本文選題：平行雙閘板閘閥 + 凹槽結構��； 參考：《浙江大學》2013年博士論文

【摘要】：本課題以稀相氣力輸送中的平行雙閘板閘閥為研究對象,對其內部氣固兩相流動特性以及磨損狀況進行了數(shù)值模擬和實驗研究。研究成果為平行雙閘板閘閥的磨損預測以及優(yōu)化設計提供了理論支持。 論文首先對氣相和顆粒相進行了受力分析,建立了平行雙閘板閘閥內部兩相流動和顆粒碰撞磨損的數(shù)學模型,設計了模型的求解方案,并通過文獻中實驗結果進行了驗證。然后基于該數(shù)值模擬方法對平行雙閘板閘閥的內部兩相流動、顆粒碰撞磨損以及磨損改進設計開展了系統(tǒng)的研究。研究中,根據(jù)結構分析,將平行雙閘板閘閥結構簡化為一種管道凹槽結構；通過對凹槽結構的磨損分析,提出了平行雙閘板閘閥關鍵密封面的磨損預測公式,提出了平行雙閘板閘閥的磨損改進設計。最后搭建了管道閥門測試平臺,對凹槽結構開展實驗研究,驗證了改進設計方案的有效性。 課題的主要研究工作如下： 1.閘閥內部稀相氣固兩相流動及磨損的計算模型。針對兩相流動和顆粒碰撞磨損的計算需求,采用歐拉-拉格朗日方法對氣相和固體顆粒相進行處理。為了減小計算時間以及計算難度,提出了關于流體可壓縮性、顆粒粒徑、顆粒碰撞等計算假設。根據(jù)提出計算假設,通過對湍流計算方法的對比分析,建立了連續(xù)相湍流計算模型；通過分析顆粒的受力狀況、流場的湍流脈動對顆粒的作用以及顆粒與壁面之間的相互作用規(guī)律等顆粒運動參數(shù),建立了基于隨機游走方法的顆粒動力學計算模型；通過對單顆粒磨損模型進行選取,并結合泰勒級數(shù)展開技術,建立了顆粒碰撞磨損計算模型。 2.平行雙閘板閘閥內部稀相氣固兩相流動研究。對平行雙閘板閘閥內部稀相兩相流動及相間作用進行了三維數(shù)值模擬研究,分析了不同閥門放置方式以及不同閥門開度下,顆粒對氣體相流場的影響,并著重考察了閥門的放置方式(水平放置和豎直放置)對閥門內部顆粒運動軌跡的影響,獲得了顆粒對流場的作用規(guī)律以及流場作用下不同粒徑顆粒運行軌跡的變化規(guī)律。 3.平行雙閘板閘閥內部顆粒碰撞磨損研究。平行雙閘板閘閥主要工作在全開工況下,因此基于結構分析將閥門簡化為一個管道凹槽結構,并對簡化結構開展顆粒碰撞磨損的三維數(shù)值模擬研究。由于雙閘板閘閥內部關鍵密封面處的顆粒碰撞磨損最為嚴重,在研究中重點關注凹槽后壁面的磨損狀況,并且引入了總磨損率對磨損程度進行定量分析。研究首先分析了簡化結構放置方式對后壁面磨損分布的影響,指出水平放置狀況下后壁面磨損主要集中在下半部分(T面),其磨損程度遠遠大于豎直放置狀況(特別是對于大顆粒)；于是著重考察了水平放置情況下流動和結構參數(shù)(固氣比、顆粒直徑、進口速度、凹槽寬度、凹槽深度和管道直徑)的變化對T面總磨損率的影響規(guī)律；接著基于數(shù)值模擬結果和曲面擬合技術,提出了水平放置的平行雙閘板閘閥關鍵密封面下半部分的總磨損率預測公式,并通過16組正交算例的公式預測結果與數(shù)值計算結果的對比分析,驗證了磨損預測公式的準確性；最后結合前人提出的單顆粒碰撞的磨損模型對磨損預測公式進行了擴展,增加了其適用范圍。 4.基于凹槽結構的閥門磨損改進研究。論文對水平放置的前后壁面存在高度差(前壁面高于后壁面)的凹槽結構開展了兩相流動及顆粒碰撞磨損二維數(shù)值模擬研究,首先分析高度差對氣相流場的影響,然后對比分析了高度差對不同粒徑的顆粒分布的作用規(guī)律,最后考察了高度差的變化對凹槽下游下表面的磨損速率分布規(guī)律以及凹槽結構后壁面最大磨損速率的影響規(guī)律。研究結果指出微小的高度差結構能夠明顯地減小凹槽后壁面的最大磨損速率。根據(jù)該結果,提出了凹槽結構上下游管道不等內徑(上游管道內徑略小于下游管道內徑)的平行雙閘板閘閥磨損改進設計方案。 5.凹槽結構磨損的實驗研究。采用高速攝像、表面形貌測量等實驗方法對凹槽結構的磨損進行研究,分析了凹槽內顆粒的分布隨高度差的變化規(guī)律,并討論了凹槽后壁面磨損的分布規(guī)律以及高度差對凹槽后壁面最大磨損量的影響,實驗研究再次表明微小的高度差結構能夠極大地改善凹槽后壁面的磨損,論文同時將實驗結果與凹槽結構的數(shù)值模擬結果進行對比,進一步驗證了數(shù)值模擬方法的準確性。
[Abstract]:In this paper , the parallel double gate valve gate valve in dilute phase pneumatic conveying is used as the research object , and the numerical simulation and experimental research on the gas - solid two - phase flow characteristics and wear conditions are carried out . The research results provide theoretical support for the wear prediction and optimization design of the parallel double gate valve .

