Research On Energy Recovery And Reuse Of Parallel Hydraulic Hybrid Loader

Loader is an important engineering machinery vehicle with characteristics of drastic changes of working load and serious energy waste.In this paper,the parallel hydraulic hybrid power system based on hydro mechanical loader is used to build the vehicle and control strategy model,and the simulation and bench test are carried out.The main research contents include:(1)The energy loss of loader and change of four characteristic parameters of vehicle speed,vehicle weight,shovel force and additional load of hydraulic system are analyzed.A parallel hydraulic hybrid loader system is proposed,the corresponding energy control valve group is designed,and the parameters of the key components of the hydraulic system are matched.(2)The V-cycle condition of loader is considered,and the engine working point and accumulator pressure state are taken as control parameters.A multi-objective and multi-mode energy recovery and reuse control strategy is proposed,which can realize braking energy recovery,potential energy recovery and active charging,and release hydraulic energy utilization under the working conditions of digging,starting acceleration,constant speed driving and lifting.(3)The whole vehicle and its control strategy model of parallel hydraulic hybrid loader are built.Under the V-cycle condition,the influence of the initial pressure of the accumulator is analyzed,and the optimal value of the initial pressure of the accumulator and the minimum threshold value of the accumulator pressure are determined.Compared with the hydraulic mechanical loader,the economy and engine working point of the parallel hydraulic hybrid loader are improved,and the energy balance of the accumulator is guaranteed.(4)The simulation results of the logic threshold are optimized,based on genetic algorithm.The simulation results show that the economy of loader is further improved while the energy balance of accumulator is guaranteed.The parallel hydraulic hybrid loader simulation test bench and control acquisition system are built.Combined with the evaluation model of energy recovery and reuse rate and bench test results,the influencing factors of energy recovery and reuse rate are analyzed.