysis of absorption systems (with particular reference to systems based on water -lithium bromide pair).
In particular, he will be able and will know:
- the use of fluid properties calculation software: REFPROP (NIST), EES.
- learn how to use new specific or generic softwares
- Calculation of the performance of a basic vapor compression refrigeration cycle 
- Exergetic analysis of simple reverse cycles. Exergetic efficiency of reverse cycles, refrigerants and heat pumps.
- Components characteristic definitions for vapor compression machines 
- Technologies for increasing energy efficiency 
- Sizing of the main components (evaporators, condensers, compressors, expansion valves, capillary tubes and thermostatic valves) 
- present the results of their evaluations in a concise but exhaustive technical report.

PREREQUISITES

Advanced knowledge of engineering thermodynamics and ability to learn the use of generic or specific software (calculation tools)

TEACHING METHODS

Each lesson is consist of a frontal lesson of one or more hours in which the calculation methodologies and technologies used in the various refrigeration processes are described.

Specific calculation exercises are carried out in the classroom on specific problems of interest in the field of refrigeration and electric heating (heat pump).

Students are also charged of a design theme to be developed in groups outside of class hours, with the preparation of a short paper (design report) to be delivered before the exam and to be discussed during the oral examinaton.

Students who have valid certification of physical or learning disabilities on file with the University and who wish to discuss possible accommodations or other circumstances regarding lectures, coursework and exams, should speak both with the instructor and with Professor Federico Scarpa (federico.scarpa@unige.it), the Polytechnic School's disability liaison.

 

SYLLABUS/CONTENT

Inverse refrigeration and heat pump cycles. Their performance (COP, EER, efficiency of the second principle of thermodynamics, etc.).

Refrigeration systems: vapor compression, absorption, gas. The basic vapor compression refrigeration cycle (CFCV) and its four+1 components (compressor, condenser, expansion valve, evaporator + refrigerant fluid)

Fundamental calculations of a CFCV. Energy and exergy analysis: the sources of irreversibility and the shape of the cycle in the pv, Ts, ph plans.

Influence of the thermophysical properties of the refrigerant fluid on cycle performance.

Notes on environmental impact: OPD (Ozone Depletion Potential), GWP (Global Warming Impact) and TEWI (Total Equivalent Warming Impact)

Evolution of basic CFCVs for the purpose of reducing the environmental impact (in terms of COP). Double compression cycles with intermediate refrigeration Double expansion cycles (double lamination) with auxiliary compressor Cycles in cascade and analysis of the COP according to the number of cycles and the real performance of the compressor. Fractional lamination cycles. 

Introduction to carbon dioxide cycles

Components of vapor compression refrigeration systems: compressors, valves, thermostatic valves, evaporators, condensers, recovery units and regenerators. Motor condensing units. Sizing methods and choice of components from the catalogue.

Introduction to absorption plants: principles, advantages and operational limits compared to vapor compression plants. Water-lithium bromide plants and ammonia-water plants.

Fundamental components (absorber, generator, pump)

Energy balances for the fluids of an absorption plant. The enthalpy/composition diagram for the water-lithium bromide system

Calculation of the performance of a lithium bromide plant under assigned operating conditions.

RECOMMENDED READING/BIBLIOGRAPHY

The notes taken during the lessons and the material provided and available on AULAWEB (notes of the theoretical part and tutorial of several specific software) are sufficient for the preparation of the exam.

TEACHERS AND EXAM BOARD

Exam Board

JOHAN AUGUSTO BOCANEGRA CIFUENTES (President)

GUGLIELMO LOMONACO

CORRADO SCHENONE (President Substitute)

LUCA ANTONIO TAGLIAFICO (President Substitute)

ANNALISA MARCHITTO (Substitute)

LESSONS

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The exam consists of an oral test, with a discussion of a design work prepared by the student.

Students with SLD, disability or other regularly certified special educational needs are advised to contact the instructor at the beginning of the course to agree on teaching and examination methods that, in compliance with the course objectives, take into account the individual learning requirements.

 

ASSESSMENT METHODS

Discussion of the project activities carried out in the classroom and of specific topics chosen by the teacher

Exam schedule

Data appello Orario Luogo Degree type Note
28/01/2025 11:00 GENOVA Orale
10/06/2025 11:00 GENOVA Orale
17/07/2025 11:00 GENOVA Orale
03/09/2025 11:00 GENOVA Orale

Agenda 2030 - Sustainable Development Goals

Agenda 2030 - Sustainable Development Goals
Affordable and clean energy
Affordable and clean energy
Responbile consumption and production
Responbile consumption and production