Flue gas heating device for denitration inlet flue

Abstract

The invention discloses a denitration inlet flue flue gas heating device, and relates to the related technical field of industrial flue gas denitration treatment.The denitration inlet flue gas heating device comprises a denitration tower, the lower side of the front end of the denitration tower communicates with a smoke guiding pipeline, a heat exchange assembly is arranged on the side, close to the denitration tower, of the interior of the smoke guiding pipeline, and the upper end of the denitration tower communicates with a smoke discharging pipeline; a smoke guiding pipeline is arranged in the denitration tower, a catalytic device is arranged on the upper side of the interior of the denitration tower, a fuel gas coil pipe is arranged on the lower side of the interior of the denitration tower, and the fuel gas coil pipe is located on the lower side of the connecting position of the smoke guiding pipeline and the denitration tower. And the flue gas temperature is increased to meet the denitration reaction requirement. The adjustable heat exchange box is formed through the combination of the fixed heat-conducting fins, the movable heat-conducting fins and the sealing structure, smoke and high-temperature gas are subjected to sufficient heat exchange, preheating energy consumption is reduced, meanwhile, different smoke flows are adapted through dynamic adjustment, and it is ensured that the heat exchange efficiency is stable.

Description

Technical Field

[0001] The present invention belongs to the technical field related to the denitrification treatment of industrial flue gas, and particularly relates to a flue gas heating device for the denitrification inlet flue. Background Technique

[0002] In the traditional industrial flue gas denitrification treatment process, the SCR denitrification technology is widely used due to its high reaction efficiency and strong adaptability. However, there are still several technical bottlenecks to be solved in the existing technology. Conventional denitrification systems usually use external heat sources to preheat the inlet flue gas to meet the denitrification reaction temperature requirements. This heating method not only has high energy consumption and large operating costs, but also is difficult to adapt to the problem of inaccurate temperature control caused by fluctuations in flue gas flow.

[0003] During the denitrification reaction process, due to the limited contact time between the flue gas and the denitrifying agent, there are often defects such as incomplete reaction and unstable denitrification efficiency. Especially when the flue gas load changes, the system is difficult to quickly adjust the reaction conditions, resulting in fluctuations in the denitrification effect.

[0004] The existing technology usually directly discharges or simply treats the high-temperature mixed gas generated by the reaction, and fails to effectively recover and utilize the large amount of waste heat resources contained therein, resulting in energy waste. In addition, in the heat exchange link, traditional fixed heat exchangers cannot automatically adjust the heat exchange efficiency according to the change of flue gas flow, which is likely to cause insufficient preheating or energy waste.

[0005] In view of the above problems, this patent proposes a denitrification treatment device that can achieve self-preheating of flue gas, adaptive adjustment of reaction conditions, and efficient recovery and utilization of waste heat, so as to solve the technical problems such as high energy consumption, unstable efficiency, and large operating costs existing in the existing technology. Summary of the Invention

[0006] The purpose of the present invention is to provide a flue gas heating device for the denitrification inlet flue, so as to solve the problems of high energy consumption, unstable efficiency, and large operating costs of traditional industrial flue gas denitrification mentioned in the above background technique.

[0007] To achieve the above object, the present invention provides the following technical solution: A flue gas heating device at the denitration inlet flue, including a denitration tower. A smoke guiding pipe is connected to the lower side of the front end of the denitration tower. A heat exchange component is arranged inside the smoke guiding pipe near the denitration tower side. A smoke exhaust pipe is connected to the upper end of the denitration tower. A catalytic device is arranged on the upper side inside the denitration tower. A gas coil is arranged on the lower side inside the denitration tower, and the gas coil is located below the connection between the smoke guiding pipe and the denitration tower. The rear end of the gas coil is connected to a gas connection pipe, and the rear end of the gas connection pipe penetrates outside the rear end of the denitration tower. The upper end of the gas coil is connected to a plurality of gas burners with openings upward. A denitration agent coil is arranged at the middle inside the denitration tower, and the denitration agent coil is located below the catalytic device. The rear end of the denitration agent coil is connected to a denitration agent connection pipe, and the rear end of the denitration agent connection pipe penetrates outside the rear end of the denitration tower. The lower end of the denitration agent coil is connected to a plurality of denitration agent spray nozzles with openings downward. A flue gas-ammonia mixture circulation component is arranged between the denitration agent coil and the catalytic device.

[0008] Preferably, the flue gas-ammonia mixture circulation component includes a flue gas-ammonia mixture collection box, flow disturbance holes, centrifugal fan blades, and flow disturbance fan blades. A flue gas-ammonia mixture collection box is arranged above the denitration agent coil. A plurality of flow disturbance holes penetrate through the upper and lower parts of the flue gas-ammonia mixture collection box. A plurality of fan upper shells are connected to the inner wall of the upper end of the flue gas-ammonia mixture collection box, and the plurality of fan upper shells are respectively located at the upper end openings of the plurality of flow disturbance holes and are coaxial with the plurality of flow disturbance holes respectively.

