【摘要】：螺旋離心泵是一種具有特殊結(jié)構(gòu)與效率優(yōu)于離心式雜質(zhì)泵和旋流式雜質(zhì)泵的固液兩相流泵，將螺旋泵與離心泵融合為一體，其獨(dú)特的結(jié)構(gòu)可將兩者的優(yōu)勢(shì)充分發(fā)揮。相比其他雜質(zhì)泵，螺旋離心泵具有良好的無堵塞性、吸入性能、調(diào)節(jié)性能和抗汽蝕性能，并具有無過載、效率高及高效區(qū)寬等優(yōu)點(diǎn)。 長(zhǎng)久以來，泵類產(chǎn)品能量利用率的提高問題，一直困擾著泵行業(yè)工作者，如何在同等工況下，獲得較高的效率，是泵行業(yè)工作者最為關(guān)心的問題。相對(duì)于離心泵，螺旋離心泵的效率普遍較低，也就是說螺旋離心泵的效率仍具有較大的提升空間。而葉輪作為螺旋離心泵的重要元件，，甚至可以說是螺旋離心泵的心臟，葉輪的葉片形狀對(duì)葉輪的水動(dòng)力特性具有決定性的影響，在很大程度上決定著該泵的效率。對(duì)于輸送固液兩相流介質(zhì)的螺旋離心泵來說，由于其葉輪內(nèi)水流狀態(tài)的復(fù)雜性，一元流動(dòng)理論和經(jīng)驗(yàn)設(shè)計(jì)方法難以滿足設(shè)計(jì)優(yōu)良水力性能葉輪的需要；從固液兩相介質(zhì)在螺旋離心泵葉輪內(nèi)的運(yùn)動(dòng)狀態(tài)來看，其葉輪使得流體完成從軸向至徑向的過渡，液流的軸向速度由大變小，徑向速度則相反，這就要求葉片的螺距從進(jìn)口至出口要做由大到小的平滑變化。因此，探究葉輪能量轉(zhuǎn)換機(jī)理和葉輪各個(gè)部分內(nèi)的流動(dòng)與做功情況，可以為葉輪的合理設(shè)計(jì)提供更有效地改進(jìn)方案。 本文針對(duì)螺旋離心泵能量轉(zhuǎn)換機(jī)理的主要研究，內(nèi)容如下： 一方面從理論上分析了流體機(jī)械內(nèi)部的流體流動(dòng)情況，應(yīng)用歐拉方程，將流體在葉輪中的能量分為動(dòng)壓頭和靜壓頭來處理，為數(shù)值模擬來研究螺旋離心泵內(nèi)部流動(dòng)和葉輪各段的做功能力提供了理論基礎(chǔ)；另一方面通過數(shù)值模擬，分析了葉輪作用下內(nèi)流場(chǎng)的壓力分布、速度分布以及固相濃度分布，由此得出了螺旋離心泵能量轉(zhuǎn)換機(jī)理以及與其優(yōu)越的抗堵塞特性和無損特性等產(chǎn)生的內(nèi)在聯(lián)系。 本文的創(chuàng)新性主要有： 1）應(yīng)用流體機(jī)械的歐拉方程，將葉輪轉(zhuǎn)換的能量分為動(dòng)壓頭和靜壓頭來解釋螺旋離心泵的能量傳遞和轉(zhuǎn)化規(guī)律； 2）研究螺旋離心泵的壓力場(chǎng)和速度場(chǎng)沿葉輪的分布規(guī)律，并將螺旋離心泵葉輪的輪緣線和輪轂線分段，分別從動(dòng)壓頭和靜壓頭變化分析螺旋離心泵的能量沿葉輪包角的轉(zhuǎn)換能力，對(duì)于螺旋離心泵的性能提高和設(shè)計(jì)理論的完善具有很好的指導(dǎo)意義。 通過理論分析和數(shù)值計(jì)算，從螺旋離心泵能量的總體轉(zhuǎn)換性能，具體探討了設(shè)計(jì)工況下，介質(zhì)分別為清水和固液兩相流的沙水時(shí)流場(chǎng)的速度、壓力、流線、水力損失等，對(duì)其全流道流動(dòng)的數(shù)值模擬結(jié)果進(jìn)行了定性與定量對(duì)比分析，獲得主要結(jié)論如下： 1)沿包角的由小到大，相對(duì)速度的總體變化局勢(shì)是逐漸增大的，在很小的區(qū)段略有降低，這在一定的程度上降低了螺旋離心泵效率的提高； 2)在螺旋離心泵葉輪做功過程中，螺旋段的靜壓頭和動(dòng)壓頭的整體是增加的，而在離心段則不一定。在最大半徑處，靜壓頭達(dá)到了最大，說明螺旋離心泵的揚(yáng)程主要是螺旋段產(chǎn)生的，葉輪前部螺旋段起到了多級(jí)加能的作用，這也驗(yàn)證了螺旋段在葉輪做功中起著主要作用； 3)在兩相流湍流運(yùn)動(dòng)的情況下，由于力場(chǎng)的不同，在螺旋離心泵葉輪螺旋推進(jìn)和離心作用下，使得固液兩相以不同的速度運(yùn)動(dòng)。螺旋離心泵在模擬工況下能量轉(zhuǎn)換主要是液體的能量變化，固相是在液體的裹協(xié)下運(yùn)動(dòng)，固體能量是通過液體間接進(jìn)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.
【學(xué)位授予單位】：蘭州理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類號(hào)】：TH311

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 高宏;變轉(zhuǎn)速工況下螺旋離心泵相似特性研究[D];蘭州理工大學(xué);2013年

2 蘇清苗;蠟式溫控閥控溫機(jī)理及內(nèi)部流動(dòng)特性研究[D];蘭州理工大學(xué);2013年

本文編號(hào)：2495065