Director of Office of Professional Programs; Professor of Mechanical Engineering; Affiliate of the Environmental and Ecological Engineering
M.S., Ruhr-University of Bochum, 1989
B.S., Ruhr-University of Bochum, 1986
A recent project of Prof. Groll’s is entitled the “Liquid Flooded Ericsson Cycle Cooler” (with collaborators Ian Bell, James E. Braun, and Galen B. King). For the last century of air conditioning and refrigeration, vapor compression has dominated the cycle technologies employed. The Flooded Ericsson cycle under investigation is an alternative cycle technology that can provide cooling capacity. This cycle is essentially a gas refrigeration cycle, but with the addition of relatively large liquid flows to the compressor and expander gas streams to achieve nearly isothermal compression and expansion. The cycle is flexible with respect to the gas and liquid used, and can be charged with many different gases with near-zero GWP and zero ODP for environmentally-friendly operation. The two system components that have the greatest impact on overall system irreversibilities and system efficiency are the compressor and expander, and one of the major thrusts of the current research is to design compressors and expanders that are more suited to the application of two-phase compression and expansion. The simulation models that will be developed to predict the performance of the cycle and the compression and expansion processes will be validated through the use of a Flooded Ericsson Cycle Cooler test stand as well as a stand-alone compressor/expander test stand.