The Rise of Additive Manufacturing in Thermal Engineering
In recent years, additive manufacturing technologies have expanded into various industries, including the thermal management of electronics. As metal 3D printing techniques have improved and become more commercially viable, engineers are leveraging this innovative approach to create intricate cooling solutions, particularly heat exchangers.
One key advantage of additive manufacturing for heat exchangers is the potential for significant cost savings. Companies can reduce 15-20 individual part numbers and print them as a single component, eliminating the need for inventory, additional inspections, and assembly processes typically required with conventionally produced components. As noted by AdditiveMagazine.com, “Some envision AM (additive manufacturing) as a complement to foundational subtractive manufacturing (removing material like drilling out material) and to a lesser degree forming (like forging). Regardless, AM may offer consumers and professionals alike, the accessibility to create, customize and/or repair product, and in the process, redefine current production technology.”
The 3D printing process, developed at the Massachusetts Institute of Technology (MIT), is the most well-known form of additive manufacturing. Three-dimensional objects are created by building up multiple layers of material, which can be metal, plastic, concrete, living tissue, or other substances. This capability has encouraged creativity in industrial applications, as additive manufacturing enables the production of complex geometric shapes that would be impossible with standard manufacturing techniques. For example, heat exchangers can be printed as a single piece with scooped-out or hollow centers, providing enhanced strength and fewer weak spots compared to welded or attached components.
Unlocking the Potential of 3D-Printed Heat Exchangers
Heat exchangers are integral to effective thermal management, playing a crucial role in dissipating heat from electronics, automotive systems, aerospace applications, and a wide range of other industries. Compact heat exchangers are typically composed of thin, welded metal sheets, which can make their production both challenging and time-consuming. Additionally, the welding process adds weight to the final component.
By leveraging 3D printing techniques, manufacturers can produce heat exchangers more quickly, with reduced weight, and greater efficiency. In 2016, a Department of Energy-funded consortium of researchers developed a miniaturized air-to-refrigerant heat exchanger that was more compact and energy-efficient than existing market designs. The team, led by the Center for Environmental Energy Engineering (CEEE) and 3D Systems, increased the efficiency of a 1 kW heat exchanger by 20% while reducing its weight and size. The manufacturing cycle for this heat exchanger was reduced from months to weeks.
Another example of the benefits of 3D printing for heat exchangers comes from Fabrisonic, an Ohio-based company that uses a hybrid metal 3D printing process called Ultrasonic Additive Manufacturing (UAM). This technique merges layers of metal foil together in a solid state, using high-frequency ultrasonic vibrations, without the need for melting. Fabrisonic’s UAM process allows for the creation of complex, customized heat exchanger designs that can be scaled up to larger sizes, as confirmed by a report from NASA and Fabrisonic stating, “UAM heat exchanger technology developed under NASA JPL funding has been quickly extended to numerous commercial production applications. Channel widths range from 0.020 inch to greater than one inch with parts sized up to four feet in length.”
While 3D printing has made significant strides in the development of heat exchangers, there are still some challenges to overcome. Researchers at the University of Maryland highlighted the need to improve the cost-competitiveness of 3D-printed heat exchangers compared to traditional manufacturing techniques, as well as the difficulty in physically scaling up the technology. To address the scalability issue, the researchers suggest exploring modularization, where multiple smaller heat exchangers are arranged together to accomplish the same task, rather than attempting to produce a single, larger component.
Continuous Innovation in 3D-Printed Heat Exchanger Technology
Research and development efforts are ongoing around the world to further improve the 3D printing process and create increasingly complex, high-performance heat exchangers. For example, Conflux Technology, an additive manufacturing startup based in Australia, received significant funding to develop its technology specifically for heat exchange and fluid flow applications.
Another example is the work being done at the University of Wisconsin-Madison, which received a grant from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) to develop heat exchangers with “internal projections to increase turbulence and facilitate heat transfer. Such intricate shapes are impossible with traditional manufacturing.”
