Disclosure of Invention
It is an object of the present invention to provide a coaxial staged gas fuel combustor head for a low emission gas turbine engine.
The purpose of the invention is realized by the following technical scheme: comprises an on-duty fuel flow path 5, a first stage hub 14, a second stage hub 24, a first stage fuel conduit 61 and a second stage fuel conduit 71; the inner side space of the inner wall of the first-stage hub 14 consists of a first-stage straight premixing channel 1 and a first-stage tapered mixing channel 3, the front end of the first-stage tapered mixing channel 3 is communicated with the first-stage straight premixing channel 1, and the tail end of the first-stage tapered mixing channel 3 is provided with a first-stage venturi 31; the inner side space of the inner wall of the second-stage hub 24 consists of a second-stage straight premixing channel 2 and a second-stage tapered mixing channel 4, the front end of the second-stage tapered mixing channel 4 is communicated with the second-stage straight premixing channel 2, and the tail end of the second-stage tapered mixing channel 4 is provided with a second-stage venturi 41; the duty-stage fuel flow path comprises a duty-stage fuel conduit 51 and a central blunt body 52; the central blunt body 52 is arranged in the first-stage straight premixing channel 1, and a ring of first swirl blades 13 are arranged between the central blunt body 52 and the first-stage hub 14; a first-stage fuel cavity 62 is arranged between the inner wall and the outer wall of the first-stage hub 14, first-stage fuel jet holes 63 are uniformly distributed on the surface of the inner wall of the first-stage hub 14, and the first-stage fuel jet holes 63 are communicated with the first-stage fuel cavity 62; the second-stage hub 24 is integrally positioned on the outer side of the outer wall of the first-stage hub 14, a circle of second swirl blades 23 are arranged between the first-stage hub 14 and the second-stage hub 24, the second swirl blades 23 are all positioned in the second-stage straight premixing channel 2, a swirl blade fuel cavity 73 is arranged inside the second swirl blades 23, a second-stage fuel jet hole 74 is formed in the surface of each second swirl blade 23, and the second-stage fuel jet hole 74 is communicated with the second-stage tapered mixing channel 4; a second-stage fuel cavity 72 is arranged between the inner wall and the outer wall of the second-stage hub 24; the second stage fuel conduit 71 is integrally positioned outside the outer wall of the second stage hub 24, and the second stage fuel conduit 71 is communicated with the second stage fuel cavity 72 through a fuel conduit; the first stage fuel conduit 61 is arranged in front of the head end of the first stage hub 14, and the first stage fuel conduit 61 is communicated with the first stage fuel cavity 62 through a fuel branch; one end of the duty-level fuel conduit 51 is connected with the front end of the central blunt body 52, and the other end extends out of the bottom of the first-level fuel conduit 61; the central blunt body 52 is internally provided with an on-duty fuel cavity 53, an on-duty fuel jet hole 54 is formed along the slope surface and the end surface of the central blunt body 52, and the on-duty fuel jet hole 54 is communicated with the first-stage tapered mixing channel 3.
The present invention may further comprise:
the outlet end surface of the first-stage venturi 31 is flush with the throat part of the second-stage venturi 41.
The quantity of the on-duty fuel jet holes 54 formed in the slope surface and the end surface of the central blunt body 52 is the same as that of the first swirl vanes 13.
The first swirl vanes 13 and the second swirl vanes 23 are lossless straight vanes, the swirl angle of the vanes is 30-60 degrees, and the number of the vanes is 6-12.
