Coaxial staged combustion chamber head based on cannula fuel supply and method of supply

Abstract

The application provides a coaxial staged combustion chamber head based on a sleeve fuel supply and a supply method, and belongs to the field of combustion chambers, and aims at solving the problem of large fuel pipeline space occupation rate of existing combustion chambers. The head comprises a fuel supply sleeve, a bluff body component, an N-stage wheel hub and N-stage rotating flow vanes; the fuel supply sleeve comprises a plurality of stages of fuel sleeves coaxially nested, is provided with the bluff body component at the tail end, and the fuel cavity in the bluff body component is in communication with the central conduit of the plurality of stages of fuel sleeves; the bluff body component is coaxially nested with the N-stage wheel hub outside; the tail end of the bluff body component and the tail end of each stage of wheel hubs of the N-stage wheel hub are located at different positions on the same axis; the N-stage rotating flow vanes comprise first-stage rotating flow vanes to N-stage rotating flow vanes; N-i+1 fuel cavities are formed in the i-stage rotating flow vanes, and the i-stage rotating flow vanes are provided with i-stage fuel injection holes. The above-mentioned technology of the application can be applied to general combustion chamber or gas turbine combustion chamber technology, and the space utilization rate is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas turbine combustion chamber, in particular to a coaxial staged combustion chamber head based on sleeve type fuel supply and a supply method. BACKGROUND

[0002] Modern low-pollution gas turbines widely adopt lean premixed combustion technology to control nitrogen oxide emissions. This technology mainly reduces the equivalence ratio and combustion temperature by increasing the air intake amount of the head and strengthening the mixing uniformity of fuel and air, thereby reducing the generation rate of thermal nitrogen oxides. How to achieve short-distance rapid transport and mixing in the limited space of the combustion chamber, and how to achieve an efficient and low-space-occupancy fuel supply scheme for the combustion chamber head are all research focuses of low-emission combustion chambers.

[0003] In recent years, there have also been many patent applications for coaxial staged combustion chambers in China. Patent application No. 201910312864.X discloses a coaxial staged swirl and mixing integrated head for a gas fuel combustion chamber. The main part is a three-stage mixing / swirl integrated tower-type swirler. The first and second stage swirlers do not use a double-channel supply mode for fuel supply, and the space occupancy of the fuel pipe is relatively large. Patent application No. 202110664719.5 discloses a coaxial staged gas fuel combustion chamber head for a low-emission gas turbine. The two-stage premixing stages are flat sections, the center value class and the first stage fuel pipe are in a partial sleeve form, and the second stage fuel pipe is separately connected from the second stage hub. The space occupancy of the fuel pipe is relatively large and the head air intake amount is not large. SUMMARY

[0004] In view of the above problems, the present application proposes a coaxial staged combustion chamber head based on sleeve type fuel supply and a supply method to solve the problem of large fuel pipe space occupancy in the prior art.

[0005] According to an aspect of the present application, there is provided a coaxial staged combustion chamber head based on a cannula fuel supply, comprising a fuel supply cannula, a bluff body component, an N-stage wheel hub and an N-stage swirler vane; wherein N is an integer greater than or equal to 1; the fuel supply cannula comprises a multi-stage fuel cannula coaxially nested, the central conduit of the multi-stage fuel cannula is a value class fuel pipe; the N-stage conduit is nested outside the central conduit, the stage number of the N-stage conduit increases from the outermost layer to the inside; the multi-stage fuel cannula is provided with the bluff body component at the end, the fuel cavity in the bluff body component is in communication with the central conduit of the multi-stage fuel cannula; the N-stage wheel hub is coaxially nested outside the bluff body component, the stage number of each stage of the N-stage wheel hub increases from the inside to the outside; the end of the bluff body component and the end of each stage of the N-stage wheel hub are located at different positions on the same axial line; from the end of the central conduit to the end of the fuel supply cannula in the direction away from the fuel supply cannula, the end of the bluff body component, the end of each stage of the N-stage wheel hub with increasing stage number are sequentially arranged; the N-stage swirler vane comprises a first-stage swirler vane to an N-stage swirler vane; the first-stage swirler vane is arranged between the bluff body component and the first-stage wheel hub; the swirler vane corresponding to the higher stage number is arranged between two adjacent stages of the wheel hub; N-i+1 fuel cavities are opened in the i-stage swirler vane, and an i-stage fuel injection hole is arranged on the i-stage swirler vane; one of the N-i+1 fuel cavities is used for communication with the i-stage fuel injection hole, and the remaining N-i fuel cavities are respectively used for communication with the fuel cavities of the downstream swirler vane; wherein i=1, 2, …, N.

