CN204438192U - A kind of nozzle and gas turbine - Google Patents

Abstract

The utility model relates to the technical field of power equipment, in particular to a nozzle and a gas turbine. The nozzle includes a central body, an annular wall and a swirl device; a peripheral mixing channel is formed between the annular wall and the central body, a central body mixing channel is opened inside the central body, and independent premixed fuel channels are also provided on the central body And the diffusion fuel channel, the pre-mixed fuel channel injects fuel to the center body mixing channel and the peripheral mixing channel respectively to form a fuel-air mixture, the diffusion fuel channel directly injects fuel to the flame cylinder axial direction, and finally forms a diffusion combustion in the middle at the outlet of the nozzle Both the flame and the inner and outer layers are in the flame form of a premixed combustion flame. Under the action of diffusion combustion, the flame stability and combustion efficiency of the nozzle are greatly improved under lower load; at the same time, due to the structural improvement mainly at the outlet of the nozzle, the structure can be easily processed and maintained.

Description

A nozzle and a gas turbine

technical field

The utility model relates to the technical field of power equipment, in particular to a nozzle and a gas turbine, in particular to a nozzle with an interlayer diffusion flame.

Background technique

With the energy shortage and the world's attention to environmental protection issues, countries have increasingly strict requirements on gas turbine combustor emissions and combustion efficiency. Generally, gas turbines are required to maintain a low level of combustion chamber emissions in the 50% and above load range. , while maintaining high combustion efficiency. In order to achieve the purpose of low emission, premixed combustion technology is widely used. Therefore, the nozzle needs to realize the pre-mixing of fuel and air, and form a fuel-air mixture at the outlet of the nozzle that is uniformly mixed and has a certain speed, and then enters the flame tube to participate in combustion.

Since the fuel injected from the nozzle burns in the form of a premixed flame in the combustion chamber, in order to achieve extremely low pollution emissions, the flame works near the combustible boundary. The stability of the flame is relatively difficult. The solution in the prior art is usually that the axial length of the center body is smaller than the length of the outer wall of the nozzle, so that the fuel-air mixture flows out of the annular premixing channel first to the downstream of the head end wall of the center body. The central area expands, forming a recirculation zone in the central area downstream of the end wall of the center body head, and then enters the flame tube and further expands in the flame tube, thereby forming a larger recirculation area in the flame tube for the stability of the premixed flame. However, these two recirculation areas are easily affected by other airflows in the flame tube. This method is simply to improve the stability of the premixed flame from the aerodynamic angle of forming a stable recirculation area. Due to the relatively high inlet pressure, inlet temperature and fuel-air mixture equivalent, the nozzle can easily achieve reliable flame stability and high combustion efficiency. The fuel-air mixture equivalent is relatively low, which is not conducive to the stable and efficient combustion of the premixed flame, which makes the premixed flame unstable or poor in stability and the risk of low combustion efficiency.

In order to improve the stability of the flame, in the existing patent document (CN1704574), the impingement air flow opposite to the main flow direction is produced near the center body of the nozzle outlet to form a recirculation vortex, which reduces the amount of air injected into the recirculation zone , thus reducing the jet velocity near the nozzle outlet and improving the flame stability. This method only improves the stability of the local recirculation zone from the perspective of aerodynamics, and only has a certain effect on the stability of the premixed flame, and due to the nature of premixed combustion, this method cannot reliably improve the flame stabilization performance of the nozzle , and it cannot guarantee that the premixed flame has higher combustion efficiency under lower load; in addition, from the perspective of processing technology, the structural processing and connection of the inner layer baffle of this premixed nozzle is relatively complicated, and it is not easy to maintain and replace .

Therefore, in view of the above deficiencies, there is a need for a nozzle and a gas turbine with an interlayer diffusion flame that can improve flame stability and combustion efficiency.

Utility model content

(1) Technical problems to be solved

The technical problem to be solved by the utility model is to provide a nozzle and a gas turbine. The nozzle has an interlayer diffusion flame, which can effectively improve the fire stability performance and combustion efficiency.

(2) Technical solution

In order to solve the above technical problems, the nozzle provided by the utility model includes a center body, an annular wall and a swirl device, the center body is provided with a center body mixing channel; the inlet end of the center body mixing channel is provided with a swirl orifice, The outlet end is provided with a head end wall; the annular wall is coaxially arranged on the periphery of the central body, and a peripheral mixing channel is formed between the annular wall and the annular wall; the swirl device is located on the peripheral mixing channel close to the central body One end of the inlet; the central body is provided with a premixed fuel passage and a diffusion fuel passage; the premixed fuel passage communicates with the central body mixing passage through the central body premixed fuel injection hole; the head end wall is provided with An annular fuel outlet facing the ignition area of the flame tube, the annular fuel outlet communicates with the diffusion fuel passage.

