Researchers from Tsinghua University and Brown University have discovered a simple way to give a major boost to turbulent heat exchange, a method of heat transport widely used in heating, ventilation and air conditioning (HVAC) systems.
Researchers from Tsinghua University and Brown University have discovered a simple way to give a major boost to turbulent heat exchange, a method of heat transport widely used in heating, ventilation and air conditioning (HVAC) systems.
In a paper published in Nature Communications, the researchers show that adding a readily available organic solvent to common water-based turbulent heat exchange systems can boost their capacity to move heat by 500%. That’s far better than other methods aimed at increasing heat transfer, the researchers say.
“Other methods for increasing heat flux — nanoparticle additives or other techniques — have achieved at best about 50% improvement,” said Varghese Mathai, a postdoctoral researcher at Brown and co-first author of the study, who worked with Chao Sun, a professor at Tsinghua who conceived of the idea. “What we achieve here is 10 times more improvement than other methods, which is really quite exciting.”
Turbulent heat exchangers are fairly simple devices that use the natural movements of liquid to move heat. They consist of a hot surface, a cold surface and tank of liquid in between. Near the hot surface, the liquid heats up, becomes less dense and forms warm plumes that rise toward the cold side. There, the liquid loses its heat, becomes denser and forms cold plumes that sink back down toward the hot side. The cycling of water serves to regulate the temperatures of each surface. This type of heat exchange is a staple of modern HVAC systems widely used in home heaters and air conditioning units, the researchers say. ow that the Best Practice Tariff drove changes in practice that reduced mortality for older adults with a hip fracture in England.
Read more at: Brown University
Turbulent heat exchangers use fluid dynamics to move heat. Plumes of warmer water rise from a hot bottom surface to a cold upper surface, where they lose their heat and sink back to the bottom. A new study shows that adding a small amount of a liquid additive to a water-based heat exchanger can speed the motion of the plumes and increase heat exchange capacity. (Photo Credit: Chao Sun)