[0006] Further, N=2; the fuel supply sleeve is a three-layer fuel duct, including a duty class fuel duct, a first class fuel duct and a second class fuel duct; the bluff body component is a center bluff body; the N class wheel hub includes a first class wheel hub and a second class wheel hub; the N class rotational flow vane includes a first class rotational flow vane and a second class rotational flow vane; the duty class fuel duct, the second class fuel duct and the first class fuel duct are coaxially nested from inside to outside in sequence; the center bluff body is located at the end of the three-layer fuel duct, a fuel cavity in the center bluff body is communicated with the duty class fuel duct, and the center bluff body is provided with an axial fuel injection hole and a radial fuel injection hole; the center bluff body, the first class wheel hub and the second class wheel hub are coaxially nested from inside to outside in sequence, and along the center axis direction, they are sequentially arranged from left to right as follows: the end of the center bluff body, the end of the first class wheel hub and the end of the second class wheel hub; the first class wheel hub is provided with a first class wheel hub fuel cavity; the first class rotational flow vane is located between the center bluff body and the first class wheel hub, two fuel cavities are formed in the first class rotational flow vane, which are an upstream fuel cavity and a downstream fuel cavity; the windward side and the leeward side of the first class rotational flow vane are provided with a first class fuel injection hole, and the first class fuel injection hole is communicated with the upstream fuel cavity; the second class rotational flow vane is located between the first class wheel hub and the second class wheel hub, adopts a NACA-9612 blade type, a fuel cavity is formed in the blade, and the windward side and the leeward side of the blade are provided with a second class fuel injection hole, and the fuel injection hole is communicated with the fuel cavity.

[0007] Further, the end of the first class fuel duct is a tapered section, and the tapered section extends to the upstream fuel cavity in the first class rotational flow vane; the second class fuel duct extends to the downstream fuel cavity in the first class rotational flow vane.

[0008] Further, the fuel supply sleeve is bent by 0-90° after being led out of the rotational flow device and is connected with an outer fuel pipeline of the combustion chamber; the end surface of the center bluff body is provided with a plurality of axial fuel injection holes, and a plurality of radial fuel injection holes are uniformly arranged at a predetermined distance from the end surface in the circumferential direction.

[0009] Further, the length of the first class wheel hub fuel cavity accounts for 75%-85% of the total length of the wheel hub, and the minimum wall thickness is greater than 1 mm to ensure the structural strength; the included angle between the tapered section of the first class wheel hub and the center axis is β, and the included angle between the tapered section of the second class wheel hub and the center axis is γ, and the values of β and γ are in the range of 30°-60°.

[0010] Further, the first stage of the rotating flow vane number is 6-8, the second stage of the rotating flow vane number is 12-16, each vane windward side and leeward side is arranged with 3 fuel injection holes, the hole diameter is 0.6-1mm; the shape of the upstream fuel cavity and the downstream fuel cavity in the first stage of the rotating flow vane is consistent with the shape of the first stage of the rotating flow vane after combination, the shape of the second stage of the rotating flow vane fuel cavity in the second stage of the rotating flow vane is consistent with the shape of the second stage of the rotating flow vane; the upstream fuel cavity is communicated with the first stage of the fuel guide pipe, the downstream fuel cavity is communicated with the second stage of the fuel guide pipe, the first stage of the fuel hub cavity and the second stage of the rotating flow vane fuel cavity, and the minimum wall thickness is greater than 1mm.

[0011] According to another aspect of the present application, a fuel supply method using the coaxial staged combustion chamber head based on the sleeve type fuel supply is also provided, the method comprising: all fuel entering the head through the fuel guide pipe inlet, and main flow air entering the flow channel where the rotating flow vane is located through the air inlet; the duty stage fuel / air being sprayed through the duty stage fuel guide pipe from the oblique radial fuel injection hole and the axial fuel injection hole on the center blunt body, and the transported working medium being fuel when the duty stage works and being air otherwise to prevent the center blunt body from being ablated; the first stage fuel flowing into the upstream fuel cavity in the first stage of the rotating flow vane through the first stage of the fuel guide pipe, and being sprayed from the first stage of the fuel injection hole and being fully premixed with air downstream of the vane; and the second stage fuel flowing into the downstream fuel cavity in the first stage of the rotating flow vane through the second stage of the fuel guide pipe, then flowing into the first stage of the fuel hub cavity, and then flowing into the second stage of the rotating flow vane fuel cavity and being sprayed from the second stage of the fuel injection hole and being fully premixed with air downstream of the vane.

[0012] The coaxial staged combustion chamber head based on the sleeve type fuel supply and the supply method of the present application adopt the sleeve type fuel supply mode, which is different from the existing mode of supplying fuel through multiple independent fuel pipes which are spatially separated, and the above-mentioned technology of the present application uses the coaxially nested multi-stage fuel sleeve as the fuel supply sleeve, which can greatly improve the space utilization rate of the combustion chamber head, adopts the staged and zoned combustion mode, reduces pollutant emission, and prevents the head from being ablated.

[0013] According to the embodiment of the present application, the sleeve type fuel supply scheme is adopted, and the fuel double channel is arranged in the vane, which can effectively reduce the effective area of the combustion chamber occupied by the fuel transportation pipeline and improve the space utilization rate.

