가변 열원에서 작동하기 위한 유기랭킨 사이클에 관한 연구

Abstract

An organic Rankine cycle was analyzed to work at the optimal operating point when the heat source is fluctuated. R245fawas adopted as a working fluid, and an axial-type turbine as expander on the cycle was designed to convert the heat energyto the electricity since the turbo-type expander works at off-design points better than the positive displacement-type expander. A supersonic nozzle was designed to increase the spouting velocity because a higher spouting velocity can produce more outputpower. They were designed by the method of characteristics for the operating fluid of R245fa. Three different cases, such asvarious spouting velocities, various inlet total temperatures, and various nozzle numbers, were studied. From these results, anoptimal operating cycle can be designed with the organic Rankine cycle when the available heat source as renewable energyis low-grade temperature and fluctuated.