Supercritical Carbon Dioxide in Microchannel Devices for Advanced Thermal Systems

Brian M. Fronk

School of Mechanical, Industrial and Manufacturing EngineeringOregon State University, Corvallis, OR, USA

March 30th, 2017

Presented at Oklahoma State University

Outline

1. My Background

2. Supercritical CO2 Solar Thermal Receivers

3. Experimental Microchannel sCO2 Heat Transfer

2

My Background

3

Oregon State University

4

…is Oregon’s Land Grant university with the mission to educate the students of the state; it is a public

research university with eleven colleges and the state’s primary research engineering program.

The College of

Engineering, by

the numbers:

10%growth in enrollment

(annual average)graduate students

1,304

196faculty in five

engineering schools

7,120undergraduate students

$55.0Mresearch funding

in 2016

School of Mechanical, Industrial and Manufacturing Engineering (MIME)

5

By The Numbers

54 1,900+ 340+ 2x-3x

Research

Faculty

Undergraduate

Students in

4 Majors

Graduate

Students in

4 Majors

Growth in Total

Enrollment over

the past 10 years

Research Interests

6

System Scale

• Concentrated Solar Thermal

• Waste Heat Recovery/CCHP

• Solar Thermal Heating

• Building Energy Systems (HVAC&R)

• Thermal Management Devices

Phenomena Scale

• Multiphase Heat and Mass Transfer

• Supercritical Heat Transfer

Energy Efficiency

Renewable Conversion

EnergyStorage

Concentrated Solar Power (CSP)

7http://www.desertsun.com/story/tech/science/energy/2015/01/22/abengoa-big-plans-solar-towers-desert/22186683/

Next Gen Solar Thermal

8

• Current central receivers operate

at 30 – 100 W cm-2

• Receiver cost estimated

$100-$200/kWt

• Future receiver improvements:• Smaller and simpler design

• Increase thermal transfer efficiency

• Increase receiver exit temperature

• Decrease cost per kWt

• Leverage sCO2 Brayton Cycles

Conboy T, Wright S, Pasch J, Fleming D, Rochau G, Fuller R. Performance Characteristics of an Operating Supercritical CO2 Brayton Cycle. ASME. J. Eng. Gas Turbines Power. 2012;134(11):111703-111703-12. doi:10.1115/1.4007199

Microchannel Receiver Concept

• Demonstrated 90% thermal efficiency at 2 x 2 cm scale

9L’Estrange T, Truong E, Rymal C, et al. High Flux Microscale Solar Thermal Receiver for Supercritical Carbon Dioxide Cycles. ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels:V001T03A009. doi:10.1115/ICNMM2015-48233.

Research Question

Can micropin devices be scaled to megawatt capacities?

10

Numbering Up Concept

11Zada K. R., Hyder M. B., Drost M. K., Fronk B. M. Numbering-Up of Microscale Devices for Megawatt-Scale Supercritical Carbon Dioxide Concentrating Solar Power Receivers. ASME. J. Sol. Energy Eng. 2016;138(6):061007-061007-9. doi:10.1115/1.4034516

Unit-Cell Level

12

Thermal Model

[9]13

Thermal Model

16

23 sCOQ Q

2 2 2( )sCO sCO s W sCOQ h A T T

Thermal Network Model

18

Module Level

19

Multi-Unit Cell Module

Module Level

20

Flow Distribution Model

21

Module Level Results

22

Fluid Inlet Temperature 550°C

Incident flux 140 W cm-2

System Pressure 250 bar

Ambient Temperature 20°C

Wind Speed 2 m s-1

Module Level Results

23

Fluid Inlet Temperature 550°CFluid Outlet Temperature

720°C

System Pressure 250 barNumber of Unit Cells per

Module6

Mass flow rate Varying

Receiver Model

250 Modules = 250 MW thermal input

24Zada K. R., Hyder M. B., Drost M. K., Fronk B. M. Numbering-Up of Microscale Devices for Megawatt-Scale Supercritical Carbon Dioxide Concentrating Solar Power Receivers. ASME. J. Sol. Energy Eng. 2016;138(6):061007-061007-9. doi:10.1115/1.4034516

Receiver Model Results

25Zada K. R., Hyder M. B., Drost M. K., Fronk B. M. Numbering-Up of Microscale Devices for Megawatt-Scale Supercritical Carbon Dioxide Concentrating Solar Power Receivers. ASME. J. Sol. Energy Eng. 2016;138(6):061007-061007-9. doi:10.1115/1.4034516