[0014] According to the embodiment of the present application, the coaxial staged form is adopted, which can realize the staged and zoned combustion, plays a role in stabilizing combustion, the outlet of each stage of the rotating flow device is located at different axial positions, the two stages of the hub are at a certain angle with the center axis, which can accelerate the airflow speed to prevent the end surface of the rotating flow device from being ablated, and the fuel is fully premixed in each stage of the rotating flow device, which can effectively reduce emission.

[0015] In addition, according to the embodiment of the present application, the central blunt body, the first-stage wheel hub and the second-stage wheel hub are coaxially nested from inside to outside, the first-stage wheel hub and the second-stage wheel hub are both tapered, and an integrated Venturi tube structure is arranged at the end of the first-stage wheel hub and the second-stage wheel hub, which can accelerate the airflow and push the flame to prevent backfire; meanwhile, the end Venturi tube structure realizes smooth transition and avoids the speed pressure mutation caused by geometric mutation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structure schematic diagram of a coaxial staged combustion chamber head based on a sleeve type fuel supply according to an embodiment of the present application;

[0017] Figure 2 is a first-stage swirl vane internal fuel cavity arrangement schematic diagram;

[0018] Figure 3 is a second-stage swirl vane internal fuel cavity arrangement schematic diagram;

[0019] Figure 4 is a schematic diagram of the fuel cavity and the fuel guide pipe;

[0020] Figure 5 is a front view of a coaxial staged combustion chamber head based on a sleeve type fuel supply according to a preferred embodiment of the present application;

[0021] Figure 6 is a rear view of a coaxial staged combustion chamber head based on a sleeve type fuel supply according to a preferred embodiment of the present application;

[0022] Figure 7 is a side view of a coaxial staged combustion chamber head based on a sleeve type fuel supply according to a preferred embodiment of the present application;

[0023] Figure 8 is a top view of a coaxial staged combustion chamber head based on a sleeve type fuel supply according to a preferred embodiment of the present application.

[0024] In the figure: 1: combustion chamber head; 1a: primary stage fuel conduit; 1b: central bluff body; 1c: axial fuel injection hole; 1d: inclined radial fuel injection hole; 2a: first stage fuel conduit; 2b: tapered section at the end of the first stage fuel conduit; 3: second stage fuel conduit; 4a: first stage hub; 4b: first stage hub fuel cavity; 5: second stage hub; 6a: first stage swirl vane; 6b: upstream fuel cavity within the first stage swirl vane; 6c: downstream fuel cavity within the first stage swirl vane; 6d: first stage fuel injection hole; 7a: second stage swirl vane; 7b: second stage swirl vane fuel cavity; 7c: second stage fuel injection hole; 8: fuel conduit inlet; 9: mainstream air inlet; 10: central axis of the swirler; β: included angle between the first stage hub tapered section and the central axis; γ: included angle between the second stage hub tapered section and the central axis. DETAILED DESCRIPTION

[0025] In order to make the personnel in the technical field better understand the present application, the exemplary embodiments or examples of the present application will be described in the following with reference to the accompanying drawings. Based on the embodiments in the present application, all other embodiments or examples obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present application.

[0026] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" shall be understood in a broad sense, for example, can be fixed connection, can also be detachable connection; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "above" and "on" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The "lower", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0028] Exemplary device

[0029] According to an embodiment of the present application, a coaxial staged combustion chamber head based on a cannula fuel supply is provided, which comprises a fuel supply cannula, a bluff body component, N-stage hubs, and N-stage swirl vanes; wherein N is an integer greater than or equal to 1; the fuel supply cannula comprises a multi-stage fuel cannula coaxially nested, the central conduit of the multi-stage fuel cannula is a duty stage fuel pipe; the central conduit is nested with N-stage conduits, the stage of the N-stage conduits increases successively from the outermost to the innermost; the multi-stage fuel cannula is provided with the bluff body component at the end thereof, the fuel cavity in the bluff body component is in communication with the central conduit of the multi-stage fuel cannula; the bluff body component is coaxially nested with the N-stage hubs, the stage number of each hub of the N-stage hubs increases successively from the innermost to the outermost; the end of the bluff body component and the end of each hub of the N-stage hubs are located at different positions on the same axial line; extending from the end of the central conduit along the axial line in the direction away from the fuel supply cannula, the end of the bluff body component, and the end of each hub of the N-stage hubs with successively increasing stage number are successively arranged; the N-stage swirl vanes comprise first-stage swirl vanes to N-stage swirl vanes; the first-stage swirl vanes are arranged between the bluff body component and the first-stage hub; the swirl vanes corresponding to the higher-stage hub are arranged between two adjacent hubs; N-i+1 fuel cavities are opened in the i-stage swirl vanes, and the i-stage fuel injection hole is arranged on the i-stage swirl vanes; one of the N-i+1 fuel cavities is used for communication with the i-stage fuel injection hole, and the remaining N-i fuel cavities are respectively used for communication with the fuel cavities of the downstream swirl vanes; wherein i=1, 2, …, N. Generally, the fuel injection hole on each swirl vane is located upstream of the flow channel.

