SCR (Selective Catalytic Reduction) denitration treatment system for boiler flue gas

Abstract

The invention relates to the technical field of fuel cell control, and particularly provides a boiler flue gas SCR (Selective Catalytic Reduction) denitration treatment system which comprises a boiler body, a boiler economizer, a dust removal device and an SCR reactor which are connected in sequence, the SCR reactor is used for carrying out denitration treatment on the flue gas through a catalyst; the catalyst in the SCR reactor meets the following conditions: the activity is more than or equal to 35m / h, the SO2 / SO3 conversion rate is less than or equal to 1%, and the resistance of a single-layer catalyst is less than 200Pa; the catalyst is a wide-temperature arsenic-resistant catalyst; a first flow guide frame body is arranged between the inlet end in the SCR reactor and the first operation layer, and is made of a high-temperature-resistant material with high thermal conductivity; the first flow guide frame body is a circular-truncated-cone-shaped net frame, the bottom face of the first flow guide frame body is provided with a plurality of heat conduction rings which are arranged in an overlapped mode, a plurality of heat conduction blades which are evenly distributed around the center of a circular truncated cone are arranged on the inner side of the side wall of the circular truncated cone of the first flow guide frame body, and the included angles between any two heat conduction blades are the same. The included angle between the side edge of any heat-conducting blade facing the center of the circular truncated cone and the center of the circular truncated cone is an acute angle. By adopting the mode, the service life of the catalyst can be prolonged when the arsenic-containing flue gas is treated.

Description

Technical Field

[0001] The present application relates to the technical field of boiler flue gas denitration treatment, and in particular to a boiler flue gas SCR denitration treatment system. Background Art

[0002] In order to meet the requirements of the latest national environmental protection standards, the flue gas of the 600MW coal-fired unit is treated by a selective catalytic reduction SCR denitrification reactor. The catalyst used in SCR is basically based on TiO2 as a carrier, V2O5 as the main active component, and WO3 and MoO3 as antioxidant and anti-poisoning auxiliary components. The catalyst is the core part of SCR technology and determines the denitrification efficiency and economy of the SCR system. The original catalyst was a metal catalyst such as Pt-Rh and Pt, with monolithic ceramics such as alumina as a carrier. It has the characteristics of high activity and low reaction temperature, but its high price limits its application in power plants.

[0003] At present, due to the high arsenic content in coal, combustion will accelerate the aging of the catalyst. Therefore, it is urgent to transform the flue gas denitrification treatment system in order to increase the service life of the catalyst while meeting environmental protection requirements. Summary of the invention

[0004] In view of the above problems, the present application provides a boiler flue gas SCR denitrification treatment system to increase the service life of the catalyst when treating arsenic-containing flue gas.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

[0006] In a first aspect, the present application provides a boiler flue gas SCR denitrification treatment system, comprising:

[0007] The invention comprises: a boiler body (1), a boiler economizer (2), a first pipeline (4), a dust removal device (3), a second pipeline (5), an SCR reactor (6) and a chimney (7) which are connected in sequence; the SCR reactor performs denitration treatment on flue gas by means of a catalyst; the reaction principle of the catalyst comprises a basic reaction part and a side reaction part, the basic reaction part comprises: 4NO+4NH3+O2→4N2+6H2O; 2NO2+4NH3+O2→3N2+6H2O; the side reaction part comprises: SO2+1 / 2O2→SO3; NH3+SO3+H2O→NH4HSO4; 2NH3+SO3+H2O→(NH4)2SO4; wherein:

[0008] The catalyst in the SCR reactor meets the following requirements: activity ≥ 35 m / h, SO2 / SO3 conversion rate ≤ 1%, and resistance of a single-layer catalyst < 200 Pa; the catalyst in the SCR reactor is a wide-temperature arsenic-resistant catalyst;

[0009] The catalyst in the SCR reactor is configured in the form of two operating layers and one standby layer; a first flow guide frame (60) is arranged between the inlet end of the SCR reactor and the first operating layer (61), and the first flow guide frame (60) is made of a material that is resistant to high temperatures and has high thermal conductivity;

[0010] The first flow guide frame (60) is a truncated cone-shaped grid frame. The bottom surface of the first flow guide frame (60) is a plurality of heat-conducting rings (601) arranged overlapping each other. The inner side of the truncated cone side wall of the first flow guide frame is provided with a plurality of heat-conducting blades (602) evenly distributed around the center of the truncated cone. The angle between any two heat-conducting blades (602) is the same, and the angle between the side edge of any heat-conducting blade facing the center of the truncated cone and the center of the truncated cone is an acute angle.

