Honeycomb type denitration ammonia spraying device

Abstract

The utility model discloses a honeycomb type denitration ammonia spraying device which is arranged on a flue and comprises an ammonia spraying pump, an ammonia spraying pipeline and an ammonia spraying layer, and the denitration ammonia spraying device is arranged between an outlet of a boiler hearth and an inlet of an SCR reactor; the ammonia spraying pump is connected with the ammonia spraying layer through an ammonia spraying pipeline; the ammonia spraying layer is arranged in the flue and is provided with an ammonia spraying ring pipe; the ammonia spraying layers are configured to be a first ammonia spraying layer, a second ammonia spraying layer and a third ammonia spraying layer from bottom to top, each ammonia spraying layer further comprises a plurality of ammonia spraying sub-branches, and the ammonia spraying sub-branches are configured to be of a honeycomb structure and are mutually independent. Compared with the prior art, the thought of multi-layer space and mutual staggered supplement is fully utilized, the ammonia spraying device is subjected to multi-layer ammonia spraying ring pipe arrangement, when each layer of ammonia spraying device completes the ammonia spraying task of an independent space layer, the configuration of ammonia spraying heads is also fully coordinated, the ammonia spraying heads are subjected to multi-point array in a horizontal plane area, and the ammonia spraying efficiency is improved. And the effect of considering both the plane and the three-dimensional space is achieved. According to the arrangement, the flue gas and the reducing medium can be effectively mixed, so that the flue gas and the reducing medium are subjected to multi-stage mixing in the flue gas flow, and the mixing effect is enhanced.

Description

Technical Field

[0001] This application relates to flue gas emissions from power plants, and particularly to the denitrification ammonia injection technology for flue gas emissions from power plants. Background Art

[0002] Flue gas emissions from coal-fired power plants are an important factor affecting environmental quality. Nitrogen oxides (NOx) generated during the operation of coal-fired power plants are one of the main pollution sources polluting the atmospheric environment. To protect the environment, the NOx emissions from coal-fired power plants must be strictly restricted. Currently, the main denitrification technology used in domestic power plants is the selective catalytic reduction (SCR) denitrification technology. This technology involves a reduction reaction between ammonia (NH3) and NOx in the flue gas to produce nitrogen (N2) and water. To meet the requirements of ultra-low emissions, by increasing the ammonia injection amount, the emissions of NOx can be reduced. However, excessive ammonia injection leads to a series of problems such as easy blockage of the air preheater, increased resistance of the system pipeline, increased power consumption of the system equipment, increased ammonia escape rate, and waste of ammonia raw materials. A main factor causing excessive ammonia injection is the uneven flow field of the flue gas and ammonia, and insufficient contact reaction between the media, which affects the effect of the reduction reaction.

[0003] Currently, the more commonly used ammonia injection method is the ammonia injection grid. The ammonia injection grid divides the flue gas duct cross-section into several longitudinal and transverse control regions, and ammonia is injected into each region by ammonia injection pipelines.

[0004] In the prior art, due to the relatively large cross-section of the SCR inlet flue gas duct, usually ranging from 4 to 8 meters, the flue gas flow field is complex, the flue gas deviation is large, and the flue gas flow velocity is uneven. The ammonia injection method using the ammonia injection grid can partially achieve the goal of zoning regulation. Due to the complexity of the aforementioned flue gas flow field, especially the large change in the flue gas flow field during the load increase and decrease of the unit, the fixed grid zoning method is not conducive to the full contact reaction between the reducing medium and the flue gas. Moreover, in the fixed zoning method, when a certain region fails or its use effect decreases, it causes obvious regional defects in the flue gas ammonia injection, affects the performance of the SCR reactor catalyst, results in an extremely unbalanced flue gas flow field, and is prone to exceed the emission standard. At the same time, due to the exceeded emission standard, it also leads to an increase in the control of the ammonia injection amount, causing the problem of excessive ammonia injection.

[0005] Based on the problem of uneven ammonia injection flow field and the inability to ensure the reliability of ammonia injection due to fixed ammonia injection blocks, the present invention proposes a honeycomb denitrification ammonia injection device. By arranging the hierarchical ammonia injection pipelines in a staggered manner and arranging the honeycomb nozzles, the uniformity of the flow field and the reliability of ammonia injection are increased. Summary of the Invention

[0006] The purpose of this application is to provide a honeycomb denitrification ammonia injection device, which increases the fluidity between the flue gas and the reducing agent, makes the ammonia injection more uniform, the reaction between the flue gas and ammonia more sufficient, and effectively improves the denitrification efficiency.