[0009] Preferably, a plurality of fan lower shells are connected to the inner wall of the lower end of the flue gas-ammonia mixture collection box, and the plurality of fan lower shells are respectively located at the lower end openings of the plurality of flow disturbance holes and are coaxial with the plurality of fan upper shells respectively. The plurality of fan lower shells are respectively located below the outside of the plurality of fan upper shells. A rotating shaft frame is connected to the inner part of the lower end of each of the plurality of fan upper shells. A linkage rotating shaft penetrates through the center of each of the plurality of rotating shaft frames up and down.

[0010] Preferably, the linkage rotating shaft is rotatably connected inside the rotating shaft frame. A plurality of centrifugal fan blades arranged in an "L" shape are connected to the lower side of the outside of the linkage rotating shaft, and the plurality of centrifugal fan blades are rotatably connected inside the lower end of the flow disturbance hole and are rotatably connected between the fan upper shell and the fan lower shell. A plurality of flow disturbance fan blades are connected to the upper side of the outside of the linkage rotating shaft, and the plurality of flow disturbance fan blades are rotatably connected inside the upper end of the flow disturbance hole.

[0011] Preferably, the heat exchange component includes a rear sealing plate, fixed heat conduction sheets, an outer sealing cylinder, a front sealing plate, movable heat conduction sheets, and movable heat exchange holes. A high-temperature diversion pipe is connected to the front end of the flue gas-ammonia mixture collection box, and the other end of the high-temperature diversion pipe penetrates outside the front end of the denitration tower and extends into the smoke guiding pipe through the upper end of the smoke guiding pipe. A connection clamping ring is connected to the outside of the end of the high-temperature diversion pipe far from the flue gas-ammonia mixture collection box.

[0012] Preferably, a connection chuck is sleeved outside the front end of the connection snap ring, and a high-temperature resistant rubber sealing ring is arranged between the connection snap ring and the connection chuck. A rear sealing plate is connected to the outer side of the front end of the connection chuck, and a plurality of fixed heat conducting sheets are connected to the front end of the rear sealing plate. The plurality of fixed heat conducting sheets are rotationally symmetrically arranged around the central axis of the rear sealing plate.

[0013] Preferably, fixed heat exchange holes penetrate through the front and rear of each of the plurality of fixed heat conducting sheets, and the plurality of fixed heat exchange holes are all opened at the rear end of the rear sealing plate. An outer layer sealing cylinder is arranged outside the plurality of fixed heat conducting sheets, and the outer layer sealing cylinder is connected to the outer side of the front end of the rear sealing plate. The rear side of the upper end of the outer layer sealing cylinder communicates with a low-temperature return pipe, and the other end of the low-temperature return pipe communicates with the upper side of the front end of the denitration tower, and the connection part is located between the flue gas-ammonia mixture collection box and the catalytic device. A front sealing plate is arranged at the center of the front ends of the plurality of fixed heat conducting sheets.

[0014] Preferably, a plurality of movable heat conducting sheets are connected to the rear end of the front sealing plate, and the plurality of movable heat conducting sheets are rotationally symmetrically arranged around the central axis of the front sealing plate. Movable heat exchange holes are formed inside each of the plurality of movable heat conducting sheets, and the plurality of movable heat conducting sheets are sleeved outside the plurality of fixed heat conducting sheets through the plurality of movable heat exchange holes. High-temperature resistant rubber sealing rings are arranged between the plurality of movable heat conducting sheets and the plurality of fixed heat conducting sheets, and the plurality of movable heat conducting sheets are all located in front of the low-temperature return pipe.

[0015] Preferably, the plurality of movable heat exchange holes are all opened at the front end of the front sealing plate. An inner layer sealing cylinder is arranged outside the plurality of movable heat conducting sheets, and the inner layer sealing cylinder is connected to the outside of the rear end of the front sealing plate and is clamped inside the outer layer sealing cylinder. A high-temperature resistant rubber sealing ring is arranged between the inner layer sealing cylinder and the outer layer sealing cylinder.

[0016] Preferably, a through support frame is connected inside the opening at one end of the high-temperature diversion pipe far away from the flue gas-ammonia mixture collection box. A positioning sliding rod penetrates through the center of the through support frame and is slidably connected with the positioning sliding rod. The front end of the positioning sliding rod is connected to the center of the rear end of the front sealing plate. A spring compression plate is connected to the rear end of the positioning sliding rod, and the spring compression plate is located behind the through support frame. A positioning spring is arranged between the through support frame and the spring compression plate.

[0017] Compared with the prior art, the present invention provides a flue gas heating device for the denitration inlet flue, having the following beneficial effects: 1. The present invention arranges a heat exchange component in the smoke guiding pipeline, and uses the high-temperature mixed gas (flue gas-ammonia mixture) generated in the denitration tower to preheat the inlet flue gas, so as to increase the flue gas temperature to meet the denitration reaction requirements. Through the combination of fixed heat conducting sheets, movable heat conducting sheets and sealing structures, an adjustable heat exchange box is formed, enabling the flue gas to fully exchange heat with the high-temperature gas, reducing the preheating energy consumption, and at the same time dynamically adjusting to adapt to different flue gas flows to ensure stable heat exchange efficiency.

