표제지
요약문
ABSTRACT
목차
Nomenclature 12
제1장 서론 21
1.1. 연구 배경 21
1.2. 연구 동향 25
1.2.1. 태양열 메탄 분해 반응기 25
1.2.2. 메탄 분해용 촉매 30
1.3. 연구 목적 31
제2장 메탄 열분해 실험 33
2.1. 태양열 공급 시스템 33
(1) 40 kWth 태양로[이미지참조] 33
(2) CCD 카메라 34
(3) 직달 일사량계 34
2.2. 사전 연구 38
2.2.1. 쿼츠형 반응기 (직접 가열식) 38
2.2.2. 나선형 튜브 반응기 (간접 가열식) 45
2.2.3. 결론 52
2.3. 실험 장치 구성 53
(1) 가스 실린더 거치대 53
(2) MFC(Mass Flow Controller) 54
(3) 워터 트랩 및 여과 필터 54
(4) 가스 분석기 54
2.4. 반응기 개발 및 실험 59
2.4.1. 원통형 반응기 59
2.4.2. 개선형 반응기 및 캐비티 98
2.4.3. 열 내구성 개선형 반응기 111
2.5. 결론 119
제3장 메탄 열분해 반응기 해석 121
3.1. 해석 목적 121
3.1.1. 메탄 열분해 반응 시스템 123
3.2. 반응기 광학 해석 138
3.2.1. 해석 방법 138
3.2.2. 해석 결과 141
3.3. 반응기 열전달 및 화학 반응 해석 149
3.3.1. 해석 방법 149
3.3.2. 해석 결과 156
3.4. 결론 172
제4장 결론 173
참고문헌 175
Table 2.1. Required heat when methane flow rate is 40 L/min and conversion rate is 80% 63
Table 2.2. Rotary cylindrical reactor (dimensions) 74
Table 2.3. Pellet catalyst properties 74
Table 2.4. Properties of SUS 310S and Inconel 600 78
Table 2.5. Comparison of results by organization 120
Table 3.1. Properties of BP-2000 137
Table 3.2. Thermal amounts at the reactor surface according to the focal distance 148
Table 3.3. Concentrated heat amounts according to location in the cavity 148
Table 3.4. Heat loss according to cavity shape 160
Table 3.5. View factor (from reactor to environment) 160
Table 3.6. Heat for heating and chemical reaction according to cavity model 171
Figure 1.1. Methane equilibrium conversion rate according to temperature and pressure 24
Figure 1.2. Direct and indirect heating reactor 29
Figure 1.3. The research area of this thesis 32
Figure 2.1. 40 kWth solar furnace at KIER[이미지참조] 35
Figure 2.2. Schematic diagram of solar furnace 36
Figure 2.3. CCD camera for observing the focal point 36
Figure 2.4. SOLYS2 sun tracker and CHP1 sensor for DNI measurement 37
Figure 2.5. Direct heating reactor 41
Figure 2.6. Conical catalyst for methane decomposition 42
Figure 2.7. Graphite packing for high temperature 42
Figure 2.8. Water trap for carbon removal 43
Figure 2.9. Direct heating reactor in solar furnace 43
Figure 2.10. Reactor front part 44
Figure 2.11. Spiral tube reactor drawing 47
Figure 2.12. Spiral tube reactor flow path fabrication 47
Figure 2.13. Spiral tube reactor 48
Figure 2.14. Spiral tube reactor inside and temperature sensors 49
Figure 2.15. Spiral tube reactor installed in solar furnace 49
Figure 2.16. Temperatures at different locations and DNI of spiral tube reactor 50
Figure 2.17. Inside the reactor after the experiment 51
Figure 2.18. Schematic diagram of experimental facility 55
Figure 2.19. Gas cylinder holder 55
Figure 2.20. MFC (Mass Flow Controller) 56
Figure 2.21. Water trap 56
Figure 2.22. Cartridge filter 57
Figure 2.23. Gas chromatography for measuring the methane conversion 57
Figure 2.24. Gas analyser for measuring the methane conversion 58
Figure 2.25. Fixed cylindrical reactor (prototype) 61
Figure 2.26. Fixed cylindrical reactor (solar concentrating) 62
Figure 2.27. Fixed cylindrical reactor (after concentrating) 62
Figure 2.28. Rotary cylindrical reactor (prototype) 65
Figure 2.29. Rotary cylindrical reactor (solar concentrating) 65
Figure 2.30. Rotary cylindrical reactor (design drawing) 68
Figure 2.31. Rotary joint connected to the top of the reactor 69
Figure 2.32. Reducer, motor and rotary joint connected to the bottom of the reactor 69
Figure 2.33. Inverter for controlling reactor rotation speed 70
Figure 2.34. Cavity for reactor 70
Figure 2.35. Insulation board and opening in front of the reactor 71
