Experimental study of the organic rankine cycle under different heat and cooling conditions

A small-scaled organic Rankine cycle (ORC) system using R123 as working fluid was experimentally investigated. For ORC and regenerative organic Rankine cycle (RORC), the impacts of the evaporating and condensing temperatures on the performances of main components (i.e., the expander, the pump, and heat exchangers) and the system were tested. The comparison between these two systems under identical working conditions was also carried out. The results showed that the expander shaft power of ORC is greater than that of RORC under the identical evaporating temperature and condensing temperature. When the evaporating temperature is relatively low, the expander shaft power is more sensitive to the condensing temperature, and the thermal efficiency of ORC is higher than that of RORC. With the increasing of the evaporating temperature, the thermal efficiency of RORC exceeded that of ORC. Therefore, ORC is recommended for the low temperature heat source, while for the high temperature heat source, RORC is recommended for its higher thermal efficiency.