[0007] The present application discloses a denitration ammonia injection device, which is configured on a flue duct and includes: an ammonia injection pump, an ammonia injection pipeline, and an ammonia injection layer, wherein:

[0008] The denitration ammonia injection device is configured between the outlet of the boiler furnace and the inlet of the SCR reactor;

[0009] The ammonia injection pump is connected to the ammonia injection layer through the ammonia injection pipeline. The ammonia injection layer is configured in the flue duct and is provided with an ammonia injection header pipe;

[0010] The ammonia injection layer is configured from bottom to top as a first ammonia injection layer, a second ammonia injection layer, and a third ammonia injection layer. The multiple ammonia injection layers are arranged staggered. The first ammonia injection layer, the second ammonia injection layer, and the third ammonia injection layer are configured to form a side semi-multi-cellular spray or a side full-multi-cellular spray during ammonia injection through staggered distribution and mutual redundancy;

[0011] Each ammonia injection layer further includes a plurality of ammonia injection sub-branches, which are configured in a honeycomb structure and are independent of each other.

[0012] In a preferred example, each ammonia injection layer is provided with a manual isolation valve, a pneumatic isolation valve, and a pneumatic regulating valve.

[0013] In a preferred example, the pneumatic regulating valve is configured to ensure that the pressure of the ammonia injection layer is equal to the set value.

[0014] In a preferred example, the number of the ammonia injection sub-branches is 4-8.

[0015] In a preferred example, the ammonia injection pump is a variable frequency pump, and the ammonia injection pump is configured such that the ammonia injection amount is slightly greater than the ammonia injection demand.

[0016] In a preferred example, NOx gas analyzers are arranged at both the inlet and the outlet of the ammonia injection device in the flue duct.

[0017] In a preferred example, the ammonia injection pipeline includes an ammonia injection main pipeline and an ammonia injection branch pipeline.

[0018] In a preferred example, a flow meter is arranged on the ammonia injection main pipeline.

[0019] In a preferred example, the denitration ammonia injection device is configured on the vertical pipeline of the flue duct.

[0020] In a preferred example, a pressure transmitter is arranged on each ammonia injection branch.

[0021] The advantages of the present application are:

[0022] (1) The utility model proposes a honeycomb intelligent denitrification ammonia spraying device, which aims to solve the problems of increased corrosion of downstream equipment in the system, increased flue gas resistance, and increased frequency of catalyst failure caused by excessive ammonia spraying due to complex flue gas flow field and uneven ammonia spraying. The present invention makes full use of the idea of ​​multi-layer space and mutual interlacing and complementation, and arranges the ammonia spraying device with multi-layer ammonia spraying ring tubes. When each layer of ammonia spraying is arranged to complete the ammonia spraying task of an independent space layer, it also fully coordinates the configuration of the ammonia nozzle, so that it can be arranged in a multi-point array in the horizontal plane area, achieving the effect of taking both plane and three-dimensional space into consideration. This arrangement can effectively mix the flue gas and the reducing medium, so that it can be mixed in multiple stages in the flue gas process, thereby deepening its mixing effect.

[0023] (2) In order to refine the regulation and create conditions to avoid excessive ammonia injection, the utility model modularizes and makes the setting of the ammonia injection loop and the setting of the ammonia injection sub-branch as independent as possible. Each ammonia injection loop has an independent state detection element and an independent adjustment mechanism. At the same time, the ammonia injection sub-branches belonging to the ammonia injection loop also constitute independent branches, which can independently play the functions of input, exit and regulation of the branch. Since the mutual redundancy characteristics of the nozzle device are fully considered in the nozzle setting, the influence of the adjustment of a sub-branch on the entire ammonia injection system is fine from a three-dimensional perspective, which also promotes the realization of uniformity of the ammonia injection flow field.

[0024] (3) At the same time, the utility model fully considers the impact of equipment or pipeline failure on the system. In order to minimize the impact of local failures, the independence of the ammonia injection loop and the ammonia injection sub-branch is fully guaranteed. When a failure occurs in the ammonia injection sub-branch, the affected sub-branch will be withdrawn. When a failure occurs in the ammonia injection loop, the affected ammonia injection loop will be withdrawn. This setting ensures the reliability of the entire ammonia injection system.