[0018] 2. The present invention provides a gas coil and multiple gas burners at the bottom of the denitration tower. When the temperature of industrial flue gas is too low, the temperature of the industrial flue gas can be rapidly increased by burning gas, ensuring that the denitration reaction proceeds at an appropriate temperature. The gas flow can be automatically adjusted according to the flue gas flow, ensuring that the denitration efficiency is not affected by operating conditions fluctuations and avoiding energy waste at the same time.

[0019] 3. The design of the denitration agent coil and multiple downward spraying denitration agent nozzles in the present invention enables the combination of ammonia and air to contact the flue gas in a countercurrent manner. Combining with the eddy current generated by the flue gas-ammonia mixture circulation component, the flue gas and the combination of ammonia and air are fully mixed, improving the utilization rate of the denitration agent and ensuring the full conversion of nitrogen oxides.

[0020] 4. The present invention circulates the high-temperature mixed gas in the denitration tower into the heat exchange component through the flue gas-ammonia mixture collection box, turbulence holes and centrifugal fan blade structure, and uses its waste heat to preheat the newly entering flue gas. Not only the waste heat is recovered, but also the mixing time of the flue gas and the combination of ammonia and air is prolonged through the turbulence effect, further improving the denitration efficiency.

[0021] 5. The heat exchange box of the present invention adopts a telescopic structure, and dynamically adjusts the heat exchange area through a displacement spring and a pneumatic balance mechanism. When the flue gas flow increases, the system automatically increases the heat exchange area to improve the preheating efficiency; when the flow decreases, it shrinks to avoid overheating, ensuring that the denitration reaction temperature is always within the optimal range.

[0022] 6. The heat exchange component adopts a multi-layer sealing structure (such as high-temperature resistant rubber sealing rings, inner / outer sealing cylinders) to ensure no leakage of high-temperature gas. The rotationally symmetric layout of the fixed heat conduction fins and the movable heat conduction fins optimizes the air flow distribution and improves the heat exchange uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional structural schematic diagram of the flue gas heating device at the denitration inlet flue of the present invention.

[0024] Figure 2 It is a three-dimensional sectional structural schematic diagram of the flue gas heating device at the denitration inlet flue of the present invention.

[0025] Figure 3 It is a connection structural schematic diagram of the heat exchange component and the flue gas-ammonia mixture circulation component of the present invention.

[0026] Figure 4 It is a three-dimensional sectional structural schematic diagram of the flue gas-ammonia mixture circulation component of the present invention.

[0027] Figure 5 It is for the present invention Figure 4 Enlarged schematic diagram at position A in

[0028] Figure 6 Schematic diagram of the linkage rotating shaft connection structure of the present invention.

[0029] Figure 7 Schematic three-dimensional sectional structure diagram of the heat exchange component of the present invention.

[0030] Figure 8 Schematic diagram of the connection structure of the rear sealing plate of the present invention.

[0031] Figure 9 Schematic diagram of the connection structure of the front sealing plate of the present invention.

[0032] In the figure: 1, denitration tower; 2, smoke guiding pipe; 3, smoke exhaust pipe; 4, gas coil pipe; 5, gas connecting pipe; 6, gas burner head; 7, denitrating agent coil pipe; 8, denitrating agent connecting pipe; 9, denitrating agent spray head; 10, smoke-ammonia mixture collection box; 11, flow disturbing through hole; 12, upper shell of the fan; 13, lower shell of the fan; 14, rotating shaft bracket; 15, linkage rotating shaft; 16, centrifugal fan blade; 17, flow disturbing fan blade; 18, high-temperature guiding pipe; 19, connecting clamping ring; 20, connecting clamping head; 21, rear sealing plate; 22, fixed heat conduction fin; 23, fixed heat exchange hole; 24, outer sealing cylinder; 25, low-temperature return pipe; 26, front sealing plate; 27, movable heat conduction fin; 28, movable heat exchange hole; 29, inner sealing cylinder; 30, through support frame; 31, position adjusting sliding rod; 32, spring compression plate; 33, position adjusting spring; 34, catalytic device. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] The present invention provides as Figures 1-9A denitration inlet flue gas heating device shown in the figure includes a denitration tower 1. A smoke guiding pipe 2 is connected to the lower side of the front end of the denitration tower 1. A heat exchange component is arranged on the side close to the denitration tower 1 inside the smoke guiding pipe 2. A smoke exhaust pipe 3 is connected to the upper end of the denitration tower 1. A catalytic device 34 is arranged on the upper side inside the denitration tower 1. A gas coil 4 is arranged on the lower side inside the denitration tower 1, and the gas coil 4 is located below the connection between the smoke guiding pipe 2 and the denitration tower 1. The rear end of the gas coil 4 is connected to a gas connection pipe 5, and the rear end of the gas connection pipe 5 penetrates outside the rear end of the denitration tower 1. The upper end of the gas coil 4 is connected to a plurality of gas burners 6 with openings upward. A denitration agent coil 7 is arranged in the middle inside the denitration tower 1, and the denitration agent coil 7 is located below the catalytic device 34. The rear end of the denitration agent coil 7 is connected to a denitration agent connection pipe 8, and the rear end of the denitration agent connection pipe 8 penetrates outside the rear end of the denitration tower 1. The lower end of the denitration agent coil 7 is connected to a plurality of denitration agent spray nozzles 9 with openings downward. A smoke-ammonia mixture circulation component is arranged between the denitration agent coil 7 and the catalytic device 34. During the wet denitration process of industrial flue gas, the industrial flue gas is introduced into the denitration tower 1 through the smoke guiding pipe 2, and the flue gas introduced into the denitration tower 1 is preheated through the heat exchange component inside the smoke guiding pipe 2. At the same time, the combination of ammonia and air is introduced into the denitration agent coil 7 through the denitration agent connection pipe 8, and the combination of ammonia and air is sprayed into the denitration tower 1 through a plurality of denitration agent spray nozzles 9, so that the combination of ammonia and air collides and mixes with the industrial flue gas to form a mixed gas, which then flows upward.

