Boiler SCR (Selective Catalytic Reduction) denitration equipment with controllable flue gas temperature

Abstract

The invention discloses boiler SCR (Selective Catalytic Reduction) denitration equipment with a controllable flue gas temperature, and relates to the technical field of flue gas denitration. The device comprises a base, a gas burner and an SCR reactor are fixedly installed at the top of the base, a flue gas preheating assembly is fixedly installed in the gas burner, the gas burner communicates with the SCR reactor through a mixing pipe, a chimney is arranged on the outer side of the base, an outlet of the SCR reactor communicates with the chimney, and the SCR reactor communicates with the chimney. The smoke preheating assembly comprises smoke pipes fixedly installed at the two ends of the gas burner, and a plurality of sets of adjustable pipes are arranged between the two sets of sealing baffle discs. The gas burner is mounted at the inlet flue of the SCR reactor, and gas burns in the inner pipe through the gas burner and generates heat so as to heat flue gas fed by the flue gas pipe, so that the inlet flue gas temperature of the SCR reactor under low load reaches the lowest ammonia spraying temperature or above, and the operation condition of the whole equipment is met.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas denitration, and in particular to a boiler SCR denitration device with controllable flue gas temperature. Background Art

[0002] Nitrogen oxides, one of the main pollutants in atmospheric pollution, are extremely harmful. They not only contribute to the formation of acid rain but also pose a threat to human health. Therefore, reducing nitrogen oxide emissions has become a key goal in the environmental protection field. To effectively reduce nitrogen oxide emissions, selective catalytic reduction (SCR) denitrification technology has become a highly effective denitrification technology widely used in boilers and other industrial combustion facilities.

[0003] Flue gas temperature is a crucial parameter in the application of SCR denitrification technology. The SCR reaction is typically most efficient within a temperature range of 300°C to 400°C. Traditional SCR denitrification technology generally relies on the temperature distribution characteristics of boiler design, indirectly controlling flue gas temperature by adjusting combustion conditions within the furnace and controlling flue gas flow rate. However, this control method often struggles to achieve precise regulation, especially when boiler load fluctuates significantly or combustion is unstable. Flue gas temperature can fluctuate significantly, especially when the boiler is initially started, when flue gas temperature is relatively low (typically around 150°C), directly impacting the effectiveness of the SCR reaction.

[0004] Chinese invention patent application publication number CN110354678A provides a temperature-controlled three-way boiler SCR denitrification device, comprising a flue gas channel, an air inlet pipe mounted on the surface of the flue gas channel, a three-way pipe mounted on the top of the air inlet pipe, one end of the three-way pipe connected to a steam heater via a pipe, a solenoid valve mounted on one side of the steam heater, the top of the steam heater connected to a reactor via a pipe, and the bottom of the reactor connected to the flue gas channel via an exhaust pipe. Both this patent and the prior art utilize a method of heating the flue gas using fixed-size pipes, resulting in limited heating effectiveness. In particular, when the boiler load fluctuates significantly or combustion is unstable, the flue gas temperature fluctuates significantly and cannot be adjusted in a timely manner, resulting in poor system flexibility. Existing flue gas heating devices struggle to adapt to changes in boiler load, impacting the overall operation of the system. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and provide a boiler SCR denitrification equipment with controllable flue gas temperature.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] A boiler SCR denitrification device with controllable flue gas temperature comprises a base, a gas burner and an SCR reactor are fixedly mounted on the top of the base, a flue gas preheating assembly is fixedly mounted inside the gas burner, the gas burner and the SCR reactor are connected via a mixing pipe, a chimney is provided on the outside of the base, and the outlet of the SCR reactor is connected to the chimney;

[0008] The flue gas preheating assembly includes a flue gas pipe fixedly mounted at both ends of the gas burner, a sealing baffle fixedly mounted at one end of the flue gas pipe located inside the gas burner, an inner tube provided inside the flue gas pipe, an igniter provided on the inner tube located at the inlet of the gas burner, a first air hole and a plurality of second air holes are opened inside the sealing baffle, the plurality of second air holes are annularly distributed around the first air hole, the first air hole is connected to the inner tube, and the second air hole is connected to the flue gas pipe, and a plurality of groups of axially adjustable tubes are evenly distributed circumferentially between the two sealing baffles;

[0009] Both sides of the adjustable tube are provided with sealing outer rods along the axial direction, and the two sealing outer rods can move toward the center of the sealing baffle when they are brought together.