[0030] Hereinafter, the coaxial staged combustion chamber head based on the cannula fuel supply according to the embodiment of the present application is described in detail. The coaxial staged combustion chamber head comprises a fuel supply cannula, a bluff body component, N-stage hubs, and N-stage swirl vanes.

[0031] Here, N is a natural number, for example, N can be equal to 2 or 3.

[0032] The fuel supply cannula comprises a multi-stage fuel cannula coaxially nested, the central conduit (i.e. the innermost conduit) of the multi-stage fuel cannula is a duty stage, that is, the central conduit is a duty stage fuel pipe.

[0033] The central conduit is nested with N-stage conduits, the stage of the N-stage conduits increases successively from the outermost to the innermost. That is, in addition to the innermost central conduit, the multi-stage fuel cannula successively from the outermost to the innermost is a first-stage fuel conduit, a second-stage fuel conduit, …, an N-stage fuel conduit.

[0034] It should be noted that in the embodiments of the present application, the first level is equivalent to the first level, and for the sake of convenience, the numbers represented by the Chinese characters of the first level, the second level, the third level, etc. are represented by Arabic numerals, such as the first level, the second level, the third level, etc. have the same meaning.

[0035] A bluff body component is provided at the end of the multi-stage fuel sleeve. It should be understood that the fuel supply sleeve (multi-stage fuel sleeve) has two ends, one end is the fuel inlet, the other end is the fuel outlet, and the end referred to here refers to the end corresponding to the fuel outlet.

[0036] The fuel cavity in the bluff body component is in communication with the central conduit of the multi-stage fuel sleeve.

[0037] The N-stage hub is coaxially nested outside the bluff body component, and the number of levels of the N-stage hub increases from the inside to the outside. That is, from the inside to the outside, it is the bluff body component, the first stage hub, the second stage hub, …, the N-stage hub.

[0038] The end of the bluff body component and the end of each level of the N-stage hub are located at different positions on the same axial line. From the end of the central conduit along the axial line in the direction away from the fuel supply sleeve, the end of the bluff body component, and the end of each level of the N-stage hub with increasing level number are sequentially arranged.

[0039] It should be understood that the bluff body component and the hub are coaxially arranged, so assuming that the direction of the axial line is from left to right (with one end of the straight line as the left side and the other end as the right side), taking the rightmost edge of the bluff body component and each level of the hub as their respective ends, then the order from left to right on the axial line is the end of the bluff body component, the end of the first stage hub, the end of the second stage hub, …, the end of the N-stage hub.

[0040] The N-stage swirl vane includes a first-stage swirl vane to an N-stage swirl vane.

[0041] Among them, the first-stage swirl vane is arranged between the bluff body component and the first-stage hub; the swirl vane corresponding to the higher level hub is arranged between the two adjacent level hubs.

[0042] That is, when i is equal to 1, the first-stage swirl vane is arranged between the bluff body component and the first-stage hub; when i is greater than 1, the i-stage swirl vane is arranged between the i-1-stage hub and the i-stage hub.

[0043] The i-stage swirl vane has N-i+1 fuel cavities, and the i-stage fuel injection hole is arranged on the i-stage swirl vane; one of the N-i+1 fuel cavities is used to communicate with the i-stage fuel injection hole, and the remaining N-i fuel cavities are used to communicate with the fuel cavities of the downstream swirl vane; wherein i = 1, 2, …, N.

[0044] As mentioned above, N can be any natural number, preferably, N can be 2 or 3. In the following, an implementation of the above-mentioned coaxial staged combustion chamber head based on the sleeve fuel supply will be described with N = 2 as an example. It should be understood that although the following mainly takes N = 2 as an example, embodiments of the present application are not limited thereto, in other embodiments of the present application, N can be equal to 3 or other natural numbers, which will not be described one by one here. Figures 1 to 4 An implementation of the above-mentioned coaxial staged combustion chamber head based on the sleeve fuel supply will be described with N = 2 as an example. It should be understood that although the following mainly takes N = 2 as an example, embodiments of the present application are not limited thereto, in other embodiments of the present application, N can be equal to 3 or other natural numbers, which will not be described one by one here.

[0045] As shown in Figure 1 , the fuel supply sleeve is a three-layer fuel conduit, including the on-duty fuel conduit 1a, the first-stage fuel conduit 2a and the second-stage fuel conduit 3. As shown in Figure 1 , it can be seen that the three-layer fuel conduit includes a center conduit and N-stage conduits nested outside the center conduit, here, N = 2, that is, the center conduit is the on-duty fuel conduit 1a, the two-stage conduits nested outside the center conduit include the first-stage fuel conduit 2a and the second-stage fuel conduit 3. Figure 1 Figure 1 Figure 1 As shown in , the three-layer fuel conduit is the first-stage fuel conduit 2a, the second-stage fuel conduit 3 and the on-duty fuel conduit 1a from outside to inside.

