CN214307166U

CN214307166U - Industrial boiler capable of effectively denitrating in boiler

Info

Publication number: CN214307166U
Application number: CN202120197283.9U
Authority: CN
Inventors: 李俊东; 曾国辉; 王林海; 朱先明; 李维伟
Original assignee: Tianjin Hechuang Boiler Technology Co ltd
Current assignee: Tianjin Hechuang Boiler Technology Co ltd
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-09-28
Anticipated expiration: 2031-01-25

Abstract

The utility model relates to an industrial boiler that can effectively denitrate in stove, including boiler body, combustion apparatus, the flue gas loops through preceding furnace, back furnace, furnace export entering water-cooling flue, gets into low temperature convection heating surface back discharge boiler body from connecting tube behind the high temperature convection heating surface that sets up in the water-cooling flue again. The utility model discloses roll over the cigarette wall before with, roll over the cigarette wall after, preceding top wall, the passageway that forms between the back top wall designs contrary "S" shape flue gas flow, furnace after with, the lower part passageway of water-cooling flue designs anti- "J" shape flue gas flow, it is little to have solved the furnace space that is fit for SNCR denitration smoke temperature requirement at present, the flue gas stroke is short, the flue gas mixes the effect with the denitrifier poor, the problem that SNCR denitration efficiency is low, make the inside furnace space that has increased and is fit for SNCR denitration flue gas temperature requirement of furnace, the flue gas flow has been increased, strengthened flue gas and denitrifier vertically and width direction' S mixture at furnace, SNCR denitration reaction efficiency has greatly been improved.

Description

Industrial boiler capable of effectively denitrating in boiler

Technical Field

The utility model belongs to industrial boiler and environmental protection field relate to denitration in industrial boiler and the industrial boiler flue gas stove, especially an industrial boiler that can effectively denitration in the stove.

Background

The existing industrial boiler is mature in the aspects of fuel ignition, combustion, burnout, full heat exchange between flue gas and working media and the like, and is reasonable in structure, safe and reliable. With the increasing of the requirement of environmental protection in recent years, the SNCR, SCR and SNCR + SCR denitration technologies become the main means for flue gas denitration treatment of industrial boilers, but when the existing industrial boilers are used in combination with the denitration technologies, some disadvantages exist, and are specifically embodied as follows:

1. the furnace space that current industrial boiler is fit for SNCR denitration gas temperature requirement is little, the flue gas stroke is short, and the furnace structure is poor to flue gas and denitrifier extension furnace fore-and-aft flue gas mixing effect, lacks the mixing ability at furnace width direction simultaneously, and denitration efficiency is on the low side, only about 30%.

2. When the SCR denitration is used in the existing industrial boiler, the change range of the operation load of the boiler is only about 30% in order to meet the requirement of the boiler on the smoke temperature, so that the SCR denitration cannot be put into operation when the boiler is in low-load operation. If the change range of the operation load of the boiler is enlarged, a means for adjusting the temperature of the smoke in the boiler is not provided, the effect of adjusting the temperature of the smoke can be achieved only by a mode of mixing the high-temperature smoke and the low-temperature smoke outside the boiler, but the mode of adjusting the temperature of the smoke outside the boiler has the defects of large occupied space of a high-temperature and low-temperature flue, large heat dissipation loss, large air leakage and the like.

Through a search of patent documents, the applicant has found the following two publications relating to the present patent application:

1. a high-efficiency semi-coke industrial boiler (CN106907850A) with denitration relates to the field of combustion. The utility model discloses a supply air plenum, with the communicating high temperature seal combustion chamber of supply air plenum, cut apart and the slope sets up the fixed grate of big inclination on supply air plenum upper portion with the seal combustion chamber of high temperature with the supply air plenum, communicate with the seal combustion chamber of high temperature and set up in the feed passageway of the fixed grate eminence one end of big inclination, the hopper of being connected with feed passageway, the stove arch on high temperature seal combustion chamber upper portion is located in the slope, set up in a plurality of high temperature exhanst gas outlets of stove arch front end, the equal mixing chamber of high temperature with high temperature exhanst gas outlet intercommunication respectively, the high temperature flue gas heat transfer export that links to each other with the equal mixing chamber of high temperature, just insert the denitration shower nozzle's of denitration shower nozzle to the equal mixing chamber of high temperature entry, the indirect heating equipment of high temperature flue gas heat transfer export intercommunication is passed through with the equal mixing chamber of high temperature.

