夏臣智,成 立,蔣紅櫻,辛 健
?
潛水貫流泵裝置過流部件水力性能分析與優(yōu)化
夏臣智1,成 立1,蔣紅櫻2,辛 健3
(1. 揚(yáng)州大學(xué)水利與能源動(dòng)力工程學(xué)院,揚(yáng)州 225127; 2. 江蘇省水利工程科技咨詢有限公司,南京 210029; 3. 江蘇亞太泵閥有限公司,泰州 225400)
為研究潛水貫流泵裝置過流部件的水力性能,該文采用CFD方法對(duì)潛水貫流泵裝置進(jìn)行數(shù)值計(jì)算,分析了不同過流部件形式對(duì)泵裝置內(nèi)水力性能的影響,并對(duì)計(jì)算結(jié)果進(jìn)行試驗(yàn)驗(yàn)證。結(jié)果表明:潛水貫流泵裝置燈泡體支撐片的數(shù)量會(huì)影響導(dǎo)葉與支撐片之間的水流流態(tài),支撐片的數(shù)量應(yīng)與導(dǎo)葉片數(shù)一致。潛水貫流泵裝置宜采用橢球體的燈泡體尾部形式,能避免回流、脫流等不良流態(tài)的產(chǎn)生。采用流線形進(jìn)線孔,并且將進(jìn)線孔與支撐片結(jié)合在一起,能改善出水燈泡體的流態(tài),提高裝置效率。在閘門槽間的進(jìn)水流道過渡形式宜采用漸縮方管式。優(yōu)化后泵裝置在最優(yōu)工況點(diǎn)的效率提高2.5%,達(dá)到78.0%。在最高效率點(diǎn),數(shù)值計(jì)算預(yù)測(cè)揚(yáng)程和流量的不確定度均小于1%,試驗(yàn)與數(shù)值計(jì)算結(jié)果吻合較好。該研究可為潛水貫流泵裝置在實(shí)際工程中推廣應(yīng)用提供參考。
泵;計(jì)算機(jī)仿真;優(yōu)化;潛水貫流泵;過流部件;模型試驗(yàn)
貫流泵是一種用于低揚(yáng)程、大流量泵站的經(jīng)濟(jì)型泵,具有水力損失小、裝置效率高等特點(diǎn)。南水北調(diào)東線一期工程新建泵站中有7座選用貫流泵[1-4]。潛水貫流泵是一種采用潛水電機(jī)作為燈泡體的貫流泵型,與其他貫流泵型相比,具有優(yōu)良的水力性能、緊湊的結(jié)構(gòu)形式、良好的抗噪性和低廉的運(yùn)行費(fèi)用等特點(diǎn),在城市雨水集放、防洪排澇和灌溉方面有良好的應(yīng)用前景[5-6]。
潛水貫流泵裝置常被用于低揚(yáng)程、大流量的泵站中,其水泵形式為軸流泵。目前關(guān)于軸流泵水力性能和內(nèi)部流動(dòng)特性的文獻(xiàn)較為豐富。施衛(wèi)東[7]對(duì)高比轉(zhuǎn)速低揚(yáng)程軸流泵的水力模型進(jìn)行研究,提出一系列提高效率和抗汽蝕的設(shè)計(jì)方法。王福軍等[8]率先采用瞬態(tài)流理論和大渦模擬方法,對(duì)軸流泵內(nèi)部非定常流動(dòng)進(jìn)行了深入地研究,得到了多工況下軸流泵內(nèi)壓力脈動(dòng)特性。Qian等[9-10]研究了可調(diào)式導(dǎo)葉對(duì)軸流泵的水力性能的影響。鄭源等[11]采用數(shù)值模擬方法和模型試驗(yàn)對(duì)低揚(yáng)程大流量泵裝置馬鞍區(qū)的流動(dòng)特性進(jìn)行研究。張德勝等[12-15]采用大渦模擬方法對(duì)模型軸流泵內(nèi)部非定常流動(dòng)進(jìn)行了數(shù)值模擬研究,獲得了軸流泵葉頂區(qū)湍流特性,并得到試驗(yàn)驗(yàn)證。Li等[16-17]分別采用數(shù)值模擬方法,對(duì)軸流泵內(nèi)部空化流動(dòng)特性進(jìn)行了研究。Liu等[18]研究了停止工況下軸流泵裝置內(nèi)的瞬態(tài)流動(dòng)。Wu等[19]基于RBF神經(jīng)網(wǎng)格方法對(duì)軸流泵系統(tǒng)的動(dòng)力模型進(jìn)行了研究。唐學(xué)林等[20]采用流固耦合方法,對(duì)燈泡貫流泵葉輪強(qiáng)度進(jìn)行研究,并與試驗(yàn)結(jié)果比較。Wang等[21]采用數(shù)值模擬方法對(duì)豎井貫流泵裝置內(nèi)的流固耦合特性進(jìn)行了研究。Kan等[22]采用雙向流固耦合方法,分析了軸伸式貫流泵裝置葉片的壓力動(dòng)力特性。
上述文獻(xiàn)對(duì)軸流泵水力模型的能量性能、空化特性和葉片壓力特性做了大量的研究工作,為貫流泵裝置的水力模型設(shè)計(jì)提供豐富的資料。但是,影響貫流泵裝置水力性能的因素,除了水泵的水力模型之外,還有貫流泵裝置的過流部件。研究表明[23],貫流泵裝置的過流部件對(duì)整個(gè)裝置的水力性能有較大的影響。目前對(duì)于潛水貫流泵裝置過流部件水力性能分析優(yōu)化的研究,未見報(bào)道。
本文采用CFD軟件ANSYS CFX,對(duì)設(shè)計(jì)工況下潛水貫流泵裝置的過流部件水力性能進(jìn)行分析研究,并通過模型試驗(yàn)對(duì)計(jì)算結(jié)果進(jìn)行驗(yàn)證,以期潛水貫流泵裝置在實(shí)際工程中推廣應(yīng)用提供參考。
潛水貫流泵裝置的過流部件包括進(jìn)水流道、葉輪、導(dǎo)葉、燈泡體和出水流道,其中燈泡體由支撐片、進(jìn)線孔和燈泡體尾部組成,如圖1所示。葉輪水力模型型號(hào)為ZM25,葉輪直徑為300 mm,葉頂間隙為0.15 mm,輪轂比為0.36,葉片數(shù)為3,配套導(dǎo)葉葉片數(shù)為5,轉(zhuǎn)速為1 067 r/min。設(shè)計(jì)流量為 270 L/s。

