Main combustion stage fuel injection assembly, staged combustion chamber and aircraft engine

Abstract

The embodiment of the present application discloses a main combustion stage fuel injection assembly, a staged combustion chamber and an aircraft engine. The main combustion stage fuel injection assembly includes a main combustion stage outer wall, a main combustion stage inner wall and a main combustion stage fuel injection member. The main combustion stage outer wall includes a first outer portion and a second outer portion; the main combustion stage outer wall includes a first inner portion and a second inner portion, the main combustion stage inner wall is spaced apart and arranged on the inner side of the main combustion stage outer wall, a swirl channel is formed between the first inner portion and the first outer portion, and a main combustion stage channel is formed between the second inner portion and the second outer portion, and the main combustion stage channel has a channel opening; the main combustion stage fuel injection member includes a first injection section and a second injection section, an outer swirl blade is arranged between the first injection section and the first outer portion, and an inner swirl blade is arranged between the first injection section and the first inner portion; the main combustion stage fuel injection member is provided with a jet channel, and the jet port of the jet channel is arranged toward the channel opening. The jet port of the main combustion stage fuel injection member can be arranged close to the channel opening, thereby reducing the problems of spontaneous combustion or backfire of the fuel in the main combustion stage channel.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of engines, and in particular to a main combustion stage fuel injection assembly, a staged combustion chamber, and an aircraft engine. Background Art

[0002] The combustion chamber is called the "heart" of an aircraft engine. Its main function is to convert the chemical energy of the fuel into thermal energy through combustion, and then discharge the high-temperature combustion gas to impact the turbine.

[0003] In related technologies, the combustion chamber is divided into two combustion zones: the central pre-stage combustion zone, which typically operates in a diffusion combustion mode; and the peripheral main-stage combustion zone. Under high-power engine operation, the main-stage fuel supply ratio is much greater than the pre-stage fuel ratio. The main-stage fuel and airflow can be premixed, and the premixed main-stage fuel is injected into the main-stage combustion zone of the combustion chamber. This premixed main-stage fuel helps achieve uniform combustion of the main-stage fuel, reducing pollutant emissions and the outlet temperature distribution coefficient.

[0004] The combustion chamber is provided with a main combustion stage fuel injection assembly, which is used to inject main combustion stage fuel into the main combustion zone. Specifically, a main combustion stage channel is provided on the inner side of the main combustion stage fuel injection assembly, and an injection channel is provided on the inner side wall of the main combustion stage channel, which extends to the inner circumference. The main combustion stage fuel injection assembly injects the main combustion stage fuel toward the outer side wall of the main combustion stage channel through the injection channel to achieve lateral cross-flow injection of the main combustion stage fuel in the main combustion stage channel. The main combustion stage channel is provided with a premixing structure, such as a main combustion stage pre-film plate provided on the main combustion stage fuel injection path or a premixing section provided at the opening position of the main combustion stage channel. Therefore, the premixing structure allows the main combustion stage fuel to be fully premixed in the main combustion stage channel.

[0005] However, in current and foreseeable future high-performance aircraft engines, compressor pressure ratios will reach 50 or higher, and combustion inlet temperatures will exceed 900 calvins. Fuel and air contact can quickly lead to spontaneous combustion and backfire, requiring the main stage premixing passages to be shortened or even eliminated. In such harsh operating environments, fuel in the tiny nozzles is prone to coking and clogging. These issues pose significant challenges to the combustion mechanism, structural design, and thermal protection of the combustor. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a main stage fuel injection assembly, a staged combustion chamber, and an aircraft engine that can reduce the risk of spontaneous combustion or flashback of the main stage fuel in the main stage passage, thereby ensuring safe operation.

[0007] In a first aspect, an embodiment of the present application provides a main combustion stage fuel injection assembly, comprising a main combustion stage outer wall, a main combustion stage inner wall, and a main combustion stage fuel injection member, wherein:

[0008] The outer wall of the main combustion stage is arranged in an annular shape, and the outer wall of the main combustion stage includes at least a first outer portion and a second outer portion connected to each other in the longitudinal direction;

[0009] The main combustion stage inner wall is annularly arranged, and the main combustion stage outer wall includes at least a first inner portion and a second inner portion connected to each other in the longitudinal direction. The main combustion stage inner wall is spaced apart and coaxially arranged on the inner side of the main combustion stage outer wall; wherein a swirl channel is formed between the first inner portion and the first outer portion, and a main combustion stage channel is formed between the second inner portion and the second outer portion, and a port of the main combustion stage channel away from the swirl channel is a channel port for communicating with the combustion chamber;

[0010] The main combustion stage fuel injection member is arranged in an annular shape, and the main combustion stage fuel injection member is spaced and arranged between the main combustion stage outer wall and the main combustion stage inner wall, and is arranged coaxially. The main combustion stage fuel injection member includes at least a first injection section and a second injection section connected in the longitudinal direction, the first injection section is located in the swirl channel, an outer swirl blade is provided between the first injection section and the first outer portion, an inner swirl blade is provided between the first injection section and the first inner portion, and the second injection section is located in the main combustion stage channel;

[0011] In which, the main combustion stage fuel injection component is provided with an injection channel, the injection channel forms an oil inlet in the first injection section, the injection channel forms an injection port at one end of the second injection section away from the first injection section, the distance between the injection port and the first interior is consistent with the distance between the injection port and the first exterior, and the injection port is arranged toward the channel opening so that the main combustion stage fuel injection component can spray fuel into the combustion chamber through the channel opening.

