표제지
요약문
Abstract
목차
기호설명 10
제1장 서론 15
1.1. 연구 배경 15
1.2. 기존의 연구 19
1.2.1. 고온 연소의 점화-소화한계 19
1.2.2. MILD 연소 21
1.3. 연구목적 26
제2장 수치해석 방법 27
2.1. 지배방정식 27
2.2. 수치해석모델 28
2.3. NOX 생성 모델 33
2.4. 화학반응기구 37
제3장 제트 유동장에서 MILD 연소 39
3.1. 경계조건 39
3.2. 화학반응기구의 검토 45
3.2.1. Jet buner in Hot Coflow (JHC) 45
3.2.2. Wall-Confined Jet (WCJ) 49
3.3. 여러 가지 변수에 따른 MILD 연소 특성 65
3.3.1. 화염분포 65
3.3.2. 오염물질의 분포 69
제4장 대용량 연소로에서 MILD 연소 77
4.1. 경계조건 77
4.2. 연소모델 검토 82
4.3. 대용량 연소로에서 MILD 연소 특성 88
4.3.1. 전산해석 타당성 검토 88
4.3.2. 연소로 내부 유동 분포 90
4.3.3. 합성가스 혼합에 따른 분포 94
4.4. 오염물질 배출 특성 98
제5장 결론 103
참고문헌 105
Table 3.1. Velocities (m/s) of the air stream for each given conditions. 42
Table 3.2. Composition of the air stream for each dilution rates. 42
Table 4.1. Inlet boundary conditions for various fuel composition. 81
Fig. 3.1. Schematic of axisymmetric wall-confined jet geometry for methane MILD combustion. 40
Fig. 3.2. Comparison of the numerical results predicted by each chemical mechanism and measurement at 9% O₂ at Z=30mm in Dally's burner(JHC). 46
Fig. 3.3. Comparison of the numerical results predicted by each chemical mechanism and measurement at 9% O₂ at Z=30mm in Dally's burner(JHC) using steady laminar flamelet(SLF) combustion model. 47
Fig. 3.4. 2D temperature distributions with varying chemical mechanisms and varying dilution rates. 50
Fig. 3.5. 1D cross-sectional temperature and heat of reaction distributions at different axial locations. Comparison between the five chemical mechanisms with varying dilution rates. 51
Fig. 3.6. 2D distributions of the CO mole fractions at Ω=0.0 and Ω=0.5 predicted by the five different chemical mechanisms, i.e., 3-STEP, WD4, SKELETAL, DRM-19, and GRI-2.11. 53
Fig. 3.7. 2D distributions of the NO mole fractions at Ω=0.0 and Ω=0.5 predicted by the five different chemical mechanisms, i.e., 3-STEP, WD4, SKELETAL, DRM-19, and GRI-2.11. 53
Fig. 3.8. 1D cross-sectional distributions of the CO mole fractions at different axial locations. Comparison between the five chemical mechanisms with varying dilution rates. 55
Fig. 3.9. 1D cross-sectional distributions of the NO mole fractions at different axial locations. Comparison between the five chemical mechanisms with varying dilution rates. 57
Fig. 3.10. 1D cross-sectional distributions of the CO net reaction rates at different axial locations. Comparison between the five chemical mechanisms under varying dilution rates. 59
Fig. 3.11. 1D cross-sectional distributions of the NO net reaction rates at selected axial locations: x = 0.2 m and x = 0.6 m. Comparison of the predictions of the five chemical mechanisms with varying dilution rates. 60
Fig. 3.12. Emission indices for NO (EINO) and CO (EICO) predicted by five chemical mechanisms with varying dilution rates. 62
Fig. 3.13. 2D temperature distributions with various Φ, TOX, Ω.(이미지참조) 66
Fig. 3.14. Responses of the maximum temperature in inlet air temperature with various Φ, Ω. 67
Fig. 3.15. 1D cross-sectional temperature at different axial locations. Comparison between the three inlet air temperature with varying dilution rates. 68
Fig. 3.16. 2D distributions of the NO mole fraction at Φ=0.5 with various dilution rate (Ω). And the distributions of the NO mole fraction at Ω=0.5 with various equivalence ratio(Φ). 70
Fig. 3.17. 2D distributions of the CO mole fraction at Φ=0.5 with various dilution rate (Ω). And the distributions of the CO mole fraction at Ω=0.5 with various equivalence ratio (Φ). 71
Fig. 3.18. 1D cross-sectional distributions of the CO mole fraction and production rate at different axial locations. Comparison between the three inlet air temperature with varying dilution rates. (Φ=0.5 was fixed.) 73
Fig. 3.19. Emission indices for NO (EINO) and CO (EICO) with varying dilution rates (Ω) and equivalence ratio (Φ). 74
Fig. 4.1. The photograph of the high capacity MILD combuster. 78
Fig. 4.2. 3D grid systems of MILD combuster. 79
Fig. 4.3. Schematic of the high capacity MILD combuster configuration. 80
Fig. 4.4. 2D temperature distributions with SLF and EDC model for various fuel composition and chemical mechanisms. 85
Fig. 4.5. 2D distributions of major species (O₂, H₂O and CO₂) concentration with SLF and EDC model for various chemical mechanisms at NG fuel. 86
Fig. 4.6. 2D distributions of pollutants (CO and NO) concentration with SLF and EDC model for various chemical mechanisms at NG fuel. 87
Fig. 4.7. Comparison of inside temperature predicted by CFD and experimental measurement results. 89
Fig. 4.8. Complex 3D streamline in MILD combuster with 2D distribution of O₂ mole fraction at NG 70% + Syngas 30 % condition. 91
Fig. 4.9. The three case of complex 3D streamline in MILD combuster with 2D distribution of O₂ mole fraction at NG 70 % + Syngas 30 % condition. 92
Fig. 4.10. 3D iso-surface and 2D distribution of temperature and major species concentration at NG 70 % + Syngas 30 % condition. 93
Fig. 4.11. 2D distributions of temperature and major species concentration for various dilution rate of syngas adopted EDC combustion model and GRI-2.11. 95
Fig. 4.12. Responses of inlet air, exhaust and maximum temperature in dilution rate of syngas. 96
Fig. 4.13. Response of the maximum H₂O and CO₂ mole fraction in dilution rate of syngas. 96
Fig. 4.14. 2D distributions of CO and NO concentration for various dilution rate of syngas adopted EDC combustion model and GRI-2.11. 99
Fig. 4.15. Response of the maximum CO and NO mole fraction in dilution rate of syngas. 100
Fig. 4.16. Comparison of NO emission changed 1% O₂ in dilution rate of syngas predicted by CFD and measured experimental results. 100