Metal AM in Motion: How Velo3D is Redefining Heat Exchangers

by | February 25, 2022 | Business Drivers

One of the beautiful things about Velo3D’s advanced metal additive manufacturing (AM) is its ability to transform how entire industries produce core parts. From the energy sector to space and beyond, the applications for AM are broad and adaptable to the needs of specific industries.

When we talk about metal AM, it can sometimes be easier to speak about the large-scale implications this technology can have on entire industries; from producing better parts with more complex geometries, to metal AM’s ability to disrupt the old models of supply chains. In taking this long view, however, we miss the real-world success stories of speaking about specific applications for Velo3D’s advanced, end-to-end metal AM system.

In this article we’ll discuss one core part—the heat exchanger—what they are, why they present such a challenge for traditional manufacturing, and how metal AM is transforming them in both design and production.

What Are Heat Exchangers?

Heat exchangers represent a broad category of core parts used in countless applications from home appliances to jet engines. As their name suggests, heat exchangers work to transfer heat from one source — typically a liquid or a gas — to another, cooler liquid or gas source without those two sources having to mix. The purpose of heat exchangers is to allow engines and other machinery to operate efficiently without overheating.

There are a number of varieties of heat exchanger designs, including plate and fin, shell and tube, tube and tube, and more; all of which have unique benefits, applications, and design geometries.

What Makes Heat Exchangers So Difficult to Manufacture?

Heat exchangers present a unique challenge for engineers on both the design and manufacturing fronts.

In design, heat exchangers require maximal surface area between the hot and cool side of the part; the walls separating them also need to be as thin as possible to allow for as much heat transfer as possible, all while keeping the sides leak tight.

There is also a balance that must be achieved between the roughness of the surface necessary to transfer heat and the resulting pressure drop that occurs with varying texture differences. In the end, engineers are confronted with the challenge of producing exchangers with complex internal channels and thin, high aspect ratio walls.

The next challenge is reproducing these complex designs in manufacturing.

Traditionally, heat exchangers can be made of dozens of separate parts: core sheets, nose pieces, multiple fins and manifolds, and more. These pieces must  be manufactured separately — oftentimes requiring different manufacturing techniques like casting and forging — and then finally brazing and welding them all together into a single core part.

This process is labor intensive and timely, often requiring lead times of 12-18 months per design iteration.

Additionally, heat exchangers need to be optimized to reduce weight, particularly when applied to aerospace and aviation use cases. Having dozens of disparate parts joined together adds weight to the end part which can affect overall engine performance.

Conventional additive manufacturing systems, while an improvement on more conventional production, has its own limitations.

To reach the level of complexity of interior channel geometry necessary for the end application, conventional AM solutions often require support structures in the printing process. These internal supports are difficult to extract in post-processing—if they can be extracted at all—which not only threatens part viability but lengthens lead times as well.

Printing without the use of supports for internal channels typically leads to poor surface finish and an increase in back pressure for the heat exchanger. Additionally, thin metal parts tend to crack if not properly printed with the right parameter sets. They can interfere with the act of recoating—a process where a blade physically scrapes a fresh layer of powder on top of the part—and cause damage to the part or recoater blade, which in turn can crash the build or disrupt printing equipment.

Building Better Heat Exchangers With Advanced Metal AM

Truly tackling the design and manufacturing challenges presented by heat exchangers requires an end-to-end solution that merges design and manufacturing; it’s the reason why Velo3D is at the forefront of revolutionizing heat exchanger production.

By presenting a synergy of advanced design software and next-generation metal 3D printing, Velo3D is able to achieve the complexity of design in the build phase without compromising design intent.

Through our exclusive Flow™ pre-print software, we’re able to automatically assign the right parameter set to the different features of the heat exchanger. Thin metal fins, leak-tight channels, thicker structural parts, all receive different, specialized parameter sets optimized to print those geometries. Flow™ prescribes the optimal process to build the whole part, consolidating the myriad of parts typically used and eliminating the labor and time needed for assembly. These instructions are then fed to the printer for execution.

Using Velo3D’s Sapphire printers, engineers can achieve the complexity needed to hit key performance metrics required for even the most advanced applications in aviation and aerospace.

Part of what makes the Velo3D printing process so unique is our ability to manufacture parts without the need for intensive support structures. Additionally, Sapphire printers are able to achieve high, thin walls and low angles necessary to transfer heat. By using a specialized non-contact recoater system, the Sapphire can print thin walls without the risk of part or printer damage. The Sapphire refreshes the powder bed without making any contact with the part through a proprietary and contact-less process.

The resulting heat exchangers produced through the Velo3D process can achieve up to a 60 percent higher effective surface area and a 6x reduced pressure drop compared to existing parts.

The Velo3D end-to-end solution also reduces, and often eliminates, the need for multiple parts to be manufactured and brazed or welded together, or the need for intensive post-processing endemic to conventional metal AM systems, which means parts can be produced in as little as four weeks.

The design and production of heat exchangers is undergoing a renaissance right now. These core parts are being reinvented in a way that hasn’t been seen since the 1940s. The innovation on display in advanced metal AM is enabling the production of parts with more efficient, lightweight designs capable of transforming countless industries.

Are you interested in learning more about Velo3D’s advanced metal AM solution? Get in touch with one of our experts today to see how we’re revolutionizing manufacturing.

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About the Author

Amir Iliaifar

Director of Content

Amir Iliaifar is the Director of Content at Velo3D where he oversees the production and distribution of Velo3D’s global digital content marketing initiatives. Prior to joining the company, Amir worked for a leading professional drone manufacturer, several SaaS companies, and as an automotive tech journalist. He holds a Master of Arts in Digital Communication from the University of North Carolina at Chapel Hill.