CN115325554A - Flue and generating set - Google Patents

Abstract

The invention provides a flue and a generator set. The flue of the invention comprises: the first shell is provided with a flue cavity, a first inlet, a first outlet and an ash discharge port, wherein the first inlet, the first outlet and the ash discharge port are communicated with the flue cavity; the second shell is located in the flue cavity, the first shell is sleeved on the outer side of the second shell, the first shell and the second shell are arranged at intervals, the distance between the inner wall surface of the first shell and the outer wall surface of the second shell is smaller than or equal to a preset value, the inner wall surface of the first shell and the outer wall surface of the second shell limit an ash falling cavity, an ash falling through hole penetrating through the second shell is formed in the second shell, and the ash falling through hole is communicated with the flue gas cavity and the ash falling cavity. Therefore, the flue according to the invention has the advantage of facilitating the removal of solid particles from flue gases.

Description

Flue and generating set

Technical Field

The invention relates to the technical field of inlet flue structures of denitration reactors, in particular to a flue and a generator set.

Background

In the related art, the denitration inlet flue of the coal-fired power generation unit usually enters the denitration reactor from the outlet of the economizer after entering the top horizontal flue through the vertical uptake flue, and then enters the inlet flue of the air preheater. The design of the flue usually arranges a denitration ash hopper at the bottom of the vertical ascending flue, so that thicker particles which cannot ascend with flue gas and enter the reactor fall into the ash hopper and are conveyed out of a denitration system.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the embodiment of the invention provides a flue and a generator set.

The flue of the embodiment of the invention comprises:

the first shell is provided with a flue cavity, a first inlet, a first outlet and an ash discharge port, the first inlet, the first outlet and the ash discharge port are communicated with the flue cavity, the ash discharge port is formed in the bottom of the flue cavity, the first inlet is used for introducing flue gas into the flue cavity, the first outlet is used for discharging the flue gas in the flue cavity, the ash discharge port is used for discharging solid particles in the flue cavity, and an ash hopper communicated with the ash discharge port is arranged on the outer side of the first shell;

the second shell is located in the flue cavity, the first shell is sleeved on the outer side of the second shell, the first shell and the second shell are arranged at intervals, the distance between the inner wall surface of the first shell and the outer wall surface of the second shell is smaller than or equal to a preset value, an ash falling cavity is limited by the inner wall surface of the first shell and the outer wall surface of the second shell, an ash falling cavity is limited by the inner wall surface of the second shell, the ash falling cavity is communicated with the first inlet, the first outlet and the ash discharge port, the ash falling cavity is communicated with the ash discharge port, an ash falling through hole penetrating through the ash falling through hole is formed in the second shell, and the ash falling through hole is communicated with the ash falling cavity and the ash falling cavity.

Therefore, the flue according to the embodiment of the invention has the advantage of facilitating the removal of solid particles in the flue gas.

In some embodiments, first casing includes the body, the body with the second casing is along the annular casing of vertical extension, the body cover is established the second casing outside and with the second casing is injectd the ash falling cavity, first import is located the below of first export, the ash discharge port is established the bottom of body, the top in ash falling cavity is sealed, the export in ash falling cavity is seted up the bottom in ash falling cavity and orientation the ash discharge port.

In some embodiments, the ash falling through holes are multiple, the ash falling through holes are strip-shaped or block-shaped, and the ash falling through holes are spaced;

or, the ash falling through hole extends spirally along the extending direction of the second shell.

In some embodiments, the distance between the first shell and the second shell in the inner and outer directions is less than or equal to 10 cm.

In some embodiments, a swirling device is disposed in the flue gas chamber, and the swirling device is configured to rotate flue gas entering the flue gas chamber, and the swirling device includes at least one of a swirling vane and a deflector group.

In some embodiments, the flue gas chamber comprises a plurality of partitions, each partition is communicated with the first inlet, the first outlet and the ash discharge port, the partitions are arranged in a horizontal direction, and the cyclone device is matched with the plurality of partitions to rotate the flue gas entering the partitions.

In some embodiments, a plurality of the partitions are arranged in parallel along a first horizontal direction, and the rotation directions of the flue gas in two adjacent partitions are opposite.

