阅读说明：本技术 一种低污染燃烧室喷嘴结构及方法 (Low-pollution combustion chamber nozzle structure and method ) 是由 林俊光 孙士恩 汪玉明 林钢 秦刚华 鲍听 马聪 俞李斌 于 2021-10-08 设计创作，主要内容包括：本发明涉及低污染燃烧室喷嘴结构,包括喷嘴单元,每个独立的喷嘴单元主要由喷嘴本体、燃料腔体和空气板组成；喷嘴本体内设有燃料腔体,燃料腔体由喷嘴杆内腔体和喷嘴突扩内腔体相连组成；喷嘴本体外侧壁设有空气板,空气板由空气门洞和空气板壁面组成,空气板壁面上均匀分布有空气门洞；喷嘴本体上设有燃料孔,燃料孔位于空气门洞下游,并且燃料孔与空气门洞相对应；若干个喷嘴单元呈向心分布形式,组成多喷嘴结构。本发明的有益效果是：本发明采用多个喷嘴单元组合工作,在拆装上的难度会有所降低；当某个喷嘴单元出现故障时,可以只更换这一个喷嘴单元,对其他的喷嘴单元没有影响,维护成本大大减小。(The invention relates to a low-pollution combustion chamber nozzle structure, which comprises nozzle units, wherein each independent nozzle unit mainly comprises a nozzle body, a fuel cavity and an air plate; the nozzle body is internally provided with a fuel cavity, and the fuel cavity is formed by connecting an inner cavity of the nozzle rod and an inner cavity of the nozzle sudden expansion; the outer side wall of the nozzle body is provided with an air plate, the air plate consists of air door holes and an air plate wall surface, and the air door holes are uniformly distributed on the air plate wall surface; the nozzle body is provided with a fuel hole, the fuel hole is positioned at the downstream of the air door opening, and the fuel hole corresponds to the air door opening; the plurality of nozzle units are distributed in a centripetal mode to form a multi-nozzle structure. The invention has the beneficial effects that: the invention adopts a plurality of nozzle units to work in a combined way, so that the difficulty in disassembly and assembly can be reduced; when a certain nozzle unit breaks down, only the nozzle unit can be replaced, other nozzle units are not affected, and maintenance cost is greatly reduced.)

1. A low pollution combustor nozzle structure which characterized in that: the fuel nozzle comprises nozzle units, wherein each independent nozzle unit mainly comprises a nozzle body (1), a fuel cavity (2) and an air plate (3); a fuel cavity (2) is arranged in the nozzle body (1), and the fuel cavity (2) is formed by connecting a nozzle rod inner cavity (21) and a nozzle sudden-expansion inner cavity (22); the outer side wall of the nozzle body (1) is provided with an air plate (3), the air plate (3) consists of an air door hole (31) and an air plate wall surface (32), and the air door hole (31) is uniformly distributed on the air plate wall surface (32); the nozzle body (1) is provided with a fuel hole (15), the fuel hole (15) is positioned at the downstream of the air door opening (31), and the fuel hole (15) corresponds to the air door opening (31); the plurality of nozzle units are distributed in a centripetal mode to form a multi-nozzle structure.

2. The low pollution combustion chamber nozzle structure of claim 1, wherein: the nozzle body (1) is formed by sequentially connecting a nozzle rod wall surface (11), a nozzle sudden expansion wall surface (12), a nozzle cavity wall surface (13) and a nozzle end part wall surface (14).

3. The low pollution combustion chamber nozzle structure of claim 2, wherein: the nozzle rod wall surface (11) encloses and synthesizes a nozzle rod inner cavity (21), and the nozzle sudden expansion wall surface (12), the nozzle cavity wall surface (13) and the nozzle end wall surface (14) enclose and synthesize a nozzle sudden expansion inner cavity (22).

4. The low pollution combustion chamber nozzle structure of claim 2, wherein: the fuel holes (15) are located in the nozzle chamber wall (13).

5. The low pollution combustion chamber nozzle structure of claim 1, wherein: the air plates (3) are circularly arranged on the outer wall of the nozzle body (1) to form circular nozzle units, and 6-14 groups of air door holes (31) and fuel holes (15) are formed in one circular nozzle unit.