Figure 2.36. Pellet catalyst inside the reactor 71
Figure 2.37. Temperatures and flow rate in the reactor during solar concentrating 72
Figure 2.38. Reactor surface temperature (center temperature 1,000 ℃)-1 73
Figure 2.39. Methane leakage and ignition due to reactor thermal damage 73
Figure 2.40. Material improvement reactor (Inconel 600) 76
Figure 2.41. Damaged material improvement reactor 77
Figure 2.42. Measuring focal size by distance 82
Figure 2.43. NiCrAl metal foam catalyst coated with CB I 83
Figure 2.44. Difference in catalyst activity according to GHSV by temperature 84
Figure 2.45. Long-term performance data of metal foam + CB I catalyst 85
Figure 2.46. Improved reactor insulation 86
Figure 2.47. Experimental procedure-1 89
Figure 2.48. Experimental results-1 90
Figure 2.49. Reactor surface temperature (center temperature 1,000 ℃)-2 91
Figure 2.50. Experimental results-2 93
Figure 2.51. Experimental results-3 95
Figure 2.52. Experimental results-4 97
Figure 2.53. Improved rotary cylindrical reactor (design drawing) 100
Figure 2.54. Upper and lower flanges of the reactor for separating it from the system 101
Figure 2.55. Improved reactor and cavity 102
Figure 2.56. Mosi2 heaters mounted inside the cavity 103
Figure 2.57. Mosi2 heater controller 103
Figure 2.58. The damaged surface of the improved reactor after test 104
Figure 2.59. Experiment with the improved reactor 107
Figure 2.60. Experimental procedure-2 108
Figure 2.61. Experimental results-5 109
Figure 2.62. Reactor surface temperature (center temperature 1,000 ℃)-3 110
Figure 2.63. Reactor with thermal barrier coating 113
Figure 2.64. Machined nozzles on the upper flange 114
Figure 2.65. Flexible heater connected to the reactor inlet side 114
Figure 2.66. Metal catalyst mounted in the reactor with thermal barrier coating applied 117
Figure 2.67. Experimental results-6 118
Figure 3.1. Reactor and cavity development process 122
Figure 3.2. Parabolic reflector and reactor 125
Figure 3.3. Semi-cavity reactor model 129
Figure 3.4. Installed reactor and parabolic reflector in a solar furnace 130
Figure 3.5. Full-cavity reactor model 132
Figure 3.6. 3D modeling of reactor and cavity 134
Figure 3.7. Difference of activation energy by catalyst 136
Figure 3.8. Solar limb darkening models 140
Figure 3.9. Optical calculation with TracePro 143
Figure 3.10. Heat flux distributions depending on the distance from focal point 143
Figure 3.11. Heat flux profiles at the reactor surface depending on the distance from focal point 145
Figure 3.12. Sun rays distribution in semi-cavity (left) and full-cavity (right) 146
Figure 3.13. Heat flux distributions obtained from optic calculation (full-cavity) 146
Figure 3.14. Transformation of 2D optical results to 3D CFD boundary condition 147
Figure 3.15. Reactor and cavity calculation domain for CFD simulation (semi-cavity model) 153
Figure 3.16. Temperature contour and air velocity vector distributions of center vertical cross-section 159
Figure 3.17. Effect of residence time and temperature on the initial methane conversion about BP-2000 164
Figure 3.18. Methane mass fraction contour of center vertical cross section 166
Figure 3.19. Temperature distribution by height in the reactor (semi-cavity) 167
Figure 3.20. Methane conversion rate by height in the reactor (semi-cavity) 168
Figure 3.21. Temperature distribution by height in the reactor (full-cavity) 169
Figure 3.22. Methane conversion by height in the reactor (full-cavity) 170