Energy: where 3D metal printing fits into turbomachinery and heat exchangers

The energy sector was among the first to seriously adopt additive manufacturing in metal, and for a rather unromantic reason: the parts are expensive, made of difficult alloys, produced in short runs, and have enormous downtime costs. These are the four factors that make this technology profitable.

These are the families where he fits in today, and why.

1. Compact heat exchangers

It's the star application and the one with the least debate. A conventional heat exchanger is manufactured by stacking plates or assembling bundles of tubes, and each joint is a potential leak, a point of corrosion, and a shape limitation.

Printed, the heat exchanger comes out as a single part, with the two circuits intertwined, the wall between them as thin as the pressure allows, and a heat exchange surface per unit volume that no other technology can match. The benefits:

• Less volume and weight for the same thermal output.
• No joints, and therefore no common failure mode.
• Curved paths, adapted to the available space in the installation instead of the other way around.

The structures with minimal surface area—gyroids and their family—are found here; they are explained in lattices. And the practical limitation is also present: if the fluid contains particles or encrusts, a two-millimeter channel that cannot be cleaned is a problem, not an advantage. This technology excels with clean fluids; with dirty fluids, it requires careful consideration.

2. Burners and injectors

Nozzles, burner heads, gas distributors. These are parts with complex internal channels, often with thin walls and internal cooling, which are now manufactured by machining and welding several parts.

Consolidating them into a single part—which is what's described in consolidating an assembly—eliminates welds in the hottest area of the equipment, which is precisely where they're least desirable. And it allows for mixing fuel and air with geometries that were previously impossible to manufacture, which is driving the redesign of burners for hydrogen and mixtures.

3. Impellers, diffusers and vanes

Compressor and pump impellers, diffusers, vane rings. Parts with warped surfaces where five-axis machining is slow, expensive, and sometimes impossible due to accessibility between vanes.

Here, additive manufacturing truly competes in prototypes and short production runs: a new impeller produced in two weeks instead of two months completely changes the pace of machine development. In long production runs, however, casting still wins in terms of unit cost.

word of caution: The surface quality of the inter-blade grooves is very important for performance, and it's usually the surface that's hardest to reach with tooling. Post-processing—including internal finishing by abrasive or chemical means—is not optional for this part. It's in post-processing.

4. Spare parts for old plants

The least glamorous, but probably the most profitable, scenario. A power plant, a chemical plant, or a paper mill has thirty- or forty-year-old equipment whose manufacturer no longer exists, or no longer produces that specific part. When that part fails, the alternative is a special order with lead times of months and an absurdly high minimum order quantity, or the plant shuts down.

Manufacturing the part from a blueprint, or from a scan of the broken part, solves a problem that currently costs a fortune each time it occurs. It's the same argument used for distributed spare parts manufacturing, applied to a sector where an hour of downtime translates into tens of thousands of euros.

Caution: A replacement part in pressure equipment or a classified area must meet the same requirements as the original, and that includes material and process qualification. It's not about "printing the part," it is about qualifying it.

5. Hydrogen

This is the fastest growing area. Bipolar plates, distributors, heat exchangers for battery cooling circuits, electrolyzer components. Very fine and highly repeated channel geometries, in corrosion-resistant alloys, in quantities that are still under development and not yet in production.

This is the exact profile where this technology is competitive today, and where volume will grow with the sector.

What materials are used

The comparison between the first three is in 316L, Inconel 718 or Ti-6Al-4V, and the complete catalog, in materials.

The three limits to keep in mind

Size. The build volume of an LPBF machine limits the size of the part. Many power components are large, and the solution is to consolidate them into modules that are then joined together, or not to use this technology at all.

Regulations. Pressure equipment, explosive atmospheres, regulated sectors. The part must be qualified and the process documented. This isn't an insurmountable obstacle; it's a timeframe and a cost that must be factored into the project from the outset.

The internal surface. In parts with channels, what cannot be reached remains as it came from the machine. A design decision must be made as to whether this is acceptable or if an internal finish needs to be provided.

Where to begin

The cheapest way to find out if a particular part fits is not to theorize: take the existing geometry and see what the cost and lead time would be. The quote calculator provides this with a breakdown of where every euro goes, and if the part isn't a candidate, it will also tell you. And to have it in hand before deciding anything, there are the open days.

The actual parts we have manufactured, by sector, are in parts.