Session: 12-21-01: Multiphase Flow

Paper Number: 166612

Design Improvement of a 3D Printed Polymer Heat Exchanger As a Regenerator for an Indirect Evaporative Cooler 

The use of an indirect evaporative cooling system (IDEC) allows for the cooling of air without an increase in moisture through the use of a regenerative heat exchanger, which contains dry and wet channels. Conventional indirect evaporative cooling systems include wick layers and a pumped water circulation loop in the wet channels. Implementation of these components in IDEC imposes a limitation in heat exchanger design and flow configuration adding to the overall system complexity. In a recent study, the use of a 3D printed polymer heat exchanger and mist generator was explored for an indirect evaporative cooling system (Meler and Park, 2025). The novel counter-flow heat exchanger design and a mist chamber allowed for a simpler overall system. However, during the testing of the IDEC system, two significant issues have been uncovered with the previous design: (1) maldistribution of flow within the heat exchanger affecting its performance and (2) incomplete mixing of air in the mist chamber preventing some wet channels from operating at fully saturated conditions.

While an actual heat exchanger in common applications does not necessarily operate under uniform flow conditions, it is generally desirable to have a uniform flow and uniform inlet thermal condition for overall performance improvement. This paper will seek to understand the causes and effects of flow maldistribution and the lack of saturated air from incomplete mixing within the mist chamber of an IDEC with mist generation. A counterflow heat exchanger has an inherent challenge in flow manifold design for the separation of two flows at the inlet and outlet. Design modifications with heat exchanger and mist chamber will be explored to address these shortcomings. Furthermore, the effects of added thermal loading to the system performance by fan and ultrasonic mist generators will be evaluated. Efforts from this research will contribute to an improved understanding of additively manufactured heat exchanger designs and common issues that arise from the use of a mist chamber in an IDEC.

This study explores one of the possible applications of 3D printed polymer heat exchangers. The findings will lead to further improvements on the heat exchanger design, which can exploit the advantage of additive manufacturing in design freedom. For example, counterflow regenerator heat exchanger can be used in various applications. Also, composite materials can be used for 3D printing for improved thermal and mechanical properties. While the current 3D printing capability limits the size of the heat exchanger due to the filament spool size, it is possible to modularize the design for scaling up to a larger core size.

Presenting Author: Younggil Park Florida Polytechnic University

Presenting Author Biography: Younggil Park is an associate professor of Mechanical Engineering at Florida Polytechnic University. His research research interests are compact heat exchangers and thermal systems.

Authors:

Dominic Meler Florida Polytechnic University
Younggil Park Florida Polytechnic University