Air leakage and ash leakage prevention through type water-cooling long spray gun for SNCR (selective non-catalytic reduction) denitration

Abstract

The invention belongs to the technical field of flue gas denitration, and discloses a gas leakage and ash leakage prevention through type water-cooling long spray gun for SNCR denitration, which comprises a spray gun body, the head of the spray gun body is fixed on a water-cooling wall tube on one side of a furnace wall through a fixing piece; the furnace wall sleeve is embedded and fixed on a water cooling wall tube on the other side of the furnace wall, and the tail part of the spray gun body penetrates out of the furnace wall sleeve; the high-temperature-resistant expansion joint is arranged at the tail part of the spray gun body in a sleeving manner, and the spray gun body is fixedly connected with the furnace wall sleeve through the high-temperature-resistant expansion joint. The high-temperature-resistant expansion joint is arranged outside the spray gun, and when the boiler is started and stopped or the load changes, the water cooling wall generates transverse expansion, the high-temperature-resistant expansion joint can generate corresponding transverse expansion, so that the spray gun can adapt to the transverse expansion of the water cooling wall of the boiler, the head of the spray gun is prevented from falling off, and meanwhile the sealing effect is achieved; and the phenomena of air suction caused by negative pressure of the hearth or ash leakage caused by positive pressure of the hearth are prevented, and a good environment-friendly effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas denitration, and more particularly to a gas leakage and ash leakage prevention through-type water-cooled long spray gun for SNCR denitration. Background Art

[0002] SNCR denitrification is a denitrification technology commonly used in power plant boilers. SNCR stands for selective non-catalytic reduction. Selective non-catalytic reduction refers to the reduction of nitrogen oxides in flue gas to harmless nitrogen and water by injecting a reducing agent within the "temperature window" suitable for denitrification reaction without the action of a catalyst. This technology generally uses ammonia, urea or amino acid as a reducing agent to reduce NO X The reducing agent only reacts with NO in the flue gas. X The denitrification spray gun is an important part of SNCR denitrification. Its main purpose is to spray the denitrification reducing agent into the temperature appropriate area through compressed air to achieve the purpose of denitrification.

[0003] The water-cooled denitrification spray gun is a product suitable for the SNCR denitrification system. The original water-cooled spray gun is divided into: an outer protective layer (insulated and wear-resistant), an outer tube, an internal reducing agent inner tube, an internal cooling water pipe, etc. The outer tube is provided with a mixer (with a reducing agent inlet and a compressed air inlet), a cooling water inlet and a cooling water outlet. The water-cooled spray gun is arranged in the area with a higher boiler temperature (>800℃), and absorbs a large amount of heat during operation, so the spray gun is cooled by continuously injecting water into the outer tube of the spray gun, and the hot water after heat absorption is discharged through the cooling water outlet. A mixer is configured at the tail of the spray gun, and there are a reducing agent inlet and a compressed air inlet on the mixer. The denitrification reducing agent and the compressed air are mixed by the mixer (the compressed air plays a role in assisting the atomization of the liquid reducing agent) and enter the reducing agent inner tube inside the spray gun, and then are ejected through the nozzle between the reducing agent inner tube and the outer tube into the boiler furnace to realize the denitrification reaction (such as the prior art CN115672004A-A fluidized bed boiler SNCR ultra-low emission denitrification device).

[0004] The head of the spray gun is usually fixed to the boiler water-cooled wall tube by screws or anchors, and the tail of the spray gun passes through the water-cooled wall tube on the other side of the boiler and extends out of the boiler. However, when the boiler is started or stopped or the load changes, the water-cooled wall tube of the boiler expands horizontally, which often causes the head of the spray gun to fall off and affect its use. In addition, the sealing effect between the spray gun and the wall is not good, which will cause air suction caused by negative pressure in the furnace or ash leakage caused by positive pressure in the furnace. In addition, to ensure the cooling effect, the cooling water can only be discharged from the outlet when it fills the water pipe inside the outer tube. During the actual operation, part of the water pipe will be vaporized, and the vaporized steam will fill the water pipe and cannot be discharged in time, causing a certain pressure inside the water pipe, which will lead to poor cooling water discharge and reduced water intake, which will cause poor cooling effect of the spray gun. In severe cases, it may cause deformation of the spray gun, or even directly cause the spray gun to be unable to continue to be used, seriously affecting the life of the spray gun.

