Post on 06-Apr-2022
High Intensity Thermal Exchange through Materials and Manufacturing Processes (HITEMMP)
Annual Program Review Meeting
October 21 & 22 – WebEx
Ultra-High Temperature Ceramic Additively Manufactured Compact Heat Exchangers
(UHT-CAMANCHE)
David W. Lipke, Missouri University of Science and Technology
Project Vision
Extreme Environments. Extreme Materials. Extreme Performance.
Brief Project OverviewFed. funding: $1.8M
Length 36 mo.
DavenportMa
Held
Jape
Leu Lipke
Hilmas
Watts
Fahrenholtz
Park
Team member Location Primary role(s) in project
Missouri S&T Rolla, MO Materials, manufacturing
NREL Golden, CO HX modeling, T2M
Echogen Akron, OH sCO2 design/test consulting
Team Profile
‣ 60+ years professional experience in ceramic engineering
‣ 30+ years professional experience with supercritical CO2 technologies and power cycle development
Project Inception
‣ Convergence of materials (UHTCs), manufacturing technologies (additive manufacturing, ceramic welding), and application (supercritical CO2 power cycles)
Heat Exchanger Design – Key Conceptual Features
2
‣ Counterflow microchannel type
‣ 44x44 array of 0.5mm channels at 2.0mm center-to-center distance
‣ Additively manufactured HX
‣ Graded ceramic-to-metal headers
‣ Pressurized shell
Heat Exchanger Design Details – Performance Metrics
3
Units Hot Side Cold Side
Fluid CO2 CO2
Mass flow rate kg s-1 0.1 0.1
Inlet temperature °C 1100 300
Outlet temperature °C 699 700
Inlet pressure MPa 8 25
Outlet pressure MPa 7.79 24.96
Pressure drop MPa (%) 0.01 (0.03) 0.04 (0.51)
Number of channels 1000 1000
Heat transfer area m2 0.08 0.08
Channel diameter μm 500 500
Surface roughness μm 50 50
Average Pr 0.71 0.79
Average Re 5580 6960
Average Nu 20.4 25.2
Units Values
UA kW °C-1 0.129
LMTD °C 399.1
Effectiveness % 50.2
Q kW 51.5
HX Metrics
core
only
with
headers
Compactness m2 m-3 349 131
Power
density
(volume) MW m-3 153 83
(mass) kW kg-1 25 13
Length cm 5.2 10.8
Width cm 6.7 4.5
Volume cm3 338 622
Mass kg 2.0 4.0
Heat Exchanger Performance Analysis
4
Computational domain of a reduced cell of the heat
exchanger selected for analysis
CFD FEA Initial and refined mesh
‣ Verified mesh convergence and validated CFD/FEA multi-physics heat transfer model
Plane 1
Plane 2
Plane 3
Plane 4
Plane 1 Plane 2
Plane 3 Plane 4
°C
Heat Exchanger Performance Analysis
5
‣ Predicted HX thermal performance (reduced cell model)
‣ Solid thermal conductivity is high (> 50 W m-1 K-1)
‣ Heat transfer is convection limited
‣ Negligible transverse temperature differences
Heat Exchanger Performance Analysis‣ Coupled thermal-mechanical analysis:
6
‣ von Mises stress with hydrostatic compression:
‣ Future modeling work:
– Manufacturing defects
– Manifold optimization for thermal stress and flow maldistribution
Material Selection: ZrB2 + 30% SiC
7
‣ Ultra-high temperature ceramic (Tm.p. > 3000°C)
‣ Various additives improve sintering, oxidation, creep, and toughness
‣ TRL 4-6 depending on application
Neuman EW, Hilmas GE, Fahrenholtz WG.
Mechanical behavior of zirconium diboride-
silicon carbide-boron carbide ceramics up to
2200°C. J. Euro. Ceram. Soc. 2015;35(2):463-
476.
