本文關鍵詞：離心泵葉輪特殊切割方法的研究與探討　出處：《浙江工業(yè)大學》2012年碩士論文　論文類型：學位論文

  更多相關文章： 離心泵 葉輪 切割方法 性能曲線 數(shù)值模擬 試驗研究

【摘要】：低比轉速離心泵的H-Q性能曲線比較平坦,容易產生駝峰。駝峰特性曲線的關死點揚程低于泵的最大揚程值,在運轉中不穩(wěn)定,特別是在小流量工況,泵和管路系統(tǒng)內可能會產生振動和噪聲,具有較大的危害性。因此尋找簡單易行的消除泵特性曲線駝峰的方法具有重要的意義。 斜切葉輪外徑、葉片出口邊三角形切割等一些特殊的葉輪切割方法可以消除離心泵特性曲線駝峰,但這些切割方法的應用大多依賴于經驗,切割尺寸的選擇缺少理論依據(jù)。為此,本文在這兩種特殊切割方法的基礎上,提出一種新型的半圓形切割方法,以這三種葉輪特殊切割方法為研究對象,采用CFD數(shù)值模擬方法,對葉輪及蝸殼內部流動狀態(tài)進行計算和分析,同時對不同的葉輪切割方法及其切割尺寸與離心泵性能曲線駝峰之間的關系進行了理論分析,并制造樣機對模擬結果進行試驗驗證。最終得到了幾種優(yōu)秀的切割模型,為離心泵葉輪特殊切割方法的使用提供了科學依據(jù)。 本文的主要研究工作包括： (1)查閱了大量國內外研究離心泵葉輪切割的文獻,綜述了葉輪切割定律以及葉輪切割方法的研究現(xiàn)狀,為提出新型葉輪切割方法提供理論依據(jù)和前期準備工作。 (2)系統(tǒng)地介紹了利用CFD數(shù)值模擬計算離心泵流場分布的研究方法,包括離心泵的Pro/E三維建模方法、Gambit網格生成方法、Fluent求解器參數(shù)定義和離散化方法的選擇。并利用該方法對IS80-50-250型單級單吸清水離心泵內流場進行CFD數(shù)值模擬。 (3)對三角形切割、半圓形切割和斜切葉輪外徑方法進行詳細的描述,制定多組研究方案對三種葉輪特殊切割方法進行研究。介紹了基于CFD數(shù)值模擬的離心泵性能曲線預測方法,并利用該方法預測模型泵及各切割方案的離心泵性能曲線。比較各種切割方案對性能曲線的改善情況,確定三角形切割、半圓形切割和斜切葉輪外徑方法的最佳切割尺寸。 (4)根據(jù)數(shù)值模擬結果,利用Fluent后處理工具,分析離心泵的內部流動規(guī)律。結果表明,在小流量工況時,離心泵葉輪出口以及蝸殼內部存在較大的壓力梯度,速度分布不均勻,由此產生的混合沖擊損失導致關死點揚程降低,并使泵特性曲線產生駝峰。對葉輪葉片出口邊進行特殊形狀的切割可以改善小流量工況泵內部湍流流動狀態(tài),從而消除泵特性曲線駝峰。 (5)對模型泵及三角形最佳切割方案進行離心泵性能試驗,驗證數(shù)值模擬結果的準確性。試驗表明揚程預測誤差為-3.02%～1.69%,效率預測誤差為1.46%～4.72%,最大誤低于5%,模擬結果和試驗結果符合良好。
[Abstract]:The H-Q performance curve of the centrifugal pump with low specific speed is flat and easy to produce hump. The dead point head of the hump characteristic curve is lower than the maximum lift value of the pump and is unstable in operation especially in the small flow condition. The vibration and noise may occur in the pump and pipeline system, which is harmful. Therefore, it is of great significance to find a simple and feasible method to eliminate the hump of the pump characteristic curve. Some special impeller cutting methods, such as external diameter of oblique impeller and triangular cutting of blade outlet edge, can eliminate the hump of characteristic curve of centrifugal pump, but the application of these cutting methods mostly depends on experience. The selection of cutting size is lack of theoretical basis. Therefore, based on the two special cutting methods, this paper proposes a new semi-circular cutting method, taking these three special impeller cutting methods as the research object. The flow state of impeller and volute is calculated and analyzed by CFD numerical simulation method. At the same time, the relationship between different impeller cutting methods and the relationship between the cutting size and the hump of centrifugal pump performance curve is analyzed theoretically. Finally, several excellent cutting models are obtained, which provide a scientific basis for the use of special cutting methods for centrifugal pump impeller. The main research work of this paper includes: 1) A large number of literatures on centrifugal pump impeller cutting are reviewed, and the current research status of impeller cutting law and impeller cutting method is summarized. It provides theoretical basis and preparatory work for the new impeller cutting method. This paper introduces the research method of calculating flow field distribution of centrifugal pump by CFD numerical simulation, including Pro/E 3D modeling method of centrifugal pump and Gambit mesh generation method. The parameter definition of Fluent solver and the choice of discretization method are used to simulate the flow field in IS80-50-250 single-stage single-suction centrifugal pump with CFD. 3) the methods of triangle cutting, semicircle cutting and oblique cutting impeller outer diameter are described in detail. Three kinds of special impeller cutting methods are studied in this paper. The prediction method of centrifugal pump performance curve based on CFD numerical simulation is introduced. This method is used to predict the performance curve of the model pump and the centrifugal pump of each cutting scheme. The triangle cutting is determined by comparing the improvement of the performance curve of various cutting schemes. Optimum cutting size of semicircle and oblique cutting impeller outer diameter method. 4) according to the numerical simulation results, the internal flow law of centrifugal pump is analyzed by using Fluent post-processing tool. The results show that the flow rate is small in the case of small flow rate. There is a large pressure gradient and uneven velocity distribution in the outlet of centrifugal pump impeller as well as inside the volute. The resulting mixed impact loss results in the decrease of closed dead point head. The special shape cutting of the impeller blade outlet edge can improve the turbulent flow state of the pump under small flow conditions, thus eliminating the hump of the pump characteristic curve. The model pump and triangle optimum cutting scheme are tested to verify the accuracy of numerical simulation results. The results show that the error of lift prediction is -3.02% and 1.69%. The efficiency prediction error is 1.46 and 4.72, and the maximum error is less than 5. The simulation results are in good agreement with the test results.
【學位授予單位】：浙江工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH311

