Dual-fuel center staged multi-flame combustion chamber

Abstract

The invention relates to the technical field of combustion chambers, and provides a dual-fuel center staged multi-flame combustion chamber which comprises a combustion chamber body, a pre-combustion stage device, a first main combustion stage device and a second main combustion stage device, and the pre-combustion stage device, the first main combustion stage device and the second main combustion stage device are arranged at the front end of the combustion chamber body; the pre-combustion stage device comprises a pre-combustion stage assembly and a pre-combustion mixing chamber, the pre-combustion mixing chamber communicates with the combustion chamber body, a first channel and a second channel are arranged in the pre-combustion stage assembly, the first channel communicates with the pre-combustion mixing chamber, the first channel, the pre-combustion mixing chamber and the combustion chamber body are coaxially arranged, and first fuel enters the pre-combustion mixing chamber through the first channel; the pre-combustion mixing chamber is arranged on the periphery of the second channel, the second channel communicates with the pre-combustion mixing chamber, and second fuel enters the pre-combustion mixing chamber through the second channel; a third channel is arranged in the first main combustion stage device, a fourth channel is arranged in the second main combustion stage device, the fourth channel is communicated with the third channel, and the third channel is communicated with the combustion chamber body.

Description

Technical Field

[0001] The invention relates to the technical field of combustion chambers, and in particular to a dual-fuel central staged multi-flame combustion chamber. Background Art

[0002] In aircraft power systems, the design of the combustion chamber is one of the key technologies. Among them, the center-staged multi-flame combustion chamber, with its flexible nozzle grading method, has shown significant advantages in broadening the stable operating range of the combustion chamber, reducing local oil-rich areas, and reducing the amount of soot generated. Through the graded design of the nozzles, the combustion chamber can achieve a stable combustion state according to different working conditions, thereby effectively improving the combustion efficiency and combustion uniformity. Furthermore, by accurately adjusting the nozzle position, the temperature distribution at the combustion chamber outlet can also be finely adjusted to meet the engine's strict requirements for temperature uniformity.

[0003] However, despite the excellent performance of the center-staged multi-flame combustion chamber in many aspects, its problems such as uneven fuel distribution and incomplete combustion are still prominent under high load and high speed conditions. These problems not only limit the performance of the combustion chamber, but may also lead to a decrease in the overall efficiency and stability of the engine, thereby affecting the overall performance of the aircraft. Especially under high flow conditions, kerosene has poor ignition and self-stabilization performance when used as fuel, which further exacerbates the problem of incomplete combustion.

[0004] Pure hydrogen combustion chambers, such as hydrogen diffusion combustion chambers and hydrogen micro-mixing combustion chambers, have shown unique advantages in high-temperature and high-efficiency combustion. However, under high-flow conditions, the combustion process of hydrogen can easily cause thermoacoustic oscillations, resulting in unstable combustion, which seriously affects the performance and safety of the combustion chamber.

[0005] In order to overcome the shortcomings of single fuel, mixed fuel combustion chambers came into being. Among them, the dual-fuel combustion system of liquefied natural gas (LNG) and aviation kerosene is a typical representative. By mixing LNG and aviation kerosene, this system can solve the shortcomings of single fuel in combustion performance, economy or environmental protection to a certain extent. However, the combustion process of mixed fuels is more complicated than that of single fuels. Especially in the case of mixing multiple fuels, how to achieve uniform mixing and stable combustion of fuels has become a major problem in the design of mixed fuel combustion chambers. Summary of the invention

[0006] The invention provides a dual-fuel center-staged multi-flame combustion chamber, which is used to solve the problem of unstable combustion of the dual-fuel center-staged multi-flame combustion chamber in the prior art.