[0005] Therefore, how to provide a spray gun that can adapt to the lateral expansion of the boiler water-cooled wall tubes, avoid the spray gun head from falling off and affecting the denitrification effect, and at the same time play a sealing role to prevent air suction caused by negative pressure in the furnace or ash leakage caused by positive pressure in the furnace, as well as ensure smooth cooling water inlet and return, improve the cooling effect, prevent the spray gun from bending and deforming due to insufficient cooling water, extend the life of the spray gun, and have a good economical SNCR denitrification anti-leakage and anti-ash through-type long water-cooled spray gun is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0006] In view of this, the present invention provides a spray gun that can adapt to the lateral expansion of the boiler water-cooled wall tube, avoid the spray gun head from falling off and affecting the denitrification effect, and at the same time play a sealing role to prevent air suction caused by negative pressure in the furnace or ash leakage caused by positive pressure in the furnace, as well as ensure the smooth flow of cooling water inlet and return, improve the cooling effect, prevent the spray gun from bending and deforming due to insufficient cooling water, extend the service life of the spray gun, and have a good economical anti-gas and ash leakage through-type long spray gun for SNCR denitrification.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A gas leakage and ash leakage prevention through-type water-cooled long spray gun for SNCR denitrification, comprising:

[0009] A spray gun body, the head of which is fixed to a water-cooled wall tube on one side of the furnace wall through a fixing member;

[0010] A furnace wall sleeve, wherein the furnace wall sleeve is embedded in the water-cooled wall tube on the other side of the furnace wall, and the tail of the spray gun body passes through the furnace wall sleeve;

[0011] A high temperature resistant expansion joint is sleeved on the tail of the spray gun body, and the spray gun body is fixedly connected to the furnace wall sleeve through the high temperature resistant expansion joint.

[0012] It can be seen from the above technical scheme that, compared with the prior art, the present invention discloses a kind of anti-leakage and anti-ash leakage through-type water-cooled long spray gun for SNCR denitrification, and the outside of the spray gun is provided with a high-temperature resistant expansion joint. When the water-cooled wall expands laterally when the boiler is started or stopped or the load changes, the high-temperature resistant expansion joint can produce corresponding lateral expansion and contraction, so that the spray gun can adapt to the lateral expansion of the boiler water-cooled wall and prevent the spray gun head from falling off. At the same time, it plays a sealing role to prevent the suction caused by the negative pressure of the furnace or the ash leakage caused by the positive pressure of the furnace, and has a good environmental protection effect.

[0013] Furthermore, end plates and flange sleeves are fixed on both sides of the high-temperature resistant expansion joint, respectively; the end plate is sleeved on the tail of the spray gun body; the flange sleeve is sleeved on the tail of the spray gun body; and the flange sleeve is fixedly connected to the flange plate on the furnace wall sleeve.

[0014] The beneficial effect of adopting the above technical solution is: when the water-cooled wall expands laterally when the boiler is started or stopped or the load changes, the expanded wall drives the furnace wall casing to move laterally, and the furnace wall casing drives the high-temperature resistant expansion joint to expand and contract laterally through the flange casing, thereby effectively preventing the spray gun head from falling off due to the external force exerted on it by the laterally expanding wall.

[0015] Furthermore, the spray gun body comprises:

[0016] An outer tube, the head end of the outer tube is fixed to the water-cooled wall tube on one side of the furnace wall through the fixing member, the tail of the outer tube passes through the flange sleeve, the end plate is sleeved on the tail of the outer tube, the high-temperature expansion joint and the flange sleeve are both sleeved on the tail of the outer tube, and a plurality of nozzles are arranged at intervals on the outer tube located inside the furnace;

[0017] An inner reducing agent tube, the inner reducing agent tube is located inside the outer tube, an inlet of the inner reducing agent tube is connected to a mixer, the mixer is provided with a compressed air inlet and a reducing agent inlet, and the inner reducing agent tube is connected to the plurality of nozzles;

[0018] Wherein, the space between the outer tube and the reducing agent inner tube is a water cavity, and the tail of the outer tube is provided with a water inlet and a water outlet communicating with the water cavity; or,

[0019] A U-shaped cooling water pipe is arranged inside the outer tube, one end of the U-shaped cooling water pipe is the water inlet, and the other end is the water outlet.

[0020] The beneficial effect of adopting the above technical scheme is: the denitrification reductant and compressed air are mixed in the mixer and enter the reductant inner tube inside the spray gun, and then are sprayed into the boiler furnace through the nozzle between the reductant inner tube and the outer tube to realize the denitrification reaction, while the external cold water enters the spray gun to cool it.

