A Coordinated Control System Calorific Value Correction Method Based on Steam Turbine Efficiency Correction

Abstract

The invention relates to a coordination control system heat value correction method based on steam turbine efficiency correction. For aiming at steam turbine efficiency change, correction is performedon a boiler master control in a coordination control system. The method comprises the following steps of A, correcting a boiler-side heat value correction loop; B, correcting steam-turbine-side efficiency; C, performing exhaust enthalpy calculation based on a generalized radial basis neural network; and D, correcting the output of the boiler master controller according to the heat value. According to the method of the invention, steam turbine efficiency is separated from a boiler heat value correction amount; boiler efficiency and steam turbine efficiency are separately calculated; the presetvalue of the heat value correction loop is changed from a load function to the actual heat load function of the set. The coordination control system heat value correction method has advantages of ensuring a fact that the output of the heat value correction loop is an actual heat value, effectively reducing system fluctuation caused by steam turbine efficiency change, reducing overshoot and improving safety and stability of the set.

Description

technical field [0001] The invention relates to a calorific value correction method of a coordinated control system based on steam turbine efficiency correction. Background technique [0002] The task of the coordinated control system is to make the load of the thermal power unit quickly respond to the external load demand (intermediate load command or operator load command), and at the same time maintain the stability of the steam pressure in front of the unit. The calorific value correction loop is an important part of the coordinated control. Its function is to correct the fuel calorific value when the coal calorific value of the unit deviates from the standard coal, so as to ensure the stability of the coordinated control system. The traditional calorific value correction circuit compares the amount of fuel consumed by the unit with the electrical load, and considers the efficiency of the unit as a whole. When the amount of fuel used deviates from the design value, it is...

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Problems solved by technology

However, with the continuous development of thermal power energy-saving technology, when the efficiency of the steam turbine changes due to changes in the operating point, the shortcomings of this scheme are also becoming more and more prominent.

For example, when the back pressure of the air-cooled unit changes with the change of load and ambient temperature, the efficiency of the steam turbine will change the efficiency of the entire unit, and the calorific value correction circuit will continuously correct the calorific value of the fuel due to the change of the back pressure, resulting in the corrected calorific value in the coordinated control system. The mismatch of the actual fuel calorific value causes the parameters to oscillate during the variable load process of the unit; energy-saving technologies such as steam turbine flow modification, unit flexibility modification, and sliding pressure optimization will also change the efficiency of the steam turbine, resulting in the wrong adjustment of the calorific value correction circuit, causing the main unit Parameter fluctuations affect the safe and stable operation of the unit

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