[0007] The present invention provides a dual-fuel center-staged multi-flame combustion chamber, comprising: a combustion chamber body, a pre-combustion stage device, a first main combustion stage device and a second main combustion stage device, wherein the pre-combustion stage device, the first main combustion stage device and the second main combustion stage device are respectively arranged at the front end of the combustion chamber body; the pre-combustion stage device comprises a pre-combustion stage assembly and a pre-combustion mixing chamber, the pre-combustion mixing chamber is connected to the combustion chamber body, a first channel and a second channel are arranged in the pre-combustion stage assembly, the first channel is connected to the pre-combustion mixing chamber, the first channel, the pre-combustion mixing chamber and the combustion chamber body are coaxially arranged, and a first fuel enters the pre-combustion mixing chamber through the first channel; the pre-combustion mixing chamber is arranged at the periphery of the second channel, the second channel is connected to the pre-combustion mixing chamber, and the second fuel enters the pre-combustion mixing chamber through the second channel; a third channel is arranged in the first main combustion stage device, and a fourth channel is arranged in the second main combustion stage device, the fourth channel is connected to the third channel, and the third channel is connected to the combustion chamber body; the first fuel enters the combustion chamber body through the third channel, and the second fuel enters the combustion chamber body through the fourth channel and the third channel.

[0008] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, there are a plurality of first main combustion stage devices, and the plurality of first main combustion stage devices are arranged around the periphery of the pre-combustion stage device.

[0009] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the pre-combustion stage assembly includes a first nozzle, a second nozzle, an annular air collecting chamber, a first swirler and a first venturi, the annular air collecting chamber is arranged at the front end of the pre-combustion mixing chamber, the first swirler is arranged on the side of the annular air collecting chamber away from the pre-combustion mixing chamber, the first swirler and the annular air collecting chamber form the first channel; the first nozzle is connected to the inlet of the first channel; the blades of the first swirler form a first tangential inlet, and air enters the first channel through the first tangential inlet; the first venturi is arranged between the annular air collecting chamber and the pre-combustion mixing chamber, the second nozzle is connected to the inlet of the annular air collecting chamber, a plurality of flow channels are arranged in the side wall of the first venturi, the inlet of each of the flow channels is connected to the outlet of the annular air collecting chamber, and the outlet of each of the flow channels is arranged toward the pre-combustion mixing chamber.

[0010] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the pre-combustion stage assembly includes a second swirler, the second swirler is arranged between the annular air collecting chamber and the pre-combustion mixing chamber, the blades of the second swirler form a second tangential inlet, and air enters the pre-combustion mixing chamber through the gap between the inner wall of the second swirler and the outer wall of the first venturi tube.

[0011] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the first main combustion stage device includes a third nozzle and a mixing tube, the third channel is arranged in the mixing tube, the third nozzle is connected to the third channel, and the front end of the mixing tube is provided with a third tangential inlet.

[0012] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the first main combustion stage device also includes a sleeve, which is arranged in the mixing tube, the inlet of the sleeve is connected to the third tangential inlet and the third nozzle respectively, and the outlet of the sleeve is connected to the outlet of the mixing tube; the cross-sectional area of ​​the sleeve gradually decreases along the direction from the inlet of the sleeve toward the outlet of the sleeve.

[0013] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the outer wall of the mixing tube is also provided with a plurality of first openings, and the plurality of first openings are arranged at intervals along the circumference of the mixing tube and are located between the outlet of the sleeve and the outlet of the mixing tube.

[0014] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the first main combustion stage device also includes a second venturi tube, the second venturi tube is arranged in the mixing tube, the inlet of the second venturi tube is connected to the outlet of the sleeve, and the outlet of the second venturi tube is connected to the outlet of the mixing tube.

[0015] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the outer wall of the mixing tube is further provided with a plurality of second openings, the plurality of second openings are arranged at intervals along the circumference of the mixing tube, and the second openings are arranged close to the outlet of the second venturi tube.

[0016] According to a dual-fuel center-staged multi-flame combustion chamber provided by the present invention, the second main combustion stage device includes a fourth nozzle and an air collecting box, the air collecting box is arranged between the pre-combustion mixing chamber and the combustion chamber body, the fourth nozzle is connected to the inlet of the air collecting box, and the outlet of the air collecting box is connected to the third channel.

