Stimulaion And Study On Energy Recovery Strategy For Hydraulic Excavator Based On Virtual Prototype

Hydraulic excavators are the most widely used construction machine at present.Low overall efficiency,high fuel consumption and bad exhaust emission,However,are their critical disadvantages.Rapidly rising fuel prices,depletion of energy resources and increasingly stringent environmental concerns urge people to decrease energy consumption of hydraulic excavators and improve its overall efficiency considerably,yet still demonstrate competitive cost.In a broad sense, energy-saving technology includes energy recovery and recycling.The research and application of energy recovery and recycling for hydraulic excavators become the hot spot and trends at present and in the future.A typical 25 ton-class hydraulic excavator,equipped with double pump double hydraulic circuit and total power control system,has been chosen as the research object.First,subsystem models of the prime plant(diesel engine),mechanical mechanism of upper structure and hydraulic circuit have been constructed based Simulink^?,SimMechanics^TM,and SimHydraulics^TM in the environment of MATLAB/Simulink^? and multi-domain physical simulation and modeling platform—Simscape^TM,and the integrated virtual prototype(IVP) of hydraulic excavator has been realized with the relevant parameters of subsystems coupled by the power flow relationship based on power bond graph;Then the energy loss of main control valve—multi-way direction valve, which is widely used in hydraulic excavators,is analyzed.And a Simulink model is set up for calculating the energy loss of main valve.With no loads exerted on the bucket tip in a typical working cycle,simulation was carried out,the results indicate that about percent 13.31,percent 37.07 and percent 31.12 of the total effective output power of diesel engine was consumed on main valve,which mainly caused by meter-in,meter-out and bypass throttling.Therefore the most effective measurement for eliminating the throttling energy loss of main valve is to retrofit and optimize the hydraulic system.Using the experiencea of the state-of-the-art of the development, application and trends of the hydraulic hybrid drivetrain(HHD) technology developed by Eaton, etc.foreign companies,a novel hydraulic hybrid energy recovery and recycling strategy based on common pressure rail(CPR) with secondary control hydrostatic system,hydraulic transformer (HT) and hydraulic accumulator was introduced for recovery and recycling energy usually consumed on the main control valve system of traditional hydraulic excavator.At last,the Simulink models of diesel engine,hydraulic transformer have been created,and the integrated virtual prototype(IVP) of hydraulic hybrid excavator(HHE) was constructed.Simulation results show:comparing with original system,the diesel output power is constant at 90.3kW;fuel consumption reduced nearly 20.6%.It is evident that the hydraulic hybrid energy recovery and recycling strategy can improve the working conditions of diesel engine;dramatically decrease its fuel consumption.There is great potential of hydraulic hybrid drive(HHD) in the section of hydraulic excavator.