Gas turbine engine and mixer assembly for use therewith, combustion chamber, method of atomizing fuel

Abstract

The present application relates to a kind of gas turbine engine and the mixer assembly for it, combustion chamber, fuel atomization method.Therein, the mixer assembly for gas turbine engine includes: main combustion mixer, including: annular inner wall;Annular outer wall, at least part of the annular inner wall is formed annular chamber around;Multiple fuel injection holes, at least including first fuel injection hole and second fuel injection hole, the first fuel injection hole is located in the annular inner wall, the first fuel injection hole has first injection direction, the first injection direction is directed to the annular outer wall, the second fuel injection hole is located in the annular outer wall, the second fuel injection hole has second injection direction, the second injection direction is directed to the annular inner wall.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas turbine engines, and in particular to a gas turbine engine and a mixer assembly for use therein, a combustion chamber, a method of atomizing fuel. BACKGROUND

[0002] The increasing environmental awareness makes the reduction of pollutant emissions in the combustion process one of the main challenges in the development of aircraft engines. In order to achieve lower NOx emissions without increasing the concentration of carbon monoxide and unburned hydrocarbons in the exhaust gas, low-emission combustion forms such as lean premixed pre-vaporization and rich quenching lean combustion have been widely researched and applied in gas turbines and aircraft engines. However, as aircraft engines develop towards higher pressure ratios, the higher inlet pressure and temperature of the combustion chamber pose new challenges to efficient and low-pollution combustion organization methods.

[0003] The inventors of the present application have found that for high-pressure-ratio aircraft engines, due to the increase in temperature and pressure at the inlet, the auto-ignition time of the fuel is shortened, and the existing lean premixed combustion poses a risk of backfiring and auto-ignition. SUMMARY

[0004] It is an object of the present application to provide a mixer assembly for a gas turbine engine.

[0005] It is another object of the present application to provide a combustion chamber for a gas turbine engine.

[0006] It is still another object of the present application to provide a gas turbine engine.

[0007] It is still another object of the present application to provide a method of atomizing fuel for a gas turbine engine.

[0008] According to one aspect of the present application, a mixer assembly for a gas turbine engine comprises: a main fuel mixer comprising: an annular inner wall; an annular outer wall forming an annular chamber around at least part of the annular inner wall; a plurality of fuel injection holes comprising at least a first fuel injection hole and a second fuel injection hole, the first fuel injection hole being located at the annular inner wall, the first fuel injection hole having a first injection direction, the first injection direction being directed towards the annular outer wall, the second fuel injection hole being located at the annular outer wall, the second fuel injection hole having a second injection direction, the second injection direction being directed towards the annular inner wall.

[0009] The technical solution of the present application realizes the opposite jetting of the main combustion mixer fuel by the structure of the first jetting direction pointing to the annular outer wall and the second jetting direction pointing to the annular inner wall, so that the annular main combustion stage fuel collides with each other to be easily atomized and rapidly mixed with air, which not only retains the advantage of reducing the risk of self-ignition, backfire and combustion instability of direct injection relative to premixed combustion, but also has the advantage of uniform mixing of fuel and air. The principle lies in that the opposite jetting makes the fuel atomized by jetting, which ensures the uniformity of the rapid mixing of fuel and air, and the uniformity of fuel distribution also ensures the uniformity of the combustion temperature field, thereby improving the uniformity of the turbine inlet temperature distribution of the gas turbine engine.

[0010] Meanwhile, the structure of the annular chamber makes the main combustion stage flame be an overall annular flame, avoiding the disadvantage of uneven temperature distribution caused by flame coupling interference existing in the arrayed distribution of multiple independent main combustion stages.

[0011] In one or more embodiments of the mixer assembly, the axial position of the first fuel injection hole is the same as the axial position of the second fuel injection hole.

[0012] In one or more embodiments of the mixer assembly, the first jetting direction is opposite to the second jetting direction.

[0013] In one or more embodiments of the mixer assembly, at least one of the annular inner wall and the annular outer wall has a first contraction structure, and the flow area of the annular chamber decreases from upstream to downstream through the first contraction structure.

[0014] In one or more embodiments of the mixer assembly, the downstream of the contraction structure has an expansion structure, and the flow area of the annular chamber increases from upstream to downstream through the expansion structure.

[0015] In one or more embodiments of the mixer assembly, the expansion structure extends axially to the downstream end of the annular chamber, and the first contraction structure extends axially to the upstream end of the expansion structure.

[0016] In one or more embodiments of the mixer assembly, the axial position of the fuel injection hole is between the axial positions of the first contraction structure and the expansion structure.

