CN111097268B - A composite laminated reducing agent high-speed injection device - Google Patents

Abstract

The present invention relates to a composite laminated high-speed reducing agent injection device, which is made of high-temperature resistant and wear-resistant materials, and includes a cylindrical shell, a laminated composite nozzle with nozzles of reducing agent A and reducing agent B, and channels and swing driving mechanisms for reducing agent A and reducing agent B. The injection device is installed on the furnace wall of the boiler combustion zone, and the composite nozzle is installed on the shell tube mouth with a limit shaft, and can swing up and down. The reducing agent is injected into the main combustion zone of the reducing atmosphere through the respective nozzles to participate in the low-nitrogen combustion with the function of suppressing the generation of NOx and reducing the generated NOx. At the same time, the high-speed airflow ejected from the nozzle is conducive to the full mixing of the reducing agent and the flue gas, optimizing the flow field, avoiding the generation of local high temperature, reducing thermal NOx, and realizing ultra-low NOx emission in the flue gas. The reducing agent B airflow can also play a role in preventing the nozzle from slagging and the reducing agent A from being oxidized. The structure is simple and reasonable, the operation is reliable and the service life is long, and it can meet the use requirements of being set on the furnace wall and injecting multiple reducing agents at the same time.

Description

A composite laminated reducing agent high-speed injection device

Technical Field

The invention relates to the technical field of boiler combustion devices, in particular to a composite laminated reducing agent high-speed injection device which is suitable for injecting multiple reducing agents simultaneously as needed into a boiler high-temperature combustion zone.

Background technique

In response to the ultra-low standard requirement of less than 50mg/Nm3 proposed by my country's environmental protection department for the concentration of NOx nitrogen oxides contained in the exhaust gas of coal-fired boilers, the industry generally adopts the technical transformation method of existing boilers for the purpose of meeting the low nitrogen emission standards. At present, the more commonly used method is to spray urea solution, ammonia water and other ammonia reducing agents into the flue of the boiler tail, so that it mixes with the flue gas to be discharged and reduces part of the NOx nitrogen oxides therein, so as to reduce the concentration of NOx in the exhaust flue gas, which has certain effects. However, since the reducing ability of the reducing agent is affected by the reduction temperature, boiler type and catalyst effect, the effect that can be produced is uncertain, and the investment and operation cost is also high. Therefore, from the perspective of economy, practicality and boiler low nitrogen emission standards, it is not ideal. With the development of boiler combustion technology in recent years, some furnace low nitrogen combustion technologies have been introduced, which can directly spray reducing agents into the high temperature zone of boiler combustion, so that the generation of NOx can be suppressed during the fuel combustion process and/or the NOx generated during the combustion process can be reduced, and the NOx content in the flue gas can be controlled from the source. Theoretically feasible, it has been generally recognized by the industry. However, how to realize it in practice still faces a series of problems that need to be studied and solved urgently, especially the spray gun for spraying reducing agent. The existing traditional spray gun with simple structure, single function and poor wear resistance and heat resistance is obviously not competent. What's more, the low-nitrogen combustion technology in the furnace currently under research must be used with a variety of reducing agents and coordinated to achieve better results. Therefore, the working applicability of the reducing agent spray gun has become a major problem that troubles the industry. In order to make the low-nitrogen combustion technology in the furnace that suppresses the generation of NOx from the source and/or reduces the NOx generated in the combustion process play its due role in the transformation of boiler low-nitrogen emission compliance, it is necessary to develop a new type of composite spray device that is compatible with it, which is both high temperature resistant and wear resistant, reliable in operation and has a long service life, is easy to set up, can select nozzles as needed, and coordinates the spraying of more than two kinds of reducing agents, so as to meet the use requirements of various boilers for low-nitrogen emission compliance transformation, and provide a basic guarantee for the efficient implementation of low-nitrogen combustion technology that suppresses and/or reduces NOx in the furnace in the transformation of boiler low-nitrogen emission.

Summary of the invention

The purpose of the present invention is to overcome the technical difficulty of the reductant injection device being unsuitable in the current low nitrogen emission transformation on boilers, and to provide an injection device which is both temperature-resistant and wear-resistant, reliable in operation, easy to install, and capable of simultaneously injecting multiple reductants.

