Controllable scouring system for cleaning heating surfaces of boiler and method

Abstract

The invention discloses a controllable scouring system for cleaning heating surfaces of a boiler and a method, particularly a method used for feeding a soot blowing medium (sand grains carried by flowing gas) into a hearth through sandblast openings in different positions to scour and clean the heating surfaces of the boiler. The method is characterized in that a plurality of sets of the sandblast openings are formed in the positions, behind a main combustion area and in front of the heating surfaces which have high probabilities of slag bonding and contamination, on the wall of the boiler, the sandblast openings are kept away from the high-temperature combustion area, the soot blowing medium with controllable flow rate and sand grain content is sprayed into the hearth, the sand grains are not fused and flow in the whole hearth to scour slag and soot on the heating surfaces of the boiler at a certain speed and angle. By virtue of the scouring and abrading functions of the sand grains on slag and soot on the heating surfaces of the boiler, slag and soot on the heating surfaces are abraded, crushed and separated, and the sand grains with favorable liquidity flow through all the heating surfaces along with flue gas, so that all the heating surfaces can be immediately and effectively scoured and cleaned without dead angles.

Description

technical field [0001] The invention relates to the technical field of cleaning the heating surface of a boiler, in particular to a system and method for cleaning the heating surface of a boiler by using flowing gas to send sand particles into a furnace to controllably erode the heating surface. Background technique [0002] my country's thermal power generation is dominated by coal. During the operation of coal-fired boilers, when the flue gas with a temperature higher than the ash melting point scours the heating surface, the molten ash in the flue gas will adhere to the heating surface to form slagging; when the flue gas When the gas temperature is lower than the ash melting point, the fly ash deposits on the heating surface of the boiler and easily forms ash deposits. Therefore, slagging and ash accumulation on the heating surface of boilers is a common problem in the operation of coal-fired boilers, especially when using coal with high alkali metal content (such as Zhund...

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Problems solved by technology

Due to the limited direction and area of ​​mechanical rapping, there is a dead angle for cleaning dust; steam soot blowing uses continuous high-pressure steam to blow the tube wall of the heating surface, which not only causes serious wear of mechanical parts but also consumes a lot of energy; The energy intensity of soot blowing is insufficient, and the ability to clean ash deposits is limited; gas pulse soot blowing uses combustible gas deflagration to generate shock waves to clean the heating surface, which can only be used in low temperature sections, and its application range is limited; water gun slag washing technology also needs to consider slag washing water recycling and discharge

At the same time, the soot blowing system of power plant boilers usually sets the soot blowing cycle first, and periodically cleans the soot according to the expected time. Insufficient ash or too frequent ash blowing affects the heat transfer efficiency of the heating surface of the boiler

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