2. An industrial boiler SNCR intelligent deNOx systems (CN111375298A), includes: the stirring barrel is used for mixing the high-efficiency denitration powder and water to form a directly usable high-efficiency denitration medicinal liquid; the medicine storage barrel is communicated with the water outlet end of the stirring barrel and is used for storing the denitration medicine water agent; the circulating conveying module is communicated with the medicine storage barrel, a high-pressure water pump is used for conveying the denitration medicine liquid, and part of the denitration medicine liquid circulates in the communicated pipeline; the control conveying module is used for controlling and adjusting the usage amount of the medicinal liquid; the compressed air injector is communicated with the control conveying module and is sprayed into the hearth after atomization.

Through the contrast of technical characteristics, above-mentioned two open patent documents, its technical structure with the utility model discloses the application has great difference, can not influence the utility model discloses the creativity of application.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome prior art's weak point, provide an industrial boiler that can effectively denitrate in the stove, this boiler has effectively solved following problem: the hearth space that is fit for SNCR denitration smoke temperature requirement is little, the flue gas stroke is short and flue gas and denitrifier mix the effect poor, SNCR denitration inefficiency to and can't realize through the interior smoke temperature regulation of stove, make the SCR denitration can put into use in the problem of bigger boiler load variation within range.

The utility model discloses the technical scheme who realizes the purpose is:

the utility model provides an industrial boiler that can effectively denitrate in stove, including the boiler body, combustion apparatus, this internal furnace that is provided with of boiler, combustion apparatus arranges the lower part of this internal furnace of boiler in, this internal furnace of boiler is the diaphragm type wall structure, by the side wall formation of front wall, back wall and both sides and adopt intermediate wall to make it constitute preceding furnace and back furnace, the flue gas loops through preceding furnace, back furnace, the furnace export gets into the water-cooling flue, get into low temperature convection heating surface from the connecting tube behind the high temperature convection heating surface that sets up in the water-cooling flue again, then discharge the boiler body, its characterized in that: the middle part of the front wall forming the front hearth protrudes backwards to form a front smoke folding wall of the hearth, and the upper part of the front wall is bent backwards to form a front top wall of the hearth; the upper part of the middle partition wall is bent forwards to form a rear smoke folding wall of the hearth, and the rear smoke folding wall is upwards divided into a plurality of sections and pulled into two rows of mixed smoke walls; the upper part of the rear wall is bent forwards to form a hearth rear top wall, the lower part of the rear wall is a hearth outlet, flue gas reversely bends 180 degrees from the hearth outlet and enters the water-cooling flue, so that the front smoke-bending wall, the rear smoke-bending wall, the front top wall and the rear top wall of the hearth form an inverse S-shaped flue gas flow, and the rear hearth and the lower part of the water-cooling flue form an inverse J-shaped flue gas flow.

And a row of denitrifier nozzles are respectively designed on the two sides of the front hearth and/or the front wall, the height position of the front smoke-folding wall and the upper and lower hearths thereof, three rows of denitrifier nozzles are matched for use, the lower and middle rows of denitrifier nozzles are used when the boiler operates at low load, and the upper and lower rows of denitrifier nozzles are used when the boiler operates at medium and high load.

And the rear smoke folding wall of the hearth is upwards divided into a plurality of sections which are drawn into two rows to form a mixed smoke wall, the width of each section is more than 500mm, and the front and rear rows are arranged in a staggered manner.

And a fireproof heat-insulating layer is designed on the surface of the membrane wall above the front smoke-folding wall of the hearth.

And the water-cooling flue behind the rear wall of the hearth is of a membrane wall structure and consists of the rear wall of the hearth, the rear wall of the water-cooling flue and a side wall, the upper part of the rear wall of the hearth, which extends the whole width of the hearth, is provided with a flue gas short-circuit port, and a flue gas temperature regulating door is arranged.

Moreover, the flue gas short circuit port is arranged along the width of the whole water-cooling flue, or is uniformly divided into a plurality of sets along the width of the whole flue; the water-cooled wall of the flue gas short circuit port part is a light tube water-cooled wall, and a gap between every two light tubes forms a flue gas short circuit port; the smoke temperature adjusting door is made of heat-resistant materials, and the opening degree of the smoke temperature adjusting door can be adjusted.

And the high-temperature convection heating surface arranged in the water-cooling flue is a flag type heating surface, a coiled pipe heating surface or other convection heating surfaces, and the outlet smoke temperature of the high-temperature convection heating surface is designed to be slightly lower than the upper limit temperature suitable for the SCR denitration reaction temperature.

