Overview of Soot Blowing Programmable Control System
During the operation of industrial boilers widely used in power, petroleum and chemical enterprises, ash will accumulate on multiple components such as boiler water wall, superheater, economizer and air preheater tubes. Ash deposition will weaken the heat transfer efficiency of pipe walls. In severe cases, coking occurs, shortening service life and even causing equipment damage. Therefore, large boilers are equipped with soot blowers to regularly remove ash and slag on heating surfaces.
The automatic programmable control system for soot blowing adopts PLC as the core control unit to regulate all soot blowing equipment in accordance with on-site process requirements. A touch screen or host monitor is used for equipment status monitoring. Equipped with a remote communication interface, the system realizes full automatic control.
The soot blowing control system effectively improves boiler efficiency, extends maintenance cycles, reduces energy consumption, enhances coal type adaptability and unit availability. It also lowers labor intensity, improves working conditions for operators, and ensures safe and economical boiler operation. The control cabinet can be designed with an explosion-proof positive pressure structure to guarantee safe and reliable operation in flammable gas areas of petrochemical sites.
Composition of Soot Blowing Programmable Control System
The system mainly consists of an operator interface unit (display operation screen or industrial computer), soot blowing interface unit (main control cabinet), power drive unit (power cabinet) and local field devices (long-retractable soot blowers, short soot blowers, air blowers, electric valves, etc.).
The display operation screen is composed of control panels, indicator lights, buttons and selector switches. Installed in the central control room, it allows operators to start/stop soot blowers and view operating status. If adopting the host computer mode, the operator interface unit is an Advantech industrial computer connected to the control cabinet via control cables. All operation interfaces are displayed on the LCD screen, and all operations can be completed by mouse.
The control cabinet collects on-site signals, receives commands from the operator interface unit, and coordinately manages the overall system operation to realize electric control of all actuators. The power cabinet is directly controlled by the main cabinet to drive various soot blowers and electric valves.
Functions of Soot Blowing Programmable Control System
Group Control
According to on-site blower layout, control circuit load and other factors, soot blowers are divided into independent control groups, including: furnace wall soot blower subsystem; superheater, reheater and economizer soot blower subsystem; rotary air preheater soot blower subsystem; inlet steam valve and drain valve control subsystem on soot blowing steam pipelines. The specific grouping can be customized according to actual user equipment conditions. Each group is equipped with independent power and control power supplies, with interlock protection designed in both hardwiring and software to prevent overload of switches and circuits.
Soot Blowing Control
Multiple control modes are optional: automatic sequence control, remote manual control, local manual control, and local steam-free blowing mode. All electric valves on the soot blowing steam pipeline are incorporated into the program control system, supporting remote operation on the control panel and local manual operation on site.
The local steam free blowing mode is only permitted under boiler shutdown conditions for maintenance and commissioning, to prevent equipment burnout caused by dry blowing.
In remote manual mode, any single blower can be started in arbitrary sequence, with interlock protection and manual interruption function available.
In default automatic sequence control, blowers run in numerical order; meanwhile, combined group sequence operation is optional. The system can operate cyclically with preset interval time and supports interlock triggering and manual stop. Pressing the emergency exit button during sequence operation will retract running blowers in advance, terminate sequence control and return the system to standby status. When switched to local mode, on-site manual operation is available.
Interlock Protection
Comprehensive interlock and protection functions ensure stable and safe system operation, including: soot blowing medium pressure protection, control power loss protection, motor overload and short-circuit protection, blower forward/retraction overtime protection, manual/automatic interlock, low medium pressure interlock (operation prohibited), forward overtime emergency retraction interlock, and automatic trip upon faults. Audible and visual alarms will be triggered when faults occur, and corresponding protective measures will be activated automatically according to fault types.
Operation Interface
The host computer adopts an Advantech industrial computer with configuration software. Optional interfaces include: main control panel, manual operation panel, pressure & temperature curve diagram, alarm display, sequence control selection screen, and smoke temperature detector control screen. Dynamic visualization displays the layout and real-time status of valves, pipelines and blowing pipes, together with running time, blowing pressure and system status indicators.
Once an alarm occurs, the alarm window pops up automatically with detailed fault information. Operation records and fault data for the latest 30 days can be stored and queried in the alarm list.
