A Method Of Suppressing Pulsation At The Source Of High-pressure Reciprocating Pump Based On Non-circular Gear

Reciprocating pump is a high-pressure volumetric pump with strong self-priming ability and a wide application range,suitable for conveying high viscosity,flammable and explosive,highly corrosive and highly toxic liquid,which has wide application in petroleum,chemical industry,metallurgy,fire-fighting,naval and other fields.However,violent flow pulsation is produced in reciprocating pumps during operation,which will induce significant vibration and noise in the pipeline and pump body,giving rise to adverse effects on the staff and the conveying system.Therefore,a pulsation elimination method based on non-circular gear transmission was proposed in this paper,which has important application value for suppressing the flow pulsation of high-pressure reciprocating pumps.Reverse design the theoretical transmission ratio of non-circular gear for flat suppression according to the principle of triplex reciprocating pump.Aiming at the closed problem of non-circular gears,a pitch curve design method based on Fourier series was proposed,and the flow after flattening was analyzed theoretically.The results show that the installation phase error of driven non-circular gear and reciprocating pump crank will cause additional flow pulsation,and the installation accuracy needs to be strictly controlled.The tooth profile model of non-circular gear for pulsation elimination was established,the calculation method of module and tooth number was given based on the basis of the undercut judgment of non-circular gear,and the geometric design method of non-circular gear for flat suppression was formed,and the static load analysis was completed by finite element method.It is found that the non-circular gear pair produces the maximum stress at the location of the minimum radial diameter of the driving non-circular gear,which is used as the reference position for the strength design of the flat non-circular gear.The flow simulation model of triplex reciprocating pump was established by using fluid dynamics simulation software and considering the influence of valve element hysteresis,three pulsation suppression schemes of non-circular gear,accumulator and their combination were simulated respectively.The results show that the non-circular gear can significantly reduce the flow pulsation caused by the structure of the reciprocating pump,but has no effect on the pulsation caused by the lag of the check valve,when the accumulators are used together,a nearly uniform instantaneous flow can be obtained.Finally,the mechanical end test platform of the reciprocating pump driven by noncircular gear was built,and the acceleration data of the piston at the mechanical end was collected,the theoretical and experimental data are basically consistent,which indirectly verifies the feasibility of the method of reducing the pulsation at the source of reciprocating pump based on non-circular gear drive.