CN214664546U

CN214664546U - Direct-fired heating device for denitration system

Info

Publication number: CN214664546U
Application number: CN202120939369.4U
Authority: CN
Inventors: 耿明山; 任乐; 芦良; 向继涛
Original assignee: MCC Capital Engineering and Research Incorporation Ltd
Current assignee: MCC Capital Engineering and Research Incorporation Ltd
Priority date: 2021-04-30
Filing date: 2021-04-30
Publication date: 2021-11-09
Anticipated expiration: 2031-04-30

Abstract

The utility model relates to a direct-fired heating device for a denitration system, which comprises a plurality of flame burners, wherein each flame burner is used for directly heating flue gas; the plurality of flame burners form at least two burner groups; the flame stream central line of each flame burner of each burner group is tangent to an imaginary tangent circle, and the cutting directions of two adjacent burner groups are arranged oppositely; the flame spraying direction of each flame burner is opposite to the smoke stream direction, and the flame spraying length is adjustably arranged; the central axis of each flame burner is arranged at a first adjustable included angle with the horizontal direction, and the central axis of each flame burner is arranged at a second adjustable included angle with the vertical direction. The utility model discloses directly for flue gas intensification, make the flue gas temperature reach the temperature range of catalyst ideal denitration reaction, realize anticipated denitration reaction, reach ultralow emission requirement, improve equipment operation economic benefits.

Description

Direct-fired heating device for denitration system

Technical Field

The utility model relates to a flue gas denitration technical field especially relates to a direct combustion formula heating device for deNOx systems.

Background

The treatment of air pollution is an important component of environmental treatment, and people increasingly pay more attention to environmental problems and atmospheric environmental protection problems along with the development of industry and the improvement of living standard.

Nitrogen oxides (NOx) are a major class of atmospheric pollutants and are one of the major contributors to the formation of acid rain, photochemical smog, and PM2.5 pollution. At present, the industrial source NOx emission in China accounts for more than 70% of the total NOx emission amount, and the technology for controlling the emission of NOx in industrial flue gas mainly comprises a combustion control technology and a post-combustion control technology. The combustion control techniques include low nitrogen combustion techniques, reburning techniques, and flue gas recirculation techniques. Among the post-combustion control technologies, Selective Catalytic Reduction (SCR), selective non-catalytic reduction (SNCR), and SCR-SNCR hybrid technologies are the main technologies. Selective catalytic reduction is the most effective NOx post-control technology from both economic and technical efficiency points of view.

A large amount of SO is generated in the process of burning coal₂And NOx and other atmospheric pollutants cause serious atmospheric pollution and economic loss. Pollutants in flue gas discharged by industries such as thermal power, steel and the like are various, and strict requirements are provided for NOx emission. The denitration aims to remove Nitric Oxide (NO) and nitrogen dioxide (NO)₂)。

The proportion of Nitric Oxide (NO) in the flue gas is very high, often more than 90%, in nitrogen oxide (NOx). Nitric oxide is a pollutant gas, and after nitric oxide is directly discharged into the atmosphere, nitric oxide easily pollutes the atmosphere, soil and water sources, so when a factory discharges flue gas, particularly when the discharged flue gas contains nitric oxide, denitration treatment needs to be carried out on the flue gas. Wherein, current flue gas denitration technique mainly has dry process and wet process two kinds, compares with wet process flue gas denitration technique, and dry process flue gas denitration technique's main advantage is: low basic investment, simple equipment and process, high NOx removing efficiency, no wastewater and waste treatment and difficult secondary pollution.

The completion of the SCR reaction requires the use of a catalyst. At present, the catalyst is widely applied to a medium-temperature catalyst with the operation temperature of 320-450 ℃, so the reaction temperature of catalytic reduction denitration is controlled to be 320-450 ℃. When the reaction temperature is lower than 300 ℃, a side reaction occurs on the surface of the catalyst, and ammonia reacts with sulfur trioxide and water to generate (NH)₄)₂SO₄Or NH₄SO₄Reduce the reaction with NOx, and the resultant is attached to the surface of the catalyst to block the catalyst channels and micropores and reduce the activity of the catalyst. In addition, if the reaction temperature is higher than the applicable temperature of the catalyst, the catalyst channels and micropores are deformed, thereby deactivating the catalyst. Thus ensuring the proper reaction temperature is critical to the proper operation of the selective catalyst reduction process. Low boiler loads or low atmospheric temperatures will cause the SCR inlet temperature to be lower than the catalyst use temperature. Wherein the SCR denitration needs a temperature window of 300-400 ℃, NOx is in a catalyst and NH₃Is reduced to N₂And the denitration efficiency can reach more than 90%.

Need heat the flue gas to the high efficiency that preset temperature rear can carry out the denitration process in the denitration process and stably go on, thereby often adopt to set up the heating source and rise through high-temperature gas and the even purpose of realizing the heating with the flue gas misce bene in denitration flue below the flue gas heating among the prior art, and because the general size of deNOx systems pipeline is longer, therefore the high-temperature gas who lies in mixed layer below rises the in-process and can not avoid causing calorific loss, simultaneously in high-temperature gas's the rising in-process with the flue gas mixing length in the axial long enough, but can not guarantee radially that the mixed face is enough big in footpath, therefore can not guarantee the complete of high-temperature gas and flue gas, homogeneous mixing.

In the industries of steel, metallurgy and coal chemical industry, the exhaust gas temperature of equipment such as a sintering machine is low, and in order to meet the requirements of denitration treatment or other processes in SCR equipment, the exhausted exhaust gas needs to be heated. The flue gas heating has multiple modes, for example directly add the heat exchanger, set up electric heating etc. and heat through drawing high temperature heat source, these modes lead to the running cost higher because need additionally increase the heating source.

