High-temperature flue gas extracting and mixing device for realizing wide-load denitration of boiler

Abstract

The utility model relates to the technical field of flexible peak regulation of power plant boilers, and particularly discloses a high-temperature flue gas extracting and mixing device for realizing wide-load denitration of a boiler, which comprises a flue gas taking hole arranged at a low-temperature superheater steering chamber of the boiler, one end of the multi-section bypass pipeline is connected with a smoke taking hole pipeline, and the other end of the multi-section bypass pipeline is connected with a main flue pipeline; the stepped flue gas mixing device is arranged in the joint of the main flue and the multi-section bypass pipeline; wherein the end, connected with the smoke taking hole, of the multi-section bypass pipeline is obliquely upwards arranged by 20-30 degrees in the smoke output direction; and a divergent outlet is formed at the connecting end of the multi-section bypass pipeline and the main flue. According to the utility model, by adjusting the flowing scheme of the boiler smoke in the boiler, the heat exchange amount of each stage of heat exchange equipment is reasonably distributed, the influence of non-uniform smoke temperature heat exchange caused by the load change of the boiler is effectively controlled, the temperature of the smoke entering denitration equipment is effectively increased, and the safe and efficient operation of the boiler is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of power plant boiler flexibility peak regulation, and specifically relates to a high-temperature flue gas extraction and mixing device for realizing boiler wide-load denitration. BACKGROUND

[0002] Under the "30·60" double carbon target, the proportion of photovoltaic and wind power will inevitably increase. Due to the instability and time period of photovoltaic and wind power, the position of coal-fired power as ballast still needs to be retained. However, in order to consume new energy and maintain the stability of the power grid, coal-fired power units are faced with long-term low-load operation. This operation mode deviates from the design condition, resulting in low boiler efficiency, unstable combustion, serious flue dust, high oxygen content at the furnace outlet, low flue gas temperature, and other problems, which further lead to difficulties in denitration investment and the generation of a large amount of NOx due to high oxygen content in the furnace. In addition, the blending of low-quality coal makes the above problems more prominent.

[0003] Therefore, in order to solve and alleviate the above problems, the technical personnel in the field urgently need to develop a technical scheme that can make the boiler safe and economic under low load. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the utility model wants to solve the technical problem in the prior art, so as to provide a high-temperature flue gas extraction and mixing device for realizing boiler wide-load denitration.

[0005] A high-temperature flue gas extraction and mixing device for realizing boiler wide-load denitration, comprising:

[0006] A smoke extraction hole opened at the low-temperature superheater turning chamber of the boiler;

[0007] A multi-section bypass pipeline connected at one end to the smoke extraction hole pipeline and at the other end to the main flue pipeline;

[0008] And a stepped flue gas mixing device arranged in the connection between the main flue and the multi-section bypass pipeline;

[0009] Among them, the connection end of the multi-section bypass pipeline to the smoke extraction hole is arranged at an angle of 20-30º upward in the flue gas output direction;

[0010] The connection end of the multi-section bypass pipeline to the main flue adopts a gradually expanding outlet.

[0011] Preferably, the smoke extraction hole comprises a first smoke extraction hole and a second smoke extraction hole;

[0012] The first smoke extraction hole and the second smoke extraction hole are symmetrically arranged in a double-hole manner.

[0013] Preferably, the multi-section bypass pipeline is fixed by a guide support device for limiting displacement change of the bypass flue caused by stress change during operation.

[0014] Preferably, the multi-section bypass pipeline is composed of a first pipeline, a second pipeline, a third pipeline and a fourth pipeline connected in sequence.

[0015] The first pipeline is connected with the smoke taking hole; and the first pipeline is arranged obliquely upward by 20-30º according to the smoke output direction.

[0016] The second pipeline is of a bending structure, so as to connect the first pipeline with the vertical third pipeline.

[0017] The fourth pipeline adopts a gradually expanding structure, and a gradually expanding outlet is connected with the main flue pipeline.

[0018] Preferably, a manhole door and an adjusting baffle door are arranged on the third pipeline.

[0019] Preferably, the ladder-shaped smoke mixing device comprises a pair of main flue guide baffles and bypass smoke baffles; one main flue guide baffle and one bypass smoke baffle are connected.

[0020] Each bypass smoke baffle is of the same size, and the total length of all bypass smoke baffles and the size of the gradually expanding outlet are matched.

[0021] The heights of the plurality of main flue guide baffles are sequentially lowered, and the main flue guide baffles are sequentially arranged in ascending order according to the smoke output direction of the main flue, so as to form a ladder-shaped structure; the total height of all main flue guide baffles and the size of the main flue are matched.

[0022] Preferably, the smoke taking hole adopts a multi-hole structure.

[0023] The length of a single hole is ≤4000mm.

[0024] The width of a single hole is ≤1000mm.

