Analysis of a novel energy-efficient system with a bidirectional supercharger for forging hydraulic press

Abstract

The mismatch between the installed power and required power is the main cause of the high energy dissipation and low energy efficiency of hydraulic presses. Based on the operating principle of a high-pressure water jet, this study proposes a novel energy-saving method to solve this mismatch. In the proposed method, an energy-efficient supercharging system composed of a bidirectional supercharger, recovery accumulator, and special control system was integrated into a hydraulic system for the first time. The pressure and kinetic energy of the hydraulic oil from the supercharging system were significantly higher than those of the conventional power units. Subsequently, the supercharging system was used to energize the hydraulic press together with the conventional drive units, thereby realizing high-power load operation with low installed power. A configuration and control strategy for the supercharging system were constructed. Based on this configuration, a recovery accumulator was adopted to store the hydraulic energy as well as pressure and flow pulsations generated by the supercharger at the low-load and no-load stages. Moreover, a servo supercharging system was proposed to realize a high-precision power supply according to the load profiles at the high-load stage. Finally, the proposed system was applied to a 32 MN forging press as a case study. The results indicated that the energy dissipation and installed power were reduced by 48% and 20%, respectively.