Intelligent water wall high temperature corrosion preventing system suitable for large power station boiler and method

Abstract

The invention relates to an intelligent water wall high temperature corrosion preventing system suitable for a large power station boiler and a method. The system can be adjusted in real time according to the change of the operating conditions of the boiler to prevent a water wall from high temperature corrosion, operating personnel involvement is not needed, and the high temperature corrosion is intelligently prevented. The system comprises a pressurizing pipeline communicated with an air pre-heater outlet hot secondary air box, a booster fan is arranged on the pressurizing pipeline and is communicated with an annular air box of surrounding a protection wall, the annular air box is communicated with branch air boxes through connecting air boxes, and the branch air boxes are communicated with ventilation grooves in the boiler wall. An air flow adjusting device is arranged on the pressurizing pipeline, and the air flow adjusting device comprises an isolation baffle, a master adjusting baffle, an air flow measuring device and a pressure sensor and further comprises a branch adjusting baffle of the connecting air boxes. An intelligent control system adjusts the opening and closing degree of each baffle in the air flow adjusting device according to the operating state of the boiler, and the air flow is controlled to prevent the water wall from the high temperature corrosion.

Description

technical field [0001] The invention belongs to the technical field of power plant boilers, and relates to an intelligent water-cooled wall high-temperature corrosion prevention system and method suitable for large-scale power plant boilers. This system can obtain Real-time and continuous instructions to maintain the oxidative atmosphere on the wall surface of the water-cooled wall area, effectively avoiding the occurrence of high-temperature corrosion of the water-cooled wall. In this process, no participation of operating personnel is required. It is an intelligent system and method for preventing high-temperature corrosion of the water-cooled wall . Background technique [0002] China is still dominated by thermal power generation at this stage, and coal-fired units are the absolute main force. Due to the increasingly high requirements for environmental protection, new and old units must meet the requirements of low emissions. Among them, in order to reduce the emission o...

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Problems solved by technology

According to literature retrieval and data collection, the current domestic and foreign technologies for the prevention and treatment of high temperature corrosion mainly include: passive prevention, such as the use of spraying technology or higher-level pipes; , this technology was first applied to low-nitrogen burners, but the side wind was attenuated quickly due to the low wind speed and small air volume. Through field measurements, it was found that this technology had very limited effect in changing the atmosphere of the water-cooled wall; it was also used A special wall-mounted wind device, but this type of wall-mounted wind device has low wind pressure and low wind speed, and requires operators to adjust, and there is no specific adjustment basis, and intelligent adjustment cannot be realized. Or when the load is extremely low, the wall-mounted wind device is still in use, which will have a certain negative impact on the stable combustion of the boiler

[0005] According to the mechanism of high-temperature corrosion, there are many factors causing high-temperature corrosion, and it is difficult to eliminate all influencing factors through operation adjustment or other means, especially at present, in order to meet more stringent environmental protection requirements, boilers basically use low-nitrogen Oxygen-deficient combustion in the main combustion area of ​​the burner is unavoidable. Field tests have proved that it is more effective to use the wall-mounted wind to form an oxidizing atmosphere on the surface of the water-cooled wall. Due to the limitation of the wall-mounted air volume, the combustion will be affected if the wall-mounted air volume is too high. If the wall-mounted air volume is too small, an effective oxidative atmosphere cannot be formed on the surface of the water-cooled wall, and it is necessary for the operator to judge and adjust the wall-mounted air device, which increases the operation time. The workload of personnel and prone to human errors, but can not achieve intelligent control

[0006] Through the above analysis, it can be seen that high-temperature corrosion of boiler water-cooled wall tubes is a relatively common problem, which is highly destructive to the boiler and has many influencing factors. The current methods of preventing high-temperature corrosion mainly have the following problems: (1) The control cannot be intelligent It is necessary for the operator to judge and adjust the high temperature corrosion prevention system by himself; (2) The air pressure is low in the method of sticking to the wall, and the effect of changing the atmosphere of the water-cooled wall surface is not obvious

(3) There are many modifications to the water-cooled wall surface, which may have a negative impact on the hydrodynamic conditions of the water-cooling ratio

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