[0021] The spray gun of the present invention provides two water cooling methods. The first method is to use the internal space of the outer tube directly as a water cavity, so that the cold water directly exchanges heat with the outer tube, which can greatly improve the cooling efficiency and effect of the outer tube; the second method is to adopt the traditional method of placing a U-shaped cooling water pipe inside the outer tube. This method can also achieve cooling of the outer tube, but its effect is slightly worse than the first method.

[0022] Furthermore, a pressure relief pipe connected to the water cavity or the U-shaped cooling water pipe is provided at the tail end of the outer pipe.

[0023] The beneficial effects of adopting the above technical scheme are: the water vapor generated in the water cavity or the U-shaped cooling water pipe can be released through the pressure relief pipe, thereby preventing pressure buildup inside the spray gun, ensuring smooth inlet and return of cooling water, improving the cooling effect, preventing the spray gun from bending and deforming due to insufficient cooling water, etc., extending the life of the spray gun and achieving good economy.

[0024] Furthermore, a spray gun support is fixed to the head end of the outer tube, and the spray gun support is fixed to the water-cooled wall tube on one side of the furnace wall through the fixing piece, and the head end of the outer tube is inserted into the slot on the spray gun support.

[0025] The beneficial effect of adopting the above technical solution is: during installation, the spray gun support is first fixed to the water-cooled wall tube through the fixing parts, and then the head end of the outer tube is directly plugged into the slot on the spray gun support to achieve rapid disassembly and assembly of the gun body.

[0026] Furthermore, a heat-insulating layer is provided on the outer side of the furnace wall.

[0027] The beneficial effect of adopting the above technical solution is: improving the thermal insulation performance of the furnace body. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0029] Figure 1 The present invention provides a schematic structural diagram of a gas leakage and ash leakage-proof through-type water-cooled long spray gun for SNCR denitrification. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, the embodiment of the present invention discloses a gas leakage and ash leakage prevention through-type water-cooled long spray gun for SNCR denitration, comprising:

[0032] The spray gun body 100, the head of the spray gun body 100 is fixed to the water-cooled wall tube 13 on one side of the furnace wall through a fixing member 16;

[0033] The furnace wall sleeve 14 is embedded in the water-cooled wall tube 13 on the other side of the furnace wall, and the tail of the spray gun body 100 passes through the furnace wall sleeve 14;

[0034] The high temperature resistant expansion joint 10 is sleeved on the tail of the spray gun body 100 , and the spray gun body 100 is fixedly connected to the furnace wall sleeve 14 through the high temperature resistant expansion joint 10 .

[0035] In the above embodiment, the end plate 9 and the flange sleeve 2 are respectively fixed on both sides of the high temperature resistant expansion joint 10, the end plate 9 is fixed on the tail of the spray gun body 100, the flange sleeve 2 is sleeved on the tail of the spray gun body 100, and the flange sleeve 2 is fixedly connected to the flange plate on the furnace wall sleeve 14.

[0036] In some embodiments, the spray gun body 100 includes:

[0037] An outer tube 1, the head end of the outer tube 1 is fixed to a water-cooled wall tube 13 on one side of the furnace wall through a fixing member 16, the tail of the outer tube 1 passes through a flange sleeve 2, an end plate 9 is sleeved (for example, welded) on the tail of the outer tube 1, a high-temperature expansion joint 10 and a flange sleeve 2 are sleeved on the tail of the outer tube 1, and a plurality of nozzles 11 are arranged at intervals on the outer tube 1 located inside the furnace;

[0038] The reducing agent inner tube is located inside the outer tube 1, and a mixer 5 is connected to the inlet of the reducing agent inner tube. The mixer 5 is provided with a compressed air inlet 6 and a reducing agent inlet 4. The reducing agent inner tube is connected to a plurality of nozzles 11;

[0039] The space between the outer tube 1 and the reducing agent inner tube is a water cavity, and the tail of the outer tube 1 is provided with a water inlet 7 and a water outlet 8 connected to the water cavity; or,

[0040] A U-shaped cooling water pipe is arranged inside the outer tube 1 , one end of the U-shaped cooling water pipe is a water inlet 7 , and the other end is a water outlet 8 .

[0041] The tail of the outer tube 1 is provided with a pressure relief pipe 3 which is connected with the water cavity or the U-shaped cooling water pipe.

[0042] A spray gun support 15 is fixed to the head end of the outer tube 1 , and the spray gun support 15 is fixed to the water-cooled wall tube 13 on one side of the furnace wall through a fixing member 16 (which can be a bolt or an anchor), and the head end of the outer tube 1 is inserted into the slot on the spray gun support 15 .

