In the context of global warming and the energy transition, two essential questions arise: how to cool environments without major environmental impact and how to produce heat efficiently without combustion. These questions reveal a reversal of the energy paradigm that has prevailed since the Industrial Revolution, when the challenge was to produce work from heat.
Reverse cycle thermal machines (refrigeration systems, heat pumps and thermofridges), operating in reverse of the thermomechanical conversion motor cycle, have a major role to play in answering these questions, which are at the heart of the energy challenges that humanity will have to face in the coming decades.
This book first presents a state of the art on these systems, whose operating principle is sometimes old, but whose performance analysis and optimization have sometimes been neglected. Emerging technologies, which will certainly find their place in the future energy panorama, are also discussed.
Foreword ix Michel FEIDT Preface xi Jocelyn BONJOUR Chapter 1 Heating and Cooling by Reverse Cycle Engines: State of the Art 1 Philippe HABERSCHILL and Rémi REVELLIN 1.1 Vapor compression refrigerators and heat pumps 2 1.1.1. Operation principle of closed-circuit refrigeration installation: definitions 2 1.1.2 Actual cycle with superheating and subcooling 5 1.1.3 Special cycles 6 1.1.4 Heat output settings 20 1.2 Systems driven by thermal energy 21 1.2.1 Principle of thermodynamic operation 21 1.2.2 Absorption chillers 22 1.2.3 Ejection machines 38 1.3 References 44 Chapter 2 Entropy and Exergy Analyses Applied to Reverse Cycles 45 Jocelyn BONJOUR and Rémi REVELLIN 2.1 Definition of the study system and objectives 45 2.2 Energy analysis 48 2.2.1 Steady-state system-wide analyses 49 2.2.2 A system-wide analysis: power or energy? 51 2.2.3 Component-scale energy analysis 52 2.3 Entropy analysis 62 2.3.1 Second law of thermodynamics: an entropic power balance 63 2.3.2 Reversible upper limit: Carnot engines 63 2.3.3 Component-scale entropy analysis 72 2.3.4 Phenomenon-scale entropy analysis: two-phase flows with heat transfer and phase change 78 2.4 Exergy analysis 82 2.4.1 From the concept of exergy to proposed definitions 82 2.4.2 Mathematical definitions of exergy 83 2.4.3 Exergy analysis of reverse cycle engines 85 2.5 Case study for exergy analysis 88 2.5.1 Refrigerator with cooled compression and recovery of heat rejected 88 2.5.2 Heat pump running on CO 2 with or without an ejector 90 2.6 References 92 Chapter 3 Thermodynamics and Optimization of Reverse Cycle Engines 93 Michel FEIDT 3.1 Reverse cycle engines according to equilibrium thermodynamics: reminders of the concepts 93 3.2 Receiving engines in the presence of internal irreversibilities 95 3.3 The Carnot refrigerator according to finite-time thermodynamics 96 3.4 The reverse cycle Carnot engine model according to finite physical dimensions thermodynamics (FPDT) 98 3.4.1 Model of a Carnot engine with thermal conductances 98 3.4.2 Immediate extensions of the model with thermal conductances 102 3.5. Generalization of the reverse cycle Carnot engine model according to FPDT 104 3.6 Latest advances in a reverse cycle Carnot engine model 106 3.6.1 Energy model 106 3.6.2. Minimizing the energy expenditure of the Carnot refrigerator (power) 107 3.6.3 The modified Chambadal refrigerator 108 3.6.4 The modified Curzon–Ahlborn refrigerator 110 3.7 Extension of finite physical dimensions thermodynamics to two complex systems 112 3.7.1 Complex two-reservoir systems 112 3.7.2. Some comments on reverse cycle engines with three and four reservoirs 116 3.8 Some conclusions and perspectives 119 3.9 References 119 Chapter 4 Scientific and Technological Challenges of Thermal Compression Refrigerating Systems 121 Florine GIRAUD, Romuald RULLIÈRE and Jocelyn BONJOUR 4.1 Introduction 121 4.2 Kinetics and dynamics – heat and mass transfers in thermal compression engines 122 4.2.1 Absorption theory and design elements of absorbers 123 4.2.2 Adsorption theory and dimensioning elements of adsorbers and reverse cycle adsorption engines 130 4.2.3 Issues associated with transfer kinetics and resistance 135 4.3 Technological challenges in component design 138 4.3.1 Fluid pair 138 4.3.2 Absorber 139 4.3.3 Adsorber 143 4.3.4 Evaporator 151 4.3.5 Coupling of components: the evapo-absorber 156 4.4 Risks associated with liquid–solid phase transition phenomena 160 4.4.1 Crystallization 160 4.4.2 Freezing 162 4.5 Conclusion 163 4.6 References 164 Chapter 5 Magnetocaloric Refrigeration: Principle and Applications 171 Monica SIROUX 5.1 Introduction 171 5.2 Magnetic refrigeration 172 5.2.1 Overview 172 5.2.2 The magnetocaloric effect 174 5.2.3 Magneto-thermodynamic cycles 176 5.2.4 Magnetocaloric materials 182 5.3 Numerical models 186 5.3.1 Numerical models of magnetocaloric regenerators 186 5.3.2 Recent numerical models 189 5.4 Applications 194 5.4.1 Prototypes 194 5.4.2 Future applications 201 5.5 Conclusion 204 5.6 References 204 Chapter 6 Thermoelectric Systems as an Alternative to Reverse Cycle Engines 209 Julien RAMOUSSE and Stéphane PAILHЀS 6.1 Thermoelectricity fundamentals 211 6.1.1 Transport of charge and heat 213 6.1.2 Thermoelectric effects 220 6.1.3 Main lines of research 229 6.2 Implementation and performance analysis 236 6.2.1 Implementation of thermoelectric modules 237 6.2.2 Performance analysis of thermoelectric modules 238 6.2.3 Intrinsic performance of thermoelectric systems 240 6.2.4 Optimal module design 244 6.2.5 Overall performance of thermoelectric systems 245 6.2.6 Thermodynamic analysis of irreversibilities 247 6.2.7 Integration and management 250 6.3 Applications 251 6.3.1 Cooling of electronic and optical components 251 6.3.2 Domestic refrigerator 252 6.3.3 Building applications: air conditioning, room cooling 253 6.3.4 Automotive cooling 253 6.3.5 Autonomous solar cooling 253 6.4 References 254 List of Authors 263 Index 265
Jocelyn Bonjour is Professor in thermodynamics and its application to energy conversion systems. He is a member of the International Institute of Refrigeration and conducts research aimed at improving the efficiency of refrigeration machines and heat pumps.