Wherein, the diffusion fuel channel communicates with the annular fuel outlet through the oil collecting chamber.

Wherein, a throttling hole is provided between the oil collecting chamber and the annular fuel outlet.

Wherein, the central body mixing channel is provided with a central body contraction section and a central body expansion section, and the central body expansion section is located downstream of the central body contraction section.

Wherein, one end of the central body close to the end wall of the head is provided with a center extracorporeal expansion section; the end wall of the head is provided with an end wall injection hole, and the end wall injection hole passes through the center extracorporeal expansion section and The peripheral mixing channel is connected.

Wherein, the center body premixed fuel injection hole and the end wall injection hole are straight holes or oblique holes.

Wherein, the axial position of the end wall of the head is located within the axial range of the annular wall.

Wherein, the swirl device includes swirl blades arranged along the circumference of the central body, the swirl blades are provided with blade inner passages, the blade inner passages are provided with blade premixed fuel injection holes, and the blade interiors are The channel communicates with the premixed fuel channel.

Wherein, a plurality of tangential holes are opened on the swirling orifice plate.

The utility model also provides a gas turbine, which includes the nozzle.

(3) Beneficial effects

The above-mentioned technical solution of the utility model has the following beneficial effects: the utility model provides a nozzle, by setting an independent fuel outlet on the end wall of the nozzle head, part of the fuel is directly injected into the flame tube for diffusion combustion, and finally forms a middle The interlayer is in the form of diffusion combustion flame, and the inner and outer layers are in the form of premixed combustion flame. The diffusion combustion flame in the middle layer of the nozzle outlet can greatly improve the flame stability performance of the nozzle and ensure high combustion efficiency. The nozzle has a simple structure, is easy to realize, and is not restricted by other parts of the combustion chamber, and has no problems such as matching.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment nozzle;

Fig. 2 is a partial enlarged schematic view of the outlet of the nozzle of the embodiment of the utility model;

Fig. 3 is the front schematic view of the outlet of the nozzle of the embodiment of the utility model;

Fig. 4 is the perspective view of the nozzle of the utility model embodiment;

Fig. 5 is a schematic diagram of the use state of the nozzle of the embodiment of the present invention.

Among them, 1: central body; 2: annular wall; 3: swirl device; 4: swirl blade; 5: head end wall; 6: swirl orifice; 7: tangential hole; 8: premixed fuel channel ;9: vane internal channel; 10: vane premixed fuel injection hole; 11: inner wall of premixed fuel channel; 12: center body premixed fuel injection hole; 13: diffusion fuel channel; 14: oil collection chamber; 15: node Orifice; 16: annular fuel outlet; 17: end wall injection hole; 18: expanding section outside the centrosome; 19: constricting section inside the centrosome; 20: expanding section inside the centrosome; 21: mixing channel throat of the centrosome; 22: centrosome Mixing channel; 23: Peripheral mixing channel; 24: Central premixed flame; 25: Intermediate interlayer diffusion flame; 26: Peripheral premixed flame.

Detailed ways

The implementation of the present utility model will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the utility model, but cannot be used to limit the scope of the utility model.

In the description of the present utility model, unless otherwise specified, the meaning of "multiple" is two or more; the terms "upper", "lower", "left", "right", "inner", "outer" ", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that unless otherwise specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or Integratively connected; it can be mechanically or electrically connected; it can be directly connected or indirectly connected through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model in specific situations.

As shown in Figures 1-5, the nozzle of this embodiment includes a central body 1, an annular wall 2 and a swirl device 3, and a central body mixing channel 22 is arranged in the central body 1; The orifice plate 6, the outlet end of the central body mixing channel 22 is provided with a head end wall 5; the annular wall 2 is coaxially arranged on the periphery of the central body 1, and a peripheral mixing channel 23 is formed between the annular wall 2 and the annular wall 2; The swirl device 3 is located at one end of the peripheral mixing passage 23 near the inlet of the central body 1, and is used to generate swirl air; and, the central body 1 is provided with an independent premixed fuel passage 8 and a diffusion fuel passage 13; the premixed fuel passage 8 is communicated with the central body mixing passage 22 through the central body premixed fuel injection hole 12; on the head end wall 5, an annular fuel outlet 16 facing the ignition area of the flame tube is provided, and the annular fuel outlet 16 communicates with the diffusion fuel passage 13, so that Part of the fuel is directly injected into the flame tube for diffusion combustion, and the inner and outer radial spaces of the fuel outlet of the diffusion combustion are the outlets of the fuel-air mixture, finally forming a form in which the interlayer is a diffusion combustion flame and the inner and outer layers are a premixed combustion flame. The diffusion combustion flame in the interlayer of the nozzle outlet can greatly improve the flame stability performance of the nozzle and ensure a high combustion efficiency.