[0012] According to some embodiments of the present invention, the injection channel includes an injection hole, which forms the injection port at the end of the second injection section. The axial direction of the injection hole is inclined relative to the axial direction of the main combustion stage fuel injection part so that the injection angle of the injection port matches the airflow direction of the main combustion stage channel.

[0013] According to some embodiments of the present invention, the injection channel includes an oil collecting tank and a plurality of injection holes;

[0014] The main stage fuel injection element is provided with an annular oil collecting groove around the central axis, and the distance between the oil collecting groove and the first inner portion is consistent with the distance between the oil collecting groove and the first outer portion;

[0015] The second injection section is provided with a plurality of injection holes spaced apart around the central axis, each of the injection holes is connected to the end of the oil collecting tank close to the channel opening, and the injection port is formed at the end of the second injection section, and the diameter of the injection hole is set between 0.1 mm and 1 mm.

[0016] According to some embodiments of the present invention, the main combustion stage fuel injection component has an inner portion and an outer portion, and the oil collecting groove is formed between the inner portion and the outer portion; wherein the thickness of the inner portion is consistent with the thickness of the outer portion and is between 0.5 mm and 5 mm.

[0017] According to some embodiments of the present invention, the distance between the injection port and the channel port is set between 0 mm and 100 mm.

[0018] According to some embodiments of the present invention, the main combustion stage fuel injection assembly further includes a first annular sleeve, the first annular sleeve is arranged on the outer side of the main combustion stage fuel injection member, the outer swirl blade is arranged between the first annular sleeve and the first outer portion, and the circumferential surface of the main combustion stage fuel injection member is provided with a first boss, the first boss abuts against an end of the first annular sleeve away from the main combustion stage channel;

[0019] And / or, the main combustion stage fuel injection assembly also includes a second ring sleeve, the main combustion stage fuel injection part is sleeved on the outside of the second ring sleeve, the inner swirl blade is arranged between the second ring sleeve and the first inner part, and the circumferential surface of the main combustion stage fuel injection part is provided with a second boss, and the second boss is supported on the end of the second ring sleeve away from the main combustion stage channel.

[0020] According to some embodiments of the present invention, the main combustion stage channel includes at least a contraction section, a connecting portion, and an expansion section through which the airflow passes in sequence, and the connecting portion is arranged between the contraction section and the expansion section, wherein, along the axial direction toward the channel opening, the inner diameter of the contraction section of the main combustion stage channel gradually decreases, and the inner diameter of the expansion section gradually increases, and the injection port is located on the inner side of one of the contraction section, the connecting portion, and the expansion section.

[0021] According to some embodiments of the present invention, the main combustion stage fuel injection assembly also includes an intermediate connecting piece for connecting the pre-combustion stage fuel injection assembly, the intermediate connecting piece is connected to the end of the inner wall of the main combustion stage close to the channel mouth, the intermediate connecting piece is provided with a cooling channel, one end of the cooling channel is connected to at least the connecting portion, and the other end is connected to the end of the intermediate connecting piece away from the combustion chamber.

[0022] In a second aspect, an embodiment of the present application provides a staged combustion chamber with downstream injection of a main combustion stage, comprising:

[0023] A housing assembly, the housing assembly comprising a combustion chamber outer housing and a combustion chamber inner housing, the combustion chamber inner housing being disposed inside the combustion chamber outer housing, the combustion chamber inner housing inner housing having a vent hole communicating with the combustion chamber;

[0024] The main combustion stage fuel injection assembly is arranged at the air inlet of the combustion chamber casing;

[0025] A pre-combustion stage fuel injection assembly, the pre-combustion stage fuel injection assembly being arranged inside the main combustion stage fuel injection assembly and being coaxially arranged;

[0026] A fuel delivery assembly, the fuel delivery assembly being arranged in the outer casing of the combustion chamber and being used for delivering fuel to the main combustion stage fuel injection assembly and to the pre-combustion stage fuel injection assembly;

[0027] A diffuser is provided at the air inlet of the outer casing of the combustion chamber.

[0028] In a third aspect, an embodiment of the present application provides an aircraft engine, comprising:

[0029] low-pressure compressor;

[0030] a high-pressure compressor, wherein an air inlet of the high-pressure compressor is connected to an air outlet of the low-pressure compressor;

[0031] The above-mentioned staged combustion chamber, wherein the air inlet of the staged combustion chamber is connected to the air outlet of the high-pressure compressor;

[0032] a high-pressure turbine, wherein an air inlet of the high-pressure turbine is connected to an air outlet of the staged combustion chamber;

[0033] A low-pressure turbine, wherein the air inlet of the low-pressure turbine is connected to the air outlet of the high-pressure turbine.

