An evaluation method for the effect of the flow field modification of the secondary wind box of the opposing coal-fired boiler

Abstract

The invention relates to a method for evaluating the effect of the secondary wind box flow field modification of a counter-coal-fired boiler: it includes: in a hot state, testing the relative standard deviation of the cross-sectional velocity field distribution at the pre-installed measuring hole section before and after the modification; The temperature of the tube wall on the heating surface, and form a comparative distribution map; test the flue gas composition at the outlet section of the economizer before and after the transformation, and form a comparative distribution map; test the reducing atmosphere of the water-cooled wall in the furnace before and after the transformation. The present invention uses the distribution curve of the tube wall temperature to judge the uniformity of the tube wall temperature; checks the thickness of the tube wall when the furnace is stopped and the reducing atmosphere of the water wall in the furnace under the hot state to judge the degree of corrosion; uses the relative standard of temperature and speed distribution The deviation is used to judge the uniformity of the flow field, which provides a reference for the evaluation method of the secondary wind box flow field modification of the same type of unit, and enriches the original evaluation method.

Description

technical field [0001] The invention relates to the field of boiler transformation, in particular to an effect evaluation method after transformation of the flow field of the secondary wind box of the opposing coal-fired boiler. Background technique [0002] With the gradual increase of the parameters of the unit, especially the unit where the temperature of the hot reheat steam is increased to 620°C, the problems of tube wall overtemperature tube explosion and high temperature corrosion in the furnace are particularly prominent under various loads, which have also attracted widespread attention. The research on the material analysis of the tube explosion on the heating surface shows that in addition to the properties of the tube itself and the welding process, the overheating of the tube wall is also an important cause of the tube explosion. Therefore, it is particularly important to strengthen the monitoring of tube wall temperature. Several major boiler factories have ado...

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Problems solved by technology

However, since the combustion process in the furnace is a dynamic process, it is greatly affected by the type of coal, the contamination in the furnace, etc., and the stability of the combustion optimization effect is not enough.

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