圖1 潛水貫流泵裝置全流道示意圖
采用分塊策略對(duì)潛水貫流泵裝置進(jìn)行六面體網(wǎng)格剖分。進(jìn)、出水流道選用O型拓?fù)浣Y(jié)構(gòu),便于對(duì)邊界層進(jìn)行加密。借鑒相關(guān)文獻(xiàn)的方法[24],葉輪采用H/J/L-Grid拓?fù)浣Y(jié)構(gòu),導(dǎo)葉選用H-Grid拓?fù)浣Y(jié)構(gòu)。為獲得更為精確的結(jié)果,對(duì)葉片周邊區(qū)域的網(wǎng)格進(jìn)行加密處理,整個(gè)計(jì)算域內(nèi)+值在30~500之間[24-27]。進(jìn)水流道和葉輪的網(wǎng)格如圖2所示。

圖2 進(jìn)水流道和葉輪網(wǎng)格
為提高計(jì)算精度,排除網(wǎng)格數(shù)量對(duì)計(jì)算結(jié)果的影響,同時(shí)適當(dāng)減少計(jì)算時(shí)長,對(duì)整個(gè)計(jì)算域進(jìn)行了網(wǎng)格敏感性分析。網(wǎng)格節(jié)點(diǎn)數(shù)達(dá)到1 258 795個(gè)后,泵裝置揚(yáng)程和葉片扭矩波動(dòng)值均小于1%。
相關(guān)文獻(xiàn)研究表明[28-29],RNG湍流模型考慮分離流動(dòng)和渦旋的效應(yīng),適用于泵裝置的數(shù)值計(jì)算。采用Scalable wall function處理近壁區(qū)流動(dòng)。進(jìn)口條件采用質(zhì)量進(jìn)口,出口邊界設(shè)置為壓力出口。
針對(duì)潛水貫流泵裝置的結(jié)構(gòu)特點(diǎn),本文選取3個(gè)關(guān)鍵過流部件的5種參數(shù)進(jìn)行研究,具體為燈泡體中支撐片的數(shù)量和尾部形狀、電纜進(jìn)線孔斷面形狀和位置,以及進(jìn)水流道的過渡形狀。由于研究參數(shù)較多,本文采用單因數(shù)控制方法,依次對(duì)各過流部件的結(jié)構(gòu)參數(shù)進(jìn)行研究,首先研究過流部件結(jié)構(gòu)參數(shù)是支撐片的數(shù)量,后續(xù)研究均以前面研究較優(yōu)結(jié)果為基礎(chǔ)。共研究了9種結(jié)構(gòu)方案,其中方案1、2和3研究燈泡體支撐片數(shù)量,分別對(duì)應(yīng)為3片、5片和7片;方案2、4和5研究燈泡體尾部形狀,分別對(duì)應(yīng)為圓臺(tái)體、半圓球體和半橢球體;方案5、6、7和8研究電纜進(jìn)線孔的型式,分為斷面形狀和位置,其中方案5不設(shè)置進(jìn)線孔,方案6和方案7的斷面形狀分別為圓形和流線形,進(jìn)線孔的位置在支撐片之間,方案8的進(jìn)線孔斷面形狀為流線形,位置在支撐片上;方案8和方案9研究進(jìn)水流道的過渡形狀,方案3為最初方案。
圖3和圖4分別為設(shè)計(jì)工況下,支撐片上的靜壓分布和燈泡體的流線圖。由圖3與圖4可知,方案1、2和3在各支撐片間的靜壓分布均勻,順?biāo)鞣较蜢o壓逐步降低,未見局部靜壓突變區(qū)域,支撐片之間的流線變化平順,沒有回流、漩渦等不良流態(tài),表明支撐片數(shù)量的增加,對(duì)燈泡體內(nèi)的水流流動(dòng)擾動(dòng)較小。