As shown in FIG. 2 , the diffusion fuel channel 13 communicates with the annular fuel outlet 16 through the oil collecting chamber 14 . Wherein, the orientation of the annular fuel outlet 16 is the axial direction of the nozzle, that is, towards the ignition area of the flame tube. Moreover, an orifice 15 that can control the fuel flow is provided between the oil collecting chamber 14 and the annular fuel outlet 16 to reduce the fuel injection velocity and make the interlayer diffusion flame 25 more stable.

Moreover, a central body constriction section 19 and a central body expansion section 20 are provided on the central body mixing channel 22 , and the central body expansion section 20 is located downstream of the central body contraction section 19 . The constriction section 19 in the center body will increase the injection velocity of the fuel-air mixture, and reach the maximum at the throat 21 of the center body mixing channel. The center body mixing channel throat 21 can prevent the center premixed flame 24 from tempering into the center body mixing channel 22 The expansion section 20 in the central body guides the fuel-air mixture so that the fuel-air mixture is not easy to separate and is easily ignited by the interlayer diffusion flame 25 .

Simultaneously, one end near the head end wall 5 on the central body 1 is provided with a center extracorporeal expansion section 18; It communicates with the peripheral mixing channel 23 so that part of the fuel-air mixture can be injected from the end wall injection hole 17, which will have a certain cooling effect on the head end wall 6.

As shown in FIG. 3 and FIG. 4 , the center body premixed fuel injection hole 12 and the end wall injection hole 17 are straight holes or oblique holes. Wherein, the straight hole is a through hole opened along the axial direction, and the inclined hole is a through hole opened along the vector direction of the axial direction and the radial direction. Meanwhile, the center body premixed fuel injection hole 12 and the end wall injection hole 17 can also be used for The tangential hole for the fuel to rotate through, of course, can also be other types of holes, for example, tapered holes and the like.

In this embodiment, the axial position of the head end wall 5 is within the axial range of the annular wall 2 , that is, the head end wall 5 is within the covering range of the annular wall 2 .

Wherein, the swirl device 3 includes swirl vanes 4 arranged circumferentially along the central body 1, the swirl vanes 4 are provided with a vane internal channel 9, the vane internal channel 9 is provided with a vane premixed fuel injection hole 10, and the vane internal channel 9 communicates with the premixed fuel passage 8 .

Moreover, a plurality of tangential holes 7 are opened on the swirl orifice plate 6 for generating swirl.

In addition, the utility model provides a gas turbine, which includes the nozzle.

The working principle of the utility model is as follows: First, the external air enters the peripheral mixing channel 23 and the central body mixing channel 22 through the swirling device 3 and the swirling orifice 6 respectively, and the fuel enters the inside of the blade through the premixed fuel channel 8 respectively. Passage 9 and center body premixed fuel injection hole 12, a part of the fuel is injected into the peripheral mixing passage 23 through the vane premixed fuel injection hole 10 on the vane internal passage 9 and mixed with air, and the other part of fuel passes through the center body premixed fuel The injection hole 12 injects into the center body mixing channel 22 and mixes with air.

An independent diffusion fuel channel 13 is opened in the central body 1, an oil collecting chamber 14 is opened downstream of the diffusing fuel channel 13, and a throttling hole 15 is opened downstream of the oil collecting chamber 14, and an annular The fuel outlet 16 communicates with the diffusion fuel passage 13 through the orifice 15, so that the fuel can be directly injected into the flame tube to generate diffusion combustion, forming an interlayer diffusion flame 25; the downstream of the orifice 15 is provided with an annular fuel outlet 16 The purpose is to reduce the injection velocity of the fuel and make the interlayer diffusion flame 25 more stable.

The central body mixing channel 22 is provided with a constriction section 19 and an expansion section 20 in the center body, and the expansion section 20 is downstream of the contraction section 19 in the center body, that is, the center body mixing channel 22 is a contraction-expansion channel; 19. The central body mixing channel throat 21 is formed between the expansion sections 20 in the center body, and the fuel-air mixture injected from the center body mixing channel 22 is ignited by the interlayer diffusion flame 25 to form a center premixed flame 24; the center body mixing The constriction section 19 in the center body in the channel 22 will increase the injection velocity of the fuel-air mixture, and reach the maximum at the throat 21 of the center body mixing channel. 22 internal tempering; the expansion section 20 in the central body guides the fuel-air mixture so that the fuel-air mixture is not easy to separate and is easily ignited by the interlayer diffusion flame 25 . The fuel-air mixture injected by the peripheral mixing channel 23 is ignited by the interlayer diffusion flame 25 to form a peripheral premixed flame 26; the central body 1 is provided with a central external expansion section 18 upstream of the head end wall 6, which will increase the fuel-air mixture. The jet velocity can prevent the peripheral premixed flame 26 from flashing back into the peripheral mixing channel 23 .