[0046] Figure 1 The bluff body component adopts the center bluff body 1b as shown in

[0047] The center bluff body 1b is coaxially nested with N-stage hubs outside, as shown in Figure 1 , the N-stage hub is a two-stage hub. The two-stage hub includes the first-stage hub 4a and the second-stage hub 5.

[0048] As shown in Figure 1 , the N-stage swirl vanes are two-stage swirl vanes, including the first-stage swirl vanes 6a and the second-stage swirl vanes 7a.

[0049] The center bluff body 1b is located at the end of the three-layer fuel conduit, and the fuel cavity in the center bluff body 1b is communicated with the on-duty fuel conduit 1a.

[0050] The center bluff body 1b is provided with the inclined radial fuel injection hole 1d and the axial fuel injection hole 1c. As an example, as shown in Figure 1 and Figure 4 , the center bluff body 1b is provided with a plurality of axial fuel injection holes 1c on the end face, and a plurality of inclined radial fuel injection holes 1d are uniformly arranged at a predetermined distance from the end face in the circumferential direction. The inclined radial direction of the inclined radial fuel injection hole 1d is perpendicular to the slope surface of the center bluff body 1b. The shape of the center bluff body 1b is, for example, part of a cone, which is divided into two parts by a cross section parallel to the bottom surface, one part containing the vertex of the cone and the other part not containing the vertex of the cone, and the center bluff body 1b is formed in the shape of the part not containing the vertex of the cone, for example.​​

[0051] In addition, the center bluff body 1b, the first stage hub 4a and the second stage hub 5 are coaxially nested in order from inside to outside, and in order from left to right along the center axis 10, which are the end of the center bluff body 1b, the end of the first stage hub 4a and the end of the second stage hub 5 in order.

[0052] The first stage hub 4a is provided with a first stage hub fuel cavity 4b inside, as shown in Figure 4 .

[0053] The first stage swirl vane 6a is located between the center bluff body 1b and the first stage hub 4a.

[0054] The first stage swirl vane 6a is provided with two fuel cavities inside, which are the upstream fuel cavity 6b and the downstream fuel cavity 6c, as shown in Figure 2 . Referring to Figure 1 , the windward side and the leeward side of the first stage swirl vane 6a are both provided with the first stage fuel injection hole 6d, and the first stage fuel injection hole 6d is communicated with the upstream fuel cavity 6b.

[0055] As shown in Figure 1 , the second stage swirl vane 7a is located between the first stage hub 4a and the second stage hub 5, adopts NACA-9612 airfoil, and is provided with a fuel cavity 7b inside, and the windward side and the leeward side of the vane are provided with the second stage fuel injection hole 7c, which is communicated with the fuel cavity 7b.

[0056] As an example, the first stage swirl vane 6a and the second stage swirl vane 7a can be any one of straight blade, curved blade or airfoil blade, for example, NACA-9612 airfoil blade as shown in Figure 1 .

[0057] As an example, the end of the first stage fuel guide pipe 2a is a tapered section 2b, which extends to the upstream fuel cavity 6b inside the first stage swirl vane 6a. In addition, the second stage fuel guide pipe 3 extends to the downstream fuel cavity 6c inside the first stage swirl vane 6a.

[0058] As an example, the fuel supply sleeve is turned 0-90° after being led out of the swirler and connected with the combustion chamber outer fuel pipeline (located near the fuel guide pipe inlet 8 as shown in Figure 1 .

[0059] Preferred embodiment

[0060] As shown in Figure 1A coaxial staged combustor head based on sleeve fuel supply is shown, which comprises: a duty stage fuel conduit 1a, a first stage fuel conduit 2a, a second stage fuel conduit 3, a center bluff body 1b, a first stage hub 4a, a second stage hub 5, a first stage swirler vane 6a and a second stage swirler vane 7a. The head is an integrated structure as a whole. In addition, Figures 5 to 8 respectively, are the front view, rear view, side view and top view of the coaxial staged combustor head based on sleeve fuel supply of the present embodiment.

[0061] Referring to Figures 1 to 4 , the duty stage fuel conduit 1a, the first stage fuel conduit 2a and the second stage fuel conduit 3 are coaxially nested and distributed, and the order from inside to outside is: the duty stage fuel conduit 1a, the second stage fuel conduit 3 and the first stage fuel conduit 2a; the center bluff body 1b is located at the end of the three fuel conduits, and has a fuel cavity inside and communicates with the duty stage fuel conduit 1a, and the center bluff body 1b is provided with an oblique radial fuel injection hole 1d and an axial fuel injection hole 1c; as shown in Figure 4 , the end of the first stage fuel conduit 2a is a tapered section 2b, which can effectively reduce flow loss and space occupied, and the tapered section 2b extends to the corresponding upstream fuel cavity 6b in the first stage swirler vane 6a; the second stage fuel conduit 3 extends to the downstream fuel cavity 6c.