[0011] In a possible implementation, the catalyst is a plate catalyst or a honeycomb catalyst to which an arsenic-resistant element is added.

[0012] In a possible implementation, the honeycomb catalyst has 20 holes.

[0013] In a possible implementation, the metal that is resistant to high temperatures and has high thermal conductivity is a silicon-containing aluminum alloy or cubic boron nitride.

[0014] In a possible implementation, a second flow guide bracket may be provided between the first operating layer and the second operating layer. The flow guide bracket is mainly a cylindrical grid frame structure for dispersing heat, and heat conduction blades are evenly distributed on the inner wall along the circumference.

[0015] In a possible implementation, the dust removal device (3) comprises: a filter box (8), a sealing cover (9), a handle (10), an adsorption core (11), a bolt (12), a first mesh plate (14), a second mesh plate (16) and a connecting portion (17).

[0016] In a possible implementation, a connecting portion (17) is provided at the top of the filter box (8), the connecting portion (17) is communicated with the inside of the filter box (8), a sealing cover (9) is buckled at the top of the connecting portion (17), the sealing cover (9) is fixedly connected to the top of the connecting portion (17) by means of bolts (12), a handle (10) is fixedly connected at the center of the upper end surface of the sealing cover (9), an adsorption core (11) is fixedly connected at the center of the lower end surface of the sealing cover (9), a first mesh plate (14) and a second mesh plate (16) are movably plugged into the inside of the filter box (8), the first mesh plate (14) and the second mesh plate (16) are arranged relatively parallel, the upper parts of the first mesh plate (14) and the second mesh plate (16) are both snap-fitted to the top of the filter box (8), and the two ends of the lower end surface of the sealing cover (9) are in contact with the top of the first mesh plate (14) and the top of the second mesh plate (16), respectively.

[0017] In a possible implementation, the adsorption core (11) is located between a first mesh plate (14) and a second mesh plate (16); a first cavity (13) communicating with a first pipe (4) is provided inside the filter box (8) at one end close to the first mesh plate (14); a second cavity (15) communicating with a second pipe (5) is provided inside the filter box (8) at one end close to the second mesh plate (16); and a filter cavity (18) is provided in the center of the filter box (8).

[0018] In a possible implementation, the boiler body (1) is used to output flue gas, which is transported to a dust removal device (3) through a boiler economizer (2) and a first pipeline (4); the dust removal device (3) is used to remove dust from the flue gas, and the flue gas after dust removal is transported to an SCR reactor (6) through a second pipeline (5); the SCR reactor (6) is used to denitrate the flue gas through a catalyst, and the flue gas after denitrification is transported into a chimney (7) through a fan for discharge.

[0019] The boiler flue gas SCR denitration treatment system provided by the present application adds a first guide frame between the first operating layer and the inlet end of the second-stage catalyst in the SCR reactor. The guide frame is made of a material that is resistant to high temperatures and has high thermal conductivity. When the flue gas to be treated enters the SCR reactor, it is evenly distributed through the catalyst under the diversion effect of the heat-conducting blades on the inner wall of the guide frame. At this time, the arsenic element and heat in the flue gas are also evenly distributed through the catalyst, thereby making the arsenic poisoning degree of each part of the catalyst more uniform. At the same time, since the direction of the heat-conducting blades is in the same direction as the flue gas flow direction, the influence of the guide frame as a whole on the flow velocity in the SCR reactor can be ignored, thereby ensuring the original treatment efficiency of the catalyst. In addition, the heat-conducting ring at the bottom of the guide frame can also quickly disperse the heat located in the positive direction of the inlet end to the paving direction of the catalyst, thereby alleviating or avoiding the problem of uneven arsenic poisoning degree due to different temperatures in various parts of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present application and form a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application.

