游梁式抽油机变速运行模式优化

Optimization of variable speed operation mode for beam-pumping units

为解决常规游梁式抽油机在正常运行时存在平衡状况差、系统能耗大等问题,开展了变速驱动技术研究。通过控制电动机转速调节系统的运行状况,降低系统能耗;基于平衡功率调速,重载慢驱、轻载快驱的理念,建立了抽油机变速运行运动学模型和动力学模型;利用非线性耦合方法对系统仿真模型求解。研究发现,所有电动机变速曲线基本都遵循马鞍形曲线的变速规律,并以电动机输出瞬时功率最低为优化目标,对变速运行模式进行优化。结果表明,优化变速曲线相比原始变速曲线,曲柄旋转角速度峰值降低了3.5%,但悬点速度峰值降低了28.6%,曲柄瞬时功率峰值降低了24.96%,证实优化变速曲线节能效果更好。该技术可广泛应用于各种游梁式抽油机,对抽油机举升节能降耗具有重大意义。

The conventional beam pumping units sometimes have such problems as poor balance and large energy consumption under the normal working condition.To solve the problems mentioned above,the variable speed drive technology for beam pumping units has been developed by controlling the motor speed to adjust the system running condition and to reduce the energy consumption.Based on the concept of balanced power speed adjustment,slow drive for heavy load and fast drive for light load,the kinematics and dynamics model of pumping unit with variable speed has been established.The solution of system simulation model has been found by means of nonlinear coupling method.It is found that the variable speed curves of all motors basically follow the changing law of the saddle-shape curves.Taking the minimum instantaneous power of motor output as the optimal target,the variable speed operation mode was optimized.The results showed that the crank rotation angular velocity peak reduced by 3.5%,while the speed at suspension point reduced by 24.96%,and the instantaneous power peak of crank lowered by 28.6%when compared the optimal variable speed curves with the original ones,which proves that the energy saving effect of optimal variable speed curve is better.This technology can be widely used in all kinds of beam-pumping wells with great significance to save the energy and lower the consumption in pumping unit lifting.