[0062] The center bluff body 1b, the first stage hub 4a and the second stage hub 5 are coaxially nested and distributed in order from inside to outside, and the ends of the hubs are not at the same axial position, and the order from left to right along the swirler center axis 10 is: the end of the center bluff body 1b, the end of the first stage hub 4a and the end of the second stage hub 5, which can prevent the duty stage from being ablated and stabilize combustion; the first stage hub 4a is provided with a first stage hub fuel cavity 4b inside.

[0063] The first stage swirler vane 6a is located between the center bluff body 1b and the first stage hub 4a, for example, using NACA-9612 airfoil, and two fuel cavities are opened in the vane, which are the upstream fuel cavity 6b and the downstream fuel cavity 6c, and the first stage swirler vane 6a is provided with the first stage fuel injection hole 6d on the windward side and the leeward side, and the first stage fuel injection hole 6d communicates with the upstream fuel cavity 6b of the vane.

[0064] The second stage swirler vane 7a is located between the first stage hub 4a and the second stage hub 5, for example, using NACA-9612 airfoil, and a second stage swirler vane fuel cavity 7b is opened in the vane, and the second stage swirler vane 7a is provided with the second stage fuel injection hole 7c on the windward side and the leeward side, and the second stage fuel injection hole 7c communicates with the second stage swirler vane fuel cavity 7b.

[0065] The fuel conduit (i.e. fuel supply sleeve) is bent by 0-90° (for example Figure 1The outer diameter of the first stage fuel guide pipe 2a is for example 30% to 35% of the outer diameter of the three-layer sleeve, and the outer diameter of the second stage fuel guide pipe 3 is for example 65% to 75% of the outer diameter of the three-layer sleeve, and the wall thickness is for example 1mm to 1.2mm. There are for example 4 to 7 axial fuel injection holes 1c on the end face of the central bluff body 1b, and there are for example 4 to 6 circumferentially uniform inclined radial fuel injection holes 1d at a distance of 5 to 8mm from the end face. The fuel hole (axial fuel injection hole 1c and inclined radial fuel injection hole 1d) hole diameter is for example 1mm to 1.5mm, which prevents the first stage from ablation.

[0066] The length of the first stage hub fuel cavity 4b in the first stage hub 4a is for example 75% to 85% of the total length of the hub, and the minimum wall thickness is for example greater than 1mm (such as 2mm) to ensure structural strength. The angle between the tapered section of the first stage hub 4a and the central axis 10 is β, and the angle between the tapered section of the second stage hub 5 and the central axis 10 is γ, and the value range of β and γ is for example 30° to 60°, which increases the head intake to reduce emissions, and increases the airflow velocity to prevent backfire.

[0067] The number of first stage swirl vanes 6a is for example 6 to 8, and the number of second stage swirl vanes 7a is for example 12 to 16. Each vane of the first stage swirl vanes 6a and the second stage swirl vanes 7a is arranged with for example 3 fuel injection holes on the windward side and the leeward side, and the hole diameter is for example 0.6 to 1mm.

[0068] The shapes of the swirl vane fuel cavities 6b, 6c, 7b are consistent with the shapes of the vanes. As shown in Figure 2 and Figure 3 The shape of the combination of the upstream fuel cavity 6b and the downstream fuel cavity 6c in the first stage swirl vane 6a is consistent with the shape of the first stage swirl vane 6a, and the shape of the second stage swirl vane fuel cavity 7b in the second stage swirl vane 7a is consistent with the shape of the second stage swirl vane 7a.

[0069] The upstream fuel cavity 6b in the first stage swirl vane 6a is communicated with the first stage fuel guide pipe 2a, and the downstream fuel cavity 6c in the first stage swirl vane 6a is communicated with the second stage fuel guide pipe 3, the first stage hub fuel cavity 4b and the second stage swirl vane fuel cavity 7b, and the minimum wall thickness is greater than 1mm (for example 2mm) to ensure the strength of the vane.

[0070] The coaxial staged combustion chamber head based on the sleeve type fuel supply of the application comprises a duty class fuel conduit, a first stage fuel conduit, a second stage fuel conduit, a center bluff body, a first stage hub, a second stage hub, a first stage swirl vane, a second stage swirl vane; the fuel conduit, the hub and the swirl vane are integrated; the first stage, the second stage and the duty class fuel conduit are coaxially nested from outside to inside, the center bluff body is located at the end of the three layers of sleeve and communicates with the duty class fuel conduit; the center bluff body, the first stage hub and the second stage hub are coaxially nested and distributed from inside to outside, the first stage hub and the second stage hub are both tapered and are provided with an integrated venturi structure at the end, and the first stage hub is provided with a fuel ring cavity; the first stage swirl vane is provided with two fuel cavities, an upstream fuel cavity communicates with the first stage fuel conduit and delivers fuel to the flow channel where the first stage vane is located, and a downstream fuel cavity communicates with the second stage fuel conduit, the first stage hub ring cavity and the second stage swirl vane fuel cavity and delivers fuel to the flow channel where the second stage vane is located. The coaxial staged combustion chamber head based on the sleeve type fuel supply of the application can effectively save the space of the combustion chamber occupied by the fuel supply and improve the space utilization rate of the combustion chamber; the staged and partitioned combustion mode can reduce pollutant emission and prevent head ablation.