[0021] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0022] Figure 1 This is a schematic diagram of the structure of the boiler flue gas SCR denitrification treatment system for this application;

[0023] Figure 2 A top view of the structure of the first flow guide bracket of the present application;

[0024] Figure 3 This is a structural side view of the first flow guide bracket of the present application;

[0025] Figure 4 A schematic diagram of the bottom surface structure of the first flow guide bracket of the present application;

[0026] Figure 5 This is a schematic diagram of the structure of the dust removal device of this application.

[0027] In the figure: 1. boiler body; 2. boiler economizer; 3. dust removal device; 4. first pipeline; 5. second pipeline; 6. SCR reactor; 60. first guide bracket; 601. heat transfer ring; 602. heat transfer blade; 7. chimney; 8. filter box; 9. sealing cover; 10. handle; 11. adsorption core; 12. bolt; 13. first cavity; 14. first mesh plate; 15. second cavity; 16. second mesh plate; 17. connecting part; 18. filter cavity. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of this application, unless otherwise specified, "plurality" means two or more.

[0030] The detailed technical issues of the application scenarios of the SCR denitration treatment system provided in the embodiments of the present application are as follows:

[0031] The catalysts of the denitration reactor of the 2×600MW coal-fired power generation unit are arranged in 2+1, that is, 2 layers are in operation and 1 layer is in standby, and the catalyst adopts honeycomb type. In June 2017, the ultra-low emission transformation of Unit 2 was implemented, and a standby layer of catalyst was installed in the denitration system. In 2020, due to the decrease in the activity of the denitration catalyst, ammonia escape increased, causing blockage of the air preheater and dust hanging on the plates and pole wires of the electrostatic precipitator. During the graded maintenance, the catalyst transformation of the denitration system of boilers 1 and 2 was carried out, and the upper and middle layer catalysts were replaced with arsenic-resistant wide-temperature catalysts. The designed chemical life of the catalyst is 16,000 hours or 2 years after the first ammonia injection. The transformation of Unit 1 was completed on April 20, and the transformation of Unit 2 was completed on May 21. In 2021, the original honeycomb catalyst of the standby layer of boiler 1 was regenerated. The designed chemical life of the catalyst is 3 years or 24,000 hours, and the transformation was completed on May 5. As of June 2022, the arsenic-resistant wide-temperature catalysts installed in Units 1 and 2 in 2020 have reached their designed life span. According to tests by a third-party agency, the activity of each layer of catalysts in the two furnaces is as follows: the first, second and third layer catalyst activities of Furnace 1 are 21.1m / h, 26m / h and 18.8m / h, respectively; the first, second and third layer catalyst activities of Furnace 2 are 23.1m / h, 25.4m / h and 35.2m / h, respectively. The catalysts in the two furnaces are severely poisoned by arsenic, with the first, second and third layer catalysts of Furnace 1 being poisoned by 4.57%, 4.41% and 1.19%, respectively; the first, second and third layer catalysts of Furnace 2 being poisoned by 5.39%, 4.93% and 0%, respectively. By the maintenance period in 2023, the two furnaces will have The two layers of catalysts on the first furnace have been in operation for 3 years, exceeding the design life. The regenerated catalyst in the spare layer of boiler No. 1 has been used for 2 years. Due to arsenic poisoning, the activity decays rapidly. The manufacturer recommends replacing it when the activity is lower than 20m / h. According to the activity decay curve, the activity decreases by about 5-6m / h each year. At the same time, due to the high arsenic content in the coal burned by Yanshan Lake Power Generation Company, in order to ensure that the unit meets environmental emission standards, reduce production costs, and ensure safe equipment operation, it is necessary to transform the denitrification catalysts of boilers No. 1 and No. 2. Because the spare layer is a regenerated honeycomb catalyst, and it is severely arsenic-poisoned, the activity decays rapidly. The second layer is an arsenic-resistant plate catalyst with relatively high activity. It is planned to transform the first and third layers of catalysts of boiler No. 1 into arsenic-resistant wide-temperature ones, and the first layer of catalyst of boiler No. 2 into arsenic-resistant wide-temperature ones.