[0010] Furthermore, a urea barrel and a urea replenishing pump are provided at the bottom of the base. The urea replenishing pump can pump urea in the urea barrel into the SCR reactor. A temperature measurement system is provided on the outside of the gas burner. The temperature measurement system is used to monitor the flue gas temperature.

[0011] Furthermore, the interior of the sealing baffle is provided with a plurality of groups of linear sliding holes, which are arranged corresponding to the adjustable tubes; each group of linear sliding holes is composed of two linear inclined holes, which are both inclined toward the center of the sealing baffle, and sliding rods are provided at both ends of the sealing outer rod, which are slidably connected in the linear inclined holes.

[0012] Furthermore, an adjusting disk is rotatably installed on the outside of the flue pipe, and multiple groups of arc-shaped sliding holes are opened inside the adjusting disk, and the arc-shaped sliding holes are arranged corresponding to the straight sliding holes; each group of arc-shaped sliding holes consists of two arc-shaped holes, and the sliding rod passes through the straight inclined hole and is slidably connected in the arc-shaped hole.

[0013] Furthermore, two groups of support rods are provided on the inner top of the gas burner, and a transmission shaft is rotatably installed between the two groups of support rods. Transmission wheels are fixedly installed at both ends of the transmission shaft, and the outer surface of the adjusting disk is provided with external gear teeth, and the transmission wheel is meshed with the external gear teeth. A driven bevel gear is coaxially fixed to the middle of the transmission shaft, and a driving shaft is rotatably installed on the inner top of the gas burner, and an active bevel gear is fixedly installed on the bottom of the driving shaft, and the active bevel gear is meshed with the driven bevel gear; a driving motor is fixedly installed on the top of the gas burner, and the driving motor is connected to the driving shaft through a worm gear reducer.

[0014] Furthermore, the adjustable tube is made of 304 stainless steel or 316L stainless steel, with a thickness of 0.5-1 mm.

[0015] Furthermore, an elastic sealing member is provided between the sealing outer rod and the adjustable tube, and the elastic sealing member is composed of an outer layer of titanium alloy sheet and an inner layer of metal rubber.

[0016] Furthermore, the mixing tube is designed as a three-section broken line, and a stepped mixing inner plate is provided inside the mixing tube.

[0017] Furthermore, a metal rubber is provided between the sliding rod and the linear inclined hole.

[0018] Furthermore, the gas burner has an adjustable output of 295 to 1500 Nm. 3 / h natural gas burner.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. The present invention installs a gas burner (fuel is combustible gas) at the inlet flue of the SCR reactor. The gas burns in the flue pipe through the gas burner and generates heat to heat the flue gas input from the flue pipe. Under low load, the inlet flue gas temperature of the SCR reactor reaches above the minimum ammonia injection temperature, thereby meeting the overall commissioning conditions.

[0021] 2. The present invention sets a flue gas preheating component, and multiple groups of adjustable tubes form a polygonal flue gas duct along the circumference; when the flue gas temperature is relatively stable, the cross-sectional area of ​​the flue gas duct can be changed to control the flue gas flow rate, so that the gas burner can control the flue gas temperature more accurately and evenly; when the flue gas temperature fluctuates greatly, the flue gas temperature is uneven, and the multiple adjustable tubes on the circumference of the flue gas duct form multiple cavities. The internal flow velocity of the flue gas duct is faster than the flow velocity around it, forming a flow velocity difference, and the flue gas around it absorbs more heat. The two flue gases are mixed in the mixing tube, and the heat exchange efficiency of the two is balanced, resulting in better temperature control effect; when the flue gas temperature is low, the flue gas duct forms multiple independent cavities, and combustible gas is introduced into the cavities through the inner tube for combustion and heating, so that the inside and outside of the flue gas duct are heated evenly, and the flue gas can be heated more efficiently.

[0022] 3. The present invention can introduce high-temperature exhaust gas from the boiler system or other systems in the plant into the flue gas preheating assembly through the provision of an inner pipe, making the overall device more flexible and meeting the needs of different plant areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 Schematic diagram of the internal structure of the mixing tube of the present invention;

[0025] Figure 3 It is a schematic structural diagram of the flue gas preheating assembly of the present invention;

[0026] Figure 4 is an exploded view of the flue gas preheating assembly of the present invention;

[0027] Figure 5 Schematic diagram of the cross-sectional structure of the smoke pipe of the present invention;

[0028] Figure 6 It is a structural schematic diagram of the adjustment disk of the present invention;

[0029] Figure 7 This is a schematic diagram of the first state of the adjustable tube of the present invention;

[0030] Figure 8 This is a schematic diagram of the second state of the adjustable tube of the present invention;

[0031] Figure 9 This is a schematic diagram of the third state of the adjustable tube of the present invention.

