Technical Innovation Of Coal-fired Boiler Control System

The combustion process of coal- fired boiler is a multi- variable system with severe coupling, nonlinearity, time variation and large disturbance. The wind volume, change of blast volume, heating load, parameters of coal supply and ambient temperature has a direct impact on the combustion system. Boiler combustion control not only directly affects the stability of the boiler heating conditions, but also to energy saving, environmental protection, improve the chain furnace thermal efficiency is of great significance.This paper studies the coal- fired boiler house was built in 2001, the same year put into use, the heating area of 1 million 620 thousand square meters. The original control system used in the coal fired boiler room is the TDC3000 system which is produced by the Honey Well Company. On-site control cabinet adopts Siemens PLC control cabinet, the cabinet adopts a multi- layer overlay wiring mode, field operation and data display the manipulator hand operating adjusting digital display device and a table. Communication mode of coaxial cable for DCS system. To meet the production needs of the original control system.However, with the increase in the use of equipment, the problem gradually emerged, in recent years, the DCS control system of coal- fired boiler room frequent failure, and the failure is mainly concentrated in the following parts:1, PLC control cabinet wiring aging, the multi- layer wiring mode and lead to failures occur in the heating period, there is no enough operation space, only to shut down the equipment necessary for the maintenance of;2, hand operator and digital display table failure rate increases, and the number of damage is relatively large, if the replacement, the cost is relatively large;3, PLC control cabinet CPU often alarm, can not communicate with the host computer, crash prone, and part of the cabinet I/O module channel has been damaged.In this paper, based on the transformation of the original control system, through the analysis of the characteristics of the boiler, the boiler research process, combustion system, boiler control system configuration, I / o point layout, logic configuration of major automated information, of the control system were in detail and summary analysis, det ailed system configuration, hardware and software selection, programming software, configuration software design of data acquisition, communication, software programming, monitoring, alarm, historical data query function of the control system to the goal o f optimization and stability control.