| As a multi-purpose construction machinery,wheel loader plays a huge role in the field of engineering construction.Hydraulic system is an important part of the loader to achieve the operation function,its efficiency and reliability directly affect the loader's energy consumption and machine performance.This paper analyzes the dynamic characteristics and energy consumption of the quantitative hydraulic system of the 50 loader.The hydraulic system includes the problems of high energy consumption,low efficiency and high heat balance temperature.Therefore,we analyze the energy saving technology of hydraulic system of loaders,analyze and improve the heat dissipation characteristics of the system.Firstly,build the joint simulation model of loader hydraulic system.The dynamic model of the working device was established in ADAMS,the hydraulic system model was established in AMEsim,and the real-time interaction of the data was realized by the interface file.The simulation results were compared with the experimental values to prove the correctness of the model.It was found that the energy consumption of the quantitative hydraulic system was large by analyzing the power consumption of each component for a working cycle hydraulic system under type I operating conditions,and there was overflow loss and median unloading loss.The efficiency of the hydraulic system was low,the excess energy converted to heat which caused the system temperature increases,and the whole machine operating efficiency was reduced.Secondly,studied the hydraulic system energy saving technology due to the low efficiency of the hydraulic system: use a load-sensitive hydraulic system to reduce the power output and overflow losses of the hydraulic pump;study the boom potential energy recovery technology to reduce the throttle loss of multiple valves when the boom is lowered;study the effect of improving the system pressure on system efficiency.Then the dynamic characteristics,energy consumption and efficiency of the above different systems were analyzed.Thirdly,this paper established the heat exchange model of loader hydraulic system.Analyzed the heat production mechanism and heat dissipation characteristics of thehydraulic system,studied the proportion of each component in the heat or heat dissipation phase,studied the effect of ambient temperature on the thermal equilibrium and paved the way for system improvements.The effect of the system temperature was analyzed by using the following methods: the load-sensitive hydraulic systems;boom potential energy recovery systems;temperature bypass valves;changes the flow through radiator,etc.Finally,the loader hydraulic system characteristics test and thermal balance test were carried out,two typical conditions of type I operation and high speed running were analyzed,and measured the pressure and temperature changes in various parts of the system which provided initial boundary conditions for simulation.The correctness of the established hydraulic system model and heat exchange model was proved by the above experiment. |
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