本文關(guān)鍵詞： 單流道離心泵 水力設計 非定常特性 滑移系數(shù) 同步測試　出處：《江蘇大學》2015年博士論文　論文類型：學位論文

【摘要】：本文的研究是在國家科技支撐計劃(2013BAK06B02)的資助下開展的。隨著建設生態(tài)中國和加快環(huán)境治理的發(fā)展,單流道離心泵在污水污物和無堵塞輸送方面得到了廣泛的應用,但在能耗高和運行平穩(wěn)性差方面還有很多難題需要研究。為了提高單流道泵運行的效率和穩(wěn)定性,進一步豐富和發(fā)展單流道泵的水力設計方法,本文采用試驗測試、數(shù)值計算和理論分析相結(jié)合的方法對單流道泵的非定常運行特性和水力設計進行了深入研究。主要工作和創(chuàng)造性成果有：1.搭建了單流道離心泵能量性能和非定常特性的同步測試臺,開展了能量性能、揚程脈動、壓力脈動和徑向力的試驗研究。試驗發(fā)現(xiàn)：(1)單流道泵的揚程具有強烈的非定常特性,設計工況下?lián)P程脈動量是平均揚程的26.6%；(2)當泵的工況由0.6Qd增大到1.4Qd時,揚程極小值出現(xiàn)的葉輪旋轉(zhuǎn)角度由43°逐漸增大到60°,揚程極大值出現(xiàn)的葉輪旋轉(zhuǎn)角度由280°逐漸減小至268°；(3)當葉片出口邊剛好通過隔舌位置時,蝸殼第8斷面處的壓力脈動出現(xiàn)峰值,隨著葉輪的旋轉(zhuǎn),從蝸殼的第8斷面到第1斷面逐漸出現(xiàn)壓力脈動峰值；(4)時均徑向力隨流量的增大呈先減小后增大的趨勢,最小值出現(xiàn)在最優(yōu)工況,當泵的工況由0.4Qd增大到1.4Qd時,時均徑向力方向由蝸殼隔舌下游265°逐漸增大至隔舌下游272°。2.基于試驗對單流道泵復雜內(nèi)流CFD計算方法進行了驗證,并對葉輪內(nèi)的流動特性進行了分析。(1)單流道離心泵內(nèi)流數(shù)值模擬應采用非定常計算方法求解,其中小流量工況的內(nèi)流CFD計算可采用SST k-ω模型,其它工況可采用k-ε模型；(2)當葉片出口邊與蝸殼隔舌相對位置由0°旋轉(zhuǎn)到325°時,葉輪出口處高壓區(qū)的周向位置由40°增大至330°,高壓區(qū)始終位于葉片出口邊的下游位置；(3)小流量工況時,葉片進口邊下游壓力面流道內(nèi)出現(xiàn)較嚴重的流動分離和回流現(xiàn)象。3.針對單流道離心泵強烈的非定常特性,基于Backstrom的單相對渦假設對Busemann滑移系數(shù)理論解中的h0和cm進行了數(shù)學建模,首次建立了單流道葉輪全流量范圍內(nèi)滑移系數(shù)的求解公式,并用一臺比轉(zhuǎn)速ns=140的單流道離心泵對滑移系數(shù)進行了試驗驗證。結(jié)果表明：(1)建立的數(shù)學模型與理論解具有較好的一致性,其中h0的數(shù)學模型在β2B≥40°時比Wiesner解的精度更高；(2)全流量范圍內(nèi)滑移系數(shù)的計算結(jié)果與試驗值基本一致,最大偏差僅為5.05%。4.應用本文建立的單流道葉輪全流量滑移系數(shù)求解公式和能量損失模型,提出了一種單流道離心泵能量性能預測模型,并用2臺單流道泵進行了試驗驗證。結(jié)果表明該模型能夠較為準確地預測單流道泵揚程、功率和效率等性能,最大偏差在6%以內(nèi)。5.改進了單流道葉輪的水力設計方法。基于建立的能量性能預測模型,根據(jù)輸送顆粒最大直徑、設計工況揚程和電機最大配套功率的約束條件,以機組效率最高為設計目標,對單流道葉輪主要幾何參數(shù)的計算方法進行了改進；首次針對“薄壁型”單流道葉輪提出了一種全單調(diào)的葉片型線函數(shù),針對“厚壁型”單流道葉輪提出了一種流道中線方程,對單流道葉輪的繪型方法進行了改進。國內(nèi)外同類產(chǎn)品的性能對比表明,采用改進水力設計方法兩組葉輪的泵效率已達到國際先進水平。6.基于試驗和CFD研究了葉片型線函數(shù)、葉片出口平均安放角β2B和葉片包角εsb對能量性能的影響。結(jié)果表明(1)采用全單調(diào)型線函數(shù)、減小β2B以及減小葉片出口邊吸力側(cè)安放角β2SB可以降低葉輪出口混合損失和葉輪內(nèi)的水力損失,εsb對葉輪出口混合損失的影響較小,但增大εsb能夠降低葉輪內(nèi)的水力損失；(2)隨著β2B的減小,揚程流量曲線呈陡降趨勢,功率流量曲線呈現(xiàn)無過載特性；(3)隨著β2B由80增大到250,泵的揚程和功率逐漸增大,效率先增大后減小,效率最大增加了7個百分點；隨著β2SB由24°增大到42°,揚程和功率逐漸增大,效率逐漸減小,效率最大減小了1.8個百分點；隨著εsb由290°增大到3900,功率逐漸減小,揚程和效率逐漸增大,效率最大增加了7.79個百分點。7.基于試驗測量了葉片出口安放角和葉片包角對揚程脈動、壓力脈動和徑向力的影響。結(jié)果表明：(1)揚程極大值的時域分布以及徑向力的方向主要受葉片出口邊壓力側(cè)安放角β2BPB的影響,受β2BB和εsb的影響較小,隨著β2PB由8°增大到25°,揚程極大值在時域上逐漸滯后,徑向力方向指向的周向角度逐漸減�。�(2)隨著β2B由8°增大到25°、β2SB由24°增大到42°以及εsb由390°減小到290°,泵的揚程脈動、壓力脈動和徑向力逐漸增大,幾何參數(shù)對揚程脈動和壓力脈動影響程度從大到小依次為β2Bβ2SBεsb,對徑向力影響程度從大到小依次為β2SBβ2Bεsb；(3)在保證單流道泵能量性能和顆粒通過性能的情況下,減小β2B和β2SB以及增大εsb有利于改善泵的非定常特性,提高單流道泵的運行穩(wěn)定性。
[Abstract]:The research of this paper is in the national science and technology support program (2013BAK06B02) to carry out funding. With the development of the construction of ecological environment and accelerate the China governance, single channel of centrifugal pump has been widely used in sewage and non blocking conveyance, but in high energy consumption and stable operation of the poor there is still a lot of problems need to be studied. In order to improve the efficiency