圖3 不同方案支撐片靜壓分布

圖4 不同方案燈泡體流線圖
表1為不同支撐片數(shù)方案的水力損失。由表1可知,方案1、2和3的燈泡體水力損失占整個(gè)泵裝置水力損失的比重約在30%左右,表明燈泡體的水力性能優(yōu)化對(duì)潛水貫流泵裝置能量特性提高有重要影響。隨著支撐片數(shù)量的增加,燈泡體水力損失隨之增大,但支撐片數(shù)量為5時(shí)(方案2),泵裝置的水力損失最小。

表1 不同支撐片數(shù)方案的水力損失
為了解導(dǎo)葉和支撐片之間水流擴(kuò)散狀態(tài),對(duì)導(dǎo)葉和支撐片之間的軸向速度均勻度[30]變化進(jìn)行了分析。圖5a為軸向速度分布均勻度的取樣斷面示意圖,圖5b為方案1、2和3的導(dǎo)葉和支撐片之間軸向速度均勻度的變化。如圖5b所示,方案1、2和3的軸向速度均勻度在導(dǎo)葉出口(斷面1)上相近,在之后的斷面上均逐漸增大,其中方案2的軸向速度均勻度在各個(gè)斷面上均大于方案1和方案3。這表明,方案2(5片支撐片)中水流在導(dǎo)葉和支撐片之間的擴(kuò)散要優(yōu)于方案1和方案3。

圖5 導(dǎo)葉與支撐片間的流動(dòng)特性
圖6為燈泡體尾部縱斷面流態(tài)。由圖6可知,方案2燈泡體尾部有漩渦,由于方案2的尾部形式結(jié)構(gòu)上的特點(diǎn):底部與燈泡不是平順的連接以及頭部的凸臺(tái)狀形式,這兩處水流的穩(wěn)定狀態(tài)被破壞,水流擾動(dòng)劇烈,產(chǎn)生漩渦。方案4作了相應(yīng)的改進(jìn),采用半圓球體的尾部形式,使得水流能夠平順的擴(kuò)散,得到較好的流態(tài)。由于橢球的斷面形式較圓形更具有流線形的特征,能改變流體在尾部脫離點(diǎn)位置,獲得更好的流態(tài), 方案5采用半橢球體。表3為不同尾部形式方案的水力損失。由表2可知,方案5(半橢球體)的燈泡體水力損失為31 mm,較方案2的減少14 mm,較方案4減少了3 mm,且方案5裝置的水力損失較方案2減少了17 mm,較方案4減少了6 mm。這表明燈泡體尾形式的改變,不僅會(huì)影響燈泡體的水力性能,對(duì)泵裝置其他部件的性能也有所改善,也與上述流態(tài)的結(jié)果相吻合。

圖6 燈泡體尾部縱斷面流態(tài)

