CN106838905A - Nozzle, nozzle array and burner with point shape blade - Google Patents

Abstract

The invention provides a nozzle with fractal blades, the inner cylinder and the outer cylinder are coaxially arranged, the inner cylinder surrounds the inner flow channel, and the outer layer is formed between the inner cylinder and the outer cylinder The flow channel, the fractal blade is sandwiched between the inner cylinder and the outer cylinder; the combustible mixture enters the inner flow channel and the outer flow channel, and under the action of the fractal blade, the combustible mixture in the outer flow channel simultaneously It moves in the axial and circumferential directions, and is ejected after merging with the combustible mixture in the inner channel. The nozzle of the present invention has fractal blades, which is beneficial to improve the swirling capacity, stability and combustion efficiency of the nozzle, restrain flow separation on the fractal blades, and reduce clogging and flow loss.

Description

Nozzles, nozzle arrays and burners with fractal blades

technical field

The invention relates to the field of combustion devices, especially a nozzle that can improve the efficiency and stability of the burner, widen the tempering margin, and reduce pollutant discharge, which is especially suitable for gas turbines, industrial burners, heaters, heating furnaces, etc. .

Background technique

Gas turbines are widely used in electric power, aviation, petrochemical and other industries due to their small size and large output power. Due to the energy crisis and environmental deterioration, it is urgent to develop high-efficiency and clean combustion chambers, which are required to have the characteristics of reliable ignition, stable combustion, high efficiency and low emissions. At present, the problem of environmental pollution in our country is very serious, and it is very urgent to develop clean combustion technology of gas turbines. Gas turbine manufacturers have developed a variety of clean combustion technologies, such as lean premixed combustion technology, dilute-phase premixed pre-evaporation technology, lean oil direct injection technology, and catalytic combustion technology. Although these technologies can effectively reduce pollutant emissions, they are all Faced with the problem of unstable combustion, and this burner has a complex structure and many parts. Other industrial burners face similar problems.

Therefore, there is an urgent need for a combustion device with a simple and compact structure, fewer parts, stable combustion, and low pollutant emissions.

Contents of the invention

(1) Technical problems to be solved

In order to solve the above-mentioned problems in the prior art, the present invention provides a nozzle with fractal blades, a nozzle array and a burner.

(2) Technical solution

The invention provides a nozzle with fractal blades, comprising an inner cylinder, an outer cylinder and fractal blades, wherein the inner cylinder and the outer cylinder are arranged coaxially, and the inner cylinder surrounds An inner flow channel is formed, an outer flow channel is formed between the inner cylinder and the outer cylinder, and the fractal blade is interposed between the inner cylinder and the outer cylinder; the combustible mixture enters the The inner layer flow channel and the outer layer flow channel, under the action of the fractal blade, the combustible mixture in the outer layer flow channel moves along the axial direction and the circumferential direction at the same time, and merges with the combustible mixture in the inner layer flow channel After squirting.

Preferably, the fractal blades include multi-stage fractal blades distributed from upstream to downstream, each stage of fractal blades includes a plurality of blades, and the blades have an inclination angle relative to the axial direction.

Preferably, the number of said multi-level fractal blades increases according to the law of ^2n-1 times, and each blade of the upper-level fractal blade corresponds to two blades of the lower-level fractal blade, and the two blades of the lower-level fractal blade The blades are symmetrically arranged on both sides of the blade of the upper-level fractal blade.

Preferably, it also includes: a mesh plate, which is arranged in the inner layer flow channel, and the combustible mixture enters the inner layer flow channel through the mesh plate.

Preferably, the method further includes: coating the fractal blade, the mesh plate and the inner cylinder with a catalyst coating.

Preferably, the upstream end of the blade is modified into a dovetail shape, a zigzag shape, an arc shape or multiple arc shapes.

Preferably, the upstream section of the outer cylinder is a hollow cavity; the fractal blade is a hollow structure, forming an internal fuel channel, and the trailing edge and/or leading edge of the fractal blade is provided with a first fuel injection hole , which is connected to the side opening of the inner wall of the hollow cavity of the outer cylinder; the position corresponding to the side opening of the fractal blade on the inner wall of the hollow cavity of the outer cylinder also has an opening, and the hollow cavity communicates with the internal fuel channel of the fractal blade; fuel or air It enters the hollow cavity, then enters the internal fuel channel of the fractal blade, and is injected into the outer flow channel by the first fuel injection hole of the fractal blade, and is mixed with the air or fuel entering the outer flow channel to form a combustible mixture.

