1. DCS system inspection 1. Regular inspection: Make inspections at the specified time twice a day. 2. Do a good job in dust removal: Do a good job of sanitation and cleaning of the appearance of the control cabinet and operation console once a week; Clean the computer, control station, fan and other surfaces in the cabinet regularly once a week; replace the cabinet filter regularly every two weeks. Check the operation of the control cabinet and console fans every day, and replace them in time if they are damaged. 3. Inspection content: 1) Environmental inspection: Operating environment required by the DCS system: temperature 15°C to 28°C; vibration amplitude 3). Check the DCS screen equipment status diagram during daily inspections to determine whether the system equipment, including the node and network status, is operating normally or whether the engineer station and operating station are crashed. If the equipment is operating abnormally, take measures And return to normal in time. In addition, check the historical trend of the operating station and whether the SOE system can normally record the recent historical data, check the temperature compensation value and daily important alarm historical data, so as to find the abnormality of the system equipment in time. 4) Establish a series of management systems for the maintenance and repair of the whole DCS. There should be detailed requirements and regulations on the operating authority, configuration modification, computer software management, system antivirus, etc. that affect system security; DCS signal mandatory, historical data call management, and important Strict management of interlocking input/removal, etc., especially during the operation of the device, in principle, no configuration modification or hardware modification is carried out to prevent accidents in the system and cause the device to stop operating. 5). Regularly check the load condition of each controller, regularly test the CPU load rate, and make sure that the load rate of the central processing unit of all control stations does not exceed 60% under severe working conditions. The central processing unit of the operating station and data management station does not work well. If the load does not exceed 40%, if the test data is close to the upper limit, no additional points or other operations that increase the CPU load are allowed. 6) Check whether the hardware of the control cabinet, control host, monitor, mouse, keyboard, network equipment, power cord, communication line, signal line, etc. is intact. 4. Make roving inspection records 2. DCS system maintenance 1. System backup 1) System software backup: including operating system, driver, emergency boot disk (especially for WinNT system), control system software, Keycode disk (Centum authorized disk), for the shortcomings of easy wear and tear of CDs and floppy disks in actual use, Pay attention to make more backups, and use mobile hard disk, U disk, hard disk and other backup forms to ensure the preservation of the software. Engineering software backup: regularly back up the lower and upper engineering configuration software, control configuration database and control sub-directory files. Ensure that the project files and database files are up-to-date and complete. 2) Hardware backup: The components and key components that are vulnerable and short in service life, such as keyboard and mouse, I/O modules, power supplies, communication cards, various fans, etc., should be backed up appropriately according to the actual situation. 3) Service information: Make contact information including personnel of hardware manufacturers, system design units, and engineering service units; organize the scope and schedule of after-sales services for various products. 2 Preventive maintenance Carry out active maintenance in a planned way, detect and replace bad components in time, and eliminate hidden dangers. It is an effective method to ensure the reliable and stable operation of DCS. Preventive maintenance is carried out once a year by using the equipment overhaul opportunity to grasp the operating status of the system and eliminate hidden troubles, including: 1) Backup of system data Before the power outage, the system configuration software and data should be backed up, and the data should be backed up by special blank disc burning (anti-virus infection) and computer hard disk backup of different stations to ensure the reliable storage of DCS data. And clean up redundant junk files in the computer. 2) Blowing and cleaning of cards After the system is powered off, clean the dust in the computer, the control station cabinet cage, power supply and other components, and check the cabinet filter and cooling fan. After the card number is recorded, the card is pulled out and cleaned. If dirt remains afterwards, use a special cleaning agent to clean it. During operation, the staff must wear an anti-static grounding ring as required. Pay attention to the guide groove when installing the insert card to prevent damage to the card or incorrect position and poor signal contact. After the system is cleaned, the person in charge of maintenance should confirm that the conditions are met before powering on, and should strictly follow the power-on steps. After power-on, the status of the DCS network online equipment should be confirmed and the system hardware