[0032] Figure numerals: 1. base; 2. gas burner; 21. bracket rod; 22. transmission shaft; 23. transmission wheel; 24. driven bevel gear; 25. drive shaft; 26. driving bevel gear; 3. flue gas preheating assembly; 31. flue gas pipe; 32. inner tube; 321. igniter; 33. sealing baffle; 34. first air hole; 35. second air hole; 36. linear sliding hole; 37. adjusting disk; 38. arc sliding hole; 39. sealing outer rod; 310. adjustable tube; 311. sliding rod; 312. elastic sealing; 4. SCR reactor; 5. mixing tube; 51. mixing inner plate; 6. temperature measurement system; 7. chimney; 8. urea ton barrel; 9. urea replenishing pump. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] Example 1

[0035] like Figures 1-9 As shown, a boiler SCR denitrification device with controllable flue gas temperature includes a base 1, a gas burner 2 and an SCR reactor 4 are fixedly mounted on the top of the base 1, a flue gas preheating assembly 3 is fixedly mounted inside the gas burner 2, the gas burner 2 and the SCR reactor 4 are connected via a mixing pipe 5, a chimney 7 is provided on the outside of the base 1, and the outlet of the SCR reactor 4 is connected to the chimney 7;

[0036] The flue gas preheating assembly 3 includes a flue gas pipe 31 fixedly mounted at both ends of the gas burner 2, a sealing baffle 33 fixedly mounted at one end of the flue gas pipe 31 located inside the gas burner 2, an inner tube 32 is arranged inside the flue gas pipe 31, and an igniter 321 is arranged on the inner tube 32 located at the inlet of the gas burner 2, a first air hole 34 and a plurality of second air holes 35 are opened inside the sealing baffle 33, and the plurality of second air holes 35 are annularly distributed around the first air hole 34, the first air hole 34 is connected to the inner tube 32, and the second air holes 35 are connected to the flue gas pipe 31, and a plurality of groups of adjustable tubes 310 are arranged between the two sealing baffles 33, preferably six groups; the adjustable tube 310 is along the axial direction, and the plurality of groups of adjustable tubes 310 form a polygonal flue gas duct along the circumference.

[0037] Sealing outer rods 39 are provided at both ends of the adjustable tube 310 , and the two sealing outer rods 39 can move toward the center of the sealing baffle 33 while being brought together.

[0038] Furthermore, the adjustable tube 310 is made of 304 stainless steel or 316L stainless steel with a thickness of 0.5-1 mm. 304 or 316L stainless steel has excellent corrosion resistance and high temperature resistance, and also has a certain elasticity and can withstand large deformation, and is suitable for environments containing corrosive gases.

[0039] When the boiler is just started, the temperature of the flue gas sent from the flue gas pipe 31 near the igniter 321 is only 150°C, which is relatively low. At this time, the flue gas needs to be preheated so that the flue gas can be quickly heated to 300°C-400°C. The two sealed outer rods 39 of the same set of adjustable tubes 310 are close together, and the sealed outer rods 39 transform the adjustable tube 310 from an elliptical shape into a full circle. At the same time, the adjustable tube 310 moves toward the center of the sealing baffle 33. The adjustable tube 310 corresponds to the second air hole 35. At this time, the flue gas preheating assembly 3 forms a hexagonal tube with six independent cylindrical chambers. The middle of the six independent cylindrical chambers forms an internal heating cavity (the inner cavity of the hexagonal tube), as shown in the attached figure. Figure 9 As shown, the gas burner 2 heats the cylindrical chamber from the outside, the inner tube 32 is connected to the gas and ignited by the igniter 321, and the flame enters the inner heating cavity through the inner tube 32 and the first air hole 34 and heats the cylindrical chamber from the inside, so that the flue gas is heated quickly and evenly; at this time, the cross-street area of ​​the cylindrical chamber is twice the cross-street area of ​​the second air hole 35. During the flow of flue gas, when the fluid enters a larger space from a small-diameter pipe, the expansion of the pipe will cause the velocity of the fluid to change. In order to maintain a consistent flow rate, the flue gas flow rate must be slowed down; and after the flue gas enters the large space, the flow may become more turbulent, generating turbulence or vortexes, so that the flue gas is evenly mixed in the cylindrical chamber, and then discharged through the second air hole 35 of the sealing baffle 33 at the other end, so that the flue gas is discharged from a small opening, further improving the heat exchange efficiency.