Preferably, the side of the fractal blade connected to the inner cylinder is provided with a second fuel injection hole; the inner cylinder is provided with a through hole at a position corresponding to the second fuel injection hole, and through the second fuel injection hole and the through hole, The internal fuel channel of the fractal blade communicates with the inner flow channel; fuel or air enters the internal fuel channel of the fractal blade through the hollow cavity, and a part of the fuel or air is injected from the first fuel injection hole to the outer flow channel, and enters the outer flow channel. The air or fuel in the inner channel is mixed to form a combustible mixture, and another part of fuel or air enters the inner channel through the second fuel injection hole, and is mixed with the air or fuel entering the inner channel to form a combustible mixture.

The present invention also provides a nozzle array, including a plurality of any one of the above nozzles, wherein the nozzle array is a circular array, and the circular array includes P rings of nozzles, and each ring of nozzles includes Q nozzles, wherein 1 ≤P, Q≤100; or, the nozzle array is a rectangular array, the rectangular array includes P rows of nozzles, each row of nozzles includes Q nozzles, where 1≤P, Q≤100.

The present invention also provides a burner, which includes any one of the above-mentioned nozzles, or the above-mentioned nozzle array.

(3) Beneficial effects

As can be seen from the above technical solutions, the nozzle with fractal blades, nozzle array and burner of the present invention have the following beneficial effects:

(1) The number of fractal blades at each stage along the axial direction increases gradually according to the law of 2 ^n-1 times, and the fractal blades of the next stage are symmetrically arranged on both sides of the fractal blades of the previous stage. The fractal blades of this structure are conducive to improving the The swirling ability, stability and combustion efficiency of the nozzle suppresses flow separation on fractal blades, reduces clogging and flow loss;

(2) The combustible mixture in the outer channel flows through the fractal blades to generate centrifugal force. Under the action of the centrifugal force, the combustible mixture is no longer bound by the outer cylinder when it leaves the nozzle outlet, and the fluid movement is expanding. The fluid velocity near the axis is reduced and even backflow occurs, thereby improving the stability of flame combustion.

(3) The combustible mixture enters the inner flow channel through the mesh plate, and the mesh plate can control the fluid flow through the inner cylinder, and can also increase the turbulence of the fluid;

(4) Catalyst coatings are coated on fractal blades, mesh plates and inner cylinders. Catalyst coatings can reduce the activation energy of the reaction, enable combustion to proceed at lower temperatures and concentrations, and reduce emissions of combustion pollutants;

(5) The fuel enters the internal fuel channel of the fractal blade through the hollow cavity, a part of the fuel is injected from the first fuel injection hole to the outer flow channel, and mixed with the air entering the outer flow channel to form a combustible mixture, and the other part of the fuel passes through the first fuel injection hole. The second fuel injection hole enters the inner layer flow channel, and the air entering the inner layer flow channel is mixed to form a combustible mixture, which further improves the swirling efficiency of the nozzle and the uniformity of mixing.

Description of drawings

Fig. 1 is a schematic structural view of a nozzle with fractal blades according to a first embodiment of the present invention;

Fig. 2 is a three-dimensional schematic view of the nozzle shown in Fig. 1 omitting the outer cylinder;

Fig. 3 is the schematic diagram that blade inclination angle is positive;

Fig. 4 is the schematic diagram that blade inclination angle is negative;

Figure 5 is a schematic diagram of the size of the nozzle;

6 is a top view of a nozzle with fractal blades according to a second embodiment of the present invention;

Fig. 7 is a three-dimensional schematic diagram of the nozzle shown in Fig. 6 omitting the outer cylinder;

Fig. 8 is a schematic structural diagram of a nozzle with fractal blades according to a second embodiment of the present invention;

FIG. 9 is a schematic diagram of fractal blades of the nozzle shown in FIG. 8 .

【Symbol Description】

10-outer cylinder; 11-hollow cavity;

20-inner cylinder;

30-fractal blade; 31-first-level fractal blade; 32-second-level fractal blade; 33-third-level fractal; 34-internal fuel channel; 35-first fuel injection hole; 36-second fuel injection hole;

40-mesh plate;

A-inclination angle; B-the distance from the outlet end of the inner cylinder to the outlet of the nozzle; C-the distance from the downstream end of the last fractal blade to the outlet end of the inner cylinder.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

As shown in Figures 1 and 2, the nozzle with fractal blades according to the first embodiment of the present invention includes an inner cylinder 20, an outer cylinder 10, a mesh plate 40 and a fractal blade 30, wherein the inner cylinder 20 and the outer cylinder 10 are coaxially arranged, the inner cylinder 20 encloses the inner flow channel, the mesh plate 40 is arranged in the inner flow channel and is located at the inlet end of the inner cylinder 20, the inner cylinder 20 and An outer flow channel is formed between the outer cylinders 10 , and the fractal blades 30 are located in the outer flow channel and sandwiched between the inner cylinder 20 and the outer cylinder 10 .

