Scientists developed a new technique that could prevent accidents at nuclear power plants, according to a study published on November 14, 2018.
This study was conducted by the scientists at the University of Hawaii at Manoa. Boiling is used an effective cooling mechanism in many industrial applications that are associated with hot components. This is due to latent heat, the heat absorbed to change water into vapor, which removes a huge amount of heat from a hot surface. However, there is a limit to the amount of heat that can be eliminated through boiling.
As a solution to this problem, Sangwoo Shin, an assistant professor in mechanical engineering at the UH Manoa College of Engineering developed a novel concept that is capable of overcoming the tolerable heat limit. This tolerable heat limit is known as critical heat flux (CHF). Through this research, the scientists were able to increase the CHF by 10 percent when compared to the approaches that were used in the past. Shin says that this is a very necessary method because if the surface is extremely hot, the water near the surface will quickly change into vapor. Then, there will be no liquid left to cool the surface.
Until now, use of nanostructures to roughen the surface was the method used to enhance the CHF. High surface roughness leads to an increased number of sites at which the bubbling occurs, thus resulting in enhanced CHF. Shin says future studies to further CHF enhancement can be expected by choosing the right geometry and material for the nano-bimorphs, which may contribute to developing energy-efficient technologies for extremely hot systems.