In addition, in industrial facilities in the steel, metallurgy, and coal chemical industries, a large amount of fuel gas such as blast furnace gas, converter gas, and coke oven gas is generally generated. Therefore, in the prior art, many enterprises can use the fuel gas, an independent heating furnace is arranged outside a flue, one or more blast furnace gas or coke oven gas burners are arranged according to the power of the heating furnace, the fuel gas in the burners is combusted to generate high-temperature flue gas, and the high-temperature flue gas is sent into the flue through a branch and is mixed with original flue gas in the flue, so that the original flue gas is heated. According to the method, the heating furnace is required to be arranged outside the flue independently, so that on one hand, the investment cost is high, and on the other hand, after high-temperature flue gas generated after fuel gas is combusted is mixed with original flue gas in the flue, the total amount of the flue gas in the flue is increased rapidly, so that a flue gas system is greatly influenced, and the problem that the existing induced draft fan is insufficient in output is caused.

At present, the environment protection situation of the steel industry is getting more severe, and steel enterprises need to develop ultra-low emission reconstruction step by step. The most applied technology of the steel plant which implements low emission modification at present is to build a set of SCR denitration device and then heat flue gas by utilizing the combustion of the blast furnace gas of the steel plant, thereby meeting the requirement of denitration inlet smoke temperature.

Blast furnace gas is difficult to ignite due to low heat value, generally adopts a heat insulation ignition air duct which is independently laid with castable, firstly adopts natural gas or a light oil gun and the like to ignite, raises the temperature in the ignition air duct, then introduces the blast furnace gas to burn, finally mixes the burnt high-temperature flue gas into a denitration flue to heat the denitration flue gas. Although the heat value of blast furnace gas is low, the temperature of high-temperature flue gas generated by the blast furnace gas can reach 1200-1400 ℃ because the blast furnace gas is combusted in a heat insulation flue, and the combustion temperature can be higher and can reach 1500-1700 ℃ in the ignition process, if natural gas or an oil gun is used for ignition, while the service temperature of common refractory castable is about 1300 ℃, so that the castable of an ignition air duct is easy to fall off, and then a wind barrel steel plate is deformed at high temperature, so that the service life is shortened; if the refractory castable with better service performance, such as alumina hollow sphere castable, is expensive, the manufacturing cost is greatly increased; in addition, in the prior art, the combustion smoke temperature is reduced by using a large excess air coefficient, but in this way, the additional required air is greatly increased for heating, so that more fuel gas needs to be added, and the economy is deteriorated.

Among the prior art, there is a direct combustion formula temperature rise heating device (CN 209501296U) for deNOx systems, still there is a flue gas heating system (CN 210069874U), direct-fired furnace all adopts the mode of arranging of counterpulsation among the two, the flame combustion is regional relatively fixed, the flue gas heating region is less, can't heat to the flue of big cross-section, the regional temperature that is close to direct-fired furnace flame region is higher, the regional temperature that is close to the flue wall all around is lower, it is relatively poor at cross-section axle air current mixing effect, be unfavorable for thermal quick transfer and evenly distributed.

Therefore, the inventor provides a direct-fired heating device for a denitration system by virtue of experience and practice of related industries for many years, so as to overcome the defects in the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a direct combustion formula heating device for deNOx systems overcomes the problem that exists among the prior art, and the device directly heaies up for the flue gas, makes the flue gas temperature reach the temperature range of catalyst ideal denitration reaction, realizes anticipated denitration reaction, reaches ultralow emission requirement, improve equipment operation economic benefits.

The utility model aims at realizing the direct-fired heating device for the denitration system, which comprises a plurality of flame burners arranged on the side wall of the denitration flue, wherein each flame burner is used for directly heating the temperature-rising flue gas; the plurality of flame burners form at least two burner groups; the flame stream central line of each flame burner of each burner group is tangent to an imaginary tangent circle, and the cutting directions of the flame stream central lines of the adjacent two burner groups and the imaginary tangent circle are opposite; the flame spraying direction of each flame burner is opposite to the smoke stream direction, and the flame spraying length of each flame burner is adjustably arranged; the central axis of each flame burner is arranged at an adjustable first included angle with the horizontal direction, and the central axis of each flame burner is arranged at an adjustable second included angle with the vertical direction.

In a preferred embodiment of the present invention, the direct-fired heating apparatus for a denitration system further includes a control system.

In a preferred embodiment of the present invention, each of the flame burners includes a stable combustion flue structure, a flame injection port is disposed at a first end of the stable combustion flue structure, and a central axis of the stable combustion flue structure forms a central axis of the flame burner; the second end of the stable combustion flue structure is communicated with a combustion assisting gas cavity and a combustion gas cavity; connect on the lateral wall of surely firing flue structure and set up first revolution mechanic, first revolution mechanic is used for the drive swing surely fire flue structure in order to adjust first contained angle, the top of surely firing flue structure is connected and is set up second revolution mechanic, second revolution mechanic is used for the drive swing surely fire flue structure in order to adjust the second contained angle.

In a preferred embodiment of the present invention, the first rotating structure includes a rotating frame, a first speed reducer and a first motor, and both the first speed reducer and the first motor are electrically connected to the control system; the rotary frame is fixedly sleeved on the stable combustion flue structure, the rotary frame is hinged to a fixed support, the first speed reducer is connected to the fixed support through a first flange, the first motor is connected with the rotary frame through the first speed reducer, and the first motor can drive the rotary frame to rotate so as to adjust the first included angle.

