CN208711444U

CN208711444U - A kind of SCR denitration is anti-blocking to propose effect system

Info

Publication number: CN208711444U
Application number: CN201821087264.5U
Authority: CN
Inventors: 官贞珍; 郭瑞堂; 潘卫国; 李芳芹
Original assignee: Shanghai University of Electric Power
Current assignee: Shanghai University of Electric Power; University of Shanghai for Science and Technology
Priority date: 2018-07-10
Filing date: 2018-07-10
Publication date: 2019-04-09
Anticipated expiration: 2028-07-10

Abstract

Effect system is proposed the utility model relates to a kind of SCR denitration is anti-blocking, including the gas approach set gradually by flow of flue gas direction, SCR denitration reaction device and exhaust pass, the gas approach is connect with economizer exit channel, the exhaust pass is connect with air preheater access road, the gas approach includes primary dedusting section and final dusting section, wherein, the entrance ash bucket for connecting the economizer exit channel is equipped in the primary dedusting section, the final dusting section is that bottom end connects the entrance ash bucket and along the acclivitous inclination flue in flow of flue gas direction, airflow-distribution board and ammonia-spraying grid are disposed with according to flow of flue gas direction in the inclination flue, outlet ash bucket is provided in the exhaust pass.Compared with prior art, the utility model reduces the stifled ash of SCR denitration system, and increases ammonia nitrogen mixability, significantly the high problem of the dust stratification of mitigation SCR denitration layer and air preheater pressure difference, guarantees the energy-efficient operation of SCR denitration system.

Description

A kind of SCR denitration is anti-blocking to propose effect system

Technical field

The utility model relates to a kind of SCR denitration systems, propose effect system more particularly, to a kind of SCR denitration is anti-blocking.

Background technique

Selective catalytic reduction (Selective Catalytic Reduction, SCR) is that coal-fired power station boiler is universal A kind of efficient NOx control technology used, and high dirt is mostly used to arrange greatly, i.e. SCR is located at economizer and air preheater (referred to as Air preheater) between.Due to being chronically at high dirt environment, catalyst easily blocks, wears and is poisoned.In addition, the dust in flue gas The easy spray ammonia mouth of blocking ammonia-spraying grid, so that the flow velocity inhomogeneities of ammonia rises, on catalyst inlet interface, ammonia nitrogen ratio is not yet Uniformity increases, to seriously affect the denitration effect of catalyst.NH₃- NOx mixes degree of irregularity often with runing time Passage it is further serious, partial region NH₃Concentration of escaping is much larger than 3ppm, and environmental protection index is not achieved in local NO x concentration of emission It is required that power plant often maintains low NOx emission concentration using ammonia spraying amount is increased, this undoubtedly increases ammonia consumption, while also leading Hydrogen sulfate ammonia (ABS) generation probability is caused to greatly increase.The ABS one side blocking catalyst duct of generation reduces catalyst activity； Another party's Surface ABS condenses into emplastic in the case where flue-gas temperature is lower than 230 DEG C, with flying dust mixed deposit in back-end ductwork Air preheater heat accumulating element on, reduce actual internal area in air preheater so that air preheater pressure difference increase, heat exchange efficiency reduce, The stability of unit operation reduces.

The method for reducing ammonia-spraying grid spray ammonia unevenness at present is that the spray ammonia of progress ammonia-spraying grid optimizes and revises test, that is, is adjusted Whole ammonia-spraying grid respectively sprays the ammonia spraying amount of ammonia branch pipe, so that NH in the flue gas of denitrating system entrance₃Concentration distribution and NOx concentration phase Match, utmostly improves uniformly distributed degree, reduce NH₃Concentration of escaping and NOx emission concentration.But it with the variation of boiler load and sets For the adjustment of operating status, the distribution of ammonia nitrogen ratio gradually becomes uneven cloth state, NH again at catalyst₃Escape amount increases again, NH can not fundamentally be solved₃Escape problem.

The dust stratification that SCR denitration system is cleaned in engineering will be needed to arrange more soot blowers, more frequently be blown Ash causes system to come into operation increased costs.

Utility model content

The purpose of this utility model is exactly to overcome the problems of the above-mentioned prior art and to provide a kind of SCR denitration anti- It is stifled to propose effect system.

The purpose of this utility model can be achieved through the following technical solutions:

A kind of SCR denitration is anti-blocking to propose effect system, including set gradually by flow of flue gas direction gas approach, SCR denitration Reactor and exhaust pass, the gas approach are connect with economizer exit channel, and the exhaust pass and air preheater entrance are logical Road connection, the gas approach includes primary dedusting section and final dusting section, wherein connection institute is equipped in the primary dedusting section The entrance ash bucket in economizer exit channel is stated, the final dusting section is that bottom end connects the entrance ash bucket and along flow of flue gas side To acclivitous inclination flue, airflow-distribution board and spray ammonia are disposed with according to flow of flue gas direction in the inclination flue Grid.

Further, the airflow-distribution board be disposed vertically in inclination flue in, the folder of airflow-distribution board and vertical direction Angle and inclination flue are identical as the angle of horizontal direction.

