Investigation of flow distribution in multiple microchannels

Reporter: Zhang WeihuaSupervisor: Professor Xin Feng

I

• Preliminary ideas

II

• Simulate or not?

III

•Experiment methods

IV

•Further plan

Contents

I Preliminary ideas

1. Explore the specified diameter obtained based on simulation and experiment results, when acceptable distribute performance

2. Search for possible regular pattern from single channel to multiple channels via probabilistic model

3. Propose advisable dividing line between microchannel and macrochannel

II Simulate or not?

CFD simulation was laid aside due to unsatisfying grid and low performance PC

Necessity of CFD simulation: asymmetry structure, radial nonuniformity

Shantanu Roy. Experimental investigation of gas–liquid distribution in monolith reactors. Chemical Engineering Science 62 (2007) 7463 – 7470.

III Experiment methods

CTMRI Liquid collecting methodMicro-conductivity probe……

III Experiment methods

W. Cai et al. Experimental Investigation of Gas Holdup and Slug Lengths in an Upflow Monolith Reactor. Chem. Eng. Technol. 2011, 34, No. 6, 955–962.

III Experiment methods

W. Cai et al. Experimental Investigation of Gas Holdup and Slug Lengths in an Upflow Monolith Reactor. Chem. Eng. Technol. 2011, 34, No. 6, 955–962.

III Experiment methods

W. Cai et al. Experimental Investigation of Gas Holdup and Slug Lengths in an Upflow Monolith Reactor. Chem. Eng. Technol. 2011, 34, No. 6, 955–962.

III Experiment methods

W. Cai et al. Experimental Investigation of Gas Holdup and Slug Lengths in an Upflow Monolith Reactor. Chem. Eng. Technol. 2011, 34, No. 6, 955–962.

Some places to be improved:1 Narrow adaptable intervals2 Dependency on light source3 Deviation existing in estimation of film thickness and measuring of bubble diameter4 Randomly picked 5 channels to represent overall performance

III Experiment methods

1 Choice of multiple microchannel

Capillary or honeycomb ceramic

2 Channel shape Round or square3 Channel arrangement Radial pattern or…4 Accessories Plexiglass cylinder, pipe5 Measurement CT, MRI or Cai’s method

Questions list

III Experiment methods

Parameters preferred:Monolith element diameter: 10mmMonolith element length: 50 mmChannel diameter: 0.1-1mmSuperficial velocity: ug 0.08m/s, ul 0.1m/s Sample time: 100 periodsSample channel number: tmtb

III Experiment methods

｛hGas holdup or

Maldistribution

Critical dimensions

Entrance effect

Gas/liquid superficial

velocity

IV Further plan

1. Jul to Aug: Experiment2. Sep to Oct: CFD simulation3. Simulate multichannel cases by Monte

Carlo or Chaotic Theories?4. Proposal of dividing line

Thank you ！Da

nke