In a preferred embodiment of the present invention, the second rotating structure includes a rotating support, a second speed reducer and a second motor, and both the second speed reducer and the second motor are electrically connected to the control system; rotatory support fixed connection in surely fires the top of flue structure, the second reduction gear pass through second flange joint in the top of rotatory support, the second motor passes through the second reduction gear with rotatory support is connected, the second motor can drive rotatory support is rotatory in order to adjust the second contained angle.

In a preferred embodiment of the present invention, a burner through hole is disposed on a side wall of the denitration flue, the stable combustion flue structure is inserted through the burner through hole, and a diameter of the burner through hole is larger than a diameter of the stable combustion flue structure; the lateral wall of the stable combustion flue structure is sleeved with a third flange, the third flange is connected with one end of a corrugated pipe, the other end of the corrugated pipe is connected with a fourth flange, the fourth flange is hermetically connected with the denitration flue lateral wall outside the burner through hole, and the third flange, the corrugated pipe and the fourth flange form a burner elastic connection sealing cover.

In a preferred embodiment of the present invention, a stable combustion central hole is axially arranged in the stable combustion flue structure, the stable combustion central hole forms a combustion mixing chamber, an igniter is arranged in the combustion mixing chamber, and the igniter is electrically connected to the control system; the combustion-supporting gas cavity is communicated with a combustion-supporting gas inlet, and the gas cavity is communicated with a gas inlet; the ejector is arranged in the gas cavity and the combustion-supporting gas cavity in a penetrating mode, the ejector and the stable combustion flue structure are coaxially arranged, the ejector is used for accelerating and injecting combustible gas in the gas cavity to the combustion mixing chamber, a necking injection channel is formed between the combustion-supporting gas cavity and the combustion mixing chamber, and the combustion-supporting gas in the combustion-supporting gas cavity is injected to the combustion mixing chamber through the injection channel.

The utility model discloses an among the preferred embodiment, surely fire flue structure and include the steady inner tube of firing and surely fire the outer tube of coaxial and radial interval setting, the closed profile setting of the concatenation of the transversal multistage circular arc of personally submitting of surely firing the inner tube, surely fire the transversal circular setting of personally submitting of outer tube, surely fire the inner tube with surely fire the annular space of constituteing between the outer tube, surely fire the intussuseption of annular space intussuseption and fire-resistant pouring unit.

In a preferred embodiment of the present invention, a flame detector and a temperature detector are disposed in the combustion mixing chamber, and both the flame detector and the temperature detector are electrically connected to the control system; the flame detector is used for detecting the flame combustion condition in the combustion mixing chamber, and the temperature detector is used for detecting the temperature in the combustion mixing chamber.

In a preferred embodiment of the present invention, the injector includes a straight pipe section, a contraction section, a throat section, an expansion section, and a rectification section, the straight pipe section is located in the gas chamber, and the contraction section, the throat section, the expansion section, and the rectification section are located in the combustion-supporting gas chamber; the first end of straight tube section sets up the inlet pipe mouth, the second end intercommunication of straight tube section the first end of convergent section, the diameter of convergent section is the convergent setting from one end to the second end, the second end intercommunication of convergent section the first end of larynx section, the second end intercommunication of larynx section the first end of expansion section, the diameter of expansion section is the divergent setting from one end to the second end, the second end intercommunication of expansion section the first end of rectifying section, the second end of rectifying section sets up the outlet pipe mouth.

The utility model discloses an in a preferred embodiment, the rectification section includes the rectification inner tube and the rectification outer tube that coaxial and radial interval set up, the closed profile setting of multistage circular arc concatenation is personally submitted in the transversal of rectification inner tube, the transversal circular setting of personally submitting of rectification outer tube, constitute rectification annular space between rectification inner tube and the rectification outer tube, the intussuseption of rectification annular space is filled fire-resistant pouring material unit.

In a preferred embodiment of the present invention, the first included angle ranges from 10 ° to 50 °, and the second included angle ranges from 15 ° to 85 °.

The utility model discloses an among the preferred embodiment, denitration flue is the rectangle flue and is vertical setting, wears to establish 2 on two relative lateral walls of denitration flue combustor group, each combustor group includes 4 the flame burner, each the flame burner constitutes eight octagonal bitangent circle burning structure.

From top to bottom, the utility model provides a direct combustion formula heating device for deNOx systems has following beneficial effect:

(1) in the direct-fired heating device for the denitration system, a plurality of flame burners are arranged in the denitration flue in a grouping manner, and the flue gas is directly heated by utilizing the flame combustion heat of the flame burners, so that the utilization efficiency of heat is improved, and the heat loss is reduced;

(2) a plurality of flame burners in the denitration flue are grouped to form an independent cyclone area, so that the dynamic cyclone effect of the flue gas is realized, the turbulent flow of the flue gas is promoted, the heat exchange between the flue gas and high-temperature flame is promoted, the length of a heat exchange area in the flue is shortened, and the homogenization of the temperature is realized; the high-efficiency combustion of combustible gas and combustion-supporting air is carried out in the flame burners, and the jet swirl action of a plurality of flame burners is utilized to promote the rapid mixing and heat exchange of high-temperature gas and flue gas;

(3) the flame spraying direction of the flame burner is opposite to the flue gas stream direction, so that the rapid and efficient heat exchange between the flue gas and the high-temperature flame is promoted, the time required by the heat exchange is shortened, the length of a flue required by the uniform temperature of the flue gas is reduced, and the homogenization of the temperature in the flue is promoted;

(4) the included angle between the central axis of each flame burner and the horizontal direction and the vertical direction can be adjusted, the function of dynamically adjusting the flame jet flow in the horizontal direction and the vertical direction is realized, the requirements of dynamic heating in different areas are met, and the dynamic adjustment of the size and the strength of a rotational flow area is realized;

