Title Page
Contents
1. Introduction 12
1.1. Research Background 12
1.2. Common SOFC conformations 14
1.2.1. SOFC Theoretical Research 18
1.2.2. SOFC efficiency 21
1.3. Research status on SOFC numerical simulation 23
2. Computational Fluid Dynamics (CFD) Overview 30
2.1. CFD control equations 30
2.2. CFD turbulence models 31
2.3. Standard k-ε Turbulence Model 31
3. SOFC manifold optimization design 33
3.1. SOFC Stack Design 33
3.2. SOFC stack flow analysis 36
3.3. Results and considerations 39
3.4. Conclusion 44
4. SOFC separation plate gas channel height optimization design 45
4.1. SOFC Stack Design 45
4.2. Experimental methods 47
4.3. Calculation results 48
4.4. Conclusion 54
5. Summary of this thesis 55
6. References 57
Abstract 61
국문요약 63
Table 1.1. Parameters of Different Types of Fuel Cells 12
Table 1.2. Advantages and disadvantages of unit cell structures with different support structures 16
Table 3.1. Design parameters of the stack 34
Table 3.2. Boundary conditions for mass flow inlet 38
Table 3.3. Calculated results for anode flow 41
Table 3.4. Calculated results for cathode flow 41
Table 4.1. Design parameters of 1kWe SOFC stack 45
Table 4.2. Boundary conditions for mass flow inlet 48
Table 4.3. Statistics of calculation results for anode flow 51
Table 4.4. Statistics of calculation results for cathode flow 52
Fig. 1.1. Schematic diagram of SOFC 13
Fig. 1.2. Schematic diagram of the plate type SOFC structure 14
Fig. 1.3. Structure diagram of three types of planar SOFCs: cross-flow, co-flow and counter-flow 15
Fig. 1.4. Tubular SOFC 17
Fig. 1.5. Tafel plot 20
Fig. 1.6. Inlet and outlet manifold shapes (a) and velocity vectors for different sizes (b) of inlet manifold designed 25
Fig. 1.7. Velocity distribution of air in different gas channels(m•s⁻¹) : (a) Z-type parallel and (b) triple-parallel serpentine 26
Fig. 1.8. Mole fraction of oxygen in cathode layer(Vcell=0.6V): (a) Z-type parallel and (b) triple-parallel serpentine 26
Fig. 1.9. Temperature contour plot[℃] @iavg=3,000A/m²; Uf=70%; UO=30%; (a) Parallel flow, (b) Countercurrent flow, (c) Perpendicular... 28
Fig. 3.1. Design of 1 kWe SOFC stack (40 cells) 34
Fig. 3.2. Six sizes of internal manifolds: (a) anode manifold 2.5 mm; (b) anode manifold 5.0 mm; (c) anode manifold 10.0 mm; (d) cathode manifold... 36
Fig. 3.3. Static pressure contours of Uf=80% for anode flow and Uo=30% for cathode flow: (a) Anode manifold 2.5 mm; (b) Anode manifold 5.0 mm;... 38
Fig. 3.4. Mass flow rates for anode/cathode manifold size 5.0 mm: (a) Anode Uf = 80%; (b) Cathode Uo=30% 40
Fig. 3.5. Flow uniformity: (a) Anode; (b) Cathode 43
Fig. 4.1. Numerical models for SOFC stacks according to different anode and cathode of gas channel Heights: (a) Han = 0.375 mm; (b) Han = 0.75... 46
Fig. 4.2. Mesh generation for numerical analysis : (a) Han = 0.75 mm; (b) Hca = 0.87 mm 47
Fig. 4.3. Pressure contours of Uf = 80% for anode flow and Uo = 30% for cathode flow: (a) Han = 0.375 mm; (b) Han = 0.75 mm; (c) Han = 1.5... 49
Fig. 4.4. Normalized mass flow rate for each cell : (a) Anode @ Uf = 80%; (b) Cathode @ Uo = 30% 51
Fig. 4.5. Flow uniformity index: (a) Anode; (b) Cathode 53