Method and system for compensating and controlling main steam pressure by using one-stage extraction steam regulating valve

Abstract

The present invention provides a method and system for compensating and controlling the main steam pressure by using a section steam extraction regulating valve. The method first sets a compensation intensity signal, and performs first-order inertial filter processing on the compensation intensity signal; then, calculates The deviation between the main steam pressure setting value and the main steam pressure feedback value is used to obtain the deviation signal, and the deviation signal is multiplied by the filtered compensation intensity signal to obtain the product signal, and the product signal passes through the PD controller with limiting function Finally, the first-stage extraction control valve opening bias signal is output; finally, after the first-stage extraction control valve opening bias signal is added to the original first-stage extraction control valve automatic signal, the compensated first-stage extraction control valve automatic command is output Signal. The method and system for compensating and controlling the main steam pressure provided by the present invention can maintain the stability of the main steam pressure under the conditions of thermal power generation load and fuel property changes, and has the advantages of good compensation effect and simple on-site implementation .

Description

technical field [0001] The invention relates to the technical field of automation, in particular to a method and a system for compensating and controlling main steam pressure with a first-stage steam extraction regulating valve. Background technique [0002] One of the effective ways to improve the power generation efficiency of thermal power units is to increase the average endothermic temperature of the working fluid cycle. In engineering, this function is achieved through the steam turbine regenerative heating system. The regenerative heating system is equipped with multiple heaters to extract the steam turbine steam in stages for heating step by step. Feed water, so that the circulating working medium is heated from the cold end temperature of about 30 to 50 °C to about 270 to 300 °C, and then absorbs heat from the boiler. In order to ensure the best thermal efficiency, the overall heat exchange method of the heater adopts a "counter-current" arrangement, that is, the ex...

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Problems solved by technology

In addition, due to the rise in coal prices, the coal sources of thermal power units are complex, and the coal quality is complex and changeable, which will also cause combustion disturbances and cause main steam pressure fluctuations.

The large fluctuation range of the main steam pressure itself will have adverse effects on the safe operation of the unit; and the adjustment function of the boiler side controller of the machine-boiler coordination control system will amplify the fluctuation of the main steam pressure, so that the main control output of the boiler will fluctuate more greatly. Drive the fluctuation of boiler fuel volume, feed water flow, and primary and secondary air volume, affect the stability of parameters such as furnace pressure, oxygen volume, intermediate point temperature, and NOX production volume, and reduce the safety, economy, and environmental protection of the unit operation

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