(5) the flame burner adopts an ejector jet technology, so that the load of a system fan is reduced, the resistance loss of a flue is reduced, and the running stability of equipment is improved; the cross sections of the stable combustion inner tube of the stable combustion flue structure and the rectifying section of the ejector are spliced by a plurality of sections of arcs, so that the contact area of combustible gas and combustion-supporting gas is increased, the combustion stability is kept, the injected flame has good gathering effect, the premature divergence and attenuation of the flame are avoided, the flame injected by a plurality of flame burners has high kinetic energy, the flue gas of the flue is subjected to efficient turbulent stirring, and the heat exchange is promoted; meanwhile, the multi-arc-shaped circular cross section structure can reduce the local oxygen content of combustible gas combustion, reduce the local high temperature of a flame burner, avoid the generation of NOx and realize low-nitrogen combustion;

(6) the utility model discloses a direct combustion formula heating device for deNOx systems directly heats up for the flue gas, makes the flue gas temperature reach the temperature range of catalyst ideal denitration reaction, realizes anticipated denitration reaction, reaches ultralow emission requirement, improve equipment operation economic benefits.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

FIG. 1: do the utility model discloses a direct combustion formula heating device's installation schematic diagram for deNOx systems.

FIG. 2: is a cross-sectional view a-a in fig. 1.

FIG. 3: is a front view of the outer structure of the flame burner of the utility model.

FIG. 4: is a side view of the outer structure of the flame burner of the utility model.

FIG. 5: do the utility model discloses a flame burner and denitration flue lateral wall's connection schematic diagram.

FIG. 6: is a cross-sectional view of the flame burner of the utility model.

FIG. 7: which is a view along direction B in fig. 6.

FIG. 8: do the utility model discloses an ejector's schematic diagram.

FIG. 9: is a view along direction C in fig. 8.

In the figure:

100. a direct-fired heating device for the denitration system;

1. a flame burner;

10. a hypothetical tangent circle; 11. a stable combustion flue structure; 111. stably burning the central hole; 112. stably burning the inner pipe; 113. stably burning the outer pipe; 12. a flame jet orifice; 13. a third flange; 14. a bellows; 15. a fourth flange; 16. an igniter; 17. a flame detector; 18. a temperature detector;

2. a combustion-supporting gas chamber; 21. a combustion-supporting gas inlet;

3. a gas chamber; 31. a gas inlet;

4. a first rotating structure;

41. a rotating frame; 42. a first decelerator; 43. a first motor; 44. fixing a bracket; 45. a first flange;

5. a second rotating structure;

51. rotating the support; 52. a second decelerator; 53. a second motor; 54. a second flange;

6. an ejector;

61. a straight pipe section; 62. a contraction section; 63. a throat section; 64. an expansion section; 65. a rectifying section; 651. a rectification inner pipe; 652. rectifying the outer pipe; 66. an air inlet pipe orifice; 67. an air outlet pipe orifice;

7. a refractory pouring unit;

9. a denitration flue;

91. a front side wall; 92. a rear sidewall; 93. the burner is through the hole.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

The specific embodiments of the present invention described herein are for the purpose of explanation only and should not be construed as limiting the invention in any way. Given the teachings of the present invention, the skilled person can conceive of any possible variants based on the invention, which should all be considered as belonging to the scope of the invention. It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, mechanical or electrical connections, communications between two elements, direct connections, indirect connections through intermediaries, and the like. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1 to 9, the present invention provides a direct-fired heating device 100 for a denitration system, comprising a plurality of flame burners 1 arranged on the side wall of a denitration flue 9, each flame burner 1 being used for directly heating flue gas; the plurality of flame burners 1 form at least 2 burner groups, and the number of the burner groups is even; the flame stream central line of each flame burner of each burner group is tangent to an imaginary tangent circle, and the cutting directions of the flame stream central lines of two adjacent burner groups and the imaginary tangent circle 10 are opposite; the flame spraying direction of each flame burner 1 and the smoke stream direction are oppositely arranged, the flame spraying length L of each flame burner 1 is adjustably arranged, and the flame length of the flame burner can be adjusted by adjusting the flow and the proportion of combustible gas and combustion-supporting gas of the flame burner; the central axis of each flame burner 1 and the horizontal direction form an adjustable first included angle alpha, and the central axis of each flame burner 1 and the vertical direction form an adjustable second included angle; the direct combustion heating apparatus 100 for a denitration system further includes a control system (not shown in the drawings).

The mode of directly heating the flue gas in the flue can save the flue gas quantity, and can also greatly save the engineering cost and the land used in the factory. The mode of direct heating flue gas in current flue has certain technical problem: negative pressure in the flue is large, and the combustor is not easy to stably burn; the temperature rise of the flue gas directly contacted with the flame is high, and the temperature rise of the flue gas far away from the flame is low, so that the temperature of the flue gas is not uniform; the flame is easily extinguished due to the washing of the flame by the smoke; the ignition point of combustible gas is high, the content of inert gas is high, and the combustible gas is not easy to stably burn. And the utility model discloses a direct combustion formula heating device for deNOx systems can effectively solve above problem.

In the denitration flue of the denitration system, before direct combustion heating, the flue gas flowing direction is from top to bottom, and the central line of the flame stream of the middle flame burner of the utility model faces the flue gas stream direction and is arranged opposite to the flue gas stream direction (from bottom to top and in an inclined state); as shown in figure 1, the flame burner 1 is arranged in an upward inclined manner, and the flame and the flue gas before heating flow in opposite directions, so that the turbulence degree of heat exchange between the high-temperature flue gas and the original flue gas is increased, the time required by heat exchange is shortened, the contact area between the flame and the flue gas is increased, the time for heat exchange between the high-temperature flame and the flue gas is increased, and the uniformity of the temperature of the flue gas is facilitated.

