Heat exchangers from plastic garbage bags

HEAT exchangers for power plants can now be built using the same plastic for making garbage bags.

Joshua Pearce, an associate professor of materials science and engineering along with electrical and computing engineering at the Michigan Technological University, and his team have helped design and make plastic-based heat exchangers. The team, which was funded by the Advanced Research Projects Agency-Energy, built the exchangers layer by layer using a laser welder like in 3D printing and then puffed up the plastic to create a Michelin Man-like pattern.

According to Mr. Pearce, the key is expanded microchannel structures. The microchannels, which are brought about by the pattern, allow air or water to pass through. They also transfer heat from the exchanger’s hot side to the cold side.

Mr. Pearce noted that the temperature and pressure requirements for air-cooled condensers on power plants are modest, saying this allows the team to use polymer heat exchangers to improve efficiency and cut costs.

“This is really important as conventional power plants are finding it more and more difficult to compete with the recent price drops in renewable energy sources like solar. Now, our work is to try and take these small envelopes that we’ve made successfully and transfer them to a bigger scale,” he added.

“Even if one day all central power plants are replaced by more nimble distributed generation, heat exchangers may be in your house or your vehicle made out advanced garbage bags, which can increase the heat recovery and save you money at home,” Mr. Pearce further stated.