A method of increasing the flue gas temperature at the inlet of scr based on heat pipe

Abstract

The invention discloses a method for increasing a SCR inlet smoke temperature based on a heat pipe. The method comprises coal economizer furnace walls, heat pipe heat exchangers, a heat exchanger bracket, a heat pipe shell protection layer, a coal economizer, a low-temperature overheater, and an electric valve mounted on the protection layer and connected with a heat pipe shell. The method is characterized in that two rows of heat pipe heat exchangers are additionally mounted on the furnace walls on the left and right two sides of the coal economizer of a vertical shaft at the tail of a boiler; and a heat end of the heat pipe is positioned between the coal economizer and the low-temperature overheater, and a cold end is positioned behind the coal economizer. When the SCR inlet smoke temperature is too low, the electric valve is operated to extend the heat exchangers into the vertical shaft at the tail, and heat is continuously transferred from the front side of the coal economizer to smoke behind the coal economizer, so that the SCR inlet smoke temperature can be guaranteed in a reactor catalyst allowed range. The method adopts the heat pipe with efficient heat transfer and closed and compact structure to exchange heat of smoke in front of and behind the coal economizer, is simple in structure and easy to transform, and can effectively increase the SCR inlet smoke temperature.

Description

Technical field: [0001] The invention relates to a heat pipe-based method for increasing the flue temperature at an SCR inlet, and belongs to the technical field of transformation of boiler denitrification devices in power plants. Background technique: [0002] At present, power plants across the country are undergoing denitrification transformation. As the main method of denitrification, although SCR denitrification technology has matured, the control of inlet smoke temperature is still the main problem in this field. Low flue gas temperature at the inlet of the denitrification reactor will lead to a decrease in catalyst activity. If excessive ammonia gas is injected to control nitrogen oxides, the ammonia concentration in the tail flue will increase, ammonia escape will increase, and the concentration of sulfur trioxide will increase. raised. Ammonium bisulfate produced by ammonia and sulfur trioxide at a flue gas temperature of 200-300°C will stick to the denitrification...

AI Technical Summary

Problems solved by technology

Low flue gas temperature at the inlet of the denitrification reactor will lead to a decrease in catalyst activity. If excessive ammonia gas is injected to control nitrogen oxides, the ammonia concentration in the tail flue will increase, ammonia escape will increase, and the concentration of sulfur trioxide will increase. raised

The ammonium bisulfate produced by ammonia and sulfur trioxide at a flue gas temperature of 200-300°C will stick to the denitrification catalyst and air preheater, and absorb dust, causing the denitrification catalyst and air preheater to be blocked, and the denitrification reactor and air preheater to be blocked. The pressure difference of the air preheater increases slowly, which reduces the output of the induced draft fan and affects the output of the unit

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