Zimmermann JW, Hilmas GE, Fahrenholtz
WG, Dinwiddie RB, Porter WD, Wang H.
Thermophysical Properties of ZrB2 and ZrB2-
SiC Ceramics. J. Am. Ceram. Soc.
2008;91(5):1405-1411.
Material Compatibility Screening Study
8
0.0%
0.5%
1.0%
1.5%
2.0%
2.5%
3.0%
3.5%
4.0%
4.5%
5.0%
0 100 200 300 400 500
Rela
tive N
et
Change in
Specific
Weig
ht
Time (min.)
TGA Screening (1100°C, 1 bar, 100 mL/min. CO2)
60-40 SiC-ZrB2
50-50 SiC-ZrB2
30-70 SiC-ZrB2
0-100 SiC-ZrB2
Target Metric
k'' ≈ 6.0x10-8 g2 m-4 s-1
Oxidation time: 40,000 hours
Allowable recession:10 microns (guess)
𝑘𝑐 = Τ𝑥2 2𝑡𝑘𝑐: Parabolic rate constant (recession)
𝑘′′ = 𝑘𝑐 ∙ 2 Τ𝑀𝑂ത𝑉𝑍𝑂
2
𝑘′′: Parabolic rate constant (specific weight change)ത𝑉: Equiv. scale vol. 𝑀𝑂: At. mass O𝑍𝑂: Valence O
40% ZrB2 + 60% SiC
50% ZrB2 + 50% SiC
70% ZrB2 + 30% SiC
100% ZrB2 + 0% SiC
Composition (vol. %)
Manufacturing Process Flow Diagram
10
QC and Performance Testing
Defect detection Proof testing
Packaging
Ceramic welding Shell integration
Pressureless Sintering
Additive Manufacturing
Ceramic On-Demand Extrusion Controlled drying and debinding
Materials Preparation
Additives selection Mixing and milling Paste formulation
Attrition Mill Thinky Mixer Thinky Syringe Charger
Paste rheology
Manufacturing Process Flow Diagram
11
QC and Performance Testing
Defect detection Proof testing
Packaging
Ceramic welding Shell integration
Pressureless Sintering
Additive Manufacturing
Ceramic On-Demand Extrusion Controlled drying and debinding
Materials Preparation
Additives selection Mixing and milling Paste formulation
Additive Manufacturing (ZrB2 + 30 vol. % SiC)‣ Preliminary test prints
12
Test Bar2x2 array0.5 mm channel diameter1.0 mm wall thickness50 mm length
Manufacturing Process Flow Diagram
13
QC and Performance Testing
Defect detection Proof testing
Packaging
Ceramic welding Shell integration
Pressureless Sintering
Additive Manufacturing
Ceramic On-Demand Extrusion Controlled drying and debinding
Materials Preparation
Additives selection Mixing and milling Paste formulation
Hadron Technologies HT-12MF1-SV
Thermal Technology graphite furnaces
2.45 GHz, 12 kW
Manufacturing Process Flow Diagram
14
QC and Performance Testing
Defect detection Proof testing
Packaging
Ceramic welding Shell integration
Pressureless Sintering
Additive Manufacturing
Ceramic On-Demand Extrusion Controlled drying and debinding
Materials Preparation
Additives selection Mixing and milling Paste formulation
TIG
Hilmas GE, Fahrenholtz WG, Watts JL,
Brown-Shaklee HJ. Ceramic welds,
and a method for producing the
same. Patent No. US8715803 (2014).
