Method for reducing ash blocking of rotor of heating surface rotary air preheater

Abstract

The invention discloses a method for reducing ash blocking of a rotor of a heating surface rotary air preheater. When temperature sensors detect that the lowest temperature of surfaces of heat transfer elements in chambers which are located at one side of a rotor cold end is lower than 100 DEG C, an electric signal is sent to an electrical control system through the temperature sensors, the rotating speed of a rotor driven by a variable-speed motor is improved through the electrical control system, and the rotating speed of the variable-speed motor is kept until the lowest temperature of the cold end of the rotor exceeds 100 DEG C. The invention aims to provide the method for reducing the ash blocking of the rotor of the heating surface rotary air preheater, the ash accumulation and the scale accumulation on the surfaces of the heat transfer elements and the inner walls of the chambers can be reduced or avoided, cleaning of the accumulating ash on the surfaces of the heat transfer elements and the inner walls of the chambers is more convenient, the heat exchange efficiency is high, and the service life is long.

Description

technical field [0001] The invention relates to a method for reducing clogging of a rotor of a rotary air preheater on a heating surface. Background technique [0002] The existing rotary air preheater on the heating surface usually includes a shell, in which a cylindrical rotor is rotatably installed in the vertical direction, and a plurality of partitions are arranged in the radial vertical direction in the rotor, and the partitions The plate divides the rotor into several fan-shaped compartments, each compartment is equipped with heat transfer elements, and the right side of the shell is provided with a flue gas channel along the vertical direction, and the flue gas channel passes through the compartments of the rotor in the shell. The lower end of the gas channel, that is, the cold end of the rotor is the smoke outlet, and the upper end of the flue gas channel, that is, the hot end of the rotor, is the smoke inlet. The left side of the housing is respectively provided wi...

AI Technical Summary

Problems solved by technology

However, during the use of the existing rotary air preheater on the heating surface, there will be a certain amount of condensation in the flue gas passing through the flue gas channel, which will condense into a liquid state at a relatively low temperature. When passing through the chamber on the rotor in the flue gas passage, if the temperature of the inner wall of the chamber is low, the condensate will be deposited on the inner wall of the chamber at the lower temperature and on the surface of the heat transfer element. The existence of condensate in the flue gas will cause a large amount of dust to accumulate on the inner wall of the chamber and on the surface of the heat transfer element, and eventually lead to serious blockage of the flue gas channel, low-pressure secondary air channel, and high-pressure primary air channel, resulting in poor heat transfer. The efficiency is greatly reduced, so that it has to be cleaned and dredged, so that the equipment can work normally

In addition, the existing method of cleaning the dust accumulated on the inner wall of the chamber and the surface of the heat transfer element is to use pressure gas to blow soot, which has a poor cleaning effect, resulting in a decrease in the heat exchange efficiency of the equipment and a waste of energy

[0003] The lower temperature of the inner wall of the above-mentioned chamber usually occurs at the cold end of the rotor, because the air entering the rotor will efficiently cool the cold end of the rotor. When it does not rise, the condensation in the flue gas will accumulate on the inner wall of the chamber and the surface of the heat transfer element, resulting in serious blockage of the flue gas passage, low-pressure secondary air passage, and high-pressure primary air passage, and a significant reduction in heat transfer efficiency

[0004] In addition, most of the hot air that leaks between the hot-end fan-shaped plate between the flue gas and the secondary air and the end face of the rotor, and between the hot-end fan-shaped plate and the end face of the rotor between the flue gas and the primary air will flow into the negative pressure. The state of the flue gas channel and is discharged to the outside atmosphere, thus greatly increasing the heat loss of the boiler system

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