The cutting-in directions of the flame stream central lines of the two adjacent burner groups and the imaginary tangent circle are arranged oppositely, namely the cutting-in directions of the flame stream central lines of the two adjacent burner groups and the imaginary tangent circle adopt opposite rotational flow modes, the impact influence of the two groups of rotational flow flame burners is eliminated, and the stable operation of rotational flow is realized. The number of the burner groups is even number, so that the stable operation of the heating device is ensured.

The flame jet length of each flame burner 1 can be adjusted, the diameters of imaginary tangent circles tangent to the flame stream central lines of each flame burner of each burner group are different, the height positions of the imaginary tangent circles are different, different swirl mixing area control can be realized under different flue gas flow conditions, the position of a flame high-temperature area in a flue can be adjusted, and the dynamic adjustment of flue gas mixing is realized.

In the denitration system, a temperature detection device is arranged at the downstream of an SCR denitration catalyst to detect the actual temperature of the flue gas subjected to denitration reaction, if the temperature is within the process requirement range, the flow and the proportion of a flame burner do not need to be adjusted, and if the temperature is lower than the process requirement, the combustion heat productivity of the flame burner is improved, so that the further improvement of the temperature of the flue gas is realized; if the temperature is higher than the process requirement, the combustion heat productivity of the flame burner is reduced, and the further reduction of the flue gas temperature is realized; the combustion heat released by the flame burner is fed back and controlled through the temperature detection device, and the temperature of the flue gas is controlled within the optimal temperature range of the denitration reaction.

In the direct-fired heating device for the denitration system, a plurality of flame burners are arranged in the denitration flue in a grouping manner, and the flue gas is directly heated by utilizing the flame combustion heat of the flame burners, so that the utilization efficiency of heat is improved, and the heat loss is reduced; a plurality of flame burners in the denitration flue are grouped to form an independent cyclone area, so that the dynamic cyclone effect of the flue gas is realized, the turbulent flow of the flue gas is promoted, the heat exchange between the flue gas and high-temperature flame is promoted, the length of a heat exchange area in the flue is shortened, and the homogenization of the temperature is realized; the flame spraying direction of the flame burner is opposite to the flue gas stream direction, so that the rapid and efficient heat exchange between the flue gas and the high-temperature flame is promoted, the time required by the heat exchange is shortened, the length of a flue required by the uniform temperature of the flue gas is reduced, and the homogenization of the temperature in the flue is promoted; the included angle between the central axis of each flame burner and the horizontal direction and the vertical direction can be adjusted, the function of dynamically adjusting the flame jet flow in the horizontal direction and the vertical direction is realized, the requirements of dynamic heating in different areas are met, and the dynamic adjustment of the size and the strength of a rotational flow area is realized; the utility model discloses a direct combustion formula heating device for deNOx systems directly heats up for the flue gas, makes the flue gas temperature reach the temperature range of catalyst ideal denitration reaction, realizes anticipated denitration reaction, reaches ultralow emission requirement, improve equipment operation economic benefits.

Further, the range of the first included angle alpha is 10-50 degrees, and the preferred range is 15-30 degrees; the second included angle is in the range of 15-85 degrees, and the preferable range is 30-65 degrees.

Further, as shown in fig. 2, the denitration flue 9 is a rectangular flue and is vertically arranged, a central line of two opposite side walls (a front side wall 91 and a rear side wall 92) of the denitration flue 9 is an opposite center line, the flame burners are divided into 2 groups, each burner group comprises 4 flame burners 1, the flame burners are in a tangential combustion mode, gas streams of the flame burners are fed in a tangential mode, and each flame burner 1 forms an octagonal double tangential combustion structure. The central line of the flame stream sprayed by each group of flame burners is tangent to the same imaginary tangent circle (ellipse or circle), the rotating directions of the two groups of imaginary tangent circles (ellipse or circle) are opposite, one is clockwise, and the other is anticlockwise.

In practical engineering application, flame burners can be properly added on the front side wall 91 and the rear side wall 92 according to the size of the section of the denitration flue 9; flame burners can also be added on the other two side walls of the denitration flue 9.

As shown in fig. 2, in an embodiment of the present invention, the included angles (i.e. the second included angles) between the 8 flame burners and the side wall of the vertical denitration flue 9 are respectively β₁、β₂、β₃、β₄、β₅、β₆、β₇、β₈The range is 15-85 degrees, and the preferred range is 30-65 degrees.

Further, as shown in fig. 3, 4, and 6, each flame burner 1 includes a stable combustion flue structure 11, the stable combustion flue structure 11 is a cylindrical structure, a flame injection port 12 is disposed at a first end of the stable combustion flue structure 11, and a central axis of the stable combustion flue structure 11 forms a central axis of the flame burner; the second end of the stable combustion flue structure 11 is communicated with the combustion-supporting gas cavity 2 and the gas cavity 3; connect on the lateral wall of surely firing flue structure 11 and set up first revolution mechanic 4, first revolution mechanic 4 is used for driving the first contained angle alpha of steady firing flue structure 11 of swing, surely fires the top connection of flue structure 11 and sets up second revolution mechanic 5, and second revolution mechanic 5 is used for driving the second contained angle of steady firing flue structure 11 of swing.

