Method for mixedly burning brown coal by using drying margin of mid-speed grinding mill

Abstract

The invention discloses a method for mixedly burning brown coal by using drying margin of a mid-speed grinding mill. By mixedly burning the brown coal, the exit temperature of the mid-speed grinding mill is reduced to 60-65 DEG C; and by closing a cold air door of the mid-speed grinding mill and fully opening a hot air door of the mid-speed grinding mill, the inlet temperature of the mid-speed grinding mill is improved to the maximum value of the mid-speed grinding mill, so the drying output of the mid-speed grinding mill can be fully utilized, and a consequence that the mid-speed grinding mill explodes in the process of mixedly burning the brown coal is avoided; meanwhile, on the premise of ensuring the safe running state of the mid-speed grinding mill, the brown coal is mixedly burnt in the maximum proportion, so the brown coal is fully utilized, and the safety of the mid-speed grinding mill, the load-bearing capacity of a generator set and the economy of the generator set are not reduced.

Description

Technical field [0001] The invention relates to a method for increasing the ratio of lignite blending, in particular to a method for blending lignite with a medium-speed grinding drying margin. Background technique [0002] At present, due to the shortage of bituminous coal sources, domestic power plants generally need to blend lignite coal with a large difference in quality from bituminous coal. Due to the high moisture content of lignite, power plants usually consider increasing the inlet temperature and The method of reducing the outlet temperature of the medium-speed mill to create a temperature difference between the inlet of the medium-speed mill and the outlet of the medium-speed mill. This temperature difference produces a drying margin for the lignite, so as to increase the drying output of the medium-speed mill to dry the lignite. The purpose of moisture. However, when mixed firing in various power plants, the outlet temperature of the medium-speed mill is often adjust...

AI Technical Summary

Problems solved by technology

However, when the power plants are blending combustion, the outlet temperature of the medium-speed mill is often adjusted too low or too high. If the outlet temperature of the medium-speed mill is too low, the combustion utilization rate of the pulverized coal sent to the boiler from the medium-speed mill will be reduced. As a result, the load capacity of the generating set and the economic efficiency of the generating set are reduced; while the outlet temperature of the medium-speed mill is too high, because the lignite is also prone to spontaneous combustion and explosion, it is easy to cause explosion and burnout of the burner; this also It directly led to the reduction of lignite blending ratio in power plants to avoid the occurrence of these defects, resulting in low utilization rate of lignite

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