Further, the ammonia-spraying grid be disposed vertically in inclination flue in, it is parallel with airflow-distribution board.

Further, the ammonia-spraying grid is made of multiple groups for ammonia pipeline, described to be evenly arranged in inclination cigarette for ammonia pipeline On the section in road.

Further, described for being evenly arranged multiple nozzles on ammonia pipeline.

Further, the spray angle of the nozzle and the angle in flow of flue gas direction are not more than 90 degree.It is furthermore preferred that spray In mouth there are two spray angle also in non-vertical position, and then it is possible to prevente effectively from secondary landing dust plug nozzle.

Further, the SCR denitration reaction device is provided with SCR denitration layer, on the SCR denitration layer Side, which is equipped with, makes ammonia nitrogen than being distributed uniform flow straightening grid.

Further, outlet ash bucket is provided in the exhaust pass.

The flue gas for carrying a large amount of soot particles enters entrance ash bucket from economizer exhaust pass and realizes an ash disposal, inclines into denitration In oblique flue, after encountering airflow-distribution board, since the quality and inertia of soot particle are larger, change it after striking airflow-distribution board The direction of motion falls on it obliquely in entrance ash bucket and realizes secondary ash disposal, and a large amount of ash is prevented to enter SCR reactor, More clean flue gas flow velocity after airflow-distribution board becomes uniformly, to continue up flowing by ammonia-spraying grid, ammonia-spraying grid by In slant setting, substantially reduces a small amount of flying dust carried in flue gas and fall into a possibility that nozzle results in blockage, and multi-angle nozzle Make NH₃It is sprayed from three kinds of angles, area coverage is big, improves NH₃The uniformity mixed with NOx in flue gas.NH₃It is very low with dust-laden Flue gas mixing after eliminated after guide vane and flow straightening grid at variable diameter formed flow field problem of non-uniform so that into First floor catalyst ammonia nitrogen score cloth becomes uniformly, to can get comparatively ideal denitration effect, and control NH₃Escape.By denitration Denitration flue gas after catalyst layer enters in air preheater after realizing ash disposal three times using outlet ash bucket.

Compared with prior art, the utility model has the following beneficial effects:

1, flue gas is in entrance ash bucket after primary dedusting, and into when tilting flue, ash particle will overcome the effect of gravity Reduce the soot particle for reaching inclination flue；

2, the setting of airflow-distribution board may be implemented final dusting and flow；

3, tilted-putted ammonia-spraying grid reduces the stifled ash of nozzle, and increases ammonia nitrogen mixability, significantly mitigation SCR The dust stratification problem of denitration catalyst oxidant layer guarantees the energy-efficient operation of SCR denitration system；

4, multi-angle nozzle makes NH₃It is sprayed from multiple angles, area coverage is big, improves NH₃It is mixed with NOx in flue gas Uniformity.

Detailed description of the invention

Fig. 1 is a kind of anti-blocking schematic diagram for proposing effect system of SCR denitration of the utility model；

Fig. 2 is the schematic diagram of conventional scr denitrating system；

Fig. 3 is the nozzle schematic diagram of the ammonia-spraying grid in the utility model；

Fig. 4 is the nozzle schematic diagram of conventional ammonia-spraying grid.

Shown in figure label:

1, entrance ash bucket, 2, inclination flue, 3, airflow-distribution board, 4, ammonia-spraying grid, 5, guide vane, 6, flow straightening grid, 7, SCR denitration layer, 8, outlet ash bucket, 9, nozzle, 10, for ammonia pipeline, 11, air preheater, 12, economizer.

Specific embodiment

The utility model is described in detail in the following with reference to the drawings and specific embodiments.

Embodiment

Existing SCR denitration system as shown in Fig. 2, ammonia-spraying grid 4 is arranged horizontally in conventional scr denitrating system, due to Flue arranges that the spray of ammonia-spraying grid 4 ammonia direction is identical as flow of flue gas direction vertically, and with reference to Fig. 4, general nozzle uses single spraying Mouth, and arrange vertically upward, a large amount of flying dusts carried in flue gas are since gravity can fall into nozzle, to block jet pipe, sternly The uniformity coefficient of ammonia nitrogen is affected again.The flue gas stream for separately carrying a large amount of flying dusts passes through SCR denitration layer 7 from top to bottom When, flying dust promote under the effect of gravity SCR denitration layer 7 into ash and dust stratification.

