球阀设计大致过程
本科课程设计
题目:过程流体机械课程设计
学院:机械与自动控制学院
专业班级:过程装备与控制工程
姓名:学号:
二O一六年七月
目录
摘 要· ·························································I
第一章 工作原理和设计方法·········································1
1.1 工作原理···················································1
1.2 设计方法··················································· 1
1.2.1 球阀结构··················································1
1.2.2 球阀材料··················································2
1.2.3 阀体················································3
1.2.4 球体················································4
1.2.5 阀杆················································4
第二章 球阀尺寸计算················································6
2.1 阀体······················································· 6
2.2 阀杆·······················································6
2.2.1 阀杆尺寸··········································· 6
2.3 球体尺寸计算··············································· 6
2.4密封比压··················································· 6
2.5球阀转矩··················································· 9
2.6法兰螺栓校核·············································· 10
2.7法兰选型·················································· 11
第三章 数值模拟计算方法········································· 12
3.1 数学模型···················································12
3.2 网格划分···················································13
3.3 边界条件···················································14
3.4CFD使用步骤················································14
第四章 管道内流体模拟结果分析·····································15
4.1 球阀在不同相对开度时的速度分析·······························15
4.2 球阀在不同相对开度时的压力分析·······························16
4.3 球阀在不同相对开度时的流量系数分析···························17
第五章 总结······················································· 参考文献··························································
摘要
本学期过程流体机械,我组所做课程设计为V型球阀。V型球阀属于固定球阀,也是单阀座密封球阀,调节性能在球阀中比较有优势。本设计说明根据已知的球法者及经验对DN100mm,PN 1MPa的球阀进行设计,主要包括了材料选择,结构设计,尺寸计算,强度校核,三维建模,CFD数值模拟分析等。并且,尽量式结构在满足其工艺要求的前提下,降低结构的复杂性。
本设计中,根据老师给定的数据和已知条件进行设计,并根据国家标准和设计手册进行选材。设计期间用到了solidworks进行三维建模,并建立了流道图,用到了gambit进行网格划分,设置边界条件,用fluent进行对不同开度时的流道进行压力和速度分析并获得相应云图。通过以上软件完成对V型球阀的分析计算。并未以后的相应工作打好相应的基础。
关键词:结构设计,尺寸计算,强度校核,数值分析
第一章 工作原理及设计方法
1.1 工作原理
具有与截止阀相同的旋转90度提动作,不同的是旋塞体是球体,有锥形通孔或通道通过其轴线。当球旋转90度时,在进、出口处应全部呈现球面,从而截断流动。球阀的主要特点是本身结构紧凑,易于操作和维修,适用于水、溶剂、酸和天然气等一般工作介质,而且还适用于工作条件恶劣的介质,如氧气、过氧化氢、甲烷和乙烯等。球阀阀体可以是整体的,也可以是组合式的。V型球阀是中央有通孔的球作开关的阀门,传统上分为浮动V型球阀和轴耳固定V型球阀两种。浮动V型球阀的开关球经阀座密封对接在阀体中转动,转动到通孔与通道口对准时为全通,转动到通孔与通道口成一定角度时为全闭。
浮动V型球阀的开关球通过槽与操作阀杆相连,在介质压力作用下,可相对阀杆或阀体浮动在下游阀座上,从而实现关闭密封。轴耳固定V型球阀的开关球通过以阀杆为轴的轴耳固定在阀体上,在介质压力作用下,不可相对阀体浮动,只能通过上游阀座的浮动实现关闭密封。因此,浮动V型球阀的阀座可以是固定阀座,轴耳固定V型球阀的阀座是浮动阀座。总结:V型球阀座的结构和性能可通过阀座的截面基准等边三角形来控制和调整,因此,凡V型球阀座皆可按等边三角截面法设计,首先按结构和性能基本需要确定其截面基准等边三角形,然后以截面基准等边三角形为截面要素、截面成分或截面轮廓确定阀座截面,最后按具体需要选择材料。实际上,按等边三角截面法设计,V型球阀座和开关球一同变得极易标准化,而一旦标准化后,V型球阀座和球的设计仅在于按介质和介质压力简单确定材料。(等边三角形截面法)
1.2 设计方法
1.2.1 球阀结构
1.2.2 球阀材料
球阀材料根据公称压力选用,由球阀设计计算手册查得可选 灰铸铁 HT150。如图示:
阀体选用HT150