[0040] When the flue gas temperature fluctuates greatly during the use of the boiler, the two sealed outer rods 39 of the same set of adjustable tubes 310 are brought together, and the sealed outer rods 39 reduce the long diameter of the elliptical adjustable tubes 310 and increase the wide diameter. A polygonal flue gas cavity is formed in the middle of the multiple sets of adjustable tubes 310, and only a small part of the adjustable tubes 310 is connected to the second air hole 35. Figure 8 As shown, the second air hole 35 is connected to the adjustable pipe 310 and the smoke passage cavity at the same time. At this time, the smoke enters the smoke pipe 31, and the smoke flows in the smoke passage cavity in a straight channel with a relatively fast flow rate. The smoke enters a larger space with a small diameter in the adjustable pipe 310, and the flow rate is slow, but the heat exchange efficiency is high. Even when the smoke fluctuates greatly, a part of it can always fully absorb heat. According to the change of the smoke temperature, the connection ratio of the adjustable pipe 310 and the smoke passage cavity to the second air hole 35 is adjusted in real time. When the temperature is high, the proportion of the adjustable pipe 310 is reduced, and more smoke passes through quickly; when the temperature is low, the proportion of the adjustable pipe 310 is increased, and more smoke enters the adjustable pipe 310 and is heated, and then mixed evenly in the mixing pipe 5 and enters the SCR reactor 4 for desulfurization, and finally discharged through the chimney 7.

[0041] When the flue gas temperature is uniform and the temperature difference is small, the adjustable tube 310 is a small ellipse. The adjustable tube 310 is not connected to the second air hole 35. The space formed between the multiple groups of adjustable tubes 310 forms a flue gas straight path. The flue gas enters the mixing tube 5 through the flue gas straight path. The internal space of the adjustable tube 310 forms a heating buffer space, which makes the flue gas heated more evenly. By controlling the expansion and contraction of the adjustable tube 310, the flue gas temperature can be controlled within a smaller range. Within this adjustment range, the adjustable tube 310 always does not communicate with the second air hole 35. In this way, by bringing the two sealing outer rods 39 together and moving them toward the center of the sealing baffle 33, the effective cross-sectional area of ​​the flue gas straight path can be reduced, changing the size of the heating buffer space to adapt to flue gas heating at different temperatures.

[0042] In summary, the SCR denitrification equipment of the present invention can be applied to different working occasions, and can achieve simple and effective control of the flue gas temperature, with simple overall control and a wide control range. In addition, the gas burner 2 of the present invention adopts an adjustable output of 295~1500Nm 3 / h, a combustion rate of 99.99% and a large natural gas burner are used to meet the temperature rise requirements of flue gas heating. The overall system can realize gas flame detection and reliable ignition, and has the characteristics of strong rigor, safety and high reliability.

[0043] Example 2

[0044] Based on the above embodiment 1, the difference is that a urea ton barrel 8 and a urea replenishing pump 9 are provided at the bottom of the base 1. The urea replenishing pump 9 can pump urea in the urea ton barrel 8 into the SCR reactor 4. A temperature measurement system 6 is provided on the outside of the gas burner 2. The temperature measurement system 6 is used to monitor the flue gas temperature and monitor the flue gas parameters in real time so that the flue gas can be stably maintained at a suitable treatment temperature.

[0045] The above-mentioned temperature measurement system 6 is an existing technology, which mainly includes a temperature sensor and a signal conversion device. The temperature of the flue gas is directly measured by the temperature sensor. The signal conversion device converts the temperature signal measured by the sensor into a standard electrical signal (such as 0-10V, 4-20mA, etc.) to facilitate subsequent processing and display, thereby realizing real-time monitoring of the flue gas temperature. The details will not be repeated here.

