목차

Chapter 1. Introduction 1
1.1 Background of the study 1
1.2 Literature survey 3
1.3 Objectives and scopes 10
Chapter 2. Numerical analysis on the cathode humidification of direct water injection method 12
2.1 Introduction 12
2.2 Numerical model of cathode humidification 13
2.2.1 Selection of atomizer and its model 13
2.2.2 Humidification model of injected water 21
2.2.3 PEM fuel cell model 28
2.3 Simulation results 32
2.3.1 Atomization performace 32
2.3.2 Humidifiaction performance 34
2.4 Summary 38
Chapter 3. Fundamentals of direct water injection system and feasibility test 39
3.1 Introduction 39
3.2 Development of water injection system 40
3.2.1 Application of the atomizer to air-providing part 40
3.2.2 Performance evaluation method 42
3.3 Feasibility test 46
3.3.1 Water atomization performance 46
3.3.2 Experimental setup and test procedure 52
3.3.3 The effects of direct water injection method 58
3.4 Summary 69
Chapter 4. Operating characteristics of PEMFCs with a direct water injection system 70
4.1 Introduction 70
4.2 Humidification performance 70
4.2.1 Experimental apparatus and test procedure 70
4.2.2 Water injection flow rate 77
4.2.3 Water injection temperature 79
4.2.4 Stack operating temperature 81
4.2.5 Stack operating pressure 83
4.2.6 Cathode stoichiometric ratio 83
4.3 Evaporative cooling performance 86
4.3.1 Experimental apparatus and test procedure 86
4.3.2 Water injection flow rate and stack operating temperature 87
4.3.3 Water injection temperature 91
4.3.4 Stack operating pressure 93
4.3.5 Cathode stoichiometric ratio 95
4.4 Development of an operating strategy for PEMFCs with a direct water injection system and verification 99
4.4.1 The effects of intermittent water injection 99
4.4.2 Start-up with a direct water injection system 111
4.5 Summary 113
Chapter 5. Concluding remarks 114
References 117
Abstract (in Korean) 123