CN213078045U

CN213078045U - SCR spouts ammonia system with reinforceing stifled nozzle structure of preventing that mixes

Info

Publication number: CN213078045U
Application number: CN202021231194.3U
Authority: CN
Inventors: 蔡明坤; 王勇; 薛佳立
Original assignee: Shanghai Boiler Works Co Ltd
Current assignee: Shanghai Boiler Works Co Ltd
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2021-04-30
Anticipated expiration: 2030-06-29

Abstract

The utility model discloses a SCR spouts ammonia system with reinforceing and mix stifled nozzle structure of preventing, fix the shower nozzle lid on the port on the direct jet including the lower extreme, the upper end of shower nozzle lid is seal structure, and the equipartition has a plurality of orifices around the shower nozzle lid side. The utility model discloses be fit for reforming transform at labour unit ammonia injection grid system, add cage shower nozzle lid on the straight spout of traditional reductant, change the reductant directly spout into the side and spout, adopt a plurality of evenly distributed of multirow in the orifice of shower nozzle side, can cover the perpendicular cross section direction of former straight shower nozzle axis whole week, blowout direction and flue gas flow direction basic orthogonality, greatly increased the mixing region scope of reductant and flue gas, mixing intensity obviously improves, the dispersed concentration of ammonia in the flue gas is also more even, be favorable to improving denitration efficiency and reducing ammonia escape rate, can prevent effectively that the ash that subsides in the boiler shutdown stage flue gas from getting into the reductant spout and causing the jam, thereby the maintenance work volume of ammonia spraying mouth has been avoided.

Description

SCR spouts ammonia system with reinforceing stifled nozzle structure of preventing that mixes

Technical Field

The utility model relates to a SCR (selective catalytic reduction) spouts ammonia system with reinforceing and mix stifled nozzle structure of preventing belongs to boiler SCR deNOx systems technical field.

Background

The reducing agent shower nozzle of SCR ammonia injection grid of traditional design is very simple, and most direct adoption sets up the form of straight shower nozzle from the reducing agent supply pipe, and the blowout axis of straight shower nozzle is many unanimous with the flue gas flow direction, and reducing agent pressure is higher than the flue gas, and the reducing agent is directly spout from the spout, needs to rely on the entrainment effect and the flue gas mixing of blowout air current, and the mixing distance that needs is longer, and the flue segment length that needs is also longer. For reducing this mixed length, the part design changes the shower nozzle axis into and is certain angle with the flue gas, but the reductant gas still is for following a big spout blowout, need to set up the static mixer that the structure is complicated for further improving the mixed degree of consistency of flue gas and reductant in the flue, the design cost of system has been increased, the spout is when up, at unit shutdown phase, because the spout bore is great, the ash deposit falls into the spout in the flue gas, can absorb damp caking the time of having a specified duration, lead to the nozzle to block up, lead to the unit to need manual cleaning before resuming the operation after shutting down for a long time, the maintenance work volume of having increased a lot of operations.

Disclosure of Invention

The to-be-solved technical problem of the utility model is: how to avoid or reduce the ash deposition in the flue gas from falling into the direct injection port with the upward nozzle.

In order to solve the technical problem, the technical scheme of the utility model provides a SCR spouts ammonia system with reinforceing and mix anti-blocking nozzle structure is provided, its characterized in that, including the shower nozzle lid that the lower extreme was fixed on the port of straight spout upper end, the upper end of shower nozzle lid is seal structure, and the equipartition has a plurality of orifices around the shower nozzle lid side.

Preferably, the nozzle cover comprises a top cover and a cylinder body, the top cover is fixed at the upper end of the cylinder body, the lower end of the cylinder body is fixed at the upper end of the straight nozzle, and the plurality of nozzle holes are uniformly distributed on the cylinder body.

Preferably, the plurality of spray holes are divided into at least two rows and are uniformly distributed on the cylinder body.

Preferably, the adjacent rows of the nozzle holes on the cylinder are staggered, and the ejection angles of all the nozzle holes cover the whole circumference on a projection plane perpendicular to the axial direction of the direct injection port.

Preferably, the total ejection area of all said orifices is greater than 50% of the cross-sectional area of the straight orifice.

Preferably, the spray holes are transversely arranged kidney-shaped holes.

Preferably, the inner side of the lower end of the cylinder body is provided with a step, the step is propped against the port at the upper end of the direct injection port, and the port at the upper end of the direct injection port is wrapped by the outer side of the lower end of the cylinder body.

Preferably, the shape of the top cover is a flat plate or a conical or curved surface.

