Analysis of a novel energy-efficient system with 3-D vertical structure for hydraulic press

Abstract A hydraulic press is a closed energy-conversion system comprising electric energy, mechanical energy, hydraulic energy, and deformation energy. In this system, the energy losses among multiple energy-conversion processes are significant, particularly in the hydraulic energy conversion, resulting in low energy efficiency. To address this issue, this study proposes a three-dimensional vertical arrangement for a hydraulic press that reduces energy dissipation and improves the energy efficiency of the system. In this structure, the space above and below the ground is used comprehensively and the hydraulic equipment are arranged sequentially in vertical layers. Some equipment are connected directly to minimize the use of valves and pipelines; this reduces the transmission distance of hydraulic energy between the pump station and the actuator, as well as the number of control valves. Furthermore, an energy-saving buffering device was installed at the top layer of the structure to absorb pressure fluctuations and reduce structural oscillations. As a case study, the proposed structure was applied to a 35-MN hydraulic press. The results of theoretical calculations, simulations, and comparative experiments indicate that, when using the proposed system, the energy efficiency of the press could be improved by 20.0% and the average energy consumption of the pipeline-valve system could be reduced by 65%.