Typical commercially available polymeric heat exchangers are made of polymer tubes with diameters ranging from 5 to 50 mm and wall thicknesses of 3 mm. Unlike these, polymeric hollow fiber heat exchangers (PHFHE), developed at the Heat Transfer and Fluid Flow Laboratory, represent an innovation with a heat exchange surface consisting of polymer fibers with diameters of about 1 mm and a wall thickness of only 10% of the outer diameter. These heat exchangers have thousands of such microtubes, significantly increasing the heat transfer area.

Polymers are generally not considered as good thermal conductors, but very thin walls of the fibers and the large heat transfer area allow PHFHE to compete with metal heat exchangers in terms of heat transfer efficiency. The thermal efficiency and overall heat transfer coefficients of PHFHE are comparable to their metal counterparts. An additional advantage of polymer heat exchangers is their electrical insulating properties, making them ideal for use in electrical devices.

The smooth surfaces of the polymer fibers provide exceptional resistance to fouling, as confirmed in both air-liquid and liquid-liquid systems. Fouling on polymer tubes occurs four times slowly than on louvered fins of a similar size. Moreover, fouling is easily removed from the smooth surfaces of polymer fibers due to their weak adhesion properties.

Despite the thin walls (about 0.1 mm), hollow fibers can withstand high pressures reaching 50-150 bar, thanks to the small diameter of the microchannel.

Environmental friendliness is another significant advantage of polymer heat exchangers. Their production requires significantly less energy compared to metal counterparts, and they are easily recyclable. The carbon footprint of PHFHE is approximately seven times smaller than aluminum heat exchangers of the same weight. This makes PHFHE a more eco-friendly option for cooling systems. These heat exchangers not only provide efficient heat exchange but also help reduce environmental impact.

More information is available at:
https://www.heatlab.cz/research/polymeric-heat-exchangers-with-hollow-fibres/