6. The low pollution combustion chamber nozzle structure of claim 5, wherein: the plurality of circular nozzle units are distributed in a centripetal mode to form a circular multi-nozzle structure.

7. The low pollution combustion chamber nozzle structure of claim 1, wherein: the air plates (3) are arranged on the outer wall of the nozzle body (1) in a hexagon to form hexagonal nozzle units, and one hexagonal nozzle unit is provided with 6 or 12 groups of air door holes (31) and fuel holes (15).

8. The low pollution combustion chamber nozzle structure of claim 7, wherein: the plurality of hexagonal nozzle units are distributed in a centripetal distribution mode to form a hexagonal multi-nozzle structure.

9. A method of operating a low pollution combustor nozzle arrangement as claimed in claim 1, comprising the steps of:

s1, the fuel enters the nozzle rod inner cavity (21) from the fuel inlet, then enters the nozzle sudden-expansion inner cavity (22) and then is divided into two parts, one part of the fuel impacts the end wall surface (14) of the nozzle along the linear flow, forms a backflow vortex in front of the end wall surface (14) of the nozzle and finally flows out of the nozzle structure from the fuel hole (15); another part directly flows out of the nozzle structure from the fuel hole (15);

s2, air enters the air door hole (31) from the air inlet, the flow rate is increased, the air and the fuel flowing out from the fuel hole (15) are mixed with each other, and the fuel speed direction is vertical to the air speed direction;

s3, after the fully mixed fuel gas is ignited by the igniter, a plurality of small independently dispersed flames are formed at the downstream of the fuel hole (15).

10. A combined operation method of the multi-nozzle structure of the low pollution combustion chamber as claimed in claim 1, wherein: at partial load, only one or more nozzle units are opened, and the opening number of the nozzle units is dynamically adjusted according to the requirement of the load of the combustion chamber, and the method comprises the following steps:

s1, the igniter is located at the circle center of the first layer of central nozzle unit, fuel is only supplied to the central nozzle unit after the igniter discharges and ignites, the central nozzle unit starts to be ignited, and the rotating speed of the gas turbine is gradually increased along with the increase of the power of the combustion chamber; when the rotating speed is increased to the rated rotating speed, the work and the power consumption of the gas turbine are mutually offset, the fuel flow is continuously increased, and the central nozzle unit is continuously kept to burn;

s2, when the work of the gas turbine is 25% of the rated load, opening the control valve of the nozzle unit of the second layer, and keeping the first layer and the second layer in a combustion state at the same time;

s3, when the work of the gas turbine is 50% of the rated load, opening the control valve of the nozzle unit in the third layer to make the nozzle units in the first layer, the second layer and the third layer keep a combustion state at the same time;

and S4, when the work of the gas turbine is 75% of the rated load, opening the control valve of the nozzle unit in the fourth layer to ensure that all the nozzle units simultaneously keep a combustion state.

Technical Field

The invention relates to a nozzle structure, in particular to a low-pollution combustion chamber nozzle structure and a method.

Background

With the shortage of energy and the worldwide emphasis on environmental issues, the requirements of various countries on the pollutant emission performance and combustion efficiency of gas turbines are becoming stricter, and the gas turbines are generally required to be in a load range of more than 50%, and the emission of combustion chambers can be maintained at a low level while maintaining high combustion efficiency. For gaseous fuels (e.g., methane), premixed combustion technology is widely used in order to achieve low emission levels. Although premixed combustion can reach a lower emission level, the mixed gas speed is easily lower than the flame speed due to various faults (nozzle blockage, dirt or design defects) in the running process of the unit, and the combustor is damaged due to backfire.

Patent CN106461211A discloses a combustion device of a gas turbine engine, comprising a nozzle and a burner based on MMX (Micro-Mix) combustion principle. It comprises a plurality of annular portions for fuel injection and annular portions for air guide, the fuel injection components and the air guide components being arranged alternately concentrically, the specific nozzle structure being shown in fig. 7 (which includes a fuel supply pipe 66, an intermediate annular duct 84, nozzle holes 36, nozzle holes 37, a fuel flow path 73). Wherein fuel (natural gas, hydrogen, etc.) enters the nozzle from the intermediate annular conduit 84 and is injected into the downstream liner through nozzle holes 36 and 37; air enters the downstream flame tube through air holes A distributed on the inner side and the outer side; the fuel and the air are mutually vertical and are fully mixed, and a plurality of independent small flame structures are formed at the downstream after the fuel and the air are ignited by an igniter, so that the flame temperature can be reduced, the residence time of the flame can be shortened, the NOx emission can be greatly reduced theoretically, and the occurrence of backfire can be avoided. The nozzle arrangement may be used for the combustion of a variety of fuels, such as natural gas, hydrogen, syngas, and the like.