[0025] The technical scheme of the utility model has the following advantages:

[0026] 1. The utility model adjusts the flow scheme of the boiler flue by increasing the flue bypass composed of the smoke taking hole and the multi-section bypass pipeline, reasonably distributes the heat exchange capacity of the heat exchange equipment at each level, effectively controls the influence of uneven heat exchange caused by the change of the boiler load, effectively improves the flue gas temperature entering the desulfurization equipment, and ensures the safety and efficient operation of the boiler.

[0027] 2. The utility model increases the smoke mixing effect by arranging the ladder-shaped smoke mixing device, so that the temperature distribution at the desulfurization inlet is more uniform, and the problem of reduced desulfurization effect caused by uneven temperature is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings described in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0029] Figure 1 The overall structure front view of the high-temperature flue gas extraction and mixing device provided by the present application is shown in the figure.

[0030] Figure 2 The schematic diagram of the smoke extraction hole arranged symmetrically in a double-hole mode provided by the present application is shown in the figure.

[0031] Figure 3 The structure diagram of the ladder-type flue gas mixing device provided by the present application is shown in the figure.

[0032] Explanation of reference signs:

[0033] 1-boiler, 2-main flue, 3-smoke extraction hole, 4-multistage bypass pipeline, 41-first pipeline, 42-second pipeline, 43-third pipeline, 44-fourth pipeline, 5-ladder-type flue gas mixing device, 51-main flue flow guide baffle, 52-bypass flue baffle, 6-guiding support device, 7-manhole door, 8-adjustable baffle door, 9-non-metal expansion joint. DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be described in detail below with reference to the drawings. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0036] In the description of the utility model, it is to be explained that, unless there is definite stipulation and limitation, the term "mount", "link", "connect" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connect, can be mechanical connection, also can be electrical connection, can be direct connection, also can be indirectly connected through intermediate medium, can be the intercommunication of two elements. For ordinary skilled in the art, the specific meaning of the above-mentioned term in the utility model can be understood according to specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the utility model described below can be combined with each other as long as there is no conflict.

[0038] Embodiment 1

[0039] As Figure 1 The embodiment discloses a high-temperature flue gas extraction and mixing device for realizing boiler wide-load denitration, comprising:

[0040] A smoke extraction hole 3 is arranged at the low-temperature superheater turning chamber of the boiler 1.

[0041] A multi-section bypass pipeline 4 is connected to the smoke extraction hole 3 at one end and connected to the main flue 2 at the other end.

[0042] And a ladder-type flue gas mixing device 5 is arranged at the connection between the main flue 2 and the multi-section bypass pipeline 4.

[0043] Among them, the connection end of the multi-section bypass pipeline 4 and the smoke extraction hole 3 is arranged obliquely upward 20-30º according to the flue gas output direction.

[0044] The connection end of the multi-section bypass pipeline 4 and the main flue 2 adopts a gradually expanding outlet.

[0045] Specifically:

[0046] It should be noted that in this embodiment, in order to ensure that the flue gas temperature entering the SCR system is ≥300℃ from 25% load to full load, an opening is arranged at the horizontal low-temperature superheater turning chamber and a smoke window type smoke extraction hole 3 is additionally arranged, a part of high-temperature flue gas is led out to the horizontal flue before the SCR system inlet, and the high-temperature flue gas is mixed uniformly with the low-temperature flue gas after the economizer, so that the flue gas temperature entering the SCR system is ≥300℃.

[0047] As Figure 2 In this embodiment, the smoke extraction hole 3 includes a first smoke extraction hole and a second smoke extraction hole.

[0048] The first smoke extraction hole and the second smoke extraction hole are symmetrically arranged in a double-hole manner to increase the smoke inlet area.

[0049] Further, the smoke extraction hole 3 in the embodiment is of a multi-hole structure.

[0050] The length of the single hole is ≤4000mm.

[0051] The width of the single hole is ≤1000mm.

[0052] It is to be noted that in actual application, the specific layout is as follows: the wall tube is drawn apart at the horizontal low-temperature superheater inlet part;

[0053] The smoke window type smoke extraction hole 3 for leading out flue gas is arranged on the rear wall superheater above the horizontal low-temperature superheater, and the first smoke extraction hole and the second smoke extraction hole are symmetrically arranged on the left and right sides to form two bypass flues which are connected with the multi-section bypass pipeline 4.

[0054] The position of the rear wall superheater above the low-temperature superheater is the same as the position of the low-temperature superheater turning chamber.

[0055] The wall tube is drawn apart in the range of the rear wall smoke window, and the wall tube is drawn apart by one tube every one tube to the outside of the furnace, for example Figure 2 .

[0056] For example Figure 1 In the embodiment, the multi-section bypass pipeline 4 is fixed by the guide support device 6 for limiting the displacement change of the bypass flue caused by the stress change in the running process. In the embodiment, two non-metal expansion joints 9 are arranged on the multi-section bypass pipeline 4 to prevent the thermal expansion of the boiler 1 and the bypass flue.