The end wall 6 of the head is provided with an end wall injection hole 17, and the end wall injection hole 17 communicates with the peripheral mixing passage 23 through the central outer expansion section 18, and part of the fuel-air mixture is injected from the end wall injection hole 17, and the opposite head end Wall 6 has a certain cooling effect.

As shown in Figure 5, the final effect is that the middle of the nozzle outlet is a diffusion combustion flame, and the inner and outer layers are premixed combustion flames. Under the action of diffusion combustion, the flame stability and combustion efficiency of the nozzle are improved at a lower load. It has been greatly improved; with the increase of load, due to the increase of inlet temperature, inlet temperature and fuel-air mixture equivalence ratio, the stability and combustion efficiency of the premixed flame reach a higher level, and in order to achieve lower emissions At this time, the diffusion fuel passage 13 can be closed, only the premix fuel passage 8 supplies fuel, and the nozzle adopts the full premix combustion mode.

In summary, the utility model provides a nozzle. By setting an independent fuel outlet on the end wall of the nozzle head, part of the fuel is directly injected into the flame tube for diffusion combustion, and finally forms a middle interlayer as a diffusion combustion flame, inside and outside The layer is in the form of a premixed combustion flame, and the diffusion combustion flame in the middle layer of the nozzle outlet can greatly improve the flame stability performance of the nozzle and ensure high combustion efficiency. The nozzle has a simple structure, is easy to realize, and is not restricted by other parts of the combustion chamber, and has no problems such as matching.

The embodiments of the invention have been presented for purposes of illustration and description, but are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and changes will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to better illustrate the principle and practical application of the invention, and to enable those of ordinary skill in the art to understand the invention and design various embodiments with various modifications suitable for particular purposes.

Claims (10)

1. a nozzle, comprises centerbody (1), annular wall (2) and swirl-flow devices (3), is provided with centerbody hybrid channel (22) in described centerbody (1); The entrance point of described centerbody hybrid channel (22) is provided with eddy flow orifice plate (6), and the port of export is provided with head end wall (5); Described annular wall (2) is coaxially arranged on the periphery of centerbody (1), forms peripheral hybrid channel (23) between described annular wall (2) and annular wall (2); Described swirl-flow devices (3) is positioned at upper one end near centerbody (1) import, peripheral hybrid channel (23); It is characterized in that: described centerbody (1) is provided with premixed fuel passage (8) and diffused fuel passage (13); Described premixed fuel passage (8) is communicated with centerbody hybrid channel (22) by centerbody premixed fuel spray-hole (12); Described head end wall (5) is provided with and exports (16) towards the annular fuel of burner inner liner ignition zone, and described annular fuel outlet (16) is communicated with diffused fuel passage (13).

2. nozzle according to claim 1, is characterized in that, described diffused fuel passage (13) exports (16) by collection chamber (14) with annular fuel and is communicated with.

3. nozzle according to claim 2, is characterized in that, described collection chamber (14) and annular fuel export between (16) and be provided with throttle orifice (15).

4. nozzle according to claim 1, it is characterized in that, described centerbody hybrid channel (22) is provided with contraction section in centerbody (19) and centerbody intramedullary expansion section (20), and centerbody intramedullary expansion section (20) is positioned at the downstream of centerbody contraction section (19).

5. nozzle according to claim 1, is characterized in that, the upper one end near head end wall (5) of described centerbody (1) is provided with the outer expansion segment (18) of centerbody; Described head end wall (5) is provided with end wall spray-hole (17), and described end wall spray-hole (17) is communicated with peripheral hybrid channel (23) through the outer expansion segment (18) of described centerbody.

6. nozzle according to claim 5, is characterized in that, described centerbody premixed fuel spray-hole (12) and end wall spray-hole (17) are straight hole or inclined hole.

7. nozzle according to claim 1, is characterized in that, the axial location of described head end wall (5) is positioned at the axial range of annular wall (2).

8. nozzle according to claim 1, it is characterized in that, described swirl-flow devices (3) comprises the swirl vane (4) that centrally body (1) circumference is arranged, blade interior passage (9) is provided with in described swirl vane (4), described blade interior passage (9) is provided with blade premixed fuel spray-hole (10), and described blade interior passage (9) is communicated with premixed fuel passage (8).

9. nozzle according to claim 1, is characterized in that, described eddy flow orifice plate (6) offers multiple tangential hole (7).

10. a gas turbine, is characterized in that, comprises nozzle as claimed in any one of claims 1-9 wherein.