However, the nozzle structures are all positioned on the annular part, and the nozzle structures are assembled in a whole ring, so that the nozzle structures are difficult to assemble and disassemble; when a certain nozzle is in fault or damaged, the whole annular part must be repaired and replaced together, and the maintenance cost is high.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a low-pollution combustion chamber nozzle structure and a method.

The low-pollution combustion chamber nozzle structure comprises nozzle units, wherein each independent nozzle unit mainly comprises a nozzle body, a fuel cavity and an air plate; the nozzle body is internally provided with a fuel cavity, and the fuel cavity is formed by connecting an inner cavity of the nozzle rod and an inner cavity of the nozzle sudden expansion; the outer side wall of the nozzle body is provided with an air plate, the air plate consists of air door holes and an air plate wall surface, and the air door holes are uniformly distributed on the air plate wall surface; the nozzle body is provided with a fuel hole, the fuel hole is positioned at the downstream of the air door opening, and the fuel hole corresponds to the air door opening; the plurality of nozzle units are distributed in a centripetal mode to form a multi-nozzle structure.

Preferably, the method comprises the following steps: the nozzle body is formed by connecting a nozzle rod wall surface, a nozzle sudden expansion wall surface, a nozzle cavity wall surface and a nozzle end wall surface in sequence.

Preferably, the method comprises the following steps: the wall surface of the nozzle rod is enclosed to form an inner cavity of the nozzle rod, and the wall surface of the nozzle sudden expansion, the wall surface of the nozzle cavity and the wall surface of the end part of the nozzle are enclosed to form an inner cavity of the nozzle sudden expansion.

Preferably, the method comprises the following steps: the fuel holes are located on the wall of the nozzle cavity.

Preferably, the method comprises the following steps: the air plates are circularly arranged on the outer wall of the nozzle body to form circular nozzle units, and 6-14 groups of air door holes and fuel holes are formed in one circular nozzle unit.

Preferably, the method comprises the following steps: the plurality of circular nozzle units are distributed in a centripetal mode to form a circular multi-nozzle structure.

Preferably, the method comprises the following steps: the air plates are arranged on the outer wall of the nozzle body in a hexagon shape to form hexagonal nozzle units, and 6 or 12 groups of air door holes and fuel holes are formed in one hexagonal nozzle unit.

Preferably, the method comprises the following steps: the plurality of hexagonal nozzle units are distributed in a centripetal distribution mode to form a hexagonal multi-nozzle structure.

The working method of the low-pollution combustion chamber nozzle structure comprises the following steps:

s1, enabling the fuel to enter the inner cavity of the nozzle rod from the fuel inlet, then entering the inner cavity of the nozzle sudden expansion and then dividing the inner cavity into two parts, enabling one part to impact the wall surface of the end part of the nozzle along the linear flow, forming a backflow vortex in front of the wall surface of the end part of the nozzle, and finally enabling the fuel to flow out of the nozzle structure from the fuel hole; another portion flows directly from the fuel orifice out of the nozzle structure;

s2, enabling air to enter the air door hole from the air inlet, increasing the flow speed, mixing the air with fuel flowing out of the fuel hole, and enabling the fuel speed direction to be vertical to the air speed direction;

and S3, igniting the fully mixed fuel gas by an igniter, and forming a plurality of small independently dispersed flames at the downstream of the fuel holes.