[0035] At this time, the upward flowing mixed gas drives the operation of the smoke-ammonia mixture circulation component, so that a part of the mixed gas will be inhaled by the operating smoke-ammonia mixture circulation component for thermal recycling, preheating the industrial flue gas inside the smoke guiding pipe 2, reducing the preheating cost of the industrial flue gas, thereby reducing the denitration cost. At the same time, the mixed gas can continue to mix inside the smoke-ammonia mixture circulation component, and the mixing path is increased, improving the mixing uniformity of the industrial flue gas and the combination of ammonia and air. And after the thermal recycling of the mixed gas is completed, it is introduced back into the denitration tower 1 for denitration reaction again. The mixed gas that is not inhaled continues to flow upward, and is mixed again with the introduced-back mixed gas between the smoke-ammonia mixture circulation component and the catalytic device 34. The gas after re-mixing flows upward through the inside of the catalytic device 34, and undergoes a denitration reaction under the action of the catalyst and high temperature inside the catalytic device 34, thereby converting the nitrogen oxides in the industrial flue gas into harmless gases. Among them, the catalytic device 34 is a hollow cylindrical shell made of a perforated plate, and a catalyst is filled inside it. The catalyst is a vanadium-based catalyst or a titanium-based catalyst or a molecular sieve catalyst or an activated carbon / coke catalyst.

[0036] In addition, during the process of industrial flue gas entering the interior of the denitration tower 1, in the first 10 minutes when the industrial flue gas just starts to enter the interior of the denitration tower 1 and when the flow rate of the industrial flue gas is small, the temperature of the industrial flue gas is relatively low and cannot reach the temperature required for the denitration reaction. At this time, the gas coil 4 will heat-treat the industrial flue gas to ensure that the temperature of the industrial flue gas can quickly rise to the temperature required for the denitration reaction. The gas is introduced into the interior of the gas coil 4 through the gas connection pipe 5, and the gas is introduced into the bottom of the denitration tower 1 through multiple gas burners 6 for combustion to heat the industrial flue gas, enabling the industrial flue gas to quickly reach the reaction temperature, improving the reaction efficiency. The harmless gas after the denitration reaction is introduced into the next treatment process through the exhaust pipe 3.