Based on the structural analysis , the parallel double gate gate valve structure is simplified into a pipe groove structure .
Through the analysis of the wear of the groove structure , the wear prediction formula of the key sealing surface of the parallel double gate valve gate valve is put forward , and the wear improving design of the parallel double gate valve is put forward . Finally , the test platform of the pipeline valve is set up , and the experiment research is carried out on the groove structure , and the effectiveness of the improved design scheme is verified .

The main research work of the subject is as follows :

1 . The calculation model of two - phase flow and wear of dilute phase gas in gate valve is presented . In order to reduce the calculation time and the difficulty of calculation , the calculation assumption about compressibility of fluid , particle size , particle collision and so on is put forward .
By analyzing the force state of the particles , the effect of the turbulence pulsation on the particles and the interaction between the particles and the wall surface , a particle dynamics calculation model based on the random walk method is established .
By selecting the single particle wear model and combining the Taylor series expansion technique , a model of particle impact wear calculation is established .

2 . A three - dimensional numerical simulation study on the two - phase flow and the phase effect of the internal dilute phase of a parallel double gate gate valve is carried out . The influence of different valve placement modes and different valve opening degrees on the gas phase flow field is analyzed , and the influence of the placement mode of the valve ( horizontal placement and vertical placement ) on the movement locus of the inner particles of the valve is studied , and the law of action of the particle convection field and the variation law of the running track of different particle size particles under the action of the flow field are obtained .

3 . Parallel double gate valve gate valve internal particle impact wear research . The parallel double gate gate valve is mainly operated under full open condition , so the valve is simplified into a pipe groove structure based on structural analysis , and the three - dimensional numerical simulation study of particle impact wear on the simplified structure is carried out .
Then the influence of the change of flow and structure parameters ( solid - gas ratio , particle diameter , inlet velocity , groove width , groove depth and pipe diameter ) on the total wear rate of T - face was investigated .
Then , based on the numerical simulation results and the surface fitting technology , a formula for predicting the total wear rate of the lower half of the key sealing surface of the parallel double gate valve gate valve is put forward , and the accuracy of the wear prediction formula is verified by the comparison between the formula prediction result of 16 groups and the numerical results .
Finally , the wear model of single particle collision proposed by the former is extended to the wear prediction formula , and the application scope is increased .

In this paper , two - phase flow and particle impact wear two - dimensional numerical simulation research is carried out on the groove structure of the front and rear wall surfaces of the horizontal placement . The influence of the height difference on the gas phase flow field is analyzed . Finally , the effect of height difference on the wear rate distribution law of the lower surface of the groove and the maximum wear rate of the wall surface of the groove structure are analyzed .

5 . Experimental study on the wear of the groove structure . The wear of the groove structure is studied by means of high speed camera , surface topography measurement and so on . The distribution law of the surface wear after the groove and the influence of the height difference on the maximum wear amount of the rear wall surface of the groove are discussed . The experimental study shows that the small height difference structure can greatly improve the wear of the rear wall of the groove , and the experimental results are compared with the numerical simulation results of the groove structure , and the accuracy of the numerical simulation method is further verified .
【學位授予單位】：浙江大學
【學位級別】：博士
【學位授予年份】：2013
【分類號】：TH134

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