Exergetic and exergoeconomic implications of a recuperative organic Rankine cycle plant for power production from an abandoned oil well

This study was aimed at assessing the exergetic and exergoeconomic implications of adopting a recuperative (SUB-REGEN) instead of a non-recuperative (SUB) organic Rankine cycle (ORC) plant for power production from an abandoned oil well. The geometric parameters of a typical oil well in Nigeria were adopted for simulating the heat source. The specific exergy costing (SPECO) approach was employed for the exergoeconomic assessment. Results showed that for the SUB ORC, the evaporator had the highest exergetic efficiency of about 86% and the condenser the highest cost rate of exergy destruction of about 47%. For the SUB-REGEN ORC, the condenser had the highest contribution ratio of 0.41 to the total irreversibility with a cost rate of about 19.1 k$/h. Overall, the integration of a recuperator would increase the ORC exergetic efficiency from around 55% to 58%, albeit with a consequent increase in the cost rate of system irreversibility by about 24%.