Title Page
Contents
초록 8
Chapter 1. Introduction 10
1.1. Background 10
1.2. Research objectives 12
Chapter 2. Basic Theory 15
2.1. Electric Propulsion System 15
2.1.1. Brief History of Electric Propulsion System 15
2.1.2. Benefits of Electric Propulsion System 17
2.1.3. AC & DC Grid 21
2.1.4. Use of DC Grid 23
2.1.5. Component of DC Grid 23
2.2. Emission 28
2.2.1. GHG / CO₂ 29
2.2.2. NOₓ 32
2.3. Specific Fuel Oil Consumption 34
Chapter 3. Methodology 37
3.1. Overview of methodology 37
3.2. Designing of DC-grid system for the MASTC Laboratory 37
3.3. Experimental setup and equipment 40
3.4. Experiment condition 42
Chapter 4. Experiment results 44
4.1. Effects of the engine load on fuel consumption and emissions at the rated engine speed 44
4.2. Effectiveness of the engine speed reduction strategy 47
4.2.1. Effectiveness of the engine speed reduction strategy on exhaust gas emissions 48
4.2.2. Effectiveness of the engine speed reduction strategy on fuel oil consumption 52
Chapter 5. Conclusions 55
References 57
Nomenclature 61
Table 1. MARPOL Annex VI NOₓ emission limits 34
Table 2. The specifications of the AFE rectifier (AC/DC converter) 39
Table 3. The specifications of the DC/AC inverter 39
Table 4. The specifications of the simulated engine 40
Table 5. Measuring ranges and accuracies of the measuring instrument 42
Table 6. Experiment conditions when changing the engine speed while keeping the engine power 43
Figure 1. A Brief History of IMO/MARPOL about Environmental Matters in 1983 ~ 2011 11
Figure 2. Example of a generator engine fuel consumption graph 13
Figure 3. River tanker Vandal 15
Figure 4. A Brief History of Electric Propulsion 17
Figure 5. Three comparative concepts, how space can be better utilized with electric propulsion and podded propulsion 19
Figure 6. Development and Distribution of Electrical Propulsion Fleet 20
Figure 7. Electric circuit of conventional variable frequency driver 24
Figure 8. Common Structure of Active Front End 25
Figure 9. Form of Inverter Output 27
Figure 10. Annual Greenhouse Gas Index and Radiative Forcing in 1979~2019 30
Figure 11. IMO action to reduce GHG emissions from ships until 2020 31
Figure 12. The future plan to reduce GHG emissions from IMO 32
Figure 13. IMO NOₓ Emission Regulation Chart 33
Figure 14. Coriolis Flowmeter Measuring Principle 36
Figure 15. The schematic diagram of the DC-grid system designed for the MASTC laboratory 38
Figure 16. The schematic minimalistic diagram of the DC distribution system designed for the MASTC laboratory 38
Figure 17. The schematic diagram of the experiment 40
Figure 18. The species concentration analysis when changing the engine load at the rated speed 46
Figure 19. NOₓ emission according to different engine speeds at 50% (a) and 75% (b) engine load 49
Figure 20. CO₂ emission according to different engine speeds at 50% (a) and 75% (b) engine load 49
Figure 21. CO emission according to different engine speeds at 50% (a) and 75% (b) engine load 50
Figure 22. The BSFOC of the engine at 50% (a) and 75% (b) engine load according to engine speeds 54