Year: 2004
Type: conference-paper
Abstract: Renewed interest in waste heat power recovery has resulted in the development of Organic Rankine Cycle (ORC) products with the recently commercialized refrigerant R-245fa [1,2,3].A thermodynamic cycle analysis program predicting the performance of ORC systems has been written in support of the development of these products.This cycle program allows the use of different organic working fluids and various sources of waste heat.It also accounts for actual turbine and pump efficiencies, refrigerant line pressure losses and finite boiler and condenser surface area.Using this cycle program, the relative thermodynamic efficiency of various potential working fluids is determined for three waste heat power recovery applications: gas engine exhaust, landfill flare gas and condensing steam.The analysis is carried out for both recuperated and non-recuperated ORC cycle configurations and includes watercooled as well as air-cooled condenser options.The differences in ORC thermodynamic cycle efficiency of various refrigerants were found to be substantially larger than the differences in thermodynamic efficiency of these same fluids for vapor compression cycle applications.Second law analysis of the results explains these findings.ORC thermodynamic efficiency correlates well with the critical temperature of the working fluid.Future ORC systems could benefit from the development of safe and environmentally acceptable working fluids with higher critical temperatures than currently available.
Authors: Lars J. Brasz, William M. Bilbow
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1504961988