[0034] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages: 1. The main combustion stage fuel injection assembly uses a downstream injection method to inject fuel into the combustion chamber, and while ensuring that the fuel can be better premixed with the two airflows before reaching the main combustion stage flame zone, the injection port of the main combustion stage fuel injection component can be set close to the channel port, reducing the problems of spontaneous combustion or backfire of the fuel in the main combustion stage channel, and even in high-temperature and high-pressure combustion chambers, the safe use of the main combustion stage fuel injection assembly can be guaranteed. 2. The present application removes the premixing structure and instead opens a spray channel on the inner wall of the main combustion stage. Therefore, the overall structure of the main combustion stage fuel injection assembly of the present application is relatively simple, the manufacturing cost is low, and it has the advantages of long service life. 3. The oil collecting tank structure avoids the fuel from heating up too quickly, and only uses a short spray hole at the end of the oil circuit. The overall thermal protection performance is excellent, which greatly reduces the risk of fuel coking and is suitable for application in high-temperature and high-pressure combustion chambers. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0036] Figure 1 An axial cross-sectional view of a main combustion stage fuel injection assembly according to an embodiment of the present invention;

[0037] Figure 2 for Figure 1 Schematic diagram of the middle part structure;

[0038] Figure 3 This is a partial structural diagram of the main combustion stage fuel injection assembly in an embodiment of the present invention;

[0039] Figure 4 A transverse cross-sectional view of a main combustion stage fuel injection component according to an embodiment of the present invention;

[0040] Figure 5 An axial cross-sectional view of a main combustion stage fuel injection component according to an embodiment of the present invention;

[0041] Figure 6 Schematic diagram of the structure of the staged combustion chamber in an embodiment of the present invention;

[0042] Figure 7 Schematic diagram of the structure of an aircraft engine in an embodiment of the present invention.

[0043] Figures: 10, low-pressure compressor; 20, high-pressure compressor; 30, staged combustion chamber; 40, high-pressure turbine; 50, low-pressure turbine; 100, main combustion stage fuel injection assembly; 110, main combustion stage outer wall; 111, first outer wall; 112, second outer wall; 120, main combustion stage inner wall; 121, first inner wall; 122, second inner wall; 130, main combustion stage fuel injection element; 131, first injection section; 132, second injection section; 133, injection channel; 1331, oil collecting tank; 1332, injection hole; 1333, injection port; 1334, oil inlet; 134, inner wall Side; 135, outer side; 136, first boss; 140, swirl channel; 141, inner swirl blade; 142, outer swirl blade; 150, main combustion stage channel; 151, channel opening; 152, contraction section; 153, expansion section; 154, connection; 160, intermediate connection; 161, cooling channel; 170, first ring sleeve; 200, shell assembly; 210, combustion chamber outer casing; 220, combustion chamber inner casing; 221, air vent; 222, combustion chamber; 300, pre-combustion stage injection assembly; 400, fuel delivery assembly; 500, diffuser. DETAILED DESCRIPTION

[0044] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0045] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0046] In the description of the present invention, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0047] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0048] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0049] This application discloses a main combustion stage fuel injection assembly 100, referring to Figures 1 to 3 , including a main combustion stage outer wall 110, a main combustion stage inner wall 120 and a main combustion stage oil injection part 130, wherein:

[0050] The main combustion stage outer wall 110 is annular and includes at least a first outer portion 111 and a second outer portion 112 connected to each other in the longitudinal direction;

[0051] The main combustion stage inner wall 120 is arranged in an annular shape, and the main combustion stage outer wall 110 includes at least a first inner portion 121 and a second inner portion 122 connected to each other in the longitudinal direction. The main combustion stage inner wall 120 is arranged at intervals on the inner side of the main combustion stage outer wall 110 and is coaxially arranged; wherein, a swirl channel 140 is formed between the first inner portion 121 and the first outer portion 111, and a main combustion stage channel 150 is formed between the second inner portion 122 and the second outer portion 112. The port of the main combustion stage channel 150 away from the swirl channel 140 is used to connect to the combustion chamber 222 (refer to Figure 6 ) connected to the channel opening 151;

[0052] The main combustion stage fuel injection member 130 is arranged in an annular shape. The main combustion stage fuel injection member 130 is spaced and arranged between the main combustion stage outer wall 110 and the main combustion stage inner wall 120, and is arranged coaxially. The main combustion stage fuel injection member 130 includes at least a first injection section 131 and a second injection section 132 connected in the longitudinal direction. The first injection section 131 is located in the swirl channel 140. An outer swirl blade 142 is provided between the first injection section 131 and the first outer portion 111. An inner swirl blade 141 is provided between the first injection section 131 and the first inner portion 121. The second injection section 132 is located in the main combustion stage channel 150.

[0053] Among them, the main combustion stage fuel injection element 130 is provided with an injection channel 133, the injection channel 133 forms an oil inlet 1334 in the first injection section 131, and the injection channel 133 forms an injection port 1333 at one end of the second injection section 132 away from the first injection section 131, and the distance between the injection port 1333 and the first inner portion 121 is consistent with the distance between the injection port 1333 and the first outer portion 111, and the injection port 1333 is set toward the channel port 151, so that the main combustion stage fuel injection element 130 can spray fuel into the combustion chamber 222 through the channel port 151.