Modular Receiver Concept

26

Conclusions

• Pathway to megawatt scale demonstrated

• Modular concept advantageous• Tailored receiver design

• Manufacturability

• Physical test article designs generated• Pin-level CFD (Dr. S. Apte – OSU)

• Manufacturing (Dr. B. Paul – OSU)

• Materials/Solid Mechanics (Dr. R. Maholtra – OSU)

• Reciever Structural Analysis (Dr. D. Borello - OSU)

27

Ongoing Work

28

Supercritical CO2

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Tcritical (ᵒC/ᵒF) 31.0 / 87.9

Pcritical (kPa/PSI) 7377.3 / 1072

Applied Science, 2011, https://www.youtube.com/watch?v=-gCTKteN5Y4

Supercritical CO2 Heat Transfer

30

How to Exploit?

• Supercritical Brayton

• HVAC&R (cooling)

• Thermal Management?

31Fronk B. M., Rattner A. S. High-Flux Thermal Management With Supercritical Fluids. ASME. J. Heat Transfer. 2016;138(12):124501-124501-4. doi:10.1115/1.4034053.

Convective Heat Transfer

32

Thermophysical Property Variation

• Buoyancy Effects

• Bulk Flow Acceleration

• Flow Profile Changes

Heat Transfer

Affected

Convective Heat Transfer

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Stratification of low-density fluid

DH = 10.9 mm

Pidiparti et al., 2015

Pidaparti S, Jarahbashi D, Anderson M, Ranjan D. Unusual Heat Transfer Characteristics of Supercritical Carbon Dioxide. 2015. ASME International Mechanical Engineering Congress and Exposition, Volume 8A: Heat Transfer and Thermal Engineering:V08AT10A040. doi:10.1115/IMECE2015-51225.

Research Objectives

1. Experimentally investigate heat transfer for single-wall applied heat flux in small diameter channels

2. Evaluate applicability of convective heat transfer correlations

3. Create a publically available database

4. Use data to verify DES models (Dr. A. Rattner PSU)

34

Experimental Facility

35

Experimental Facility

36

Test Section Design

37

Test Section

Heat Length (mm) 20

Development Length (-) 40D

Hydraulic Diameter (mm) 0.75

Number of Channels (-) 5

Aspect Ratio (-) 1:1

Measurement Technique

38

Measurement Technique

39

Test Section Fabrication

40

Dh (mm) 0.75

AR (-) 1:1

Type Channel

Dh (mm) 0.75

AR (-) 2:1

Type Channel

Dh (mm) 0.75

AR (-) N/A

Type Staggered Pin

Test Section Fabrication

41

Test Section Fabrication

42

Dh (mm) 0.75

AR (-) 1:1

Type Channel

Dh (mm) 0.75

AR (-) 2:1

Type Channel

Dh (mm) 0.75

AR (-) N/A

Type Staggered Pin

Test Section Fabrication

43

Reduced Pressure (-) 1.03 1.1

Mass Flux (kg m-2 s-1) 500 500 1000

Heat Flux (W cm-2) 20 40

Inlet Temperature (°C) 20 – 100 20 – 100

44

Experimental Matrix

Dh (mm) 0.75

AR (-) 1:1

Type Channel

Heat Transfer Results

45

Heat Transfer Results

46

Heat Transfer Results

47

Tpc ≈ 35.4°CTpc ≈ 32.4°C

Single-Phase Correlations

48

Dittus and Boelter, 1930

Wu and Little, 1984

Adams et al., 1998

Importance of Buoyancy?

50

Conclusions

1. Functioning supercritical facility (up to 18 Mpa & 200°C)

2. High heat transfer coefficients measured• Poor correlation predictive capability (under prediction)

• Geometry and boundary conditions

3. Buoyancy effects potentially play a role in heat transfer

51

Ongoing Work

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1. Investigation of different geometry and orientation

2. 2nd Generation experiment • Lower uncertainty

• Higher heat fluxes

3. Develop new test article, local HTC

Acknowledgments

• TEST Lab Students

• SunShot Collaborators

• Dr. M. K. Drost (OSU)

• Dr. S. Apte (OSU)

• Dr. B. Paul (OSU)

• Dr. H. Wang (OSU)

• Dr. R. Maholtra (OSU)

• Dr. V. Narayanan (UC-Davis)

• Dr. O. Dogan (NETL)

• Dr. A. Rattner

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Questions?

54