Xergy, University of Delaware Researchers Work to Build a Better Heat Pump
Use of fuel cell technology provides new approach
SEAFORD, Del. — Xergy Inc., a high-tech startup, has announced a new refrigeration system based on an electrochemical compressor to replace the conventional mechanical vapor compression systems found in typical heat pumps. The company credits the University of Delaware’s Ajay Prasad and his research team with playing an important role in the breakthrough.
“When Xergy approached us to collaborate on this idea, we recognized that electrochemical compressors [ECCs] are very similar to fuel cells,” said Prasad, who directs the University of Delaware’s Center for Fuel Cell Research. “For example, ECCs employ many of the same components, including an ion-exchange membrane, gas diffusion layers, bipolar plates, and catalysts.”
However, there are some key differences that pose challenges in transitioning this technology to HVAC applications.
Graduate student Ashish Chouhan, who is working with Prasad to address these challenges, explained that traditional ion-exchange membranes must be highly hydrated in order to permit proton conduction. However, Xergy’s design, which employs metal hydride heat exchangers, must be moisture free, as water can seriously degrade the metal hydride beds.
“We are testing various membrane and catalyst layer formulations that will pump hydrogen effectively in the complete absence of water,” Chouhan said. “We have tested several ion-exchange membranes and are now focused on membranes made from a high-performance polymer called polybenzimidazole for this task.”
Initial applications for the technology include hybrid water heaters and air conditioners. ECCs offer the advantage of being extremely efficient and quiet because they have no moving parts, plus they allow the use of environmentally friendly refrigerants.
“It’s no longer a matter of if, but when, this technology will enter the market,” said Xergy president Bamdad Bahar in announcing the breakthrough.
“We’ve proven that refrigeration systems based on electrochemical compression are a viable alternative. Now it’s just a matter of refinement to get the package smaller and cheaper so that it can see widespread adoption in a wide variety of appliances for global markets.”
Once the technology has been refined, Xergy plans to expand ECC applications to include residential and commercial air conditioners, refrigeration systems, and other heating and cooling applications.
“This technology has the potential to transform refrigeration systems worldwide and bring about significant environmental benefits,” said Prasad. “Improvements in HVAC system efficiencies will greatly reduce the electricity demand from power plants leading to reductions in greenhouse gas emissions.”
“In addition, widespread adoption of ECCs will bypass the 150 million electric motors that are required to drive mechanical compressors, which will reduce our dependence on critical raw materials that go into electric motors.”
The research was funded through the U.S. Department of Energy.
For more information, visit www.xergyinc.com.
Publication date: 4/13/2016