Highly porous ceramic fiber insulations are beginning to be considered as a replacement for firebrick insulations in high temperature, high pressure applications by the chemical process industry. However, the implementation of such materials has been impeded by a lack of experimental data and predictive models, especially at high gas pressure. The goal of this work was to develop a general, applied thermophysical model to predict effective thermal conductivity, keff, of porous ceramic fiber insulation materials and to determine the temperature, pressure, and gas conditions under which natural convection is a possible mode of heat transfer. A model was developed which calculates keff as the sum of conduction, convection, and radiation partial conductivities. The model was validated using available experimental data, including laboratory measurements made by this research effort. Overall, it was concluded that natural convection is indeed possible for the most porous insulations at pressures exceeding 10 atm. Furthermore, keff for some example insulations was determined as a function of temperature, pressure, and gas environment.

References

References
1.
Pauken
,
M.
,
Li
,
L.
,
Almasco
,
D.
,
Del Castillo
,
L.
,
Van Luvender
,
M.
,
Beatty
,
J.
,
Knopp
,
M.
, and
Polk
,
J.
,
2011
, “
Insulation Materials Development for Potential Venus Surface Missions
,”
AIAA
Paper No. 2011-256.
2.
Daryabeigi
,
K.
,
2003
, “
Heat Transfer in High-Temperature Fibrous Insulation
,”
J. Thermophys. Heat Transfer
,
17
(
1
), pp.
10
20
.
3.
Nield
,
D.
, and
Bejan
,
A.
,
2006
,
Convection in Porous Media
,
3rd ed.
,
Springer
,
New York
.
4.
Bejan
,
A.
, and
Kraus
,
A. D.
,
2003
, “
Porous Media
,”
Heat Transfer Handbook
,
Wiley
,
Hoboken, NJ
.
5.
Bejan
,
A.
, and
Khair
,
K. R.
,
1985
, “
Heat and Mass Transfer by Natural Convection in a Porous Medium
,”
Int. J. Heat Mass Transfer
,
28
(
5
), pp.
909
918
.
6.
Bejan
,
A.
,
Dincer
,
I.
,
Lorente
,
S.
,
Miguel
,
A. F.
, and
Reis
,
A. H.
,
2004
,
Porous and Complex Flow Structures in Modern Technologies
,
Springer-Verlag
,
New York
.
7.
Kaviany
,
M.
,
1995
,
Principles of Heat Transfer in Porous Media
,
2nd ed.
,
Springer
,
New York
.
8.
Bhattacharya
,
R.
,
1980
, “
Heat Transfer Model for Fibrous Insulations
,”
Thermal Insulation Performance
,
D.
McElroy
and
R.
Tye
, eds.,
American Society for Testing and Materials
,
Philadelphia, PA
, pp.
272
286
.
9.
Ferkl
,
P.
,
Pokorný
,
R.
,
Bobák
,
M.
, and
Kosek
,
J.
,
2013
, “
Heat Transfer in One-Dimensional Micro- and Nano-Cellular Foams
,”
Chem. Eng. Sci.
,
97
, pp.
50
58
.
10.
Prasad
,
V.
, and
Kulacki
,
F.
,
1985
, “
Natural Convection in Porous Media Bounded by Short Concentric Vertical Cylinders
,”
ASME J. Heat Transfer
,
107
(
1
), pp.
147
154
.
11.
Stark
,
C.
, and
Fricke
,
J.
,
1993
, “
Improved Heat-Transfer Models for Fibrous Insulations
,”
Int. J. Heat Mass Transfer
,
36
(
3
), pp.
617
625
.
12.
Litovsky
,
E.
,
Shapiro
,
M.
, and
Shavit
,
A.
,
1996
, “
Gas Pressure and Temperature Dependences of Thermal Conductivity of Porous Ceramic Materials: Part 2, Refractories and Ceramics With Porosity Exceeding 30%
,”
J. Am. Ceram. Soc.
,
79
(
5
), pp.
1366
1376
.
13.
Daryabeigi
,
K.
,
Cunnington
,
G. R.
, and
Knutson
,
J. R.
,
2011
, “
Combined Heat Transfer in High-Porosity High-Temperature Fibrous Insulation: Theory and Experimental Validation
,”
J. Thermophys. Heat Transfer
,
25
(
4
), pp.
536
546
.
14.
Zhao
,
S.
,
Zhang
,
B.
, and
He
,
X.
,
2009
, “
Temperature and Pressure Dependent Effective Thermal Conductivity of Fibrous Insulation
,”
Int. J. Therm. Sci.
,
48
(
2
), pp.
440
448
.
15.
Kamiuto
,
K.
,
Kinoshita
,
I.
,
Miyoshi
,
Y.
, and
Hasegawa
,
S.
,
1982
, “
Experimental Study of Simultaneous Conductive and Radiative Heat Transfer in Ceramic Fiber Insulation
,”
J. Nucl. Sci. Technol.
,
19
(
6
), pp.
460
468
.
16.
Hayashi
,
K.
,
1984
, “
Thermal Conductivity of Ceramic Fibrous Insulators at High Temperatures
,”
Int. J. Thermophys.
,
5
(
2
), pp.
229
238
.
17.
Zheng
,
G.
,
Verret
,
A.
,
Burke
,
N.
,
Prescott
,
N.
,
Cai
,
D.
, and
Perera
,
R.
,
2001
, “
An Update on Heat Transfer in a Porous Insulation Medium in a Subsea Bundled Pipeline
,”
ASME J. Energy Res. Technol.
,
123
(
4
), pp.
285
290
.