The composite laminated high-speed reducing agent injection device of the present invention mainly comprises a housing, a reducing agent nozzle, and a reducing agent channel served by the inner cavity of the housing, and is characterized in that it also comprises a laminated composite nozzle, a swing driving mechanism and a flexible sealing strip, wherein:

The shell is made of high temperature resistant and wear resistant metal material, and the main body is in the shape of a square cylinder, including an intermediate cylinder, a flange plate arranged on the cylinder mouth at the rear end of the intermediate cylinder, and a cylinder mouth edge at the front end of the intermediate cylinder;

The reducing agent nozzles include a reducing agent A nozzle and a reducing agent B nozzle;

The reducing agent channel includes a reducing agent A channel and a reducing agent B channel;

The laminated composite nozzle comprises an upper composite nozzle and a lower composite nozzle which are stacked on each other, and an interconnected limiting shaft arranged between the upper composite nozzle and the lower composite nozzle;

The upper composite nozzle and the lower composite nozzle are integrally cast from a high temperature resistant and wear resistant metal material, resistant to high temperature corrosion and wear, and the main body is in the shape of a long trapezoid, including a top surface, an outer side surface, an inner side surface and an inner trapezoidal convergent working surface, the top surface is centrally provided with a nozzle of the reducing agent A and several nozzles of the reducing agent B are symmetrically evenly arranged on both sides of the nozzle of the reducing agent A, the bottom end of the outer side surface is extended with a straight docking strip, and the bottom end of the inner side surface is provided with an outwardly bent docking strip;

The swing drive mechanism is provided between the interconnected limit shaft and the drive motor and is composed of a connecting rod crankshaft assembly made of a high temperature resistant metal material;

The flexible sealing strip is made of high temperature resistant plastic material;

The channel of the reducing agent B is filled by the cylindrical cavity of the shell;

The channel of the reducing agent A is arranged in the channel of the reducing agent B, and the main body is branched, consisting of a main supply channel connected to the supply source, a sub-supply channel A arranged between the main supply channel and the nozzle of the upper reducing agent A, and a sub-supply channel B arranged between the main supply channel and the nozzle of the lower reducing agent A;

The middle body of the interconnected limiting shaft is fixedly welded on the outwardly bent butt joint strips on the inner side surfaces of the upper composite nozzle and the lower composite nozzle to form a laminated composite nozzle as a whole, the left and right outwardly extending end shafts of the interconnected limiting shaft are fixedly mounted on the front end barrel mouth edge of the intermediate cylinder, one end of the connecting rod crankshaft assembly is fixedly mounted on the outwardly extending end of the interconnected limiting shaft, the flexible sealing strip is fixedly mounted between the front end barrel mouth edge of the intermediate cylinder and the straight butt joint strip on the outer side surface of the laminated composite nozzle, and the sub-supply agent channel A and the sub-supply agent channel B are respectively connected to the nozzle of the upper reducing agent A and the tail end of the nozzle of the lower reducing agent A;

When working, the laminated composite nozzle as a whole is limited by the interconnected limiting shafts fixedly mounted on the edge of the front end barrel mouth by the left and right extended end shafts, and is movably installed on the front end barrel mouth of the intermediate barrel body. It can be deflected and swung within a range of 30° up and down along with the interconnected limiting shafts under the control of the swing drive mechanism. The reducing agent A and the reducing agent B are fed into the respective channels, and after passing through the internal trapezoidal convergent working surface, a high-speed airflow is formed at the nozzle and sprayed into the boiler combustion zone, and participates in low-nitrogen combustion with the function of suppressing the generation of NOx and/or reducing the NOx generated during the combustion process in an environment with low oxygen content. At the same time, the airflow of the reducing agent B sprayed from the nozzle of the reducing agent B is located around the airflow of the reducing agent A and diffused and sprayed outward, which can further optimize the flow field, reduce local high temperature, reduce the generation of thermal NOx, and further reduce the NOx concentration in the flue gas; in addition, the high-speed airflow of the reducing agent B formed around the nozzle of the reducing agent A can also serve as an isolation protective layer to avoid slagging at the nozzle and oxidation of the sprayed reducing agent A, thereby ensuring the working reliability, normal working life of the composite reduction nozzle and stable low-nitrogen combustion that meets the standards of the boiler.

