水动比例注入泵性能参数研究

发布时间：2018-07-04 20:35

本文选题：比例注入泵 + 动网格　；参考：《江苏大学》2017年硕士论文

【摘要】：比例注入泵是一种高精度、可调节的定量施肥装置,比例可调、水力驱动是其主要特点。目前对于比例注入泵的产品性能研究较多,但运行机理和性能参数研究不足,无法为注入泵设计提供足够的理论指导,同时研发手段有限导致市场上的产品大多是仿制国外。因此,通过数值模拟方法研究和性能参数研究来建立系统的比例注入泵设计方法具有重要的学术意义和工程意义。本文在比例注入泵机理分析的基础上编译用户自定义程序,采用流固耦合中的动网格技术对其进行数值模拟,通过实验验证了模拟方法的可行性和准确性,通过分析注入泵的内部流动和活塞受力,研究进出口直径、进口腔直径、驱动腔直径、进水阀口直径、出水阀口直径以及换向弹簧刚度对比例注入泵水力性能的影响;研究吸肥腔结构参数对比例注入泵吸肥性能的影响。主要研究工作包括以下几方面:1.结合比例注入泵运行原理进行驱动活塞的力学分析,利用C语言和宏编译UDF,采用数值方法对注入泵的运行过程进行模拟。进行高速摄影实验,对比模拟、实验结果验证模拟方法的可行性和准确性,分析注入泵内部流动和受力。结果表明:驱动活塞的运动特性是先加速再匀速,其第一、三表面受力较稳定,第二表面受力是先减小或增大再趋于稳定。在工作范围内,模拟和实验平均流量的最大误差为4.20%,活塞运动频率最大误差为20.95%,活塞运动规律基本相同,说明模拟方法准确可行。2.采用动网格方法研究水力驱动机构结构参数对比例注入泵水力性能的影响,结构参数主要包括:进出口直径、进口腔直径、驱动腔直径、进水阀口直径和出水阀口直径。同时通过实验研究换向弹簧刚度系数对水力性能的影响。结果表明:随着进出口直径增大,平均流量和活塞运动频率增大并趋于平稳,22mm时两者都达到最大值;平均流量与进口腔直径成正比,随着腔径增大,活塞运动频率升高并趋于平稳,流量脉动削弱,71mm时流动脉动系数最小;随着驱动腔直径增大,平均流量呈波动式下降,流量脉动逐渐增强,100mm时脉动程度最弱。活塞运动频率减小并趋于稳定;进水阀口直径增大导致平均流量呈线性递增。活塞运动频率增大并趋于稳定,19mm时流量脉动最小。平均流量和运动频率都与出水阀口直径成正比,12mm时流量脉动最弱。换向弹簧刚度系数对比例注入泵水力性能影响不显著,但刚度系数越小,其启动压力越小,承压能力越弱。3.搭建比例注入泵水力性能测试实验台,通过实验研究吸肥腔结构参数对注入泵吸肥性能的影响。吸肥腔结构参数包括压差、进口流量、吸肥腔直径、配合公差以及单向阀弹簧刚度。结果表明:随着压差增大,注入泵吸肥量增大并趋于平缓,拟合出吸肥量、压差以及吸肥比例的回归模型,吸肥量与进口流量成正比;吸肥腔直径增大导致注入泵吸肥量迅速增大,但直径较小的吸肥腔的吸肥效率较高;活塞垫圈与腔体过盈量为0.5mm时吸肥性能最优,过小或者过大的过盈量都会导致密封性变差。单向阀弹簧刚度在一定范围内不影响吸肥性能,但超过一定值后,注入泵失去吸肥功能。
[Abstract]:Proportional injecting pump is a kind of high precision and adjustable quantitative fertilization device, which is adjustable in proportion and hydraulic drive is its main characteristic. At present, there are many research on the product performance of the proportional injecting pump, but the research of operation mechanism and performance parameter is insufficient, and it can not provide sufficient theoretical guidance for the design of injection pump. At the same time, the limited research and development means are limited to the market. Most of the products are copied from abroad. Therefore, it is of great academic and engineering significance to establish the design method of proportional injection pump by numerical simulation method and performance parameter research. In this paper, the user custom program is compiled on the basis of the mechanism analysis of proportional injection pump, and the dynamic grid technology in fluid solid coupling is used in this paper. Through the numerical simulation, the feasibility and accuracy of the simulation method are verified by the experiment. Through the analysis of the internal flow and the piston force of the injection pump, the influence of the diameter of the inlet and outlet, the diameter of the cavity, the diameter of the driving cavity, the diameter of the inlet valve, the diameter of the inlet valve and the stiffness of the spring and the change of the spring stiffness on the hydraulic performance of the proportional injecting pump are studied. The main research work includes the following aspects: 1. combined with the operation principle of the proportional injection pump, the mechanical analysis of the driving piston is carried out. The C language and the macro compiled UDF are used to simulate the operation process of the injection pump. The high speed photography experiment, the comparison simulation and the experimental results are carried out. The feasibility and accuracy of the simulation method are verified and the internal flow and force of the injection pump are analyzed. The results show that the motion characteristics of the driving piston are first acceleration and then uniform speed, the first, third surface stress is more stable, the second surface stress is first reduced or increased and then tends to stability. The maximum error of the simulated and experimental average flow is 4.2 within the working model. 