Dr. Bao Yang, Professor, University of Maryland, College Park, USA.

Speech Title: Development of Novel Microemulsion Absorption Cooling Systems

Abstract: A large number of absorbents and adsorbents have been investigated since the first sorption chillers were developed more than 150 years ago. Sorbents can be classified as either absorbents or adsorbents, and some commonly used absorbent/refrigerant pairs are LiBr/H2O and H2O/NH3. Commercial adsorption systems typically utilize zeolite/water and silica/water, where water is the cycle refrigerant. In all previously-known sorbents, the refrigerant is released in gas phase, resulting from a phase transition from condensed phase (liquid or solid) to gas. Therefore, the heat of desorption is always larger than their heat of vaporization, making evaporative desorption a fundamental difficulty that limits the energy conversion efficiency of sorption chillers. In this talk, the potential application of new class of sorption materials , microemulsion absorbents in thermal-driven absorption chiller will be discussed. The proposed absorption cooling system utilizes a novel oil-based microemulsion liquid absorbent, recently invented by the researchers at the University of Maryland. These microemulsion absorbents can absorb water vapor (refrigerant), and release the water as liquid without vaporization or boiling, when heat is supplied. The proposed microemulsion cooling system is capable of providing supplemental cooling required to lower the exit water temperature from an air-cooled heat exchanger to below the dry-bulb temperature, while being driven by waste heat from a power plant.