[0071] Exemplary method

[0072] According to another aspect of the application, a fuel supply method using the coaxial staged combustion chamber head based on the sleeve type fuel supply is also provided, the method comprising: all fuel entering the head through the fuel conduit inlet 8, main flow air entering the flow channel where the swirl vane (including the first stage swirl vane 6a and the second stage swirl vane 7a) is located through the main flow air inlet 9; the duty class fuel / air (i.e. working medium in the following text) is sprayed out from the oblique radial fuel injection hole 1d and the axial fuel injection hole 1c on the center bluff body 1b through the duty class fuel conduit 1a. The oblique radial fuel injection hole 1d and the axial fuel injection hole 1c are both the fuel injection holes of the duty class.

[0073] When the duty class works, the working medium transported by the duty class fuel conduit 1a is fuel for low working conditions; conversely, when the duty class does not work, the working medium transported by the duty class fuel conduit 1a is air to prevent ablation of the center bluff body 1b.

[0074] The first stage fuel flows into the upstream fuel cavity 6b in the first stage swirl vane 6a through the first stage fuel conduit 2a and is sprayed out from the first stage fuel injection hole 6d to be fully premixed with air downstream of the first stage swirl vane 6a; the second stage fuel flows into the downstream fuel cavity 6c in the first stage swirl vane 6a through the second stage fuel conduit 3, then flows into the first stage hub fuel cavity 4b and then flows into the second stage swirl vane fuel cavity 7b, and is sprayed out from the second stage fuel injection hole 7c to be fully premixed with air downstream of the second stage swirl vane 7a.

[0075] While the application has been described in accordance with a limited number of embodiments, these are merely illustrative of the many possible embodiments of the application. Other embodiments can be devised without departing from the scope of the application as described herein. Alternative embodiments will be obvious to those of ordinary skill in the art in view of the foregoing description. The only true measure of the scope of the application is the appended claims.

Claims

1. A coaxial staged combustion chamber head based on cannula fuel supply, characterized in that, The coaxial staged combustion chamber head comprises a fuel supply sleeve, a bluff body component, an N-stage wheel hub and an N-stage swirl vane; wherein N is an integer greater than 1; The fuel supply sleeve comprises a plurality of fuel conduits coaxially nested, the center conduit of the plurality of fuel conduits is a duty stage fuel conduit; the center conduit is nested with N-stage conduits, the stage number of the N-stage conduits increases from the outermost to the innermost; The end of the plurality of fuel conduits is provided with the bluff body component, the fuel cavity in the bluff body component is communicated with the center conduit of the plurality of fuel conduits; The bluff body component is coaxially nested with the N-stage wheel hub, the stage number of the N-stage wheel hub increases from the innermost to the outermost; The end of the bluff body component and the end of each stage of the N-stage wheel hub are located at different positions on the same axial line; from the end of the center conduit to the end of each stage of the N-stage wheel hub along the axial line in the direction away from the fuel supply sleeve, the end of the bluff body component, the end of each stage of the N-stage wheel hub with the increasing stage number are sequentially arranged; The N-stage swirl vane comprises a first-stage swirl vane to an N-stage swirl vane; the first-stage swirl vane is arranged between the bluff body component and the first-stage wheel hub; the swirl vane corresponding to the higher stage number is arranged between two adjacent stages of the wheel hub; No. i N- i +1 fuel chambers, and the first i The first stage swirl blade is equipped with the second stage. i Stage fuel injection orifice; the N- i +1 fuel chamber is used to connect with the first i The first-stage fuel injection holes are interconnected, while the remaining N- i Each of the three chambers is connected to the fuel chamber of the downstream swirl blades; among them, i =1,2,…,N.