And when the flue gas needs lower NOx emission, an SCR denitration reactor is arranged between the water-cooling flue and the low-temperature convection heating surface, and a catalyst is arranged, so that the flue gas enters the low-temperature convection heating surface after being denitrated by the SCR denitration reactor.

The utility model has the advantages that:

1. the utility model discloses roll over the cigarette wall before with, roll over the cigarette wall after, preceding top wall, the passageway that forms between the back top wall designs contrary "S" shape flue gas flow, furnace after will, the lower part passageway of water-cooling flue designs anti- "J" shape flue gas flow, it is little to have solved the furnace space that is fit for SNCR denitration smoke temperature requirement, the flue gas stroke is short, flue gas and denitrifier mix the effect poor, the problem of SNCR denitration inefficiency, make the inside furnace space that has increased and be fit for SNCR denitration flue gas temperature requirement of furnace, increase flue gas flow, strengthen flue gas and denitrifier vertically and width direction' S mixture at furnace, through calculating, can improve SNCR denitration reaction efficiency to about 60%, the effect is very obvious.

2. The utility model discloses design into a flue gas short circuit mouth with furnace back wall upper portion along whole furnace width, be equipped with a flue gas temperature regulating gate at this flue gas short circuit mouth, high temperature flue gas on back furnace upper portion can short circuit to the low temperature flue gas on water-cooling flue upper portion in an appropriate amount under the control of this flue gas temperature regulating gate, can be in 60% boiler load variation within range, make water-cooling flue outlet flue gas temperature keep in the temperature range that is fit for SCR denitration needs, the problem of can't realize through the regulation of furnace flue gas temperature and make SCR denitration can come into use in bigger boiler load variation range is solved, the regulation to flue gas temperature inside the boiler has been realized, the required suitable flue gas temperature of making boiler SCR denitration can be realized through high low temperature flue gas mixing in the stove, the load variation range when making SCR use on industrial boiler increases at double; meanwhile, the high-low temperature flue gas in the furnace is mixed without a high-low temperature mixing flue, so that the space is not occupied, the heat dissipation loss is avoided, the air leakage is not increased, and the mixing effect is good.

3. The utility model discloses folding the cigarette wall behind furnace and upwards falling into several sections and drawing into two rows of mixed cigarette walls that form, every section width of this mixed cigarette wall is more than 500mm, and arranges around and staggers out and arrange, has strengthened horizontal flue gas and has mixed the effect, is favorable to the denitration reaction.

4. The utility model discloses some diaphragm type wall surface designs more than the cigarette wall of book in the front have fire-resistant insulating layer, can effectively reduce upper portion furnace heating surface heat absorption, increase the furnace space that is fit for SNCR denitration flue gas temperature, are favorable to the SNCR denitration reaction.

Drawings

FIG. 1 is a schematic view of the flue gas direction of the present invention;

FIG. 2 is a schematic sectional view of the structure of the present invention;

FIG. 3 is an enlarged view of the part A of FIG. 2;

fig. 4 is an enlarged schematic view of the part B of fig. 2.

The numbers in the figures are as follows:

1-a boiler body; 2-front hearth; 3-rear hearth; 4-water cooling the flue; 5-high temperature convection heating surface; 6-connecting a pipeline; 7-an SCR reactor; 8-a catalyst; 9-low temperature convection heating surface; 10-a combustion device; 12-front wall; 13-intermediate partition wall; 14-rear wall; 15-side walls; 16-a denitrifier nozzle; 17-front folding smoke wall; 18-front top wall; 19-a refractory insulating layer; 20-mixed smoke wall; 21-rear folding wall; 22-rear top wall; 23- -flue gas short circuit port; 24-a smoke temperature regulating gate; 25-water cooling the side wall of the flue; 26-Water cooling flue back wall.

Detailed Description

The embodiments of the present invention will be further explained with reference to the accompanying drawings: the following examples are illustrative and not intended to be limiting, and the scope of the present invention is not limited by the following examples.

An industrial boiler capable of effectively denitrating in a boiler, which is shown in figure 1, comprises a boiler body 1 and a combustion device 10, wherein a hearth is arranged in the boiler body, and the combustion device is arranged at the lower part of the hearth in the boiler body. The combustion equipment can be a chain grate, a reciprocating grate, a pulverized coal burner, a gas burner and the like, and the attached drawing of the embodiment takes a chain grate hot water boiler as an example for description. The furnace in the boiler body is of a membrane wall structure, the furnace is formed by a front wall 12, a rear wall 14 and side walls 15 at two sides and is made into a front furnace 2 and a rear furnace 3 by adopting a middle partition wall 13, smoke sequentially passes through the front furnace, the rear furnace and a furnace outlet 11 to enter a water-cooling flue 4, and the smoke enters a low-temperature convection heating surface 9 from a connecting pipeline 6 after passing through a high-temperature convection heating surface 5 arranged in the water-cooling flue and then is discharged out of the boiler body. When the emission of NOx in the flue gas needs to be reduced, an SCR denitration reactor 7 is arranged between the water-cooling flue and the low-temperature convection heating surface, and a catalyst 8 is arranged, so that the flue gas enters the low-temperature convection heating surface after being subjected to denitration through the SCR denitration reactor.