18.
Kurtbas
,
I.
, and
Celik
,
N.
,
2009
, “
Experimental Investigation of Forced and Mixed Convection Heat Transfer in a Foam-Filled Horizontal Rectangular Channel
,”
Int. J. Heat Mass Transfer
,
52
(
5–6
), pp.
1313
1325
.
19.
Bhattacharya
,
A.
, and
Mahajan
,
R. L.
,
2006
, “
Metal Foam and Finned Metal Foam Heat Sinks for Electronics Cooling in Buoyancy-Induced Convection
,”
ASME J. Electron. Packag.
,
128
(
3
), pp.
259
266
.
20.
Bejan
,
A.
, and
Kraus
,
A. D.
,
2003
,
Heat Transfer Handbook
,
Wiley
,
New York
.
21.
Otero
,
J.
,
Dontcheva
,
L. A.
,
Johnston
,
H.
,
Worthing
,
R. A.
,
Kurganov
,
A.
,
Petrova
,
G.
, and
Doering
,
C. R.
,
2004
, “
High-Rayleigh-Number Convection in a Fluid-Saturated Porous Layer
,”
J. Fluid Mech.
,
500
, pp.
263
281
.
22.
Kamiuto
,
K.
,
1991
, “
Analytical Expression for Total Effective Thermal Conductivities of Packed Beds
,”
J. Nucl. Sci. Technol.
,
28
(
12
), pp.
1153
1156
.
23.
Siegel
,
R.
, and
Howell
,
J. R.
,
2002
,
Thermal Radiation Heat Transfer
,
4th ed.
,
Taylor and Francis
,
New York
.
24.
Van de Hulst
,
H. C.
,
1957
,
Light Scattering by Small Particles
,
Dover
,
New York
.
25.
Kerker
,
M.
,
1969
,
The Scattering of Light, and Other Electromagnetic Radiation
,
Academic
,
New York
.
26.
Leachman
,
J.
,
Jacobsen
,
R.
,
Penoncello
,
S.
, and
Lemmon
,
E.
,
2009
, “
Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen
,”
J. Phys. Chem. Ref. Data
,
38
(3), pp.
721
748
.
27.
McCarty
,
R.
, and
Arp
,
V.
,
1990
, “
A New Wide Range Equation of State for Helium
,”
Adv. Cryog. Eng.
,
35
, pp.
1465
1475
.
28.
Arp
,
V.
,
McCarty
,
R.
, and
Friend
,
D.
,
1989
, “
Thermophysical Properties of Helium-4 From 0.8 to 1500 K With Pressures to 2000 MPa
,” National Institute of Standards and Technology, Boulder, CO, Technical Report No. N-90-28681.
29.
Hands
,
B.
, and
Arp
,
V.
,
1981
, “
A Correlation of Thermal Conductivity Data for Helium
,”
Cryogenics
,
21
(
12
), pp.
697
703
.
30.
Span
,
R.
,
Lemmon
,
E.
,
Jacobsen
,
R.
,
Wagner
,
W.
, and
Yokoezki
,
A.
,
2000
, “
A Reference Equation of State for the Thermodynamic Properties of Nitrogen for Temperatures From 63.151 to 1000 K and Pressures to 2200 MPa
,”
J. Phys. Chem. Ref. Data
,
29
(
6
), pp.
1361
1433
.
31.
Lemmon
,
E.
, and
Jacobsen
,
R.
,
2004
, “
Viscosity and Thermal Conductivity Equations for Nitrogen, Oxygen, Argon, and Air
,”
Int. J. Thermophys.
,
25
(
1
), pp.
21
69
.
32.
Tegler
,
R.
,
Span
,
R.
, and
Wagner
,
W.
,
1997
, “
Eine neue fundamental-gleichung für das fluide zustandsgebiet von argon für temperaturen von der schmelzlinie bis 700 K und drücke bis 1000 MPa
,”
Fortschr.-Ber. Verfahrenstech.
,
3
(
480
).
33.
Lemmon
,
E.
,
Jacobsen
,
R.
,
Penoncello
,
S.
, and
Friend
,
D.
,
2000
, “
Thermodynamic Properties of Air and Mixtures of Nitrogen, Argon, and Oxygen From 60 to 2000 K at Pressures to 2000 MPa
,”
J. Phys. Chem. Ref. Data
,
29
(
3
), pp.
331
385
.
34.
Span
,
R.
, and
Wagner
,
W.
,
1996
, “
A New Equation of State for Carbon Dioxide Covering the Fluid Region From the Triple-Point Temperature to 1100 K at Pressures up to 800 MPa
,”
J. Phys. Chem. Ref. Data
,
25
(
6
), pp.
1509
1596
.
35.
Vesovic
,
V.
,
Wakeham
,
W.
,
Olchowy
,
G.
,
Sengers
,
J.
,
Watson
,
J.
, and
Millat
,
J.
,
1990
, “
The Transport Properties of Carbon Dioxide
,”
J. Phys. Chem. Ref. Data
,
19
(
3
), pp.
763
808
.
36.
Fenghour
,
A.
,
Wakeham
,
W.
, and
Vesovic
,
V.
,
1998
, “
The Viscosity of Carbon Dioxide
,”
J. Phys. Chem. Ref. Data
,
27
(
1
), pp.
31
44
.
37.
Gembarovic
,
J.
, and
Taylor
,
R.
,
2007
, “
A Method for Thermal Diffusivity Determination of Thermal Insulators
,”
Int. J. Thermophys.
,
28
(
6
), pp.
2164
2175
.
You do not currently have access to this content.