1. Heat transfer gradient through the reactor
Yan & Vasudha
Good evening, every one! Our topic today is heat transfer gradient through the reactor.
EGEE 520 project presentation
Dec

2. Introduction 2 Steel Al2O3 Air Glass reactor Fuel 11 9 7 5 3 1 12 10 86 4 2

3. Governing equations 3 εSB: Stefan-Boltzman constant (Wm-2K-4)
k: thermal conductivity (Wm-1K-1)
A: cross-sectional area (m2)
dT/dn: temperature gradient (Km-1)
Conduction:
Convection:
h: heat transfer coefficient (Wm-2K-1)
Tsolid: temperature at the surface of the solid body (K)
Tfluid: ambient or remote temperature of the fluid (K)
Radiation:
εSB: Stefan-Boltzman constant (Wm-2K-4)
σ: emissivity of the surface
Tsolid: temperature at the boundary of the solid body (K)
T∞: ambient temperature (K)
Partial differential equation for heat conduction:

4. 4
Formulation
Initial assumptions: Steady-state process; Axial symmetry (2D); Modes: Convection and Conduction & Incompressible Navier-Stokers
Subdomain and Boundary settings in FEMlab
1. Steady-state process, 2. Ignore contact thermal resistance between each boundary, 3. Thermal conductivity for each material is constant in every direction, 4. The radiation from steel to ambient can be neglected.

5. 5
Solution
Temperature distribution with flow rate 0.01mL/s

6. Validation 6 q = 7.895 W/m3 q = 9.7596 W/m3
Heat gained by fluid when it passes through the reactor:
q = W/m3
Heat transfer through radial conduction in cylindrical wall:
q = W/m3

7. 7
Parametric Study
Temperature distribution with flow rate 0.001mL/s

8. 8
Parametric Study
Temperature distribution with flow rate 0.1mL/s

9. 9
Conclusion
When the flow rate of fuel is high, temperature distribution is roughly symmetric with z = 0. The temperature of fuel is almost constant (293 K) except in two bottoms.
When the flow rate of fuel is decreased, the temperature of fuel increases.
Temperature distributions within Al2O3 and steel almost maintain the same no matter what the flow rate is. However, the temperature distribution within air changes with changing flow rate.
FEMlab is a useful tool for simulation of heat transfer process, and the results of our modeling are reasonable.

10. Questions?