The innovation point of the utility model is mainly embodied in the following aspects, see fig. 2:

1. the two sides of the front hearth and (or) the front wall are respectively provided with a row of denitrifier nozzles 16 at the height of the front smoke-folding wall, the upper row and the lower row of denitrifier nozzles are matched for use, the lower row and the middle row of denitrifier nozzles are used when the boiler operates at low load, the upper row and the lower row of denitrifier nozzles are used when the boiler operates at middle and high load, and the denitrifier nozzles (not shown in the drawing of the embodiment) can be arranged at the two sides of the rear hearth and (or) the rear position of the outlet of the high-temperature economizer to supplement denitrifier for SCR denitration. The height of the front folding smoke wall is at a high limit value suitable for the temperature of the smoke of SNCR denitration reaction, and is optimally about 1100 ℃.

2. The middle part of the front wall forming the front hearth protrudes backwards to form a front smoke folding wall 17 of the hearth, and then the upper part of the front wall is bent backwards to form a front top wall 18 of the hearth; the upper part of the middle partition wall is bent forwards to form a rear smoke folding wall 21 of the hearth, and then the rear smoke folding wall is upwards divided into a plurality of sections and pulled into two rows of mixed smoke walls 20; the upper part of the back wall is bent forwards to form a hearth back top wall 22, the lower part of the back wall is a hearth outlet, and the flue gas is reversely bent by 180 degrees from the hearth outlet and enters the water-cooling flue. Therefore, the front smoke folding wall, the rear smoke folding wall, the front top wall and the rear top wall of the hearth form an inverse S-shaped smoke flow path, which is shown by a curve of a left arrow in the attached figure 1; a reverse J-shaped flue gas flow is formed by the lower part of the rear hearth and the lower part of the water-cooling flue, and is shown by a curve of a right arrow in the attached drawing 1, so that the flue gas stroke is prolonged, the longitudinal flue gas mixing effect is enhanced, the denitration reaction is facilitated, the SNCR denitration reaction efficiency can be improved to about 60%, and the effect is very obvious.

3. The rear folding smoke wall of the hearth is upwards divided into a plurality of sections and is pulled into two rows of formed mixed smoke walls, the width of each section is more than 500mm, the front section and the rear section are arranged in a staggered mode, the transverse smoke mixing effect is enhanced, and the denitration reaction is facilitated. The position of the mixed smoke wall is set at the middle value of the smoke temperature suitable for SNCR denitration reaction, and the temperature is optimally about 950 ℃.

4. A part of the film type wall surface above the front smoke folding wall of the hearth is provided with a fireproof heat insulation layer 19, see fig. 3, so that the heat absorption of the heating surface of the upper hearth is reduced, the hearth space suitable for the temperature of SNCR denitration flue gas is increased, and the SNCR denitration reaction is facilitated.

5. The water cooling flue behind the rear wall of the hearth is of a membrane wall structure and consists of the rear wall of the hearth, a rear wall 26 of the water cooling flue and a side wall 25, a flue gas short-circuit opening 23 is formed in the upper part of the rear wall of the hearth along the whole width of the hearth, and a flue gas temperature regulating door 24 is arranged in the rear wall of the hearth, as shown in figure 4. Under the control of the smoke temperature adjusting door, high-temperature smoke at the upper part of the hearth can be properly short-circuited to low-temperature smoke at the upper part of the water-cooling flue, and the smoke temperature at the smoke outlet of the water-cooling flue can be kept within a temperature range suitable for SCR denitration requirements within a 60% boiler load change range. The flue gas short-circuit mouth can set up one along whole water-cooling flue width, also can evenly divide into a plurality of settings along whole flue width. The water-cooled wall of the flue gas short circuit port part is a light tube water-cooled wall, and a gap between every two light tubes forms a flue gas short circuit port. The smoke temperature adjusting door is made of heat-resistant materials, and the opening degree of the smoke temperature adjusting door can be adjusted.