In some embodiments, on a cross section perpendicular to the up-down direction, a projection of each of the partitions is one of a square, a circle, and a regular polygon.

In some embodiments, a plurality of partition plates are arranged in the second casing, the partition plates divide the flue gas cavity into a plurality of partitions, the thickness direction of each partition plate is a horizontal direction, each partition plate is provided with a partition plate cavity and a partition plate through hole, the partition plate cavities are communicated with the ash discharge port, the partition plate through holes penetrate through the partition plates, and the partition plate cavities are communicated with the flue gas cavities through the partition plate through holes.

The invention also provides a generator set, comprising:

a coal economizer;

a denitration reactor;

the outlet of the economizer is communicated with the first inlet of the flue, and the inlet of the denitration reactor is communicated with the first outlet of the flue.

Drawings

FIG. 1 is a front view of a flue according to an embodiment of the present invention.

FIG. 2 is a top view of a flue according to an embodiment of the invention.

FIG. 3 is a state diagram of the use of a flue according to an embodiment of the invention.

Reference numerals:

a flue 100;

the device comprises a first shell 1, a flue cavity 11, a first inlet 12, a first outlet 13, an ash discharge port 14, a body 15, an inlet pipe 16 and an outlet pipe 17;

the second shell 2, an ash falling cavity 21, a flue gas cavity 22, an ash falling through hole 23 and a subarea 24;

an ash hopper 3;

denitration reactor 4.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A flue 100 according to an embodiment of the present invention is described below with reference to the drawings. As shown in fig. 1 to 3, a stack 100 according to an embodiment of the present invention includes a first housing 1 and a second housing 2.

The first casing 1 has a flue chamber 11 and a first inlet 12, a first outlet 13 and an ash discharge 14 communicating with the flue chamber 11. The ash discharge port 14 is arranged at the bottom of the flue cavity 11, the first inlet 12 is used for introducing flue gas into the flue cavity 11, the first outlet 13 is used for discharging the flue gas in the flue cavity 11, the ash discharge port 14 is used for discharging solid particles in the flue cavity 11, and the ash hopper 3 communicated with the ash discharge port 14 is arranged on the outer side of the first shell 1.

The second casing 2 is located in the flue cavity 11, the first casing 1 is sleeved on the outer side of the second casing 2, the first casing 1 and the second casing 2 are arranged at intervals, and the distance between the inner wall surface of the first casing 1 and the outer wall surface of the second casing 2 is smaller than or equal to a preset value. An ash falling cavity 21 is limited by the inner wall surface of the first shell 1 and the outer wall surface of the second shell 2, a smoke cavity 22 is limited by the inner wall surface of the second shell 2, the smoke cavity 22 is communicated with the first inlet 12, the first outlet 13 and the ash discharge port 14, the ash falling cavity 21 is communicated with the ash discharge port 14, an ash falling through hole 23 penetrating through the second shell 2 is formed in the second shell 2, and the ash falling through hole 23 is communicated with the smoke cavity 22 and the ash falling cavity 21.

According to the flue 100 provided by the embodiment of the invention, the second shell 2 is arranged in the flue cavity 11, so that the inner wall surface of the first shell 1 and the outer wall surface of the second shell 2 define the ash falling cavity 21, the inner wall surface of the second shell 2 defines the flue gas cavity 22, and the ash falling through hole 23 is communicated with the flue gas cavity 22 and the ash falling cavity 21. Thereby, after the flue gas enters the flue gas chamber 22 (flue chamber 11) from the first inlet 12, it moves in the extending direction of the flue gas chamber 22, and then exits the flue gas chamber 22 (flue chamber 11) from the first outlet 13. In the above process, some (heavier) solid particles in the flue gas move in the flue gas chamber 22 towards the ash discharge 14 and exit the flue 100; some solid particles will impact the second housing 2 during the flow with the flue gas and will during the impact pass through the ash drop through hole 23 into the ash drop chamber 21.

