基于PCS7的并列运行锅炉燃烧控制系统

针对并列运行锅炉存在主蒸汽母管压力波动较大和各个锅炉燃烧不稳定的问题,分析了主蒸汽母管压力内、外扰动的形成原因以及影响锅炉燃烧的各种因素,提出了能保持蒸汽母管压力稳定的加前馈的串级控制方案。利用西门子公司的PCS7过程控制系统,实现了并列运行锅炉燃烧过程的自动控制。该控制系统使用Profibus现场总线进行现场站级之间的通讯,而工作站级和现场站级之间的通讯是通过工业以太网环网。生产实践证明,该控制方案设计合理、控制系统使用方便、鲁棒性强,基本满足了并列运行锅炉燃烧过程自动化的要求。

Combustion System of Boilers Running in Parallel Based on PCS7

There are two main problems in boiler running in parallel: heavy fluctuation of the pressure of the main steam mother-tube and the unstability of the combustion of every boiler.Through analysis of the reasons that cause inside and outside disturbances of the pressure of the main steam mother-tube,according to the characteristics of load assignment among boilers running in parallel and combustion control in boilers,cascade control method with feedforward is proposed to counteract the disturbances.Whole automatic control of combustion process is implemented in the basis of the PCS7 process control system.Under the control system,communication among automation stations is realized by using Profibus fieldbus,while automation stations and work stations is connected with industrial ethernet in loop.Practical result illustrates the feasibility of the design method and the system,which is robust and easy-to-operate,as well as achieves the requirements in combustion process automation of boilers running in parallel.