Abstract: Taking 300 t RH project for example, the hydraulic composition and pumpcontrol velocity regulation closed loop system were introduced. Focusing on energy conservation, loadsensing pump, accumulator energy recovery and independent control of actuator were designed. The energy conservation for different schemes were researched and analyzed. The project application result proved that 3.84×10⁷ kJ per year energy were saved and 39 % energy were reduced compared to common stable pressure pump system for continuous production, while energy conversation effect applying stable variable pump system was large for intermittent production. For the heat value and failure rate, loadsensing pump system in the second stage project greatly welcomed by the client were obviously reduced compared to stable variable pump system in the first stage project.

Key words: RH ladle lifting hydraulic system, hydraulic energy conservation, loadsensing pump, accumulator