Experimental Study of a Set of Integrated Cross-Media Heat Exchangers (iCMHXs) for Liquid Cooling in Desktop Computers

Abstract

The present study is an experimental investigation of a set of five additively-manufactured compact, lightweight, low-cost, air-to-water cross-media heat exchangers suitable for liquid cooling applications in desktop computers, among other applications. The heat transfer between the two fluids is facilitated by solid metallic wires arranged in a staggered tube-bank configuration, in direct contact with both fluids separated by polymer walls. Since the liquid flows externally over the wires instead of flowing inside the tubes in conventional tube-bank fin heat exchangers, smaller wires can be used in iCMHXs, resulting in lighter and more efficient units. The additively-manufactured iCMHX units are post-processed using a conformal polyurethane sealant. The units are experimentally studied in two case studies based on their post-processing techniques. The experimental studies include instrumentation calibration as well as uncertainty analysis. The first case study considers three geometrically identical iCMHX units sharing the same post-processing method. The overall iCMHX performances characterized by the thermal and hydrodynamic parameters, such as thermal resistance and pressure drop for both waterside and airside, are compared. Their experimental results are also compared to 2D CFD predictions. To provide probable reasoning behind the differences in the comparisons, a second case study is then carried out by experimentally investigating two iCMHX units but with variable post-processing approaches such as by using a thinned sealant and by using a single layer of sealant.

Numerical and Experimental Study of a Novel Additively Manufactured Metal-Polymer Composite Heat-Exchanger for Liquid Cooling Electronics

“…However, ∆p w includes the pressure drop from the connecting flexible plastic tubes, the integrated top-bottom liquid-side manifolds, and the HX core. Thus, ∆p core w across the test section can be obtained by subtracting the extra pressure drop due to tubes and manifolds from measured ∆p w values, as mentioned in the authors' past study [24]. HX core pressure drop is observed to increase with the increasing flow rate in a quadratic manner, as shown in Figure 9.…”

“…This section validates the numerical study using experimental results for both waterside and air-side testing. The present numerical study is further compared with the authors' past numerical work [23,24].…”

“…The additively manufactured metal-polymer composite HX [23,24] comprises an HX core made of polymer and an array of metal wires, which act as fins for both air-side and liquid-side convective heat transfer, as shown in Figure 1. Metal wires can be arranged in a staggered or inline configuration.…”

“…HXs are additively manufactured in-house using a customized proprietary 3D printer. HXs are then post-processed by dip-coating them in polyurethane sealant to ensure leak-proof polymer-metal interfaces [24]. Post-processed HXs are then tested and modeled for heat transfer between hot and cold fluids.…”

A 1D Reduced-Order Model (ROM) for a Novel Latent Thermal Energy Storage System

“…The present study overcomes these challenges by utilizing a low-cost, metal-polymer composite heat exchanger (HX), consisting of metal wires embedded in the polymer structure and integrated with a PCM to yield a compact, durable, and lightweight storage device. The proposed technology leverages the results from the authors' past work on a patented cross-media approach capable of producing entirely additively manufactured, low-cost and lightweight metal-polymer composite heat exchangers [10][11][12][13][14]. The TES units based on these HXs utilize high thermal-conductivity continuous metal wires that act as fins in a tube-bank geometry, separated by lightweight and low-cost alternate polymer channels.…”