考虑漏失的抽油泵示功图的计算机仿真模型

综合考虑柱塞的运动规律、泵筒内流体的可压缩性、柱塞与泵筒之间的间隙漏失量,建立了泵筒内流体流动的连续流方程。根据改进的连续流方程,建立了泵筒内液体压力、柱塞运动规律与柱塞泵筒间隙之间相互关系的数学模型,从而建立了泵筒内液体瞬时压力与泵示功图的仿真模型。仿真分析了柱塞与泵筒之间不同间隙时,泵筒内液体压力变化规律的时间历程曲线和泵示功图。仿真分析结果表明,柱塞与泵筒之间的间隙漏失不仅会导致固定阀滞后打开,而且会导致游动阀提前关闭。当间隙增大到一定程度时,会出现固定阀无法打开而导致抽油泵完全失效的状态。所建立的数学模型为完善漏失状态抽油机井动态参数的计算机仿真技术提供了理论基础。

Computer Simulation of Leakage Dynamometer Card of Oil Well Pump

The movement of plunger piston,the compressibility of the liquid and the leakage in the clearance between the plunger piston and pump barrel were comprehensively considered,and a new continuous flow equation of the fluid in the pump cylinder was setup. On the basis of improved continuous flow equation,the mathematical model that expresses the interrelationship of the liquid pressure,the movement of plunger piston and the pump barrel clearance were setup,and simulating models of the liquid instantaneous pressure in the pump barrel and the pump dynamometer were established. The changing curves of liquid pressure with time and the pump dynamometers were simulated when the e clearance between the plunger piston and pump was of different values. The following conclusions can be obtained:(1) the clearance leakage between the plunger piston and pump barrel not only lead to delaying opening of the static valve,but also lead to advancing closing of the traveling valve;(2)when the clearance leakage between the plunger piston and pump barrel is more then some value,the static valve is in the closing state in the wholly moving cycle,and the pump can not work.The established mathematical modes provide the theory basis for further improving the simulating technique of dynamic parameters of rod pumping system.