The Massachusetts Institute of Technology’s physicists have developed a method that speeds up boiling water and lowers energy costs. The principle is based on a specific surface structure of the heating element.
An electric kettle is equipped with a heating disc or coil. When the water is heated, steam bubbles form at the bottom. Their number will increase as the temperature increases. If they are too close together, they can form a gas layer that reduces heat transfer from the heating element to liquid.
Evelyn Wong and her colleagues came up with a solution. The heating element has been redesigned so that bubbles grow larger but don’t merge. This prevents the formation of gas layers.
A set of recesses measuring 10 micrometers in width is included with the new heating element. These recesses are located on the heating element at a distance of approximately 2 mm between each other, and are placed on small elevations. These elevations direct heated water from the bottom to the recesses. This creates a flow of liquid which increases heating efficiency.
This is how the heating element’s surface looks.
Experiments show that the heat transfer coefficient for the new element is nearly 4x higher than the one used in the past, while the critical heat flux (an important indicator of gas formation during heating) has almost 1.5x.
This will result in significant energy savings for a nu