The invention has the beneficial effects that:
the integrated venturi combined with the tapered mixing section at the tail end of the head of the combustion chamber can effectively lift the flame so as to avoid backfire, and purge air does not need to be arranged or class-wide diffusion fuel does not need to be opened under high working conditions; the center class and the first-stage fuel pipe form a partial sleeve form, so that disturbance to incoming flow air is reduced, and the air quantity distribution of flow passages among the blades is uniform; the second-stage fuel pipe is arranged outside the second-stage hub, so that the influence of the fuel pipe on the air intake of the second stage is reduced; the swirling air and the fuel are premixed in the straight premixing channel respectively and then enter the tapered mixing channel to be mixed, so that the fuel is mixed more uniformly, and the pollutant emission is reduced.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
The invention designs a coaxial staged gas fuel combustion chamber head for a low-emission gas turbine, which consists of a fuel pipe, two stages of straight premixing sections, a stage of center class, fuel cavities of all stages, a reducing mixing section and an integrated venturi; the fuel and the air are premixed in the straight premixing section and then further mixed in the reducing mixing section, and a backflow area is formed under the action of the swirl vanes. The fuel is supplied by the duty fuel flow path and the first stage fuel flow path under the ignition working condition, the supply of the first stage fuel is gradually increased along with the rise of the working condition, the supply of the second stage fuel is opened, the supply of the duty fuel is gradually reduced until the duty fuel is closed, and the fuel supply of the first stage and the duty can stabilize the combustion flame and quickly ignite the second stage fuel. The tapered blending section and the integrated venturi can effectively avoid backfire. The burner is simple in structure, can realize stable combustion and has the characteristics of high combustion efficiency, low pollutant discharge and the like.
A coaxial staged gas fuel combustor head for a low emission gas turbine engine includes an on-duty stage fuel flow path 5, a first stage hub 14, a second stage hub 24, a first stage fuel conduit 61, a second stage fuel conduit 71;
the inner side space of the inner wall of the first-stage hub 14 consists of a first-stage straight premixing channel 1 and a first-stage tapered mixing channel 3, the front end of the first-stage tapered mixing channel 3 is communicated with the first-stage straight premixing channel 1, and the tail end of the first-stage tapered mixing channel 3 is provided with a first-stage venturi 31;
the inner side space of the inner wall of the second-stage hub 24 consists of a second-stage straight premixing channel 2 and a second-stage tapered mixing channel 4, the front end of the second-stage tapered mixing channel 4 is communicated with the second-stage straight premixing channel 2, and the tail end of the second-stage tapered mixing channel 4 is provided with a second-stage venturi 41;
the duty-stage fuel flow path comprises a duty-stage fuel conduit 51 and a central blunt body 52; the central blunt body 52 is arranged in the first-stage straight premixing channel 1, and a ring of first swirl blades 13 are arranged between the central blunt body 52 and the first-stage hub 14; a first-stage fuel cavity 62 is arranged between the inner wall and the outer wall of the first-stage hub 14, first-stage fuel jet holes 63 are uniformly distributed on the surface of the inner wall of the first-stage hub 14, and the first-stage fuel jet holes 63 are communicated with the first-stage fuel cavity 62;
the second-stage hub 24 is integrally positioned on the outer side of the outer wall of the first-stage hub 14, a circle of second swirl blades 23 are arranged between the first-stage hub 14 and the second-stage hub 24, the second swirl blades 23 are all positioned in the second-stage straight premixing channel 2, a swirl blade fuel cavity 73 is arranged inside the second swirl blades 23, a second-stage fuel jet hole 74 is formed in the surface of each second swirl blade 23, and the second-stage fuel jet hole 74 is communicated with the second-stage tapered mixing channel 4; a second-stage fuel cavity 72 is arranged between the inner wall and the outer wall of the second-stage hub 24;
the second stage fuel conduit 71 is integrally positioned outside the outer wall of the second stage hub 24, and the second stage fuel conduit 71 is communicated with the second stage fuel cavity 72 through a fuel conduit; the first stage fuel conduit 61 is arranged in front of the head end of the first stage hub 14, and the first stage fuel conduit 61 is communicated with the first stage fuel cavity 62 through a fuel branch; one end of the duty-level fuel conduit 51 is connected with the front end of the central blunt body 52, and the other end extends out of the bottom of the first-level fuel conduit 61; the central blunt body 52 is internally provided with an on-duty fuel cavity 53, an on-duty fuel jet hole 54 is formed along the slope surface and the end surface of the central blunt body 52, and the on-duty fuel jet hole 54 is communicated with the first-stage tapered mixing channel 3.