[0017] In one or more embodiments of the mixer assembly, the axial position of the fuel injection hole is 20-30 mm away from the downstream outlet of the annular chamber.

[0018] In one or more embodiments of the mixer assembly, the mixer assembly further comprises a fuel pipeline, which is fluidly connected with the fuel injection hole.

[0019] In one or more embodiments of the mixer assembly, a first swirler is provided in the annular chamber, the first swirler being located at an upstream section of the annular chamber, and the fuel injection orifice being located at a downstream section of the annular chamber.

[0020] In one or more embodiments of the mixer assembly as claimed in any one of the preceding items, a pre-mix mixer is included, at least a portion of the pre-mix mixer being surrounded by the main mix mixer, the pre-mix mixer comprising an annular body having an outer surface constituting an annular inner wall of the main mix mixer.

[0021] In one or more embodiments of the mixer assembly, the annular body has an inner surface, the inner surface having a second converging structure, the second converging structure being located upstream of the first converging structure of the main mix mixer.

[0022] A combustor for a gas turbine engine according to another aspect of the present invention comprises: a combustion vessel; and a mixer assembly as described above disposed adjacent to the combustion vessel, a downstream end of the annular chamber of the mixer assembly being in direct communication with the combustion vessel, configured to provide a flow of a mixture of fuel and air to the combustion vessel.

[0023] A gas turbine engine according to yet another aspect of the present invention comprises a combustor as described above.

[0024] A method of atomizing fuel for a gas turbine engine according to yet another aspect of the present invention comprises: providing a main mixer, the main mixer being configured to inject fuel into the main mixer through a first fuel injection orifice located at an annular inner wall of the main mixer, and a second fuel injection orifice located at an annular outer wall of the main mixer, wherein the fuel is atomized by collision of a first fuel flow injected through the first fuel injection orifice and a second fuel flow injected through the second fuel injection orifice. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above mentioned and other features, properties and advantages of the present invention will become more apparent by reference to the following description of embodiments of the present invention taken in conjunction with the accompanying drawings, in which like reference numerals designate like features throughout the several views, and wherein:

[0026] Figure 1 Structure diagram of a combustor according to an embodiment;

[0027] Figure 2Fig. 1 is a schematic view of a part of a primary fuel mixer according to an embodiment;

[0028] Figure 3 Fig. 1 is a schematic view of a part of a primary fuel mixer according to an embodiment; Figure 1 Fig. 2 is a cross-sectional view of the structure of the combustion chamber according to the embodiment of Fig. 1.

[0029] Reference signs:

[0030] 1000 - Combustion chamber

[0031] 100 - Mixer assembly

[0032] 10 - Primary fuel mixer

[0033] 1 - Annular inner wall, 2 - Annular outer wall

[0034] 101 - Annular chamber, 1011 - Upstream section, 1012 - Downstream section, 1013 - Downstream end

[0035] 102 - First converging structure, 103 - Diverging structure, 1031 - Upstream end

[0036] 3 - Fuel injection hole, 31 - First fuel injection hole, 32 - Second fuel injection hole, D1 - First injection direction, D2 - Second injection direction

[0037] 4 - Fuel line, 41 - First fuel line, 42 - Second fuel line

[0038] 5 - Primary stage gas-liquid mixture

[0039] 51 - First swirler, 52 - Primary stage flame

[0040] 20 - Pre-mixing mixer, 201, 202 - Annular combustion passage

[0041] 21 - Annular body, 211 - Outer surface, 212 - Inner surface, 213 - Second converging structure, 214 - Second diverging structure

[0042] 22 - Centrifugal nozzle, 23 - Second swirler, 24 - Third swirler

[0043] 6 - Spray droplet

[0044] 13 - Pre-mixing stage flame

[0045] 200 - Combustion vessel

[0046] 16 - High-temperature gas Specific embodiments

[0047] Reference will now be made in detail to various embodiments of the application, examples of which are illustrated in the accompanying drawings and described below. While the application will be described in conjunction with the exemplary embodiments, it will be understood that the application is not limited to the exemplary embodiments. On the contrary, the application is intended to cover all alternatives, modifications, equivalents, and other embodiments that are included within the spirit and scope of the application as defined by the appended claims.

[0048] In the following description, the terms "axial", "radial", "circumferential", "inner", "outer", "upstream", "downstream" or other orientation terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or component referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application. In addition, "upstream" and "downstream" are distinguished based on the direction of airflow flow, specifically, the airflow flows from "upstream" to "downstream".

[0049] Meanwhile, specific words are used in the present application to describe the embodiments of the present application. As "one embodiment" and / or "an embodiment" means a certain feature, structure or characteristic in relation to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "an embodiment" or "one embodiment" mentioned in different positions in the specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be properly combined.

