起重机变幅系统能量回收利用系统的特性研究

Research on the Characteristics of Energy Recovery and Reuse System for Crane Luffing System

针对汽车起重机变幅机构下降时平衡阀的流量稳定性较差且系统能耗大的问题,在起重机泵阀协同压力流量复合控制液压系统的基础上,提出一种汽车起重机变幅系统能量回收利用系统。利用蓄能器不断增加平衡阀背压,使平衡阀前后压差稳定,实现压力补偿,使变幅机构下降速度更加平稳,同时回收变幅机构下降时释放的重力势能,并在起升负载时将蓄能器接在泵进口处实现能量再利用。利用AMESim和Simulink软件对系统进行联合仿真,通过仿真结果对能量回收利用系统的平衡阀进行流量特性分析,并与泵阀协同压力流量复合控制液压系统进行能效对比。结果表明:当变幅机构下降时,汽车起重机变幅系统能量回收利用系统的蓄能器压力变化与负载压力变化趋势大致相同,平衡阀前后压差更加稳定,流量控制稳定性提高;在相同流量时,平衡阀阀口开度变大,并在实现过补偿功能时,平衡阀主阀口开度关小率降低,从而节流损失减少;在起升负载时,泵进出口压差减小,从而降低原动机的输出扭矩。起重机变幅系统能量回收利用系统的能量回收率为17.6%,能量再利用率为86.6%,此系统的能量回收利用率为15.2%,达到了能量回收利用的目的。

In response to the problem of poor flow stability and high system energy consumption of the balance valve with the descend of crane luffing mechanism,an energy recovery and utilization system for the crane luffing system was proposed based on the hydraulic system of pressure flow composite control in collaboration with the pump valve of the crane.An accumulator was utilized to continuously increase the back pressure of the balance valve,stabilizing the pressure difference between the front and rear of the balance valve,achieving pressure compensation to make the lowering speed of the luffing mechanism more stable.At the same time,the released gravitational potential energy was recovered during the lowering of the luffing mechanism,and the accumulator was connected to the pump inlet during load lifting to achieve energy reuse.Joint simulation of the system was conducted using AMESim and Simulink software.The flow characteristics of the balance valve of the energy recovery and utilization system was analyzed through simulation results,and the energy efficiency was compared with the pressure flow composite control hydraulic system in collaboration with the pump valve.The results show that when the luffing mechanism descends,the pressure change of the accumulator in the energy recovery and utilization system of the truck crane luffing system is roughly same as the change trend of the load pressure,the pressure difference between the front and rear balance valve is more stable,and the stability of flow control is improved;at the same flow rate,the opening of the balance valve port increases,and when the overcompensation function is achieved,the closing rate of the main valve port of the balance valve decreases,thereby reducing throttling loss;when lifting the load,the pressure difference between the inlet and outlet of the pump decreases,thereby reducing the output torque of the prime mover.The energy recovery and utilization rate of the crane luffing system is 17.6%,and the energy reuse rate is 86.6%,the energy recovery and utilization rate of this system is 15.2%,achieving the purpose of energy recovery and utilization.