柔性抽油机节能原理探讨

柔性抽油机结构上使用钢丝绳和滑轮组替代了常规抽油机的游梁和连杆。以X2-D4—641井为例验证其节能效果表明，与常规抽油机相比，其节电率高达44.87％。分析认为，影响抽油机系统效率的主要因素是悬点载荷。悬点载荷波动小，则抽油机运行平稳，有利于降低装机功率，提高电机效率。据此，对滑轮组中钢丝绳长度与曲柄旋转角之间的函数求导，得出悬点加速度的函数；函数曲线显示，柔性抽油机最大加速度为0．1m/s^2左右，远小于常规抽油机的0．5～1．0m/s^2，说明柔性抽油机悬点载荷远小于常规抽油机；示功图对比显示，柔性抽油机所受载荷的波动幅度减小．抽油机运行状况平稳；抽油机装机功率从37kw降到18．5kW，消耗功率从13．55kW降到7．81kW，提高了电机负载率，即提高了电机效率，从而达到节能的目的。但仍存在摩擦力增大，钢丝绳和滑轮组的使用寿命降低等缺陷。

Discussion on the Energy-saving Principle of the Flexible Pumping Units

Wire rope and assembly pulley on the flexible pumping units replace balance beam and connecting rod on regular pumping units.The energy-saving effect of the flexible pumping units was proved in well X2-D4-641 with electricity-saving ratio high up to 44.87%.The main factor of influencing system efficiency of the pumping units was polished rod load.Small change of the polished rod load brings stable operation of the pumping units,which was favorable to make installed power lower and electrical machinery efficiency higher.The derivation of the function between the length of the wire rope and rotation angle of the crank was solved,and the function of suspension center acceleration was established.The function plot shows that maximum acceleration of the flexible pumping units is about 0.1m/s^2,which is much less than the value of the regular pumping units 0.5 to 1.0m/s^2.So the polished rod load of the flexible pumping units is much less than that of the regular pumping units.Indicator diagram presents that amplitude of fluctuation of the load for the flexible pumping units decreased with stable operation ;the installed power decreased from 37kW to 18.5kW,and consumed power decreased from 13.55kW to 7.81kW.Charging ratio of the electrical machinery was improved,that is to say,the efficiency of it was improved and energy was saved.It still has the shortcomings：if the friction increases ,service life of the wire rope and assembly pulley is shorter.