Effect of different external conditions on thermo-economic performances of the organic Rankine cycle

Affected by the fluctuations in external conditions, the organic Rankine cycle (ORC) deviates from the design condition, and the effect degree on thermodynamic and economic performance of the ORC is still unclear. Therefore, this study aims to investigate the variations of heat source temperature and mass flow, environmental temperature as well as the optimization on the effect degree of system’s thermo-economic performances. Firstly, the thermodynamic model based on the laws of thermodynamics and economic model based on module costing techniques are established. Then, effect degrees exerted of system and component performance by the variation in the heat source temperature and mass flow, environmental temperature are analyzed. Meanwhile, improvements of thermo-economic performance at the optimal condition are explored. Results show that the 𝑃𝐵𝑃 (payback period) and 𝐴𝑒𝑣𝑎 (evaporator area) are most affected by the variation of heat source temperature, the 𝑃𝐵𝑃 , as well as 𝑊𝑡 (turbine’s power output) and 𝑊𝑝 (pump’s power consumption) have the greatest changes with the variation of heat source mass flow, and the 𝜂𝑒𝑥 (exergy efficiency ) and 𝐴𝑐𝑜𝑛 (condenser area ) have the highest sensitivity to the variation of environmental temperature. In addition, the improvement of thermodynamic performance by the optimization behavior is almost greater than that of economic performance for ORC.