Additive Manufactured Heat Exchangers

Effects on Pressure Drop when Additively Manufacturing Heat Exchangers with Micro-Geometries

Undergraduate research study conducted in 2019 through the Power Optimization of Electro-Thermal Systems (POET) and Air Conditioning and Refrigeration Center (ACRC) at The University of Illinois Urbana-Champaign under the supervision of

Problem Statement

The electrification of vehicles is on the rise, and it is expected that millions of EVs will be manufactured over the next decade. Developing effecive battery thermal management systems is critical in ensuring long-lasting, safe batteries. Additive manufacturing (AM) has been investigated for the rapid prototyping of heat exchangers (HXs). However, can AM be relied upon to create prototype heat exchangers with comparable properties to conventionally-made HXs?

Objectives

• Study the limitations of Direct Metal Laser Melting (DMLM)
• Increase the quality of DMLM-made HXs
• Achieve low pressure drops across HXs

Methods

A literature review informed the design of heat exchanger, ensuring all surfaces could be built upon and that round microchannels would be formed within the body of the HX. Three HXs were printed using different metals, and a pressure rig was built to control and measure the pressure differential across the HXs.

Results

AM results in HXs with low compliance, high roughness, and high porosity. As shown in a CT scan, the inner channels have high variability and roughness, both being detrimental to the pressure drop. Additionally, the porosity resulted in air and water escaping through the walls of the HX.