[0037] Such as Figures 3-6As shown in the figure, the flue gas-ammonia mixture circulation component includes a flue gas-ammonia mixture collection box 10, a flow-disturbing through hole 11, a centrifugal fan blade 16 and a flow-disturbing fan blade 17. A flue gas-ammonia mixture collection box 10 is arranged above the denitration agent coiled pipe 7. A plurality of flow-disturbing through holes 11 penetrate through the flue gas-ammonia mixture collection box 10 vertically. A plurality of upper fan housings 12 are connected to the inner wall of the upper end of the flue gas-ammonia mixture collection box 10, and the plurality of upper fan housings 12 are respectively located at the upper openings of the plurality of flow-disturbing through holes 11 and share the same central axis with the plurality of flow-disturbing through holes 11. A plurality of lower fan housings 13 are connected to the inner wall of the lower end of the flue gas-ammonia mixture collection box 10, and the plurality of lower fan housings 13 are respectively located at the lower openings of the plurality of flow-disturbing through holes 11 and share the same central axis with the plurality of upper fan housings 12. The plurality of lower fan housings 13 are respectively located at the lower outer sides of the plurality of upper fan housings 12. A rotating shaft bracket 14 is connected to the inner part of the lower end of each of the plurality of upper fan housings 12. A linkage rotating shaft 15 penetrates vertically through the center of the inner part of each of the plurality of rotating shaft brackets 14. The linkage rotating shaft 15 is rotatably connected to the inside of the rotating shaft bracket 14. A plurality of centrifugal fan blades 16 arranged in an "L" shape are connected to the lower outer side of the linkage rotating shaft 15, and the plurality of centrifugal fan blades 16 are all rotatably connected to the inner part of the lower end of the flow-disturbing through hole 11 and are rotatably connected between the upper fan housing 12 and the lower fan housing 13. A plurality of flow-disturbing fan blades 17 are connected to the upper outer side of the linkage rotating shaft 15, and the plurality of flow-disturbing fan blades 17 are all rotatably connected to the inner part of the upper end of the flow-disturbing through hole 11. The front end of the flue gas-ammonia mixture collection box 10 is communicated with a high-temperature diversion pipe 18, and the other end of the high-temperature diversion pipe 18 penetrates through the outside of the front end of the denitration tower 1 and extends through the upper end of the smoke guiding pipe 2 to the inside of the smoke guiding pipe 2. During the process of introducing the high-temperature mixed gas into the heat exchange component, since induced draft fans are arranged at both the front end of the smoke guiding pipe 2 and the rear end of the smoke exhaust pipe 3, and the flow of the flue gas is guided by the induced draft fans, the flue gas inside the denitration tower 1 flows from bottom to top and is in counterflush mixing with the combination of ammonia gas and air to form a high-temperature mixed gas, that is, a flue gas-ammonia mixture. At this time, a part of the high-temperature mixed gas flows upward through the plurality of flow-disturbing through holes 11 and is introduced into the space between the flue gas-ammonia mixture collection box 10 and the catalytic device 34 through the plurality of flow-disturbing through holes 11, and at the same time drives the plurality of flow-disturbing fan blades 17 to rotate around the linkage rotating shaft 15. The plurality of flow-disturbing fan blades 17 drive the plurality of centrifugal fan blades 16 to rotate between the upper fan housing 12 and the lower fan housing 13 through the linkage rotating shaft 15. Since the upper fan housing 12, the lower fan housing 13 and the plurality of centrifugal fan blades 16 can be combined into a centrifugal fan, the plurality of centrifugal fan blades 16 can inhale a part of the high-temperature mixed gas into the flue gas-ammonia mixture collection box 10 through rotation and introduce the high-temperature mixed gas inhaled into the flue gas-ammonia mixture collection box 10 into the heat exchange component through the high-temperature diversion pipe 18, thereby realizing the recycling of the high-temperature flue gas.

[0038] In addition, the high-temperature mixed gas between the smoke-ammonia mixed gas collection tank 10 and the catalytic device 34 is introduced through the turbulence through-holes 11, and vortices are generated between the smoke-ammonia mixed gas collection tank 10 and the catalytic device 34 under the rotation and agitation of the multiple linkage rotating shafts 15. This can not only fully mix the flue gas, ammonia, and the combination of ammonia and air, but also increase the reaction path length of the combination of flue gas, ammonia, and air. At the same time, the mixed gas that has not participated in the recycling and the mixed gas led back from the inside of the smoke-ammonia mixed gas recycling assembly are remixed, enabling the combination of flue gas, ammonia, and air to be fully mixed, improving the mixing uniformity, and thus enhancing the denitration efficiency.