As shown in Figure 2, the fractal blade 30 of this embodiment includes three-stage fractal blades distributed along the axial direction of the nozzle. Fractal blades 33, the first stage fractal blade 31 is close to the inlet end of the outer layer flow channel, and the third stage fractal blade 33 is close to the outlet end of the outer layer flow channel.

The second fractal blade 32 is located in the downstream direction of the first fractal blade 31, and each blade of the first fractal blade 31 corresponds to two blades of the second fractal blade 32, and the two blades of the second fractal blade Symmetrically arranged on both sides of the first-level fractal blade, the number of first-level fractal blades 31 is three, and the number of second-level fractal blades is six.

The third stage fractal blade 33 is positioned at the downstream direction of the second stage fractal blade 32, and each blade of the second stage fractal blade corresponds to two blades of the third stage fractal blade, and the two blades of the third stage fractal blade are arranged symmetrically On both sides of the blade of the second-level fractal blade, there are 12 third-level fractal blades. The number of fractal blades at each level along the axial direction gradually increases according to the law of 2 ^n-1 times, that is, if the number of first-level fractal leaves is X, the number of second-level fractal leaves is 2X, and the number of third-level fractal leaves is 4X , the number of fractal blades at the nth level is 2 ^n-1 X.

Each stage of fractal blades is arranged in the outer flow path between the inner cylinder 20 and the outer cylinder 10 along the circumferential direction, and the fractal blades 30 have a certain inclination angle relative to the axial direction.

According to the fractal law of the nozzle with the above structure, on the one hand, the number of fractal blades at each stage along the axial direction gradually increases according to the law of 2 ^{n -1} times; on the other hand, the fractal blades of the next stage are arranged symmetrically on the On both sides of the blade, the fractal blade of this structure is beneficial to improve the swirling capacity, stability and combustion efficiency of the nozzle, suppress flow separation on the fractal blade, reduce clogging and flow loss.

In this embodiment, the fuel and air have been evenly mixed before entering the nozzle to form a combustible mixture. The combustible mixture enters from the nozzle inlet, and part of the combustible mixture enters the inner channel through the mesh plate, and the other part enters the outer channel. The function of the fractal blade is to make the passing fluid move in the circumferential direction while moving in the axial direction. The combustible mixture in the outer flow channel flows through the fractal blades and merges with the combustible mixture flowing out of the inner flow channel, and is sprayed out from the nozzle outlet. Since the combustible mixture in the outer flow channel flows through the fractal blades to generate centrifugal force, under the action of the centrifugal force, the combustible mixture is no longer bound by the outer cylinder when it leaves the nozzle outlet, and the fluid movement is expanding, near the central axis of the nozzle outlet. The fluid velocity is reduced or even reflux occurs, which improves the stability of flame combustion.

In this embodiment, the fractal blade 30 is a solid blade; the fractal blade 30 can be a straight blade as shown in Fig. 2 , the straight blade is easy to process, and the manufacturing cost is low; it can also be a curved blade, and the curved blade can ensure the required air intake at the same time Angle and air outlet angle; the length of each fractal blade can be the same or different, preferably from the upstream to the downstream direction, the length of the fractal blade gradually increases; the thickness of the fractal blade can be uniform, which is convenient for processing, and can also be made into different thicknesses Streamlined, which can reduce flow loss; the height of each stage of fractal blades can be the same or different, preferably the same height, and the height refers to the length of the fractal blades extending radially along the nozzle. The upstream end of the fractal blade can also be modified. The upstream end can be dovetail-shaped, which can further enhance the swirl effect. Further, the upstream end can also be zigzag, arc-shaped, or multi-arc.

Although the present embodiment includes three levels of fractal blades, the present invention is not limited thereto. The number of stages of fractal blades may be 1-100, and the number of fractal blades per level is 1-100.

Part of the combustible mixture enters the inner flow channel through the mesh plate, and the mesh plate can control the fluid flow through the inner cylinder 20, and can also increase the turbulence of the fluid.