The distance between the inner wall surface of the first shell 1 and the outer wall surface of the second shell 2 is less than or equal to a preset value, so that the flow speed of flue gas in the ash falling cavity 21 is far lower than the flow speed of flue gas in the flue gas cavity 22, solid particles entering the ash falling cavity 21 are difficult to penetrate the ash falling through hole 23 again and are brought to the first outlet 13 by the flue gas in the flue gas cavity 22, and then the solid particles in the ash falling cavity 21 are easy to move in the direction towards the ash discharge port 14 and are discharged out of the flue 100. Compared with the related art which only relies on the gravity of the solid particles to discharge the solid particles through the flue gas, the flue 100 provided with the ash falling cavity 21 can discharge more solid particles in the flue gas, and reduce the solid particles in the flue gas discharged from the first outlet 13 so as to prevent the solid particles in the flue gas from damaging the equipment for processing the flue gas in the next process.

Accordingly, the flue 100 according to embodiments of the present invention has the advantage of facilitating the removal of solid particles from flue gas.

As shown in fig. 1 to 3, a stack 100 according to an embodiment of the present invention includes a first housing 1 and a second housing 2.

The first casing 1 has a flue chamber 11 and a first inlet 12, a first outlet 13 and an ash discharge 14 communicating with the flue chamber 11. The ash discharge port 14 is arranged at the bottom of the flue cavity 11, the first inlet 12 is used for introducing flue gas into the flue cavity 11, the first outlet 13 is used for discharging the flue gas in the flue cavity 11, the ash discharge port 14 is used for discharging solid particles in the flue cavity 11, and the ash hopper 3 communicated with the ash discharge port 14 is arranged on the outer side of the first shell 1. Specifically, the ash bucket 3 is funnel-shaped, solid particles discharged from the ash discharge port 14 enter the ash bucket 3 and are easy to collect, and an outlet of the ash bucket 3 is communicated with an ash conveying system.

As shown in fig. 1, in some embodiments, the first housing 1 includes a body 15 and an inlet pipe 16 and an outlet pipe 17 in communication with the body 15, and the first inlet 12 is located below the first outlet 13. Specifically, the body 15 is an annular housing extending in the up-down direction, an outlet of the inlet pipe 16 is communicated with the lower part of the periphery of the body 15, an inlet of the inlet pipe 16 constitutes the first inlet 12, and the first inlet 12 is suitable for being connected with other devices (an economizer). The inlet of exit tube 17 communicates with the top of body 15, and the export of exit tube 17 constitutes first export 13, and first export 13 is suitable for linking to each other with other devices (denitration reactor 4). The ash discharge port 14 is provided at the bottom of the body 15, so that the ash discharge port 14 is easy to discharge solid particles. The up-down direction is shown by the arrow in fig. 1.

The second casing 2 is located in the flue cavity 11, the first casing 1 is sleeved on the outer side of the second casing 2, the first casing 1 and the second casing 2 are arranged at intervals, and the distance between the inner wall surface of the first casing 1 and the outer wall surface of the second casing 2 is smaller than or equal to a preset value. The inner wall surface of the first housing 1 and the outer wall surface of the second housing 2 define an ash falling chamber 21, and the inner wall surface of the second housing 2 defines a smoke chamber 22. Specifically, the second housing 2 is an annular housing extending in the up-down direction, the body 15 is sleeved outside the second housing 2 and defines an ash falling cavity 21 with the second housing 2, that is, the second housing 2 divides the flue cavity 11 into a flue gas cavity 22 and an ash falling cavity 21. The flue gas chamber 22 is in communication with the first inlet 12, the first outlet 13 and the ash discharge 14, whereby flue gas can enter and exit the flue gas chamber 22 and solid particles in the flue gas chamber 22 can move towards the ash discharge 14.

