| In recent years, as China's economy has sustained rapid and stable development, at same time China's iron & steel industry also has entered a rapid development. Baosteel as the most completive iron & steel company in china, will through new project and digging existing equipment's potentials to expand production capacity and enhance competitiveness. Several BF (Blast Furnace) will expand production by improved the BF capacity. Blower, as the main equipment for BF, also will raise the output air pressure and flow. Then the blower's OP (Operation Point) will breakthrough the preset anti-surge control line, entered the high pressure and risk region. The original control system can not guarantee blower's OP in the high security, optimized control system is necessary, ensure the blower supply the air stable and safety.This paper will focus on optimizing the blower control system, analyzed and researched the control system from signal acquisition, signal analysis, PID control, control valves etc. Optimized the control mode and updated the PID loop and security for blower control system, so as to enhance the control system automation. Meet the blower running in high region with reliability, security, stability.The optimization and transformation content consists of the control system (DCS) hardware, application software (control mode) and the communications networking.The optimization for DCS hardware.Computerized digital DCS has been applied for the control and instrumentation of blower system. Adopted Yokogawa Company's new product CS3000 the mainstream of today's major DCS control system as a main control system framework for the realization of blower the main functions: start, regulation, stop, security, protection.With different control function and security level, then we adopted various scanning rate, guarantee the FCS Controller's CPU loading rate below the security value. The important loops used SOE card at 1mS high-speed scanning, recording and recalled the events of the accident; such as anti-surge PID control loops at high-speed scanning; the normal instrument and PID control at normal scanning.Used advanced, flexible programmable YS series controllers as CS3000 backup device in anti-surge etc six important loops, realized redundant control. In case of DCS failure, important operations such as stator blade positioning, blow off valve operation and anti-choke valve operation and so on shall be transferred automatically to YS controllers mounted on the blower control desk without disturbance. Vice versa; then ensured the blower safety and reliability.Through Updated signal acquisition devices and the control valve, optimization the whole control loop devices. We special analyzed the oxygen control valve found the cylinder capacity is too small to drive the valve. Then affect the oxygen flow control. After a serial research and study, at the end redesigned the cylinder for the control valve, then solved the oxygen flow control stability.The optimization for DCS application software (control mode).The software optimization measures is redesign anti-surge control loop besides realized the blower normal control such as air constant flow control, constant pressure control, anti-choke control…etc.The original anti-surge control line is static. Used CCC (US Compressor Control Corporation) sophisticated algorithm, changes the anti-surge control mode, the new designed line can be dynamic moved before the blower surge. Then expanded operations Blower operate region.We used today's advanced DCS System strategy. According to the definition of the prior configuration, when the control system detected a certain input or output signal circuit fault, then automatic switching to FALL BACK strategy, the controller will hold the output, or suppressed limited action, or Switch to redundancy device.The communications networking.The No.3 blower new control system (CS3000) communicated with YS series controller and Toshiba Electric PLC and other Blowers'control system such as CS3000 andμXL.First, CS3000 connected with YS series controller by MODBUS (RS485 communication protocol). The new system achieved the dual and redundant control functions. During the study stage, we found that communication conflict between SOE card and MODBUS communications card (ALR121) at Yokogawa Corporation FCS controller station. At the end, we delay MODBUS communication card's scan cycle, and then solved the problem.Second, CS3000 connected Toshiba PLC (using the synchronous motor device control) through Yokogawa Corporation's FA-M3 PLC, which acts as a gateway converts Toshiba PLC's FL-NET protocol to ETHERNET protocol.Third, CS3000 (No.3 blower) connected with another CS3000 (No.5 blower) through BCV (bus converters) and multi-project software package. And CS3000 (No.3 blower) connected with Yokogawa Corporation early DCS productμXL (No.1, 2, 4 Blowers) through BCV convert the bus protocol from RL-BUS to V-NET. Finally, the operator at one HMI (Human Machine Interface) can, operate and monitor all 5 Blowers, improved labor productivity.
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