Energy Efficient Polymers for Gas-Liquid Heat Exchangers

Abstract

The present study explores the thermofluid characteristics of a seawater-methane heat exchanger that could be used in the liquefaction of natural gas on offshore platforms. The compression process generates large amounts of heat, usually dissipated via plate heat exchangers using seawater as a convenient cooling fluid. Such an application mandates the use of a corrosion resistant material. Metals such as titanium, expensive in terms of both energy and currency, are a common choice. The “total coefficient of performance,” or COPT, which incorporates the energy required to manufacture a heat exchanger along with the pumping power expended over the lifetime of the heat exchanger, is used to compare conventional metallic materials to thermally conductive polymers. The results reveal that heat exchangers fabricated of low energy, low thermal conductivity polymers can perform as well as, or better than, those fabricated of conventional materials, over the full lifecycle of the heat exchanger. Analysis of a prototypical seawater-methane heat exchanger, built from a thermally conductive polymer, suggests that a COPT nearly double that of aluminum, and more than ten times that of titanium, could be achieved.