螺旋离心泵内部流动和能量转换机理的研究
发布时间：2019-06-07 20:32
【摘要】：螺旋离心泵是一种具有特殊结构与效率优于离心式杂质泵和旋流式杂质泵的固液两相流泵，将螺旋泵与离心泵融合为一体，其独特的结构可将两者的优势充分发挥。相比其他杂质泵，螺旋离心泵具有良好的无堵塞性、吸入性能、调节性能和抗汽蚀性能，并具有无过载、效率高及高效区宽等优点。 长久以来，泵类产品能量利用率的提高问题，一直困扰着泵行业工作者，如何在同等工况下，获得较高的效率，是泵行业工作者最为关心的问题。相对于离心泵，螺旋离心泵的效率普遍较低，也就是说螺旋离心泵的效率仍具有较大的提升空间。而叶轮作为螺旋离心泵的重要元件，，甚至可以说是螺旋离心泵的心脏，叶轮的叶片形状对叶轮的水动力特性具有决定性的影响，在很大程度上决定着该泵的效率。对于输送固液两相流介质的螺旋离心泵来说，由于其叶轮内水流状态的复杂性，一元流动理论和经验设计方法难以满足设计优良水力性能叶轮的需要；从固液两相介质在螺旋离心泵叶轮内的运动状态来看，其叶轮使得流体完成从轴向至径向的过渡，液流的轴向速度由大变小，径向速度则相反，这就要求叶片的螺距从进口至出口要做由大到小的平滑变化。因此，探究叶轮能量转换机理和叶轮各个部分内的流动与做功情况，可以为叶轮的合理设计提供更有效地改进方案。 本文针对螺旋离心泵能量转换机理的主要研究，内容如下： 一方面从理论上分析了流体机械内部的流体流动情况，应用欧拉方程，将流体在叶轮中的能量分为动压头和静压头来处理，为数值模拟来研究螺旋离心泵内部流动和叶轮各段的做功能力提供了理论基础；另一方面通过数值模拟，分析了叶轮作用下内流场的压力分布、速度分布以及固相浓度分布，由此得出了螺旋离心泵能量转换机理以及与其优越的抗堵塞特性和无损特性等产生的内在联系。 本文的创新性主要有： 1）应用流体机械的欧拉方程，将叶轮转换的能量分为动压头和静压头来解释螺旋离心泵的能量传递和转化规律； 2）研究螺旋离心泵的压力场和速度场沿叶轮的分布规律，并将螺旋离心泵叶轮的轮缘线和轮毂线分段，分别从动压头和静压头变化分析螺旋离心泵的能量沿叶轮包角的转换能力，对于螺旋离心泵的性能提高和设计理论的完善具有很好的指导意义。 通过理论分析和数值计算，从螺旋离心泵能量的总体转换性能，具体探讨了设计工况下，介质分别为清水和固液两相流的沙水时流场的速度、压力、流线、水力损失等，对其全流道流动的数值模拟结果进行了定性与定量对比分析，获得主要结论如下： 1)沿包角的由小到大，相对速度的总体变化局势是逐渐增大的，在很小的区段略有降低，这在一定的程度上降低了螺旋离心泵效率的提高； 2)在螺旋离心泵叶轮做功过程中，螺旋段的静压头和动压头的整体是增加的，而在离心段则不一定。在最大半径处，静压头达到了最大，说明螺旋离心泵的扬程主要是螺旋段产生的，叶轮前部螺旋段起到了多级加能的作用，这也验证了螺旋段在叶轮做功中起着主要作用； 3)在两相流湍流运动的情况下，由于力场的不同，在螺旋离心泵叶轮螺旋推进和离心作用下，使得固液两相以不同的速度运动。螺旋离心泵在模拟工况下能量转换主要是液体的能量变化，固相是在液体的裹协下运动，固体能量是通过液体间接进行的。
[Abstract]:The spiral centrifugal pump is a solid-liquid two-phase flow pump with special structure and efficiency, which is superior to the centrifugal type impurity pump and the swirl type impurity pump, and the spiral pump and the centrifugal pump are integrated into a whole, and the unique structure of the spiral centrifugal pump can fully play the advantages of both. Compared with other impurity pumps, the spiral centrifugal pump has the advantages of good non-blocking property, suction performance, regulating performance and anti-cavitation performance, and has the advantages of no overload, high efficiency and wide effective area. For a long time, the improvement of the energy utilization rate of the pump products has been a problem in the pump industry, and how to achieve higher efficiency under the same working conditions is the most concerned question of the pump industry. The efficiency of the spiral centrifugal pump is generally lower with respect to the centrifugal pump, that is, the efficiency of the spiral centrifugal pump still has a large lift The impeller, as an important component of the spiral centrifugal pump, can even be said to be the heart of the spiral centrifugal pump, the blade shape of the impeller has a decisive influence on the hydrodynamic characteristics of the impeller, and the effect of the pump is determined to a great extent. In the case of the spiral centrifugal pump for solid-liquid two-phase flow media, because of the complexity of the water flow state in the impeller, the one-way flow theory and the empirical design method are difficult to meet the need of designing an excellent hydraulic performance impeller, and the motion state of the solid-liquid two-phase medium in the impeller of the spiral centrifugal pump it is to be seen that the impeller causes the fluid to complete the transition from the axial to the radial direction, the axial velocity of the liquid stream being large, the radial velocity being the opposite, which requires that the pitch of the blade be changed from the inlet to the outlet from large to small Thus, the mechanism of the energy conversion of the impeller and the flow and the working condition of each part of the impeller can be explored, and the reasonable design of the impeller can be provided with more effective improvement. In this paper, the main research of the mechanism of the energy conversion of the spiral centrifugal pump is given in this paper. The results are as follows: On the one hand, the fluid flow in the fluid machine is theoretically analyzed, the Euler equation is applied, and the energy of the fluid in the impeller is divided into dynamic pressure head and static pressure head. The pressure head is used to deal with, and the numerical simulation is used to study the internal flow of the spiral centrifugal pump and the work ability of each section of the impeller. On the other hand, the pressure distribution, the velocity distribution and the solid structure of the inner flow field under the action of the impeller are analyzed by