乳化液泵配流系统的数值模拟及可视化分析

发布时间：2018-10-16 14:25

【摘要】：乳化液泵是煤矿综采装备中极为重要的动力源，其工作的稳定性、连续性、高效性是提高煤炭产量、保障安全生产及改善收益结构的根本要素。乳化液泵配流系统的性能优劣直接决定了整个乳化液泵站的工作效率。因此，为了提高乳化液泵的综合性能，本论文利用虚拟样机技术对乳化液泵的配流系统进行了较为全面的研究，为配流阀的结构设计及特性优化提供了指导方向及改进方法。本论文首先在考虑配流阀滞后及气穴现象等因素的基础上，对乳化液泵机构的运动学数学模型进行了阐述，建立了单个柱塞腔的理想及实际流量模型及压力模型。然后，运用AMESim模拟得到了配流系统的运动特性，并着重分析了乳化液泵流量波动及压力冲击等现象。分析表明：在乳化液泵吸液初期及排液末期，柱塞腔出现了约为-0.2MPa的瞬时负脉冲；排液阀阀芯对限位装置撞击剧烈，而吸液阀阀芯主要对阀座冲击严重；此外，排液阀开启至最大高度过程中，产生了幅值约为0.4mm的瞬时“振颤”现象。此外，论文针对配流阀滞后响应的影响因素进行了综合分析，讨论了不同结构参数及工作参数的影响规律。结果表明：吸液阀关闭滞后和排液阀的开启滞后随曲轴半径、连杆长度、柱塞直径及吸液阀阀芯质量的增加而增大，随吸液阀弹簧刚度及预压力的增加而减小；而吸液阀的开启滞后和排液阀的关闭滞后随排液阀阀芯质量的增加而增大，随排液阀弹簧刚度的增加而减小。此外，随着阀芯半锥角的增加，工作压力的提高，配流阀的滞后现象均随之减弱；余隙容积对开启滞后时间影响显著，而对关闭滞后影响不大。最后，论文以低能耗、低噪声为目标，利用Fluent对配流阀流场进行了可视化分析。结果显示：节流口处出现了高达16.7m/s的高速射流，并在阀芯弯角处产生高达-0.123MPa的局部负压。针对压力场、速度场及湍流动能图等仿真结果改进了流道型式，将阀芯锥面与柱面线性相接改为圆弧过渡，当过渡半径为1.5mm时，最大流速可降至15m/s，且局部负压值降至-0.05MPa，实现了配流系统的减振降噪及能量利用率的提高。
[Abstract]:Emulsion pump is a very important power source in fully mechanized coal mining equipment. The stability, continuity and efficiency of its work are the fundamental factors to improve coal production, ensure safe production and improve income structure. The performance of emulsion pump distribution system directly determines the working efficiency of the whole emulsion pump station. Therefore, in order to improve the comprehensive performance of the emulsion pump, the flow distribution system of the emulsion pump is studied comprehensively by using the virtual prototyping technology in this paper, which provides the guiding direction and the improvement method for the structure design and characteristic optimization of the distribution valve. On the basis of considering the hysteresis of flow distribution valve and cavitation phenomenon, the kinematics mathematical model of emulsion pump mechanism is expounded, and the ideal and actual flow model and pressure model of single plunger cavity are established. Then, the motion characteristics of the flow distribution system are obtained by AMESim simulation, and the flow fluctuation and pressure impact of the emulsion pump are analyzed. The analysis shows that during the initial stage of suction and the end of liquid discharge of the emulsion pump, the instantaneous negative pulse of about-0.2MPa appears in the plunger cavity; the valve core of the drain valve impinges violently on the limiting device, while the valve core of the suction valve mainly impacts the valve seat seriously; in addition, the valve core of the drain valve has a severe impact on the valve seat. In the process of opening the valve to the maximum height, the transient "vibration" phenomenon with amplitude of about 0.4mm is produced. In addition, the influence factors of the hysteresis response of the distribution valve are comprehensively analyzed, and the influence laws of different structure parameters and working parameters are discussed. The results show that the closing lag of the suction valve and the opening lag of the drain valve increase with the increase of the radius of the crankshaft, the length of the connecting rod, the diameter of the plunger and the mass of the valve core, but decrease with the increase of the spring stiffness and the pre-pressure of the suction valve. However, the opening lag of the suction valve and the closing lag of the drain valve increase with the increase of the valve core mass, and decrease with the increase of the spring stiffness of the drain valve. In addition, with the increase of the half cone angle of valve core and the increase of working pressure, the hysteresis of flow distribution valve is weakened, and the clearance volume has a significant effect on the opening lag time, but has little effect on the closing lag time. Finally, the flow field of flow distribution valve is analyzed visually by Fluent, aiming at low energy consumption and low noise. The results show that there is a high speed jet up to 16.7m/s at the throttle and a local negative pressure of up to-0.123MPa at the corner of the valve core. For the simulation results of pressure field, velocity field and turbulent kinetic energy diagram, the flow channel type is improved. The linear connection between the cone and cylinder of the valve core is changed to arc transition. When the transition radius is 1.5mm, The maximum velocity of flow can be reduced to 15 m / s, and the local negative pressure to -0.05 MPA, which can reduce vibration and noise and improve the energy efficiency of the distribution system.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD421.8

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