[0050] At present, with the development of aero-engines towards higher pressure ratio, higher inlet pressure and temperature of the combustion chamber puts higher requirements on efficient and low-pollution combustion organization mode.

[0051] The inventors of the present application have found through in-depth research that for high-pressure-ratio aero-engines, due to the increase of the inlet temperature and pressure, the self-ignition time of fuel is shortened, and the existing lean premixed combustion will bring the risk of backfire and self-ignition.

[0052] Lean direct injection technology directly injects fuel into the combustion chamber, and mixes with air for a very short time to form a flame. This combustion organization mode can reduce NOx pollutant emissions.

[0053] In a comparative scheme of the lean oil direct injection combustion chamber structure, the radial staged lean oil direct injection combustion chamber, the pre-combustion stage flame is generally still in the diffusion combustion mode, and the main combustion stage is in the lean oil direct injection combustion mode formed by multiple swirler, and the main combustion stage is in the array distribution, that is, multiple independent main combustion stages are arranged in the circumference. The inventor finds that although this comparative scheme solves the fuel adjustment problem of the lean oil direct injection combustion chamber, the flames formed by the independent main combustion stages are coupled and interfered with each other, a local high temperature zone is easily formed downstream of the combustion chamber, the temperature distribution is not uniform enough, it is difficult to further reduce the pollutant emission and improve the uniformity of the turbine inlet temperature distribution, and the local high temperature zone also causes the risk of backfire and spontaneous combustion due to local flow instability.

[0054] Based on the above considerations, the inventor has designed a mixer assembly for a gas turbine engine through in-depth research. The structure of the first injection direction pointing to the annular outer wall and the second injection direction pointing to the annular inner wall realizes the opposite injection of the main combustion mixer fuel, so that the annular main combustion stage fuel collides with each other to be easily atomized and rapidly mixed with air. This not only retains the advantage of reducing the risk of backfire, spontaneous combustion and combustion instability of direct injection relative to premixed combustion, but also has the advantage of uniform mixing of fuel and air. The principle lies in that the opposite injection causes the fuel to be atomized and sprayed, ensuring the uniformity of the rapid mixing of fuel and air, and the uniformity of fuel distribution also ensures the uniformity of the combustion temperature field, thereby improving the uniformity of the turbine inlet temperature distribution of the gas turbine engine.

[0055] Moreover, the structure of the annular chamber makes the main combustion stage flame an overall annular flame, avoiding the disadvantage of the temperature distribution being not uniform due to the flame coupling interference of the array distributed multiple independent main combustion stages in the comparative scheme, and avoiding the risk of backfire and spontaneous combustion due to local flow instability caused by the local high temperature zone.

[0056] Although the mixer assembly disclosed in the embodiments of the present application is applicable to a gas turbine engine, taking an aero-engine as an example, but not limited thereto, for example, it can also be a marine gas turbine, a ground gas turbine, etc.

[0057] In the following introduction, "fuel" takes aviation fuel, that is, aviation kerosene, as an example, but not limited thereto, as long as the fuel needs to be atomized, the mixer assembly introduced in the embodiments can be applicable.

[0058] Reference Figure 1 Combination Figure 3As shown, in one embodiment, the specific structure of the mixer assembly 100 for a gas turbine engine can be, including a main combustion mixer 10. The main combustion mixer 10 includes an annular inner wall 1, an annular outer wall 2, and a plurality of fuel injection holes 3. The annular outer wall 2 forms an annular chamber 101 around at least part of the annular inner wall 1. The plurality of fuel injection holes 3 includes at least a first fuel injection hole 31 and a second fuel injection hole 32, the first fuel injection hole 31 is located on the annular inner wall 1, the first fuel injection hole 31 has a first injection direction D1, the first injection direction D1 points to the annular outer wall 2, the second fuel injection hole 32 is located on the annular outer wall 2, the second fuel injection hole 32 has a second injection direction D2, the second injection direction D2 points to the annular inner wall 1.

[0059] The meaning of "the first injection direction D1 points to the annular outer wall 2" and "the second injection direction D2 points to the annular inner wall 1" is not limited to vertical pointing, as long as the injection direction is towards the annular wall, the angle between the injection direction and the annular wall is not particularly specified. Because of the direct injection combustion chamber technology, for example Figure 2 As shown, the first injection direction D1 and the second injection direction D2 respectively point to the annular outer wall 2 and the annular inner wall 1, and are both generally directed towards the downstream (combustion container 200).

