Sampling device for flue gas in close-to-wall zone of boiler water wall

Abstract

The invention relates to a sampling device for flue gas in a close-to-wall zone of a boiler water wall. The sampling device is provided with a shell; the cavity of the shell is a flue gas channel; and two sides of the flue gas channel are respectively provided with a flue gas inlet and a flue gas outlet. The sampling device is mounted in a heat-insulation layer located at the unexposed-to-fire side of the boiler water wall; a sampling port mating with the flue gas inlet is formed in a fin of the boiler water wall; and the flue gas inlet is mounted on the sampling port via the unexposed-to-fire side of the boiler water wall and communicated with the boiler via the sampling port. The sampling device provided by the invention has the beneficial effect that the problems of burning loss and obstruction of a flue gas sampling probe (gun) and obstruction of a flue gas sampling pipeline are overcome.

Description

technical field [0001] The invention relates to a monitoring and prevention technology for high-temperature corrosion of a water-cooled wall of a coal-fired power plant boiler, in particular to a flue gas sampling device near the wall of the water-cooled wall of a coal-fired boiler furnace, belonging to the technical field of electric power and power engineering. Background technique [0002] In recent years, with increasingly stringent environmental protection requirements, especially the continuous improvement of NOx emission standards for thermal power plants, coal-fired power plants have implemented NOx control technology transformation, and the mainstream technology adopted is low-nitrogen combustion technology + SCR flue gas denitrification technology. Although the strong reduction zone in the furnace formed by the boiler's low-nitrogen combustion technology organization can reduce NOx emissions, it intensifies the high-temperature corrosion of the boiler water wall. ...

AI Technical Summary

Problems solved by technology

[0007] Due to the high furnace temperature, strong radiation heat transfer, small flue gas sampling flow rate, and poor cooling effect, the flue gas sampling probe installed on the water wall, especially the probe inserted into the furnace, is extremely easy to be burned.

Once the flue gas sampling probe is burned, it will lead to poor sealing and leakage, resulting in distortion of measurement results

In addition, the front end of the burnt probe is melted and deformed, which will lead to blockage of the front-end sampling pipeline, and such blockage cannot be solved by conventional backflushing and other measures, resulting in the system not working properly

[0008] (2) The flue gas sampling port and flue gas sampling pipe Louis blockage

Due to the small size of the fins of the water wall (generally width <20mm), the diameter of the opening is generally small, and it is very easy to be blocked by the molten unburned ash in the furnace

In addition, since most of the technical filter devices are installed in the flue gas sampling pipe at a certain distance from the sampling port, although the system is equipped with a backflushing device, the flue gas sampling pipe is still particularly prone to blockage

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