[0032] It can be seen that due to the high arsenic content in the coal, the uneven distribution of arsenic poisoning of the catalyst leads to severe local aging of the catalyst, affecting the overall service life of the catalyst.

[0033] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0034] As an embodiment of the present invention, Figure 1-5As shown, the present invention provides a boiler flue gas SCR denitrification treatment system, which includes a boiler body 1, a boiler economizer 2, a first pipeline 4, a dust removal device 3, a second pipeline 5, an SCR reactor 6 and a chimney 7 connected in sequence.

[0035] In the embodiment of the present application, the SCR reactor performs denitration treatment on the flue gas through a catalyst; the reaction principle of the catalyst includes a basic reaction part and a side reaction part, and the basic reaction part includes:

[0036] 4NO+4NH3+O2→4N2+6H2O;

[0037] 2NO2+4NH3+O2→3N2+6H2O;

[0038] The side reaction part includes:

[0039] SO2+1 / 2O2→SO3;

[0040] NH3+SO3+H2O→NH4HSO4;

[0041] 2NH3+SO3+H2O→(NH4)2SO4;

[0042] In the embodiment of the present application, the catalyst in the SCR reactor meets the following requirements: activity ≥ 35 m / h, SO2 / SO3 conversion rate ≤ 1%, and single-layer catalyst resistance < 200 Pa; the catalyst in the SCR reactor is a wide temperature arsenic-resistant catalyst; it is used to achieve a denitrification efficiency of more than 90% and meet the outlet NOx concentration standard of 50 mg / Nm3 (ammonia slip is less than 3 ppm).

[0043] In the embodiment of the present application, the catalyst in the SCR reactor is configured in the form of two operating layers and one standby layer; a first flow guide frame 60 is provided between the inlet end of the SCR reactor and the first operating layer.

[0044] In the embodiment of the present application, the first flow guide frame 60 is made of a material that is resistant to high temperatures and has high thermal conductivity.

[0045] In the embodiments of this application, reference may be made to Figure 2-4 As an example, the first flow guide frame 60 is a truncated cone-shaped grid frame, the bottom surface of the first flow guide frame 60 is a plurality of heat-conducting rings 601 arranged overlapping each other, the inner side of the truncated cone side wall of the first flow guide frame is provided with a plurality of heat-conducting blades 602 evenly distributed around the center of the truncated cone, the angles between any two heat-conducting blades 602 are the same, and the angle between the side edge of any heat-conducting blade facing the center of the truncated cone and the center of the truncated cone is an acute angle.

[0046] For reference Figure 3, the projection area of ​​the top of the truncated cone on the bottom surface is smaller than the projection area of ​​the lower end point of the heat conducting blade on the bottom surface.

[0047] The boiler flue gas SCR denitration treatment system provided by the present application adds a first guide frame between the first operating layer and the inlet end of the second-stage catalyst in the SCR reactor. The guide frame is made of a material that is resistant to high temperatures and has high thermal conductivity. When the flue gas to be treated enters the SCR reactor, it is evenly distributed through the catalyst under the diversion effect of the heat-conducting blades on the inner wall of the guide frame. At this time, the arsenic element and heat in the flue gas are also evenly distributed through the catalyst, thereby making the arsenic poisoning degree of each part of the catalyst more uniform. At the same time, since the direction of the heat-conducting blades is in the same direction as the flue gas flow direction, the influence of the guide frame as a whole on the flow velocity in the SCR reactor can be ignored, thereby ensuring the original treatment efficiency of the catalyst. In addition, the heat-conducting ring at the bottom of the guide frame can also quickly disperse the heat located in the positive direction of the inlet end to the paving direction of the catalyst, thereby alleviating or avoiding the problem of uneven arsenic poisoning degree due to different temperatures in various parts of the catalyst.

