표제지
감사의 글
목차
Nomenclature 12
ABSTRACT 15
I. 서론 20
1. 연구 배경 20
2. 선행연구 35
2.1. 다중효용 담수생산 설비에 관한 연구 35
2.2. 열압축기에 대한 연구 36
2.3. 수평 전열관에 대한 연구 37
3. 연구목적 39
II. 다중효용 담수설비의 운전이론 41
1. 기본 이론 41
2. 증발식 담수화설비의 열정산 46
3. 시스템 구성 49
3.1. 열압축기 49
3.2. 진공 증발기 52
3.3. 스팀 보일러 53
3.4. 증기 이젝터 진공장치 53
3.5. 응축기 53
III. CFD를 이용한 열압축기의 성능해석 59
1. 열압축기의 작동원리 및 지배방정식 59
2. 경계조건 및 수치해석 모델 64
2.1. 본 연구대상 열압축기의 유동조건 64
2.2. 격자계 구성 65
2.3. 수치계산을 위한 물성치 71
2.4. 난류해석 - 표준Κ-ε모델 71
2.5. 경계조건 (Boundary condition) 75
2.6. 수렴조건 75
3. 수치해석 결과 및 고찰 76
3.1. 구동증기 압력의 변화에 따른 영향 76
3.2. 흡입증기의 온도 변화에 따른 영향 82
3.3. 구동노즐 직경에 따른 영향 87
IV. 다중효용 담수설비의 성능시험 92
1. 성능시험 범위 및 방법 92
2. 성능시험 결과 및 고찰 94
2.1. 구동증기 압력의 변화에 따른 영향 94
2.2. 흡입증기 온도변화에 따른 영향 102
3. 성능시험결과 및 수치해석 결과의 비교 108
3.1. 구동증기 압력의 변화에 따른 영향 108
3.2. 흡입증기의 온도 변화에 따른 영향 114
V. 증발기의 전열특성 및 실험 118
1. 증발기의 유동특성 118
1.1. 수평전열관의 유동패턴 118
1.2. 수평전열관의 증발 열전달 상관관계식 120
2. 성능시험 범위 및 방법 123
2.1. 실험장치 123
2.2. 액막 유동의 실험 조건 127
3. 액막유동 실험 결과 및 고찰 130
3.1. 액막의 유동 패턴 130
3.2. 열전달 실험결과 137
VI. 결론 146
참고문헌 148
Appendix 155
연구실적 167
Table 1. Characteristics of the desalination technologies 27
Table 2. Composition of seawater 29
Table 3. Performance comparisons between the MSF & MED type desalination plants 30
Table 4. Operating cost analysis of the MSF & MED type desalination plants 31
Table 5. Design condition for 5 effect MED-TVC system 50
Table 6. Design conditions of thermo-compressor 66
Table 7. Comparison of CFD model to experimental results 70
Table 8. Thermal property of water vapor & air 74
Table 9. Calculation result according to motive steam pressure 78
Table 10. Calculation result according to suction pressure 83
Table 11. Calculation result according to jet nozzle diameter 88
Table 12. Experimental results - Pressure distribution at TVC 96
Table 13. Experimental results - Pressure distribution at evaporator 97
Table 14. Experimental results - Temperature distribution at evaporator 98
Table 15. Experimental condition 128
Table 16. Boundary condition of tube bundle 132
Table 18. Experimental results of thin film evaporator at mass flow per unit length : 0.038 kg/ms 139
Table 19. Experimental results of thin film evaporator at mass flow per unit length : 0.050 kg/ms 140
Table 20. Experimental results of thin film evaporator at mass flow per unit length : 0.060 kg/ms 141
Fig. 1. Global installed desalination capacity since 1965. 23
Fig. 2. Global constructed capacity of the desalination plants. 24
Fig. 3. Distribution of the desalination technologies. 25
Fig. 4. Contracted capacity by technology. 26
Fig. 5. Gain output ratio according to evaporator stages. 28
Fig. 6. Basic arrangement of MED type desalination plant 32
Fig. 7. Basic arrangement of MED-TVC type desalination plant 33
Fig. 8. Basic arrangement of MED-MVC type desalination plant 34
Fig. 9. Schematic diagram of 5 effect 5 stage suction. 44
Fig. 10. Schematic diagram of 4 effect 2 stage suction. 45
Fig. 11. Dimension of experimental thermo-compressor. 51
Fig. 12. Layout of circular type evaporator. 55
Fig. 13. Layout of rectangle type evaporator. 56
Fig. 14. Steam jet vacuum ejector. 57
Fig. 15. Layout of condenser. 58
Fig. 16. Pressure and velocity pattern in thermo-compressor. 61
Fig. 17. CFD model for thermo-compressor. 67
