多级泵平衡盘间隙流动的理论分析

本文针对多级泵平衡盘装置中两个间隙窄且长的特点,提出流动为层流运动的假设,进而简化了N－S方程,推导出了两个间隙的几何参数与泄漏量和平衡力之间的函数关系,经过实例计算证明,上述公式是对平衡盘工作过程中进行理论分析的有效方法之一。     

多级泵平衡盘动态平衡分析

分析多级泵平衡盘动态平衡原理，推导出平衡盘轴向间隙计算公式，提出水泵安装时控制平衡盘轴向间隙的方法。     

无平衡盘多级泵的结构设计

传统的D型多级泵的轴向力平衡采用平衡盘/平衡环机构进行平衡,但是井下大型多级泵的平衡盘/平衡环更换麻烦,维修工作量大,如果有一种结构能够降低平衡盘/平衡环的更换频率甚至不用更换,即使增加制造成本同时牺牲部分水力性能也是有益可取的.文中通过定性分析探讨了一种无平衡盘/平衡环结构的多级泵.     

平衡鼓间隙尺寸对多级泵轴向平衡能力影响的分析

利用CFD软件模拟分析了6种不同平衡鼓间隙尺寸情况下的泵内流动情况,预测了间隙入口处压力及速度分布。模拟结果显示,平衡鼓间隙与两侧压差及间隙泄漏量均为非线性变化关系,验证了已有间隙泄漏量公式的合理性。研究结果表明,平衡鼓间隙尺寸对轴向平衡能力以及间隙泄漏量均具有较大影响,在保证设备安全运行的前提小,间隙尺寸应当尽量小。     

多级泵平衡盘动态平衡的理论研究

基于多级泵平衡盘的结构特点和工作原理,分析了平衡盘运动平衡的过程。利用连续方程和动量方程对平衡盘间隙流动进行了研究,推导出了平衡盘动态平衡力的函数表达式。进而,根据作用在平衡盘-转子系统上力的动态平衡建立了该系统的运动方程,理论上得到了多级泵平衡盘轴向位移与时间的关系,为研究平衡盘-转子系统的动态性能和轴向振动提供了理论基础。     

分段式多级水泵平衡盘轴向最佳间隙的分析

分析了分段式多级水泵工作中轴向位移及其影响因素的理论，研究平衡盘运动规律和轴向间隙变化情况，目的是探讨平衡盘轴向最佳间隙值，使水泵轴向力变化时，转子轴向位移最小，以提高水泵工作可靠性及其使用寿命。     

平衡盘间隙流动分析及最佳刚度计算

根据平衡盘问隙流动的特点，对粘性流体N-S方程进行了简化，求得平衡盘问隙流动速度、压力、泄漏量和平衡力等参数，并探讨了平衡盘最佳刚度与其结构参数、轴向间隙的关系，得出了灵敏度的取值范围。     

平衡盘型多级泵轴向振动超标的原因及对策

轴向振动超标是多级泵运行中常见的故障。过大的轴向振动可引起轴承损坏、机械密封泄漏和动静碰摩等严重事故。本文阐述了平衡盘的工作原理及轴向振动的不可避免性;从泵的选型、平衡盘与平衡板的材料、平衡板与泵体间的泄漏等方面分析了平衡盘多级泵轴向振动超标的原因,并提出了有针对性的解决措施。     

平衡盘几何参数的优化设计

针对节段式多级泵平衡盘泄漏量较大的特点，以泄漏量最小为目标函数，对平衡盘主要几何参数进行了优化计算。     

新型径向恒流柱塞泵的设计

本文提出了新型的恒流柱塞泵的理论分析和设计，针对柱塞泵的运动情况，阐述了为实现柱塞泵的无流量脉动的柱塞的运动速度曲线所必须具备的特征，导出了几种常见的恒流特征速度曲线，并设计了径向恒流柱塞泵。     

Predicting performance of radial flow type impeller of centrifugal pump using CFD

The main objective of this work is to use the computational fluid dynamics (CFD) technique in analyzing and predicting the performance of a radial flow-type impeller of centrifugal pump. The impeller analyzed is at the following design condition: flow rate of 528 m³/hr; speed of 1450 rpm; and head of 20 m or specific speed (N_s) of 3033 1/min in US-Units. The first stage involves the mesh generation and refinement on domain of the designed impeller. The second stage deals with the identification of initial and boundary conditions of the mesh-equipped module. In the final stage, various results are calculated and analyzed for factors affecting impeller performance. The results indicate that the total head rise of the impeller at the design point is approximately 19.8 m. The loss coefficient of the impeller is 0.015 when 0.6 < Q/Q_design < 1.2. Maximum hydraulic efficiency of impeller is 0.98 at Q/Q_design = 0.7. Based on the comparison of the theoretical head coefficient and static pressure rise coefficient between simulation results and experimental data, from previous work reported in the literature [Guelich, Kreiselpumpen, Springer, Berlin, 2004], it is possible to use this method to simulate the performance of a radial-flow type impeller of a centrifugal pump. This paper was recommended for publication in revised form by Associate Editor Seungbae Lee Somchai Wongwises is currently a Professor of Mechanical Engineering at King Mongkut’s University of Technology Thonburi, Bangmod, Thailand. He received his Doktor Ingenieur (Dr.Ing.) in Mechanical Engineering from the University of Hannover, Germany, in 1994. His research interests include two-phase flow, heat transfer enhancement, and thermal system design. Professor Wongwises is the head of the Fluid Mechanics, Thermal Engineering and Two-Phase Flow Research Laboratory (FUTURE). Suthep Kaewnai obtained a B. S. degree in Mechanical Engineering, 1980 from the King Monkut’s University of Technology Thonburi and M. S. degree in Mechanical Engineering, 1983 from Chulalongkorn University. He is currently an assistant professor at King Mongkut’s University of Technology Thonburi. Suthep’s research interests are in the area of pumps and small hydroturbine. Manuspong Chamaoot received a B. S. degree, 1972 and M.S. degree in Mechanical Engineering, 1979 from the King Monkut’s University of Technology Thonburi. He is currently an assistant professor at King Monkut’s University of Technology Thonburi. His research interests are in the field of mechanical vibration for rotating equipment and computational fluid dynamics.     