The high-temperature convection heating surface arranged in the water-cooling flue can be a flag type heating surface, a coiled pipe heating surface or other convection heating surfaces. The outlet smoke temperature of the high-temperature convection heating surface is designed to be slightly lower than the upper limit temperature suitable for the SCR denitration reaction temperature, so that the SCR catalyst overtemperature accident can not occur.

6. The low-temperature convection heating surface communicated and connected with the rear part of the connecting pipeline can be an economizer or an economizer and an air preheater or other boiler convection heating surfaces.

Claims

1. The utility model provides an industrial boiler that can effectively denitrate in stove, including the boiler body, combustion apparatus, this internal furnace that is provided with of boiler, combustion apparatus arranges the lower part of this internal furnace of boiler in, this internal furnace of boiler is the diaphragm type wall structure, by the side wall formation of front wall, back wall and both sides and adopt intermediate wall to make it constitute preceding furnace and back furnace, the flue gas loops through preceding furnace, back furnace, the furnace export gets into the water-cooling flue, get into low temperature convection heating surface from the connecting tube behind the high temperature convection heating surface that sets up in the water-cooling flue again, then discharge the boiler body, its characterized in that: the middle part of the front wall forming the front hearth protrudes backwards to form a front smoke folding wall of the hearth, and the upper part of the front wall is bent backwards to form a front top wall of the hearth; the upper part of the middle partition wall is bent forwards to form a rear smoke folding wall of the hearth, and the rear smoke folding wall is upwards divided into a plurality of sections and pulled into two rows of mixed smoke walls; the upper part of the rear wall is bent forwards to form a hearth rear top wall, the lower part of the rear wall is a hearth outlet, flue gas reversely bends 180 degrees from the hearth outlet and enters the water-cooling flue, so that the front smoke-bending wall, the rear smoke-bending wall, the front top wall and the rear top wall of the hearth form an inverse S-shaped flue gas flow, and the rear hearth and the lower part of the water-cooling flue form an inverse J-shaped flue gas flow.

2. The industrial boiler capable of effective denitration in the furnace according to claim 1, wherein: a row of denitrifier nozzles are respectively designed on the two sides of the front hearth and/or the front wall, the height position of the front smoke-folding wall and the hearths above and below the front smoke-folding wall, three rows of denitrifier nozzles are matched for use, the lower row of denitrifier nozzles and the middle row of denitrifier nozzles are used when the boiler operates at low load, and the upper row of denitrifier nozzles and the middle row of denitrifier nozzles are used when the boiler operates at medium and high load.

3. The industrial boiler capable of effective denitration in the furnace according to claim 1, wherein: the rear smoke folding wall of the hearth is upwards divided into a plurality of sections which are drawn into two rows to form a mixed smoke wall, the width of each section is more than 500mm, and the front and rear sections are arranged in a staggered way.

4. The industrial boiler capable of effective denitration in the furnace according to claim 1, wherein: a fireproof heat insulation layer is designed on the surface of the membrane wall above the front smoke folding wall of the hearth.

5. The industrial boiler capable of effective denitration in the furnace according to claim 1, wherein: the water cooling flue behind the rear wall of the hearth is of a membrane wall structure and consists of the rear wall of the hearth, the rear wall of the water cooling flue and a side wall, a flue gas short circuit port is formed in the upper portion of the rear wall of the hearth along the width of the whole hearth, and a flue gas temperature adjusting door is arranged on the upper portion of the rear wall of the hearth.

6. The industrial boiler capable of effectively denitrating in the furnace according to claim 5, wherein: the flue gas short circuit port is arranged along the width of the whole water-cooling flue, or is uniformly divided into a plurality of ports along the width of the whole flue; the water-cooled wall of the flue gas short circuit port part is a light tube water-cooled wall, and a gap between every two light tubes forms a flue gas short circuit port; the smoke temperature adjusting door is made of heat-resistant materials, and the opening degree of the smoke temperature adjusting door can be adjusted.

7. The industrial boiler capable of effective denitration in the furnace according to claim 1, wherein: the high-temperature convection heating surface arranged in the water-cooling flue is a flag type heating surface or a convection heating surface of a coiled pipe heating surface, and the outlet smoke temperature of the high-temperature convection heating surface is designed to be slightly lower than the upper limit temperature suitable for the SCR denitration reaction temperature.

8. The industrial boiler capable of effective denitration in the furnace according to claim 1, wherein: when the flue gas needs to be discharged with lower NOx, an SCR denitration reactor is arranged between the water-cooling flue and the low-temperature convection heating surface, and a catalyst is arranged, so that the flue gas enters the low-temperature convection heating surface after being denitrated by the SCR denitration reactor.