Optimal control system and method for combustion of high-alkali coal of wet bottom boiler

Abstract

The invention belongs to the technical field of coal-fired power generation, and discloses an optimal control system and method for combustion of high-alkali coal of a wet bottom boiler. The system comprises a DCS control system, a monitoring system and a flue gas and air combustion system, wherein the monitoring system and the flue gas and air combustion system are connected with a combustion chamber of the wet bottom boiler; the monitoring system comprises a first alkali metal concentration detector and a plurality of second alkali metal concentration detectors; the first alkali metal concentration detector is arranged on a radiation chamber of the wet bottom boiler; the second alkali metal concentration detectors are arranged on the combustion chamber along the flame stroke; the first alkali metal concentration detector and the plurality of second alkali metal concentration detectors are connected with the DCS control system; and a high-alkali coal burner, a burner hot air regulating valve, a grading air regulating valve and a deep grading air regulating valve of the flue gas and air combustion system are all connected with the DCS control system. When high-alkali coal is combusted traditionally, time delay is large, regulation and control work lag is serious, as a result, safe and continuous combustion of the high-alkali coal is not facilitated. With the optimal control system and method for the combustion of the high-alkali coal for the wet bottom boiler of the invention adopted, the above problem can be solved, and slag blockage of the boiler and serious coking and contamination of a heating surface are prevented.

Description

technical field [0001] The invention belongs to the technical field of coal-fired power generation, and relates to an optimization control system and method for burning high-alkali coal in a liquid slag discharge boiler. Background technique [0002] The alkali metal content in high-alkali coal is as high as 4%, and direct combustion may cause a large amount of coking in the furnace, contamination of heating surfaces and tail flue equipment, and other serious problems that endanger the safety of boiler operation. Conventional pulverized coal solid-state slagging boilers are difficult to achieve the goal of purely burning high-alkali coal. Liquid slagging boilers have the advantage of liquid slagging, which can capture a large amount of alkali metals in the liquid slag in the furnace, making the flue gas The concentration of medium and alkali metals is controlled within the range allowed by the safe operation of boiler-related equipment. [0003] The current combustion and m...

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Problems solved by technology

[0005] The purpose of the present invention is to overcome the above-mentioned prior art. The boilers burning high-alkali coal mainly rely on the slagging and ash blocking of high-alkali coal on site to optimize and adjust the combustion of high-alkali coal. There is a long delay and serious control work. Defects such as hysteresis are not conducive to the safe and continuous combustion of high-alkali coal, and an optimal control system and method for burning high-alkali coal in liquid slagging boilers are provided

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