The composite laminated high-speed reducing agent injection device of the present invention based on the above conception has a laminated composite nozzle that is suitable for installation on the furnace wall of the high-temperature combustion zone of the boiler and can simultaneously inject multiple reducing agents, a reducing agent channel and a reducing agent nozzle are reasonably arranged, and a swing driving mechanism that is beneficial to the divergence and injection of the reducing agent into the furnace is provided. The injected airflow is beneficial to optimizing the flow field and reducing the local high temperature, thereby suppressing the generation of thermal NOx, and the airflow ejected from the nozzle of the reducing agent B can form an isolation protection layer around the nozzle of the reducing agent A and the ejected airflow when it reaches 80-100m/s, so that the reducing agent A ejected from the nozzle of the original agent A is protected from oxidation and the denitration efficiency of the composite reducing agent is improved. The main components of the injection device are integrally cast from high-temperature resistant and wear-resistant materials, which can meet the requirements of safe and reliable operation when installed on the furnace wall of the high-temperature combustion part of the furnace and the use of low-nitrogen combustion technology in the furnace. In specific applications, the reducing agent A nozzle on the nozzle can work relatively independently or in coordination with the reducing agent B nozzle, and can be put into use according to the needs of different boilers; reducing agent A generally adopts special reducing agents such as urea solution, ammonia water, ammonia gas, etc., and the reducing agent B generally adopts fuel-type reducing agents, such as natural gas, coal-based fuel pyrolysis gas, blast furnace gas, coke oven gas, associated mine gas, etc., which can be flexibly allocated according to on-site conditions and can be applied to a variety of furnace types. When used in small industrial boilers such as chain furnaces and D-type furnaces, a hedging arrangement can be adopted. When used in power boilers such as four-corner cut-circle boilers, a four-corner arrangement can be adopted. And it is not limited by the type of boiler fuel. The present invention provides a reliable technical guarantee for the implementation of the in-furnace low-nitrogen combustion technology that can suppress the generation of NOx and/or reduce the NOx generated during the combustion process. The technical solution of the present invention is simple in structure and scientific and reasonable, safe and reliable in operation and has a long effective working life. It can simultaneously spray a variety of reducing agents and meet the use requirements of low-nitrogen standard-reaching modifications of different furnace types. It effectively solves the technical problem of the inapplicability of the reducing agent injection device currently encountered in the low-nitrogen emission standard-reaching modification of boilers. It is indeed a major innovation in this technical field and has strong practicality and valuable market application prospects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the basic structure of an embodiment of the present invention;

Fig. 2 is a cross-sectional view taken along line A-A of Fig. 1;

FIG. 3 is a schematic diagram of a three-dimensional structure of an embodiment of the present invention.

In the figure:

1. Shell 11. Middle cylinder 12. Flange 13. Front end cylinder edge 2. Reductant nozzle

21. Nozzle of reducing agent A 22. Nozzle of reducing agent B 3. Reducing agent channel

31. Channel of original agent A 311. Total agent supply channel 312. Sub-agent supply channel A

313. Supply agent channel B 32. Reducing agent B channel 4. Laminated composite nozzle

41. Upper composite nozzle 42. Lower composite nozzle 43. Interconnection limit axis

431. Left and right extended ends 44. Top surface 45. Outer surface 451. Straight butt joint strip

46. Inner side surface 461. Outward bending butt joint strip 47. Trapezoidal convergent working surface

5. Swing drive mechanism 51. Connecting rod crankshaft assembly 6. Flexible sealing strip

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and typical embodiments.

In FIG. 1 , FIG. 2 and FIG. 3 , the composite laminated reducing agent high-speed injection device of the present invention mainly comprises a housing 1, a reducing agent nozzle 2, and a reducing agent channel 3 served by the inner cavity of the housing 1, and is characterized in that it also comprises a laminated composite nozzle 4, a swing driving mechanism 5 and a flexible sealing strip 6, wherein:

The shell 1 is made of high temperature resistant and wear resistant metal material, and the main body is in the shape of a square cylinder, including an intermediate cylinder 11, an outer convex flange 12 arranged on the rear end of the intermediate cylinder 11, and a front end edge 13 of the intermediate cylinder 11;

The reducing agent nozzle 2 includes a nozzle 21 for reducing agent A and a nozzle 22 for reducing agent B;

The reducing agent channel 3 includes a reducing agent A channel 31 and a reducing agent B channel 32;

The laminated composite nozzle 4 comprises an upper composite nozzle 41 and a lower composite nozzle 42 which are stacked on each other, and an interconnected limiting shaft 43 arranged between the upper composite nozzle 41 and the lower composite nozzle 42;

The upper composite nozzle 41 and the lower composite nozzle 42 are integrally cast from a high temperature resistant and wear resistant metal material, resistant to high temperature corrosion and wear, and the main body is in the shape of a long trapezoid, including a top surface 44, an outer side surface 45, an inner side surface 46 and an inner trapezoidal convergent working surface 47, the top surface 44 is centrally provided with the nozzle 21 of the reducing agent A and a plurality of nozzles 22 of the reducing agent B symmetrically and evenly arranged on both sides of the nozzle 21 of the reducing agent A, the bottom end of the outer side surface 45 is extended with a straight docking strip 451, and the bottom end of the inner side surface 46 is provided with an outwardly bent docking strip 461;

