Brandon White, Engineer, Experimental Research
Additive manufacturing has matured to the point where complex, performance critical geometries can be produced quickly and cost effectively. At HTRI's Research & Technology Center (RTC), we have integrated a PhotoCentric® Liquid Crystal® Magna 3D printer into our development workflow. This system allows us to fabricate complete shell-and-tube heat exchanger assemblies with tube bundles that employ Xist® tube dimensions and layouts.
Our recent efforts focus on printing the shell-and the-tube bundle, refining process parameters to achieve the tight tolerances required for reliable thermal hydraulic testing. Key challenges include characterizing the printed material's thermal conductivity, specific heat, and mechanical strength, as well as establishing safe operating limits.
Figure 1 shows a shell (left) and a tube bundle (right) still attached to the printer's build plate. The resin utilized for printing cures (solidifies) when subjected to ultraviolet (UV) radiation. The red light does not produce UV radiation and prevents the resin from curing while sitting in the printer vat.
Figure 2 shows a 3D-printed TEMA X-shell tube bundle that is being used for seal strip analysis.
Producing prototype exchangers in house lets HTRI evaluate novel configurations on a small scale before committing to full size hardware, accelerating innovation while reducing capital expense. Ongoing work will expand the library of printable geometries, integrate advanced lattice structures for enhanced heat transfer, and validate the long term performance of additively manufactured components.