表2 不同尾部形式方案的水力損失
綜上,潛水貫流泵裝置宜采用半橢球體的燈泡體尾部形式。
圖7和圖8分別為方案5、6、7和8的燈泡體表面和燈泡體支撐片末端斷面靜壓分布。表4為上述方案燈泡段和裝置的水力損失。由圖7和圖8可知,無電纜進(jìn)線孔(方案5),燈泡體表面靜壓沿水流流動(dòng)方向逐漸減小,沒有局部靜壓突變的區(qū)域,各個(gè)支撐片以及支撐片之間的燈泡體表面靜壓變化一致。支撐片末端斷面上,5個(gè)扇形面上靜壓分布也是近乎一致的。在2個(gè)支撐片之間設(shè)置電纜進(jìn)線孔時(shí)(方案6),燈泡體表面的靜壓分布與方案5不同,在進(jìn)線孔兩側(cè)形成局部低壓區(qū),所在位置的支撐片前端靜壓較其他支撐片高。在支撐片末端斷面上,進(jìn)線孔后的扇形面上存在局部高壓區(qū),但其他扇形面的靜壓分布與方案5近乎一致。由表3可知,方案5的水力損失為31 mm,方案6的水力損失為36 mm,相對(duì)與方案5增大了16%。表明進(jìn)線孔會(huì)影響燈泡體的水流流態(tài),增大燈泡體和泵裝置的水力損失。

圖7 燈泡體表面靜壓分布

圖8 支撐片末端斷面靜壓分布

表3 不同進(jìn)線孔型式方案的水力損失
進(jìn)線孔橫斷面形狀由圓形(方案6)變?yōu)榱骶€形(方案7)時(shí),支撐片末端斷面上的局部高壓區(qū)變小,其他區(qū)域的靜壓分布變化較小,方案7燈泡體的水力損失為35 mm,與方案6相比,僅僅減少了1 mm,表明與圓形進(jìn)線孔相比,流線形進(jìn)線孔略微改善進(jìn)線孔后方的水流流態(tài),但對(duì)燈泡體和泵裝置的水力損失影響較小。
進(jìn)線孔的位置由支撐片之間(方案7)改成支撐片之上(方案8),對(duì)燈泡體表面的靜壓分布有明顯的改善。方案7的進(jìn)線孔前后均有局部高壓區(qū),兩側(cè)有局部低壓區(qū),水流流動(dòng)變化急劇。與此相比,方案8進(jìn)線孔周圍的靜壓變化較為平順,支撐片末端斷面上未見局部高壓區(qū),減少了進(jìn)線孔由于阻水分流和尾跡帶來流場擾動(dòng),因而水力損失較?。ㄒ姳?)。
潛水貫流泵裝置的進(jìn)線孔宜采用流線形的斷面,并與支撐片結(jié)合在一起。
圖9方案8和方案9進(jìn)水流道近壁面流線圖。表5為方案8和方案9的進(jìn)水流道水力損失和進(jìn)水流道出口流速分布均勻度。由圖9可知,方案8進(jìn)水流道近壁面流線較為平順,方案9進(jìn)水流道近壁面流線在第二道門槽上流線紊亂。由表4可知,方案8的水力損失較小,流速分布均勻度較高,能提供較好的水泵入流條件。表明在兩道閘門槽之間的過渡形式宜采用漸縮方管,既能避免因閘門槽部位過流斷面急劇變化而造成的不良流態(tài),又能方便工程施工。

圖9 進(jìn)水流道流態(tài)

表4 不同進(jìn)水流道過渡形狀方案的水力損失及進(jìn)水流道出口流速分布均勻度
方案3為最初方案,方案8為優(yōu)化方案。與方案3相比,方案8對(duì)3種過流部件的5種結(jié)構(gòu)參數(shù)進(jìn)行了優(yōu)化,優(yōu)化后的過流部件參數(shù)包括支撐片數(shù)量(5片)、燈泡體尾部形狀(半橢球體)、進(jìn)線孔斷面形狀(流線形)和位置(支撐片上),以及進(jìn)水流道的過渡形式(漸縮方管)。
圖10為方案8和方案3的泵裝置能量性能對(duì)比。由圖可知,當(dāng)流量系數(shù)/BEP為1時(shí)(為泵裝置流量,L/s;BEP為試驗(yàn)的泵裝置最高效率點(diǎn)對(duì)應(yīng)的流量,L/s),方案3的揚(yáng)程系數(shù)/BEP為0.89(為泵裝置揚(yáng)程,m;BEP為試驗(yàn)的泵裝置最高效率點(diǎn)對(duì)應(yīng)的流量,m),效率為75.5%;方案8的揚(yáng)程系數(shù)/BEP為1.01,效率為78.0%。方案8較方案3在最優(yōu)點(diǎn)效率提高了2.5%。