The second shell 2 is provided with an ash falling through hole 23 penetrating through the second shell, and the ash falling through hole 23 is communicated with the flue gas cavity 22 and the ash falling cavity 21. This facilitates the solid particles in the flue gas chamber 22 to enter the ash falling chamber 21 through the ash falling through holes 23 when the flue gas in the flue gas chamber 22 impacts the second housing 2. The ash falling cavity 21 is communicated with the ash discharge port 14, the top of the ash falling cavity 21 is closed, and the outlet of the ash falling cavity 21 is arranged at the bottom of the ash falling cavity 21 and faces the ash discharge port 14. Thereby make the top that falls grey chamber 21 not communicate with first export 13, the flue gas is difficult to discharge through the top that falls grey chamber 21 and falls grey chamber 21, thereby further can reduce the flow velocity of the flue gas that falls in grey chamber 21 and make the flue gas that falls in grey chamber 21 be difficult to the direction flow of first export 13, and then make in the grey chamber 21 that falls solid particle easily with drop downwards and through arrange in ash mouth 14 gets into ash bucket 3, from this solid particle in the reducible flue gas of following first export 13 exhaust, in order to prevent solid particle damage the equipment of next flow processing flue gas.

For example, the body 15 and the second casing 2 are both ring-shaped casings extending in the up-down direction and having a rectangular outer contour, the lower opening of the body 15 defines the ash discharge opening 14, the upper opening of the body 15 is connected to the inlet of the outlet pipe 17, and the top between the body 15 and the second casing 2 is closed. The body 15 and the lower portion of the front side of the second housing 2 are provided with through holes which communicate with the flue gas chamber 22 and the inlet of the inlet duct 16 so that the flue gas in the inlet duct 16 can enter the flue gas chamber 22 through the through holes. The front-back direction is shown by the arrows in the figure.

In some embodiments, the distance between the first casing 1 and the second casing 2 in the inward and outward direction is 10 cm or less. For example, the first case 1 and the second case 2 are spaced apart by 6 cm in the inward and outward direction.

In some embodiments, there are a plurality of ash falling through holes 23, the ash falling through holes 23 are in the shape of a strip or a block, and the plurality of ash falling through holes 23 are spaced. Thereby allowing solid particles in the flue gas chamber 22 to pass easily through the ash drop through-hole 23 and into the ash drop chamber 21. For example, the ash falling through holes 23 are stripe-shaped, and a plurality of stripe-shaped ash falling through holes 23 are arranged in parallel and at intervals.

In some embodiments, a swirling device (not shown) is provided within the flue gas chamber 22, which causes the flue gas entering the flue gas chamber 22 to swirl. Specifically, during the rotation and rising process of the flue gas in the flue gas chamber 22, the speed distribution characteristics of the peripheral high-speed area and the central low-speed area, and the distribution characteristics of the peripheral dust fly ash (solid particles) enrichment and the central dust (solid particles) sparseness are formed. That is, the flue gas can make most of the solid particles distributed on the peripheral side of the flue gas chamber 22 during the rotation and the moving speed is fast, so that the solid particles concentrated on the peripheral side of the flue gas chamber 22 can easily impact (extend in the up-down direction) the second housing 2 under the action of the centrifugal force and pass through the ash falling through hole 23 to be thrown into the ash falling chamber 21. In addition, in the low velocity region of the central region of the flue gas chamber 22, the solid particles will also be reduced due to the lower flue gas carrying capacity, and more solid particles will also move toward the ash discharge opening 14 and leave the flue gas chamber 22, thereby significantly improving the effect of the flue 100 in removing the solid particles from the flue gas.

The swirling device comprises at least one of a swirling vane and a deflector plate group. In particular, the swirling device may be a prior art flue-zoned mixer. For example, the flow deflecting devices in the flue zoning mixer each comprise a first flow deflecting plate group and a second flow deflecting plate group, wherein each flow deflecting plate in the first flow deflecting plate group and each flow deflecting plate in the second flow deflecting plate group are obliquely distributed, each flow deflecting plate in the first flow deflecting plate group is parallel to each other, each flow deflecting plate in the second flow deflecting plate group is parallel to each other, and the oblique direction of each flow deflecting plate in the first flow deflecting plate group is opposite to that of each flow deflecting plate in the second flow deflecting plate group. The flow deflecting device further comprises a first fixing rod and a second fixing rod, wherein the end portion of the first fixing rod and the end portion of the second fixing rod are fixed on the inner wall of the second shell 2, the first fixing rod sequentially penetrates through the flow deflecting plates in the first flow deflecting plate group, and the second fixing rod sequentially penetrates through the flow deflecting plates in the second flow deflecting plate group.

