乳化液泵配流机理的理论研究与试验分析

利用流体可压缩性、流量连续方程及阀口流量公式建立了单柱塞腔流动特性方程;在考虑了重力、弹簧力、压差力、接触力及液动力基础上,建立了配流阀动力学模型;以排液歧管过流孔道为控制体积,建立了包含3个柱塞腔、蓄能器及负载的整泵流动特性方程。用AMESim软件创建了具有3柱塞结构的BRW125/31.5C型乳化液泵模型,将不同曲轴转速下的配流阀阀芯位移及泵出口压力的仿真值与试验值对比,验证了理论分析与仿真模型的正确性。结果表明:当该型号泵驱动电机输入频率分别为50, 40, 30 Hz时,上流量脉动率分别为1.25%,1.19%,1.37%,而下流量脉动率分别为1.76%,1.73%,1.76%;柱塞腔内流场在从低压向高压转换时存在压力冲击;在吸、排液行程转换阶段,存在流量倒灌现象。

Theoretical Study and Experimental Analysis on Flow Distribution Mechanism of Emulsion Pump

A mathematical model of flow condition in single plunger chamber is developed with fluid compressibility, flow continuity equations, and valve port flow formula ; by taking gravity, spring, pressure, contact, and flow forces into account, we establish a dynamics model of flow distribution valve; by taking flow passage of outlet manifold as the control volume, we establish a flow condition model of the complete pump. Based on AMESim, a simulation model of BRW125/31.5C emulsion pump which has 3 plungers is developed . We verify the effectiveness and accuracy of theoretical analysis and simulation models by comparing the simulation values of valve core displacement and pump outlet pressure at different crankshaft speeds with the experimental values. The simulation results show that: when the input frequency of pump drive motor is 50 Hz, 40 Hz and 30 Hz respectively, the upper flow ripple rate of this type of emulsion pump is about 1.5%, 1.19% and 1.37%, while the lower flow ripple rate of this type of emulsion pump is about 1.76%, 1.73% and 1.76%, respectively; there is a cylinder pressure impact during the transition from low-pressure to high-pressure; there is a flow backward phenomenon in the conversion stage of suction and discharge stroke.