[0017] The dual-fuel center-staged multi-flame combustion chamber provided by the present invention is provided with a first channel and a second channel in the pre-combustion stage device, so that the first fuel can enter the pre-combustion mixing chamber through the first channel, and the second fuel can enter the pre-combustion mixing chamber through the second channel, and then enter the center of the combustion chamber body; the first fuel is input to the circumference of the combustion chamber body by setting a first main combustion stage device; the second fuel is input to the circumference of the combustion chamber body by setting a second main combustion stage device, so that the first fuel or the second fuel is evenly distributed in the combustion chamber. In the actual combustion process, different fuels can be switched for combustion according to demand, the combustion is stable, and the emission level in the combustion chamber is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of a dual-fuel central staged multi-flame combustion chamber provided by the present invention; Figure 2 This is a front view of the dual-fuel center-staged multi-flame combustion chamber provided by the present invention; Figure 3 is a cross-sectional view of a dual-fuel central staged multi-flame combustion chamber provided by the present invention; Figure 4 It is a structural schematic diagram of the pre-combustion stage device provided by the present invention; Figure 5 is a cross-sectional view of a first main combustion stage device provided by the present invention; Figure 6 is a schematic end view of a first venturi tube provided by the present invention; Reference numerals: 100. Combustion chamber body; 200, pre-combustion stage device; 210, pre-combustion stage assembly; 211, first nozzle; 212, second nozzle; 213, annular gas collecting chamber; 214, first swirler; 2141, first tangential inlet; 215, second swirler; 2151, second tangential inlet; 216, first venturi; 2161, flow channel; 21611, outlet of flow channel; 220, pre-combustion mixing chamber; 230, first channel; 240, second channel; 300, first main combustion stage device; 310, third nozzle; 320, mixing tube; 321, third tangential inlet; 322, first opening; 323, second opening; 324, through hole; 330, sleeve; 340, second venturi tube; 350, third channel; 400. Second main combustion stage device; 410. Fourth nozzle; 420. Gas collecting box; 430. Fourth channel. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0024] Embodiments of the present invention are described in detail below, examples of which 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 to be used to explain the present invention, and should not be construed as limiting the present invention.

[0025] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0026] Combine the following Figure 1-Figure 6 The dual fuel center staged multi-flame combustor of the present invention is described.

[0027] The dual-fuel center-staged multi-flame combustion chamber provided in an embodiment of the present invention comprises a combustion chamber body 100, a pre-combustion stage device 200, a first main combustion stage device 300 and a second main combustion stage device 400. The pre-combustion stage device 200, the first main combustion stage device 300 and the second main combustion stage device 400 are respectively arranged at the front end of the combustion chamber body 100, and the fuel enters the combustion chamber body 100 for combustion after passing through at least one of the pre-combustion stage device 200, the first main combustion stage device 300 and the second main combustion stage device 400.

[0028] The pre-combustion stage device 200 includes a pre-combustion stage assembly 210 and a pre-combustion mixing chamber 220, and the pre-combustion mixing chamber 220 is connected to the combustion chamber body 100. A first channel 230 and a second channel 240 are provided in the pre-combustion stage assembly 210, and the first channel 230 is connected to the pre-combustion mixing chamber 220, and the first channel 230, the pre-combustion mixing chamber 220 and the combustion chamber body 100 are coaxially arranged. The first fuel enters the pre-combustion mixing chamber 220 after being mixed with air through the first channel 230, and then enters the center of the combustion chamber body 100 for combustion after mixing. The first fuel includes kerosene. The pre-combustion mixing chamber 220 is arranged at the periphery of the second channel 240, and the second channel 240 is connected to the pre-combustion mixing chamber 220, and the second fuel enters the pre-combustion mixing chamber 220 through the second channel 240, and is fully mixed with air in the pre-combustion mixing chamber 220, and then enters the combustion chamber body 100 for combustion after mixing. The second fuel includes hydrogen. It is understandable that the first channel 230 and the second channel 240 are provided with air inlets, so that air can enter the first channel 230 and the second channel 240 to mix with the fuel. In one embodiment, kerosene enters the pre-combustion mixing chamber 220 through the first channel 230, and hydrogen enters the pre-combustion mixing chamber 220 through the second channel 240. The kerosene and hydrogen are mixed in the pre-combustion mixing chamber 220, and then enter the combustion chamber body 100 for combustion.