equipment should be fully checked, and if necessary, restart Download the controller program. After cleaning, check the operation of the fans, and replace the problematic fans. 3) Grounding system maintenance Check the looseness of the wiring terminals one by one, and perform grounding resistance test records for the system according to the regulations. The grounding resistance test must meet the requirements of relevant standards. The grounding resistance of the distributed control system of the independent grounding network shall not exceed 2Ω. 4) Timely upgrade of software and hardware In actual application of each type of DCS, various problems will always occur. DCS manufacturers are always improving old systems and developing new systems. With the development of software and hardware, they continue to improve their hardware and software technical performance. At the same time, in order to solve the problems of the system in use, especially after 3-5 years, the old specifications or versions of hardware spare parts are eliminated and many factors prompt users to regularly upgrade part or all of the hardware and software. Use the maintenance opportunity to upgrade the system. Three, DCS system fault judgment and processing 1. Fault maintenance content: The system should be maintained after a failure. The key is to quickly and accurately determine the location of the failure point, which mainly includes the following tasks: 1) If the fluctuating data technology does not directly affect each other, it may be that a certain card of the microcomputer is malfunctioning. The relevant self-adjusting system should be switched to manual adjustment immediately. If necessary, go to the site to adjust, and at the same time, notify the microcomputer and instrument personnel to check. 2) Check the working status of the operation station When it is found that a certain operating station is dead, the monitoring screen data is not refreshed, and the adjustment screen does not work, check whether the system alarm indicator on the upper right side is normal, and check whether other operating stations are working normally. If it is normal, only the operating station has a problem. Notify the computer maintenance personnel to repair. If the data of other operating stations remains unchanged, the system communication network is faulty, and the maintenance personnel are immediately notified to check the operation of the network equipment and repair it. 3) Observe the power failure of the operation station If there is no display in some operating stations suddenly, it means that UPS or mains power is cut off, and the computer maintenance worker shall be notified immediately for maintenance. If the operating station with electricity can be monitored normally, the normal adjustment of the control system will not be affected at this time. 4), pay attention to the situation of all power failures in the control station Since all control station equipment is dual-circuit power supply, one UPS and one mains, the probability of this situation is very small. When the control station is completely powered off, the two system alarm red lights on the monitoring screen are on, the communication is interrupted, all the data is not refreshed, all the self-regulating systems are completely out of control, the regulating valve will be restored to the initial state, the air open valve is fully closed, the air closed The valve is fully open. At this time, emergency treatment or parking should be done immediately, and operations should be carried out on site at the same time. 5), pay attention to the situation that all operating stations are powered off At this time, check whether the power indicator of the control station is normal, whether the card diagnostic indicator has a red light or a green light indicates that the card is working normally. If all of the above are normal, you can confirm that the control station is working normally and the self-adjusting system is working normally. The operator cannot see the monitoring screen for the time being, and cannot remotely operate the site, immediately notify the computer maintenance personnel to perform maintenance and go to the site for monitoring. 6). The pressure of the instrument air source of the regulating valve is low or the instrument air is completely cut off. When multiple self-adjusting systems are found to be malfunctioning, the valve position of the self-adjusting valve on the monitoring screen is in the fully open or fully closed position, and immediately check the instrument air pressure. If the pressure is less than 0.4MPa, it is abnormal. Check whether the gas source pipeline is blocked or leaking; if the gas source pressure is less than 0.2MPa, immediately perform an emergency stop. Turn all the self-adjusting systems on the monitoring screen to manual, adjust the valve position of the regulating valve to a safe position, notify the instrument worker to check the air source, and operate on site at the same time, close the stop valves at both ends of the regulating valve, and operate with the bypass valve. In short, when the DCS fails, the operator should master a certain method of discrimination, find the problem early, and deal with it appropriately, which can avoid or reduce the impact on process control. 