Robert Barber’s scientific contributions

The development of a demonstration package supplying residential cooling and/or electricity via a solar-heated Rankine Cycle is discussed. The 3-ton air conditioning, 1-kW electric system employs a solar collector to warm flowing water which provides input heat to a low temperature organic (R-113) Rankine Cycle. Expansion through a high speed (∼50,000 rpm) turbine-speed reducer drives an available R-12 refrigeration compressor and 3600 rpm motor-generator.The design point solar collector water temperature is 215°F, providing an R-113 temperature at the turbine inlet of 200°F. With a water-cooled R-113 condenser purveying a condensing temperature of 95°F and a turbine efficiency design goal of 80%, Rankine Cycle efficiency (turbine shaft power divided by heat input to the working fluid) is 11·5%.An 85% efficient R-12 compressor yields an overall coefficient of performance (COP) goal of 0·71.The project is jointly funded by Honeywell, Inc., and the National Science Foundation.