Polymeric Hollow Fiber Heat Exchangers (PHFHEs): A New Type of Compact Heat Exchanger for Lower Temperature Applications

Abstract

Plastic heat exchangers are characterized by an inferior thermal performance compared to their metal counterparts. Therefore, their usage is mainly limited to handling corrosive media or when ultra high purity is required, e.g., pharmaceutical industry. Polymeric Hollow Fiber Heat Exchangers (PHFHEs) have recently been proposed [1] as a new type of heat exchanger that can overcome these constraints and offer the same or better thermal performance than metallic shell and tube or plate heat exchangers while occupying a much smaller volume. In this paper we report our results for heat transfer in PHFHEs with both parallel and cross flow in the shell side of the device. Fibers made of polypropylene (PP) and polyetheretherketone (PEEK) were tested. In addition, steam condensation studies in PHFHEs are reported for the first time. The overall heat transfer coefficients achieved for water-water and water-brine systems are as high as 1400 Wm−2K−1. These values are higher than any value reported for plastic heat exchangers and comparable with commonly acceptable design values for metal shell and tube heat exchangers. Similar coefficients were obtained for steam condensation. Polymeric hollow fiber heat exchangers can also achieve high thermal effectiveness, large number of transfer units (NTU) and very small height of a transfer unit (HTU), if properly rated. If designed like commercial membrane contactors, they can achieve up to 12 transfer units in a single device, not longer than 60–70 cm! In addition, the conductance per unit volume PHFHEs achieved was up to one order of magnitude higher compared to metal heat transfer equipment. This superior thermal performance is also accompanied by considerably lower pressure drops. Therefore, the operation of PHFHEs will be characterized by a low operating cost. Combined with the much lower cost, lower weight and elimination of metal contamination polymer materials offer, it is obvious that PHFHEs constitute a potential substitute for metal heat exchangers on both thermal performance and economical grounds. Possible application fields include the food, pharmaceutical and biomedical industries as well as applications where corrosion resistant, light and very efficient devices are required, i.e., desalination, solar and offshore heat transfer applications.

Experimental characterization of heat transfer in an additively manufactured polymer heat exchanger

“…A list of the measurement equipment is shown in Table 2 with the corresponding accuracies. Based on the method explained in NIST Technical Note 1297 [40], the uncertainty of calculated quantity ( ) which is a function of , , … , with uncertainty of , , … , can be calculated as: (15) Using this method, the uncertainties for all heat exchanger performance parameters ( , , , ∆ ) were calculated, and the error bars are included in the results presented in the next sections.…”

“…Another common type of polymer heat exchanger is the polymeric hollow fiber heat exchanger [1,[14][15][16][17].…”

Recent research developments in polymer heat exchangers – A review

“…Zarkadas and Sirkar 74,75 reported polymeric hollow fibre heat exchangers (PHFHE) for low temperature (up to 150-200•C) and low pressure applications (test rig as shown in Figure 19). Polypropylene (PP), polyetheretherketone (PEEK) and asymmetric polyethersulfone (PES) hollow fibres have been used to manufacture heat exchangers.…”

The influence of hollow fibers orientation inside the polymeric hollow fiber heat exchanger on the heat transfer intensity

“…1) is one of the different types of polymer heat exchanger (Astrouski, 2012). Using thin-wall polymeric hollow fibers as heat exchanger tubes was first proposed by Zarkadas (2005) as a new type of heat exchanger for lower temperature/pressure applications. This heat exchanger utilizes polymeric microchannels as the heat transfer surface.…”