[0060] The meaning of "the plurality of fuel injection holes 3 includes at least a first fuel injection hole 31 and a second fuel injection hole 32" is that the first fuel injection hole 31 and the second fuel injection hole 32 form a group, and the plurality of fuel injection holes 3 can include multiple groups of "first fuel injection holes 31 and second fuel injection holes 32", which are uniformly arranged on the circumferential direction of the annular inner wall 1 and the annular outer wall 2, to form a circumferentially uniform main combustion stage direct injection flame. The number of groups is usually 12-36, for example Figure 3 As shown, 12 groups of first fuel injection holes 31 and second fuel injection holes 32 are uniformly arranged on the circumferential direction of the annular inner wall 1 and the annular outer wall 2.

[0061] The beneficial effect of such an arrangement is that, through the structure of the first injection direction pointing to the annular outer wall and the second injection direction pointing to the annular inner wall, the main combustion mixer fuel is realized by the structure of the first injection direction pointing to the annular outer wall and the second injection direction pointing to the annular inner wall. The main combustion stage fuel collides with each other and is easy to atomize and quickly mix with air, which not only retains the advantage of direct injection reducing the risk of spontaneous combustion, backfire and combustion instability compared with premixed combustion, but also has the advantage of uniform mixing of fuel and air. The principle is that the fuel is atomized by the opposite injection, the particle size of the atomized fuel is small, the component distribution is uniform, which ensures the uniformity of the fuel and air quickly mixed, and the uniformity of the fuel distribution also ensures the uniformity of the combustion temperature field, thereby improving the uniformity of the turbine inlet temperature distribution of the gas turbine engine.

[0062] And, the structure of the annular chamber makes the main combustion stage flame an overall annular flame, avoiding the disadvantage of uneven temperature distribution caused by the flame coupling interference existing in the arrayed multiple independent main combustion stages in the comparative scheme, and avoiding the risk of backfire and spontaneous combustion caused by local high temperature area and local flow instability.

[0063] Reference is made to Figure 1 As shown in some embodiments, the specific structure of the fuel injection hole 3 can be that the axial position of the first fuel injection hole 31 is the same as that of the second fuel injection hole 32.

[0064] Here, the "axial position being the same" means that the first fuel injection hole 31 and the second fuel injection hole 32 are oppositely arranged in the radial direction, for example Figure 1 As shown, the first fuel injection hole 31 is oppositely arranged in the radial direction with the second fuel injection hole 32.

[0065] The beneficial effect of such an arrangement is that the structure is simple and compact, facilitating the formation of two oppositely directed spray jets.

[0066] Reference is made to Figure 2 In combination Figure 3 As shown in some embodiments, the specific structure of the fuel injection hole 3 can be that the first injection direction D1 is opposite to the second injection direction D2.

[0067] Here, "opposite" means that the first injection direction D1 and the second injection direction D2 can overlap in the radial direction, so that the spray jets sprayed by the first fuel injection hole 31 and the second fuel injection hole 32 can collide with each other and quickly atomize and evaporate.

[0068] The beneficial effect of such an arrangement is that the first injection direction D1 and the second injection direction D2 are opposite, which can effectively form a counter-attack spray jet, i.e. the spray jets sprayed by the first fuel injection hole 31 and the second fuel injection hole 32 can collide with each other and quickly atomize and evaporate, avoiding flame coupling interference, making the turbine inlet temperature distribution uniform, and further improving the combustion stability.

[0069] Reference is made to Figure 1 In combination Figure 2 As shown in some embodiments, the specific structure of the mixer assembly 100 can be that at least one of the annular inner wall 1 and the annular outer wall 2 has a first contraction structure 102, and the flow area of the annular chamber 101 decreases from upstream to downstream through the first contraction structure 102.

[0070] The beneficial effect of such an arrangement is that the airflow passing through the first contraction structure will accelerate, making the fuel and air mix more quickly, which can effectively prevent backfire and improve the stability of combustion.

[0071] Reference is made to Figure 1 In combination Figure 2As shown, in some embodiments, the mixer assembly 100 can have a specific structure that the downstream of the first converging structure 102 has a diverging structure 103, and the flow area of the annular chamber 101 increases from the upstream to the downstream through the diverging structure 103.

[0072] The "flow area of the annular chamber 101", specifically, decreases through the first converging structure 102 from the upstream to the downstream, and then increases through the diverging structure 103. Figure 2 As shown, the fuel injection hole 3 is located at the joint of the first converging structure 102 and the diverging structure 103, and the flow area of the annular chamber 101 is the smallest at the position of the fuel injection hole 3.