The multi-nozzle structure combined working method of the low-pollution combustion chamber nozzle structure only opens one or more nozzle units when in partial load, and the opening number of the nozzle units is dynamically adjusted according to the requirement of the combustion chamber load, and comprises the following steps:

s1, the igniter is located at the circle center of the first layer of central nozzle unit, fuel is only supplied to the central nozzle unit after the igniter discharges and ignites, the central nozzle unit starts to be ignited, and the rotating speed of the gas turbine is gradually increased along with the increase of the power of the combustion chamber; when the rotating speed is increased to the rated rotating speed, the work and the power consumption of the gas turbine are mutually offset, the fuel flow is continuously increased, and the central nozzle unit is continuously kept to burn;

s2, when the work of the gas turbine is 25% of the rated load, opening the control valve of the nozzle unit of the second layer, and keeping the first layer and the second layer in a combustion state at the same time;

s3, when the work of the gas turbine is 50% of the rated load, opening the control valve of the nozzle unit in the third layer to make the nozzle units in the first layer, the second layer and the third layer keep a combustion state at the same time;

and S4, when the work of the gas turbine is 75% of the rated load, opening the control valve of the nozzle unit in the fourth layer to ensure that all the nozzle units simultaneously keep a combustion state.

The invention has the beneficial effects that:

1. the invention adopts a plurality of nozzle units to work in a combined way, so that the difficulty in disassembly and assembly can be reduced; when a certain nozzle unit breaks down, only the nozzle unit can be replaced, other nozzle units are not affected, and maintenance cost is greatly reduced.

2. For the multi-nozzle unit combined working mode, when the load is partial, only one or more nozzle units can be opened, the opening number of the nozzle units can be dynamically adjusted according to the load requirement, the load adjustment difficulty of the combustion chamber is reduced, and the outlet temperature distribution of the combustion chamber is favorably not deteriorated on the premise of stable combustion.

Drawings

FIG. 1 is a schematic view of a low pollution combustor nozzle configuration;

FIG. 2 is a cross-sectional view of a low pollution combustor nozzle configuration;

FIG. 3 is a schematic view of a low pollution combustor nozzle configuration (circular embodiment);

FIG. 4 is a schematic view of a low pollution combustor nozzle configuration (hexagonal embodiment);

FIG. 5 is a schematic view of a low pollution combustor nozzle configuration (circular multi-nozzle embodiment);

FIG. 6 is a schematic view of a low pollution combustor nozzle configuration (hexagonal multi-nozzle embodiment);

fig. 7 is a schematic view of a nozzle structure in the related art.

Description of reference numerals: 1. a nozzle body; 11. the wall surface of the nozzle rod; 12. the nozzle expands the wall surface suddenly; 13. the wall surface of the nozzle cavity; 14. a nozzle tip wall surface; 15. a fuel hole; 2. a fuel cavity; 21. a nozzle stem internal cavity; 22. the nozzle expands the inner cavity; 3. an air plate; 31. an air door opening; 32. air panel wall.

Detailed Description

The present invention will be further described with reference to the following examples. The following examples are set forth merely to aid in the understanding of the invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The low pollution combustion chamber nozzle structure of this patent, the combustion chamber nozzle dismouting degree of difficulty, maintenance cost greatly reduced reduce the combustion chamber load and adjust the degree of difficulty, adapt to the combustion chamber power change.

Example one

The embodiment of the application provides a low pollution combustor nozzle structure, including nozzle body 1, fuel cavity 2 and air plate 3, form an independent nozzle unit, this nozzle unit can independent work, also can form many nozzle structures with other nozzle unit collaborative work. The nozzle unit can be independently disassembled and assembled, and any one or more nozzle units can be disassembled and assembled in the multi-nozzle structure. When a certain nozzle unit breaks down, the nozzle unit can be disassembled and maintained on the premise of not influencing other nozzle units, the operation is simple and convenient, and the maintenance cost is lower.

The nozzle body 1 is formed by sequentially connecting a nozzle rod wall surface 11, a nozzle sudden expansion wall surface 12, a nozzle cavity wall surface 13 and a nozzle end part wall surface 14; the fuel cavity 2 is formed by connecting a nozzle rod inner cavity 21 and a nozzle sudden-expansion inner cavity 22; the outer side wall of the nozzle cavity wall 13 is provided with a circle of air plates 3, each air plate 3 consists of an air door hole 31 and an air plate wall 32, and the air door holes 31 are uniformly distributed on the air plate wall 32; the nozzle chamber wall 13 is provided with fuel holes 15, the fuel holes 15 being located downstream of the air door openings 31, and the fuel holes 15 corresponding to the air door openings 31.