注:Q為泵裝置流量,L·s-1;QBEP為試驗(yàn)最高效率點(diǎn)對(duì)應(yīng)的流量,L·s-1;H為泵裝置揚(yáng)程,m;HBEP為試驗(yàn)最高效率點(diǎn)對(duì)應(yīng)的揚(yáng)程,m。
為驗(yàn)證潛水貫流泵裝置數(shù)值計(jì)算結(jié)果的可靠性,采用物理模型進(jìn)行能量性能測(cè)試。物理模型的葉輪直徑為300 mm,葉頂間隙為0.15 mm,輪轂比為0.36,葉片數(shù)為3,配套導(dǎo)葉葉片數(shù)為5,試驗(yàn)轉(zhuǎn)速為1 067 r/min。物模試驗(yàn)在經(jīng)過中國計(jì)量認(rèn)證的水力試驗(yàn)臺(tái)上進(jìn)行,試驗(yàn)參數(shù)測(cè)量參照SL140-2006《水泵模型及裝置模型驗(yàn)收試驗(yàn)規(guī)程》。潛水貫流泵裝置物理模型如圖11所示。試驗(yàn)結(jié)果與計(jì)算結(jié)果比較如圖12所示。試驗(yàn)和計(jì)算得到的流量-揚(yáng)程曲線在計(jì)算最高效率點(diǎn)(/BEP=1)處交叉,在大流量區(qū)(/BEP>1.05),計(jì)算預(yù)測(cè)的揚(yáng)程大于試驗(yàn)值,在小流量區(qū)(/BEP<1)計(jì)算預(yù)測(cè)的揚(yáng)程小于試驗(yàn)值。在最高效率點(diǎn),揚(yáng)程和流量預(yù)測(cè)的不確定度在1%以內(nèi)。流量系數(shù)/BEP在0.98~1.16范圍內(nèi),計(jì)算預(yù)測(cè)的效率在70%以上,與試驗(yàn)結(jié)果吻合較好。數(shù)值計(jì)算結(jié)果是可信的。