[0073] The beneficial effect of such an arrangement is that after the airflow is accelerated through the first converging structure, the fuel injection hole 3 is located at the position where the flow area of the annular chamber 101 is the smallest, i.e., the airflow has the maximum flow rate at this position, and the fuel can be quickly mixed with the air, thereby preventing self-ignition, backfire, and improving combustion stability. Then, the airflow has a certain expansion angle through the diverging structure, which can make the distribution of the air-fuel spray mixture more reasonable, the mixture is fully and uniformly burned, the pollutant emission is reduced, and the uniformity of the combustion temperature field is further improved, thereby improving the uniformity of the turbine inlet temperature distribution of the gas turbine engine.

[0074] Continuing to refer to Figure 1 In combination Figure 2 As shown, in some embodiments, the mixer assembly 100 can have a specific structure that the diverging structure 103 extends axially to the downstream end 1013 of the annular chamber 101, and the first converging structure 102 extends axially to the upstream end 1031 of the diverging structure 103. The beneficial effect of such an arrangement is that the airflow accelerated through the first converging structure 102 is decelerated in time through the diverging structure 103 to ensure sufficient combustion.

[0075] Referring to Figure 2 As shown, in some embodiments, the mixer assembly 100 can have a specific structure that the axial position of the fuel injection hole 3 is located between the axial positions of the first converging structure 102 and the diverging structure 103.

[0076] The "axial position of the fuel injection hole 3", specifically, for example Figure 2 As shown, the fuel injection hole 3 is located at the joint of the first converging structure 102 and the diverging structure 103, i.e., at the position where the flow area of the annular chamber 101 is the smallest.

[0077] The beneficial effect of such arrangement is that the air flow is accelerated through the first contraction structure 102 to mix with the spray from the fuel injection hole 3 to prevent backfire, and then decelerated through the expansion structure 103 to make the combustion more complete. The fuel injection hole 3 is located axially between the first contraction structure 102 and the expansion structure 103, which can make the effect of preventing backfire better and the combustion more complete and effective to reduce pollution emissions.

[0078] With continued reference to Figure 2 As shown, in some embodiments, the specific structure of the mixer assembly 100 can be that the axial position of the fuel injection hole 3 is 20-30 mm away from the downstream outlet of the annular chamber 101 in the axial direction. The beneficial effect of such arrangement is that it can effectively prevent self-ignition and backfire in the annular chamber and improve combustion stability. The principle is that the spray jets from the first fuel injection hole 31 and the second fuel injection hole 32 can collide with each other, quickly atomize and evaporate, and the fuel does not need to mix with air for a long distance and a long time before reaching the downstream outlet, so the fuel injection hole 3 can be arranged close to the downstream outlet to prevent self-ignition and backfire in the annular chamber and improve combustion stability.

[0079] With reference to Figure 1 As shown, in some embodiments, the specific structure of the mixer assembly 100 can also include a fuel pipe 4, which is fluidly connected to the fuel injection hole 3. Here, "fluidly connected" means that the fuel is delivered to the fuel injection hole 3 through the fuel pipe 4 and sprayed out through the fuel injection hole 3. Such arrangement is simple and easy to manufacture.

[0080] With reference to Figure 1 In combination Figure 2 As shown, in some embodiments, the specific structure of the annular chamber 101 can be that the annular chamber 101 is provided with a first swirler 51, and the axial position of the first swirler 51 is located in the upstream section 1011 of the annular chamber 101, and the axial position of the fuel injection hole 3 is located in the downstream section 1012 of the annular chamber 101. The first swirler 51 is arranged one-to-one with the fuel injection hole 3. The flow process of the air flowing through the first swirler 51, for example Figure 1 、 Figure 2 As shown, the air a passing through the first swirler 51, passing through the first contraction structure 102, at the fuel injection hole 3, and the liquid mist of the counter-attack spray jet sprayed in the first injection direction D1 and the second injection direction D2 quickly mixes and evaporates, forming a gas-liquid mixture 5 in the expansion structure 103 to enter the combustion chamber 200 to realize the direct injection of the main combustion stage flame 52.

[0081] In some embodiments, as Figure 2As shown, the first injection direction D1 and the second injection direction D2 of the opposing spray jet are respectively supplied with fuel by the first fuel pipe 41 and the second fuel pipe 42, and the first injection direction D1 and the second injection direction D2 of the opposing spray jet form the gas-liquid mixture 5 with a certain rotational direction and opening angle under the action of the air a passing through the first swirler 51.

[0082] Reference Figure 1 In combination Figure 3 As shown, in some embodiments, the specific structure of the mixer assembly 100 can also be that it includes a pre-combustion mixer 20. At least part of the pre-combustion mixer 20 is surrounded by the main combustion mixer 10, and the pre-combustion mixer 20 includes an annular body 21 having an outer surface 211 constituting the annular inner wall 1 of the main combustion mixer 10.