and stability of single channel pump operation, further enrich and develop the hydraulic design method of single channel pump, test using this method, numerical calculation and theoretical analysis of a combination of single channel pump unsteady operation characteristics and hydraulic design were studied. The main work and achievements are as follows: 1. set the energy performance of centrifugal pump of single channel and non synchronous test bench steady characteristics, to carry out energy performance, lift pulsation, experimental study on pressure fluctuation and radial force test found. : (1) single channel pump head with unsteady characteristics of strong lift, pulsating quantity under design conditions is the average lift 26.6%; (2) when the pump condition increased from 0.6Qd to 1.4Qd, the minimum value of the rotation of the impeller head angle from 43 degrees to 60 degrees increased gradually, the maximum lift impeller the rotation angle of 280 degrees by gradually reduced to 268 degrees; (3) when the blade outlet edge just through the tongue position, at the peak of the eighth volute cross pressure pulsation, along with the rotation of the impeller, volute from eighth to first section section the gradual emergence of pressure fluctuation peak; (4) both with radial force the increase of flow rate first decreased and then increased, the minimum value appeared in the optimal condition, when the pump condition increased from 0.4Qd to 1.4Qd, when the direction of radial force by the volute tongue downstream 265 degrees increased gradually to 272 DEG.2. downstream of the tongue test on single channel pump flow complex internal flow based on CFD The calculation method was verified, and the flow characteristics of the impeller were analyzed. (1) should be used for calculation of unsteady flow numerical simulation method for single channel in the centrifugal pump, the small flow condition in CFD flow calculation can be used SST k- turbulence model, other conditions can be using the k- model (2); when the blade outlet edge and volute tongue relative position by rotating 0 degrees to 325 degrees, the impeller outlet pressure area of the circumferential position increased from 40 degrees to 330 degrees, high pressure area has always been at the downstream position of blade outlet edge; (3) at small flow condition, the downstream pressure surface of blade inlet edge flow appeared serious flow separation and recirculation phenomenon of.3. according to the unsteady characteristics of single channel pump strong, Backstrom phase of vortex assumption of Busemann slip factor theoretical solution in H0 and cm were studied based on mathematical modeling, first established the single channel impeller full flow range slip Formula of coefficient, and use a single channel than the rotation speed of the centrifugal pump ns=140 on slip coefficient were tested. The results showed that: (1) the