DCS system fault drill alarm procedure:
The inspection personnel discovered the fault and promptly reported it to the team leader. The computer team leader reported to the maintenance team director: "Han Jianling, an inspection personnel from the computer team, discovered a network fault in the DCS system A of Unit #6 during her inspection."
The computer team leader reported to the maintenance team director. The maintenance team director then reported the on-site situation to the plant's production technology department, safety supervision department, deputy general manager of operations, and chief engineer.
The maintenance team director instructed the deputy director, team management personnel, and shift leaders to quickly organize personnel, carrying tools, spare parts, and supplies, and assemble at the exercise site (the electronics room of Unit #6).
Upon arriving at the control room, the maintenance supervisor first informed the shift leader and duty manager:
1. The thermal control team is now assembled to conduct an emergency drill for DCS system failure. The drill involves handling a single network failure in the DCS system of Unit #6. All operator stations and control stations are operating normally.
2. During the exercise, operators need to focus on monitoring the FSSS, DEH, furnace negative pressure, and steam drum water level screens according to the actual situation. No operation is required from the operators.
3. In actual working conditions, if the system encounters a problem, manual operation is required until an emergency shutdown is initiated.
Exercise scene:
In the #6 generator set's electronics room, the personnel participating in the exercise have assembled and lined up.
The exercise commander-in-chief, the maintenance team leader, announced:
"Today's exercise is: a single network fault handling drill for the DCS system of Unit #6."
Safety Precautions
• Strictly adhere to the relevant regulations of the electronics room management system and turn off your mobile phones when entering. • This exercise is a simulated real-world exercise. All commands and reports issued during the exercise will use professional terminology, preceded by "exercise," to prevent any appearance of impropriety. • During the exercise, all participants must obey unified command. For operations required in actual work, only verbally describe the troubleshooting steps and methods; do not actually operate the equipment to avoid misoperation.
The commander-in-chief issued the order: The DCS system network failure emergency response drill officially begins.
The maintenance team leader instructed the computer and instrumentation control team leaders: "During the exercise, the instrumentation control and computer teams will check whether the DPU control stations of the FSSS, DEH, and DCS systems of Unit #6 are normal; check the working status of the network switches of each system, and whether the connecting cables are normal. We will investigate the cause of the A network fault as soon as possible."
The computer team and the instrumentation and control team, along with two members of the work team, logged into the system engineer station under the supervision of the on-site safety supervisor to check the system DPU and network working status.
Computer Class Leader: "Drill: All DPUs and workstations in Unit #6 are functioning normally. Inspection revealed an alarm on the A1 network switch, confirming a fault in the A1 network switch."
The instrumentation and control team leader reported to the exercise commander: "During the exercise, after inspection, all network switches of the FSSS and DEH systems of Unit #6 are working normally."
The maintenance team leader instructed the computer team leader: "Perform a drill, prepare the network switch, and process the work order to replace the A1 switch in the DCS system of Unit #6."
The computer class leader instructed Hua Zhijun, a member of his team, to process a work permit: "During the exercise, Hua Zhijun will process a work permit for replacing the A1 network switch in the #6 unit's DCS system."
The computer class leader and staff ran out of the #6 unit's electronic room to process work permits.
One minute later
The computer team leader and staff ran into the electronics room of Unit #6, with the computer team leader holding a network switch in his hand.
The computer class leader reported to the exercise commander: "The exercise work permit has been processed, and the spare network switches are in place."
The general commander instructed the deputy director: "During the exercise, please have the operators closely monitor the FSSS, DEH, furnace negative pressure, and steam drum water level screens, and handle them manually if necessary."
The deputy director walked out of the electronics room and explained the situation to the operators.
One minute later.
The deputy director went into the electronics room and reported to the commander-in-chief: "The exercise is underway, and the operators are ready to replace the network switch."
The commander-in-chief arranged for the computer squad leader to "perform a drill" and begin replacing the network switch.
The computer team leader instructed Han Jianling to monitor the system's self-test screen: "Report any abnormalities immediately and stop the switch replacement work."
The computer class leader assigned Hua Zhijun, the person in charge of the work, and Han Hui and Han Jianling, members of the work team, to begin implementing the replacement steps in accordance with the established specific replacement procedures, methods, and safety measures.
Han Jianling sat next to the computer monitoring the DCS self-test screen.
The personnel replacing the switch begin replacing the switch, describing the actual operation verbally (similar to announcing an operation ticket):
1) Disconnect the power supplies P6A1 and P6A2 of the DCS system A1 switch;
2) Unplug all network cables from switch A1;
3) Disconnect the power cord of the A1 switch;
4) Remove the faulty switch and replace it with a new one;
5) Connect the power cord to the new switch and power it on;
6) Insert all network cables for this switch.
7) Check the system network "self-test".
Safety measures:
1. Maintenance personnel must replace network system switches under the supervision of a designated person.
2. When disconnecting the power to switch A1, make sure that the power switch is the one for this network switch.
3. Before disassembling the switch, a power test must be performed to confirm that the switch is de-energized.
4. Use the correct and qualified tools and equipment when disassembling the switch.
The computer class leader reported to the exercise commander: "The exercise has been completed. The replacement of the A1 switch in the DCS system of Unit #6 has been finished. The network has been restored. The control system of Unit #6 is working normally."
The commander-in-chief instructed the deputy director: "Drill, confirm system is back to normal." The deputy director, after confirming, reported to the commander-in-chief: "Drill, system normal."
The commander-in-chief assigned the computer squad leader to terminate the exercise work order, and the squad leader assigned the person in charge, Hua Zhijun, to terminate the work order.
The on-site commander announced: "The single-network failure drill of the DCS system for Unit #6 has ended."