[0046] Example 3

[0047] Based on the above-mentioned embodiment 1, the difference is that a plurality of groups of linear sliding holes 36 are provided inside the sealing baffle 33, and the linear sliding holes 36 are arranged corresponding to the adjustable tube 310. Each group of linear sliding holes 36 is composed of two linear inclined holes, and the two linear inclined holes are inclined toward the center of the sealing baffle 33. Both ends of the sealing outer rod 39 are provided with sliding rods 311, and the sliding rods 311 are slidably connected in the linear inclined holes.

[0048] Furthermore, an adjusting disk 37 is coaxially mounted on the outside of the flue pipe 31, and a plurality of groups of arc-shaped sliding holes 38 are provided inside the adjusting disk 37. The arc-shaped sliding holes 38 are arranged corresponding to the linear sliding holes 36. Each group of arc-shaped sliding holes 38 consists of two arc-shaped holes. The sliding rod 311 passes through the linear inclined hole and is slidably connected in the arc-shaped hole.

[0049] Furthermore, two groups of support rods 21 are provided at the inner top of the gas burner 2, and a transmission shaft 22 is rotatably installed between the two groups of support rods 21. Transmission wheels 23 are fixedly installed at both ends of the transmission shaft 22. The outer surface of the adjusting disk 37 is provided with external gear teeth, and the transmission wheel 23 is meshed with the external gear teeth. A driven bevel gear 24 is coaxially fixedly installed in the middle of the transmission shaft 22. A drive shaft 25 is also rotatably installed at the inner top of the gas burner 2, and an active bevel gear 26 is fixedly installed at the bottom of the drive shaft 25. The active bevel gear 26 is meshed with the driven bevel gear 24. A drive motor is fixedly installed on the top of the gas burner 2, and the drive motor is connected to the drive shaft 25 through a worm gear reducer.

[0050] This embodiment provides a specific adjustment method for an adjustable tube 310: a driving motor is arranged outside the gas burner 2, and the connection between the driving motor and the worm gear reducer and the gas burner 2 can be treated with heat-insulating materials. The driving motor drives the driving shaft 25 to rotate through the worm gear reducer, and the driving shaft 25 drives the active bevel gear 26 to rotate. The active bevel gear 26 drives the transmission shaft 22 to rotate through the driven bevel gear 24, and the transmission shaft 22 drives the adjustment disk 37 to rotate through the transmission wheel 23 and the outer gear teeth. The adjustment disk 37 drives the corresponding sliding rod 311 to slide along the straight inclined hole through the arc-shaped sliding hole 38, and the sliding rod 311 drives the sealing outer rod 39 to slide along the straight inclined hole, so that the two sealing outer rods 39 of the same group of adjustable tubes 310 can move toward the center of the sealing baffle 33 when they are close together. The overall control is simple and through the design of the worm gear reducer, the adjustment disk 37 will not rotate when the motor is powered off.

[0051] Example 4

[0052] Based on the above-mentioned embodiment 3, the difference is that an elastic seal 312 is provided between the sealing outer rod 39 and the adjustable tube 310. The elastic seal 312 is composed of an outer layer of titanium alloy sheet and an inner layer of metal rubber. The elastic seal 312 can improve the sealing between the sealing outer rod 39 and the adjustable tube 310.

[0053] Example 5

[0054] Based on the above-mentioned embodiment 1, the difference is that the mixing tube 5 is designed as a three-segment broken line, and a stepped mixing inner plate 51 is provided inside the mixing tube 5, so that the flue gas can be better mixed when entering the mixing tube 5, and at the same time, it is convenient to connect the gas burner 2 and the SCR reactor 4.

[0055] Example 6

[0056] Based on the above embodiment 3, the difference is that a metal rubber is provided between the sliding rod 311 and the linear inclined hole, so as to prevent smoke from overflowing from the linear inclined hole and improve the stability of the device.