[0054] It should be noted that the main combustion stage fuel injection component 130 divides the swirl channel 140 into two, and one swirl channel 140 is formed between the main combustion stage fuel injection component 130 and the first outer portion 111. In the circumferential direction of the swirl channel 140, a plurality of outer swirl blades 142 are arranged at intervals in the swirl channel 140, and a spiral channel for airflow is formed between adjacent outer swirl blades 142. A part of the airflow can flow into the main combustion stage channel 150 from the spiral channel between adjacent outer swirl blades 142, and the airflow flows in a spiral manner; similarly, another swirl channel 140 is formed between the main combustion stage fuel injection component 130 and the first inner portion 121. In the circumferential direction of the swirl channel 140, a plurality of inner swirl blades 141 are arranged at intervals in the swirl channel 140, and a spiral channel for airflow is formed between adjacent inner swirl blades 141. Another part of the airflow can flow into the main combustion stage channel 150 from the spiral channel between adjacent inner swirl blades 141, and the airflow flows in a spiral manner.

[0055] Specifically, the pressurized airflow enters the swirl channel 140 from the air inlet at the rear end of the swirl channel 140, wherein a portion of the airflow enters the swirl channel 140 between the main combustion stage fuel injector 130 and the first outer portion 111, and flows into the main combustion stage channel 150 along the outer swirl blades 142 to form a spiral channel. This portion of the airflow flows in a spiral manner toward the channel opening 151, and flows through the channel opening 151 to the main combustion stage flame zone of the combustion chamber 222. Similarly, another portion of the airflow enters the swirl channel 140 between the main combustion stage fuel injector 130 and the first inner portion 121, and flows into the main combustion stage channel 150 along the inner swirl blades 141 to form a spiral channel. This portion of the airflow flows in a spiral manner toward the channel opening 151, and flows through the channel opening 151 to the main combustion stage flame zone of the combustion chamber 222. At the same time, the external fuel delivery assembly 400 injects fuel into the injection channel 133 of the main combustion stage fuel injector 130 through the oil inlet 1334, and the fuel is ejected from the injection port 1333. Furthermore, since the injection port 1333 is disposed toward the channel opening 151 , the fuel injected from the injection port 1333 is injected into the combustion chamber 222 in a downstream manner.

[0056] Referring to the main stage fuel injection assembly described in the background art, a main stage pre-film plate and pre-mixing section are located inside the main stage channel. Fuel is injected into the main stage pre-film plate using a transverse cross-flow method and then enters the combustion chamber through the pre-mixing section. Due to this structure, the injection port needs to be positioned relatively far from the opening of the main stage channel, which can easily lead to problems such as natural combustion within the main stage channel.

[0057] Compared with the prior art, the present application adopts the main combustion stage fuel injection assembly 100 of the above-mentioned structural form, and the injection port 1333 is arranged toward the channel port 151, and the fuel is injected into the combustion chamber 222 in a downstream injection manner; in addition, the fuel ejected from the injection port 1333 is located between the above-mentioned two airflows, namely the airflow flowing out from the outer swirl blade 142 and the airflow flowing out from the inner swirl blade 141. Specifically, the two airflows are formed when the airflow passes through the inner swirl blade 141 and the outer swirl blade 142 and enters the main combustion stage channel 150; and, the injection port 1333 is located at the center of the main combustion stage channel 150, and the fuel ejected from the injection port 1333 is located at the center of the main combustion stage channel 150. Therefore, the fuel ejected from the injection port 1333 is located both between the two airflows and at the center of the main combustion stage channel 150. Before the fuel reaches the main combustion stage flame zone, the fuel and the two airflows can be better premixed, thereby ensuring that the fuel can be fully burned when it reaches the main combustion stage flame zone.

[0058] As can be seen from the above, the main combustion stage fuel injection assembly 100 uses a downstream injection method to inject fuel into the combustion chamber, and while ensuring that the fuel can be better premixed with the two airflows before reaching the main combustion stage flame zone, the injection port 1333 of the main combustion stage fuel injection component 130 can be set close to the channel port 151, reducing the problem of spontaneous combustion or backfire of the fuel in the main combustion stage channel 150, and the safe use of the main combustion stage fuel injection assembly 100 can be guaranteed even in a high-temperature and high-pressure combustion chamber.

[0059] In addition, compared with the prior art, the present application eliminates the premixing structure and instead opens an injection channel 133 on the inner wall of the main combustion stage. Therefore, the overall structure of the main combustion stage injection assembly 100 of the present application is simpler, the manufacturing cost is lower, and it has advantages such as a long service life.

[0060] It should be noted that the spacing between the injection port 1333 and the second inner portion 122 is consistent with the spacing between the injection port 1333 and the second outer portion 112, but due to issues such as the preparation process of each component, the injection port 1333 may not be accurately located at the center point between the second inner portion 122 and the second outer portion 112.

