Heat exchangers transfer thermal energy from one medium to another, and are used in both cooling and heating processes. As a result, they are used in a wide variety of applications and industries including energy, water, manufacturing, transportation, construction, electronic, chemical, petrochemical, agriculture and aerospace.
For decades, heat exchanger designs have remained relatively unchanged. However, say the researchers, recent advancements in 3D printing allow the production of three-dimensional exchanger designs previously thought impossible.
These new and innovative designs operate significantly more effectively and efficiently but require specific software tools and design methods to manufacture the high-performance devices.
"We developed shape optimization software to design a high-performance heat exchanger," says William King, professor of Mechanical Science and Engineering at The Grainger College of Engineering and co-study leader. "The software allows us to identity 3D designs that are significantly different and better than conventional designs."
The researchers started by studying a type of exchanger known as a "tube-in-tube" heat exchanger - commonly used in drinking water and building energy systems - where one tube is nested inside another tube. Using a combination of the shape optimization software using a genetic algorithm design and additive manufacturing, the researchers designed fins (only made possible using metal 3D printing) internal to the tubes.
The researchers demonstrated that their heat exchanger was able to achieve a power density of 26.6 W/cm 3 and specific power of 15.7 kW/kg.
"We designed, fabricated and tested an optimized tube-in-tube heat exchanger," says Nenad Miljkovic, associate professor of Mechanical Science and Engineering and co-study leader. "Our optimized heat exchanger has about 20 times higher volumetric power density than a current state-of-the-art commercial tube-in-tube device."
The optimized device is also said to perform well compared with shell-and-tube and brazed plate heat exchangers that are designed for significantly higher heat transfer. With billions of heat exchangers in use worldwide today, say the researchers, and even more attention placed on a need to