As a part of a computational and experimental research project funded by the DOE-Nuclear Energy University Programs (NEUPS), Post-doctoral Fellow Dorrin Jarrahbashi, and Graduate Students Sandeep Pidaparti and Taegyu Kang, all part of Dr. Devesh Ranjan’s group, won the Best Poster Award in the 5th Supercritical-CO2 Power Cycles Symposiumin in San Antonio, Texas. The group’s study focused on the condensating flow of supercritical carbon dioxide very close to the critical point in a venture nozzle and how this state mimics pressure drops in real cycles. Their research can be employed to indicate the optiumum design of compressor inlet conditions intended to prevent nucleation in supercritical carbon dioxide power cycles.

Power cycles for a variety of heat sources, including nuclear and solar energy, can benefit from supercritical carbon dioxide as a working fluid offering higher plant efficiency and a more compact footprint as compared to conventional steam cycles. Supercritical carbon dioxide power conversion technology offers a number of benefits over competing cycles such as size reduction of turbomachinery, increased efficiency, reduction of greenhouse gases, and reduced capital cost.

Designing optimal compressor inlet conditions in these cycles is critical. Possible pressure reductions may cause nucleation resulting in supercritical carbon dioxide turning into a two-phase mixture of condensate droplets and bubbles. These droplets have a serious impact on turbomachinery with respect to operation and the materials used in designing flow systems.