The utility model discloses be fit for reforming transform at labour unit ammonia injection grid system, add cage shower nozzle lid on the straight spout of traditional reductant, change the reductant directly spout into the side and spout, adopt a plurality of evenly distributed of multirow in the orifice of shower nozzle side, can cover the perpendicular cross section direction of former straight shower nozzle axis all around, blowout direction and flue gas flow direction basic orthogonality, greatly increased the mixing region scope of reductant and flue gas, mixing intensity obviously improves, the dispersed concentration of ammonia in the flue gas is also more even, be favorable to improving denitration efficiency and reducing ammonia escape rate, reductant mixing section flue length also can suitably shorten, the utility model discloses a shower nozzle project organization can effectively prevent to subside the ash and get into the reductant spout and arouse the jam in the boiler shutdown stage flue gas to the maintenance work load of ammonia injection mouth has been avoided.

Drawings

FIG. 1 is a schematic position diagram of an enhanced mixing anti-blocking nozzle structure for an SCR ammonia injection system;

FIG. 2 is a schematic diagram of the arrangement positions of the spray holes in the adjacent rows (the upper layer structure of the top cover in FIG. 1);

fig. 3 is a schematic diagram of the arrangement positions of the spray holes in the adjacent rows (the lower layer structure of the top cover in fig. 1).

Detailed Description

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

As shown in fig. 1, the reducing agent nozzle of the conventional design is a straight nozzle 4 mounted on a reducing agent supply pipe 5, and the axial direction of the straight nozzle 4 is substantially parallel to the flow direction of the flue gas. The utility model relates to a SCR spouts ammonia system with reinforceing and mix stifled nozzle structure of preventing, increase cage shower nozzle lid in the top of current straight spout 4, cage shower nozzle lid comprises top cap 1 and barrel 2, top cap 1 and barrel 2 welding link to each other or make into a whole part, top cap 1 is last not trompil, top cap 1's shape can be dull and stereotyped or adopt toper, curved surface type etc, it has several rows of orifice 3 to open on barrel 2, barrel 2's lower extreme and the upper end fixed connection (spot welding or threaded connection all can) of directly spout 4.

In this embodiment, the cylinder 2 is provided with 2 rows of spray holes 3, and the spray holes 3 are transversely arranged waist-shaped holes. The inner side of the lower end of the cylinder body 2 is provided with a step which is supported on the port at the upper end of the straight spout 4, and the port at the upper end of the straight spout 4 is wrapped by the outer side of the lower end of the cylinder body 2.

As shown in fig. 2 and 3, the rows of adjacent nozzle holes 3 on the cylinder 2 are offset from each other, and the ejection angles of all the nozzle holes 3 need to cover the entire circumference (i.e., the sum of the ejection angles of all the nozzle holes 3 is equal to or greater than 360 °) on a projection plane perpendicular to the axial direction of the direct injection port 4. Considering the need to reduce the reductant nozzle orifice resistance loss, the total ejection area of all the nozzle orifices 3 needs to be greater than 50% of the cross-sectional area of the straight nozzle orifice 4.

The reducing agent is brought in by the vortex effect of the flue gas flowing through the area right above the straight nozzle 4, so that the uniform mixing of the reducing agent and the flue gas on the cross section of the whole flue is ensured.

Claims

1. The utility model provides a SCR ammonia injection system is with stifled nozzle structure is prevented with intensive mixing which characterized in that, includes that the lower extreme is fixed the shower nozzle lid on straight spout (4) upper end port, and the upper end of shower nozzle lid is seal structure, and the equipartition has a plurality of orifice (3) around the shower nozzle lid side.

2. The structure of claim 1, wherein the nozzle cover comprises a top cover (1) and a barrel (2), the top cover (1) is fixed on the upper end of the barrel (2), the lower end of the barrel (2) is fixed on the upper end of the straight nozzle (4), and the plurality of nozzles (3) are uniformly distributed on the barrel (2).

3. The structure of claim 2, wherein the plurality of spray holes (3) are divided into at least two rows and uniformly distributed on the cylinder (2).

4. The structure of claim 3, wherein the adjacent rows of injection holes (3) on the cylinder (2) are staggered from each other, and the injection angles of all the injection holes (3) cover the whole circumference on the projection plane perpendicular to the axial direction of the direct injection port (4).

5. An intensified mixing anti-blocking nozzle structure for an SCR ammonia spraying system according to claim 4, characterized in that the total spraying area of all the spraying holes (3) is more than 50% of the cross-sectional area of the straight nozzle (4).

6. The structure of the enhanced mixing anti-blocking nozzle for the SCR ammonia spraying system as defined in any one of claims 1 to 5, wherein the spray holes (3) are transversely arranged kidney-shaped holes.

7. The structure of claim 2, wherein the inner side of the lower end of the cylinder (2) is provided with a step which is supported on the upper end port of the straight spout (4), and the outer side of the lower end of the cylinder (2) wraps the upper end port of the straight spout (4).

8. An intensified mixing anti-blocking nozzle structure for an SCR ammonia spraying system according to claim 2, characterized in that the top cover (1) is flat or conical or curved.