The swing drive mechanism 5 is provided between the interconnected limit shaft 43 and the drive motor and is composed of a connecting rod crankshaft assembly 51 made of a high temperature resistant metal material;

The flexible sealing strip 6 is made of high temperature resistant plastic material;

The channel 32 of the reducing agent B is filled by the cylindrical cavity of the housing 1;

The channel 31 of the reducing agent A is arranged in the channel 32 of the reducing agent B, and the main body is branched, consisting of a main supply channel 311 connected to the supply source, a sub-supply channel A 312 arranged between the main supply channel 311 and the nozzle 21 of the upper reducing agent A, and a sub-supply channel B 313 arranged between the main supply channel 311 and the nozzle 21 of the lower reducing agent A;

The middle body of the interconnected limiting shaft 43 is fixedly welded on the outwardly bent docking strip 461 of the inner side surface 46 of the upper composite nozzle 41 and the lower composite nozzle 42 to form a laminated composite nozzle as a whole. The left and right extended ends 431 of the interconnected limiting shaft 43 are fixedly mounted on the front end barrel mouth edge 13 of the intermediate cylinder 11. One end of the connecting rod crankshaft assembly 51 is fixedly mounted on the extended end 431 of the interconnected limiting shaft 43. The flexible sealing strip 6 is fixedly mounted between the front end barrel mouth edge 13 of the intermediate cylinder 11 and the straight docking strip 451 of the outer side surface 45 of the laminated composite nozzle 4. The sub-supply agent channel A312 and the sub-supply agent channel B313 are respectively connected to the tail ends of the nozzle 21 of the upper reducing agent A and the nozzle 21 of the lower reducing agent A.

When working, the laminated composite nozzle 4 is limited by the interconnected limiting shaft 43 fixedly mounted on the front end barrel edge 13 by the left and right extended ends 431, and is movably installed on the front end barrel mouth of the intermediate cylinder 11. It can be deflected and swung within a range of 30° up and down along with the interconnected limiting shaft 43 under the control of the swing drive mechanism 5. The reducing agent A and the reducing agent B are fed into the respective channels, and after passing through the internal trapezoidal convergent working surface 47, they form a high-speed airflow at the nozzle and are sprayed into the boiler combustion zone, participating in the suppression of NOx generation and/or reduction in the combustion process in an environment with low oxygen content. In addition, the airflow of reducing agent B ejected from the nozzle 22 of reducing agent B is located around the airflow of reducing agent A and diffuses outward, which can further optimize the flow field, reduce local high temperature, reduce the generation of thermal NOx, and further reduce the NOx concentration in the flue gas; in addition, the high-speed airflow of reducing agent B formed around the nozzle 21 of reducing agent A can also serve as an isolation protective layer to avoid slagging at the nozzle and oxidation of the ejected reducing agent A, thereby ensuring the working reliability of the composite reduction nozzle, normal working life and stable low-nitrogen combustion of the boiler.

Claims (1)

1. The utility model provides a compound stromatolite formula reductant high-speed injection apparatus, mainly includes casing (1), reductant spout (2), by casing (1) inner chamber play reductant passageway (3), its characterized in that still includes stromatolite formula composite nozzle (4), swing actuating mechanism (5) and flexible sealing strip (6), wherein:

The shell (1) is made of high-temperature-resistant and wear-resistant metal materials, and the main body is square and cylindrical and comprises a middle cylinder body (11), an outer convex flange plate (12) arranged on a cylinder opening at the tail end of the middle cylinder body (11) and a cylinder opening edge (13) at the front end of the middle cylinder body (11);

The reducing agent nozzle (2) comprises a nozzle (21) of the reducing agent A and a nozzle (22) of the reducing agent B;

The reducing agent channel (3) comprises a channel (31) of the reducing agent A and a channel (32) of the reducing agent B;

the laminated composite nozzle (4) comprises an upper composite nozzle (41), a lower composite nozzle (42) and an interconnection limiting shaft (43) which are mutually overlapped, wherein the interconnection limiting shaft is arranged between the upper composite nozzle (41) and the lower composite nozzle (42);

