1. Condensation in mini- and microchannels
Hussein Dhanani
Sebastian Schmidt
Christian Metzger
Assistent: Marcel Christians-Lupi
I present to you Stephano Nebuloni, and I’m Anthony Servonet, and we’ll speak about the “microchannel flow boiling correlations and 3-zones model”. On this project, we also compared these model to recent published results.
XX December 2007
Heat and Mass Transfer Laboratory

2. Heat and Mass Transfer Laboratory
Structure
Introduction to condensation in microchannels
Pressure drop
Prediction models
Friedel (1979;1980)
Chen (2001)
Wilson (2003)
Cavallini (2001;2002)
Garimella (2005)
Comparison with experimental data
Conclusion
Heat and Mass Transfer Laboratory

3. Heat and Mass Transfer Laboratory
Structure
Heat transfer
Prediction models
Shah (1979)
Dobson & Chato (1998)
Cavallini (2002)
Bandhauer (2005)
Comparison with experimental data
Conclusions
Questions
Heat and Mass Transfer Laboratory

4. Heat and Mass Transfer Laboratory
Pressure drop
Common parameters used by several correlations
Liquid Reynolds number
Vapor Reynolds number
Liquid-only Reynolds number
Vapor-only Reynolds number
Heat and Mass Transfer Laboratory

5. Heat and Mass Transfer Laboratory
Pressure drop
Common parameters used by several correlations
Single-phase friction factor (smooth tube)
Single-phase pressure gradients
Heat and Mass Transfer Laboratory

6. Pressure drop prediction models
Friedel (1979;1980)
Considered Parameters
Liquid only single-phase pressure gradient
Liquid only and vapor only friction factor
Fluid and geometric properties
Heat and Mass Transfer Laboratory

7. Pressure drop prediction models
Friedel (1979;1980)
Heat and Mass Transfer Laboratory

8. Pressure drop prediction models
Chen (2001)
Modification of the Friedel correlation by adding two-phase multiplier
Considered Parameters
Two-phase pressure gradient by Friedl
We, Bo, Re_v, Re_lo
Heat and Mass Transfer Laboratory

9. Pressure drop prediction models
Chen (2001)
Heat and Mass Transfer Laboratory

10. Pressure drop prediction models
Cavallini (2002)
Modification of the Friedel correlaction by changing several parameter definitions
Considered Parameters
Liquid only single-phase pressure gradient
Liquid only and vapor only friction factor
Fluid and geometric properties
Heat and Mass Transfer Laboratory

11. Pressure drop prediction models
Cavallini (2002)
Friedel
Heat and Mass Transfer Laboratory

12. Pressure drop prediction models
Cavallini (2002)
Heat and Mass Transfer Laboratory

13. Heat transfer prediction models
Cavallini* (2002)
Considered Parameters
Pressure drop
Dimensionless film thickness
Dimensionless temperature
Re, Pr
Fluid and geometric properties
* Applicable for annular regime only
Heat and Mass Transfer Laboratory

14. Heat transfer prediction models
Calculation of the shear stress
Dimensionless film thickness
Heat and Mass Transfer Laboratory

15. Heat transfer prediction models
Dimensionless temperature
Heat transfer coefficient
Heat and Mass Transfer Laboratory