Research On Model Of Pump’s Working Performance

According to the questions of low system efficiency and large energy consumption,combined with the domestic and foreign relevant research results, based on gas-liquidtwo-phase flow and fluid dynamics theory,starting with the factors influencing operatingcharacteristics of pump,a model of plunger piston motion law have been built based on themotion law of point of suspension;After that,based on the plunger piston motion law,considering the change of pump intake pressure,the model of producing fluid level variationmodel and valve ball motion law have been built. The results show that,under the influenceof fluid into the pump and valve housing,the value fluctuates by leaps and bounds,then it willkeep a state of suspension. The producing fluid level keeps a steady state at the macrolevel,during a stroke, amplitude of variation is very small at the micro level.The valve ballmotion law is affected by stroke time、viscosity、producing air/oil ratio and water cut and etc.There is delay time during opening and shuting of value. The delay time of value opening isinversely proportional to stroke time、viscosity and water cut, and it is proportional toproducing air/oil ratio.The delay time of value shuting is contrary to that of value opening.Analysis of fluid viscosity and flow into the pump, the dynamic process of fluid of the valveis investigated by the FLUENT software.The influences of parameters(velocity、density、viscosity)on the resistance of fluid flowing into pump are analysised and the resistancemodels of fluid flowing into pump for the pump diameter of31.8mm、38.1mm、44.5mm、57.2mm and69.9mm are obtained. Based on the above researches,the models of pumpefficiency and system efficiency are established,the retionship of submergence depth underdifferent water cuts (0%、20%、40%)、different producing air/oil ratios (30m3/m3、40m3/m3、50m3/m3)、different strokes (2.1m、2.5m、3m) and stroke times(4min-1、6min-1、8min-1) withpump efficiency and system efficiency are obtained.If pump efficiency is regarded as theoptimal object, reasonable submergence depths are equal under different water cuts and itincreases with the increase of producing air/oil ratio、stroke time and stroke.Whensubmergence depth is less than reasonable submergence depth, pump efficiency increaseswith the increase of water cut under the equal submergence depth.When submergence depth is more than reasonable submergence depth, pump efficiencys are equal generally underdifferent water cuts. The pump efficiency increases with the decrease of air/oil ratios within acertain limits of submergence depth and it decreases with the increase of stroke and stroketime. If system efficiency is regarded as the optimal object, reasonable submergence depthdecreases with the increase of water cut and it increases with the increase of air/oil ratio andstroke,but it doesn’t have deterministic relation with stroke time. The system efficiencyincreases with the increase of water cut under the same submergence depth, and it increaseswith the decrease of air/oil ratio within a certain limits of submergence depth. It providestheoretical guidances to choose the pump and optimizing reasonable production parametersand increasing pump efficiency and system efficiency.