Flue gas SCR (selective catalytic reduction) denitration and dust removal system of whole-bundle straw combustion and gasification equipment

Abstract

The invention belongs to the technical field of SCR denitration and dust removal, and particularly relates to a whole-bundle straw combustion gasification equipment flue gas SCR denitration and dust removal system which comprises a purification box body, and the purification box body is connected into a boiler through a gas inlet flue and a gas outlet flue; a plurality of purification layers are arranged in the purification box body in the vertical direction, each purification layer comprises a fixing frame, mounting grooves are uniformly formed in the fixing frames, a catalyst is embedded and mounted in the mounting grooves, the catalyst is of a square block structure, and honeycomb-shaped straight-through air channels are uniformly formed in the upper surface of the catalyst; the air outlet and the dust suction port are formed in the top of the mounting groove, the inner wall, especially the top opening area, of the straight-through air channel is fully cleaned through airflow scouring and differential pressure air suction effects, the cleaning efficiency is improved, the passing ability of a catalyst is guaranteed, and follow-up flue gas purification operation is promoted to be smoothly carried out.

Description

Technical Field

[0001] The present invention belongs to the technical field of SCR denitration and dust removal, and specifically relates to an SCR denitration and dust removal system for the flue gas of a whole-bale straw combustion and gasification device. Background Art

[0002] Domestic biomass power plants generally adopt in-furnace SNCR denitration, and the denitration efficiency is relatively low. Especially for circulating fluidized bed boilers, the designed furnace temperature is basically around 750 °C, which cannot reach the optimal temperature range of 850 - 1050 °C for SNCR denitration, resulting in the inapplicability of SNCR denitration in many projects and the inability to meet the ultra-low emission requirements.

[0003] Therefore, many biomass power plants adopt oxygen-depleted combustion to control the NOx emissions of boilers, resulting in insufficient combustion of biomass boilers and a particularly high CO concentration in the flue gas, which has a greater impact on the efficiency of biomass boilers. Even so, it is difficult for the NOx emissions of boilers to meet the ultra-low emission requirements.

[0004] At present, the most mature and reliable ultra-low emission denitration technology can only adopt SCR denitration technology, which is mainly divided into two technical routes: low-temperature SCR denitration and medium-high temperature SCR denitration.

[0005] The reaction temperature of the low-temperature SCR catalyst is usually around 200 °C, and it is arranged behind the bag filter, which can effectively avoid the alkali metal poisoning problem of the low-temperature SCR catalyst. However, the low-temperature SCR catalyst has very poor resistance to sulfur poisoning and tar poisoning. Especially, the flue gas after biomass fuel combustion contains a large amount of tar, and the tar will condense on the surface of the low-temperature SCR catalyst, easily causing the poisoning of the low-temperature SCR catalyst, and there are few application achievements in biomass power plants.

[0006] The medium-high temperature SCR reaction temperature is generally 280 - 420 °C, the cost of the SCR catalyst is relatively low and it is not easily sulfur-poisoned, and there are many application achievements in the biomass industry; When it is applicable to the purification treatment of the flue gas generated by biomass boilers, through long-term investigation and research, it is found that the main factors affecting the stable and efficient operation of SCR denitration are that the particulate impurities contained in the flue gas accumulate in the pores of the catalyst, causing the blockage of the catalyst and affecting the gas permeability of the flue gas. And it is necessary to stop the purification operation and open the equipment for manual cleaning, which affects the purification efficiency of the flue gas. Summary of the Invention

[0007] In order to make up for the deficiencies of the prior art and solve the above technical problems, the present invention provides an SCR denitration and dust removal system for the flue gas of a whole-bale straw combustion and gasification device, including a purification box body, and the purification box body is connected to the boiler through an intake flue and an outlet flue; Inside the purification box body, a plurality of purification layers are arranged along the vertical direction. Each purification layer includes a fixed frame, and a plurality of installation grooves are evenly arranged on the fixed frame. A catalyst is embedded in each installation groove. The catalyst has a square block structure, and a honeycomb-shaped direct air passage is evenly arranged on the upper surface of the catalyst. At the upper side of the catalyst in the inner wall of the installation groove, an air outlet is horizontally arranged. The air outlet communicates with the soot blowing module on the fixed frame. At the position of the inner wall of the installation groove opposite to the air outlet, a dust suction port is arranged. The dust suction port communicates with a bag dust removal device outside through a dust discharge pipe. A sonic soot blower is arranged below the purification layer, and the sonic soot blower is controlled by an external controller.