Example two

FIG. 2 is a cross-sectional view of a low pollution combustor nozzle configuration where fuel (natural gas/hydrogen/syngas of hydrogen and natural gas in any ratio) enters the nozzle stem inner cavity 21 from the fuel inlet, then enters the nozzle flare inner cavity 22 and is split into two portions, one of which impinges the nozzle tip wall 14 along a straight flow and forms a back vortex in front of the nozzle tip wall 14 and finally exits the nozzle configuration from the fuel orifice 15; another portion flows directly out of the nozzle structure from the fuel holes 15. Air enters the air door hole 31 from the air inlet, the flow velocity is increased, and the air is mixed with the fuel flowing out from the fuel hole 15, and the mixing between the fuel and the air can be enhanced due to the fact that the fuel velocity direction is perpendicular to the air velocity direction, and the micro-mixing effect is formed. After the fully mixed fuel gas is ignited by the igniter, a plurality of small flames which are independently dispersed are formed at the downstream of the fuel hole 15, the emission of NOx can be greatly reduced, and the phenomenon of backfire can be avoided because the fuel and the air are positioned in different channels.

EXAMPLE III

FIG. 3 is a circular distribution of a plurality of air door openings in a nozzle unit with one-to-one correspondence of air and fuel holes, the fuel holes being located downstream of the air holes. For a circular distribution, there are 6-14 sets of air door openings and fuel holes on one nozzle unit. The structural form and size of the fuel holes and air door openings are not specially limited, and the non-original structures capable of satisfying the above effects are all within the limited scope of the invention.

FIG. 5 is a circular multi-nozzle embodiment of a low pollution combustor nozzle configuration, in a centripetal distribution. The first layer is the central nozzle unit, the second layer is the outer 6 identical nozzle units, the third layer is 12 identical nozzle units, and the fourth layer is 18 identical nozzle units … …, and the specific number of layers is determined according to the size of the combustion chamber and the energy density.

Example four

FIG. 4 is a hexagonal pattern of multiple air door openings in a nozzle unit with 6 or 12 sets of air and fuel holes in a nozzle unit. The structural form and size of the fuel holes and air door openings are not specially limited, and the non-original structures capable of satisfying the above effects are all within the limited scope of the invention.

FIG. 6 is a hexagonal multi-nozzle embodiment of a low pollution combustor nozzle configuration, in a centripetal distribution. The first layer is the central nozzle unit, the second layer is the outer 6 identical nozzle units, the third layer is 12 identical nozzle units, and the fourth layer is 18 identical nozzle units … …, and the specific number of layers is determined according to the size of the combustion chamber and the energy density.

EXAMPLE five

For the multi-nozzle unit combination working mode, only one or more nozzle units can be opened at partial load, and the opening number of the nozzle units can be dynamically adjusted according to the requirement of the load of the combustion chamber. For example, an igniter (not shown) is located at the center of the center nozzle unit in the first layer, after the igniter is ignited by discharging, only the center nozzle unit is supplied with fuel, the center nozzle unit starts to be ignited, and the power of the combustion chamber is gradually increased with the increase of the fuel, so that the rotation speed of the gas turbine is gradually increased. When the rotating speed is increased to the rated rotating speed, the work and the power consumption of the gas turbine are just offset, the fuel flow is continuously increased, and the central nozzle unit is continuously kept burning. When the work of the gas turbine is 25% of the rated load, opening a control valve of the nozzle unit of the second layer, and enabling the nozzle units of the first layer and the second layer to simultaneously keep a combustion state; when the work of the gas turbine is 50% of the rated load, opening a control valve of a nozzle unit on the third layer, and enabling the nozzle units on the first layer, the second layer and the third layer to simultaneously keep a combustion state; when the work of the gas turbine is 75% of the rated load, the control valve of the nozzle unit in the fourth layer is opened, so that all the nozzle units are kept in a combustion state at the same time. Through the change of the opening number of the nozzles, an effective grading strategy can be formulated to reduce the load regulation difficulty of the combustion chamber, so that the combustion chamber can be ensured to be stably combusted under different loads, and lower pollutant emission and better outlet temperature distribution can be kept.