本文選題：核主泵　切入點：口環(huán)間隙　出處：《大連理工大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：葉輪口環(huán)間隙結(jié)構(gòu)的存在與改變會對核主泵的水力性能產(chǎn)生較大影響,本文通過CFX軟件對課題組自主設(shè)計的CAP1400核主泵水力部件進行整機數(shù)值模擬,獲得核主泵的水力性能及其內(nèi)部流場結(jié)構(gòu),并結(jié)合實驗對比驗證數(shù)值模擬的準(zhǔn)確性。分析葉輪口環(huán)間隙尺寸變化對葉輪所受軸向力、整機內(nèi)部壓力脈動特性及葉片水力載荷分布的影響,進而研究核主泵內(nèi)部的水動力特性。核主泵長周期運行過程中,由于高溫環(huán)境產(chǎn)生的熱變形、高速旋轉(zhuǎn)產(chǎn)生的離心力和軸承磨損等綜合因素的影響,使核主泵葉輪口環(huán)間隙的尺寸發(fā)生改變,從而導(dǎo)致其水力性能和水動力特性的變化。考慮在290℃C高溫環(huán)境下葉輪口環(huán)間隙熱變形及長周期軸承磨損的共同影響,分析口環(huán)間隙尺寸變化對核主泵水力性能和水動力特性的影響是目前的研究重點。本文首先分析無口環(huán)間隙的核主泵整機內(nèi)部流動結(jié)構(gòu)和水動力特性,其次通過不同口環(huán)間隙尺寸下整機水力部件的全流道數(shù)值計算,比對分析口環(huán)間隙變化對核主泵的水力性能及流場分布、葉輪所受軸向力和水動力特性的影響。研究發(fā)現(xiàn), (1)考慮葉輪口環(huán)間隙會導(dǎo)致核主泵整機設(shè)計點效率降低1%,揚程降低1.7%,并且隨口環(huán)間隙尺寸增大,整機效率及揚程逐漸減小,葉輪進口處渦量增大,二次流沖擊造成的水力損失增加； (2)口環(huán)間隙的增大會使葉輪前腔的泄漏量逐漸增加,進而導(dǎo)致葉輪前蓋板處軸向力減小5%左右,使得葉輪軸向力增大2.4%-4.5%,方向指向葉輪進口； (3)設(shè)計條件下口環(huán)間隙的存在及尺寸變化對導(dǎo)葉葉片水力載荷的整體分布影響不大,對葉輪葉片中部水力載荷影響最大在8%左右波動,同時,口環(huán)間隙的改變導(dǎo)致葉輪葉片前緣的靜壓載荷突增,產(chǎn)生壓力突變,說明口環(huán)間隙的變化對核主泵的可靠性會產(chǎn)生一定影響。本文的研究主要為長周期運行下核主泵葉輪口環(huán)間隙尺寸變化對其性能、葉輪軸向力、壓力脈動及葉片水力載荷分布的影響分析,為進一步研究口環(huán)間隙對核主泵內(nèi)部水動力特性影響的機理打下基礎(chǔ)。
[Abstract]:The existence and change of the clearance structure of the impeller opening ring will have a great influence on the hydraulic performance of the nuclear main pump. In this paper, the hydraulic components of the CAP1400 nuclear main pump designed by our group are numerically simulated by CFX software. The hydraulic performance of the nuclear main pump and its internal flow field structure are obtained, and the accuracy of the numerical simulation is verified by comparing the experimental results. The axial force on the impeller caused by the change of the clearance size of the impeller orifice ring is analyzed. The characteristics of pressure pulsation and the distribution of hydraulic load on the blade of the whole machine are studied, and the hydrodynamic characteristics of the nuclear main pump are studied. The thermal deformation caused by the high temperature environment during the long period operation of the nuclear main pump is studied. The influence of centrifugal force and bearing wear caused by high speed rotation makes the clearance of impeller ring of nuclear main pump change. This results in the change of hydraulic and hydrodynamic properties of the impeller ring clearance and the wear of long period bearing under the condition of 290 鈩，

本文編號：1569253