Datang Sanmenxia Power Generation Co., Ltd. Phase II 600 MW units have increased significantly in recent years in the number of card and CPU failures, and the cost of CPU replacement is high, the risk of replacement process is high, increasing the workload of daily maintenance, seriously threatening the safe and economic operation of the unit. After many aspects of analysis, it is known that a large amount of ash accumulated in the CPU and card parts of the controller, resulting in the module, CPU, card heat dissipation is not smooth. Since the second phase was put into operation, due to insufficient experience and technical support, there has been no comprehensive ash removal for the power outage of the controller.
Finally, after a long period of research and analysis, a program was compiled to clean the controller completely, and obvious results were achieved. Hitachi H5000M control system often appears the phenomenon of valve feedback fluctuation in recent years. After checking, it is finally caused by the channel fault of the card, and the failure frequency of the card channel is getting higher and higher. The CPU fault of the controller occurs, which causes the single network operation of the DCS system and seriously threatens the safe and economic operation of the unit. Frequent replacement of cards and CPU costs too much, and the risk factor is relatively large. Through analysis and research, the controller’s long-term ash accumulation is the direct cause of damage to electronic components in the controller. Therefore, without precedent and technical guidance, the controller is completely blackout and ash removal. Backup the data of the historical station: open the maintenance tool of the historical station; click on “configuration data backup and recovery”; select the folder specified by E disk; click on “full selection”; click on “backup”; after backup, use CD-ROM to record, indicating the number, content and time of the unit. Forms should be drawn up to record the progress and avoid missing items and heavy items. Check the power supply, CPU, cabinet alarm of each controller if there is any abnormality, record and deal with the abnormal situation, if the fault can not be eliminated, then suspend cleaning. Check whether the systems and equipments in the controllers are out of operation, make safety measures for the equipments that are not out of operation, and give the operators a safe account. AO measurement points in MC1 controller “adjust the output power”, which is the output power to the power grid, is the basis for power grid settlement. When soot blowing, thermostatic element it is necessary to contact the electrical secondary specialty to do a good job of safety measures (signal generator can be added with a suitable signal). The SC3 controller includes a turning device, a top shaft oil pump, a sealing oil pump and an internal cooling water pump. Before the turning device is out of operation, because the oil level parameters of the relevant oil system can not be swept by SC3 controller, the turning device should contact the operator to replace hydrogen in the generator after the shutdown, and stop the sealed oil pump to sweep after the completion of the replacement. The compressed air pipeline connecting the second stage centralized control room to the channel of #4 furnace.
The compressed air used for cleaning must be dry, water-free and oil-free. The pressure control should be controlled at about 0.05 MPa. The vacuum cleaner used for cleaning must have enough power to suck up the raised dust in time. Prepare anti-static wrist. For equipment with anti-static requirements, anti-static measures must be taken during overhaul. Workers must wear anti-static grounding wristband, and try not to touch the circuit part. Disassembled equipment should be placed on the anti-static board (non-anti-static board should be replaced by clean plastic cloth). Each time a controller is cleaned, the next controller is cleaned after the completion of the cleaning. The power failure of two controllers which are not adjacent to each other at the same time will cause all DCS measurement points to be unable to be monitored; the CPU with battery purge will cause the loss of logic configuration in the CPU. Make detailed and accurate records of the cabinet, slot number and jumper settings of each module to be cleaned.
All markings of power supply, CPU, card, cable plug, bridge and cable plug are named after the cabinet number at the beginning. The power supply is named as: 04A1, 04A2, 04A4, 04A5; 04B1, 04B2, 04B5, 04B6; 04C1, 04C2, 04C5, 04C6 (the number of empty slots is also counted). Card name: 04D6, 04D7, 04D8, 04D9, 04DA, 04DB, 04DC, 04DD, 04DE, 04DF, 04DG. Optical fiber naming: 4DD0D1-A, 4D0D1-B, 4DD2D3-A, 4DD2D3-B (according to the location of the site installation, mark the arrow to indicate the direction). Flat connection cable naming: 4D-6S, 4D-6T; 4D-7S, 4D-7T; 4D-8S, 4D-8T; 4D-9S, 4D-9T; 4D-AS, 4D-AT; 4D-BS, 4D-BT; 4D-CS, 4D-CT; 4D-DS, 4D-DT; 4D-ES, 4D-ET; 4D-FS, 4D-FT; 4D-GS, 4D-GT.
Fan named 04 cabinet fan, cabinet front and rear filter screen named 04 cabinet front and 04 cabinet rear. After checking the mark correctly, switch the power module to the OFF bit, confirm that the power module is out of power, stop the two power supply of the controller at the terminal row of the cabinet power supply, and hang the warning sign of “No Closing, Someone Working”. Pull out the communication lines and wiring of DPU and I/O cards, then take down the power supply, DPU and I/O cards, and place them on the dry and clean plastic cloth according to the classification of I/O stations. Cleaning die, cooling fan, filter and other components; after cleaning, check its appearance should be clean and ashless, no stain, no obvious damage, no bending and fracture of pins and golden fingers, all components should be installed firmly, jumpers and pins should be set correctly, fuses are intact, models and capacities accurate. Cleaning the cabinet, trough frame and terminal board with a vacuum cleaner. After the cleaning and inspection of the die, the cabinet, rack and slot are cleaned, the power supply, CPU and card are restored according to the marking of the die. When restoring, the card must be in place accurately before it can be pushed into the slot by force.