圖11 潛水貫流泵裝置物理模型

圖12 泵裝置外特性曲線對(duì)比
本文比較了不同支撐片數(shù)量對(duì)泵裝置水力性能的影響,結(jié)果表明,隨著支撐片數(shù)量的增加,燈泡體的水力損失隨之增大,但當(dāng)支撐片數(shù)目與導(dǎo)葉一致時(shí),整個(gè)泵裝置的水力損失最小。
比較了圓臺(tái)體、圓球體和橢圓體3種尾部形式對(duì)泵裝置水力性能影響。采用半橢球體的燈泡體尾部形式,能避免回流、脫流等不良流態(tài)的產(chǎn)生,減小泵裝置的水力損失。潛水貫流泵裝置電纜進(jìn)線孔的形狀和位置對(duì)該處水流態(tài)有明顯的影響。采用流線形的進(jìn)線孔,并且將進(jìn)線孔與支撐片結(jié)合在一起,有助于改善出水燈泡體的流態(tài),提高裝置效率。
潛水貫流泵裝置防洪事故門槽和檢修門槽之間的進(jìn)水流道過渡形式,對(duì)進(jìn)水流道內(nèi)的流態(tài)有明顯影響。采用漸縮方管的形式,能獲得較好的進(jìn)水流態(tài),并且也方便工程施工。優(yōu)化后潛水貫流泵裝置在最優(yōu)工況點(diǎn)的效率提高2.5%,達(dá)到78.0%。
采用模型試驗(yàn)對(duì)優(yōu)化后的潛水貫流泵裝置的水力性能進(jìn)行驗(yàn)證,在最高效率點(diǎn),揚(yáng)程和流量預(yù)測(cè)的不確定度小于1%,試驗(yàn)與數(shù)值計(jì)算結(jié)果吻合較好。
[1] 張仁田,單海春,卜舸,等. 南水北調(diào)東線一期工程燈泡貫流泵結(jié)構(gòu)特點(diǎn)[J]. 排灌機(jī)械工程學(xué)報(bào),2016,34(9):774-782,789. Zhang Rentian, Shan Haichun, Bu Ge, et al. Structural features of bulb tubular pumps in first phase of South-to- NorthWater Diversion Eastern Route Project in China[J]. Journal of Drainage and Irrigation Machinery Engineering, 2016, 34(9): 774-782, 789 (in Chinese with English abstract)
[2] 徐磊,陸林廣,陳偉,等. 南水北調(diào)工程邳州站豎井貫流泵裝置進(jìn)出水流態(tài)分析[J]. 農(nóng)業(yè)工程學(xué)報(bào),2012,28(6):50-56. Xu Lei, Lu Linguang, Chen Wei, et al. Flow pattern analysis on inlet and outlet conduit of shaft tubular pump system of Pizhou pumping station in South-to-North Water Diversion Project[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2012, 28(6): 50-56. (in Chinese with English abstract)
[3] 金燕. 貫流泵內(nèi)部流動(dòng)的數(shù)值模擬與三維LDV測(cè)量研究[D]. 揚(yáng)州:揚(yáng)州大學(xué),2010. Jin Yan. Study on the Numerical Simulation and 3D-LDV Measurement of Tubular Pump[D]. Yangzhou: Yangzhou University, 2010. (in Chinese with English abstract)
[4] 馮旭松,關(guān)醒凡,井書光,等. 南水北調(diào)東線燈泡貫流泵水力模型及裝置研究開發(fā)與應(yīng)用[J]. 南水北調(diào)與水利科技,2009,7(6):32-35.Feng Xusong, Guan Xingfan, Jing Shuguang, et al. Development and application on hydraulic model and equipment of bulb tubular pumps in the eastern route of the south-to-north water transfer project[J]. South-to-North Water Transfers and Water Science & Technology, 2009, 7(6): 32-35. (in Chinese with English abstract)
[5] 楊帆,金燕,劉超,等. 雙向潛水貫流泵裝置性能試驗(yàn)與數(shù)值分析[J]. 農(nóng)業(yè)工程學(xué)報(bào),2012,28(16): 60-67. Yang Fan, Jin Yan, Liu Chao, et al. Numerical analysis and performance test on diving tubular pumping system with symmetric aerofoil blade[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2012, 28(16): 60-67. (in Chinese with English abstract)
[6] Dijksman J F. Hydrodynamics of small tubular pumps [J]. Journal of Fluid Mechanics, 1984, 139: 173-191.
[7] 施衛(wèi)東. ZM931高比轉(zhuǎn)數(shù)軸流泵水力模型的設(shè)計(jì)[J]. 農(nóng)業(yè)機(jī)械學(xué)報(bào),1998,29(2):49-53. Shi Weidong. Design of Axial Flow Pump Hydraulic model Zm931 on high specific speed [J]. Transactions of the Chinese Society for Agricultural Machinery, 1998, 29(2): 49-53. (in Chinese with English abstract)
[8] 王福軍,張玲,張志民. 軸流泵不穩(wěn)定流場的壓力脈動(dòng)特性研究[J]. 水利學(xué)報(bào),2007,38(8):1003-1009. Wang Fujun, Zhang Ling, Zhang Zhimin. Analysis on pressure fluctuation of unsteady flow in axial-flow pump [J]. Journal of Hydraulic Engineering, 2007, 38(8): 1003-1009. (in Chinese with English abstract)
[9] Qian Z, Wang F, Guo Z, et al. Performance evaluation of an axial-flow pump with adjustable guide vanes in turbine mode[J]. Renewable Energy, 2016, 99: 1146-1152.
[10] 錢忠東,王凡,王志遠(yuǎn),等. 可調(diào)導(dǎo)葉式軸流泵馬鞍區(qū)水力特性試驗(yàn)研究[J]. 排灌機(jī)械工程學(xué)報(bào),2013,31(6):461-465. Qian Zhongdong, Wang Fan, Wang Zhiyuan, et al. Experimental study on hydraulic performance of saddle zone in axial flow pump with adjustable guide vane[J]. Journal of Drainage and Irrigation Machinery Engineering, 2013, 31(6): 461-465. (in Chinese with English abstract)
[11] 鄭源,茅媛婷,周大慶,等. 低揚(yáng)程大流量泵裝置馬鞍區(qū)的流動(dòng)特性[J]. 排灌機(jī)械工程學(xué)報(bào),2011,29(5):369-373. Zheng Yuan, Mao Yuanting, Zhou Daqing, et al. Flow characteristics of low-lift and large flow rate pump installationin saddle zone[J]. Journal of Drainage and Irrigation Machinery Engineering, 2011, 29(5): 369-373. (in Chinese with English abstract)
[12] 張德勝,石磊,陳健,等. 基于大渦模擬的軸流泵葉頂泄漏渦瞬態(tài)特性分析[J]. 農(nóng)業(yè)工程學(xué)報(bào),2015,31(11):74-80. Zhang Desheng, Shi Lei, Chen Jian, et al. Analysis on transient characteristics of tip leakage vortex in axial flow pump using large eddy simulation[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2015, 31(11): 74-80. (in Chinese with English abstract)
