[home] [Personal Program] [Help]

---

Session: Poster session & Sponsor Exhibition
Session starts: Monday 07 October, 14:00

---

Wei Wang ()
Yu-Ting Wu ()
Chong-Fang Ma ()
Jing-Fu Wang ()
Guo-Dong Xia ()

Abstract:
Nowadays, the contradiction between continued growths in energy demand and gradually exhaustion of fossil energy become increasingly sharp, so energy saving has become the most urgent task. Among various waste energy resources, low temperature waste heat has a large proportion and no effective utilization, so people need develop distributed generation system (DGS) to recovery that energy. How to improve the performance of DGS is the key issue because of many technical bottlenecks. In this paper, different performance indexes of DGS based on Organic Rankine Cycle were analyzed by relevant thermodynamic principles. The thermodynamic model of Organic Rankine Cycle was described firstly, in which the thermodynamic performances of R134a, R245fa, R123, R600, R600a and R290 were compared, then the impact of expanders on ORC system was discussed, and finally potential improvement of ORC system using single screw expanders was evaluated. From the calculation results, it was found that there existed maximum net generation and highest thermal efficiency for certain heat sources and working fluids, and the optimized evaporation temperature in the former case was lower than that in the latter case. It was indicated that there existed different choices for difference types of heat sources. Ignoring the limitation of expanders, R245fa had the better thermal efficiency and the worse net generation than those of dry fluids R600a, for the same temperature difference between evaporation and condensation. However, for the same expansion ratio, both net generation and thermal efficiency of R245fa were worse compared with R600a. It was found that adiabatic efficiency would significantly influence the thermodynamic performance of power systems. For existent ORC experimental systems, as compared with refrigeration system, the corresponding indexes of efficiencies had a visible distance. However, it was also indicated that there is still huge room to improve.