[0025] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

[0026] The specification of this application records a large number of technical features, which are distributed in various technical solutions. If all possible combinations of technical features (i.e., technical solutions) of this application are listed, the specification will become overly lengthy. To avoid this problem, each of the technical features disclosed in the above-mentioned invention content of this application, each of the technical features disclosed in the following embodiments and examples, and each of the technical features disclosed in the drawings can be freely combined with each other to form various new technical solutions (all of these technical solutions shall be regarded as having been recorded in this specification), unless such a combination of technical features is technically infeasible. For example, in one example, features A + B + C are disclosed, and in another example, features A + B + D + E are disclosed. Features C and D are equivalent technical means that play the same role, and only one of them can be used technically and it is impossible to use both at the same time. Feature E can be combined with feature C technically. Then, the solution of A + B + C + D should not be regarded as having been recorded because it is technically infeasible, while the solution of A + B + C + E should be regarded as having been recorded. Description of the Drawings

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. It should be understood that the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other embodiments based on these drawings without creative efforts.

[0028] Figure 1 It is a system diagram of a denitration ammonia injection device according to an embodiment of this application;

[0029] Figure 2-1 It is a schematic diagram showing the setting of the ammonia injection layer of the first-side semi-multi-honeycomb array according to an embodiment of this application;

[0030] Figure 2-2 It is a schematic diagram showing the setting of the ammonia injection layer of the second-side semi-multi-honeycomb array according to an embodiment of this application;

[0031] Figure 2-3 It is a schematic diagram showing the setting of the ammonia injection layer of the third-side semi-multi-honeycomb array according to an embodiment of this application;

[0032] Figure 3-1 It is a schematic diagram showing the setting of the ammonia injection layer of the first-side full-multi-honeycomb array according to an embodiment of this application;

[0033] Figure 3-2 It is a schematic diagram showing the setting of the ammonia injection layer of the second-side full-multi-honeycomb array according to an embodiment of this application;

[0034] Figure 3-3 It is a schematic diagram showing the setting of the ammonia injection layer of the third-side full-multi-honeycomb array according to an embodiment of this application.

[0035] Description of reference numerals:

[0036] 1- boiler furnace; 2- ammonia injection pipeline; 3- ammonia injection pump; 4- third ammonia injection layer; 5- second ammonia injection layer; 6- first ammonia injection layer; 7- NO X Gas analyzer; 8-SCR reactor; 9-flow meter. DETAILED DESCRIPTION

[0037] Through extensive and in-depth research, the inventors have proposed a honeycomb denitrification ammonia spraying device, which aims to solve the problems of increased corrosion of downstream equipment in the system, increased flue gas resistance, and increased frequency of catalyst failure caused by excessive ammonia spraying due to complex flue gas flow field and uneven ammonia spraying. The present invention makes full use of the idea of ​​multi-layer space and mutual interlaced complementation, and sets up ammonia spraying device with multi-layer ammonia spraying ring tubes. When each layer of ammonia spraying is set to complete the ammonia spraying task of the independent space layer, it also fully coordinates the configuration of the ammonia nozzle, so that it can be arranged in a multi-point array in the horizontal plane area, achieving the effect of taking both plane and three-dimensional space into consideration. This setting can effectively mix the flue gas and the reducing medium, so that it can be mixed in multiple stages in the flue gas process, and deepen its mixing effect.

[0038] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0039] The structure of a honeycomb type denitration and ammonia injection device described in this application is as follows Figure 1 As shown, it includes: an ammonia injection pump 3, an ammonia injection pipeline 2 and an ammonia injection layer, wherein:

[0040] The denitration and ammonia injection device is arranged between the boiler furnace 1 outlet and the SCR reactor 8 inlet;

[0041] The ammonia injection pump is connected to the ammonia injection layer through the ammonia injection pipeline 2, and the ammonia injection layer is arranged in the flue and is equipped with an ammonia injection ring pipe;

[0042] The ammonia spraying layer is configured from bottom to top as the first ammonia spraying layer 6, the second ammonia spraying layer 5 and the third ammonia spraying layer 4, and the multiple ammonia spraying layers are staggered. The first ammonia spraying layer 6, the second ammonia spraying layer 5 and the third ammonia spraying layer 4 are staggered and distributed, and the mutually redundant form is configured to form a side half multi-honeycomb spray or a side full multi-honeycomb spray when spraying ammonia; each ammonia spraying layer is configured with a manual isolation valve, a pneumatic isolation valve and a pneumatic regulating valve. The ammonia spraying pipeline includes an ammonia spraying main pipeline and an ammonia spraying branch pipeline, and the pneumatic regulating valve is configured to ensure that the pressure of the ammonia spraying layer is equal to the set value.