In 2018, Hieta Technologies, a U.K.-based company, partnered with the British metrology company Renishaw to commercialize its 3D-printed heat exchangers. Renishaw used its AM250 system to 3D print the heat exchanger walls as thin as 150 microns. The resulting samples were heat-treated and characterized, confirming the effectiveness of the laser powder bed fusion process. This approach allowed for a faster manufacturing cycle, a 30% reduction in weight, and a 30% decrease in volume, while still meeting the required heat transfer and pressure drop specifications.
Most recently, GE Research announced a multi-million-dollar program, led by the company, with Oak Ridge National Laboratory (ORNL) and the University of Maryland, to develop compact heat exchangers that can withstand temperatures up to 900°C and pressures as high as 250 bar. This initiative is funded by ARPA-E’s HITEMMP (High-Intensity Thermal Exchanger through Materials and Manufacturing Processes) program and involves the use of a novel nickel superalloy designed for high-temperature applications, as well as the development of biologically-inspired shapes to enhance heat exchanger efficiency.
These examples showcase the rapid advancements in 3D printing for thermal management applications, with researchers and engineers continuously pushing the boundaries of what is possible. From demonstrating the feasibility of 3D printing copper at the Fraunhofer Institute for Laser Technology ILT in Germany to developing methods for creating rough surfaces through additive manufacturing to enhance boiling heat transfer at Penn State (soon to be at MIT), the potential of this technology continues to evolve and expand.
The Future of Air-Cooled Heat Exchangers in Electronics Cooling
As the electronics industry continues to demand higher power and increased efficiency, the need for innovative thermal management solutions is more critical than ever. Air-cooled heat exchangers, with their ability to effectively dissipate heat without the added complexity of liquid cooling systems, remain a popular choice for many applications.
The advancements in additive manufacturing have opened up new avenues for designing and producing air-cooled heat exchangers that exceed the performance of traditional models. By leveraging the design freedom and customization capabilities of 3D printing, engineers can create intricate fin structures, optimize flow paths, and integrate complex geometries that enhance heat transfer while reducing weight and size.
Moreover, the rapid prototyping capabilities of additive manufacturing enable faster iterations and testing of heat exchanger designs, accelerating the development process and allowing for rapid optimization. This, in turn, helps manufacturers and end-users in the electronics industry to stay ahead of the curve, addressing the ever-evolving thermal management challenges posed by new technologies and system requirements.
As the industry continues to push the boundaries of what is possible, the role of air-cooled heat exchangers, particularly those produced through additive manufacturing, will become increasingly crucial in ensuring the efficient and reliable operation of critical electronic systems. By harnessing the power of these innovative thermal solutions, electronics manufacturers can enhance product performance, reduce energy consumption, and maintain the long-term integrity of their components and systems.
Conclusion
The thermal management of electronics has always been a critical challenge, and as power densities continue to increase, the need for advanced cooling solutions becomes more pressing. The rise of additive manufacturing has opened up new possibilities in the design and production of air-cooled heat exchangers, enabling engineers to create innovative, high-performance components that can meet the evolving demands of the electronics industry.
By leveraging the design freedom, cost-effectiveness, and rapid prototyping capabilities of 3D printing, manufacturers can develop air-cooled heat exchangers that are lighter, more efficient, and better suited to the specific needs of their applications. As research and development in this field continues to advance, the future of air-cooled heat exchangers in the electronics industry looks increasingly bright, with the potential to drive significant improvements in thermal management, energy efficiency, and overall system performance.
To explore the full range of air-cooled heat exchanger solutions available and discuss how they can benefit your electronics cooling challenges, I encourage you to visit https://www.aircooledheatexchangers.net/. Our team of thermal engineering experts is ready to work with you to identify the optimal air-cooled heat exchanger design and ensure your electronics operate at peak efficiency.