Wherein, the outlet end surface of the first-stage venturi 31 is flush with the throat part of the second-stage venturi 41.
The on-duty fuel jet holes 54 are formed along the slope surface and the end surface of the central blunt body 52, the aperture size is 1-2 mm, and the number of the blunt body slope surface jet holes and the end surface jet holes is the same as that of the first-stage blades.
The first-stage fuel jet holes 63 are uniformly distributed on the surface of the inner wall of the first-stage hub 14, and the aperture is 1-1.5 mm.
The second stage fuel jet holes 74 are formed in the surface of the second swirl vane 23, and the hole diameter is 0.8 mm-1.5 mm.
The first swirl vanes 13 and the second swirl vanes 23 are lossless straight vanes, the swirl angle of the vanes is 30-60 degrees, and the number of the vanes is 6-12.
The invention has the beneficial effects that:
the integrated venturi combined with the tapered mixing section at the tail end of the head of the combustion chamber can effectively lift the flame so as to avoid backfire, and purge air does not need to be arranged or class-wide diffusion fuel does not need to be opened under high working conditions; the center class and the first-stage fuel pipe form a partial sleeve form, so that disturbance to incoming flow air is reduced, and the air quantity distribution of flow passages among the blades is uniform; the second-stage fuel pipe is arranged outside the second-stage hub, so that the influence of the fuel pipe on the air intake of the second stage is reduced; the swirling air and the fuel are premixed in the straight premixing channel respectively and then enter the tapered mixing channel to be mixed, so that the fuel is mixed more uniformly, and the pollutant emission is reduced.
Example 1:
as shown in fig. 1-5, the present invention provides a coaxial staged gas fuel combustor head for a low emission gas turbine engine, comprising a first stage straight premix passage 1, a second stage straight premix passage 2, a first stage tapered blend passage 3, a second stage tapered blend passage 4, an on-duty stage fuel flow path 5, a first stage fuel flow path 6, and a second stage fuel flow path 7. The fuel flow of each stage can be independently controlled, so that the combustion temperature in the flame tube is controlled, and the pollution is reduced.
A first-stage fuel jet hole 63 and a first-stage air inlet 12 are formed in the first-stage straight premixing channel 1, one end of the first-stage tapered mixing channel 3 is communicated with the first-stage straight premixing channel 1, and a first-stage venturi 31 is arranged at the other end of the first-stage tapered mixing channel; a first-stage air flow path is formed by a first-stage air inlet 12, a first-stage straight premixing channel 1, a first-stage tapered mixing channel 3 and a first-stage venturi 31; the first stage straight section premix passage 1 is located between the center bluff body 52 and the first stage hub 14. A second-stage fuel jet hole 74 and a second-stage air inlet 22 are formed in the second-stage straight premixing channel 2, one end of the second-stage tapered mixing channel 4 is communicated with the second-stage straight premixing channel 2, and a second-stage venturi 41 is arranged at the other end of the second-stage tapered mixing channel; the end surface of the first-stage venturi 31 is flush with the throat part of the second-stage venturi 41; the second stage straight section premix passage 2 is located between the first stage hub 14 and the second stage hub 24; the second stage air inlet 22, the second stage straight premixing passage 2, the second stage tapered blending passage 4 and the second stage venturi 41 form a second stage air flow path. Wherein, the two-stage straight premixing channels 1 and 2 are provided with a first-stage swirl blade 13 and a second-stage swirl blade 23, the number of the first-stage swirl blade 13 and the number of the second-stage swirl blade 23 are 6 and 12 in sequence, and the thickness of the blades is 2mm and 3mm in sequence. The two stages all adopt lossless straight blades, the mounting angles of the swirl blades are both 40 degrees, and the two-stage premixing stage swirl numbers are respectively 0.6 and 0.7. The air forms rotational flow under the action of the rotational flow blades through the straight premixing channel, then the air is accelerated in the reducing mixing channel and is expanded through the venturi to form a backflow zone, and the venturi can effectively prevent tempering.