【參考文獻】

相關期刊論文 前10條

1 于建基;;離心泵葉輪變徑實踐[J];甘肅科技;2010年22期

2 陳敏;;論述離心泵葉輪切割方法[J];廣東科技;2010年10期

3 吳仁榮;林志強;;關于雙吸離心泵切割規(guī)律的研究[J];機電設備;2010年05期

4 孟繁華,郝連儉,郝旭林;離心泵葉輪外徑切割方法的探討[J];機械管理開發(fā);2002年03期

5 曹樹良,王萬鵬,祝寶山;離心泵壓水室內部流動數(shù)值模擬[J];江蘇大學學報(自然科學版);2004年03期

6 張淑佳;李賢華;朱保林;胡清波;;k-ε渦粘湍流模型用于離心泵數(shù)值模擬的適用性[J];機械工程學報;2009年04期

7 梁永儀,張挺,孫明光;間隔式切割葉片對離心泵性能的影響[J];流體工程;1993年10期

8 王秀勇;王燦星;;基于數(shù)值模擬的離心泵性能預測[J];流體機械;2007年10期

9 牟介剛;李思;鄭水華;邵云峰;趙永攀;蘇苗印;;離心泵葉片出口邊三角切割方法的研究與探討[J];流體機械;2010年02期

10 顧建明，陸明琦;離心泵葉輪切割對性能的影響[J];流體機械;1994年05期

相關博士學位論文 前1條

1 牟介剛;離心泵現(xiàn)代設計方法研究和工程實現(xiàn)[D];浙江大學;2005年

相關碩士學位論文 前1條

1 金雋;網格生成算法研究和軟件實現(xiàn)[D];復旦大學;2008年

，

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