Improving heat transfer in industrial plants

According to the MIT team, understanding the properties that control surface dissipation of heat could lead to improved power plants and electronics with high heat-transfer rates.

The research involves a key transition point known as the critical heat flux, or CHF. This is a value of heat transfer, per unit time and area, where a surface’s heat-transfer characteristics suddenly change.

The research could lead to safer nuclear reactors

An example is when the cooling panels of an electronics system become covered with a layer of vapour that blocks heat transfer. The resulting rise in temperature can damage or destroy the equipment.

Until now, there has been no agreement on the relative importance of three surface attributes that could affect the onset of CHF: roughness, wettability (the ability of water to spread across a surface) and porosity.

Now, after a detailed investigation, the team has found that the presence of a porous layer on a material’s surface is by far the most important factor.

The new findings could raise the value of CHF, providing extra safety margins or operating ranges for such equipment.

MIT’s Jacopo Buongiorno, an associate professor of nuclear science and engineering, claims the research could lead to safer nuclear reactors, more efficient heat exchangers, and better thermal management of high-power electronics.