CN215388159U - Power plant boiler SCR catalyst abrasionproof decreases protection device - Google Patents

Abstract

The utility model discloses a power station boiler SCR catalyst abrasion-proof protection device, which comprises a boiler tail flue, an air preheater inlet flue, a cyclone separator, a booster fan, a fan outlet regulating valve, an injector head and an ash bucket, wherein the boiler tail flue is connected with the air preheater inlet flue; the device comprises a boiler tail flue, an ammonia injection grid, an injection head and a denitration catalyst layer, wherein the boiler tail flue is internally provided with a coal economizer, the ammonia injection grid, the injection head and the denitration catalyst layer in sequence along the smoke circulation direction, an outlet of the boiler tail flue is communicated with an inlet flue of an air preheater, a smoke extraction air port is arranged on the boiler tail flue, the smoke extraction air port and the coal economizer are sequentially arranged along the smoke circulation direction, the smoke extraction air port is communicated with the injection head through a cyclone separator and a booster fan, and the device can effectively solve the problems that the concentration of fly ash particles on the front wall of the denitration flue is high and the catalyst is seriously worn and covered.

Description

Power plant boiler SCR catalyst abrasionproof decreases protection device

Technical Field

The utility model belongs to the technical field of boiler flue gas environmental protection of thermal power plants, and relates to an anti-abrasion protection device for an SCR catalyst of a power station boiler.

Background

The flue gas discharged by the boiler of the coal-fired power plant contains a large amount of nitrogen oxides, which cause serious pollution to the environment, so a flue gas purification device is required to be additionally arranged to remove the nitrogen oxides. The widely used flue gas denitration process at present mainly adopts a selective catalytic reduction method (SCR) and a non-selective catalytic reduction method (SNCR), which all utilize the activity of a catalyst to catalyze nitrogen oxides to be reduced into pollution-free nitrogen.

Referring to fig. 2, the catalyst is generally installed in the flue duct at the rear of the boiler in layers, and the flue gas carrying a large amount of fly ash particles needs to go through a turn from horizontal to forward to vertical to downward before entering the catalyst area, and the concentration of the ash particles at the front wall side is significantly higher than that at the rear wall side under the action of inertia force, gravity and the like. The unit is through the operation of year, and the denitration catalyst of front wall side receives more bigger wearing and tearing, the cladding effect, therefore takes place the broken perforation of catalyst module to form the flue gas corridor, both shortened denitrification facility life, weakened flue gas purification effect again.

At present, the guide plate is additionally arranged in the flue of the power plant, so that the problem of dust deposition on the side of the front wall is improved to a certain extent, the improvement amplitude is smaller, the effect is limited, and a more powerful and more direct problem solution must be explored.

How to solve the problems of large concentration of fly ash particles on the front wall of the denitration flue and serious abrasion and covering of the catalyst is a key for prolonging the service life of the denitration catalyst and improving the flue gas purification effect.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provides an anti-abrasion protection device for an SCR catalyst of a power station boiler, which can effectively solve the problems that the fly ash particle concentration of the front wall of a denitration flue is high and the abrasion and the coverage on the catalyst are serious.

In order to achieve the aim, the power station boiler SCR catalyst abrasion-proof protection device comprises a boiler tail flue, an air preheater inlet flue, a cyclone separator, a booster fan, a fan outlet adjusting door, an injector head and an ash bucket;

the boiler tail flue is internally provided with a coal economizer, an ammonia injection grid, an injection head and a denitration catalyst layer in sequence along the smoke circulation direction, the outlet of the boiler tail flue is communicated with the inlet flue of the air preheater, the boiler tail flue is provided with a smoke extraction port, wherein the smoke extraction port and the coal economizer are arranged in sequence along the smoke circulation direction, and the smoke extraction port is communicated with the injection head through a cyclone separator and a booster fan.

The smoke exhaust port is communicated with the injection head through a cyclone separator, a booster fan and a fan outlet regulating door.

An ash bucket is arranged at the bottom outlet of the boiler tail flue.

The ash bucket is opposite to the ammonia spraying grid.

The economizer is formed by winding a snakelike steel pipe.

The cyclone separator is a gas-solid separator.

The utility model has the following beneficial effects:

when the SCR catalyst abrasion-proof protection device of the power station boiler is specifically operated, high-temperature flue gas is extracted from the front side of the economizer, then the dust is removed through the cyclone separator, and then the high-temperature flue gas is blown to the rear wall from the front side through the booster fan and the injection head, so that the uniform distribution of fly ash particles on the whole catalyst layer is realized, the airflow disturbance at a denitration inlet is increased, the problems of high fly ash particle concentration at the front wall of a denitration flue and serious abrasion and coverage on the catalyst are effectively solved, and meanwhile, the flue gas temperature at the inlet of the denitration device under low load is reduced through extracting the high-temperature flue gas, so that the full-load denitration of the power station boiler is facilitated.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic structural diagram of the prior art.

