| Title | Performance Enhancement by Series Double Cascade-evaporation Organic Rankine Cycle (SDCORC) for Geothermal Power Generation |
|---|---|
| Authors | Tailu LI, Qiulin WANG, Jialing ZHU, Wencheng FU, Kaiyong HU |
| Year | 2015 |
| Conference | World Geothermal Congress |
| Keywords | ORC, SDORC, geothermal water, Double evaporator, Power generation |
| Abstract | The organic Rankine cycle (ORC) is a promising technology for heat recovery. The major problem is its low cycle efficiency, and the evaporator is a major contributor to the total irreversible losses. In this paper, the heat source is segmented in two temperature ranges to realize cascade evaporating. The series double cascade-evaporation organic Rankine cycle (SDCORC) was put forward. The objective of this paper is to evaluate the performance enhancement of the SDCORC with a reference to the ORC. The system performances (mass flow rate, evaporating temperature, volumetric flow rate (VFR), net power output, system efficiency, and thermal conductances) for the ORC and SDCORC were simulated and compared using R245fa as the working fluid. The objective function is the ratio of the net power output to the total thermal conductance, reflecting both the system earnings and the cost. The results show that the SDCORC can enhance the net power output, and the growth rate differs with intermediate geothermal water temperature (IGWT) and geothermal water inlet temperature (GWIT). The SDCORC exceeds the ORC and enhances the systematic performance with the GWIT. Optimal IGWT and evaporating temperatures of the SDCORC maximize the net power output. The SDCORC presents excellent systematic performance, which should be popularized in engineering applications. |