2. A cannula-based fuel supply based coaxial staged combustion chamber head according to claim 1, characterized in that N=2； The fuel supply sleeve is a three-layer fuel conduit, comprising a duty stage fuel conduit (1a), a first-stage fuel conduit (2a) and a second-stage fuel conduit (3); the bluff body component is a center bluff body (1b); the N-stage wheel hub comprises a first-stage wheel hub (4a) and a second-stage wheel hub (5); the N-stage swirl vane comprises a first-stage swirl vane (6a) and a second-stage swirl vane (7a); The duty stage fuel conduit (1a), the second-stage fuel conduit (3) and the first-stage fuel conduit (2a) are coaxially nested from the innermost to the outermost; The center bluff body (1b) is located at the end of the three-layer fuel conduit, the fuel cavity in the center bluff body (1b) is communicated with the duty stage fuel conduit (1a), the center bluff body (1b) is provided with an inclined radial fuel injection hole (1d) and an axial fuel injection hole (1c); The center bluff body (1b), the first-stage wheel hub (4a) and the second-stage wheel hub (5) are coaxially nested from the innermost to the outermost, and sequentially arranged along the center axis (10) from left to right as the end of the center bluff body (1b), the end of the first-stage wheel hub (4a) and the end of the second-stage wheel hub (5); the first-stage wheel hub (4a) is provided with a first-stage wheel hub fuel cavity (4b); The first-stage swirl vane (6a) is located between the center bluff body (1b) and the first-stage wheel hub (4a), two fuel cavities are formed in the first-stage swirl vane (6a), which are an upstream fuel cavity (6b) and a downstream fuel cavity (6c); the windward side and the leeward side of the first-stage swirl vane (6a) are provided with a first-stage fuel injection hole (6d), the first-stage fuel injection hole (6d) is communicated with the upstream fuel cavity (6b); The second stage rotating flow vane (7a) is located between the first stage hub (4a) and the second stage hub (5), and the second stage rotating flow vane is provided with a second stage rotating flow vane fuel cavity (7b) and a second stage fuel injection hole (7c) on the windward side and the leeward side of the vane.

3. The coaxial staged combustion chamber head based on the sleeve fuel supply according to claim 2, characterized in that, The first stage fuel guide pipe (2a) is provided with a tapered section (2b) at the end, which extends to the upstream fuel cavity (6b) in the first stage rotating flow vane (6a); the second stage fuel guide pipe (3) extends to the downstream fuel cavity (6c) in the first stage rotating flow vane (6a).

4. A cannula-based fuel supply based coaxial staged combustion chamber head according to claim 2 or 3, characterized in that The fuel supply sleeve is bent by 0-90° after being led out of the swirler and connected with the combustion chamber outer fuel pipeline; the end surface of the center bluff body (1b) is provided with a plurality of axial fuel injection holes (1c) and a plurality of circumferentially uniformly arranged inclined radial fuel injection holes (1d) at a predetermined distance from the end surface.

5. A cannula-based fuel supply based coaxial staged combustion chamber head according to claim 2 or 3, characterised in that, The length of the first stage hub fuel cavity (4b) accounts for 75% to 85% of the total length of the hub, and the minimum wall thickness is greater than 1mm to ensure the structural strength; the included angle between the tapered section of the first stage hub (4a) and the central axis (10) of the swirler is β , the included angle between the tapered section of the second stage hub (5) and the central axis (10) is γ , β and γ , the value range is 30° to 60°.

6. A cannula-based fuel supply based coaxial staged combustion chamber head according to claim 2 or 3, characterized in that The number of the first stage rotating flow vanes (6a) is 6-8, and the number of the second stage rotating flow vanes (7a) is 12-16; three fuel injection holes are arranged on the windward side and the leeward side of each vane; the shape of the combination of the upstream fuel cavity (6b) and the downstream fuel cavity (6c) in the first stage rotating flow vane (6a) is consistent with the shape of the first stage rotating flow vane (6a), and the shape of the second stage rotating flow vane fuel cavity (7b) in the second stage rotating flow vane (7a) is consistent with the shape of the second stage rotating flow vane (7a); the upstream fuel cavity (6b) is communicated with the first stage fuel guide pipe, and the downstream fuel cavity (6c) is communicated with the second stage fuel guide pipe, the first stage hub fuel cavity and the second stage rotating flow vane fuel cavity (7b).

7. A method of fuel supply using the coaxial staged combustion chamber head based on the sleeve fuel supply according to any one of claims 1 to 6, characterized by, The method comprises: All the fuel enters the head through the fuel guide pipe inlet (8), and the main stream air enters the flow channel where the rotating flow vanes are located through the main stream air inlet (9); the standby stage fuel or air is sprayed out through the inclined radial fuel injection holes (1d) and the axial fuel injection holes (1c) on the center bluff body (1b) through the standby stage fuel guide pipe (1a); when the standby stage works, the transported working medium is fuel, and vice versa, so as to prevent the ablation of the center bluff body (1b); the first stage fuel flows into the upstream fuel cavity (6b) in the first stage rotating flow vane (6a) through the first stage fuel guide pipe (2a), and is sprayed out through the first stage fuel injection hole (6d) to be fully premixed with air downstream of the vane; the second stage fuel flows into the downstream fuel cavity (6c) in the first stage rotating flow vane (6a) through the second stage fuel guide pipe (3), and then flows into the first stage hub fuel cavity (4b) and the second stage rotating flow vane fuel cavity (7b), and is sprayed out through the second stage fuel injection hole (7c) to be fully premixed with air downstream of the vane.

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