【摘要】：單級雙吸中開式離心泵廣泛應用于水利灌溉工程、城市給排水、工業(yè)循環(huán)水、跨流域調水等領域，是一種重要的水力機械，其運行特性對泵站工程造價、運行及維護等具有重要影響。對雙吸泵運行特性進行深入研究，不僅具有理論意義，而具有重要工程實用價值。由于雙吸泵一般流量較大，揚程較高，所需配用功率大，是一種耗能較大的設備。因此，使用單位對雙吸泵的效率有較高的要求，而國內目前所生產(chǎn)的雙吸泵效率普遍不太高，尤其是一些低比轉速的雙吸泵，其效率都比較低，有的泵效率達不到70%。所以提高雙吸泵的效率，節(jié)能降耗尤為重要。隨著國家在今后對水利建設方面投資力度的加大，雙吸泵的使用量將進一步的增加，因此對雙吸泵性能的改進，對于泵產(chǎn)品節(jié)能降耗具有重要意義。 近年來，計算流體力學（CFD）技術已經(jīng)廣泛并成功的運用于泵的設計和分析計算中，在科研和工程領域有著廣泛的應用。為了準確了解泵內過流部件對其性能的影響，本文基于泵設計理論，借助CFD軟件對雙吸泵過流部件進行了研究分析計算。 對于雙吸泵的主要過流部件壓水室（蝸殼）和半螺旋吸入室，本文主要針對蝸殼隔舌和半螺旋吸入室隔舌（鼻端）進行了分析研究。通過CFD軟件，對蝸殼隔舌在不同的隔舌安放角時，對其不同工況下進行了定常分析計算；并對泵在不同隔舌安放角時，在設計工況點進行了非定常數(shù)值模擬分析；對不同的吸入室隔舌，在不同工況下進行了定常分析。 通過對數(shù)值計算結果的分析發(fā)現(xiàn)，當蝸殼的隔舌使用不同隔舌安放角時，泵的性能均有變化，尤其在偏大流量工況，隔舌安放角對泵的影響較明顯，其影響主要由于隔舌安放角變化引起的隔舌間隙的改變對泵的影響，另外還有蝸殼喉部面積的變化，隔舌頂部的沖擊損失對泵性能的影響相對較小；對于吸入室隔舌，隔舌距離泵軸的距離改變，對泵的性能也有一定的影響，在大流量工況影響較明顯，，其影響主要由于隔舌對液流的作用及吸入室內速度不同部分液流的相互作用。對于本文使用的模型泵，蝸殼內隔舌處隔舌安放角的大小和吸入室內隔舌距離泵軸的距離大小，這些參數(shù)均有一個較好的值。吸入室隔舌離泵軸的距離大小應根據(jù)不同的泵來確定其值。 本文的分析結果表明，對雙吸泵內過流部件的深入研究，有利于泵性能的提高，對泵產(chǎn)品的節(jié)能降耗和市場競爭力的提升有一定的幫助。
[Abstract]:Single stage and double suction open centrifugal pump is widely used in water conservancy and irrigation engineering, urban water supply and drainage, industrial circulating water, trans-basin water transfer and so on. Operation and maintenance have important impact. It is not only of theoretical significance, but also of great practical value to study the operating characteristics of double suction pumps. The double suction pump is a kind of energy consuming equipment because of its high flow rate, high head and high power consumption. Therefore, the efficiency of the double suction pump is very high, but the efficiency of the double suction pump produced in our country is generally not very high, especially for some low specific rotational speed double suction pump, its efficiency is relatively low, some pump efficiency is less than 70. So it is very important to improve the efficiency of double suction pump and save energy and reduce consumption. With the increase of national investment in water conservancy construction in the future, the use of double suction pump will be further increased, so the improvement of double suction pump performance is of great significance for energy saving and consumption reduction of pump products. In recent years, computational fluid dynamics (CFD) technology has been widely used in pump design, analysis and calculation, and has been widely used in scientific research and engineering fields. In order to accurately understand the influence of the flow passing parts in the pump on its performance, based on the pump design theory and with the help of CFD software, this paper studies and calculates the flow passing parts of the double suction pump. The pressure chamber (volute) and semi-helical suction chamber are the main parts of double suction pump. This paper mainly analyzes and studies the diaphragm (nasal end) of volute septum and semi-helical suction chamber. Through the software of CFD, the unsteady analysis and calculation of the volute diaphragm tongue under different working conditions are carried out, and the unsteady numerical simulation analysis is carried out at the design working condition when the pump is placed at different angle of diaphragm tongue. A steady analysis of different suction chamber septum was carried out under different working conditions. Through the analysis of the numerical results, it is found that the performance of the pump varies with the use of different tongue separation angles in the volute, especially in the condition of large flow rate, the influence of the angle of setting the tongue on the pump is obvious. The influence is mainly due to the change of the gap between the tongue and the pump caused by the change of the angle of setting the tongue, and the change of the throat area of the volute. The impact loss at the top of the diaphragm has relatively little effect on the performance of the pump. The change of the distance between the pump shaft and the tongue diaphragm has a certain effect on the pump performance, which is more obvious in the large flow condition, mainly due to the effect of the tongue separation on the liquid flow and the interaction of the different parts of the fluid flow in the suction chamber. For the model pump used in this paper, these parameters have a good value, such as the angle of the tongue septum in the volute and the distance between the suction chamber and the pump shaft. The distance between the suction chamber and the pump shaft should be determined according to the pump. The results of this paper show that the deep study of the overflowing parts in the double suction pump is beneficial to the improvement of pump performance and to the improvement of energy saving and consumption reduction of pump products as well as the promotion of market competitiveness.
【學位授予單位】：蘭州理工大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH311

【引證文獻】

相關期刊論文 前1條

1 肖若富;王娜;楊魏;姚志峰;王福軍;;復合葉輪改善雙吸式離心泵空化性能研究[J];農(nóng)業(yè)機械學報;2013年09期

本文編號：2221899