[0008] Preferably, the intake flue is communicated with the second-stage economizer of the boiler and is connected to the third-stage economizer of the boiler. And a group of light tube economizers are arranged at the position between the purification layer and the outlet flue at the bottom of the purification box body.

[0009] Preferably, side holes are evenly arranged on the side wall at the middle position in the vertical direction of the catalyst. The side holes horizontally extend through the catalyst to form a horizontal air passage.

[0010] Preferably, the soot blowing module includes a soot blowing cavity arranged on the side wall of the fixed frame. The soot blowing cavity communicates with a soot blowing fan, and the soot blowing cavity communicates with the air outlets on the side walls of each installation groove through a blowing air pipe. An air inflation hole is arranged at the position of the side wall of the soot blowing cavity opposite to the horizontal air passage. The air inflation hole communicates with the inside of the soot blowing cavity.

[0011] Preferably, a guide air pipe is arranged at the position of the inner wall of the fixed frame corresponding to the horizontal air passage. The guide air pipe horizontally penetrates through the horizontal air passages on the catalysts in the same row, and the end of the guide air pipe extends into the inside of the soot blowing cavity and communicates with the soot blowing cavity. Guide air holes are evenly arranged on the side wall of the guide air pipe; the cross section of the guide air pipe is smaller than the cross section of the side hole.

[0012] Preferably, the cross section of the guide air pipe is rectangular, and one end of one side of the guide air pipe is connected to the output end of a rotating device on the inner wall of the soot blowing cavity. The rotating device is controlled by an external controller.

[0013] Preferably, diversion blocks are arranged at both ends of the guide air pipe. The cross section of the diversion block is triangular.

[0014] Preferably, the guide air holes are distributed on the outer surface of the guide air pipe at the position between the two diversion blocks on both sides.

[0015] Preferably, an isolation filter screen is arranged at the position near the intake flue at the top of the purification box body. The isolation filter screen adopts a herringbone design.

[0016] Preferably, a temperature sensor is provided at the joint between the top of the purification box body and the intake flue, and an over-temperature emergency spraying system is provided above the purification layer.

[0017] The beneficial effects of the present invention are as follows: For the SCR denitrification and dust removal system of the flue gas of a whole-bale straw combustion gasification device described in the present invention, through the air outlet and the ash suction port provided at the top of the installation groove, the inner wall of the direct air duct, especially the top opening area, is fully cleaned through the air flow scouring and the differential pressure air suction effect, improving the cleaning efficiency, ensuring the passability of the catalyst, and promoting the smooth progress of the subsequent flue gas purification operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 is a perspective view of the present invention; Figure 2 is a schematic diagram of the internal structure of the purification box body of the present invention; Figure 3 is a perspective view of the fixing frame in the present invention; Figure 4 is a sectional view of the fixing frame in the present invention; Figure 5 is Figure 4 a partial enlarged view of part A in Figure 6 is a sectional view of the catalyst in the present invention; Figure 7 is Figure 6 a partial enlarged view of part B in

[0020] In the figure: purification box body 1, intake flue 11, outlet flue 12, purification layer 2, fixing frame 21, installation groove 22, air outlet 221, ash suction port 222, ash discharge pipe 223, soot blowing cavity 23, soot blowing pipe 231, inflation hole 232, rotating device 233, air guide pipe 24, air guide hole 241, diversion block 242, catalyst 3, direct air duct 31, side hole 32. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] 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. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1:

[0023] As shown in the accompanying drawings of the specificationFigures 1-7 As shown in the figure, a flue gas SCR denitration and dust removal system for a whole bale of straw combustion gasification equipment includes a purification box body 1, and the purification box body 1 is connected to a whole bale of straw combustion gasification boiler equipment through an intake flue 11 and an outlet flue 12; Inside the purification box body 1, a plurality of purification layers 2 are arranged vertically. The purification layer 2 includes a fixed frame 21, and installation grooves 22 are evenly arranged on the fixed frame 21. A catalyst 3 is embedded in the installation groove 22. The catalyst 3 has a square block structure, and honeycomb-shaped direct air channels 31 are evenly arranged on the upper surface of the catalyst 3; At the upper side of the catalyst 3 on the inner wall of the installation groove 22, an air outlet 221 is transversely arranged. The air outlet 221 communicates with a soot blowing module on the fixed frame 21. At the position of the inner wall of the installation groove 22 opposite to the air outlet 221, a dust suction port 222 is arranged. The dust suction port 222 communicates with an external bag dust removal device through a dust discharge pipe 223. A sonic soot blower is arranged below the purification layer 2, and the sonic soot blower is controlled by an external controller; The intake flue 11 communicates with the second-stage economizer of the boiler, and the intake flue 11 is connected to the third-stage economizer of the boiler. And a group of finned tube economizers are arranged at the position between the purification layer 2 and the outlet flue 12 at the bottom of the purification box body 1.

[0024] Specific working process: During the operation of a boiler using a whole bale of straw as a biomass fuel, in order to reduce pollutants such as nitrogen oxides and particulate dust in the combustion flue gas, the flue gas SCR denitration and dust removal system of the present application is arranged between the second-stage economizer and the third-stage economizer, so that the flue gas contacts the catalyst 3, and the nitrogen and oxygen pollutants in the flue gas are formed into nitrogen and water under the catalytic reduction effect, reducing the pollution to the atmospheric environment after flue gas emission; and the heat of the purified flue gas is fully collected through the third-stage economizer and the finned tube economizer; Specifically, in order to avoid the large amount of particulate dust contained in the flue gas from affecting the contact between nitrogen oxides and the catalyst 3, a large-particle isolation filter screen is arranged at the top of the purification box body 1 near the intake flue 11, and a herringbone design is adopted, so that the large-particle pollutants in the flue gas are intercepted above the isolation filter screen, reducing the particulate matter concentration in the flue gas contacting the catalyst 3; Furthermore, as the flue gas flows downward inside the purification box body 1, it will sequentially pass through multiple layers of purification layers 2. The square block-shaped catalysts 3 are evenly arranged inside the purification layer 2. After the flue gas flows downward and contacts the catalyst 3, it flows downward along the uniformly arranged direct air channels 31 on the catalyst 3. In this way, the flue gas is dispersed into uniform fine airflows, contacts the inner wall of the catalyst 3 in the direct air channels 31 and undergoes a reduction reaction of the catalyst 3, so that the nitrogen oxides in the flue gas are reduced to harmless substances such as nitrogen, thereby promoting the purification treatment of the pollutants in the flue gas; During the process of flue gas flowing into the catalyst 3, since the flow is blocked and diverted when initially contacting the top of the catalyst 3, the concentration of soot particle impurities in the flue gas is relatively high at this time, and the flue gas flow rate decreases. Therefore, the particulate impurities in the flue gas are easily adhered to the top surface of the catalyst 3 and the top inlet of the direct air passage 31. With the continuous accumulation of particulate impurities, it is particularly easy to cause blockage near the top opening in the direct air passage 31. Therefore, for each installation groove 22 of the catalyst 3, an air outlet 221 and an ash suction port 222 are respectively arranged at the upper side of the catalyst 3, and a corresponding sonic soot blower is arranged at the lower side of each catalyst 3, with the working end pointing to the bottom of the catalyst 3. In the intermittent period of flue gas purification, the input of flue gas is stopped, and the soot blowing module is started. The pressurized air flow is introduced into the air outlet 221 and then flows out horizontally, and is sucked into the ash suction port 222, and is guided to relevant treatment equipment such as a bag dust removal device outside through the connected ash discharge pipe 223. During this process, an air pump device is connected to the ash discharge pipe 223 to provide power support for sucking in the horizontally purified air flow. Because a horizontal impact air flow is formed in the upper side area of the catalyst 3 inside the installation groove 22, which scours the top surface of the catalyst 3 and takes away the particulate impurities adhered to the top surface of the catalyst 3, and because the horizontal air flow increases the air flow rate in the upper side area of the catalyst 3, the air pressure in the upper side area of the catalyst 3 decreases, prompting the air inside the direct air passage 31 of the catalyst 3 to flow upward, so that the area near the top opening of the direct air passage 31 is impacted by the reverse air flow, cleaning the particulate impurities adhered to the inner wall of the direct air passage 31. And for some direct air passages 31 that have poor flow or even blockage due to the accumulation of particulate impurities in the top opening area, the reverse air flow impact effectively dredges them, restoring the smooth flow of flue gas and enabling the normal flue gas purification function to be exerted. The sonic soot blower started simultaneously at the lower side position of the catalyst 3 releases air flow accompanied by impact sound waves, and the vibration impact prompts the impurities adhered to the inner wall of the catalyst 3 to loosen and fall off under the impact of the upward air flow. The downward air flow is supplemented into the direct air passage 31, and under the attraction of the upper side area of the catalyst 3, it continuously scours the inner wall of the direct air passage 31, especially the top opening area of the direct air passage 31. Finally, it drives the particulate impurities falling off from the catalyst 3 to merge into the horizontal air flow and enter the ash suction port 222, and flows to the external impurity cleaning equipment for treatment. In this way, the air outlet 221 and the ash suction port 222 arranged at the top position of the installation groove 22 in this application achieve sufficient cleaning of the inner wall of the direct air passage 31, especially the top opening area, through air flow scouring and differential pressure suction, improve the cleaning efficiency, ensure the passability of the catalyst 3, and promote the smooth progress of subsequent flue gas purification operations. Further, to avoid the problem of catalyst 3 failure caused by excessive temperature, a temperature sensor can be provided at the joint between the top of the purification box body 1 and the intake flue 11, and an existing over-temperature emergency spraying system is provided on the upper side of the purification layer 2. When it is detected that the temperature is too high, which may cause catalyst 3 failure and affect the normal waste gas purification treatment, the over-temperature emergency spraying system is activated to cool the flue gas and catalyst 3, which can effectively extend the service life of catalyst 3 and maintain the normal operation of the system of the present application.