[0083] The "at least part of the pre-combustion mixer 20 is surrounded by the main combustion mixer 10" specifically means that part of the pre-combustion mixer 20 is located radially inside the main combustion mixer 10.

[0084] The beneficial effect of such an arrangement is that a radial staged combustion mode is formed, which can flexibly adjust the fuel according to different working conditions, and at the same time cooperate with lean direct injection combustion to achieve high-efficiency, stable and low-pollution combustion.

[0085] In some embodiments, as shown, Figure 3 As shown, the main combustion mixer 10 and the pre-combustion mixer 20 are concentrically distributed, the main combustion mixer 10 surrounds the pre-combustion mixer 20, and the overall structure is uniform and compact.

[0086] Reference Figure 1 In combination Figure 2 As shown, in some embodiments, the specific structure of the annular body 21 can be that the annular body 21 has an inner surface 212, and the inner surface 212 has a second contraction structure 213, and the axial position of the second contraction structure 213 is located upstream of the first contraction structure 102 of the main combustion mixer 10.

[0087] In some embodiments, as shown, Figure 1 As shown, the pre-combustion mixer 20 includes a centrifugal nozzle 22, a second swirler 23, and a third swirler 24, the second swirler 23, the third swirler 24, and the centrifugal nozzle 22 are arranged in the radial direction from outside to inside on the radial inside of the annular body 21, the centrifugal nozzle 22 is located at the center of the annular body 21, the third swirler 24 is located radially outside the centrifugal nozzle 22, the third swirler 24 is located radially inside the second swirler 23, and the second swirler 23 and the third swirler 24 are arranged staggered in the axial position, and the second swirler 23 is located on the downstream side of the third swirler 24.

[0088] The flow process of the air flowing through the second swirler 23 and the third swirler 24, for example Figure 1 As shown, the air passes through the second swirler 23 and the third swirler 24 into the two annular combustion channels 201, 202 of the pre-combustion mixer 20 respectively. The air b passing through the third swirler 24 is mixed with the spray droplets 6 from the centrifugal nozzle 22 sufficiently. The pre-combustion stage gas-liquid mixture is further mixed with the air c passing through the second swirler 23 to achieve the effect of sufficient atomization and evaporation. The pre-combustion stage gas-liquid mixture mixed with the air c passes through the second contraction structure 213 and then enters the second expansion structure 214, and then enters the combustion container 200 to form the diffusion combustion pre-combustion stage flame 13. The second expansion structure 214 extends axially to the downstream end of the annular body 21, and the second contraction structure 213 extends axially to the upstream end of the second expansion structure 214. The purpose of arranging the second expansion structure 214 is to have a certain expansion angle, so that the pre-combustion stage flame can be fully expanded and fully contacted with the main combustion stage flame, so that the combustion is more sufficient, the uniformity of the combustion is improved, and the pollution emission is reduced.

[0089] The axial position of the second contraction structure 213 is upstream of the first contraction structure 102 of the main combustion mixer 10, specifically, the first contraction structure 102 is closer to the combustion container 200 (the combustion container 200 may, for example, be a flame tube of a combustion chamber of a gas turbine engine as shown in the figure), and the second contraction structure 213 is farther away from the combustion container 200. The principle of such an arrangement is that at a lower engine thrust, the spray droplets 6 exiting the centrifugal nozzle 22 can need to travel a longer distance to be fully atomized and evaporated, which can promote more sufficient combustion. At a large engine thrust, the main combustion stage gas-liquid mixture 5 formed by the main combustion mixer 10 needs to be able to be quickly atomized and evaporated into the combustion container 200 under the action of the high-temperature and high-pressure air a, and, as Figure 1 As shown, the pre-combustion stage flame 13 can be fully expanded first, so that the mixture of air and fuel at the outlet of the main combustion stage can be ignited more uniformly and sufficiently, so that the combustion uniformity is good, thereby improving the turbine inlet temperature distribution uniformity of the gas turbine engine, which is also beneficial to stable combustion at a large thrust. Therefore, the first contraction structure 102 is closer to the combustion container 200 in the axial position than the second contraction structure 213.

[0090] In some embodiments, as shown in Figure 1 The air a passing through the first swirler 51, the air c passing through the second swirler 23, and the air b passing through the third swirler 24 have the same rotational direction, so that the fuel injected from the fuel injection hole 3 can be mixed with the air uniformly, so that the combustion is more efficient and sufficient, and the pollution emission is further reduced.

