摘要
针对DN25单座调节阀在开度较小的工况下有效流通面积很小、前后压差较大和介质流速快而导致空化现象较为严重的情况,利用计算机液体力学(CFD)软件FLUENT对该型调节阀的原始结构进行流场数值模拟,采用Mixture多相流模型、Realizable k-ε湍流模型和Schnerr-Sauer空化模型计算调节阀在10%阀芯开度下内部流场及空化状况。结果表明,该型调节阀的阀座及阀芯密封副表面空化状况较为严重。文中通过改变阀芯的关键参数对其进行了结构优化,并采用相同物理模型经过多次试算,并对计算结果进行比较。结果表明,当阀芯密封面与垂直方向的角度α=50°,阀芯密封面长度L=5. 5 mm,并对阀芯密封面上下两侧拐角倒圆角后,阀芯表面的空化区域可减少60%以上。
When DN25 single-seat regulating valve is opened small,the effective flow area is very small,the pressure difference between front and back is large,and the medium velocity is fast,it produces serious cavitation phenomenon. The flow field of the original structure of the valve was simulated by using CFD software, FLUENT. Mixture multi-phase flow model, Realizable k-εturbulence model and Schnerr-Sauer cavitation model were used to calculate the internal flow field and cavitation status of the valve under 10 % core opening. The results show that cavitation of the surface of the valve seat and the sealing surface of the valve core are serious. The key parameters ofthe spool are changed to optimize the structure. It is found that the cavitation area of the valve core surface decreases by more than 60 % when the angle of the valve core sealing surface and the vertical direction α is 500 and the length of the valve core sealing surface L is 5. 5 mm and the corner of the valve core sealing surface is smoothed.
引文
[1]侯璐瑶.高压差调节阀内部流体流动规律与气蚀仿真研究[D].北京:北京化工大学,2011.
[2]潘森森.空化机理[M].北京:国防工业出版社,2016:1-10.
[3]干瑞彬.高压差高固调节阀内部流场分析及优化[D].兰州:兰州理工大学,2016.
[4] SAITO S,SHIBATA M,FUKAE H,et al. Computational cavitation flows at inception and light stages on an axial-flow pump blade and in a cage-guided control valve[J]. Journal of Thermal Science,2007,16(4):337-345.
[5] AN Y J,KIM B J,SHIN B R. Numerical analysis of 3-D flow through LNG marine control valves for their advanced design[J]. Journal of Mechanical Science&Technology,2008,22(10):1998-2005.
[6]王鹏飞.油压锥阀阀口空化流动数值模拟[D].兰州:兰州理工大学,2016.
[7]王黎,偶国富,郑智剑.高温高压差液控阀空化和空蚀的数值分析[J].液压气动与密封,2013,33(6):40-43.
[8]王海彦.流体数值计算方法与实例[M].北京:中国铁道出版社,2016.
[9]朱礼,冯振飞,何荣伟,等.并联细通道夹套内流量分配、流场及阻力特性研究[J].广西大学学报(自然科学版),2016,41(3):847-856.
[10]胡坤. ANSYS ICEM CFD工程实例详解[M].北京:人民邮电出版社,2016.
[11]杨帆,陈伟政,唐学林.空化流动研究进展[J].流体机械,2009,37(11):36-41.
[12]金浩哲,陈小平,郑智剑,等.液控调节阀空化与冲蚀仿真模拟与分析[J].中国科技论文,2016,11(10):1119-1123.
[13]刘佳,何庆中,刘晓叙,等.超(超)临界机组主给水调节阀内部空化流场模拟[J].热力发电,2017,46(2):88-93.
[14]刘桓龙,李惟祥,柯坚,等.液压锥阀空化特性的计算与分析[J].液压与气动,2012,3(9):3-6.