A Feedwater Flow Control Method Adapting to Rapid Load Fluctuation

Abstract

The invention relates to the technical field of water supplying control of supercritical units, and specifically relates to a rapid load fluctuation adapting type water supplying flow rate control method. The method is characterized in that the main steam flow rate is treated as a main input signal of water supplying control; the difference between target load of the unit and the target load afterspeed limitation, the deviation between the target main steam pressure and the actual main steam pressure, and the deviation between the target temperature and the actual temperature of an outlet ofa separator are overlapped and act on the set water supplying flow rate value; the coal quantity change and the water supplying quantity change are relatively independent; and intermediate point temperature deviation is added to correct the water supplying quantity. According to the method, sufficient water supplying flow rate and pressure are supplied by a water supplying system in running, so that the problems such as large main steam pressure fluctuation and high overshoot of a supercritical pressure circulating fluidized bed boiler can be solved; the cooling water quality of all heated surfaces and the power circulating stability of water in water cooling walls are protected; and the unit can work in an area under a pressure setting working condition. Therefore, the purpose of increasing the economic benefit of the unit is achieved.

Description

technical field [0001] The invention relates to the technical field of feedwater control for supercritical units, and more specifically, relates to a feedwater flow control method that adapts to rapid load fluctuations. Background technique [0002] The power grid monitors the frequency fluctuation of the power system in real time and adjusts the output of the generator in time through ACE to ensure the real-time balance of power supply and demand. As an important link in the real-time control of the power grid, ACE is responsible for the safe and stable operation of the power grid, frequency stability, tie-lines, and power assessment. . With the rapid development of my country's economy and the rapid growth of electricity demand, the installed capacity of thermal power is also growing rapidly, requiring new units to quickly respond to ACE load changes to ensure stable grid frequency. Among the newly added units, supercritical units are the main models. Supercritical units ...

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Problems solved by technology

[0003] In order to overcome the deficiencies in the prior art, the present invention provides a feedwater flow control method that adapts to rapid load fluctuations, aiming at problems such as main steam pressure fluctuations and large overshoots of supercritical circulating fluidized bed boilers. Establish sufficient water supply flow and pressure to protect the cooling water volume of all heating surfaces and the stability of the hydrodynamic cycle in the water-cooled wall, ensure that the unit works in the area of ​​the pressure setting value, and achieve the purpose of improving the economic efficiency of the unit

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