[0057] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily 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 is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A boiler SCR denitrification device with controllable flue gas temperature, comprising a base (1), characterized in that: A gas burner (2) and an SCR reactor (4) are fixedly mounted on the top of the base (1), and a flue gas preheating assembly (3) is fixedly mounted inside the gas burner (2); the gas burner (2) and the SCR reactor (4) are connected via a mixing pipe (5); a chimney (7) is provided on the outside of the base (1), and the outlet of the SCR reactor (4) is connected to the chimney (7); The flue gas preheating assembly (3) comprises a flue gas pipe (31) fixedly mounted at both ends of the gas burner (2); a sealing baffle (33) is fixedly mounted on one end of the flue gas pipe (31) located inside the gas burner (2); an inner tube (32) is arranged inside the flue gas pipe (31); an igniter (321) is arranged on the inner tube (32) located at the inlet of the gas burner (2); a first air hole (34) and a plurality of second air holes (35) are opened inside the sealing baffle (33); the plurality of second air holes (35) are annularly distributed around the first air hole (34); the first air hole (34) is connected to the inner tube (32); the second air hole (35) is connected to the flue gas pipe (31); and a plurality of groups of axially adjustable tubes (310) are uniformly distributed circumferentially between the two sealing baffles (33); Both sides of the adjustable tube (310) are provided with axially extending sealing outer rods (39), and the two sealing outer rods (39) can move toward the center of the sealing baffle (33) when they are brought together.

2. The boiler SCR denitrification equipment with controllable flue gas temperature according to claim 1, characterized in that: A urea ton barrel (8) and a urea replenishing pump (9) are provided at the bottom of the base (1). The urea replenishing pump (9) is used to pump urea in the urea ton barrel (8) into the SCR reactor (4). A temperature measuring system (6) for monitoring flue gas temperature is provided outside the gas burner (2).

3. The boiler SCR denitrification equipment with controllable flue gas temperature according to claim 1, characterized in that: The sealing baffle (33) is provided with a plurality of groups of linear sliding holes (36) inside, and the linear sliding holes (36) are arranged corresponding to the adjustable tube (310); each group of the linear sliding holes (36) is composed of two linear inclined holes, and the two linear inclined holes are inclined toward the center of the sealing baffle (33); both ends of the sealing outer rod (39) are provided with sliding rods (311), and the sliding rods (311) are slidably connected in the linear inclined holes.

4. The boiler SCR denitrification equipment with controllable flue gas temperature according to claim 3, characterized in that: An adjusting disk (37) is rotatably mounted on the outer side of the flue gas pipe (31), and a plurality of groups of arc-shaped sliding holes (38) are provided inside the adjusting disk (37), and the arc-shaped sliding holes (38) are arranged corresponding to the linear sliding holes (36); each group of the arc-shaped sliding holes (38) consists of two arc-shaped holes, and the sliding rod (311) passes through the linear inclined hole and is slidably connected in the arc-shaped hole.

5. The boiler SCR denitrification equipment with controllable flue gas temperature according to claim 4, characterized in that: Two groups of support rods (21) are provided on the inner top of the gas burner (2), a transmission shaft (22) is rotatably mounted between the two groups of support rods (21), and transmission wheels (23) are fixedly mounted on both ends of the transmission shaft (22); the outer surface of the adjustment disk (37) is provided with external gear teeth, and the transmission wheel (23) is meshed with the external gear teeth; a driven bevel gear (24) is coaxially fixedly mounted in the middle of the transmission shaft (22); a driving shaft (25) is rotatably mounted on the inner top of the gas burner (2), and a driving bevel gear (26) is fixedly mounted on the bottom of the driving shaft (25), and the driving bevel gear (26) is meshed with the driven bevel gear (24); a driving motor is fixedly mounted on the top of the gas burner (2), and the driving motor is transmission-connected to the driving shaft (25) through a worm gear reducer.

6. The boiler SCR denitrification equipment with controllable flue gas temperature according to claim 5, characterized in that: The adjustable tube (310) is made of 304 stainless steel or 316L stainless steel, and has a thickness of 0.5-1 mm.

7. The boiler SCR denitration equipment with controllable flue gas temperature according to claim 6, characterized in that: An elastic sealing member (312) is provided between the sealing outer rod (39) and the adjustable tube (310), and the elastic sealing member (312) is composed of an outer layer of titanium alloy sheet and an inner layer of metal rubber.

8. The boiler SCR denitration equipment with controllable flue gas temperature according to claim 7, characterized in that: The mixing tube (5) is designed as a three-section broken line, and a stepped mixing inner plate (51) is provided inside the mixing tube (5).

9. The boiler SCR denitration equipment with controllable flue gas temperature according to claim 8, characterized in that: Metal rubber is provided between the slide rod (311) and the linear inclined hole.

10. The boiler SCR denitration equipment with controllable flue gas temperature according to claim 9, characterized in that: The gas burner (2) has an adjustable output of 295-1500 Nm 3 / h natural gas burner.

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