0%, the maximum error of piston motion frequency is 20.95%, and the motion law of the piston is basically the same. It shows that the simulation method is accurate and feasible.2. uses the dynamic grid method to study the influence of the hydraulic driving mechanism on the hydraulic performance of the proportional injecting pump. The structural parameters mainly include the diameter of the import and export, the diameter of the inlet, the diameter of the driving cavity, the diameter of the inlet valve mouth and the diameter of the inlet valve. The effect of the stiffness coefficient of the reversing spring on the hydraulic performance was studied by experiments. The results showed that the average flow rate and the piston motion frequency increased and tended to be stable with the increase of the inlet and outlet diameter. The average flow rate reached the maximum at 22mm, and the average flow rate was proportional to the direct diameter of the mouth. With the increase of the cavity diameter, the piston movement frequency was increased. With the increase of the flow fluctuation and the weakening of the flow pulse, the flow coefficient of the 71mm flow is the smallest. With the increase of the diameter of the driving cavity, the average flow is fluctuating, the flow pulsation increases gradually, the fluctuation degree is the weakest at 100mm. The piston motion frequency decreases and tends to be stable; the average flow of the inlet valve opening increases linearly and the piston movement frequency increases. The rate increases and tends to stabilize, the flow pulsation is the smallest at 19mm. The average flow and motion frequency are proportional to the diameter of the valve outlet, and the flow pulsation is the weakest at 12mm. The change of the stiffness coefficient of the reversing spring has no significant influence on the hydraulic performance of the proportional injecting pump, but the smaller the stiffness coefficient, the smaller the starting pressure, the weaker the capacity of.3. to build the pump water. The effect of the structure parameters of the suction chamber on the performance of the injection pump is investigated by the force performance test bench. The structure parameters of the suction chamber include the pressure difference, the inlet flow, the diameter of the suction cavity, the tolerance and the stiffness of the unidirectional valve spring. The results show that the amount of fertilizer absorption and the pressure difference of the injection pump increase with the increase of pressure difference, and the amount of fertilizer absorption and the pressure difference are fitted. As well as the regression model of the proportion of fertilizer absorption, the amount of fertilizer absorption is proportional to the inlet flow rate, and the increase of the diameter of the injection pump increases the amount of the injection pump rapidly, but the efficiency of the fertilizer suction is higher in the smaller diameter suction chamber, and the performance of the sucking is the best when the piston washer and the volume of the cavity are 0.5mm, and the oversize or excessive interference will result in the difference of the sealing property. The stiffness of the valve spring does not affect the performance of the fertilizer in a certain range, but after a certain value, the injection pump loses the function of absorbing fertilizer.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH38

【参考文献】