When the die is in place, fix the screw or lock firmly. After the module is in place, the optical fibers, flat connecting cables, bridges and other equipment are restored in turn.
Put the switch of CPUA and CPUB to OFF bit. After checking the correctness of the card and the connecting cable, after removing the “No Closing, Someone Working” card, the two power sources in the power supply line of the controller are confirmed to be normal, and then the power supply of the power module is transferred to ON position in turn. Put the CPUA switch to ON bit, and after the CPUA running light indicates normal, turn the CPUB switch to ON bit, and observe whether the CPUB running indicator and tracking indicator show normal. After power transmission, check the power supply indicator, CPU, card indicator whether normal, abnormal immediately check processing; check whether the configuration data is correct, whether the screen display is abnormal. Check whether the logic operation of the controller is normal at the engineer’s station, if the logic of the controller is not downloaded properly (Hitachi Controller is strictly installed to download the operation file package to execute when downloading).
_Lower installation is completed, each IO module is signal driven and recorded. After all cleaning, check the indicator lights and fans in the cabinet; check the equipment monitoring screen and the network connection of the controller; check whether the control configuration is normal or not, whether the mandatory and setting values in each control are operating normally; check whether the network transmission points between the controllers are normal. If there is any abnormality, it should be dealt with immediately according to the abnormal situation.
In the case of CPU failure of RCI controller, the power supply of FSS2 controller is stopped, which makes all measurement points of DCS system unable to be monitored. Solution: After replacing the CPU of RCI controller, it returns to normal. Preventive measures: Two controllers that are not adjacent to the network can not be cut off. After the FSS2 controller has been purged, all the cards in the expansion cabinet 2 are reported to be faulty. Processing method: The faults still exist after the card in expansion cabinet 2 is plugged online; the faults still exist after UD is plugged in expansion cabinet 2. The running lamp of communication card in expansion cabinet 2 does not flicker (this lamp flickers normally). The flat cable connecting the communication card in expansion cabinet 1 and communication card in expansion cabinet 2 is still abnormal after replacing.
After replacing the communication card of expansion cabinet 1, the card in expansion cabinet 2 shows normal. Check the bending of the golden finger in the slot where the communication card of the expansion cabinet 1 communicates with the expansion cabinet 2. Because there is no spare parts, the communication card in the expansion cabinet 2 (because the communication card in the expansion cabinet 2 uses only one slot) will be replaced with the communication card in the expansion cabinet 1.
Display normal after replacement. Preventive measures: In the process of soot blowing, take and place lightly. When inserting and unplugging the card, the card must be in the slot, and exert moderate force at the same time. After the ATC controller sweeps, the card in the slot of A card is reported to be faulty.
Processing method: After on-line plug-in and pull-out, the display is normal. Precautions: When inserting and unplugging the card, the card must be in the slot and exert moderate force. The flat cable of the card should be inserted in place, and the locking device should be in the locking position.
After the SC5 controller is purged, the card in the 9 slot of the expansion cabinet is reported to be faulty. Processing method: When the card is pulled out, a bend of the golden finger is found in the card slot. After correction, the online insertion shows normal. Preventive measures: In the process of soot blowing, take and place lightly. When inserting and unplugging the card, the card must be in the slot, and exert moderate force at the same time. When FSS4 controller soot blowing, the CPU does not carry battery soot blowing, and the CPU can not run after recovery. Processing method: The master-slave simultaneous downloading of FSS4 controller is performed, and the CPU runs normally after downloading. Preventive measures: CPU soot blowing needs to be purged with batteries. After the power failure of MC1 controller, the outgoing power of Datang Sanmenxia Power Generation Co., Ltd.
suddenly showed a bad point, which made the power grid unable to accumulatively calculate its power generation. Processing method: To check the role of this point, in order to regulate the output power, it is the outgoing power, and is also the basis for the grid to measure and settle the electricity price. Contact the electrician to explain the power grid, and immediately purge and restore the operation of the controller. And further improve the soot blowing scheme. Preventive measures: When soot blowing, coordinate with electrical communication, and replace this signal with signal source. Because Hitachi H5000M system runs for a long time, it causes the ash accumulation in the control cabinet and CPU, and causes the faults of the card and CPU from time to time. Regularly organize the comprehensive ash removal of the controller, and do a good job of preventive measures to avoid man-made damage to the card and CPU, and avoid logical loss, which are the main points for attention in ash removal. The specific steps of ash cleaning and the abnormalities in the process of soot blowing are provided in the hope of providing references for brothers.