The present embodiment proposes that a kind of SCR denitration is anti-blocking to propose effect system, enters including what is set gradually by flow of flue gas direction Mouth flue, SCR denitration reaction device and exhaust pass, gas approach are connect with economizer 12, and exhaust pass is connect with air preheater 11, Gas approach includes primary dedusting section and final dusting section, wherein connection 12 exit passageway of economizer is equipped in primary dedusting section Entrance ash bucket 1, final dusting section is that bottom end connects entrance ash bucket 1 and along the acclivitous inclination flue 2 in flow of flue gas direction, Airflow-distribution board 3 and ammonia-spraying grid 4 are disposed with according to flow of flue gas direction in inclination flue 2.Airflow-distribution board 3 is vertically put It is placed in inclination flue 2.Ammonia-spraying grid 4 be disposed vertically in inclination flue 2 in, it is parallel with airflow-distribution board 3.Ammonia-spraying grid 4 by Multiple groups are formed for ammonia pipeline 10, are evenly arranged on the section of inclination flue 2 for ammonia pipeline 10, for being evenly arranged on ammonia pipeline 10 There are multiple nozzles 9, spray angle and the angle in flow of flue gas direction are not more than 90 degree.SCR denitration reaction device is provided with SCR denitration Catalyst layer 7, being equipped with above SCR denitration layer 7 makes ammonia nitrogen flow straightening grid 6 more uniform than distribution.Setting in exhaust pass There is outlet ash bucket 8.

It is once removed as shown in Figure 1, carrying the flue gases of a large amount of soot particles and from 12 exhaust pass of economizer entering entrance ash bucket 1 and realize Ash after encountering airflow-distribution board 3, since the quality and inertia of soot particle are larger, is striking gas into denitration inclination flue 2 Change its direction of motion after flow point fabric swatch 3, fall on it obliquely in entrance ash bucket 1 and realize secondary ash disposal, prevents a large amount of Ash enter SCR reactor, more clean flue gas flow velocity after airflow-distribution board 3 becomes uniformly, to continue up flowing and pass through Ammonia-spraying grid 4, ammonia-spraying grid 4 are substantially reduced a small amount of flying dust carried in flue gas and fall into nozzle 9 and resulted in blockage due to slant setting A possibility that, as shown in figure 3, multi-angle nozzle 9 makes NH₃It is sprayed from three kinds of angles, area coverage is big, improves NH₃In flue gas The uniformity of NOx mixing.NH₃Variable diameter is eliminated after guide vane 5 and flow straightening grid 6 after the flue gas mixing very low with dust-laden Locate the flow field problem of non-uniform formed, so that becoming uniformly, to can get comparatively ideal de- into first floor catalyst ammonia nitrogen score cloth Nitre effect, and control NH₃Escape.Denitration flue gas after SCR denitration layer 7 realizes three using outlet ash bucket 8 Enter in air preheater 11 after secondary ash disposal.

It can understand the above description of the embodiments is intended to facilitate those skilled in the art and use practical It is novel.Person skilled in the art obviously easily can make various modifications to these embodiments, and illustrating herein General Principle be applied in other embodiments without having to go through creative labor.Therefore, the utility model is not limited to above-mentioned Embodiment, those skilled in the art's announcement according to the present utility model, do not depart from improvement that the utility model scope is made and Modification should be all within the protection scope of the utility model.

Claims

It is anti-including the gas approach that is set gradually by flow of flue gas direction, SCR denitration 1. a kind of SCR denitration is anti-blocking to propose effect system Device and exhaust pass are answered, the arrival end of the gas approach is also connect with economizer (12) exit passageway, the exhaust pass Outlet end is also connect with air preheater (11) access road, which is characterized in that the gas approach includes sequentially connected once removing Dirt section and final dusting section, wherein the entrance ash for connecting economizer (12) exit passageway is equipped in the primary dedusting section It struggles against (1), the final dusting section is that bottom end connects the entrance ash bucket (1) and along the acclivitous inclination cigarette in flow of flue gas direction Road (2), the inclination flue (2) is interior to be disposed with airflow-distribution board (3) and ammonia-spraying grid (4) according to flow of flue gas direction.
2. a kind of SCR denitration according to claim 1 is anti-blocking to propose effect system, which is characterized in that the airflow-distribution board (3) It is disposed vertically in inclination flue (2).
3. a kind of SCR denitration according to claim 1 is anti-blocking to propose effect system, which is characterized in that the ammonia-spraying grid (4) is hung down It is directly placed in inclination flue (2), it is parallel with airflow-distribution board (3).
4. a kind of SCR denitration according to claim 1 is anti-blocking to propose effect system, which is characterized in that the ammonia-spraying grid (4) by Multiple groups are formed for ammonia pipeline (10), on the section that inclination flue (2) is evenly arranged in for ammonia pipeline (10).
5. a kind of SCR denitration according to claim 4 is anti-blocking to propose effect system, which is characterized in that described for ammonia pipeline (10) On be evenly arranged multiple nozzles (9).
6. a kind of SCR denitration according to claim 5 is anti-blocking to propose effect system, which is characterized in that the injection of the nozzle (9) The angle in angle and flow of flue gas direction is not more than 90 degree.
7. a kind of SCR denitration according to claim 1 is anti-blocking to propose effect system, which is characterized in that the SCR denitration reaction device It is provided with SCR denitration layer (7), being equipped with above the SCR denitration layer (7) makes ammonia nitrogen than being distributed uniform rectification Grid (6).
8. a kind of SCR denitration according to claim 1 is anti-blocking to propose effect system, which is characterized in that set in the exhaust pass It is equipped with outlet ash bucket (8).