本文關(guān)鍵詞：螺旋槽干氣密封高壓端面變形機理的理論與實驗研究　出處：《浙江工業(yè)大學(xué)》2014年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 干氣密封 機械變形 扭轉(zhuǎn)變形 膜壓變形 磨損 密封性能

【摘要】：隨著流體機械向高速、高壓等工況的發(fā)展,密封環(huán)端面高壓機械變形導(dǎo)致的磨損失效問題日益突出。論文對高壓工況下干氣密封的氣膜特性、端面變形機理和變化規(guī)律開展了理論與實驗研究,主要工作包括： 首先,在對氣膜實際特性影響分析中,基于氣體潤滑理論,綜合考慮密封氣膜的熱力學(xué)特性和表面微尺度效應(yīng),建立了高壓氣膜潤滑密封特性分析模型,揭示了高壓工況下熱粘效應(yīng)、表面粗糙度效應(yīng)、界面滑移效應(yīng)對密封端面氣膜壓力分布及密封性能的影響規(guī)律。研究發(fā)現(xiàn),高壓實際熱力過程與等溫過程相近；熱粘效應(yīng)能提高密封承載力,并對密封性能影響起主導(dǎo)作用；表面粗糙度有利于提高密封動壓效應(yīng)及穩(wěn)定性,降低泄漏量；滑移流效應(yīng)使泄漏率增大。 接著,分別基于圓環(huán)理論和彈性力學(xué)基本理論,建立扭轉(zhuǎn)變形無量綱計算模型和流固耦合計算模型,提出端面膜壓引起端面扭轉(zhuǎn)變形的計算方法,結(jié)果表明： 膜壓變形可提高密封穩(wěn)定性和動壓效應(yīng),但泄漏率增大；當(dāng)po≥3MPa時,開啟力受其影響較小,而泄漏率和穩(wěn)定性影響相對較大；當(dāng)h0≥3μm時,膜壓變形的影響可忽略不計。本文操作條件下螺旋槽端面幾何參數(shù)優(yōu)選值為槽數(shù)Ng=12,槽深比H2=3,螺旋角α15°,槽壩比ψ=0.7,槽臺寬比e=1.0。 扭轉(zhuǎn)變形使端面沿泄漏方向形成發(fā)散間隙,復(fù)雜截面密封環(huán)上臺階的長或?qū)捫∮?mm時,可直接忽略臺階影響。扭轉(zhuǎn)角隨臺階半徑比和長度比以及O形圈位置的長度比的增大而增大,隨臺階寬度比、內(nèi)徑的增大而減少,其中臺階寬度比的影響最為顯著；相比密封結(jié)構(gòu),O形圈位置影響較小。 綜合變形使端面形成發(fā)散間隙,其中以扭轉(zhuǎn)變形的影響為主,結(jié)構(gòu)因素在高壓干氣密封設(shè)計中占主導(dǎo)地位。綜合變形使開啟力降低,泄漏率增大；高壓條件下,轉(zhuǎn)速對密封膜壓、膜厚和變形的影響不大。單位面積所受承載力大的靜環(huán)(結(jié)構(gòu)b)端面變形和膜厚大于承載力小(結(jié)構(gòu)a)的環(huán),結(jié)構(gòu)a的開啟力大于結(jié)構(gòu)b,結(jié)構(gòu)a的泄漏量小于結(jié)構(gòu)b。當(dāng)0型圈的位置遠離密封端面(a處)時,端面變形影響較大,密封端面開啟較為困難,泄漏量大；當(dāng)O型圈的位置接近密封端面(1)處)時,端面變形影響較小,開啟相對容易,泄漏量小,但影響不如結(jié)構(gòu)尺寸的影響顯著。 最后,通過搭建高壓干氣密封實驗臺,測試膜厚、泄漏率、端面磨損等數(shù)據(jù),研究了高壓干氣密封端面的變形機理。實驗表明：實測泄漏率及膜厚與理論計算值趨勢一致,數(shù)值結(jié)果基本吻合。5MPa壓力下各結(jié)構(gòu)因素的膜厚在4.0μm至6.1μm之間,此時密封具有良好的靜壓開啟性能。結(jié)構(gòu)因素對密封開啟性能影響較大,結(jié)構(gòu)尺寸對變形和密封性能的影響大于密封圈位置的影響,運行后的密封端面外徑處出現(xiàn)磨損,沿徑向的磨損長度、磨損量、粗糙度及泄漏率的分布或變化規(guī)律與理論計算結(jié)果一致,驗證了高壓干氣密封變形和磨損之間的關(guān)系和上述分析計算模型的合理性。 論文的研究成果系統(tǒng)地完善了干氣密封高壓變形的理論,可為高壓干氣密封端面抗變形設(shè)計及其工程應(yīng)用提供理論依據(jù)。
[Abstract]:With the high-speed development of fluid machinery, high pressure conditions, high pressure mechanical deformation of seal rings wear caused problems have become increasingly prominent. The characteristic of gas film under high pressure dry gas seal, deformation mechanism and variation law carried out theoretical and experimental research, the main work includes:
First of all, in the analysis of the actual effect on properties of the film, based on gas lubrication theory, considering the thermodynamic properties and the surface of the gas film seal effect of micro scale, a high pressure gas film lubrication analysis model of sealing characteristics, reveals the thermal viscosity effect under high pressure, the effect of surface roughness, interface slip effect on the influence of gas seal film face pressure distribution and sealing performance. The study found that the high pressure thermal process and isothermal process similar; thermo viscosity effect can improve the sealing capacity, and the leading role of the sealing performance effect; surface roughness can improve the sealing effect of dynamic pressure and stability, reducing leakage; slip flow effects of the leakage rate increased.
Then, based on the theory of ring and the basic theory of elasticity, the torsional deformation dimensionless calculation model and fluid solid coupling calculation model are established, and the calculation method of torsional deformation caused by end face pressure is put forward.
The membrane deformation can improve the sealing stability and dynamic pressure effect, but the leakage rate increases; when the Po is greater than or equal to 3MPa, the opening force is less affected, while the effect of leakage rate and stability is relatively large; when H0 is larger than 3 m, the effect of membrane deformation can be ignored. The preferred geometric parameters of spiral groove face the operation under the condition of Ng=12 value for the slot number, groove depth ratio H2=3, spiral angle of 15 degrees, slot dam than w =0.7, groove width ratio e=1.0.
The torsional deformation of surface forming along the direction of leakage clearance divergence, complex cross section sealing ring on the steps of the length or width is less than 3mm, can be directly affected. Ignore the torsion angle with the step step radius ratio and length ratio and O ring position length ratio increases with step width ratio, reduced diameter increases the effect of the step width than the most significant; compared with the O shaped sealing structure, smaller ring position.
Comprehensive deformation makes the surface forming divergent gap, the torsional deformation effects, structural factors in high pressure dry gas seal design is dominant. Comprehensive deformation makes the opening force is reduced, the leakage rate increased; under the condition of high pressure, speed of sealing film pressure, film thickness and deformation has little effect. The static unit area the bearing ring (structure b) face deformation and film thickness is greater than the carrying capacity of small (structure a) ring structure a opening force structure is greater than B, the structure of a leakage is less than B. when the structure type 0 circle position away from the sealing surface (a), large end effect, seal face opening is difficult, the large amount of leakage; when the O ring is located close to the seal (1) at the time), effect of end face deformation is small, relatively easy to open, a small amount of leakage, but the influence as structure size significantly.
Finally, through the dry gas seal experimental platform to build test pressure, film thickness, leakage rate, surface wear and other data, the deformation mechanism of high pressure dry gas seal. The experimental results show that the measured leakage rate and film thickness are consistent with theoretical calculation, numerical results coincide each factor structure of.5MPa under pressure in the film thickness between 4 m to 6.1 m, the seal has good static performance. Open structure factors on seal opening performance influence, effects of structure size on the sealing performance of the sealing ring is greater than the effect of deformation and the position of the seal at the outer radius of the end after running wear, wear along the length of the radial wear quantity calculation roughness and leakage rate distribution or variation is consistent with the theoretical result, verified the high pressure dry gas seal deformation and the relationship between the wear and the analysis on the rationality of the model.
The research results of the paper improve the theory of high pressure deformation of dry gas seal, and provide theoretical basis for the design and engineering application of high pressure dry gas seal face.