[0025] Embodiment 2:

[0026] On the basis of Embodiment 1, side holes 32 are uniformly provided on the side wall at the middle position in the vertical direction of catalyst 3. The side holes 32 extend horizontally through catalyst 3 to form a horizontal air passage. The side holes 32 are circular hole structures, and the diameter is smaller than the width of the side wall of the corresponding straight air passage 31.

[0027] Specific working process: On the basis of the specific working process in Embodiment 1, considering that when the inside of the straight air passage 31 of catalyst 3 is blocked or the flow is not smooth, it will cause the flue gas to be difficult to enter the blocked straight air passage 31, resulting in the failure of the straight air passage 31 and the inability to play the role of purifying the flue gas normally; therefore, side holes 32 are provided on the side wall of catalyst 3 to form a horizontal air passage; in this way, after the flue gas flows into the straight air passage 31 and flows downward to the side holes 32 corresponding to the horizontal air passage, part of the flue gas will flow horizontally into the adjacent straight air passage 31, which slows down the vertical flow rate of the flue gas inside the straight-through flue, increases the residence time, and makes the catalytic reduction reaction more sufficient; And for the straight air passage 31 where the blockage position is above the horizontal air passage, the flue gas flowing in horizontally from the adjacent area will enter the blocked straight air passage 31 and flow out from the bottom opening, avoiding the blockage position and being used in the area below the blockage position in the straight-through flue to participate in the reduction and purification treatment of the flue gas; similarly, for the straight air passage 31 where the blockage position is below the horizontal air passage, after the flue gas flows in from the top and is blocked at the blockage position, it flows horizontally into the adjacent straight air passage 31 through the side holes 32 on the side wall, enabling the straight air passage 31 above the blockage position to participate in the purification treatment of the flue gas. In this way, even when the straight air passage 31 is blocked, the contact area between the flue gas and catalyst 3 can be effectively increased, and the utilization efficiency of catalyst 3 and the purification efficiency of the flue gas are improved, and the passageability of catalyst 3 to the flue gas is ensured.

