Implementation of PDORC (parallel double-evaporator organic Rankine cycle) to enhance power output in oilfield

The traditional ORC (organic Rankine cycle) based geoplant results in a higher irreversible loss. The PDORC (parallel double-evaporator organic Rankine cycle) was put forward to decrease the system irreversibility and enhance the power output. The TEIC (thermal efficiency intensification coefficient) was selected as the objective function. The PDORC was compared with the ORC through the energetic and exergetic analyses, with isopentane as the working fluid. The data of a practical geoplant was adopted to ensure the accuracy of the numerical calculations. The results show that the PDORC lowers the total irreversible loss, especially for the irreversibility caused by the evaporator, thereby enhancing the net power output. The TEIC relies on GWIT (geothermal water inlet temperature) and IGWT (intermediate geothermal water temperature), ranging from 8.11 to 15.84% for the GWIT between 80 and 150 °C. The optimal NPOI (net power output intensification) increases with the GWIT. The IGWT is a prerequisite, and there exists an optimal IGWT for each working condition. Moreover, the IGWT is function of the GWIT and CWIT (cooling water inlet temperature).