Further, as shown in fig. 3, the first rotating structure 4 includes a rotating frame 41, a first reducer 42 and a first motor 43, and both the first reducer 42 and the first motor 43 are electrically connected to the control system; the rotating frame 41 is fixedly sleeved on the stable combustion flue structure 11, the rotating frame 41 is hinged on a fixed support 44, the first speed reducer 42 is connected on the fixed support 44 through a first flange 45, and the fixed support 44 is fixedly connected with the side wall of the denitration flue 9. The first motor 43 is connected to the rotating frame 41 through the first speed reducer 42, and the first motor 43 can drive the rotating frame 41 to rotate to adjust the first included angle α. The first motor 43 can realize the accurate control of the number of the rotation turns of the motor through an encoder (in the prior art), and can realize the resetting of the initial position of the stable combustion flue by meeting the accurate setting and control of the rotation angle of the flame burner.

Further, as shown in fig. 4, the second rotating structure 5 includes a rotating support 51, a second speed reducer 52 and a second motor 53, and both the second speed reducer 52 and the second motor 53 are electrically connected to the control system; the rotating support 51 is fixedly connected to the top of the stable combustion flue structure 11, the second speed reducer 52 is connected to the top of the rotating support 51 through the second flange 54, the second motor 53 is connected to the rotating support 51 through the second speed reducer 52, and the second motor 53 can drive the rotating support 51 to rotate so as to adjust the second included angle. The rotating support 51 and the combustion stabilizing flue structure 11 are connected by welding, the rotating support 51 is connected with an output shaft of the second speed reducer 52, the second motor 53 is used for driving the rotating support 51 to rotate, and the rotation of the combustion stabilizing flue structure 11 in the horizontal plane is driven by the rotation of the rotating support 51. The second motor 53 can realize the accurate control of the number of rotation turns of the motor through an encoder (in the prior art), and can realize the resetting of the initial position of the stable combustion flue by meeting the accurate setting and control of the rotation angle of the flame burner.

The first included angle alpha is adjusted by the first rotating structure 4, and the second included angle is adjusted by the second rotating structure 5, so that the dynamic adjustment of flame jet flow of the flame burner can be realized. By the number of rotations of the first motor 43 and the initial position of the rotating frame 41, it is possible to realize accurate setting and control of the first angle α (the angle between the central axis of each flame burner and the horizontal direction is controlled by controlling the rotation angle of the rotating frame 41), and at the same time, it is possible to realize resetting of the initial position of the rotating frame 41 by the control system. Through the number of rotations of second motor 53 and the initial position of surely firing flue structure 11, can realize the accurate settlement and the control of second contained angle (surely firing flue structure 11 and vertical direction's contained angle), can realize surely firing the reset of flue structure 11 initial position simultaneously through control system.

Further, as shown in fig. 5, a burner through hole 93 is formed in the side wall of the denitration flue, the stable combustion flue structure 11 penetrates through the burner through hole 93, and the diameter of the burner through hole 93 is greater than that of the stable combustion flue structure 11, in a specific embodiment of the present invention, the distance between the inner wall of the burner through hole 93 and the outer wall of the stable combustion flue structure 11 is not less than 300mm (i.e., the difference between the two radii is not less than 300 mm); the space between the inner wall of the burner through hole 93 and the outer wall of the stable combustion flue structure 11 can realize the rotation of the stable combustion flue structure 11 in the horizontal direction and the vertical direction, and realize the space dynamic adjustment of the jetting angles (the first included angle alpha and the second included angle) of the high-temperature flame jet of the flame burner; a third flange 13 is sleeved on the side wall of the stable combustion flue structure 11, and the third flange 13 is welded on the stable combustion flue structure 11; one end of a corrugated pipe 14 is connected to the third flange 13, the other end of the corrugated pipe 14 is connected to the fourth flange 15, in this embodiment, the length of the corrugated pipe 14 is not less than 600mm, and the distance from the outlet end of the stable combustion flue structure 11 to the inner wall of the side wall of the flue is not more than 100 mm. The fourth flange 15 is connected with the denitration flue side wall outside the combustor via hole 93 in a sealing manner, and the third flange 13, the corrugated pipe 14 and the fourth flange 15 form a combustor elastic connection sealing cover.

Further, as shown in fig. 6, a stable combustion central hole 111 is axially arranged on the stable combustion flue structure 11 in a penetrating manner, the stable combustion central hole 111 forms a combustion mixing chamber, an igniter 16 is arranged in the combustion mixing chamber, and the igniter 16 is electrically connected with the control system; the combustion-supporting gas cavity 2 is communicated with a combustion-supporting gas inlet 21, and the gas cavity 3 is communicated with a gas inlet 31; wear to establish ejector 6 in gas chamber 3 and the combustion-supporting gas chamber 2, ejector 6 with surely fire 11 coaxial settings of flue structure, ejector 6 is used for ejecting combustible gas in the gas chamber 3 to the combustion mixing chamber with higher speed, constitutes the injection passageway of necking down between combustion-supporting gas chamber 2 and the combustion mixing chamber, and the combustion-supporting gas in the combustion-supporting gas chamber 2 is penetrated to the combustion mixing chamber through injecting the passageway. The flame burner 1 adopts an ejector jet technology, so that the load of a system fan is reduced, the resistance loss of a flue is reduced, and the running stability of equipment is improved. The combustion-supporting gas inlet 21 and the fuel gas inlet 31 are connected with corresponding pipelines through flanges, flow meters and flow regulating valves are arranged on the corresponding pipelines, and the flow meters and the flow regulating valves are electrically connected with a control system. The required demand of combustible gas and combustion-supporting gas is calculated by using the detection data of a temperature detection device in the denitration system according to a control model, and flow regulation is carried out through a flow regulating valve (electric regulating valve) until the flow reaches the preset demand.