[0029] A third channel 350 is provided in the first main combustion stage device 300, and the third channel 350 is connected to the combustion chamber body 100, and the first fuel (kerosene) enters the combustion chamber body 100 through the third channel 350 for combustion. A fourth channel 430 is provided in the second main combustion stage device 400, and the fourth channel 430 is connected to the third channel 350, and the second fuel (hydrogen) enters the combustion chamber body 100 through the fourth channel 430 and the third channel 350. When the first fuel and the second fuel are input at the same time, the first fuel and the second fuel can be mixed at the outlet of the third channel 350, and then enter the combustion chamber body 100 after mixing. It can be understood that the third channel 350 is also provided with an air inlet, and air enters the third channel 350 to be mixed with the fuel.

[0030] The dual-fuel center-staged multi-flame combustion chamber provided by the embodiment of the present invention is provided with a first channel 230 and a second channel 240 in the pre-combustion stage device 200, so that the first fuel can enter the pre-combustion mixing chamber through the first channel 230, and the second fuel can enter the pre-combustion mixing chamber through the second channel 240, and then enter the center of the combustion chamber body 100; the first main combustion stage device 300 is provided to input the first fuel to the circumference of the combustion chamber body 100; the second main combustion stage device 400 is provided to input the second fuel to the circumference of the combustion chamber body 100, so that the first fuel or the second fuel is evenly distributed in the combustion chamber. In the actual combustion process, different fuels can be switched for combustion according to demand, the combustion is stable, and the emission level in the combustion chamber is reduced.

[0031] In the embodiment of the present invention, there are multiple first main combustion stage devices 300, and the multiple first main combustion stage devices 300 are arranged around the outer periphery of the pre-combustion stage device 200, so that the fuel is evenly distributed in the combustion chamber body 100 and burns fully, thereby improving the combustion efficiency. Each first main combustion stage device 300 is provided with an independent channel, which can adjust the fuel supply according to the combustion demand in the combustion chamber, and can realize accurate control and optimal distribution of fuel under different combustion conditions, so as to achieve efficient and stable combustion effect. The number of first main combustion stage devices 300 can be 3, 5, 7, 8, 10, etc. Figure 1 and Figure 2 As shown, there are seven first main combustion stage devices 300.

[0032] like Figure 3 and Figure 4 As shown, the pre-combustion stage assembly 210 includes a first nozzle 211, a second nozzle 212, an annular air collecting chamber 213, a first swirler 214 and a first venturi 216. The annular air collecting chamber 213 is arranged at the front end of the pre-combustion mixing chamber 220. The first swirler 214 is arranged on the side of the annular air collecting chamber 213 away from the pre-combustion mixing chamber 220, and the first swirler 214 and the inner wall of the annular air collecting chamber 213 form a first channel 230. The first nozzle 211 is connected to the inlet of the first channel 230, and the first nozzle 211 includes a pressure atomizing nozzle. The first fuel (kerosene) enters the first channel 230 through the first nozzle 211, and enters the pre-combustion mixing chamber 220 after being mixed with air. Specifically, the blades of the first swirler 214 form a first tangential inlet 2141, and air can enter the first swirler 214 through the first tangential inlet 2141 and mix with the first fuel (kerosene), that is, enter the first channel 230 to mix with the first fuel (kerosene), and then enter the pre-combustion mixing chamber 220 after mixing. The first tangential inlet 2141 generates a swirl in the first swirler 214, and can be fully mixed with the first fuel (kerosene). The embodiment of the present invention optimizes the contact between air and fuel through the design of the first swirler 214, ensures sufficient atomization and mixing of the fuel, and improves the efficiency of pre-combustion.

