Minimum Mass Polymer Seawater Heat Exchanger for LNG Applications

Abstract

The present study explores the thermofluid characteristics of a corrosion-resistant, thermally enhanced polymer composite, seawater-methane heat exchanger module for use in the liquefaction of natural gas on offshore platforms. Several metrics, including the heat transfer rate, the mass-specific heat transfer rate, and the total coefficient of performance (COPT), are used to compare the thermal performance of polymer composites having a range of thermal conductivities with that of corrosion-resistant metals. For operating conditions considered typical of the natural gas liquefaction industry in the Persian Gulf, a 10 W/m K polymer composite is found to provide nearly identical heat transfer rate to that of a corrosion-resistant titanium heat exchanger, almost 50% higher mass-specific heat transfer than for titanium (at 200 W pumping power), and COPT values approximately twice that of a least-material titanium heat exchanger. The results contribute to establishing the viability of using polymer composites for gas-liquid heat exchanger applications involving seawater and other corrosive fluids.