The combustion-supporting gas can pass through the flue gas behind the heat exchanger (in the denitration flue, prior art) in the pipe connection entry flue section (prior art, the entrance of denitration flue), utilize the flue gas in the former flue as combustion-supporting gas to carry out the combustion reaction of flame burner, realize the burning under combustible gas's the low oxygen concentration condition, avoid producing NOx, realize the low nitrogen burning of gas.

The combustible gas entering the flame burner can be blast furnace gas, converter gas, coke oven gas, natural gas and the like, and can also be mixed gas of the blast furnace gas, the converter gas, the coke oven gas, the natural gas and the like. The combustion-supporting gas entering the flame burner can be air, pure oxygen or raw flue gas in a flue containing certain oxygen.

Further, as shown in fig. 6 and 7, the stable combustion flue structure 11 includes a stable combustion inner tube 112 and a stable combustion outer tube 113 that are coaxially and radially arranged at intervals, the cross section of the stable combustion inner tube 112 is arranged in a closed contour formed by splicing a plurality of sections of circular arcs, and the number of the spliced circular arcs is preferably even; the cross section of the stable combustion outer pipe 113 is circular, a stable combustion annular space is formed between the stable combustion inner pipe 112 and the stable combustion outer pipe 113, and the stable combustion annular space is filled with the refractory pouring material unit 7. The cross section of the stable combustion inner tube 112 is spliced by multiple sections of circular arcs, so that the contact area of high-temperature flame and flue gas is increased, the heat exchange of the flue gas is promoted, the combustion flame is kept in a better gathering effect, the length of the flame is increased, and the premature divergence and attenuation of the flame are avoided.

Further, as shown in fig. 6, a flame detector 17 and a temperature detector 18 are arranged in the combustion mixing chamber, and both the flame detector 17 and the temperature detector 18 are electrically connected with the control system; the flame detector 17 is used for detecting the flame combustion condition in the combustion mixing chamber, if the flame is extinguished, the secondary ignition of the igniter is realized through the control system, and the stable combustion of the flame burner is realized; the temperature probe 18 is used to detect the temperature within the combustion mixture chamber.

Further, as shown in fig. 8, the ejector 6 includes a straight pipe section 61, a contraction section 62, a throat section 63, an expansion section 64, and a rectification section 65, the straight pipe section 61 is located in the fuel gas chamber 3, and the contraction section 62, the throat section 63, the expansion section 64, and the rectification section 65 are located in the fuel gas chamber 2; the first end of straight tube section 61 sets up air inlet pipe mouth 66, the first end of the second end intercommunication shrink section 62 of straight tube section 61, the diameter of shrink section 62 is the convergent setting from the first end to the second end, the first end of the second end intercommunication larynx pipeline section 63 of shrink section 62, the second end and the larynx pipeline section 63 of shrink section 62 adopt pitch arc rounding off, the first end of the second end intercommunication expansion section 64 of larynx pipeline section 63, the diameter of expansion section 64 is the flaring setting from the first end to the second end, the second end intercommunication rectifying section 65's of expansion section 64 first end, rectifying section 65's second end sets up air outlet pipe mouth 67, air outlet pipe mouth 67 is in drawing the passageway.

In a specific embodiment of the present invention, the length of the expansion section 64 is 6 to 10 times of the diameter of the throat section 63, the preferred range is 7 to 9 times, and the length of the rectification section 65 is not less than 100 mm. The distance between the air outlet pipe opening 67 of the ejector and the bottom of the combustion mixing chamber is 100-300 mm, and the optimal range is 150-250 mm.

Further, as shown in fig. 8 and 9, the rectifying section 65 includes a rectifying inner tube 651 and a rectifying outer tube 652 which are coaxially and radially arranged at an interval, the cross section of the rectifying inner tube 651 is arranged in a closed contour formed by splicing a plurality of circular arcs, the cross section of the rectifying outer tube 652 is arranged in a circular shape, a rectifying annular space is formed between the rectifying inner tube 651 and the rectifying outer tube 652, and the rectifying annular space is filled with the refractory casting unit 7.

The many arcs of rectification section 65 circle cross-section can make combustible gas break away from still can keep many arcs circle cross-section to spout forward after giving vent to anger mouth of pipe 67, many arcs circle cross-sectional shape has increased combustible gas and combustion-supporting gas's area of contact, the stability of burning has been kept simultaneously, the realization is sprayed flame simultaneously and has good effect of gathering together, avoid the too early divergence and the decay of flame, the flame of guaranteeing a plurality of flame burner injection has higher kinetic energy, carry out efficient turbulent stirring to the flue gas of flue, promote the heat exchange. Meanwhile, the multi-arc-shaped circular cross section structure can reduce the local oxygen content of combustible gas combustion, reduce the local high temperature of the flame burner, avoid the generation of NOx and realize low-nitrogen combustion.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention.

Claims

1. A direct-fired heating device for a denitration system is characterized by comprising a plurality of flame burners arranged on the side wall of a denitration flue in a penetrating manner, wherein each flame burner is used for directly heating flue gas; the plurality of flame burners form at least two burner groups; the flame stream central line of each flame burner of each burner group is tangent to an imaginary tangent circle, and the cutting directions of the flame stream central lines of the adjacent two burner groups and the imaginary tangent circle are opposite; the flame spraying direction of each flame burner is opposite to the smoke stream direction, and the flame spraying length of each flame burner is adjustably arranged; the central axis of each flame burner is arranged at an adjustable first included angle with the horizontal direction, and the central axis of each flame burner is arranged at an adjustable second included angle with the vertical direction.

2. The direct combustion heating apparatus for a denox system of claim 1, wherein the direct combustion heating apparatus for a denox system further comprises a control system.