The ratio of the opening area of the mesh plate to the area of the mesh plate is 0-100%, that is to say, the mesh plate 40 can not be opened, and the ratio of the opening area of the mesh plate to the area of the mesh plate is 0 ; The mesh plate 40 can be completely perforated, which is equivalent to not setting a mesh plate, and the ratio of the area of the holes on the mesh plate to the area of the mesh plate is 100%. Preferably, the ratio of the area of the holes on the mesh plate to the area of the mesh plate is 40%-80%. The diameter of the hole of the mesh plate is 0.1-10mm, and the size of the hole can be the same or different; the shape of the hole can be circular, oval, triangular, polygonal or a combination of these shapes.

Please refer to Figure 3 and Figure 4 to illustrate the inclination angle of the fractal blade. The inclination angle A of the fractal blade is -90° to 90°. The inclination angle A of the fractal blade in Fig. 3 is 0 to 90°. A is 0° to -90°.

Please refer to Fig. 5, the distance B from the outlet end of the inner cylinder to the outlet of the nozzle is 0-1000mm; the distance C from the downstream end of the last stage fractal blade to the outlet end of the inner cylinder is 0-1000mm. Preferably, the distance B from the outlet end of the inner cylinder to the outlet of the nozzle is 1-5 times the diameter of the outer cylinder, and the distance C from the downstream end of the last stage fractal blade to the outlet end of the inner cylinder is the diameter of the outer cylinder 0.1-1 times.

In this embodiment, the catalyst coating is coated on the fractal blade 30 , the mesh plate 40 and the inner cylinder 20 . The catalyst coating can reduce the activation energy of the reaction, so that the combustion can be carried out at a lower temperature and concentration, and can reduce the emission of combustion pollutants.

For the purpose of brief description of the nozzle with fractal blades in the second embodiment of the present invention, any technical features described in the above-mentioned first embodiment that can be used in the same way are incorporated here, and the same description does not need to be repeated.

The nozzle of present embodiment, referring to Fig. 6, Fig. 7, the upstream section of outer layer cylinder is a hollow cavity 11, and fractal vane 30 is a hollow structure, forms an internal fuel channel 34, and the trailing edge of fractal vane 30 (i.e. downstream End face) has the first fuel injection hole 35, and it connects the side opening of the inner wall of the hollow cavity of the outer layer cylinder, and the position corresponding to the inner wall of the hollow cavity of the outer layer cylinder and the side opening of the fractal blade also has an opening, and the hollow cavity 11 and The internal fuel channels 34 of the fractal vanes communicate.

In the nozzle of this embodiment, the fuel enters the hollow cavity, then enters the internal fuel channel of the fractal blade, and is sprayed to the outer flow channel by the first fuel injection hole of the fractal blade, and is mixed with the air entering the outer flow channel to form a combustible mixture. The staggered arrangement of fractal blades is beneficial to the uniform mixing of fuel and air injected from the trailing edge of the fractal blades, and improves the swirl efficiency and mixing uniformity of the jet group.

Wherein, the leading edge (that is, the upstream end surface) of the fractal blade 30 may also be provided with the first fuel injection hole, or the trailing edge and the leading edge may be provided with the first fuel injection hole at the same time, which is beneficial to further improve the uniformity of mixing.

In addition, the input of fuel and air can be interchanged, that is, air can also enter the hollow cavity, and fuel can enter the outer flow channel.

Further, referring to Fig. 8 and Fig. 9, the side of the fractal blade 30 connected to the inner cylinder is also provided with a second fuel injection hole 36, and the position corresponding to the fuel injection hole on the side of the fractal blade is also provided with a through hole in the inner cylinder 20 , through the second fuel injection hole 36 and the through hole, the internal fuel channel 34 of the fractal blade communicates with the inner flow channel, and the mesh plate 40 is arranged downstream of the trailing edge of the last stage of the fractal blade.

The fuel enters the internal fuel channel of the fractal blade through the hollow cavity, a part of the fuel is injected from the first fuel injection hole to the outer channel, and mixed with the air entering the outer channel to form a combustible mixture, and the other part of the fuel is injected through the second fuel The holes enter the inner layer flow channel, and the air entering the inner layer flow channel is mixed to form a combustible mixture, which further improves the swirling efficiency of the nozzle and the uniformity of mixing.

The third embodiment of the present invention provides a nozzle array, which includes a plurality of nozzles with fractal blades described in any one of the above embodiments.

Wherein, the nozzle array is a circular array, and the circular array includes P rings of nozzles, and each ring of nozzles includes Q nozzles, where 1≤P, Q≤100.

Wherein, the nozzle array is a rectangular array, the rectangular array includes P rows of nozzles, each row of nozzles includes Q nozzles, where 1≤P, Q≤100.