[0048] In the embodiment of the present application, the catalyst is a plate catalyst or a honeycomb catalyst to which an arsenic-resistant element is added.

[0049] It should be noted that the current SCR catalysts are basically based on TiO2 as a carrier, V2O5 as the main active ingredient, and WO3 and MoO3 as antioxidant and anti-poisoning auxiliary ingredients. The components of this type of catalyst are mainly composed of metal oxides such as V2O5 (WO3), Fe2O3, CuO, CrOx, MnOx, MgO, MoO3, NiO, or a mixture that acts in combination. It usually uses TiO2, Al2O3, ZrO2, SiO2, activated carbon (AC), etc. as carriers, and undergoes reduction reactions with reducing agents such as liquid ammonia or urea in the SCR system. It has become the mainstream catalyst product for SCR denitrification engineering applications in power plants. Catalyst types can be divided into three types: plate type, honeycomb type, and corrugated plate type. Among them, the plate catalyst uses a metal mesh pressed from a stainless steel metal plate as the substrate, and a mixture of TiO2, V2O5, etc. is adhered to the stainless steel mesh. After pressing and calcining, the catalyst plate is assembled into a catalyst module. Honeycomb catalysts are generally homogeneous catalysts. A mixture of TiO2, V2O5, WO3, etc. is made into catalyst elements with a cross-section of 150mmX150mm and different lengths through a ceramic extrusion device, and then assembled into a standard module with a cross-section of about 2m*1m. The manufacturing process of corrugated plate catalysts generally uses TiO2 reinforced with glass fiber as the substrate, and impregnates active ingredients such as WO3 and V2O5 into the surface of the catalyst to achieve the purpose of improving the catalyst activity and reducing the SO2 oxidation rate. The design of the catalyst is to select a catalyst with a certain reaction area, a certain arsenic resistance, and a certain strength to meet the design requirements of the basic SCR performance such as denitrification efficiency and ammonia escape rate under the flue gas flow, temperature, pressure, and composition conditions at the economizer outlet. The plate-type wide-temperature arsenic-resistant catalyst selected this time has wide temperature, arsenic poisoning resistance and anti-collapse performance. The outlet NOx concentration meets the standard of 50mg / Nm3 (ammonia slip is less than 3ppm), and the flue gas temperature is not higher than 290-425℃ for long-term operation. At the same time, the catalyst should be able to withstand the test of operating temperature of 450℃ for not less than 5 hours without any damage. Ammonia slip meets the design requirement of <2.5ppm, which can reduce the corrosion of ammonia slip on the air preheater and electrostatic precipitator and improve the safety and reliability of boiler operation. Exemplarily, the honeycomb catalyst is a 20-hole honeycomb catalyst.

[0050] In the embodiments of the present application, arsenic-resistant elements are added to the catalyst components, and the catalyst components can maintain activity during their service life when the arsenic content of the coal is 65 μg / g.

[0051] In the embodiment of the present application, the processing process of the system includes:

[0052] S1. Prepare boiler flue gas treatment SCR denitrification system;

[0053] S2, the flue gas output by the boiler body 1 passes through the boiler economizer 2 and the first pipeline 4 to enter the dust removal device 3 for dust removal. The dust-removed flue gas is sent to the SCR reactor 6 through the second pipeline 5 to denitrate the flue gas through the catalyst. The flue gas after denitrification is sent to the chimney 7 through the fan for discharge.

[0054] The present invention also includes that the catalyst is a 20-hole honeycomb catalyst, anti-arsenic elements are added to the catalyst, the catalyst can meet the outlet NOx concentration standard of less than 50 mg / Nm3 (ammonia slip is less than 3 ppm), and can operate for a long time when the flue gas temperature is not higher than 290-425°C. At the same time, the catalyst can withstand the test of an operating temperature of 450°C for not less than 5 hours without damage to the catalyst.