[13] Zhang D, Shi L, Zhao R, et al. Study on unsteady tip leakage vortex cavitation in an axial-flow pump using an improved filter-based model[J]. Journal of Mechanical Science & Technology, 2017, 31(2): 659-667.
[14] Zhang D, Shi W, Pan D, et al. Numerical and experimental investigation of tip leakage vortex cavitation patterns and mechanisms in an axial flow pump[J]. Journal of Fluids Engineering, 2015, 137(12): 815-816.
[15] Zhang D, Shi W, Esch B P M V, et al. Numerical and experimental investigation of tip leakage vortex trajectory and dynamics in an axial flow pump[J]. Computers & Fluids, 2013, 112(1): 61-71.
[16] Li Z, Zhang N, Hong B, et al. Simulation research on cavitation flow in tip clearance of axial-flow pump[J]. Journal of Engineering Thermophysics, 2011, 588(8): 1255-1258.
[17] Feng W, Cheng Q, Guo Z, et al. Simulation of cavitation performance of an axial flow pump with inlet guide vanes[J]. Advances in Mechanical Engineering, 2016, 8(6): 1-8.
[18] Liu Y, Zhou J, Zhou D. Transient flow analysis in axial-flow pump system during stoppage[J]. Advances in Mechanical Engineering, 2017, 9(9): 1-8.
[19] Wu Q, Wang X, Shen Q. Research on dynamic modeling and simulation of axial-flow pumping system based on RBF neural network[J]. Neurocomputing, 2016, 186: 200-206.
[20] 唐學(xué)林,王秀葉,賈玉霞. 基于流固耦合的燈泡貫流泵葉輪強(qiáng)度分析[J]. 排灌機(jī)械工程學(xué)報(bào),2014,32(11):921-926. Tang Xuelin, Wang Xiuye, Jia Yuxia. Strength analysis of bulb tubular pump impeller based on fluid-structure interaction[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2014, 32(11): 921-926. (in Chinese with English abstract)
[21] Wang S, Zhang L, Yin G. Numerical investigation of the fsi characteristics in a tubular pump[J]. Mathematical Problems in Engineering, 2017(17): 1-9.
[22] Kan K, Zheng Y, Fu S, et al. Dynamic stress of impeller blade of shaft extension tubular pump device based on bidirectional fluid-structure interaction[J]. Journal of Mechanical Science & Technology, 2017, 31(4): 1561-1568.
[23] 仇寶云,裴蓓,申劍,等. 燈泡貫流泵機(jī)組支撐形式比較[J]. 排灌機(jī)械工程學(xué)報(bào),2011,29(1):61-66. Qiu Baoyun, Pei Bei, Shen Jian, et al. Camparison of bulb tubular pump unit’s support forms[J]. Journal of Drainage and Irrigation Machinery Engineering, 2011, 29(1): 61-66. (in Chinese with English abstract)
[24] 楊帆. 低揚(yáng)程泵裝置水動(dòng)力特性及多目標(biāo)優(yōu)化關(guān)鍵技術(shù)研究[D]. 揚(yáng)州:揚(yáng)州大學(xué),2013. Yang Fan. Research on Hydraulic Performance and Multi- objective optimization Design of Low-Lift Pump system [D]. Yangzhou : Yangzhou University, 2013.
[25] 資丹,王福軍,陶然,等. 邊界層網(wǎng)格尺度對(duì)泵站流場計(jì)算結(jié)果影響研究[J]. 水利學(xué)報(bào),2016,47(2):139-149. Zi Dan, Wang Fujun, Tao Ran, et al. Research for impacts of boundary layer grid scale on flow field simulation results in pumping station[J]. Journal of Hydraulic Engineering, 2016, 47(2): 139-149. (in Chinese with English abstract)
[26] Salim S M, Ariff M, Cheah S C. Wall+ approach for dealing with turbulent flows over a wall mounted cube[J]. Progress in Computational Fluid Dynamics An International Journal, 2010, 10(8): 341-351.
[27] Tu J, Yeoh G H, Liu C. Computational fluid dynamics: A practical approach[J]. Artificial Organs, 2013, 33(9): 727-32.
[28] Yang G. Pump Turbine Working Condition of Numerical Simulation and Optimization of the RNGModel[M]. Intelligent Computing Methodologies. Springer International Publishing, 2016: 684-693.
[29] Mostafa N H, Boraey M A. Numerical and experimental investigation of cavitation in axial pumps[J]. International Journal of Manufacturing, 2013, 4(1): 1225-1225.
[30] 劉超. 水泵及水泵站[M].北京:中國水利水電出版社,2009.
Hydraulic performance analysis and optimization on flow passage components of diving tubular pumping system
Xia Chenzhi1, Cheng Li1, Jiang Hongying2, Xin Jian3
(1.225127; 2.210029; 3.225400,)
