吹灰器安全阀选型设计方法研究.pdf

分类号
密级
UDC
善中科大
硕士学位论文
吹灰器安全阀选型设计方法研究
学位申请人
李世军
学科专业
工业工程
指?教师
李成刚教授
论文答辩日期_2005年4月28目学位授予日期
答辮委员会主席吴?林评阅人吴?林胡于进刘爱华
华中科技大学硕士学位论文
摘要
吹灰系统安全阀选型设计的重点是安全阀结构选择和排量计算。对于排量计算,
国内外很多规范和标准都提供了一些方法,但不同标准提供的计算公式所得到的计
算结果却差异很大
本文叙述了安全的工作原理和动作过程,区分了整定压力与排放压力在概念
上的差异,明确了用排放压力作为计算压力。分析了杠杆式、弹簧式和脉冲式安全
阀的结构特点和微启式、全启式安全阀的工作原理,归纳、总结了安全阀的设置原
则和选型原则。
分析了安全阙排量计算的理想过程与实际过程之间的差异,明确了安全阀理论
排量、实际排量和额定排量的概念以及排量系数、额定排量系数和减低系数之间的
关系
运用工程热力学和流体力学的基础知识推导了气体、饱和蒸汽和液体等工质的
安全阀排量计算方法。针对国内不同标准中推荐的三种排量计算方法和不同标准中
关于额定排量系数和排放压力的规定,本文进行了详细地比较和深入地分析,并根
据具体的安全阀的厂家资料,应用不同计算方法经过计算、比较各标准推荐的计算
公式的准确性,找到了适合吹灰系统的计算方法。
关键词:安全惻排量计算排放压力选型
华中科技大学硕士学位论文
Abstract
onfiguration selection Flow calculation is a key step safety valve design and
model selection for sootblower system. For Flow calculation there have been various
methods and formula being given in a lot of national and intemational standards. But
different flow calculating formula may bring about different result
This thesis has included depiction on safety valve operating principle and action
process, definition of set pressure and exhaust pressure, and confirms that exhaust
pressure shall be used as calculating pressure, analyzes structures of lever safety valve
spring loaded safety valve and pulse safety valve, as well as operating principle of
slightly-open safety valve and full-open safety valve. It also sums up principles for safety
valve setting and model selection.
Besides, this thesis compares theoretical result from safety valve flow calculation
and actual result, and analyzes the difference and impacts, clarifies concepts of theoretical
flow actual flow and rated flow, sets forth relations among flow coefficient, rated flow
coefficient and derated coefficient and discusses flow calculating methods for workin
media of gas, liquid and saturated steam respectively.
In addition, the thesis compares and analyzes the three flow calculating methods
recommended in several national standards and definitions on rated flow coefficient and
exhaust pressure in different standards Based on the references on specific safety valve
manufacturers, use different calculating methods, compare accuracy of formula
recommended in each standard and get the appropriate calculating method for sootblower
system
Key words: Safety valve, flow calculation, exhaust pressure, Select type.