RELANCE 0-60002-5 PLC模块

典型的主设备选型多为循环流化床锅炉配抽汽式汽轮发电机组，一般为二炉一机或三炉二机，热力系统为母管制。以此为例：

　　锅炉运行控制任务

　　① 自动检测：用检测元件和显示仪表，对锅炉的热工参数(压力、温度、流量等)进行连续测量和显示，并为自动调节和安全保护提供检测信号。

　　② 自动调节：对锅炉运行参数进行自动调整，以适应外界负荷和工质参数的要求，并使锅炉保持在较经济的工况下运行。

　　③程序控制：使锅炉的启、停及运行等一系列操作实现自动化。如系统启动按照引风机、鼓风机、炉排的启动顺序进行。

　　④保护连锁：系统必须具有超压、水位过高、水位过低声光报警以及超压停炉和水位过低停炉热工联锁保护等功能。电气联锁保护是为防止设备在启、停过程中由于操作错误而造成事故。

散控制系统(DCS)是计算机、自动控制技术及网络通讯技术的综合产物。它基于控制分散、危险分散、操作和管理集中的设计思想，采用多层分级、合作自治的结构形式，适应了现代化生产和企业管理的要求。

　　随着我国生产力的不断发展以及我国在生产过程自动化方面科技水平的不断提高，目前我国新建的火电厂普遍都采用了DCS控制系统，以前采用常规控制的火电厂也基本进了DCS改造。随着DCS控制系统的不断发展，性能不断提高价格逐年下降，DCS控制系统的应用范围将越来越广。DCS也逐步开始在小型电厂广泛应用。在我国控制工程网版权所有，小型火电厂基本上为供热机组，主要用于冶金、石化、化工、纺织等行业大型企业的自备电厂及城市供热，大部分属于电力系统外的电厂。

The typical selection of main equipment is mostly for circulating fluidized bed boilers equipped with extraction steam turbine generator sets, generally consisting of two boilers and one unit or three boilers and two units, with the thermal system as the main pipe. Taking this as an example:

Boiler operation control tasks

① Automatic detection: Using detection components and display instruments, continuously measure and display the thermal parameters (pressure, temperature, flow rate, etc.) of the boiler, and provide detection signals for automatic regulation and safety protection.

② Automatic adjustment: Automatically adjust the operating parameters of the boiler to meet the requirements of external loads and working fluid parameters, and keep the boiler operating under more economical conditions.

With the continuous development of productivity in China and the continuous improvement of technological level in production process automation, newly built thermal power plants in China generally adopt DCS control systems, and thermal power plants that previously used conventional control have also undergone DCS transformation. With the continuous development of DCS control systems and the continuous improvement of performance, prices have been decreasing year by year, and the application scope of DCS control systems will become increasingly broad. DCS is gradually being widely used in small power plants. In China, the copyright of the Control Engineering Network is reserved. Small thermal power plants are basically heating units, mainly used for self owned power plants of large enterprises in industries such as metallurgy, petrochemicals, chemicals, textiles, and urban heating. Most of them belong to power plants outside the power system.

Distributed Control System (DCS) is a comprehensive product of computer, automatic control technology, and network communication technology. It is based on the design concept of decentralized control, decentralized danger, centralized operation and management, and adopts a multi-level hierarchical and cooperative autonomous structural form, which meets the requirements of modern production and enterprise management.