Diving tubular pump is a kind of low-head large-flow horizontal pump. This type is postpositive bulb pump and the motor is coaxial with pump, which is suitable for irrigation or storm drainage pumping station. For the advantages of excellent hydraulic performance, compact structure, good noise resistance and low operating cost, diving tubular pump is widely applied in low head pumping station. The internal structure of diving tubular pumping system is more complex than other pumping systems for the combination of motor and rotor. Bulb, support slices, cable hole, inlet passage and outlet passage constitute the flow passage components of diving tubular pumping system, which have influence on the internal flow pattern and hydraulic loss of diving tubular pumping system. For low head condition, small increase of hydraulic loss will result in large efficiency loss of pumping system. So the analysis on hydraulic performance of flow passage components of diving tubular pumping system needs to be carried out. In this paper, to acquire hydraulic performance of flow passage components, the inner flow field of diving tubular pumping system is calculated by CFD (computational fluid dynamics). The influence on hydraulic performance of pumping system with different flow passage components is analyzed and the experiment is performed to verify the result of numerical calculation. The head and efficiency difference between model test and CFD simulation are less than 1% in the best efficiency point condition, and the high efficiency range predicted by CFD coincides with the results of the experiment. In order to acquire the influence on hydraulic performance for different numbers of support slices, 3 kinds of slices’ numbers are simulated to show that the number of support slices affects the flow pattern between guide vane and support slice. The hydraulic loss of bulb part increases with the number of support slices. The hydraulic loss of pumping system is relatively lower while the support slices’ number is equal to guide vane’s, which is 5 in this pumping system. Also the shape of bulb tail of pumping system has influence on the flow pattern in outlet passage. Three kinds of bulb tail shapes are calculated, including cone, semi-ellipsoid and semi-sphere. Cone is bad shape for bulb tail, due to the bad flow pattern caused by blunt tail. Semi-sphere is better than cone for less hydraulic loss and better flow expansion in outlet passage. Compared to cone and semi-sphere, semi-ellipsoid is the best shape for bulb tail, which can prevent bad flow pattern like backflow and flow separation. Cable hole is a small pipe which locates at bulb, and its influence on flow pattern and hydraulic loss is ignored by manufactures for its small volume. This paper compares 2 different section shapes of cable hole, specific circle and streamline shape. The result shows that cable hole causes 16% hydraulic loss of bulb, and streamline shape acquires better pressure distribution on cable hole and slightly enhances the flow pattern behind cable hole. Besides, the combination of cable hole and support slice can improve the flow pattern in bulb part and improve efficiency of pumping system. The transition shape of inlet passage between 2 gate slots is also a key factor on hydraulic performance of diving tubular pumping system. Two transition shapes are calculated, including converging square pipe and converging square-circle pipe. Compared with converging square-circle pipe, converging square pipe decreases hydraulic loss of pumping system by 5% and acquires better flow pattern around gate slots. In addition, the other advantage of converging square pipe is the convenience for construction. In conclusion, the efficiency of optimized diving tubular pumping system increases by 2.5%, which reaches 78%. In best efficiency point, the uncertainty of hydraulic performance between simulation and test result less than 1%.
pumps; computer simulation; optimization; diving tubular pump; flow passage components; model test
夏臣智,成 立,蔣紅櫻,辛 健.潛水貫流泵裝置過流部件水力性能分析與優(yōu)化[J]. 農(nóng)業(yè)工程學(xué)報(bào),2018,34(7):45-51. doi:10.11975/j.issn.1002-6819.2018.07.006 http://www.tcsae.org
Xia Chenzhi, Cheng Li, Jiang Hongying, Xin Jian. Hydraulic performance analysis and optimization on flow passage components of diving tubular pumping system[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2018, 34(7): 45-51. (in Chinese with English abstract) doi:10.11975/j.issn.1002-6819.2018.07.006 http://www.tcsae.org
2017-10-22
2018-01-03
國家自然科學(xué)基金面上(51779214);江蘇省高校優(yōu)勢(shì)學(xué)科建設(shè)工程資助項(xiàng)目(PAPD);江蘇省研究生培養(yǎng)創(chuàng)新工程(KYLX16_1395);江蘇水利科技項(xiàng)目(2016035)
夏臣智,博士生,主要從事泵站工程研究。Email:xiachenzhi@foxmail.com
成 立,教授,博士生導(dǎo)師,主要從事泵站工程研究。Email:chengli@yzu.edu.cn
10.11975/j.issn.1002-6819.2018.07.006
TH31;TV131
A
1002-6819(2018)-07-0045-07