Device and method for relieving blockage of rotary air pre-heater by means of hot primary air preheating and heat storage elements

Abstract

The invention discloses a device and method for relieving blockage of a rotary air pre-heater by means of hot primary air preheating and heat storage elements. The device structurally comprises a hotprimary air guiding-out pipeline, an adjusting air door, a turning-off air door, a preheating bin hot-end sector plate, a preheating bin cold-end sector plate, a preheating cold air guiding-out pipeline and the like. An independent heat storage element preheating bin is formed between the preheating bin hot-end sector plate and the preheating bin cold-end sector plate and is located in front of anair distribution bin before the rotary air pre-heater is turned to a flue gas branch bin and the flue gas branch bin, the heat storage element is preheated from top to bottom by the aid of hot primary air, and the temperature of the heat storage element entering the flue gas branch bin is increased, so that the purpose of reducing the ammonium bisulfate (ABS) deposition area is achieved, the ABSdeposition area can be cleared by the aid of a soot blower more easily, and the problem that the air pre-heater is blocked seriously due to the fact that ABS adheres to the rotary air pre-heater of aboiler of a coal-fired power plant is solved.

Description

technical field [0001] The invention relates to a device and method for alleviating clogging of a rotary air preheater, belonging to the field of clogging prevention and control of a rotary air preheater. Background technique [0002] Selective catalytic reduction technology (SCR for short) is a denitrification technology widely used in thermal power units at present. Its technical principle is to inject ammonia (NH 3 ), under the action of catalyst and in the presence of oxygen, NH 3 Prioritize the reduction and removal reaction with nitrogen oxides (NOx) in the flue gas to generate nitrogen and water. In addition to the above main reaction, it will also be accompanied by a small amount of sulfur dioxide (SO 2 ) oxidized to sulfur trioxide (SO 3 ), and then generate ammonium bisulfate (NH 4 HSO 4 , also known as ABS). ABS has strong viscosity in liquid state, and ABS will condense in the temperature window of 146 ℃ ~ 220 ℃ in the flue gas. [0003] Rotary air preheate...

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Problems solved by technology

[0003] Rotary air preheater (referred to as "rotary air preheater" or "air preheater") is an important heat exchange equipment for coal-fired units. , to heat the low-temperature air entering the furnace, the temperature range of the flue gas flowing through the rotary air preheater is 110°C~400°C, and the metal wall temperature of the heat exchange element is generally 80°C~380°C, which exceeds the ABS condensation Therefore, when there is ABS in the flue gas, ABS is easy to condense and deposit on the surface of the heat storage element of the air preheater, and the strong viscosity is also very easy to adhere to the fly ash in the flue gas, thus causing the air preheater to enter The outlet pressure difference gradually increases, and the blockage gradually increases

[0004] At the same time, in recent years, due to the implementation of ultra-clean emission transformation projects and the reduction of unit load rate, the problems of ABS clogging and corrosion of air preheaters in coal-fired thermal power plants have become more prominent. As high as 3000~4000Pa, the light will increase the power consumption of the fan and the economy will decline, and the severe one will affect the load capacity of the unit, and even the accident of the fan stalling and shutting down will seriously affect the normal operation of the unit

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