[0043] A heat-insulating layer 12 is provided on the outer side of the furnace wall.

[0044] The present invention provides a pressure relief pipe so that the water-cooled spray gun can discharge steam or other gases generated by the evaporation of cooling water inside the spray gun in time, thereby preventing pressure buildup inside the spray gun, ensuring smooth inflow and return of cooling water, improving the cooling effect, preventing the spray gun from bending and deforming due to insufficient cooling water, and extending the service life of the spray gun with good economy.

[0045] In addition, a retractable high-temperature resistant expansion joint is provided so that the spray gun can adapt to the lateral expansion of the boiler water-cooled wall to prevent the spray gun head from falling off. At the same time, the high-temperature resistant expansion joint, end plate, furnace wall sleeve and flange sleeve can play a sealing role between the spray gun and the wall to prevent air suction caused by negative pressure in the furnace or ash leakage caused by positive pressure in the furnace, and has a good environmental protection effect.

[0046] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0047] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A gas leakage and ash leakage prevention through-type water-cooled long spray gun for SNCR denitrification, characterized in that: include: A spray gun body (100), wherein the head of the spray gun body (100) is fixed to a water-cooled wall tube (13) on one side of the furnace wall via a fixing member (16); A furnace wall sleeve (14), wherein the furnace wall sleeve (14) is embedded in the water-cooled wall tube (13) on the other side of the furnace wall, and the tail of the spray gun body (100) is arranged to pass through the furnace wall sleeve (14); A high temperature resistant expansion joint (10) is sleeved on the rear portion of the spray gun body (100), and the spray gun body (100) is fixedly connected to the furnace wall sleeve (14) via the high temperature resistant expansion joint (10).

2. The anti-gas and ash leakage through-type water-cooled long spray gun for SNCR denitrification according to claim 1 is characterized in that: An end plate (9) and a flange sleeve (2) are fixed to both sides of the high-temperature resistant expansion joint (10), respectively; the end plate (9) is sleeved on the rear portion of the spray gun body (100); the flange sleeve (2) is sleeved on the rear portion of the spray gun body (100); and the flange sleeve (2) is fixedly connected to a flange plate on the furnace wall sleeve (14).

3. The anti-gas and ash leakage through-type water-cooled long spray gun for SNCR denitrification according to claim 2 is characterized in that: The spray gun body (100) comprises: An outer tube (1), the head end of the outer tube (1) being fixed to a water-cooled wall tube (13) on one side of the furnace wall via the fixing member (16), the tail end of the outer tube (1) passing through the flange sleeve (2), the end plate (9) being sleeved on the tail end of the outer tube (1), the high temperature resistant expansion joint (10) and the flange sleeve (2) both being sleeved on the tail end of the outer tube (1), and a plurality of nozzles (11) being arranged at intervals on the outer tube (1) located inside the furnace; a reducing agent inner tube, the reducing agent inner tube being located inside the outer tube (1), the reducing agent inner tube inlet being connected to a mixer (5), the mixer (5) being provided with a compressed air inlet (6) and a reducing agent inlet (4), the reducing agent inner tube being in communication with the plurality of nozzles (11); Wherein, the space between the outer tube (1) and the reducing agent inner tube is a water cavity, and the tail of the outer tube (1) is provided with a water inlet (7) and a water outlet (8) respectively connected to the water cavity; or, A U-shaped cooling water pipe is provided inside the outer tube (1), one end of the U-shaped cooling water pipe being the water inlet (7) and the other end being the water outlet (8).

4. The anti-gas and ash leakage through-type water-cooled long spray gun for SNCR denitrification according to claim 3 is characterized in that: The tail of the outer tube (1) is provided with a pressure relief pipe (3) which is in communication with the water cavity or the U-shaped cooling water pipe.

5. A gas leakage and ash leakage prevention through-type water-cooled long spray gun for SNCR denitrification according to claim 3 or 4, characterized in that: A spray gun support (15) is fixed to the head end of the outer tube (1), and the spray gun support (15) is fixed to a water-cooled wall tube (13) on one side of the furnace wall via the fixing member (16), and the head end of the outer tube (1) is inserted into a slot on the spray gun support (15).

6. A gas leakage and ash leakage prevention through-type water-cooled long spray gun for SNCR denitrification according to any one of claims 1 to 4, characterized in that: A heat-insulating layer (12) is provided on the outer side of the furnace wall.

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