numerical simulation. In this paper, the energy conversion mechanism of the spiral centrifugal pump and its superior anti-clogging and non-destructive characteristics are obtained. The internal relation of this article. The innovation of the invention is mainly as follows:1) the Euler equation of a fluid machine is applied, the energy converted by the impeller is divided into a dynamic pressure head and a static pressure head to explain the spiral centrifugal pump, the law of energy transfer and transformation;2) study the pressure field of the spiral centrifugal pump and The distribution law of the speed field along the impeller, and the flange line and the hub line of the spiral centrifugal pump impeller are segmented, the energy of the spiral centrifugal pump is analyzed from the dynamic pressure head and the static pressure head, the conversion capacity of the spiral centrifugal pump along the impeller is analyzed, and the performance and the design theory of the spiral centrifugal pump are improved. Based on the theoretical analysis and the numerical calculation, the overall conversion performance of the energy of the spiral centrifugal pump is discussed, and the velocity of the flow field in the water and the solid-liquid two-phase flow is discussed in detail. The numerical simulation results of the flow of the whole flow channel are qualitatively and quantitatively analyzed, such as the degree, the pressure, the flow line, the hydraulic loss, etc. The main conclusions are as follows:1) The overall change of the relative speed is from small to small along the angle of the package. a slight decrease in a very small section, which is in the course of a certain period the invention reduces the efficiency of the spiral centrifugal pump, and 2) during the work of the spiral centrifugal pump impeller, the static pressure head and the dynamic pressure head of the spiral section At the maximum radius, the head of the static pressure head is the largest, the head of the spiral centrifugal pump is mainly generated by the spiral section, and the spiral section of the front part of the impeller plays a role of multi-stage adding energy. It is proved that the spiral section plays a key role in the work of the impeller in that case of the turbulent movement of the two-phase flow, in the case of the turbulent motion of the two-phase flow, due to the difference of the force field, the spiral propeller of the spiral centrifugal pump Under the action of the heart, the solid-liquid two-phase is moved at different speed. The energy conversion of the spiral centrifugal pump is mainly the energy change of the liquid under the simulated working condition, and the solid phase is in the liquid.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH311
本文编号：2495065
[Abstract]:The spiral centrifugal pump is a solid-liquid two-phase flow pump with special structure and efficiency, which is superior to the centrifugal type impurity pump and the swirl type impurity pump, and the spiral pump and the centrifugal pump are integrated into a whole, and the unique structure of the spiral centrifugal pump can fully play the advantages of both. Compared with other impurity pumps, the spiral centrifugal pump has the advantages of good non-blocking property, suction performance, regulating performance and anti-cavitation performance, and has the advantages of no overload, high efficiency and wide effective area. For a long time, the improvement of the energy utilization rate of the pump products has been a problem in the pump industry, and how to achieve higher efficiency under the same working conditions is the most concerned question of the pump industry. The efficiency of the spiral centrifugal pump is generally lower with respect to the centrifugal pump, that is, the efficiency of the spiral centrifugal pump still has a large lift The impeller, as an important component of the spiral centrifugal pump, can even be said to be the heart of the spiral centrifugal pump, the blade shape of the impeller has a decisive influence on the hydrodynamic characteristics of the impeller, and the effect of the pump is determined to a great extent. In the case of the spiral centrifugal pump for solid-liquid two-phase flow media, because of the complexity of the water flow state in the impeller, the one-way flow theory and the empirical design method are difficult to meet the need