A team at MIT has identified how the formation of droplets of water when condensation occurs could significantly increase the efficiency of all kinds of power and desalination plants. According to the team, the secret is in the size of the droplets.
In many cases on the condensing surfaces of smokestacks you see at many plants, droplets will grow larger and larger as moisture is released into the air. When gravity takes hold it will fall into a container down below. The scientists theorized that getting the droplets to fall earlier could make the plants more efficient.
The MIT team believes that by restructuring the interior surfaces of the smokestacks at the nanoscale it will cause the droplets to fall faster or even "jump" off the surface. This means the droplets will be smaller and the heat transfer is more efficient. This is critical to nuclear, natural gas or coal plants that operate by the heat source heating up water, steam turning a turbine, then rising into the condensation tower and then dropping again to begin the process all over again.
Greater efficiency in getting water droplets to fall could improve the rates of water production in desalinization plants or in solar power systems that rely on the efficiency of evaporative surface areas. In these cases it isn't just the droplets being smaller, it is the fact that they fall faster.
While studying how water droplets form on these structures is nothing new, the advances in micro and nanostructures has changed the way scientists are looking at how it might be accomplished. The next step is for the MIT team to further their modeling to see what works best and can be produced at a larger scale.
The results of the MIT work were published online in the journal ACS Nano a publication of the American Chemical Society. The team included mechanical engineering graduate student Nenad Milijkovic, postdoc Ryan Enright and associate professor Evelyn Wang.