[0043] Each of the ammonia injection layers further includes a plurality of ammonia injection sub-branches, the ammonia injection sub-branches are configured in a honeycomb structure, and the ammonia injection sub-branches are independent of each other. Optionally, in one embodiment, the number of the ammonia injection sub-branches is 4-8, and the ammonia injection pump is a variable frequency pump, and the ammonia injection pump is configured to have an ammonia injection amount greater than the ammonia injection demand.

[0044] Optionally, in one embodiment, NOx gas analyzers 7 are arranged at both the inlet and the outlet of the ammonia injection device in the flue, and a flow meter 9 is arranged on the ammonia injection main pipeline.

[0045] Optionally, in one embodiment, the denitration ammonia injection device is arranged on the vertical pipeline of the flue, and a pressure transmitter is arranged on each ammonia injection branch.

[0046] Embodiment 1

[0047] The side semi-multi-honeycomb array arrangement of an embodiment of the present utility model is as Figures 2-1 to 2-3 shown.

[0048] In this embodiment, a manual isolation valve AA801, a pneumatic isolation valve AA811 and a pneumatic regulating valve AA812 of the ammonia injection pipe of this layer are arranged in each ammonia injection layer. Four pressure transmitters P81-P84 are arranged at the positions of the near-layer sub-branches around the ammonia injection loop pipe of this layer for detecting the ammonia transportation pressure state of the ammonia injection loop pipe. The pneumatic regulating valve AA812 of each layer is used to adjust the values of P81-P84 to be equal to the set value. The pneumatic isolation valve AA811 is used to control the overall isolation of this ammonia injection layer during equipment failure or other transient failures. The manual isolation valve AA801 is a backup isolation means. When the pressure of the four pressure transmitters P81-P84 of the sub-branches of this layer is abnormally low, the possibility of a leaking pipe should be considered, and the ammonia injection device of this layer should be isolated according to the inspection results.

[0049] The ammonia injection sub-branches are arranged in each ammonia injection layer according to the honeycomb structure. In this embodiment, taking the setting of 5 sub-branches as an example, in actual use, it can be adjusted according to the pipe interface size, flue gas flow field characteristics, etc. Taking Figure 2-1For example, set up sub-branches 1 to 5. In sub-branch 1, set up the pneumatic regulating valve AA101, manual isolation valve AA001, pressure transmitter P01, and spray head device S11 - S13 for the sub-branch. In sub-branch 2, set up the pneumatic regulating valve AA102, manual isolation valve AA002, pressure transmitter P02, and spray head device S21 - S22. And so on. In sub-branch 5, set up the pneumatic regulating valve AA105, manual isolation valve AA005, pressure transmitter P05, and spray head device S51 - S53. The pneumatic regulating valves of each sub-branch are used to adjust the pressure of the sub-branch to be equal to the set value. The input of the pressure control loop, the feedback value of the system pressure state, is collected by the pressure transmitters set on the sub-branches. The manual isolation valves of the sub-branches are used for the maintenance of the sub-branches or isolation for other reasons. When the valve position of the pneumatic regulating valve of a certain sub-branch is large and the pressure of the sub-branch is abnormally low, the possibility of a leaking pipe should be considered, and the ammonia spraying device of the sub-branch should be isolated after inspection and based on the inspection results.

[0050] For the sake of the full uniformity of the flow field and the full mixing of flue gas and ammonia, the ammonia spraying layers of each layer are arranged in a staggered structure, such as Figure 2-1 In the arrangement of the ammonia spraying layer of the first-side semi-multi-cell array, the ammonia spray head devices are arranged in a vertical column in a staggered manner, and the sub-branches are arranged in a staggered manner on both sides of the flue duct, so as to ensure the overall uniformity and reliability of the flue gas field. In order to Figure 2-1 constitute an effective complementary and superposition effect on the ammonia spraying layer of the first-side semi-multi-cell array, Figure 2-2 In the arrangement of the ammonia spraying layer of the second-side semi-multi-cell array, an oblique arrangement structure is adopted, and the spray heads are arranged according to the honeycomb center. Similarly, the sub-branches are arranged in a staggered manner on both sides of the flue duct. Figure 2-3 In the arrangement of the ammonia spraying layer of the third-side semi-multi-cell array, a horizontal structure is adopted, the spray heads are arranged at the honeycomb points and the edges of the honeycombs, and the sub-branches are arranged in a staggered manner on both sides of the flue duct. Figure 2-1 、 Figure 2-2 and Figure 2-3 The arrangement of the three-layer ammonia spraying system shown constitutes an effective spatial multi-layer staggered complementary structure, which can effectively promote the full reaction of the reducing medium and the flue gas, and is beneficial to strengthening the stability and uniformity of the flue gas flow field from the spatial angle.

