Coating technology promises to increase energy efficiency at power plants
Beta Boston, September 28, 2015. Image credit: www.gipom.com
DropWise, the brainchild of two Massachusetts Institute of Technology professors, Kripa Varanasi and Karen Gleason, and two of their students, is a coating technology for heat exchangers in power plants and chemical refineries.
In a power plant, fuel is burned to heat a boiler full of water to create steam, which flows through a turbine. The steam spins the turbine and creates electricity. To limit the amount of water used, the steam is then recycled and recirculated into water via a heat exchanger.
The steam from the turbine flows into the heat exchanger and surrounds metal tubes with cold water flowing inside. The DropWise technology coats the outside of the cold-water tubes, reducing the film that builds up around the tube when the steam condenses into water, allowing more efficient cooling.
The DropWise coating, 2,000 times thinner than a piece of paper, has the potential to offset the same amount of carbon emissions as taking several thousand cars off the road by increasing efficiency, said Adam Paxson, DropWise president and chief executive.
Paxson said if all steam condensers have a water-repellent coating, it would cut more emissions than the entire global solar and wind industries. Annica Blake, chief operator for DropWise, said the coating”can save an average 500MW power plant hundreds of thousands of dollars per year.”