[0061] In some embodiments, reference Figure 1 、 Figure 2 and Figure 4 The injection channel 133 includes an injection hole 1332. The injection hole 1332 forms the above-mentioned injection port 1333 at the end of the second injection section 132 away from the first injection section 131. The axial direction of the injection hole 1332 is tilted relative to the axial direction of the main combustion stage fuel injection element 130. The injection angle of the injection port 1333 is designed to match the direction of the airflow in the main combustion stage channel 150. Specifically, the airflow flows from the channel opening 151 to the combustion chamber 222 and flows toward the main combustion stage flame zone. The direction of the airflow is outward diffusion. Since the injection angle of the injection port 1333 is designed to match the direction of the airflow in the main combustion stage channel 150, after the airflow is discharged from the channel opening 151, the movement direction of the airflow matches the movement direction of the fuel sprayed from the injection port 1333, and the fuel and the airflow can be better premixed in the combustion chamber 222. Therefore, even if the injection port 1333 is arranged close to the channel port 151, the injected fuel can be better premixed with the air flow in the combustion chamber 222 to ensure better combustion of the fuel in the main combustion stage flame zone.

[0062] In actual applications, the inclination angle of the injection hole 1332 can be designed according to the flow direction of the airflow from the channel opening 151 to the combustion chamber 222, so that the injection direction of the fuel matches the flow direction of the airflow, wherein the axial angle of the injection hole 1332 relative to the axial angle of the main combustion stage injection element 130 is set within the range of ±70 degrees.

[0063] In some embodiments, reference Figure 2 、 Figure 4 and Figure 5 The main combustion stage fuel injection component 130 is provided with an annular oil collecting groove 1331 around the central axis, and the rear end of the main combustion stage fuel injection component 130 is provided with an oil inlet 1334, that is, the first injection section 131 is away from the end of the second injection section 132, and the oil inlet 1334 is connected to the oil collecting groove 1331; at the same time, the front end of the second injection section 132 is provided with a plurality of injection holes 1332 at intervals around the central axis, that is, the second injection section 132 is away from the end of the first injection section 131, and one end of each injection hole 1332 is connected to the front end face of the oil collecting groove 1331, and each injection hole 1332 forms the above-mentioned injection port 1333 on the front end face of the second injection section 132; wherein, the oil collecting groove 1331 and each injection hole 1332 form the above-mentioned injection channel 133.

[0064] Specifically, the external fuel delivery assembly 400 supplies fuel into the annular oil collecting groove 1331 through the oil inlet 1334. The fuel in the oil collecting groove 1331 is simultaneously supplied to each injection hole 1332 and injected into the combustion chamber 222 through the injection port 1333 of the injection hole 1332. The arrangement of the oil collecting groove 1331 ensures that the fuel can flow smoothly along the axial direction of the main combustion stage injection element 130 with minimal resistance, thereby ensuring that the oil can be ejected from the injection port 1333 in an optimal manner. Furthermore, the arrangement of the multiple injection holes 1332 allows the fuel in the oil collecting groove 1331 to be ejected in a dispersed manner, thereby enabling rapid premixing of the fuel. Therefore, even if the injection hole 1333 is located relatively close to the channel opening 151, premixing of the fuel can still be ensured, thereby ensuring optimal combustion of the fuel in the main combustion stage flame zone.

[0065] Among them, the distance between the oil collecting groove 1331 and the first inner part 121 is consistent with the distance between the oil collecting groove 1331 and the first outer part 111, that is, the oil collecting groove 1331 is set at the center position of the main combustion stage channel 150, so as to ensure that the fuel can be better injected from the center position of the main combustion stage channel 150.

[0066] In addition, the oil collecting tank structure avoids the fuel from heating up too quickly and only uses a short spray hole at the end of the oil circuit. The overall thermal protection performance is excellent, which greatly reduces the risk of fuel coking and is suitable for application in high-temperature and high-pressure combustion chambers.

[0067] Furthermore, the axial direction of injection hole 1332 is tilted relative to the axial direction of oil collecting groove 1331. When the fuel in oil collecting groove 1331 is injected into the combustion chamber from injection hole 1332 at a certain angle, the direction of the fuel movement matches the direction of the airflow in the combustion chamber. Therefore, the fuel can be effectively premixed with the airflow before reaching the main combustion stage flame zone. In a specific implementation, the tilt angle of injection hole 1332 can be set according to the flow direction of the airflow in the main combustion stage channel 150 before entering the combustion chamber 222, so that the injection direction of the fuel matches the flow direction of the airflow, thereby achieving a better premixing effect.

[0068] The diameter of the injection hole 1332 is set between 0.1 mm and 1 mm. The size of the injection hole 1332 is small enough so that the fuel sprayed from the injection hole 1332 can be premixed with the airflow and atomized more quickly.

[0069] It should be noted that the injection channel 133 adopting the above-mentioned structural form has a better injection effect of the fuel. At the same time, the structure of the injection channel 133 is relatively simple, the processing difficulty is relatively low, the main combustion stage injection assembly 100 has a low manufacturing cost, and has extremely high application prospects.

[0070] Furthermore, the oil collecting groove 1331 divides the main stage fuel injector 130 into two side sections: an outer section 135 and an inner section 134. The outer section 135 is located outside the oil collecting groove 1331, while the inner section 134 is located inside the oil collecting groove 1331. The thickness of the inner section 134 and the outer section 135 are set to be consistent, ranging from 0.5 mm to 5 mm. The main stage fuel injector 130 adopting this structural form provides strong thermal protection for the outer section 135 and the inner section 134, effectively preventing the fuel in the oil collecting groove 1331 from coking and carbon deposits under high temperature conditions.

