The compression process necessary for the liquefaction of natural gas on offshore platforms generates large amounts of heat, usually dissipated via sea water cooled plate heat exchangers. To date, the corrosive nature of sea water has mandated the use of metals, such as titanium, as heat exchanger materials, which are costly in terms of life cycle energy expenditure. This study investigates the potential of a commercially available, thermally conductive polymer material, filled with carbon fibers to enhance thermal conductivity by an order of magnitude or more. The thermofluid characteristics of a prototype polymer seawater-methane heat exchanger that could be used in the liquefaction of natural gas on offshore platforms are evaluated based on the total coefficient of performance $(COPT)$, which incorporates the energy required to manufacture a heat exchanger along with the pumping power expended over the lifetime of the heat exchanger, and compared with those of conventional heat exchangers made of metallic materials. The heat exchanger fabricated from a low energy, low thermal conductivity polymer is found to perform as well as, or better than, exchangers fabricated from conventional materials, over its full lifecycle. The analysis suggests that a $COPT$ nearly double that of aluminum, and more than ten times that of titanium, could be achieved. Of the total lifetime energy use, 70% occurs in manufacturing for a thermally enhanced polymer heat exchanger compared with 97% and 85% for titanium and aluminum heat exchangers, respectively. The study demonstrates the potential of thermally enhanced polymer heat exchangers over conventional ones in terms of thermal performance and life cycle energy expenditure.

1.
Sims
,
R. E. H.
,
Schock
,
R. N.
,
Adegbululgbe
,
A.
,
Fenhann
,
J.
,
Konstantinaviciute
,
I.
,
Moomaw
,
W.
,
Nimir
,
H. B.
, and
Schlamadinger
,
B.
, 2007, “
Energy Supply
,”
Climate Change: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change
,
Cambridge University Press
,
Cambridge, UK
.
2.
Metz
,
B.
,
Davidson
,
O. R.
,
Bosch
,
P. R.
,
Dave
,
R.
, and
Meyer
,
L. A. E.
, 2007, “
Summary for Policymakers
,”
Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change
,
Cambridge University Press
,
Cambridge, UK
.
3.
Bar-Cohen
,
A.
,
Rodgers
,
P.
, and
Cevallos
,
J.
, 2008, “
Application of Thermally Conductive Thermoplastics to Seawater-Cooled Liquid-Liquid Heat Exchangers
,”
Fifth European Thermal-Sciences Conference
, Eindhoven, The Netherlands.
4.
Kampf
,
J.
, and
Sadrinasab
,
M.
, 2006, “
The Circulation of the Persian Gulf: A Numerical Study
,”
Ocean Science
,
2
, pp.
27
41
, available at: http://www.ocean-sci.net/2/27/2006/http://www.ocean-sci.net/2/27/2006/.
5.
Bar-Cohen
,
A.
,
Bahadur
,
R.
, and
Iyengar
,
M.
, 2006, “
Least-Energy Optimization of Air-Cooled Heat Sinks for Sustainability—Theory, Geometry and Material Selection
,”
Energy
0360-5442,
31
, pp.
579
619
.
6.
Bar-Cohen
,
A.
, and
Iyengar
,
M.
, 2002, “
Design and Optimization of Air-Cooled Heat Sinks for Sustainable Development
,”
IEEE Trans. Compon. Packag. Technol.
1521-3331,
25
, pp.
584
591
.
7.
Japan Aluminum Association
, 1999, Summary of Inventory Data, LCA (Life Cycle Assessment) Committee Report.
8.
Kampe
,
S. L.
, 2001, “
Incorporating Green Engineering in Materials Selection and Design
,”
Proceedings of the 2001 Green Engineering Conference: Sustainable and Environmentally-Conscious Engineering
, Roanoke, VA.
9.
Suzuki
,
T.
, and
Takahashi
,
J.
, 2005, “
Prediction of Energy Intensity of Carbon Fiber Reinforced Plastics for Mass-Produced Passenger Cars
,”
Ninth Japan International SAMPE Symposium JISSE-9
, Tokyo, Japan.
10.
Nielsen
,
L. E.
, 1974, “
The Thermal and Electrical Conductivity of Two-Phase Systems
,”
Ind. Eng. Chem. Fundam.
0196-4313,
13
(
1
), pp.
17
20
.
11.
Bar-Cohen
,
A.
, and
Bahadur
,
R.
, 2006, “
Characterization and Modeling of Anisotropic Thermal Conductivity in Polymer Composites
,”
ASME International Mechanical Engineering Congress and Exposition
.
12.
N. M.
Mohamed
, 2007, private communication, ADGAS.
13.
Natural Gas Background
, 2004, Natural Gas Supply Association, http://www.naturalgas.org/overview/background.asphttp://www.naturalgas.org/overview/background.asp, last accessed Feb. 13 2008.
14.
Physical Properties of Seawater
, 2009, Kaye and Laby Online, http://www.kayelaby.npl.co.uk/general_physics/2_7/2_7_9.htmlhttp://www.kayelaby.npl.co.uk/general_physics/2_7/2_7_9.html, last accessed Feb. 13, 2009.
15.
Wang
,
L.
,
Sundén
,
B.
, and
Manglik
,
R. M.
, 2007,
Plate Heat Exchangers: Design, Applications and Performance
,
WIT
,
Billerica, MA
.
16.
Hart
,
G. K.
,
Lee
,
C. -O.
, and
Latour
,
S. R.
, 1979,
Development of Plastic Heat Exchangers for Ocean Thermal Energy Conversion
,
DSS Engineers
,
Fort Lauderdale, FL
.
17.
Cool Polymers Thermally Conductive Polymers
, 2010, http://www.coolpolymers.com/http://www.coolpolymers.com/, last accessed Jan. 29.
18.
Incropera
,
F.
, and
DeWitt
,
D.
, 2002,
Introduction to Heat Transfer
,
Wiley
,
New York
.
19.
Sieder
,
E. N.
, and
Tate
,
G. E.
, 1936, “
Heat Transfer and Pressure Drop of Liquids in Tubes
,”
Ind. Eng. Chem.
0019-7866,
28
(
12
), pp.
1429
1435
.
20.
Gnielinski
,
V.
, 1976, “
New Equations for Heat and Mass Transfer in Turbulent Pipe and Channel Flow
,”
Int. Chem. Eng.
0020-6318,
16
, pp.
359
368
.
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