저온 폐열을 이용하기 위한 유기랭킨사이클의 작동유체 선정에 관한 연구

Abstract

Low-grade heats are wasted even though an amount of their energy is huge. In the small and medium industrialcomplex sites, large amount of low-grade thermal energy generated during the manufacturing process is wasted if it is not useddirectly for building heating or air-conditioning. In order to utilize this waste thermal energy more efficiently, organic Rankine cycle(ORC) was adopted. The range of operating temperature of ORC was set to 60℃ from 30℃ applicable low-temperature wasteheat. A study was conducted to select an appropriate organic working fluid based on these operating conditions. More than 60working fluids were screened. Eleven working fluids were selected based on the requirements as working fluid for ORC suchas environmentally friendly, safety, and good operation on the expander. Finally, six working fluids were selected by consideringthe operating temperature ranges. Then, a cycle analysis was conducted with these six working fluids. As a results, R-245fa andR-134a appeared as appropriate working fluids for ORC operating at low-temperature condition based on the system efficiencyand the turbine output power.