[0091] With continued reference to Figure 1As shown, in one embodiment, the specific structure of the combustion chamber 1000 for a gas turbine engine can be, including a combustion vessel 200 and a mixer assembly 100 as described above. The mixer assembly 100 is arranged adjacent to the combustion vessel 200, the downstream end of the annular chamber 101 of the mixer assembly 100 directly communicates with the combustion vessel 200, configured to provide a flow of fuel and air mixture to the combustion vessel 200. With the combustion chamber 1000 including the mixer assembly 100 as described above, both radial staging combustion and flexible fuel adjustment for different operating conditions are ensured, and the annular direct injection technology of the main combustion mixer is utilized to form flexible, efficient and stable low pollution combustion, while improving the uniformity of turbine inlet temperature distribution.

[0092] In some embodiments, as shown in Figure 1 , Figure 2 Under different operating conditions, the proportion of fuel provided by the centrifugal nozzle 22 and the first and second fuel lines 41 and 42 is adjusted to flexibly control the combustion organization mode of the combustion chamber, forming low pollution combustion. At the same time, the high-temperature gas 16 after combustion has a relatively uniform temperature distribution, improving the uniformity of turbine inlet temperature distribution.

[0093] In one embodiment, the specific structure of the gas turbine engine can be, including the combustion chamber 1000 as described above. With the gas turbine engine including the combustion chamber 1000 as described above, flexible adjustment of the fuel and air ratio of the combustion chamber under different operating conditions can be achieved, stable, efficient and low-emission combustion can be achieved, and the uniformity of turbine inlet temperature distribution can be improved.

[0094] Under different operating conditions, the combustion organization mode of the combustion chamber 1000 is flexibly adjusted by different fuel distribution of the pre-combustion stage flame 13 and the directly injected main combustion stage flame 52, to reduce pollutant emissions, which is specifically divided into the following cases: (1) generally, when the gas turbine engine is less than 30% thrust condition, only the pre-combustion mixer 20 works; (2) when the gas turbine engine is 50% thrust condition, the pre-combustion mixer 20 and the main combustion mixer 10 work simultaneously, at this time the fuel distribution ratio of the pre-combustion mixer 20 and the main combustion mixer 10 is close; (3) when the gas turbine engine is greater than 70% thrust condition, the pre-combustion mixer 20 and the main combustion mixer 10 work simultaneously, at this time the fuel distributed to the main combustion mixer 10 is greater than that of the pre-combustion mixer 20.

[0095] When in high-thrust condition (generally refers to the main combustion stage injection fuel accounts for more than 90% of the injection fuel), the high-temperature and high-pressure air is rapidly mixed with the fine droplets formed by the counterflow jet atomization of the fuel injection hole 3 in the annular chamber 101 of the main combustion mixer 10, forming lean direct combustion, which can effectively prevent backfire, spontaneous combustion and improve combustion stability.

[0096] In one embodiment, a specific step of a method for atomizing fuel for a gas turbine engine can be, comprising providing a primary mixer. The primary mixer is configured to inject fuel into the primary mixer through first fuel injection holes located on an annular inner wall of the primary mixer and second fuel injection holes located on an annular outer wall of the primary mixer, wherein the fuel is atomized by the collision of a first fuel flow injected through the first fuel injection holes and a second fuel flow injected through the second fuel injection holes.

[0097] The method for atomizing fuel for a gas turbine engine can effectively improve combustion efficiency and reduce pollutant emissions.

[0098] In summary, the beneficial effects of the gas turbine engine, the mixer assembly, the combustion chamber, and the method for atomizing fuel for the gas turbine engine as described in the above embodiments include one or a combination of the following:

[0099] 1. By the structure of the first injection direction pointing to the annular outer wall and the second injection direction pointing to the annular inner wall, the counter- injection of the primary fuel mixer is realized, which makes the annular primary fuel collide with each other and is easy to atomize and quickly mix with air. This not only retains the advantage of reducing the risk of self-ignition, backfire, and combustion instability of direct injection relative to premixed combustion, but also has the advantage of uniform mixing of fuel and air. The principle is that the counter-injection makes the fuel spray atomize each other, ensuring the uniformity of the rapid mixing of fuel and air, and the uniformity of fuel distribution also ensures the uniformity of the combustion temperature field, thereby improving the uniformity of the turbine inlet temperature distribution of the gas turbine engine.

[0100] Moreover, the structure of the annular chamber makes the primary flame a whole annular flame, avoiding the disadvantage of temperature distribution unevenness caused by flame coupling interference of multiple independent primary stages in the array distribution in the comparative scheme, and avoiding the risk of local high-temperature area also causing local flow instability and backfire, self-ignition.