The upper layer composite nozzle (41) and the lower layer composite nozzle (42) are formed by integrally casting high-temperature-resistant and wear-resistant metal materials, the main body is in a long trapezoid shape and comprises a top end surface (44), an outer side surface (45), an inner side surface (46) and an inner trapezoid convergent working surface (47), a nozzle (21) of a reducing agent A and a plurality of nozzles (22) of a reducing agent B, which are symmetrically and uniformly distributed on two sides of the nozzle (21) of the reducing agent A, are arranged on the top end surface (44) in a centering manner, straight butt joint strips (451) are arranged at the bottom end of the outer side surface (45) in an extending manner, and outwards bent butt joint strips (461) are arranged at the bottom end of the inner side surface (46);

The swing driving mechanism (5) is used by a connecting rod crankshaft assembly (51) which is arranged between the interconnection limiting shaft (43) and the driving motor and is made of high-temperature resistant metal materials;

the flexible sealing strip (6) is made of high-temperature-resistant plastic materials;

The channel (32) of the reducing agent B is filled by the cylinder cavity of the shell (1);

The channel (31) of the reducing agent A is arranged in the channel (32) of the reducing agent B, the main body is branched, and the reducing agent B consists of a total supply channel (311) communicated with a supply source, a sub-supply channel A (312) arranged between the total supply channel (311) and the nozzle (21) of the upper reducing agent A and a sub-supply channel B (313) arranged between the total supply channel (311) and the nozzle (21) of the lower reducing agent A;

The middle main body of the interconnecting limiting shaft (43) is fixedly welded on the inner side surfaces (46) of the upper layer composite nozzle (41) and the lower layer composite nozzle (42) to form a laminated composite nozzle whole, the left and right overhanging ends (431) of the interconnecting limiting shaft (43) are fixedly arranged on the front end barrel opening edge (13) of the middle barrel (11) in an axle manner, one end of the connecting rod crankshaft assembly (51) is fixedly arranged on the overhanging end (431) of the interconnecting limiting shaft (43), the flexible sealing strip (6) is fixedly arranged between the front end barrel opening edge (13) of the middle barrel (11) and the straight butt joint strip (451) of the outer side surface (45) of the laminated composite nozzle (4), and the agent distributing and supplying channel A (312) and the agent distributing and supplying channel B (313) are respectively connected with the tail ends of the spray opening (21) of the upper layer reducing agent A and the spray opening (21) of the lower layer reducing agent A in a corresponding manner;

When the combined nozzle works, the whole combined nozzle (4) is limited by an interconnection limiting shaft (43) which is fixedly arranged on the edge (13) of the front end nozzle through a left extending end and a right extending end, is movably arranged on the front end nozzle of the middle cylinder (11), can deflect and swing along with the interconnection limiting shaft (43) within the range of up and down 30 degrees under the control of a swinging driving mechanism (5), and the reducing agent A and the reducing agent B are sent into the combustion area of the boiler through respective channels and form high-speed airflow at the nozzle after passing through an inner trapezoid convergent working surface (47), participate in low-nitrogen combustion with the function of inhibiting the generation amount of NOx and/or reducing NOx generated in the combustion process in the environment with lower oxygen content, and simultaneously, the airflow of the reducing agent B sprayed out from the nozzle (22) of the reducing agent B is positioned around the airflow of the reducing agent A for outward diffusion and spraying, so that the flow field can be further optimized, the local high temperature can be reduced, the generation of thermal NOx can be reduced, and the concentration of NOx in the flue gas can be further reduced; in addition, the high-speed air flow of the reducing agent B formed around the nozzle (21) of the reducing agent A can also play a role of an isolating protective layer for avoiding slag bonding of the nozzle and oxidation of the sprayed reducing agent A, so that the working reliability, the normal working life of the composite reducing nozzle and stable low-nitrogen standard combustion of a boiler are ensured;

When the device is specifically applied, the nozzle of the reducing agent A (21) on the nozzle can work or work cooperatively with the nozzle of the reducing agent B (22) relatively and independently, the device is used according to different boiler requirements, flexible allocation is carried out according to site conditions, the device can be applied to various boiler types, a hedging arrangement mode can be adopted when the device is used for a small industrial boiler such as a chain boiler or a D-type boiler, a four-corner arrangement mode can be adopted when the device is used for a power boiler such as a four-corner tangential power boiler, the device is not limited by the type of boiler fuel, and the device can be used for simultaneously injecting various reducing agents and meeting the use requirements of low-nitrogen standard reconstruction of different boiler types, so that the technical problem that the reducing agent injection device is not applicable to the low-nitrogen emission standard reconstruction on the boiler at present is solved.