Wherein, 1 is an economizer, 2 is a cyclone separator, 3 is a booster fan, 4 is a fan outlet regulating valve, 5 is an injection head, 6 is a denitration catalyst, 7 is an air preheater inlet flue, 8 is an ash bucket, and 9 is an ammonia injection grid.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

There is shown in the drawings a schematic block diagram of a disclosed embodiment in accordance with the utility model. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

Referring to fig. 1, the SCR catalyst anti-abrasion protection device for a utility boiler according to the present invention includes a boiler tail flue, an air preheater inlet flue 7, a cyclone separator 2, a booster fan 3, a fan outlet regulating gate 4, an injector head 5 and an ash bucket 8;

the coal economizer 1, the ammonia injection grid 9, the injector head 5 and the denitration catalyst layer 6 are sequentially arranged in the boiler tail flue along the smoke circulation direction, the outlet of the boiler tail flue is communicated with the inlet flue 7 of the air preheater, and the smoke extraction air port is arranged on the boiler tail flue, wherein the smoke extraction air port and the coal economizer 1 are sequentially arranged along the smoke circulation direction, and the smoke extraction air port is communicated with the injector head 5 through the cyclone separator 2, the booster fan 3 and the fan outlet adjusting door 4. The inlet of the ash bucket 8 is communicated with the bottom outlet of the boiler tail flue, and the ash bucket 8 is over against the ammonia injection grid 9.

The economizer 1 is formed by winding a snakelike steel pipe, the concentration of fly ash particles in the extracted flue gas is high, and solid fly ash particles are separated by the cyclone separator 2, so that the abrasion of blades in the booster fan 3 is reduced, and the nozzle of the injection head 5 is prevented from being blocked. The cyclone separator 2 is a gas-solid separator, and solid particles with larger inertial centrifugal force are thrown to the outer wall surface by utilizing the rotary motion caused by tangential introduction of airflow, so that gas-solid separation is realized. The cyclone separator 2 has the advantages of simple structure, large operation elasticity, high efficiency, convenient management and maintenance, low price and the like. The flue gas that booster fan 3 output spouts the front side in denitration flue through injector head 5, blows the front side flue gas that contains high concentration flying dust to the rear wall direction.

The working process of the utility model is as follows:

the extracted high-temperature flue gas is pressurized by a booster fan 3 after fly ash particles are removed by a cyclone separator 2, and then is sprayed into a catalyst front flue by a spray head 5. Because the whole flue is negative pressure and the flue gas output by the booster fan 3 is positive pressure, the airflow sprayed by the spraying head 5 has strong rigidity, and can disperse the flue gas with high fly ash content and promote the uniform distribution of fly ash particles. In addition, the pressure of the ejected high-temperature flue gas is adjusted through the fan outlet adjusting door 4, the flue gas flow rate is low under low load, the output of the booster fan 3 is small, the flue gas flow rate is high under high load, the flue gas quantity is large, the output of the booster fan 3 is required to be improved, and through reasonable adjustment, the device can obtain better airflow disturbance effect under different loads, so that the abrasion effect of high-concentration fly ash on the front-side catalyst is reduced, and the purpose of protecting the front-side catalyst is achieved.

In addition, the high-temperature flue gas extracted from the front of the economizer 1 is beneficial to improving the flue gas temperature at the inlet of the denitration device under the condition of low load of the boiler, thereby being beneficial to realizing full-load denitration.

Claims (6)

1. The utility boiler SCR catalyst abrasion-proof protection device is characterized by comprising a boiler tail flue, an air preheater inlet flue (7), a cyclone separator (2), a booster fan (3), a fan outlet adjusting door (4), an injector head (5) and an ash bucket (8);

economizer (1), ammonia injection grid (9), injector head (5) and denitration catalyst layer (6) have set gradually along flue gas circulation direction in the boiler afterbody flue, and the export of boiler afterbody flue is linked together with air preheater entry flue (7), is provided with the smoking gas mouth on the boiler afterbody flue, and wherein, smoking gas mouth and economizer (1) set gradually along flue gas circulation direction, and the smoking gas mouth is linked together with injector head (5) through cyclone (2) and booster fan (3).

2. The utility boiler SCR catalyst wear protection device of claim 1, wherein the fume extraction port is connected to the injector head (5) via a cyclone (2), a booster fan (3) and a fan outlet damper (4).

3. The utility boiler SCR catalyst wear protection device of claim 1, characterized in that an ash hopper (8) is provided at the bottom outlet of the boiler back pass.

4. The utility boiler SCR catalyst wear protection device of claim 1, characterized in that the ash hopper (8) is facing the ammonia injection grid (9).

5. The utility boiler SCR catalyst wear protection device of claim 1, characterized in that the economizer (1) is made by winding a serpentine steel tube.

6. The utility boiler SCR catalyst wear protection of claim 1, characterized in that the cyclone (2) is a gas-solid separator.

Images