电动燃油泵叶轮间隙测试误差分析

叶轮间隙的大小直接影响燃油泵的性能,对叶轮间隙测试系统的机械结构进行设计并对误差作出分析,阐述了叶轮间隙检测装置的评定方法,为同类测试设备的验收评定提供了依据.试验结果表明:该测试装置测试性能稳定可靠,测试精度满足设计要求.     

滚动轴承径向游隙的合理确定

游隙是滚动轴承配合的一个重要技术参数,它直接影响轴承的载荷分布、振动、噪声、磨损、温升、使用寿命和机械运转精度等技术性能。轴承的基本额定动负荷是随着游隙的大小而变化的,轴承样本中的基本额定动负荷是轴承工作游隙为零时的推荐值。如果游隙过大,在极端情况下可能只有最下方一个滚动体受力,轴承承载能力将大大降低,滚动接触面应力增大,轴承的运转精度下降,振动和噪声增大,使用寿命缩短;如果游隙过小,会引起轴承发热,温度升高,甚至使轴承在运转中发生咬死现象。因此根据轴承类型、工作条件等合理选择轴承游隙是十分必要的。     

原油外输泵的内流场动力学仿真分析

针对某油田原油外输站内1#泵出现的异常振动现象,采用ANSYS软件对原油外输泵泵内的流场动力学进行了仿真分析.首先,采用SolidWorks建立了原油外输泵的三维模型,并进行了流体域抽取;然后,对外输泵的模型进行了网格划分,并进行了网格无关性的验证;选择了正常工作下外输泵的参数作为边界条件,通过动力学仿真对常用转速和流...     

Numerical simulation and analysis of solid-liquid two-phase flow in centrifugal pump

The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the two-phase flow pumps,i.e.,low overall efficiency and severe abrasion.In this study,the three-dimensional,steady,incompressible,and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics(CFD) code based on the mixture model of the two-phase flow and the RNG k-two-equation turbulence model,in which the influences of rotation and curvature are fully taken into account.The coupling between impeller and volute is implemented by means of the frozen rotor method.The simulation results predicted indicate that the solid phase properties in two-phase flow,especially the concentration,the particle diameter and the density,have strong effects on the hydraulic performance of the pump.Both the pump head and the efficiency are reduced with increasing particle diameter or concentration.However,the effect of particle density on the performance is relatively minor.An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration.The suction side of the blade is subject to much more severe abrasion than the pressure side.The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump,and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.     

隔膜计量泵的排量误差分析和远程补偿

计量泵作为一种能够按照比例调节排量的计量设备,其主要性能指标是计量精度。为了解决实际的工业控制中计量泵的计量精度误差问题,以及恶劣环境下手动调节计量泵的局限性问题,对制造工艺、流体粘度系数等因素所造成的计量泵排量误差值进行了计算与分析,提出了一种基于CAN总线和以太网的计量泵远程网络控制系统。通过协议转换器将实时性强的CAN现场总线网络与通信距离远、通信速率高的以太网相连,运用模糊控制算法,对不同工作条件下的计量泵组进行实时的远程补偿,以达到精确的排量控制。实验结果表明,计量泵远程网络控制系统稳定性高,速率调节快,能够有效提高计量泵的输出精度,实现精确的远程流体定比投加控制。     

气旋转接头缝隙泄漏流动参数敏感性分析

缝隙泄漏是影响非接触密封型气旋转接头性能的一个重要因素,研究其泄漏流动特性对气旋转接头设计具有重要意义。根据非接触密封型气旋转接头结构原理,将环形缝隙泄漏流动合理简化为二维等截面直管流动,采用正交试验设计原理,通过数值模拟分析了气旋转接头泄漏流动气体参数变化规律;以工程上最为关注的最低气体温度和泄漏流量为评估指标,分析了气体工质压力、泄漏间隙结构参数对缝隙泄漏的影响。研究结果表明,经缝隙泄漏气体产生膨胀,气体压力、马赫数和温度沿流动方向的变化规律因气体工质压力不同而不同。影响最低温度的主要因素是气体工质压力,次要因素是泄漏间隙结构参数;当气体工质压力越大,泄漏间隙越宽、越短时,最低温度越小,泄漏流量越大。     

对转轴流泵的设计与数值分析

对转轴流泵是由2个叶轮串联在一起,以相反的方向绕同一轴心旋转的轴流泵.与常规前、后导叶式轴流泵相比,在同样设计参数条件下,对转式轴流泵具有相对体积小、运转速度低、抗空化性能好和推重比高等特点.为探究对转轴流泵的设计理论和方法,设计了一对转轴流泵的前、后置叶轮,应用Matlab软件实现参数化设计,搭建了自动分析优化平台,...