[0039] Such as Figures 7-9As shown in the figure, the heat exchange component includes a rear sealing plate 21, fixed heat conducting fins 22, an outer sealing cylinder 24, a front sealing plate 26, movable heat conducting fins 27, and movable heat exchange holes 28. One end of the high-temperature diversion pipe 18 far from the ammonia-nitrogen mixed gas collection box 10 is externally connected with a connecting clamping ring 19. The front end of the connecting clamping ring 19 is externally sleeved with a connecting clamping head 20, and a high-temperature resistant rubber sealing ring is arranged between the connecting clamping ring 19 and the connecting clamping head 20. The outer side of the front end of the connecting clamping head 20 is connected with the rear sealing plate 21. The front end of the rear sealing plate 21 is connected with a plurality of fixed heat conducting fins 22, and the plurality of fixed heat conducting fins 22 are rotationally symmetrically arranged around the central axis of the rear sealing plate 21. Fixed heat exchange holes 23 penetrate through the plurality of fixed heat conducting fins 22 from front to back, and the plurality of fixed heat exchange holes 23 are all opened at the rear end of the rear sealing plate 21. An outer sealing cylinder 24 is arranged outside the plurality of fixed heat conducting fins 22, and the outer sealing cylinder 24 is connected to the outer side of the front end of the rear sealing plate 21. The rear side of the upper end of the outer sealing cylinder 24 is communicated with a low-temperature return pipe 25. The other end of the low-temperature return pipe 25 is communicated with the upper side of the front end of the denitration tower 1, and the connection part is located between the ammonia-nitrogen mixed gas collection box 10 and the catalytic device 34. The center of the front end of the plurality of fixed heat conducting fins 22 is provided with a front sealing plate 26. The rear end of the front sealing plate 26 is connected with a plurality of movable heat conducting fins 27, and the plurality of movable heat conducting fins 27 are rotationally symmetrically arranged around the central axis of the front sealing plate 26. Movable heat exchange holes 28 are opened in the plurality of movable heat conducting fins 27, and the plurality of movable heat conducting fins 27 are sleeved outside the plurality of fixed heat conducting fins 22 through the plurality of movable heat exchange holes 28. High-temperature resistant rubber sealing rings are arranged between the plurality of movable heat conducting fins 27 and the plurality of fixed heat conducting fins 22, and the plurality of movable heat conducting fins 27 are all located in front of the low-temperature return pipe 25. The plurality of movable heat exchange holes 28 are all opened at the front end of the front sealing plate 26. An inner sealing cylinder 29 is arranged outside the plurality of movable heat conducting fins 27, and the inner sealing cylinder 29 is connected to the outside of the rear end of the front sealing plate 26 and is clamped inside the outer sealing cylinder 24. A high-temperature resistant rubber sealing ring is arranged between the inner sealing cylinder 29 and the outer sealing cylinder 24. During the process of preheating the flue gas inside the flue gas duct 2, the plurality of movable heat conducting fins 27 are sleeved outside the plurality of fixed heat conducting fins 22 through the plurality of movable heat exchange holes 28, and the front and rear ends of the plurality of fixed heat conducting fins 22 and the plurality of movable heat conducting fins 27 are sealed by the rear sealing plate 21 and the front sealing plate 26. Then, the plurality of fixed heat conducting fins 22 and the plurality of movable heat conducting fins 27 are externally sealed by the outer sealing cylinder 24 and the inner sealing cylinder 29, so that the rear sealing plate 21, the plurality of fixed heat conducting fins 22, the outer sealing cylinder 24, the plurality of movable heat conducting fins 27, and the inner sealing cylinder 29 form a heat exchange box that is airtight with the inside of the flue gas duct 2. At this time, the high-temperature mixed gas is introduced into the heat exchange box by the high-temperature diversion pipe 18, and heat exchange is carried out with the flue gas inside the flue gas duct 2 when flowing through the inside of the heat exchange box, realizing heat cycle utilization.

[0040] Among them, the high-temperature mixed gas flows outward from the center of the heat exchange box through the gaps between the multiple fixed heat conduction fins 22 and the gaps between the multiple moving heat conduction fins 27, and is blocked and collected on the outside by the outer sealing cylinder 24 and the inner sealing cylinder 29. Finally, it is led back into the denitration tower 1 through the low-temperature return pipe 25. During this process, the flue gas inside the flue gas pipeline 2 flows through the inside of the heat exchange box from front to back through the fixed heat exchange holes 23 and the moving heat exchange holes 28, and exchanges heat with the high-temperature mixed gas inside the heat exchange box through the inner walls of the fixed heat exchange holes 23 and the moving heat exchange holes 28, thereby preheating the flue gas inside the flue gas pipeline 2.

[0041] As Figure 3 and Figure 7 shown, at the opening at one end of the high-temperature diversion pipe 18 away from the flue gas-ammonia mixture collection box 10, a through-support frame 30 is connected inside. A positioning sliding rod 31 passes through the center of the through-support frame 30 from front to back and is slidably connected to the positioning sliding rod 31. The front end of the positioning sliding rod 31 is connected to the center of the rear end of the front sealing plate 26. The rear end of the positioning sliding rod 31 is connected to a spring compression plate 32, and the spring compression plate 32 is located at the rear side of the through-support frame 30. A positioning spring 33 is arranged between the through-support frame 30 and the spring compression plate 32. During the heat exchange process between the heat exchange box and the flue gas inside the flue gas pipeline 2, when the high-temperature mixed gas is introduced into the heat exchange box, the air pressure inside the heat exchange box increases, causing the moving heat conduction fin 27 to slide forward outside the fixed heat conduction fin 22, and driving the spring compression plate 32 to compress the positioning spring 33 through the front sealing plate 26 and the positioning sliding rod 31. The positioning spring 33 reaches equilibrium with the air pressure inside the heat exchange box through deformation and the support of the through-support frame 30, and when the air pressure inside the heat exchange box changes, it reaches equilibrium with the air pressure inside the heat exchange box again through deformation, thereby adjusting the overall length of the heat exchange box to adapt to the change in the flue gas flow rate.