[0071] In one possible embodiment, referring to Figures 1 to 3 The main combustion stage fuel injection assembly 100 also includes a first annular sleeve 170, which is sleeved on the outer side of the first injection section 131 of the main combustion stage fuel injection component 130 and is located on the inner side of the first outer portion 111. A plurality of outer swirl blades 142 are spaced apart on the outer circumference of the first annular sleeve 170 and fixedly connected to the outer wall of the first annular sleeve 170. The outer edges of the outer swirl blades 142 are connected to the inner wall of the first outer portion 111. At the same time, a first boss 136 is provided on the outer circumference of the rear end of the first injection section 131, and the first boss 136 abuts against the rear end surface of the first annular sleeve 170. As can be seen from the above, when the main combustion stage fuel injection component 130 is assembled, the first annular sleeve 170 is used to position the main combustion stage fuel injection component 130, thereby facilitating the assembly of the main combustion stage fuel injection component 130.

[0072] In a possible embodiment, the main combustion stage fuel injection assembly 100 also includes a second annulus (not shown in the figure), and the first injection section 131 of the main combustion stage fuel injection member 130 is sleeved on the outside of the second annulus and located on the inside of the first inner portion 121. A plurality of outer swirl blades 142 are spaced apart on the inner circumference of the first annulus 170 and fixedly connected to the inner wall of the second annulus, and the outer edge of the outer swirl blades 142 is connected to the inner wall of the first outer portion 111. At the same time, the inner circumference of the rear end portion of the first injection section 131 is provided with a second boss (not shown in the figure), and the second boss is supported on the rear end face of the second annulus. As can be seen from the above, when the main combustion stage fuel injection member 130 is assembled, the second annulus is used to position the main combustion stage fuel injection member 130, thereby facilitating the assembly of the main combustion stage fuel injection member 130.

[0073] In some embodiments, the main combustion stage channel 150 includes at least a contraction section 152, a connection portion 154 and an expansion section 153. The connection portion 154 is connected between the contraction section 152 and the expansion section 153. The airflow entering the main combustion stage channel 150 passes through the contraction section 152, the connection portion 154 and the expansion section 153 in sequence. Therefore, the contraction section 152 is connected to the rear side of the connection portion 154, and the expansion section 153 is connected to the front side of the expansion section 153. The end of the expansion section 153 away from the connection portion 154 is the above-mentioned channel opening 151; wherein, along the axial direction toward the channel opening 151 of the main combustion stage channel 150, that is, the axial flow direction of the airflow in the main combustion stage channel 150, the inner diameter of the contraction section 152 gradually decreases, and the inner diameter of the expansion section 153 gradually increases.

[0074] Among them, the inner diameter of the contraction section 152 gradually decreases, and the rate of change of the inner diameter of the contraction section 152 can be partially the same or partially different, but it can be considered that the inner diameter gradually decreases. Similarly, the inner diameter of the expansion section 153 gradually increases, and the rate of change of the inner diameter of the expansion section 153 can be partially the same or partially different, but it can be considered that the inner diameter gradually increases. In addition, the connection portion 154 can be a connection node between the expansion section 153 and the contraction section 152. In other words, the intersection formed by the expansion section 153 and the contraction section 152 is the above-mentioned connection portion 154. Alternatively, the connection portion 154 has a certain length in the axial direction of the main combustion stage injection component 130, the contraction section 152 is connected to the rear end of the connection portion 154, and the expansion section 153 is connected to the front end of the connection portion 154.

[0075] In actual applications, while ensuring the safety of the main combustion stage fuel injection assembly 100, the injection port 1333 can be located inside one of the contraction section 152, the connection section 154, and the expansion section 153. For example, when the temperature and pressure of the combustion chamber 222 are too high, the injection port 1333 is located inside the connection section 154 or the expansion section 153 to reduce the risk of spontaneous combustion or flashback in the main combustion stage channel 150. When the temperature and pressure of the combustion chamber 222 are relatively low, the injection port 1333 is located inside the connection section 154 or the contraction section to ensure the premixing effect of the fuel.

[0076] Specifically, the airflow from outer swirl blades 142 and inner swirl blades 141 converge at connection portion 154, accelerating the airflow and effectively enhancing fuel atomization and premixing, ensuring more uniform combustion and a faster combustion rate. Furthermore, the provision of expansion section 153 diffuses the airflow passing through connection portion 154 as it passes through expansion section 153, ensuring that the airflow diffuses and flows upon entering combustion chamber 222, facilitating sufficient combustion of the fuel.

[0077] Furthermore, the main combustion stage fuel injection assembly 100 also includes an intermediate connector 160, which is connected to the end of the main combustion stage inner wall 120 near the channel opening 151. The inner side of the intermediate connector 160 can be used to connect to the pre-combustion stage fuel injection assembly 300. The intermediate connector 160 defines a cooling channel 161. One section of the cooling channel 161 extends along the axial direction of the intermediate connector 160 and passes through the rear end of the intermediate connector 160. The other end extends along the radial direction of the intermediate connector 160 to the inner circumferential surface of the intermediate connector 160 and communicates with the connecting portion 154.

