Experimental and theoretical study on a novel energy-saving ECS for commercial airliners

With the advancement of the design requirements for more electric airliners, subsystems such as the environmental control system (ECS) are transforming from the traditional bleed engine driven style to the electrically driven type. Aiming at the electrically-driven ECS of the Boeing 787 dream airliner, in this study, a novel energy-saving scheme for recovering power from the cabin-discharged air and convert it into shaft work to pre-pressurize fresh air is proposed. The thermodynamic parameters are analyzed by using the enthalpy method. Compared with the B787 scheme, the proposed method can save 66.2% of the input power and increase the coefficient of performance (COP) from 0.309 to 0.915. We use the take-off gross weight method to evaluate the effects of the two schemes on the aircraft fuel penalty loss. The results show that the penalty loss difference between the power recovery and thrust recovery is less than 15 kg, and thus the overall impact on the aircraft can be ignored. A test platform using a turbocharger on an automobile is built to test the performance of the power-recovery unit under different simulated flight altitudes. The experimental results show that the turbocharger can recover shaft power in the range of 2.2–10.1 kW and that power is easily recovered via the novel energy-saving scheme.