[0055] SCR flue gas denitrification principle of SCR reactor 6: SCR flue gas denitrification technology is to selectively react NOx in flue gas to generate nitrogen and water that are harmless to the environment by using a reduction catalyst under the action of a catalyst within the flue gas temperature range of 300-420°C. The reducing agent is generally a hydrocarbon, and ammonia is widely used. NOx in coal-fired flue gas is mainly NO. In the absence of a catalyst, NOx and NH3 can also react chemically, but only within a relatively narrow temperature range, generally around 930°C. By selecting a suitable catalyst, the reaction temperature can be effectively reduced and the reaction rate can be increased.

[0056] As an embodiment of the present invention, Figure 1 , Figure 5 As shown, the present invention also provides a boiler flue gas SCR denitration treatment system, including a boiler body 1, a boiler economizer 2, a dust removal device 3, a first pipeline 4, a second pipeline 5, an SCR reactor 6 and a chimney 7;

[0057] The dust removal device 3 includes a filter box 8 , a sealing cover 9 , a handle 10 , an adsorption core 11 , a bolt 12 , a first mesh plate 14 , a second mesh plate 16 and a connecting portion 17 .

[0058] The present invention also includes that a connecting portion 17 is provided at the top of the filter box 8, the connecting portion 17 is communicated with the inside of the filter box 8, a sealing cover 9 is buckled at the top of the connecting portion 17, the sealing cover 9 is fixedly connected to the top of the connecting portion 17 by a bolt 12, a handle 10 is fixedly connected at the center of the upper end surface of the sealing cover 9, an adsorption core 11 is fixedly connected at the center of the lower end surface of the sealing cover 9, a first mesh plate 14 and a second mesh plate 16 are movably inserted inside the filter box 8, the first mesh plate 14 and the second mesh plate 16 are relatively parallelly arranged, the upper parts of the first mesh plate 14 and the second mesh plate 16 are both snap-fitted with the top of the filter box 8, and the two ends of the lower end surface of the sealing cover 9 are in contact with the top of the first mesh plate 14 and the second mesh plate 16 respectively.

[0059] The present invention also includes that the adsorption core 11 is located between the first mesh plate 14 and the second mesh plate 16, the filter box 8 is provided with a first cavity 13 connected to the first pipe 4 at one end close to the first mesh plate 14, the filter box 8 is provided with a second cavity 15 connected to the second pipe 5 at one end close to the second mesh plate 16, a filter cavity 18 is provided in the center of the filter box 8, and the mesh diameter of the first mesh plate 14 is larger than the mesh diameter of the second mesh plate 16.

[0060] When the present invention is in use, the flue gas output by the boiler body 1 passes through the boiler economizer 2 and the first pipeline 4 to enter the dust removal device 3 for dust removal, and the dust-removed flue gas is sent to the SCR reactor 6 through the second pipeline 5 to denitrate the flue gas through the catalyst, and the flue gas after denitrification is sent to the chimney 7 through the fan for discharge, and the catalyst is a 20-hole honeycomb catalyst, and the catalyst is added with arsenic-resistant elements;

[0061] When the flue gas enters the filter box 8 through the first pipe 4, it will first enter the first cavity 13, and the flue gas can be preliminarily filtered through the first mesh plate 14 to filter out larger particulate impurities in the flue gas. The flue gas after the preliminary filtration will enter the filter cavity 18, and will be filtered twice through the adsorption core 11. The flue gas after the second filtration will be filtered for the third time through the second mesh plate 16, and the flue gas after the third filtration will be transported to the SCR reactor 6 through the second pipe 5 for treatment.

[0062] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0063] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0064] It should be noted that, although several modules or units of the equipment for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to an embodiment of the present invention, the features and functions of two or more modules or units described above can be embodied in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into being embodied by multiple modules or units.

[0065] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the implementation of the present invention.

[0066] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

[0067] In the several embodiments provided in the present application, it should be understood that the disclosed systems, modules and methods can be implemented in other ways. For example, the module embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, modules or units, which can be electrical, mechanical or other forms.

