Design of an Energy Regeneration System for Pressure Reducing Stations of Crude Oil Pipeline

In this study, the possibility of energy recovery from oil pipelines as a source of clean energy is discussed. At present, a significant amount of energy is lost in oil pressure reducing stations. The energy regeneration scheme proposed in this study investigates the possibility of converting the currently wasted energy into the electrical energy by using a Francis turbine coupled with a synchronous generator system. The dynamic hydraulic model of the existing pipeline system starting from the compressor stations to the pressure regulating stations is obtained. Also the state space equations of the energy regeneration system including the control valves, the turbine and the synchronous generator connected to a local load are modeled. The propositional-integral-derivative (PID) and linear quadratic regulator (LQR) are designed to control the flow, pressure, speed and voltage in the energy regeneration system. The results of two controllers are then compared under different conditions. The obtained model for Razan-Shazand transmission line crude oil are simulated and the results are interpreted. The results show the possibility of a significant energy regeneration and the appropriate performance of the designed system with the proposed controllers.