下偏杠铃复合平衡游梁式抽油机的节能效果分析

应用波动方程描述抽油杆柱的振动，建立了抽油机悬点动力示功图的仿真方法；考虑了地面各机构传动效率对复合平衡游梁式抽油机各节点功率的影响，建立了地面各单元分效率与电动机实耗功率的仿真方法。仿真结果表明，与单独的曲柄平衡游梁式抽油机相比，复合平衡游梁式抽油机的节电率随游梁平衡重质量的增加而增加，其节电的根本原因是四杆机构的平均运行效率随游梁平衡重质量的增加而增加，与传统的复合平衡游梁式抽油机相比，游梁平衡重下偏对地面各单元的分效率与节电率影响甚小。由于复合平衡游梁式抽油机（包括下偏杠铃复合平衡游梁式抽油机）不能明显减小曲柄轴扭矩波动，因此复合平衡游梁式抽油机不具有降低装机功率的特点，因此，下偏杆铃复合平衡游梁式抽油机的节电效果与传统的复合平衡游梁式抽油机基本相同。

Research on the saving energy effect of a compound balance beam pumping unit of beam balance weight deviated downward

The vibration of the rod string is described by the wave equation,and the simulating method of the dynamic cards of the polished rod of a beam pumping unit is set up.The affecting of driving efficiency of various mechanisms on the power of various joints of a compound balance beam pumping unit is considered,and the simulating method of various unit efficiencies and the consumed power by the motor is set up.It is pointed out that the saving energy ratio of a compound balance beam pumping unit which is compared with a crank balance beam pumping unit is getting higher when the weight of the beam balance weight is getting heavier.The reason of saving energy of a compound balance beam pumping unit is that the average running efficiency of the four bar linkage mechanism is getting higher with the raising of the weight of a beam balancing weight.The various unit efficiencies and saving energy ratio of a compound balance beam pumping unit is affected little when the beam balance weight is deviated downward.Because the varying extent of the net torque of the crankshaft of a compound balance beam pumping unit can not be reduced greatly,a compound balance beam pumping unit is not of the advantage of reducing the rated power of the motor. Therefore the result of saving energy of a compound balance beam pumping unit of which beam balance weight is deviated downward is similar to a general one.