离心泵最小流量保护方案的选用原则  

Principles in Minimum Flow Protection Scheme Selection for Centrifugal Pumps

作　　者：郑伟 王萌 ZHENG Wei;WANG Meng(Beijing Aerospace Petrochemical Technology and Equipment Engineering Co.,Ltd.,Beijing 100176,China)

机构地区：[1]北京航天石化技术装备工程有限公司,北京100176

出　　处：《化肥设计》2021年第2期33-38,共6页Chemical Fertilizer Design

摘　　要：针对工艺流量低于离心泵的最小需求流量时,会出现泵体过热、泵的运行效率降低甚至汽蚀的现象。采取旁路回流管线将足够量的流体循环回泵前储罐的措施,从而保护离心泵。但是,泵出口处与储液罐内存在一定压差,减压时流体会出现缩脉现象,在这个过程中可能出现闪蒸或汽蚀。本文综述了不同类型的离心泵最小流量保护方案,介绍了连续循环系统、控制循环系统和自控回流阀三种保护方案。分析了三种保护方案各自的技术特点、应用范围和费用,探讨了保护方案的选用原则。When the process flow is lower than the minimum demand flow of the centrifugal pump,such problems as overheated pump body,lowered pump operating efficiency,and even cavitation could occur.By using a bypass return line to circulate sufficient amount of liquid back to the pre-pump storage tank,the centrifugal pump could be protected.However,there is a certain pressure difference between the pump outlet and the liquid storage tank,and the fluid will shrink during decompression,and then flash or cavitation may occur.This paper summarizes the minimum flow protection schemes of different types of centrifugal pumps,introduces the following three protection schemes,i.e.continuous circulation system,controlled circulation system and auto-control return valve,analyzes the technical characteristics,application scopes and costs of each protection scheme,and discusses the principles in protection scheme selection.

关 键 词：离心泵 最小流量保护 多级减压 防汽蚀 自控回流阀 调节阀 

分 类 号：TH311[机械工程—机械制造及自动化]