A quantitative study on the thermal performance of self-modified heat transfer surfaces in high heat flux flow systems
Year: 2023
Type: article
Abstract: The current work attempts to use a fundamental heat transfer experiment to understand the morphological and thermal performance effects of parametrically controlled nanoparticle deposition processes on heating surfaces. The first part of the work described here involves the use of nanosuspensions (Al2O3-H2O, 50nm, spherical particles) under forced convection and soft flow boiling. A relevant to fusion test bed has been used to perform the experiments. Nanoparticles are found to deteriorate the cooling performance of surfaces under such processes. A complex self-assembled porous nanoparticle layer is observed to form selectively on the heating surfaces. This negatively affects their thermal performance whether these are operated in pure or nanoparticulate latent coolants. Increasing the nanoparticle concentrations in the nanosuspensions reduced the negative thermal performance effects observed (up to the limits tested). As such, improvement of thermal performance beyond the break-even point witnessed for some conditions in the current work could be potentially achieved by increasing the concentration of nanoparticles in the coolant. When the nanosuspension is removed and the heat transfer surfaces with the nanolayer deposit are washed and operated with pure liquids, it was discovered that the layers survived and still affected (negatively) their heat transfer performance. The deposited layers are porous and are expected nevertheless to be beneficial to extending the critical heat flux of surfaces which is of industrial importance. Finally, it is expected that the deposition process and its final thermal properties could be affected by several controlled parameters providing numerous design opportunities for new or retrofitted applications that were otherwise inaccessible or unfeasible.
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,160
OpenAlex ID: W4385147765