Advanced control method for thermal power unit boiler turbine coordination system

Abstract

The invention provides an advanced control method for a coordination system of a boiler and a steam turbine of a thermal power unit, which applies advanced dynamic feedforward technology to the feedforward design of a main control system of the boiler so as to effectively accelerate governing speed of a boiler load command in a load varying process of the unit. In the load varying process of the unit, oscillation tendency of the main control system of the boiler can be inhibited through reducing integral action of a regulator. In the main control system of the steam turbine, a unit load command N0 is subjected to inertia LAG time-delay, and protection design is carried out on main steam pressure. The method ensures that the boiler and the steam turbine can operate under a more coordinated mode and ensures that the thermal power unit has faster ascending and descending speed of load and more stable variation of the main steam pressure, wherein the ascending and descending speed of the load of the unit reaches 3.0 percent Pe / min in actual application, the main steam pressure is stable without overshoot, and the pressure deviation is in an acceptable range.

Description

technical field [0001] The present invention relates to an advanced control method for a thermal power unit boiler and steam turbine coordination system, in particular to a method that adopts advanced dynamic feedforward technology, variable integral technology, etc. to realize rapid and stable adjustment of thermal power unit boiler load instructions and make boilers and steam turbines more coordinated The advanced control method belongs to the field of thermal power engineering and automatic control. Background technique [0002] Distributed control system DCS is commonly used in thermal power units, and the control level and adjustment quality of the units have been significantly improved, but one of the most critical control systems in many power plants (the coordinated control system between boilers and steam turbines) has not achieved ideal control. Quality, the main problem is that the load rise and fall rate of the unit is slow and the pressure fluctuates greatly. Du...

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Problems solved by technology

[0002] Distributed control system DCS is commonly used in thermal power units, and the control level and adjustment quality of the units have been significantly improved, but one of the most critical control systems in many power plants (the coordinated control system between boilers and steam turbines) has not achieved ideal control. Quality, the main problem is that the load rise and fall rate of the unit is slow and the pressure fluctuates greatly. Due to the unreasonable coordinated control scheme of some units, the actual load rise and fall rate of the unit is only about 1% Pe / min, and in During the load changing process, the main steam pressure oscillates and fluctuates above 0.8Mpa, which causes large fluctuations in other important parameters of the unit, such as main steam temperature, boiler drum water level, furnace negative pressure and oxygen content.

PROFI has been successfully applied in individual power plants in China. The unit’s load lifting rate reaches 3.0% Pe / min, and the maximum fluctuation of main steam pressure is about 0.3-0.4MPa. Although Siemens’ new coordinated control system has excellent performance, it is very expensive , and its core technology is completely confidential

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