Alternatively, the swirling device may be a gas swirling device suitable for a flue gas mixer pipeline in the prior art, and the gas swirling device is provided with a plurality of swirling vanes so as to rotate the flue gas entering the flue gas chamber 22. The inclination angle of the swirl vanes is not less than 30 degrees and not more than 60 degrees.

As shown in fig. 2, in some instances, the flue gas chamber 22 includes a plurality of partitions 24, each partition 24 being in communication with the first inlet 12, the first outlet 13, and the ash discharge port 14, the partitions 24 being arranged in a horizontal orientation. The swirling device cooperates with the plurality of partitions 24 to impart a rotation to the flue gas entering the partitions 24. Thereby, the flue gas in each sector 24 of the flue gas chamber 22 can be made to rotate, so that the flue gas is uniformly mixed and solid particles are easily removed. For example, the swirling device is a flue partition mixer, and a flow deflecting device is arranged in each partition 24, so that the flue gas entering the partition 24 rotates, and the concentration of flue gas components in the partition can be uniformly mixed to facilitate denitration.

As shown in FIG. 2, in some embodiments, the plurality of partitions 24 are arranged side-by-side in a first horizontal direction. Specifically, in a cross section perpendicular to the extending direction (up-down direction) of the flue, the outer peripheral contour of the projection of the flue 100 (body 15) is generally rectangular, and the first horizontal direction may be the length direction of the rectangular projection of the flue 100, so that the plurality of partitions 24 are arranged along the length direction of the rectangular section of the flue 100, thereby facilitating the rotation of the flue gas of the partitions 24. The opposite rotation directions of the flue gases in two adjacent sectors 24 can prevent the flue gases in the (physically non-separated) adjacent sectors 24 from being mixed with each other and keep relatively independent, thereby facilitating the continuous flow of the rotating gas flow in the sectors 24 for removing the solid particles. The first horizontal direction may be a left-right direction. For example, the plurality of partitions 24 are arranged side by side in the left-right direction, and the rotation directions of the flue gas in two adjacent partitions 24 in the left-right direction are opposite.

In some embodiments, on a cross section perpendicular to the up-down direction, a projection of each partition 24 is one of a square, a circle, and a regular polygon. Thereby, the flue gas in the subareas 24 can be rotated conveniently, and the solid particles in each subarea 24 are easily thrown into the ash falling cavity 21.

In some embodiments, the ash drop through-hole 23 extends spirally in the extending direction of the second housing 2. Specifically, the second casing 2 includes a plurality of second sub-casings which are connected and define the ash falling through-holes 23 spirally extending in the extending direction of the second casing 2, so that the solid particles in the rotating flue gas easily pass through the ash falling through-holes 23. For example, the ash dropping through hole 23 extends spirally in the up-down direction, and the spiral direction of the ash dropping through hole 23 coincides with the rotation direction of the flue gas.

In some embodiments, the body 15 and the second housing 2 may be obliquely arranged annular housings.

In some embodiments, a plurality of partition boards (not shown in the drawings) are disposed in the second casing 2, the partition boards divide the flue gas cavity 22 into a plurality of partitions 24, the thickness direction of the partition boards is a horizontal direction, each partition board has a partition board cavity and a partition board through hole, the partition board cavity is communicated with the ash discharge port 14, the partition board through holes penetrate through the partition boards, and the partition board cavity is communicated with the flue gas cavity 22 through the partition board through holes. The partition plates can prevent the rotating smoke in the adjacent subareas 24 from influencing each other, thereby facilitating the rotation of the smoke. And the partition plate cavity is communicated with the flue gas cavity 22 through the partition plate through holes, namely the partition plate cavity is communicated with the subareas 24 through the partition plate through holes, so that the flue gas can be thrown into the partition plate cavity and then discharged out of the flue gas cavity 22.