3. The direct-fired heating apparatus for a denitration system of claim 2, wherein each of the flame burners includes a stable-combustion flue structure, a first end of the stable-combustion flue structure is provided with a flame injection port, and a central axis of the stable-combustion flue structure constitutes a central axis of the flame burner; the second end of the stable combustion flue structure is communicated with a combustion assisting gas cavity and a combustion gas cavity; connect on the lateral wall of surely firing flue structure and set up first revolution mechanic, first revolution mechanic is used for the drive swing surely fire flue structure in order to adjust first contained angle, the top of surely firing flue structure is connected and is set up second revolution mechanic, second revolution mechanic is used for the drive swing surely fire flue structure in order to adjust the second contained angle.

4. The direct combustion heating apparatus for a denitration system according to claim 3, wherein the first rotary structure comprises a rotary frame, a first speed reducer and a first electric motor, both of which are electrically connected to a control system; the rotary frame is fixedly sleeved on the stable combustion flue structure, the rotary frame is hinged to a fixed support, the first speed reducer is connected to the fixed support through a first flange, the first motor is connected with the rotary frame through the first speed reducer, and the first motor can drive the rotary frame to rotate so as to adjust the first included angle.

5. The direct combustion heating apparatus for a denitration system according to claim 4, wherein the second rotation structure comprises a rotation support, a second speed reducer and a second electric machine, both of which are electrically connected to the control system; rotatory support fixed connection in surely fires the top of flue structure, the second reduction gear pass through second flange joint in the top of rotatory support, the second motor passes through the second reduction gear with rotatory support is connected, the second motor can drive rotatory support is rotatory in order to adjust the second contained angle.

6. The direct-fired heating device for the denitration system of claim 3, wherein a burner through hole is provided on a side wall of the denitration flue, the combustion stabilizing flue structure is arranged through the burner through hole, and the diameter of the burner through hole is larger than that of the combustion stabilizing flue structure; the lateral wall of the stable combustion flue structure is sleeved with a third flange, the third flange is connected with one end of a corrugated pipe, the other end of the corrugated pipe is connected with a fourth flange, the fourth flange is hermetically connected with the denitration flue lateral wall outside the burner through hole, and the third flange, the corrugated pipe and the fourth flange form a burner elastic connection sealing cover.

7. The direct-fired heating device for the denitration system of claim 3, wherein a steady-combustion central hole is axially arranged on the steady-combustion flue structure in a penetrating manner, the steady-combustion central hole forms a combustion mixing chamber, an igniter is arranged in the combustion mixing chamber, and the igniter is electrically connected with a control system; the combustion-supporting gas cavity is communicated with a combustion-supporting gas inlet, and the gas cavity is communicated with a gas inlet; the ejector is arranged in the gas cavity and the combustion-supporting gas cavity in a penetrating mode, the ejector and the stable combustion flue structure are coaxially arranged, the ejector is used for accelerating and injecting combustible gas in the gas cavity to the combustion mixing chamber, a necking injection channel is formed between the combustion-supporting gas cavity and the combustion mixing chamber, and the combustion-supporting gas in the combustion-supporting gas cavity is injected to the combustion mixing chamber through the injection channel.

8. The direct-fired heating device for deNOx systems of claim 7, wherein the steady-burning flue structure includes a steady-burning inner tube and a steady-burning outer tube that are coaxially and radially arranged at an interval, the cross section of the steady-burning inner tube is a closed profile that is spliced by a plurality of sections of circular arcs, the cross section of the steady-burning outer tube is a circular profile, a steady-burning annular space is formed between the steady-burning inner tube and the steady-burning outer tube, and the steady-burning annular space is filled with refractory casting units.

9. The direct-fired heating apparatus for denitration system of claim 7, wherein a flame detector and a temperature detector are provided in the combustion mixing chamber, both of which are electrically connected with the control system; the flame detector is used for detecting the flame combustion condition in the combustion mixing chamber, and the temperature detector is used for detecting the temperature in the combustion mixing chamber.

10. The direct-fired heating apparatus for a denitration system of claim 7, wherein the injector comprises a straight pipe section, a contraction section, a throat section, an expansion section and a rectification section, the straight pipe section is located in the combustion gas chamber, and the contraction section, the throat section, the expansion section and the rectification section are located in the combustion gas chamber; the first end of straight tube section sets up the inlet pipe mouth, the second end intercommunication of straight tube section the first end of convergent section, the diameter of convergent section is the convergent setting from one end to the second end, the second end intercommunication of convergent section the first end of larynx section, the second end intercommunication of larynx section the first end of expansion section, the diameter of expansion section is the divergent setting from one end to the second end, the second end intercommunication of expansion section the first end of rectifying section, the second end of rectifying section sets up the outlet pipe mouth.

11. The direct-fired heating device for denitration system of claim 10, wherein the rectifying section comprises an inner rectifying tube and an outer rectifying tube which are coaxially and radially arranged at intervals, the cross section of the inner rectifying tube is arranged in a closed contour formed by splicing a plurality of sections of circular arcs, the cross section of the outer rectifying tube is arranged in a circular shape, a rectifying annular space is formed between the inner rectifying tube and the outer rectifying tube, and the rectifying annular space is filled with refractory casting units.

12. The direct combustion heating apparatus for a denox system of claim 1, wherein the first angle is in a range of 10 ° to 50 °, and the second angle is in a range of 15 ° to 85 °.

13. The direct-fired heating device for denitration system of claim 1, wherein the denitration flue is a rectangular flue and is vertically arranged, 2 burner groups are arranged on two opposite side walls of the denitration flue in a penetrating manner, each burner group comprises 4 flame burners, and each flame burner forms an octagonal double-tangential circular combustion structure.