【學(xué)位授予單位】：浙江工業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TH136

【參考文獻】

相關(guān)期刊論文 前10條

1 劉斌,蔡紀(jì)寧,張秋翔,林培峰;螺旋槽端面干氣密封的參數(shù)研究[J];北京化工大學(xué)學(xué)報(自然科學(xué)版);2002年05期

2 陳學(xué)科，裘祖干;冪律流體的平均流動模型在粗糙徑向滑動軸承中的應(yīng)用[J];復(fù)旦學(xué)報(自然科學(xué)版);1995年06期

3 王樂勤;孟祥鎧;戴維平;吳大轉(zhuǎn);;接觸式機械密封流固耦合模型及性能分析[J];工程熱物理學(xué)報;2008年11期

4 關(guān)雅賢;李松虎;;流體動壓效應(yīng)在機械密封里應(yīng)用——介紹弧形槽流體動力型機械密封[J];北京化工大學(xué)學(xué)報(自然科學(xué)版);1986年04期

5 紀(jì)敬虎;符永宏;魏龍;華�？�;畢勤勝;;激光表面織構(gòu)機械密封潤滑特性的試驗研究[J];排灌機械工程學(xué)報;2011年05期

6 李鯤,姚黎明,吳兆山,王春揚;機械密封環(huán)端面變形研究[J];潤滑與密封;2001年05期

7 趙越,宋鵬云,李偉,曹登峰;螺旋槽氣體潤滑機械密封低速運轉(zhuǎn)特性——理論研究[J];潤滑與密封;2005年05期

8 陳志煥;符永宏;袁潤;王霄;蔡蘭;;全液體潤滑機械密封及其加工技術(shù)[J];潤滑與密封;2005年06期

9 楊寶亮;郝木明;;雙向零泄漏非接觸式機械密封的研究及應(yīng)用[J];潤滑與密封;2006年03期

10 周劍鋒;顧伯勤;;機械密封環(huán)端面變形對液膜特性的影響[J];潤滑與密封;2006年12期

，

本文編號：1440241