Abstract:
To reduce energy consumption and carbon emissions of medium-sized hydraulic excavators, a hydraulic-electric hybrid power system and a hydraulic-hybrid power system, both with energy recovery equipment, were devised in combination with the current energy-saving method after the energy-consumption characteristics of the traditional hydraulic excavator system were analyzed. According to the parameter configuration of the 23 t hydraulic excavator from a company, three kinds of mathematic models of slewing mechanism were set up, i.e., the traditional hydraulic excavator system, the hydraulic-electric hybrid system, and the hydraulic hybrid system. The AMEsim software was used to calculate the models in the condition of the same load, and the characteristic curves of the angular displacement, angular speed, power and energy-consumption were analyzed. The results indicate that in terms of the dynamic response of angular displacement and speed, the two hybrid slewing systems are more rapid and accurate than the traditional hydraulic system, and the hydraulic-electric hybrid system is faster than the hydraulic hybrid system. Compared with the traditional hydraulic power system, the hydraulic-electric and hydraulic hybrid power systems obtain an energy-saving index of 42% and 28%, respectively.