Understanding Applications Possible Today
Every additive manufacturing application investigated should have a good business case behind it. In the context of heat exchangers, an AM design can address multiple aspects of the business case through weight savings, performance gains, reliability & maintainability, and more.
Many different types of heat exchangers exist, so which one(s) should you focus on? Not all heat exchangers are created equal. All heat exchanger classifications and flow arrangement types have their place.
Several factors go into choosing the “right” heat exchanger:
- Fluid type/properties
- Operating temperatures and pressures
- Environment
- Cost
- External System (pumps, etc.)
- Weight Requirements
- Allowable design space
- Manufacturing constraints
The current limitations of AM constrict the minimum feature size (i.e., wall thickness) and the maximum build volume within printers. The minimum feature size limitation has been a primary driver in the applications nTop is working on with our clients today. We’ve discovered that currently, liquid-to-liquid type heat exchangers have the most promise due to the higher pressures typically seen in these systems. In contrast, gas-to-gas applications have shown to be less effective due to the exceptionally thin walls that traditional manufacturing techniques can produce. The minimum wall thickness we’ve successfully printed to and burst pressure tested is around .45mm, where the burst pressure requirement of the AM heat exchanger exceeded the operating margin by more than 12x. That being said, many companies have developed their own processes for qualifying minimum feature sizes below 0.2mm for certain types of metal powders.
As AM technology continues to see improvements in lasers and optics technology, minimum feature sizes will improve, opening up better avenues for broader HEX applications.