2. Typical fault judgment and processing 1), operator station failure or crash handling There are many reasons, such as improper operation causing damage or loss of running programs, host hard disk, card failure, abnormal operation of computer cooling fan, and computer software operation failure, etc., which may cause the operator station to crash, in addition to a considerable part of the computer crash It is due to incorrect operations of personnel, such as opening multiple processes at the same time, or performing frequent and too fast click operations on the same operating terminal at the same time, which does not give the computer response time, which leads to conflicts in computer resource occupation and congestion of network communication, resulting in operator stations Not working properly. For the operator to crash, the general method is to restart the computer, run the project file, and log in the user. 2), process channel failure The probability of failure of the process channel is not too much, usually I/O card failure: I/O card failure is generally judged and dealt with through system diagnosis, channel replacement or replacement of spare parts. As for internal components aging or The damage caused by other reasons is generally difficult for thermal control personnel to judge. I/O card maintenance is generally handled by the manufacturer. The current thermal control maintenance personnel cannot perform the same maintenance as conventional instruments. In addition, manufacturers' I/O card manufacturing has formed an integrated trend, so that only spare parts can be purchased. If a component or control equipment fails, sometimes it cannot be directly discovered by the operator. Only after an abnormality or alarm, the thermal control maintenance personnel will be notified to deal with it. In this way, the quality requirements of maintenance personnel and operating personnel must be improved. Operators must introduce in detail the status before and after the failure so that thermal control maintenance personnel can quickly and accurately deal with defects and reduce the expansion of failures. Many manufacturers' products support it in publicity. The card is plugged and unplugged under power. As a controller, safety protection measures must be taken when replacing the I/O card during operation, otherwise it will cause a change in the control state of the system equipment or a large fluctuation in the load. 3) Failure caused by interference Interference will affect the correct display of analog signals, severely affect the accurate adjustment of system parameters, and then affect the safety and economy of the device. Analyze there are many factors that cause interference, mainly because the system shielding and grounding are not solved well. DCS requires single-point grounding. Generally, the shielding layer of the DCS signal cable is grounded on the side of the DCS cabinet, and then connected to the DCS dedicated On the grounding cable, meet the system grounding requirements. However, it is very difficult to truly implement single-point grounding strictly. There are a large number of field signals entering the DCS, and any signal cable shielding layer may have a short grounding in the field. This may cause the entire DCS to actually be grounded not only at one point, but also in the power plant. Due to the limitation of on-site environmental conditions or economic considerations during installation, many DCSs cannot strictly isolate the strong current cables from the control cables. In addition, the interference signal of DCS may be caused by itself. So people pay more and more attention to the grounding problem of DCS, especially in the power industry, the start and stop of high-power electrical equipment will interfere with the control signal of DCS and cause unnecessary failures. In order to prevent interference signals from entering the system, the shielding and grounding requirements and methods must be strictly implemented, and the signal lines must be far away from the interference source. 4), power failure DCS equipment power supplies generally adopt a redundant configuration design. One power supply failure and the other should be able to switch and automatically switch in time to ensure continuous and uninterrupted power supply to the DCS. However, there are still many abnormal cases of DCS caused by such failures as the power supply: Rukong Unreasonable opening configuration causes the power protection to leapfrog. The UPS system that supplies the DCS power supply loses the backup power or the backup battery can not automatically switch in time after the external power supply is lost, the DCS itself power supply board fails, the DCS power supply voltage fluctuates or the voltage reaches the requirements, etc. Hidden dangers are buried for the safe operation of the DCS system, causing the DCS to not work properly. The thermal control maintenance professionals of the garden power plant below strengthen the daily inspection of the system power supply to ensure the normal operation of the backup power. And focus on gradually improving the measures to prevent power fluctuations and solving the problem of timely switching and self-switching of standby power. Stainless Steel Stretch Plate,Stainless Steel Plate With Holes,Stainless Steel Plate Anti Slip,304 Stainless Steel Stretch Plate ShenZhen Haofa Metal Precision Parts Technology Co., Ltd. , https://www.haofametals.com