[0051] It should be noted that for Method 1 proposed in the present invention, that is, the semi-multi-cell array type, the arrangement of the ammonia spraying layer can be reorganized and coordinated according to the honeycomb architecture proposed in the present invention. The mutual relationship between the three layers is not fixed either. It can be mutually layer-matched and reconstructed according to the flue gas field conditions, the characteristics of the flue gas components, and the feedback of the test operation, so as to achieve the functions of plane-related coordination and spatial mutual promotion.

[0052] Embodiment 2

[0053] The arrangement of the full multi-cell array on one side of the present utility model is as shown in Figures 3-1 to 3-3 shown

[0054] In this embodiment, 5 sub-branches are provided for the first and second ammonia injection layers, and a sub-branch pneumatic regulating valve, a manual isolation valve, a pressure transmitter and a spray head device are provided for each sub-branch. The setting conditions and equipment functions are the same as those in Embodiment 1, that is, the side semi-multi-cell array structure. At the same time, in order to increase the deep penetration of the multi-layer ammonia injection reaction, the present invention provides 6 sub-branches for the third ammonia injection layer of the side full multi-cell array, and 3 spray heads are arranged for each sub-branch to complete the function of spatial multi-layer deepening.

[0055] It should be noted that in the application documents of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one" does not exclude the existence of another identical element in the process, method, article or device comprising the element. In the application documents of this patent, if it is mentioned that an act is performed according to a certain element, it means that the act is performed at least according to the element, including two cases: the act is performed only according to the element, and the act is performed according to the element and other elements. Expressions such as multiple, multiple times, multiple types include 2, 2 times, 2 types, and more than 2, more than 2 times, more than 2 types.

[0056] In this application, all directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indicators will also change accordingly.

Claims

1. A honeycomb denitration ammonia injection device, characterized in that, The denitration ammonia injection device is arranged on the flue duct and includes: an ammonia injection pump, an ammonia injection pipeline, and an ammonia injection layer, where: The denitration ammonia injection device is arranged between the outlet of the boiler furnace and the inlet of the SCR reactor; The ammonia injection pump is connected to the ammonia injection layer through the ammonia injection pipeline, and the ammonia injection layer is arranged in the flue duct and is provided with an ammonia injection ring pipe; The ammonia injection layer is arranged from bottom to top as a first ammonia injection layer, a second ammonia injection layer, and a third ammonia injection layer. The multiple ammonia injection layers are arranged staggered. The first ammonia injection layer, the second ammonia injection layer, and the third ammonia injection layer are configured in a form of staggered distribution and mutual redundancy to form a honeycomb type spray during ammonia injection; Each ammonia injection layer further includes a plurality of ammonia injection sub-branches, and the ammonia injection sub-branches are configured in a honeycomb structure and are independent of each other.

2. The honeycomb denitration ammonia injection device according to claim 1, wherein Each ammonia injection layer is provided with a manual isolation valve, a pneumatic isolation valve, and a pneumatic regulating valve.

3. The honeycomb denitration ammonia injection device according to claim 2, characterized in that, The pneumatic regulating valve is configured to ensure that the pressure of the ammonia injection layer is equal to the set value.

4. The honeycomb denitration ammonia injection device according to claim 1, characterized in that, The number of the ammonia injection sub-branches is 4 - 8.

5. The honeycomb denitration ammonia injection device according to claim 1, wherein, The ammonia injection pump is a variable frequency pump, and the ammonia injection pump is configured to have an ammonia injection amount slightly larger than the ammonia injection demand.

6. The honeycomb denitration ammonia injection device according to claim 1, wherein, NO gas analyzers are configured at both the inlet and outlet of the ammonia injection device in the flue duct. x Gas analyzer.

7. The honeycomb denitration ammonia injection device according to claim 1, characterized in that, The ammonia injection pipeline includes an ammonia injection main pipe pipeline and an ammonia injection branch pipe pipeline.

8. The honeycomb denitration ammonia injection device according to claim 7, characterized in that, A flow meter is arranged on the ammonia injection main pipe pipeline.

9. The honeycomb denitration ammonia injection device according to claim 1, characterized in that, The denitration ammonia injection device is arranged on the vertical pipeline of the flue duct.

10. The honeycomb denitration ammonia injection device according to claim 1, characterized in that, A pressure transmitter is arranged on each ammonia injection sub-branch.

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