Emergy analysis of Organic Rankine Cycle (ORC) for waste heat power generation

摘要

Converting the low grade energy into electric energy can effectively reduce the environmental pollution and improve the efficiency of energy utilization. Evaluating this kind of energy conversion is important. The sustainability evaluation of Organic Rankine Cycle (ORC) for the waste heat power generation is carried out using emergy analysis and life cycle method. The relationship to determine the transformity of the waste heat is presented. In the life cycle boundary, working fluid R134a in the ORC is firstly analyzed by emergy analysis. All the input flows including renewable resources, non-renewable resources and purchased investments in the whole life cycle of electricity produced by the ORC system have been calculated. The results show that the emergy yield ratio (EYR) and emergy index of sustain ability (ESI) of an ORC are 197.52 and 3.97, respectively. The sustainability of the ORC system is less than that of wind, hydro and geothermal power plant, but much greater than that of fossil fuel power plants. The emery proportion of the working fluid R134a accounts for 13.3% to the total input flows in the construction phase. The working fluid in an ORC system cannot be neglected in the life cycle analysis. (C) 2018 Elsevier Ltd. All rights reserved.