| Based on the reconstruction of Nan ding power station #1 unit, this paper generalized boiler, turbine and attaching machine's DCS module and establishment way and configuration characteristic as primary control goal, and carried on the discussion on the new control algorithmusability.2*65MW units of Nan ding power station is piping-main scheme steam extraction and heating unit. They were put into production in 1996.The control equipment adopt DDZ-III type routine control because of the limit of design level and project cost Control mode is one-to-one manual turbine and boiler centralized control. The control system includes DAS system, boiler protection system, turbine protection system, self-regulation system, steam turbine hydraulic pressure regulation system and one-to-one manual control system. Among them, the system of DAS adopts 893 dates collection front-end, the boiler protection adopts Toshiba PLC, the turbine protection system adopts routine relay of hard-wired connection, self-regulation system adopt KMM single loop adjuster, manual control system adopt routine button, the control of steam turbine adopt hydraulic pressure regulation system to adjust rotate speed,power and extraction pressure. Basic principle of Nan ding power station #1 unit reconstruction includes utility, credibility and advance. The reconstruction scope includes MCS, FSSS, SCS, DAS, ECS, DEH systems and synergic system. It involved almost main auxiliary equipment control and loop control. The number of I/O points is 3263.system point could be displayed, given an alarm,history data analyzed,controlled with DCS.After reconstruction complete transforming.it can replace the routine instrument with CRT,perfect supervise cover, keep the main parameter instrument appropriately for reservation, the operating personnel could control unit running and start-stop perfectly through CRT and mouse. The effect after reconstructing:(1) Reducing equipments maintenance expenses and repair piece reserve. If adopting routine instrument it need transducer, distributor and dogmatic table. It only need transducer, input block.(2) Reduce signal transition, improve control system reliability, and record all dates at the same time for the trouble analysis and judgment(3) FSSS system equipment aging. there is no place purchase repair piece,disadvantage to safe operation of equipment.(4) Improve unit control level and precision, lighten labor intensity and personnel number, raise work efficiency and unit economy though DCS (including DEH)reconstruction.The maturity of DCS technical level and reliability realized the application in power plant Under the pressure of competitive price, DCS could raise whole unit competitive ability. |
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