a
d
b c
Manufacturing Process Flow Diagram
15
QC and Performance Testing
Defect detection Proof testing
Packaging
Ceramic welding Shell integration
Pressureless Sintering
Additive Manufacturing
Ceramic On-Demand Extrusion Controlled drying and debinding
Materials Preparation
Additives selection Mixing and milling Paste formulation
Zeiss Xradia X-ray Microscope
Manufacturing Process Flow Diagram
16
QC and Performance Testing
Defect detection Proof testing
Packaging
Ceramic welding Shell integration
Pressureless Sintering
Additive Manufacturing
Ceramic On-Demand Extrusion Controlled drying and debinding
Materials Preparation
Additives selection Mixing and milling Paste formulation
50 mm
5 mm
4x mag high-res sub-volume centered on
printed channel
45 mm
4.6 mm
Green body (as-printed)
After sintering at 2000°C (94% theoretical density)
X-ray Microscopy
Planned sCO2 Test Loop @ S&T
17
Heater 2
Heater 1Recuperator
ACC or WCC
CO2cylinder
with heater
Back-pressureregulator
Pump
WCC
Pressure-reducingregulator
WCC
P (MPa) | T (°C)
6.9 | 28
6.9 | 25
26.0 | 53
25.1 | 53 25.0 | 300 24.9 | 464
8.2 | 449
8.0 | 650
7.8 | 479
7.7 | 50
2.0 kW
1.2 kW
-2.6 kW
0.0
05
kg/
s
6.9 | 45
-0.9 kW0.15 kW
‣ Continuous flow loop, single metered flow, 2 kW thermal
‣ 8 MPa, 650°C on low-pressure side, 25 MPa on high-pressure side
‣ Liquid pumping loop based on footprint, budget (ca. $100k) and lab safety (ventilation) considerations
‣ Used for HX sub-scale testing, sCO2 materials compatibility studies, and proof/shakedown testing
Technology-to-Market Updates‣ Commercialization planning
– IP generation for disruptive materials and manufacturing technologies
• Applications outreach for extreme environment components
– Ceramic HX (via startup or contract manufacturing) – low commercial readiness level
• Requires identification of first markets with demonstrable near-term demand
• Requires de-risking of ceramics for critical or long duration applications:
– Materials database generation is costly (labor and time intensive)
– Must be preceded by scale-up to relevant scale of production, automation, etc.
• Cost model: baseline set by cost center approach using federally approved guidelines
– First prototype: $5730 ($45,000/UA)
» 20x cost reduction required (labor costs appear to be a driving factor) 18
Which comes first, the HX or
the application?
– Target at production scale: $260 ($2,000/UA)
Like
liho
od
Almost Certain
Likely
Moderate
Unlikely
Rare
Insignificant Minor Moderate Major Catastrophic
Consequences
Risk Update
Risk #
Ceramic AM properties 1
Ceramic welding 2
Materials compatibility 3
HX design (thermal stress) 4
Reliability 5
Cost-performance TEA 6
5 4
3
2 16
X
X
Now
Start of project
12 3
4
5
6
Progress Against Tasks – Timetable‣ Accomplishments:
– HX conceptual design shown to be viable (validated CFD/FEA model)
– Preliminary screening identifies compatible material for sCO2 operation
– Custom, dedicated ceramic AM machine built (still undergoing testing)
‣ What remains to be done?
– Material and manufacturing process optimization (40-50 weeks)
– Detailed HX design of flow headers and connections to sCO2 test loop (20-25 weeks)
– Procurement and commissioning of sCO2 test loop @ S&T (20-25 weeks)
‣ Primary challenges:
– COVID-19 disruptions to lab access and personnel recruitment
20
Potential Partnerships
‣ sCO2 test loop @ S&T can be made available to program teams starting mid-late 2021
‣ Project needs:
– Industry connections to assess case for need to further increase turbine inlet temperature and first downstream component (recuperator), as well as likelihood of ceramic HX technology adoption
– Consult with current generation sCO2 HX manufacturers regarding design solutions for robust (mechanically compliant) process connections at 700°C and 25 Mpa – avoid reinvention
‣ Anticipated needs beyond project period to successfully commercialize UHTC-based HX:
– First market application scenario to set specifications for HX scale and operating conditions
– Follow-on support for manufacturing technology improvements to support increased feature complexity, production scale-up, and materials database generation