[0042] At this time, when the air extraction speed of the air extractor set at the front end of the smoke extraction pipe 2 and the rear end of the smoke exhaust pipe 3 increases, the flow rate of the flue gas introduced into the denitration tower 1 increases. At the same time, the flow rate of the gas introduced into the gas coil 4 through the gas connection pipe 5 increases, ensuring that the temperature inside the denitration tower 1 meets the temperature required for the denitration reaction. At this time, the flow rate of the high-temperature mixed gas passing through the turbulence through-hole 11 increases, causing the rotation speed of the multiple linkage rotating shafts 15 driven by the high-temperature mixed gas to increase, and the amount of the high-temperature mixed gas inhaled by the flue gas-ammonia mixture collection box 10 to increase. As a result, the air pressure of the high-temperature mixed gas introduced into the heat exchange box increases. Under the action of the high air pressure, the moving heat conduction sheet 27 and the inner layer sealing cylinder 29 slide forward outside the fixed heat conduction sheet 22 and inside the outer layer sealing cylinder 24 respectively. Thus, the front-back length of the heat exchange box increases, and the overall length of the inner walls of the fixed heat exchange holes 23 and the moving heat exchange holes 28 increases in the front-back direction, thereby improving the heat exchange efficiency of the heat exchange box, improving the preheating efficiency of the flue gas inside the smoke extraction pipe 2, ensuring that the flue gas can be preheated in time, and ensuring that the efficiency of the denitration reaction is not affected by the flue gas flow rate.

[0043] On the contrary, when the air extraction speed of the air extractor set at the front end of the smoke extraction pipe 2 and the rear end of the smoke exhaust pipe 3 decreases, the flow rate of the flue gas introduced into the denitration tower 1 decreases. At the same time, the flow rate of the gas introduced into the gas coil 4 through the gas connection pipe 5 decreases, the amount of the high-temperature mixed gas inhaled into the flue gas-ammonia mixture collection box 10 decreases, and the air pressure inside the heat exchange box decreases. Under the action of the position adjustment spring 33, the moving heat conduction sheet 27 slides backward, shortening the front-back length of the heat exchange box and shortening the overall length of the inner walls of the fixed heat exchange holes 23 and the moving heat exchange holes 28 in the front-back direction, reducing the heat exchange efficiency of the heat exchange box, and preventing the preheating temperature of the flue gas inside the smoke extraction pipe 2 from being too high, which may lead to a decrease in the denitration reaction efficiency inside the denitration tower 1, and ensuring that the efficiency of the denitration reaction is not affected by the flue gas flow rate.

[0044] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A flue gas heating device for the denitration inlet flue, characterized in that, It includes a denitration tower (1). A smoke guiding pipe (2) is connected to the lower side of the front end of the denitration tower (1). A heat exchange component is arranged on the side close to the denitration tower (1) inside the smoke guiding pipe (2). A smoke exhaust pipe (3) is connected to the upper end of the denitration tower (1). A catalytic device (34) is arranged on the upper side inside the denitration tower (1). A gas coil pipe (4) is arranged on the lower side inside the denitration tower (1), and the gas coil pipe (4) is located below the connection between the smoke guiding pipe (2) and the denitration tower (1). The rear end of the gas coil pipe (4) is connected to a gas connection pipe (5), and the rear end of the gas connection pipe (5) penetrates outside the rear end of the denitration tower (1). The upper end of the gas coil pipe (4) is connected to a plurality of gas burners (6) with upward openings. A denitration agent coil pipe (7) is arranged in the middle inside the denitration tower (1), and the denitration agent coil pipe (7) is located below the catalytic device (34). The rear end of the denitration agent coil pipe (7) is connected to a denitration agent connection pipe (8), and the rear end of the denitration agent connection pipe (8) penetrates outside the rear end of the denitration tower (1). The lower end of the denitration agent coil pipe (7) is connected to a plurality of denitration agent spray nozzles (9) with downward openings. A flue gas-ammonia mixture circulation component is arranged between the denitration agent coil pipe (7) and the catalytic device (34).

2. The denitration inlet flue gas heating device according to claim 1, wherein The flue gas-ammonia mixture circulation component includes a flue gas-ammonia mixture collection box (10), turbulent flow holes (11), centrifugal fan blades (16) and turbulent flow fan blades (17). A flue gas-ammonia mixture collection box (10) is arranged above the denitration agent coil pipe (7). A plurality of turbulent flow holes (11) penetrate through the upper and lower parts inside the flue gas-ammonia mixture collection box (10). A plurality of fan upper shells (12) are connected to the inner wall of the upper end of the flue gas-ammonia mixture collection box (10), and the plurality of fan upper shells (12) are respectively located at the upper openings of the plurality of turbulent flow holes (11) and are coaxial with the plurality of turbulent flow holes (11).

3. The denitration inlet flue gas heating device according to claim 2, wherein, A plurality of fan lower shells (13) are connected to the inner wall of the lower end of the flue gas-ammonia mixture collection box (10), and the plurality of fan lower shells (13) are respectively located at the lower openings of the plurality of turbulent flow holes (11) and are coaxial with the plurality of fan upper shells (12). The plurality of fan lower shells (13) are respectively located below the outside of the plurality of fan upper shells (12). The inner lower ends of the plurality of fan upper shells (12) are all connected with rotating shaft frames (14). The central parts of the plurality of rotating shaft frames (14) all penetrate through a linkage rotating shaft (15) up and down.