Fig. 18. Coarse Grid (12,000 cells). 68
Fig. 19. Fine Grid (24,000 cells). 69
Fig. 20. Flow rate according to motive steam pressure. 79
Fig. 21. Discharge pressure according to motive steam pressure. 80
Fig. 22. Entrainment ratio according to motive steam pressure. 81
Fig. 23. Mass flow according to suction pressure. 84
Fig. 24. Discharge pressure according to suction pressure. 85
Fig. 25. Entrainment ratio according to suction pressure. 86
Fig. 26. Mass flow according to jet nozzle diameter. 89
Fig. 27. Discharge pressure according to jet nozzle diameter. 90
Fig. 28. Entrainment ratio according to jet nozzle diameter. 91
Fig. 29. Temperature distribution of evaporator according to the motive steam pressure. 99
Fig. 30. Pressure distribution of evaporator according to the motive steam pressure. 100
Fig. 31. Total product and G.O.R according to the motive steam pressure. 101
Fig. 32. Temperature distribution of evaporator according to the suction temperature. 104
Fig. 33. Saturation pressure vs temperature. 105
Fig. 34. Pressure distribution of evaporator according to the suction temperature. 106
Fig. 35. Total product and G.O.R according to the suction temperature. 107
Fig. 36. Comparison between CFD and experimental results of motive steam flow according to motive steam pressure. 110
Fig. 37. Comparison between CFD and experimental results of suction flow according to motive steam pressure. 111
Fig. 38. Comparison between CFD and experimental results of discharge pressure according to motive steam pressure. 112
Fig. 39. Comparison between CFD and experimental results of entrainment ratio according to motive steam pressure. 113
Fig. 40. Comparison between CFD and experimental results of suction flow according to suction pressure. 115
Fig. 41. Comparison between CFD and experimental results of discharge pressure according to suction pressure. 116
Fig. 42. Comparison between CFD and experimental results of entrainment ratio according to suction pressure. 117
Fig. 43. Ideal flow pattern between adjacent tubes. 119
Fig. 44. Falling film regions adapted in the models and heat transfer coefficient distribution along the surface perimeter. 122
Fig. 45. Diagram for experimental facility. 124
Fig. 46. Test section of thin film evaporator. 125
Fig. 47. Test section of thin film evaporator. 126
Fig. 48. Flow pattern of tube bundle. 129
Fig. 49. Simulation modeling and mesh condition. 133
Fig. 50. Flow pattern with every time step. 134
Fig. 51. Flow pattern of tube bundle. 135
Fig. 52. Water film thickness with Reynolds Number. 136
Fig. 53. Nusselt number for evaporator according to unit length mass flow rate. 138
Fig. 54. Over-all heat transfer coefficient according to mass flow per unit length on evaporator. 142
Fig. 55. Over-all heat transfer coefficient according to top brine temperature on evaporator. 143
Fig. 56. Condensing heat transfer coefficient according to mass flow per unit length on evaporator. 144
Fig. 57. Boiling heat transfer coefficient according to top brine temperature on evaporator. 145
Fig. 58. Coordinate system for film condensation on a vertical wall 163
Fig. 59. Boundary layer conditions associated with Nusselt's analysis for a vertical wall 163
Fig. 60. Modified Nusselt number for condensation on a vertical plate 164