[0028] Embodiment 3:

[0029] On the basis of Embodiment 2, there are various possible implementation schemes for the specific structure of the soot blowing module. Any technical solution that can satisfy the requirement of laterally releasing the pressurized flushing air flow from the air outlet 221 in each installation groove 22 can be applied to this application. In this embodiment, a possible technical solution is provided. Specifically, the soot blowing module includes a soot blowing chamber 23 provided on the side wall of the fixed frame 21. The soot blowing chamber 23 communicates with the soot blowing fan, and the soot blowing chamber 23 communicates with the air outlets 221 on the side walls of the respective installation grooves 22 through the soot blowing pipes 231; an air inflation hole 232 is provided at a position on the side wall of the soot blowing chamber 23 facing the side hole 32, and the air inflation hole 232 communicates with the inside of the soot blowing chamber 23.

[0030] Specific working process: On the basis of the specific working process in Embodiment 2, during the intermittent period of flue gas purification treatment, when it is necessary to clean the catalyst 3, the soot blowing fan is started. First, the outside air passes through the existing air filtration equipment at the air inlet end, is filtered and purified, and then pressurized and sent into the soot blowing chamber 23, so that the internal air pressure of the soot blowing chamber 23 increases; subsequently, the purified air flow accelerates along the interconnected soot blowing pipes 231 and flows into each air outlet 221, and then laterally flows out from the air outlet 221 and forms a lateral flushing air flow above the catalyst 3, thereby realizing the full cleaning of the top area of the catalyst 3 and ensuring the passability of the catalyst 3. Located in the middle area of the direct air passage 31, because it is far from the upper and lower openings, when the cleaning air flow formed by the external soot blowing equipment reaches the middle area, the kinetic energy is severely consumed, and the cleaning effect on the particulate impurities on the side wall of the middle area inside the direct air passage 31 is poor; therefore, in order to enable the inner wall of the direct air passage 31 to be more fully cleaned, an air inflation hole 232 is provided to connect the lateral air passage in the catalyst 3 to the soot blowing chamber 23. Open the control valve of the air inflation hole 232, so that the air flow inside the soot blowing chamber 23 flows out from the air inflation hole 232, passes through the side hole 32 and flows into the lateral air passage, and then enters each direct air passage 31 from the lateral flow passage respectively, so that the purified air flow participates in the flushing and cleaning of the direct air passage 31 from the inside to the outside and from the middle to the upper and lower sides. Regarding the problem of poor circulation due to impurity accumulation in some bottom opening areas, when the air flow directly flowing into the interior from the lateral air passage flows outwards, on the one hand, it can flow upwards and be accelerated to flush the top opening area under the drive of the lateral air flow above the catalyst 3; on the other hand, the air flow directly entering the middle area of the internal direct air passage 31 increases the air pressure in the middle area of the direct air passage 31, and because it is not weakened by the friction of the side wall of the direct air passage 31, it retains a large amount of kinetic energy. When flowing outwards and impacting, the particulate impurities accumulated on the inner wall of the middle area of the direct air passage 31, which are normally difficult to be effectively cleaned, are directly affected by the impact air flow and are discharged to the outside with the air flow, further ensuring the passability of the catalyst 3.

[0031] Embodiment 4:

[0032] On the basis of Embodiment 3, a gas guide pipe 24 is provided at a position on the inner wall of the fixed frame 21 corresponding to the transverse air duct. The gas guide pipe 24 horizontally penetrates the transverse air ducts on the same row of catalysts 3, and the end of the gas guide pipe 24 extends into the soot blowing chamber 23 and is provided with a control valve. The gas guide pipe 24 communicates with the soot blowing chamber 23, and air guide holes 241 are uniformly provided on the side wall of the gas guide pipe 24; the cross section of the gas guide pipe 24 is smaller than the cross section of the transverse air duct.

[0033] The cross section of the gas guide pipe 24 is rectangular, and one end of the gas guide pipe 24 is connected to the output end of the rotating device 233 on the inner wall of the soot blowing chamber 23. The rotating device 233 is controlled by an external controller; specifically, an external gear may be provided on the outer circle of the pipe orifice of the gas guide pipe 24 located inside the soot blowing chamber 23. The rotating device 233 is selected as a motor device, and the driving gear provided at the output end meshes with the external gear to realize indirect driving of the gas guide pipe 24 without affecting the air flow into the gas guide pipe 24.

