Water and steam pipeline oxygenation control method for power plant

Abstract

The invention discloses a power plant water and steam pipeline oxygenation control method for power plant, which mainly comprises the following steps of: dividing a pipeline water flow value into a plurality of sections, and setting a maximum opening degree value ai% for each water flow section; comparing detected pipeline water flow with all section values one by one, and determining the section where the pipeline water flow locates; calculating PID (Proportional Integral Derivative) control quantity according to a detected oxygen content signal in water and a control target value; and comparing a PID control signal with the maximum opening degree value ai% of oxygenation adjustment in the section. If the PID control signal is less than the maximum opening degree value ai% of the section, then the oxygenation adjustment opening degree equals to the PID control signal; if the PID control signal is not less than the maximum opening degree value ai% of the section, then the oxygenation adjustment opening degree equals to the maximum opening degree value ai%. Oxygenation adjustment becomes finer along with the increase of flow sections, and the technical problem that oxygen content of feed water or condensed water oscillates or deviates from the adjustment target value is solved.

Description

technical field [0001] The invention relates to an anti-corrosion control method for water and steam pipelines in a power plant, in particular to an oxygen addition control method for water and steam pipelines in a power plant, and belongs to the technical field of power generation equipment. Background technique [0002] The corrosion of water and steam pipelines in thermal power plants has always been a major hidden danger that threatens the safe and reliable operation of power plants. In order to prevent and alleviate the corrosion of water and steam pipelines in supercritical and ultra-supercritical thermal power generating units, it is necessary to add Appropriate amounts of oxygen and other agents. According to relevant studies, it is found that the amount of oxygen added should not be too much or too little, and the oxygen content in water should be kept at 50-150μg / L. Due to the unstable water quality and quantity of the unit, in order to keep the oxygen content in ...

AI Technical Summary

Problems solved by technology

[0004] However, due to the long water and steam pipelines between the sampling point of the water oxygen content sampling device and the analysis instrument, the hysteresis of the oxygen content signal of the sampling device is relatively serious, especially when the water quality and water volume change, resulting in adjustment accuracy. Unstable, it is easy to cause the oxygen content of feed water or condensed water to oscillate or deviate from the adjustment target value

[0005] The utility model patent with the patent number 200920068184.X and the name "Multi-channel Parallel Combination Power Plant Boiler Feed Water Automatic Oxygenation Device" discloses a technical solution for connecting several unit channels in parallel to form different combinations of opening and closing states, so as to solve the problem of signal Hysteresis leads to regulation instability problems

However, this solution needs to set up multiple unit channels and equip multiple solenoid valves and throttling components, which increases the cost of manufacturing or transformation and the workload of future maintenance

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