A method for optimizing the molar ratio distribution of ammonia nitrogen in scr denitrification system

Abstract

The invention discloses a method for optimizing ammonia nitrogen mole ratio distribution of an SCR denitration system. The method comprises the following implementation steps: detecting to obtain NOX concentration distribution within each control period at the inlet of the SCR denitration system and NOX concentration distribution and NH3 concentration distribution within each control period at the outlet; within each control period, calculating an ammonia nitrogen mole ratio distribution relative standard deviation factor CVm of the SCR denitration system within the current control period, and while the ammonia nitrogen mole ratio distribution relative standard deviation factor CVm exceeds a preset threshold value, automatically optimizing in allusion to an ammonia spraying control valve of the SCR denitration system, ending and quitting the automatic optimization while the ammonia nitrogen mole ratio distribution relative standard deviation factor CVm does not exceed the preset threshold value. The method is capable of effectively regulating the ammonia nitrogen mole ratio distribution of the SCR denitration system, solving the problems that the outlet ammonia escape rate of the SCR denitration system is high, the outlet NOX concentration distribution is not uniform and the produced ammonium bisulfate blocks an air pre-heater, remarkably improving the flow field distribution in an SCR reactor, and effectively improving the availability ratio of the SCR denitration system.

Description

technical field [0001] The invention relates to the SCR denitrification technology of a coal-fired power plant, in particular to a method for optimizing the distribution of the ammonia nitrogen molar ratio in the SCR denitrification system. Background technique [0002] In selective catalytic reduction (SCR) systems, denitrification efficiency and outlet ammonia slip are the main performance characterization parameters. Due to the limited reserved space, the uneven distribution of the flue gas flow field generally exists in the denitrification upgrading of existing coal-fired power plants. There is a certain deviation in the NOX concentration, which is not conducive to the fine-tuning operation of the operator; at the same time, it also leads to high ammonia escape at the SCR outlet, and the generated ammonium bisulfate is likely to reduce the normal operation cycle of the air preheater. Therefore, how to realize a method to optimize the molar ratio distribution of ammonia ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved in the present invention: Aiming at the above-mentioned problems of the prior art, provide a method that can effectively adjust the ammonia nitrogen molar ratio distribution of the SCR denitrification system, and solve the problem of high ammonia escape at the outlet of the SCR denitrification system and NO at the outlet. X The method of optimizing the molar ratio distribution of ammonia nitrogen in the SCR denitrification system can effectively improve the distribution of the flow field in the SCR reactor and effectively improve the availability of the SCR denitrification system. The ammonia nitrogen molar ratio distribution on the upper layer of the catalyst improves the overall performance of the system, effectively reduces ammonia slip and ensures the efficient and stable operation of the air preheater while ensuring that NOX emissions meet the standards

Images