Solar-Powered/Fuel-Assisted Rankine-Cycle Power and Cooling-System: Simulation Method and Seasonal Performance

Abstract

The subject of this analysis is a solar cooling system based on a novel hybrid steam Rankine cycle. Steam is generated by the use of solar energy collected at about 100° C, and it is then superheated to about 600° C in a fossil-fuel-fired superheater. The addition of about 20–26 percent of fuel doubles the power cycle’s efficiency as compared to organic Rankine cycles operating at similar collector temperatures. A comprehensive computer program was developed to analyze the operation and performance of the entire power/cooling system. Transient simulation was performed on an hourly basis over a cooling season in two representative climatic regions (Washington, D.C. and Phoenix, Ariz.). One of the conclusions is that the seasonal system COP is 0.82 for the design configuration and that the use of water-cooled condensers and flat-plate collectors of higher efficiency increases this value to 1.35.