[0034] Specific working process: On the basis of the specific working process in Embodiment 3, in order to expand the action range of the scouring air flow entering the transverse air duct from the inflation hole 232, a gas guide pipe 24 is provided so that the gas guide pipe 24 horizontally passes through the corresponding transverse air ducts on each catalyst 3; in this way, the scouring air flow is filled into the gas guide pipe 24, and then the scouring air flow is restricted through the gas guide pipe 24, so that it is concentrated along a stable flow trajectory and flows out from the air guide holes 241 uniformly provided on the side wall of the gas guide pipe 24, and is more uniformly distributed into the direct air duct 31 in the area far from the inflation hole 232, expanding the action range of the transverse scouring air flow; And a rotating device 233 is provided and connected to the gas guide pipe 24. When starting to rotate, the gas guide pipe 24 can be driven to rotate slowly. The rotating gas guide pipe 24 can clean the particulate impurities that may adhere to the inner wall of the transverse air duct, ensuring the smoothness of the transverse air duct; the centrifugal action of rotation can clean the particulate impurities adhering to the surface of the gas guide pipe 24, preventing the accumulation of particulate impurities on the surface of the gas guide pipe 24 and causing blockage of the direct air duct at the position of the gas guide pipe 24; Further, the cross section of the gas guide pipe 24 is set to a flat rectangular structure. When the flue gas flows, the two ends of the gas guide pipe 24 are controlled to be vertical, so that the horizontal projection is small and the obstruction to the downward flowing flue gas is small; when it is necessary to scour and clean the inner wall of the direct air duct 31, the rotating device 233 is controlled to rotate slowly; when the gas guide pipe 24 rotates to a horizontal state, at this time the horizontal projection area of the gas guide pipe 24 is large and the obstruction to the upward flowing air flow is large; through the setting of the controller, when the gas guide pipe 24 rotates to a vertical state, it is maintained for 3 - 5 s and then rotates to a horizontal state, and so on; When in the horizontal state, the airflow intercepted by the air guide pipe 24 is released in a short time when the air guide pipe 24 rotates to the vertical state, forming a short-time violent impact airflow. The airflow accelerates upward through the position of the air guide pipe 24, increasing the impact on the inner wall of the direct air passage 31, effectively dredging the blockage inside the direct air passage 31, so that the particulate impurities adhered to the inner wall of the direct air passage 31 are fully cleaned, ensuring the normal purification efficiency of the catalyst 3.

[0035] Embodiment Five:

[0036] On the basis of Embodiment Four, flow guiding blocks 242 are arranged at both end parts of the air guide pipe 24. The cross section of the flow guiding block 242 is triangular, and the air guide holes 241 are distributed on the outer surface of the air guide pipe 24 at the part between the two flow guiding blocks 242 on both sides; that is, when the air guide pipe 24 rotates to the vertical state, at this time, the flow guiding blocks 242 are located on the upper and lower sides of the air guide pipe 2, and the air guide holes 241 are located at the horizontal positions on both sides of the outer surface of the air guide pipe 2.

[0037] Specific working process: On the basis of the specific working process in Embodiment Four, when normally purifying flue gas, the air guide pipe 24 rotates to the vertical state. The flow guiding blocks 242 located on the upper and lower sides guide the vertically flowing airflow to the two side areas, increasing the contact degree between the flue gas and the inner wall of the direct air passage 31, and at the same time reducing the direct impact on the air guide pipe 24; At this time, the air flowing downward from both side surfaces of the air guide pipe 2 passes through the openings of the air guide holes 241 on both sides, causing a negative pressure at the openings of the air guide holes 241, making the air inside the air guide pipe 2 tend to flow outward, preventing particulate impurities in the flue gas from entering the inside of the air guide pipe 2, and further reducing the occurrence of blockage inside the air guide pipe 2.