The invention also provides a generator set which comprises an economizer, a denitration reactor 4 and a flue 100 according to the embodiment of the invention, wherein the outlet of the economizer is communicated with the first inlet 12 of the flue 100, and the inlet of the denitration reactor 4 is communicated with the first outlet 13 of the flue. Therefore, the solid particles in the flue gas from the economizer can be removed after the flue gas passes through the flue 100, so that the solid particles in the flue gas entering the denitration reactor 4 are less, the abrasion to the denitration reactor 4 can be reduced, and the service life of the denitration reactor 4 is prolonged.

Therefore, the generator set provided by the embodiment of the invention has the advantages that the flue 100 has a good effect of removing solid particles in flue gas, and the denitration reactor 4 has a long service life.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be interconnected within two elements or in a relationship where two elements interact with each other unless otherwise specifically limited. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although the above embodiments have been shown and described, it should be understood that they are exemplary and should not be construed as limiting the present invention, and that many changes, modifications, substitutions and alterations to the above embodiments may be made by those of ordinary skill in the art without departing from the scope of the present invention.

Claims (10)

1. A flue, comprising:

the first shell is provided with a flue cavity, a first inlet, a first outlet and an ash discharge port, wherein the first inlet, the first outlet and the ash discharge port are communicated with the flue cavity;

the second shell is located in the flue cavity, the first shell is sleeved on the outer side of the second shell, the first shell and the second shell are arranged at intervals, the distance between the inner wall surface of the first shell and the outer wall surface of the second shell is smaller than or equal to a preset value, an ash falling cavity is limited by the inner wall surface of the first shell and the outer wall surface of the second shell, an ash falling cavity is limited by the inner wall surface of the second shell, the ash falling cavity is communicated with the first inlet, the first outlet and the ash discharge port, the ash falling cavity is communicated with the ash discharge port, an ash falling through hole penetrating through the ash falling through hole is formed in the second shell, and the ash falling through hole is communicated with the ash falling cavity and the ash falling cavity.

2. The flue according to claim 1, wherein the first housing comprises a body, the body and the second housing are annular housings extending in an up-down direction, the body is sleeved outside the second housing and defines the ash falling cavity with the second housing, the first inlet is located below the first outlet, the ash discharge port is formed in the bottom of the body, the top of the ash falling cavity is closed, and the outlet of the ash falling cavity is formed in the bottom of the ash falling cavity and faces the ash discharge port.

3. The flue according to claim 1,

the ash falling through holes are in a strip shape or a block shape and are spaced;

or, the ash falling through hole extends spirally along the extending direction of the second shell.

4. The flue according to claim 2, wherein a distance between the first casing and the second casing in an inward and outward direction is 10 cm or less.

5. The flue according to claim 2 wherein a swirling device is disposed in the flue gas chamber, the swirling device swirling flue gas entering the flue gas chamber, the swirling device comprising at least one of a swirling vane and a set of deflecting plates.

6. The flue according to claim 5 wherein said flue gas chamber includes a plurality of sections, each of said sections communicating with said first inlet, said first outlet and said ash discharge port, said sections being arranged in a horizontal orientation, said swirling means cooperating with said plurality of sections to cause rotation of flue gas entering said sections.

7. The flue according to claim 6 wherein a plurality of said sections are juxtaposed in a first horizontal direction, the direction of rotation of the flue gas in adjacent two of said sections being opposite.

8. The flue according to claim 7, wherein a projection of each of the partitions on a cross section perpendicular to an up-down direction is one of a square, a circle, and a regular polygon.

9. The flue according to claim 6, wherein a plurality of partition plates are arranged in the second casing, the partition plates divide the flue gas cavity into a plurality of partitions, the thickness direction of the partition plates is a horizontal direction, each partition plate is provided with a partition plate cavity and a partition plate through hole, the partition plate cavity is communicated with the ash discharge port, the partition plate through hole penetrates through the partition plate, and the partition plate cavity is communicated with the flue gas cavity through the partition plate through hole.

10. A generator set, comprising:

a coal economizer;

a denitration reactor;

the flue as claimed in any one of claims 1 to 9, wherein the outlet of the economizer is communicated with the first inlet of the flue, and the inlet of the denitration reactor is communicated with the first outlet of the flue.

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