The class fuel conduit 51, the class fuel chamber 53 and the class fuel jet hole 54 constitute a class fuel flow path in the present example; the duty-level fuel guide pipe 51 is positioned in front of the central blunt body 52 and connected with the central blunt body 52, the duty-level fuel cavity 53 is positioned inside the central blunt body 52, the duty-level fuel jet hole is positioned at the tail end of the central blunt body 52, the circumferential hole diameter is 6, the end surface hole diameter is 1.5mm, and the arrangement mode can effectively form diffusion flame under the low working condition so as to enable the combustion to be stable.
The first stage fuel conduit 61, the first stage fuel cavity 62 and the first stage fuel jet orifice 63 constitute a first stage fuel flow path in this example; the fuel of the first-stage premixing stage enters a first-stage fuel cavity 62 from a fuel inlet through a fuel conduit 61 and is divided into four fuel conduit branches, and is ejected from a first-stage hub jet hole 63. The first-stage fuel guide pipe 61 is arranged in front of the first-stage hub 14 and coaxial with the duty-stage fuel guide pipe 51, the first-stage fuel cavity 62 is positioned in the first-stage hub 14, the first-stage hub jet holes 63 are uniformly distributed on the inner side of the first-stage hub 14, 5 holes are arranged in flow channels among blades, and the hole diameter is 1.5 mm. The first-stage hub jet hole 63 is arranged in a manner that fuel can be effectively prevented from gathering at the tail end of the central blunt body 52, so that a backfire phenomenon can be avoided.
In this example, the second stage fuel conduit 71, the second stage fuel cavity 72, the swirl vane fuel cavity 73, and the second stage fuel jet hole 74 form a second stage fuel flow path, the second stage fuel conduit 71 is located outside the second stage hub 24, the second stage fuel cavity 72 is located inside the second stage hub 24, the second stage swirl vane 23 fuel cavity is located inside the swirl vane, the second stage fuel jet hole is located on the swirler vane, the second stage fuel jet hole has a hole diameter of 1mm, 1.2mm, 1.5mm, so that the fuel can be mixed more uniformly to avoid local high temperature area in the combustion chamber.
The specific working process of the combustion chamber head fuel circuit is as follows:
the fuel is supplied by the duty fuel flow path and the first-stage fuel flow path under the ignition working condition, the supply of the first-stage fuel flow path is gradually increased along with the increase of the working condition, the second-stage fuel flow path is opened, the supply of the duty fuel flow path is gradually reduced until the duty fuel is closed, the fuel supply of the first stage and the duty can stabilize the combustion flame and quickly ignite the second-stage fuel, and therefore the generation of pollutants is reduced while the stable combustion is ensured.
The specific working process of the air circuit at the head part of the combustion chamber is as follows:
air is distributed from the two-stage air inlet to enter the two-stage straight premixing section and forms rotary flow under the action of the swirl vanes, then enters the tapered mixing channel for acceleration, and is expanded in the expansion section of the integrated venturi, so that a backflow zone can be formed in the flame tube while tempering is avoided.
As shown in FIG. 5, the present invention is applied to a model combustor, and when installed, a bolt hole 18 for fixing can be opened at the second stage tapered mixing passage 4 as shown in FIG. 2. The invention can be applied to an annular combustion chamber and a ring tube combustion chamber, and the size of the head of the rotary combustion chamber is adjusted according to the specific structure and the size of the gas turbine in practical application.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.