[0038] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A flue gas SCR denitrification and dust removal system for a whole-bale straw combustion gasification device, comprising a purification box (1), wherein the purification box (1) is connected to a boiler through an air inlet flue (11) and an air outlet flue (12); Features: A plurality of purification layers (2) are arranged vertically inside the purification box (1), the purification layer (2) comprising a fixing frame (21), the fixing frame (21) being evenly provided with mounting grooves (22), a catalyst (3) being embedded and installed inside the mounting groove (22), the catalyst (3) being a block-shaped structure, and a honeycomb-shaped straight air passage (31) being evenly provided on the upper surface of the catalyst (3); An air outlet (221) is laterally arranged on the inner wall of the installation groove (22) at a position located on the upper side of the catalyst (3); the air outlet (221) is communicated with a soot blowing module on the fixed frame (21); an ash suction port (222) is arranged on the inner wall of the installation groove (22) directly opposite to the air outlet (221); the ash suction port (222) is communicated with an external bag dust removal device through an ash discharge pipe (223); a sonic soot blower is arranged on the lower side of the purification layer (2); the sonic soot blower is controlled by an external controller.

2. The flue gas SCR denitrification and dust removal system of a whole-bale straw combustion gasification equipment according to claim 1 is characterized by: The air inlet flue (11) is communicated with the second-stage economizer of the boiler, the air inlet flue (11) is connected to the third-stage economizer of the boiler, and a group of light tube economizers are arranged at the bottom of the purification box (1) between the purification layer (2) and the air outlet flue (12).

3. The flue gas SCR denitrification and dust removal system of a whole-bale straw combustion gasification equipment according to claim 1 is characterized by: Side holes (32) are evenly arranged on the side wall at the middle position in the vertical direction of the catalyst (3), and the side holes (32) extend transversely through the catalyst (3) to form a transverse air channel.

4. The flue gas SCR denitrification and dust removal system of a whole-bale straw combustion gasification equipment according to claim 3 is characterized by: The soot blowing module comprises a soot blowing chamber (23) arranged on the side wall of the fixing frame (21), the soot blowing chamber (23) is communicated with a soot blowing fan, and the soot blowing chamber (23) is communicated with an air outlet (221) on the side wall of each installation slot (22) through a blowing pipe (231); An air filling hole (232) is provided at a position of the side wall of the soot blowing chamber (23) facing the transverse air passage, and the air filling hole (232) is communicated with the interior of the soot blowing chamber (23).

5. The flue gas SCR denitrification and dust removal system of the whole-bale straw combustion gasification equipment according to claim 4 is characterized by: An air guide pipe (24) is arranged at a position of the inner wall of the fixed frame (21) corresponding to the transverse air channel. The air guide pipe (24) transversely penetrates the transverse air channel on the same row of catalysts (3), and the end of the air guide pipe (24) extends into the interior of the soot blowing chamber (23) and communicates with the soot blowing chamber (23). The side wall of the air guide pipe (24) is evenly provided with air guide holes (241); the cross section of the air guide pipe (24) is smaller than the cross section of the side hole (32).

6. The flue gas SCR denitrification and dust removal system of the whole straw bale combustion gasification equipment according to claim 5 is characterized by: The cross section of the air guide pipe (24) is rectangular, and one end of the air guide pipe (24) is connected to the output end of a rotating device (233) on the inner wall of the soot blowing chamber (23), and the rotating device (233) is controlled by an external controller.

7. The flue gas SCR denitrification and dust removal system of the whole straw bale combustion gasification equipment according to claim 6 is characterized by: Guide blocks (242) are provided at both side ends of the air guide pipe (24), and the cross section of the guide block (242) is triangular.

8. The flue gas SCR denitrification and dust removal system of a whole-bale straw combustion gasification equipment according to claim 7 is characterized by: The air guide holes (241) are distributed on the outer surface of the air guide pipe (24) at a location between the guide blocks (242) on both sides.

9. The flue gas SCR denitrification and dust removal system of a whole-bale straw combustion gasification equipment according to claim 1, characterized in that: An isolation filter is provided at the top of the purification box (1) near the air inlet flue (11), and the isolation filter adopts a herringbone design.

10. The flue gas SCR denitrification and dust removal system of a whole-bale straw combustion gasification equipment according to claim 1, characterized in that: A temperature sensor is provided at the junction of the top of the purification box (1) and the air inlet flue (11), and an over-temperature emergency spray system is provided on the upper side of the purification layer (2).

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