of designing an excellent hydraulic performance impeller, and the motion state of the solid-liquid two-phase medium in the impeller of the spiral centrifugal pump it is to be seen that the impeller causes the fluid to complete the transition from the axial to the radial direction, the axial velocity of the liquid stream being large, the radial velocity being the opposite, which requires that the pitch of the blade be changed from the inlet to the outlet from large to small Thus, the mechanism of the energy conversion of the impeller and the flow and the working condition of each part of the impeller can be explored, and the reasonable design of the impeller can be provided with more effective improvement. In this paper, the main research of the mechanism of the energy conversion of the spiral centrifugal pump is given in this paper. The results are as follows: On the one hand, the fluid flow in the fluid machine is theoretically analyzed, the Euler equation is applied, and the energy of the fluid in the impeller is divided into dynamic pressure head and static pressure head. The pressure head is used to deal with, and the numerical simulation is used to study the internal flow of the spiral centrifugal pump and the work ability of each section of the impeller. On the other hand, the pressure distribution, the velocity distribution and the solid structure of the inner flow field under the action of the impeller are analyzed by numerical simulation. In this paper, the energy conversion mechanism of the spiral centrifugal pump and its superior anti-clogging and non-destructive characteristics are obtained. The internal relation of this article. The innovation of the invention is mainly as follows:1) the Euler equation of a fluid machine is applied, the energy converted by the impeller is divided into a dynamic pressure head and a static pressure head to explain the spiral centrifugal pump, the law of energy transfer and transformation;2) study the pressure field of the spiral centrifugal pump and The distribution law of the speed field along the impeller, and the flange line and the hub line of the spiral centrifugal pump impeller are segmented, the energy of the spiral centrifugal pump is analyzed from the dynamic pressure head and the static pressure head, the conversion capacity of the spiral centrifugal pump along the impeller is analyzed, and the performance and the design theory of the spiral centrifugal pump are improved. Based on the theoretical analysis and the numerical calculation, the overall conversion performance of the energy of the spiral centrifugal pump is discussed, and the velocity of the flow field in the water and the solid-liquid two-phase flow is discussed in detail. The numerical simulation results of the flow of the whole flow channel are qualitatively and quantitatively analyzed, such as the degree, the pressure, the flow line, the hydraulic loss, etc. The main conclusions are as follows:1) The overall change of the relative speed is from small to small along the angle of the package. a slight decrease in a very small section, which is in the course of a certain period the invention reduces the efficiency of the spiral centrifugal pump, and 2) during the work of the spiral centrifugal pump impeller, the static pressure head and the dynamic pressure head of the spiral section At the maximum radius, the head of the static pressure head is the largest, the head of the spiral centrifugal pump is mainly generated by the spiral section, and the spiral section of the front part of the impeller plays a role of multi-stage adding energy. It is proved that the spiral section plays a key role in the work of the impeller in that case of the turbulent movement of the two-phase flow, in the case of the turbulent motion of the two-phase flow, due to the difference of the force field, the spiral propeller of the spiral centrifugal pump Under the action of the heart, the solid-liquid two-phase is moved at different speed. The energy conversion of the spiral centrifugal pump is mainly the energy change of the liquid under the simulated working condition, and the solid phase is in the liquid.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH311
【引证文献】
相关硕士学位论文 前2条
1 高宏;变转速工况下螺旋离心泵相似特性研究[D];兰州理工大学;2013年
2 苏清苗;蜡式温控阀控温机理及内部流动特性研究[D];兰州理工大学;2013年
本文编号：2495065
本文链接：https://www.wllwen.com/kejilunwen/jixiegongcheng/2495065.html