establishment of mathematical model and theoretical solutions have good consistency, the mathematical model of H0 in beta 2B is not less than 40 DEG C than Wiesner and the precision is higher; (2) the results of the full flow range of slip coefficient is basically consistent with the experimental values, the maximum deviation is only 5.05%.4. single channel impeller based full flow slip coefficient formula and energy loss model, put forward the energy performance of a single pre runner centrifugal pump test model, and 2 sets of single channel pump experiment results show that the model can accurately predict the single channel pump head, power and efficiency, the maximum deviation of the improved hydraulic design method of single channel impeller within 6%.5.. The energy performance of the pre established measurement model based on According to the maximum diameter of particle, conveying, constraint conditions and design conditions lift motor maximum power matching, to set the highest efficiency as the design goal, the calculation method of main geometric parameters of single channel impeller was improved; first proposed a blade type line full monotonic function for thin-walled single channel impeller ", for" the thick wall type single channel presents a channel midline equation, the drawing method of single channel impeller was improved. Comparison show that the performance of similar products at home and abroad, the pump efficiency improvement of hydraulic design method of impeller two group has reached the international advanced level of.6. test and CFD were studied based on the blade type line function. The average effect of blade outlet installing angle beta 2B and blade angle epsilon sb on energy performance. The results show that (1) the monotone line function, reduce beta 2B and reduce the blade outlet edge suction Ce Anfang Angle of 2SB can reduce the hydraulic loss in the impeller and the impeller outlet mixing loss, epsilon sb has little effect on the impeller mixing loss, but the increase of epsilon sb can reduce the hydraulic loss in the impeller; (2) with the decrease of beta 2B, head flow curve is steep drop trend, power flow curve has non overload characteristics; (3) with beta 2B increased from 80 to 250, and the lift of the pump power increases, the efficiency increases first and then decreases, the maximum efficiency increased by 7 percentage points; with beta 2SB increased from 24 degrees to 42 degrees, the lift and power increased, efficiency decreased gradually, maximum efficiency decreases by 1.8 percentage points; with epsilon sb increased to 3900 by 290 degrees, power decreases gradually, the head and the efficiency increased gradually, the maximum efficiency increased by 7.79 percentage points of.7. measuring the outlet blade angle and blade angle on the head pulsation based on the influence of pressure fluctuation and radial force. 琛ㄦ槑錛，

本文編號：1513207