[0057] In the embodiment, the multi-section bypass pipeline 4 is composed of the first pipeline 41, the second pipeline 42, the third pipeline 43 and the fourth pipeline 44 which are sequentially connected in pipeline;

[0058] The first pipeline 41 is connected with the smoke extraction hole 3; the first pipeline 41 is arranged obliquely upward by 20-30º according to the flue gas output direction; and one non-metal expansion joint 9 is arranged on the first pipeline 41.

[0059] The second pipeline 42 is of a bending structure to connect the first pipeline 41 with the vertical third pipeline 43; and one non-metal expansion joint 9 is arranged on the third pipeline 43.

[0060] The fourth pipeline 44 is of a gradually expanding structure, and the gradually expanding outlet is connected with the main flue 2 in pipeline to increase the flue gas amount after the flue gas is extracted.

[0061] In the third pipeline 43 of the embodiment, manhole doors 7 and regulating baffle doors 8 are arranged. In practical application, the number of manhole doors 7 and regulating baffle doors 8 is set according to actual demand; the regulating baffle doors 8 at least include one shut-off baffle door and one regulating baffle door, the regulating baffle doors 8 are controlled by electric actuators, and the regulating baffle doors 8 and the actuators are selected according to the bidding technical specification. A platform escalator is arranged at each regulating baffle door, and a manhole door 7 is arranged near the baffle door to facilitate maintenance, inspection and removal of accumulated dust. The manhole doors 7 are individually insulated to facilitate opening.

[0062] In the embodiment, the stepped flue gas mixing device 5 includes pairs of main flue guide baffles 51 and bypass flue baffles 52; one main flue guide baffle 51 and one bypass flue baffle 52 are connected; the arrangement is used to increase the mixing effect of flue gas, so that the temperature distribution at the desorption inlet is more uniform, and the problem of desorption effect decline caused by temperature unevenness is reduced.

[0063] Each bypass flue baffle 52 has the same size, and the total length of all bypass flue baffles 52 and the size of the gradually expanding outlet are matched.

[0064] The heights of the plurality of main flue guide baffles 51 are sequentially reduced and arranged in a stepped structure according to the flue gas output direction of the main flue 2; the total height of all main flue guide baffles 51 and the size of the main flue 2 are matched.

[0065] Obviously, the above embodiment is only an example for clear illustration, and is not a limitation on the implementation. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the implementations do not need to be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A high-temperature flue gas extraction and mixing device for realizing boiler wide-load denitration, characterized in that, The utility model relates to a kind of boiler bypass smoke flue structure, including: The smoke hole (3) opened at the low-temperature superheater turning chamber of boiler (1); Multi-section bypass pipeline (4) with one end pipeline connection with smoke hole (3), the other end pipeline connection with main flue (2); And ladder type flue gas mixing device (5) is arranged in the connection place of main flue (2) and multi-section bypass pipeline (4); Wherein, the connecting end of multi-section bypass pipeline (4) and smoke hole (3) is arranged 20-30 ° obliquely upwards according to flue gas output direction; The connecting end of multi-section bypass pipeline (4) and main flue (2) uses gradually expanded type outlet.

2. The high temperature flue gas extraction and mixing device of claim 1, wherein, The smoke hole (3) includes first smoke hole and second smoke hole; First smoke hole and second smoke hole are symmetrically arranged in double-aperture mode.

3. The high temperature flue gas extraction and mixing device of claim 1, wherein, Multi-section bypass pipeline (4) is fixed by guide support device (6), for limiting displacement change of bypass flue caused by stress change in operation process.

4. The high temperature flue gas extraction and mixing device of claim 1, wherein, Multi-section bypass pipeline (4) is sequentially pipeline connected by first pipeline (41), second pipeline (42), third pipeline (43) and fourth pipeline (44); Wherein, the first pipeline (41) is connected with smoke hole (3);The first pipeline (41) is arranged 20-30 ° obliquely upwards according to flue gas output direction; Second pipeline (42) is a bending structure, so that first pipeline (41) is connected with vertical third pipeline (43); Fourth pipeline (44) uses gradually expanded type structure, and gradually expanded type outlet is connected with main flue (2) pipeline.

5. The high temperature flue gas extraction and mixing device of claim 4, wherein, Manhole door (7) and adjusting baffle door (8) are opened on third pipeline (43).

6. The high temperature flue gas extraction and mixing device of claim 5, wherein, Ladder type flue gas mixing device (5) includes a pair of main flue guide baffle (51) and bypass flue gas baffle (52);One main flue guide baffle (51) and one bypass flue gas baffle (52) are connected; Each bypass flue gas baffle (52) is same in size, and the total length of all bypass flue gas baffles (52) and gradually expanded type outlet size are adapted; The height of multiple main flue guide baffles (51) is sequentially reduced, and sequentially set according to flue gas output direction of main flue (2), to form ladder type structure;The height of all main flue guide baffles (51) and the size of main flue (2) are adapted.

7. The high temperature flue gas extraction and mixing device of claim 1, wherein, The smoke hole (3) uses multi-hole type structure; The length of single hole is ≤4000mm; The width of single hole is ≤1000mm.

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