The fourth embodiment of the present invention provides a burner, which includes the nozzle with fractal vanes or the nozzle array described in any one of the above embodiments.

So far, the present embodiment has been described in detail with reference to the drawings. Based on the above description, those skilled in the art should have a clear understanding of the nozzle with fractal blades, nozzle array and burner of the present invention.

It should be noted that, in the accompanying drawings or in the text of the specification, implementations that are not shown or described are forms known to those of ordinary skill in the art, and are not described in detail. In addition, the above definition of each element is not limited to the various specific structures, shapes or methods mentioned in the embodiments, and those skilled in the art can easily modify or replace them, for example:

(1) The directional terms mentioned in the embodiments, such as "up", "down", "front", "back", "left", "right", etc., are only referring to the directions of the drawings, and are not used to limit The protection scope of the present invention;

(2) The above embodiments can be mixed and matched with each other or with other embodiments based on design and reliability considerations, that is, technical features in different embodiments can be freely combined to form more embodiments.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A nozzle with fractal blades is characterized in that it comprises an inner cylinder, an outer cylinder and a fractal blade, wherein, The inner cylinder and the outer cylinder are arranged coaxially, the inner cylinder encloses an inner flow channel, an outer flow channel is formed between the inner cylinder and the outer cylinder, and the fractal The blades are sandwiched between the inner cylinder and the outer cylinder; The combustible mixture enters the inner flow channel and the outer flow channel, and under the action of the fractal vanes, the combustible mixture in the outer flow channel moves along the axial direction and the circumferential direction at the same time, and is connected with the inner flow channel The combustible mixture is sprayed out. 2. The nozzle according to claim 1, wherein the fractal blades comprise multistage fractal blades distributed from upstream to downstream direction, each stage of fractal blades comprises a plurality of blades, and the blades have inclination. 3. nozzle as claimed in claim 2, is characterized in that, the number of described multistage fractal blade increases according to the law of ^2n-1 times, and each blade of upper level fractal blade corresponds to two of next level fractal blades. The two blades of the next level of fractal blades are symmetrically arranged on both sides of the blades of the upper level of fractal blades. 4. The nozzle according to claim 1, further comprising: a mesh plate, which is arranged in the inner flow channel, and the combustible mixture enters the inner flow channel through the mesh plate. 5. The nozzle according to claim 4, further comprising: a catalyst coating is coated on the fractal blade, the mesh plate and the inner cylinder. 6 . The nozzle according to claim 3 , wherein the upstream end of the vane is modified into a dovetail shape, a zigzag shape, an arc shape or multiple arc shapes. 7. The nozzle of claim 1, wherein: The upstream section of the outer cylinder is a hollow cavity; The fractal blade is a hollow structure, forming an internal fuel passage, and the trailing edge and/or leading edge of the fractal blade has a first fuel injection hole, which is connected to the side opening of the inner wall of the hollow cavity of the outer cylinder; There is also an opening at the position where the inner wall of the hollow cavity of the outer cylinder corresponds to the side opening of the fractal blade, and the hollow cavity communicates with the internal fuel channel of the fractal blade; Fuel or air enters the hollow cavity, then enters the internal fuel channel of the fractal vane, and is injected from the first fuel injection hole of the fractal vane to the outer flow channel, and is mixed with the air or fuel entering the outer flow channel to form a combustible mixture. 8. The nozzle of claim 7, wherein: The side of the fractal blade connected to the inner cylinder is provided with a second fuel injection hole; A through hole is opened at the position corresponding to the inner cylinder and the second fuel injection hole, and the internal fuel channel of the fractal blade communicates with the inner flow channel through the second fuel injection hole and the through hole; Fuel or air enters the internal fuel channel of the fractal blade through the hollow cavity, a part of the fuel or air is injected from the first fuel injection hole to the outer channel, and mixed with the air or fuel entering the outer channel to form a combustible mixture, the other part Fuel or air enters the inner channel through the second fuel injection hole, and is mixed with the air or fuel entering the inner channel to form a combustible mixture. 9. A nozzle array, characterized in that it comprises a plurality of nozzles according to any one of claims 1 to 8, wherein, The nozzle array is a circular array, the circular array includes P rings of nozzles, and each ring of nozzles includes Q nozzles, where 1≤P, Q≤100; or, The nozzle array is a rectangular array, the rectangular array includes P rows of nozzles, each row of nozzles includes Q nozzles, where 1≤P, Q≤100. 10. A burner, characterized in that it comprises the nozzle according to any one of claims 1-8, or the nozzle array according to claim 9.