[0078] Among them, through the setting of the intermediate connecting member 160, the intermediate connecting member 160 facilitates the installation of the pre-combustion stage injection assembly 300 at the center position of the main combustion stage injection assembly 100; and, through the setting of the cooling channel 161, the airflow passing through the cooling channel 161 can be used to cool the front end of the intermediate connecting member 160; and, the cooling channel 161 is connected to the connecting part 154, and the airflow entering the main combustion stage channel 150 from the cooling channel 161 is converged and accelerated with other airflows to enhance the premixing effect of the fuel.

[0079] The present invention also discloses a staged combustion chamber 30 with downstream injection of the main combustion stage, referring to Figure 6The staged combustion chamber 30 includes a housing assembly 200, the main combustion stage fuel injection assembly 100, the pre-combustion stage fuel injection assembly 300, a fuel delivery assembly 400 and a diffuser 500. The housing assembly 200 includes a combustion chamber outer casing 210 and a combustion chamber inner casing 220. The combustion chamber inner casing 220 is arranged on the inner side of the combustion chamber outer casing 210. The inner side of the combustion chamber inner casing 220 forms a combustion chamber 222. The side wall of the combustion chamber inner casing 220 is provided with a hole connected to the combustion chamber 222. 2; the main combustion stage injection assembly 100 is arranged at the air inlet of the outer casing 220 of the combustion chamber; the pre-combustion stage injection assembly 300 is connected to the inner side of the intermediate connecting piece 160 of the main combustion stage injection assembly 100 and is coaxially arranged; the fuel delivery assembly 400 is arranged in the outer casing 210 of the combustion chamber, and is used to deliver fuel to the main combustion stage injection assembly 100 and to the pre-combustion stage injection assembly 300; the diffuser 500 is arranged at the air inlet of the outer casing 210 of the combustion chamber.

[0080] Specifically, the air enters the inner side of the combustion chamber casing 210 after being decelerated and diffused by the diffuser 500. The air flow entering the combustion chamber casing 210 is divided into multiple flow directions, among which a part of the air flow flows to the main combustion stage fuel injection assembly 100, and enters the combustion chamber 222 of the combustion chamber casing 220 through the main combustion stage fuel injection assembly 100; a part of the air flow flows to the pre-combustion stage fuel injection assembly 300, and enters the combustion chamber 222 of the combustion chamber casing 220 through the pre-combustion stage fuel injection assembly 300; a part of the air flow flows through the gap between the combustion chamber casing 210 and the combustion chamber casing 220 to the vent 221, and enters the combustion chamber 222 through the vent. At the same time, the fuel delivery component 400 delivers a small amount of fuel to the pre-combustion stage injection component 300, and injects it into the pre-combustion stage flame zone of the combustion chamber 222 through the pre-combustion stage injection component 300, and the fuel burns in the pre-combustion stage flame zone; the fuel delivery component 400 delivers most of the fuel to the main combustion stage injection component 100, and injects it into the main combustion stage flame zone of the combustion chamber 222 through the main combustion stage injection component 100, and the fuel burns in the main combustion stage flame zone.

[0081] The present invention also discloses an aero-engine, referring to Figure 7 , including a low-pressure compressor 10, a high-pressure compressor 20, a staged combustion chamber 30, a high-pressure turbine 40 and a low-pressure turbine 50. The air inlet of the high-pressure compressor 20 is connected to the air outlet of the low-pressure compressor 10; the air inlet of the staged combustion chamber 30 is connected to the air outlet of the high-pressure compressor 20; the air inlet of the high-pressure turbine 40 is connected to the air outlet of the staged combustion chamber 30; and the air inlet of the low-pressure turbine 50 is connected to the air outlet of the high-pressure turbine 40.

[0082] Specifically, when the engine is working, the air is compressed by the low-pressure compressor 10 and then enters the high-pressure compressor 20. The high-pressure air burns with the fuel in the staged combustion chamber 30. The high-temperature and high-pressure combustion gas formed after combustion enters the high-pressure turbine 40 and the low-pressure turbine 50, and the driving is completed by the turbine doing work.