[0101] 2. The combustion chamber 1000 comprising the mixer assembly 100 as described above is adopted, which not only ensures radial staged combustion and flexible fuel adjustment for different operating conditions, but also utilizes the annular direct injection technology of the primary mixer to form flexible, efficient, and stable low-pollution combustion while improving the uniformity of the turbine inlet temperature distribution.

[0102] 3. The gas turbine engine comprising the combustion chamber 1000 as described above can realize flexible fuel adjustment under different operating conditions, achieve stable, efficient, and low-emission combustion, and improve the uniformity of the turbine inlet temperature distribution.

[0103] 4. The method for atomizing fuel for a gas turbine engine as described above can effectively improve combustion efficiency and reduce pollutant emissions.

[0104] Although the present application is disclosed with reference to the preferred embodiments above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solutions of the present application, all fall within the protection scope defined by the claims of the present application.

Claims

1. A mixer assembly (100) for a gas turbine engine characterized by, Comprising: a main combustion mixer (10) comprising: an annular inner wall (1); an annular outer wall (2) forming an annular chamber (101) around at least part of the annular inner wall (1); a plurality of fuel injection holes (3) including at least a first fuel injection hole (31) located at the annular inner wall (1), the first fuel injection hole (31) having a first injection direction (D1) pointing towards the annular outer wall (2), and a second fuel injection hole (32) located at the annular outer wall (2), the second fuel injection hole (32) having a second injection direction (D2) pointing towards the annular inner wall (1); the axial position of the first fuel injection hole (31) is the same as that of the second fuel injection hole (32); the first injection direction (D1) is opposite to the second injection direction (D2).

2. The mixer assembly (100) of claim 1, wherein, At least one of the annular inner wall (1) and the annular outer wall (2) has a first contraction structure (102), the flow area of the annular chamber (101) decreases from upstream to downstream through the first contraction structure (102).

3. The mixer assembly (100) of claim 2, wherein, Downstream of the contraction structure (102) is an expansion structure (103), the flow area of the annular chamber (101) increases from upstream to downstream through the expansion structure (103).

4. The mixer assembly (100) of claim 3, wherein, The expansion structure (103) extends axially to the downstream end of the annular chamber (101), and the first contraction structure (102) extends axially to the upstream end of the expansion structure (103).

5. The mixer assembly (100) of claim 3, wherein, The axial position of the fuel injection hole (3) is between the axial positions of the first contraction structure (102) and the expansion structure (103).

6. The mixer assembly (100) of claim 1, wherein, The axial distance between the axial position of the fuel injection hole (3) and the downstream outlet of the annular chamber (101) is 20-30mm.

7. The mixer assembly (100) of claim 1, wherein, The mixer assembly (100) further comprises a fuel pipeline (4) fluidly connected with the fuel injection hole (3).

8. The mixer assembly (100) of claim 1, wherein, A first swirler (51) is arranged in the annular chamber (101), the axial position of the first swirler (51) is located in the upstream section (1011) of the annular chamber (101), and the axial position of the fuel injection hole (3) is located in the downstream section (1012) of the annular chamber (101).

9. The mixer assembly (100) according to any one of claims 1 to 8, characterized in that Comprising a pre-combustion mixer (20) at least partially surrounded by the main combustion mixer (10), the pre-combustion mixer (20) comprising an annular body (21) having an outer surface (211) constituting the annular inner wall (1) of the main combustion mixer (10).

10. The mixer assembly (100) of claim 9, wherein, The annular body (21) has an inner surface (212) having a second contraction structure (213), the axial position of the second contraction structure (213) is upstream of the first contraction structure (102) of the main combustion mixer (10).

11. A combustor (1000) for a gas turbine engine characterized by, Comprising: a combustion vessel (200); and ​ A mixer assembly (100) as claimed in any one of claims 1 to 10 is provided adjacent to the combustion vessel (200), a downstream end of the annular chamber (101) of the mixer assembly (100) directly communicating with the combustion vessel (200) and configured to provide a flow of the mixture of fuel and air to the combustion vessel (200).

12. A gas turbine engine characterized by, A combustion chamber (1000) as claimed in claim 11 is included.

13. A method for atomizing fuel for a gas turbine engine characterized by, A combustion chamber (1000) as claimed in claim 11 is included. A mixer assembly as claimed in claim 1 is provided, the primary fuel mixer being arranged to: Fuel is injected into the primary fuel mixer through first fuel injection orifices located in an inner annular wall of the primary fuel mixer and second fuel injection orifices located in an outer annular wall of the primary fuel mixer, wherein the fuel is atomized by impingement of a first fuel stream injected through the first fuel injection orifices and a second fuel stream injected through the second fuel injection orifices.

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