Woodruff School of Mechanical Engineering



Thermochemical Systems for Dehumidification, Air Conditioning, and Long-Distance Thermal Transport


Prof. Robert Wang


Arizona State University


Friday, November 5, 2021 at 11:00:00 AM   Add to Calendar


MRDC Building, Room 4211


Dr. Shannon Yee


Thermochemical heat stores thermal energy within chemical interactions as opposed to molecular vibrations and physical phase (i.e., sensible and latent heat respectively). This form of heat has historically been explored for high temperature, solar thermal power applications due to key advantages such as large energy densities and long-duration storage. In this talk, I instead explore concepts for mild and moderate temperature thermochemical systems and present corresponding thermodynamic analyses. I first present our concept for a liquid-phase thermochemical heat pipe. This system is analogous to the traditional heat pipe, but instead replaces endothermic boiling and exothermic condensation with endothermic and exothermic chemical reactions. Importantly, large portions of the heat within the thermochemical heat pipe can be stored indefinitely by incorporating chemical separation. This prevents thermal energy discharge into the ambient, facilitates long-distance thermal transport, and represents a step toward the potential creation of thermal energy grids. I next present our concept for Smart ThermOREsponsive (STORE) polymers as a fundamentally new type of desiccant for dehumidification and air conditioning. Like traditional desiccants, STORE polymers absorb gaseous water and thereby dehumidify. However, STORE polymers possess a fundamental difference when it comes to their regeneration process. Rather than desorbing water vapor into dry air at elevated regeneration temperatures (as done with traditional desiccants), STORE polymers instead desorb liquid water when they are heated above a critical phase transition temperature. This regeneration behavior allows for lower regeneration temperatures, higher coefficients of performance, and the ability to harvest liquid water for evaporative cooling


Robert Wang is an associate professor in mechanical engineering and also serves on the graduate faculty for chemical engineering and materials science at Arizona State University. He obtained his B.S. degree at the University of California, Los Angeles and his M.S. and Ph.D. degrees at the University of California, Berkeley. Afterwards, he studied as a postdoctoral fellow at the Molecular Foundry in Lawrence Berkeley National Laboratory. His research focuses on thermal management, thermal energy storage, thermal interface materials, thermochemical processes, thermoelectricity, colloidal nanocrystals, and nanocomposites. His work has been recognized by a Young Investigator Award from the Air Force Office of Scientific Research and a CAREER award from the National Science Foundation.