[0083] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A main combustion stage fuel injection assembly, comprising a main combustion stage outer wall, a main combustion stage inner wall and a main combustion stage fuel injection element, wherein: The outer wall of the main combustion stage is arranged in an annular shape, and the outer wall of the main combustion stage includes at least a first outer portion and a second outer portion connected to each other in the longitudinal direction; The main combustion stage inner wall is annularly arranged, and the main combustion stage outer wall includes at least a first inner portion and a second inner portion connected to each other in the longitudinal direction. The main combustion stage inner wall is spaced apart and coaxially arranged on the inner side of the main combustion stage outer wall; wherein a swirl channel is formed between the first inner portion and the first outer portion, and a main combustion stage channel is formed between the second inner portion and the second outer portion, and a port of the main combustion stage channel away from the swirl channel is a channel port for communicating with the combustion chamber; The main combustion stage fuel injection member is arranged in an annular shape, and the main combustion stage fuel injection member is spaced and arranged between the main combustion stage outer wall and the main combustion stage inner wall, and is arranged coaxially. The main combustion stage fuel injection member includes at least a first injection section and a second injection section connected in the longitudinal direction, the first injection section is located in the swirl channel, an outer swirl blade is provided between the first injection section and the first outer portion, an inner swirl blade is provided between the first injection section and the first inner portion, and the second injection section is located in the main combustion stage channel; wherein the main combustion stage fuel injection member is provided with a spray channel, the spray channel forming a fuel inlet in the first spray section, the spray channel forming a spray port in the second spray section at an end away from the first spray section, the spacing between the spray port and the first inner portion is consistent with the spacing between the spray port and the first outer portion, and the spray port is arranged toward the channel opening, so that the main combustion stage fuel injection member can spray fuel into the combustion chamber through the channel opening; The injection channel includes an oil collecting groove, the main combustion stage fuel injection member is provided with an annular oil collecting groove around the central axis, the distance between the oil collecting groove and the first inner portion is consistent with the distance between the oil collecting groove and the first outer portion, and the rear end portion of the main combustion stage fuel injection member is provided with an oil inlet, and the oil inlet is connected to the oil collecting groove; The main combustion stage fuel injection assembly further includes a first annular sleeve, the first annular sleeve is arranged on the outer side of the main combustion stage fuel injection component, the outer swirl blade is arranged between the first annular sleeve and the first outer portion, and a first boss is provided on the circumference of the main combustion stage fuel injection component, the first boss abuts against an end of the first annular sleeve away from the main combustion stage channel; And / or, the main combustion stage fuel injection assembly also includes a second ring sleeve, the main combustion stage fuel injection part is sleeved on the outside of the second ring sleeve, the inner swirl blade is arranged between the second ring sleeve and the first inner part, and the circumferential surface of the main combustion stage fuel injection part is provided with a second boss, and the second boss is supported on the end of the second ring sleeve away from the main combustion stage channel.

2. The main combustion stage fuel injection assembly according to claim 1, characterized in that: The injection channel includes an injection hole, which forms the injection port at the end of the second injection section. The axial direction of the injection hole is inclined relative to the axial direction of the main combustion stage injection component so that the injection angle of the injection port matches the airflow direction in the main combustion stage channel.

3. The main combustion stage fuel injection assembly according to claim 1, characterized in that: The injection channel also includes a plurality of injection holes; the second injection section is provided with a plurality of the injection holes spaced apart around the central axis, each of the injection holes is connected to the oil collecting tank near the channel mouth, and the injection port is formed at the end of the second injection section, and the diameter of the injection hole is set between 0.1 mm and 1 mm.

4. The main combustion stage fuel injection assembly according to claim 3, characterized in that: The main combustion stage fuel injection component has an inner portion and an outer portion, and the oil collecting groove is formed between the inner portion and the outer portion; wherein the thickness of the inner portion is consistent with the thickness of the outer portion and is between 0.5 mm and 5 mm.

5. The main combustion stage fuel injection assembly according to claim 1, characterized in that: The distance between the injection port and the channel port is set between 0 mm and 100 mm.

6. The main combustion stage fuel injection assembly according to claim 1, characterized in that: The main combustion stage channel includes at least a contraction section, a connecting portion and an expansion section for the air flow to pass through in sequence, and the connecting portion is arranged between the contraction section and the expansion section, wherein the main combustion stage channel is along the axial direction toward the channel opening, the inner diameter of the contraction section gradually decreases, and the inner diameter of the expansion section gradually increases, and the injection port is located on the inner side of one of the contraction section, the connecting portion and the expansion section.

7. The main combustion stage fuel injection assembly according to claim 6, characterized in that: The main combustion stage fuel injection assembly also includes an intermediate connecting piece for connecting the pre-combustion stage fuel injection assembly, the intermediate connecting piece is connected to the end of the inner wall of the main combustion stage close to the channel mouth, the intermediate connecting piece is provided with a cooling channel, one end of the cooling channel is connected to at least the connecting part, and the other end is connected to the end of the intermediate connecting piece away from the combustion chamber.

8. A staged combustion chamber with downstream injection of the main combustion stage, characterized in that: include: A housing assembly, the housing assembly comprising a combustion chamber outer housing and a combustion chamber inner housing, the combustion chamber inner housing being disposed inside the combustion chamber outer housing, the combustion chamber inner housing inner housing having a vent hole communicating with the combustion chamber; The main combustion stage fuel injection assembly according to any one of claims 1 to 7, wherein the main combustion stage fuel injection assembly is arranged at the air inlet of the inner casing of the combustion chamber; A pre-combustion stage fuel injection assembly, the pre-combustion stage fuel injection assembly being arranged inside the main combustion stage fuel injection assembly and being coaxially arranged; A fuel delivery assembly, the fuel delivery assembly being arranged in the outer casing of the combustion chamber and being used for delivering fuel to the main combustion stage fuel injection assembly and to the pre-combustion stage fuel injection assembly; A diffuser is provided at the air inlet of the outer casing of the combustion chamber.

9. An aircraft engine, characterized in that: include: low-pressure compressor; a high-pressure compressor, wherein an air inlet of the high-pressure compressor is connected to an air outlet of the low-pressure compressor; The staged combustion chamber according to claim 8, wherein the air inlet of the staged combustion chamber is connected to the air outlet of the high-pressure compressor; a high-pressure turbine, wherein an air inlet of the high-pressure turbine is connected to an air outlet of the staged combustion chamber; A low-pressure turbine, wherein the air inlet of the low-pressure turbine is connected to the air outlet of the high-pressure turbine.

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