4. The flue gas heating device for the denitrification inlet flue as described in claim 3, characterized in that The linkage rotating shaft (15) is rotatably connected inside the rotating shaft frame (14). A plurality of centrifugal fan blades (16) arranged in an "L" shape are connected to the lower side of the outside of the linkage rotating shaft (15), and the plurality of centrifugal fan blades (16) are all rotatably connected inside the lower ends of the turbulent flow holes (11) and are rotatably connected between the fan upper shell (12) and the fan lower shell (13). A plurality of turbulent flow fan blades (17) are connected to the upper side of the outside of the linkage rotating shaft (15), and the plurality of turbulent flow fan blades (17) are all rotatably connected inside the upper ends of the turbulent flow holes (11).

5. The denitration inlet flue gas heating device according to claim 4, characterized in that, The heat exchange assembly includes a rear sealing plate (21), a fixed heat conducting plate (22), an outer sealing cylinder (24), a front sealing plate (26), a dynamic heat conducting plate (27) and a dynamic heat exchange hole (28); the front end of the smoke and ammonia mixed gas collection box (10) is connected to a high-temperature guide pipe (18), and the other end of the high-temperature guide pipe (18) passes through the outside of the front end of the denitrification tower (1), and passes through the upper end of the smoke duct (2) and extends to the inside of the smoke duct (2); the high-temperature guide pipe (18) is connected to the outside of one end away from the smoke and ammonia mixed gas collection box (10) with a connecting clamp (19).

6. The flue gas heating device for the denitration inlet flue as described in claim 5, characterized in that, The front end of the connecting clamp (19) is sleeved with a connecting clamp (20), and a high-temperature resistant rubber sealing ring is provided between the connecting clamp (20). The front end of the connecting clamp (20) is connected to a rear sealing plate (21). The front end of the rear sealing plate (21) is connected to a plurality of fixed heat conducting plates (22), and the plurality of fixed heat conducting plates (22) are arranged in rotational symmetry around the central axis of the rear sealing plate (21).

7. The flue gas heating device for the denitrification inlet flue as described in claim 6, characterized in that, The fixed heat exchange holes (23) are all passed through the interior of the plurality of fixed heat conducting plates (22) from front to back, and the plurality of fixed heat exchange holes (23) are all opened at the rear end of the rear sealing plate (21). The outer sealing cylinder (24) is provided on the outside of the plurality of fixed heat conducting plates (22), and the outer sealing cylinder (24) is connected to the outer side of the front end of the rear sealing plate (21). The rear side of the upper end of the outer sealing cylinder (24) is connected to a low-temperature return pipe (25), and the other end of the low-temperature return pipe (25) is connected to the upper side of the front end of the denitrification tower (1), and the connection point is located between the smoke and ammonia mixed gas collection box (10) and the catalytic device (34). A front sealing plate (26) is provided at the center of the front end of the plurality of fixed heat conducting plates (22).

8. The denitration inlet flue gas heating device according to claim 7, wherein, The rear end of the front sealing plate (26) is connected to a plurality of dynamic heat conducting plates (27), and the plurality of dynamic heat conducting plates (27) are arranged in rotational symmetry around the central axis of the front sealing plate (26), and the plurality of dynamic heat conducting plates (27) are provided with dynamic heat exchange holes (28) inside, and are sleeved on the outside of the plurality of fixed heat conducting plates (22) through the plurality of dynamic heat exchange holes (28), and high-temperature resistant rubber sealing rings are provided between the plurality of dynamic heat conducting plates (27) and the plurality of fixed heat conducting plates (22), and the plurality of dynamic heat conducting plates (27) are located in front of the low-temperature return pipe (25).

9. The denitration inlet flue gas heating device according to claim 8, characterized in that, The plurality of dynamic heat exchange holes (28) are all opened at the front end of the front sealing plate (26), and an inner sealing tube (29) is provided outside the plurality of dynamic heat conducting plates (27), and the inner sealing tube (29) is connected to the outside of the rear end of the front sealing plate (26) and is clamped inside the outer sealing tube (24), and a high-temperature resistant rubber sealing ring is provided between the inner sealing tube (29) and the outer sealing tube (24).

10. A flue gas heating device for the denitrification inlet flue, as described in claim 9, characterized in that, At one end of the high-temperature diversion pipe (18) away from the flue gas-ammonia mixture collection box (10), a connection is provided inside the opening. A positioning slide rod (31) passes through the center of the support frame (30) from front to back and is slidably connected to the positioning slide rod (31). The front end of the positioning slide rod (31) is connected to the center of the rear end of the front sealing plate (26). The rear end of the positioning slide rod (31) is connected to a spring compression plate (32), and the spring compression plate (32) is located at the rear side of the support frame (30). A positioning spring (33) is provided between the support frame (30) and the spring compression plate (32).

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