汽轮机最有利真空循环水泵变频驱动控制系统  

A Variable-frequency Drive Control System of a Circulating Water Pump for Allowing a Steam Turbine Unit to Operate at an Optimum Vacuum

作　　者：张承慧[1] 程金[1] 夏东伟[1] 

机构地区：[1]山东大学控制科学与工程学院,山东济南250061

出　　处：《热能动力工程》2004年第1期81-84,共4页Journal of Engineering for Thermal Energy and Power

基　　金：山东省自然科学基金资助项目(Y2 0 0 1G0 1) ;山东省优秀中青年科学家基金资助项目(0 2BS0 2 0 )

摘　　要：在火电厂中循环水流量大多采用节流调节方式 ,控制效果差 ,不能保证凝汽器工作在最有利真空值 ,而且循环水泵电耗严重。研制了一种循环水泵变频调速控制系统 ,利用PLC(可编程控制器 )设计合理的控制逻辑 ,实现平稳启停和切换 ,保证最有利真空值的实现 ,使汽轮机经济运行。同时分析了汽轮机的经济运行方式 ,给出了最有利真空值的计算原则 ;详细介绍了系统的控制原理、硬件结构及PLC程序的设计 。Currently, thermal power plants adopt in most cases a throttle-governing mode for regulating the flow rate of circulating water. Such a regulating method suffers from poor control effectiveness and is incapable of ensuring that a steam condenser operates at a most favorable vacuum. Moreover, it also results in a high power consumption of circulating water pumps. In view of the above, the authors have developed a variable-frequency speed-governing system, using a programmable logic controller (PLC) to design a rational control logic. This makes it possible to realize a stable start-up, shutdown and the switching-over of the circulating water pumps, thus providing a steam turbine unit with an optimum vacuum for its economic operation. The economic operating modes of the steam turbine unit are analyzed and a method for calculating optimum vacuum values is given along with a detailed description of the system control theory, hardware configuration and PLC program design. Furthermore, some fruitful application results are presented.

关 键 词：火电厂 最有利真空 可编程控制器 循环水泵 变频调速 PID控制 

分 类 号：TM621[电气工程—电力系统及自动化]