[0068] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

Claims

1. A boiler flue gas SCR denitrification treatment system, characterized in that: include: A boiler body (1), a boiler economizer (2), a first pipeline (4), a dust removal device (3), a second pipeline (5), an SCR reactor (6) and a chimney (7) are connected in sequence; the SCR reactor denitrates the flue gas through a catalyst; the reaction principle of the catalyst includes a basic reaction part and a side reaction part, the basic reaction part includes: 4NO+4NH3+O2→4N2+6H2O; 2NO2+4NH3+O2→3N2+6H2O; the side reaction part includes: SO2+1 / 2O2→SO3; NH3+SO3+H2O→NH4HSO4; 2NH3+SO3+H2O→(NH4)2SO4; wherein: The catalyst in the SCR reactor meets the following requirements: activity ≥ 35 m / h, SO2 / SO3 conversion rate ≤ 1%, and resistance of a single-layer catalyst < 200 Pa; the catalyst in the SCR reactor is a wide-temperature arsenic-resistant catalyst; The catalyst in the SCR reactor is configured in the form of two operating layers and one standby layer; a first flow guide frame (60) is arranged between the inlet end of the SCR reactor and the first operating layer, and the first flow guide frame (60) is made of a material that is resistant to high temperatures and has high thermal conductivity; The first flow guide frame (60) is a truncated cone-shaped grid frame. The bottom surface of the first flow guide frame (60) is a plurality of heat-conducting rings (601) arranged overlapping each other. The inner side of the truncated cone side wall of the first flow guide frame is provided with a plurality of heat-conducting blades (602) evenly distributed around the center of the truncated cone. The angle between any two heat-conducting blades (602) is the same, and the angle between the side edge of any heat-conducting blade facing the center of the truncated cone and the center of the truncated cone is an acute angle.

2. The processing system according to claim 1, characterized in that The catalyst is a plate catalyst or a honeycomb catalyst added with arsenic-resistant elements.

3. The processing system according to claim 2, characterized in that The honeycomb catalyst is a 20-hole honeycomb catalyst.

4. The processing system according to claim 1, characterized in that The metal that is resistant to high temperatures and has high thermal conductivity is an aluminum alloy containing silicon or cubic boron nitride.

5. The processing system according to any one of claims 1 to 4, characterized in that: The dust removal device (3) comprises: a filter box (8), a sealing cover (9), a handle (10), an adsorption core (11), a bolt (12), a first mesh plate (14), a second mesh plate (16) and a connecting portion (17).

6. The processing system according to claim 5, characterized in that The top of the filter box (8) is provided with a connecting portion (17), the connecting portion (17) is communicated with the inside of the filter box (8), the top of the connecting portion (17) is buckled with a sealing cover (9), the sealing cover (9) is fixedly connected to the top of the connecting portion (17) by means of bolts (12), a handle (10) is fixedly connected at the center of the upper end surface of the sealing cover (9), and an adsorption core (11) is fixedly connected at the center of the lower end surface of the sealing cover (9), a first mesh plate (14) and a second mesh plate (16) are movably plugged into the inside of the filter box (8), the first mesh plate (14) and the second mesh plate (16) are arranged relatively parallel, the upper parts of the first mesh plate (14) and the second mesh plate (16) are both snap-fitted with the top of the filter box (8), and the two ends of the lower end surface of the sealing cover (9) are in contact with the top of the first mesh plate (14) and the top of the second mesh plate (16) respectively.

7. The processing system according to claim 6, characterized in that The adsorption core (11) is located between the first mesh plate (14) and the second mesh plate (16); a first cavity (13) communicating with the first pipe (4) is provided inside the filter box (8) at one end close to the first mesh plate (14); a second cavity (15) communicating with the second pipe (5) is provided inside the filter box (8) at one end close to the second mesh plate (16); and a filter cavity (18) is provided in the center of the filter box (8).

8. The processing system according to any one of claims 1 to 7, characterized in that: The boiler body (1) is used to output flue gas, which is transported to a dust removal device (3) through a boiler economizer (2) and a first pipeline (4); the dust removal device (3) is used to remove dust from the flue gas, and the flue gas after dust removal is transported to an SCR reactor (6) through a second pipeline (5); the SCR reactor (6) is used to denitrate the flue gas through a catalyst, and the flue gas after denitrification is transported to a chimney (7) through a fan for discharge.

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