[0033] The second nozzle 212 is connected to the inlet of the annular air collecting chamber 213, and the outlet of the annular air collecting chamber 213 is connected to the pre-combustion mixing chamber 220 via the first venturi 216. Specifically, the first venturi 216 is arranged between the annular air collecting chamber 213 and the pre-combustion mixing chamber 220. The first venturi 216 accelerates the speed of the air flow passing through and reduces the pressure, thereby forming a flow regulation effect and further enhancing the mixing efficiency. In addition, the first venturi 216 can also further atomize the first fuel (kerosene) to improve the atomization effect. The side wall of the first venturi 216 is provided with a flow channel 2161, and the inlet of the flow channel 2161 is connected to the outlet of the annular air collecting chamber 213. The end of the first venturi 216 is provided with a jet nozzle (such as a micro hole with a diameter of 0.3 mm), such as Figure 6 As shown, the injection port is the outlet 21611 of the flow channel, and the second fuel (hydrogen) enters the annular gas collecting chamber 213, flows to the end of the first venturi 216 through the flow channel on the side wall of the first venturi 216, and is injected toward the pre-combustion mixing chamber 220 through the outlet 21611 of the flow channel.

[0034] The side wall of the first venturi tube 216 is provided with a plurality of flow channels 2161 (the end of the first venturi tube 216 is provided with a plurality of injection ports, such as 30), and the plurality of flow channels 2161 are arranged at intervals along the circumference of the first venturi tube 216, and the outlet 21611 of the flow channel is located at the periphery of the outlet of the first channel 230, so that the second fuel (hydrogen) can be uniformly injected into the pre-combustion mixing chamber 220, further improving the mixing effect, and effectively suppressing the combustion thermoacoustic instability of the second fuel (hydrogen). The second nozzle 212 includes a straight-injection nozzle.

[0035] Furthermore, the pre-combustion stage assembly 210 further includes a second swirler 215, which is disposed between the annular air collecting chamber 213 and the pre-combustion mixing chamber 220, and is located on the outer periphery of the first venturi 216. The blades of the second swirler 215 form a second tangential inlet 2151, and air can enter the second swirler 215 through the second tangential inlet 2151, and enter the air flow channel formed by the inner wall of the second swirler 215 and the outer wall of the first venturi 216, and then enter the pre-combustion mixing chamber 220 after mixing with the second fuel (hydrogen) ejected from the end of the first venturi 216. In the case where the second fuel is not introduced into the second channel 240, the air can be mixed with the first fuel (kerosene) at the outlet of the second channel 240, and then enter the pre-combustion mixing chamber 220 after mixing. The second tangential inlet 2151 generates a swirl in the second swirler 215, and can be fully mixed with the fuel at the outlet of the second channel 240.

[0036] The embodiment of the present invention can improve the mixing effect of air and the first fuel (kerosene) by providing the first swirler 214; and can improve the mixing effect of air and the second fuel (hydrogen) or the first fuel (kerosene) by providing the second swirler 215, so that the first fuel (kerosene) and the second fuel (hydrogen) enter the combustion chamber body 100 in a lean state for combustion, and the combustion is stable. By providing the first venturi 216, the atomization effect of the first fuel (kerosene) can be improved. In addition, the combustion chamber can switch to the second fuel (hydrogen) when the first fuel (kerosene) is burning. When the second fuel (hydrogen) is burning stably, it is switched to the first fuel (kerosene) for combustion.

[0037] The first main combustion stage device 300 includes a third nozzle 310 and a mixing tube 320. The third channel 350 is arranged in the mixing tube 320, and the third nozzle 310 is connected to the third channel 350. The front end of the mixing tube 320 is provided with a third tangential inlet 321, such as a tangential circular hole, a tangential square hole, etc., and air can enter the mixing tube 320 through the third tangential inlet 321 to generate a swirl, that is, enter the third channel 350, and be fully mixed with the first fuel in the third channel 350. There are multiple third tangential inlets 321, and the multiple third tangential inlets 321 are arranged at intervals along the circumference of the mixing tube 320 to increase the amount of air entering and improve the mixing effect of air and the first fuel (kerosene). The third nozzle 310 is a straight nozzle.

[0038] like Figure 3 and Figure 5 As shown, the first main combustion stage device 300 also includes a sleeve 330, which is arranged in the mixing tube 320, and the inlet of the sleeve 330 is connected to the third tangential inlet 321, and air can enter the sleeve 330 through the third tangential inlet 321 to generate a swirl; the inlet of the sleeve 330 is also connected to the third nozzle 310, and the first fuel (kerosene) enters the sleeve through the third nozzle 310; the outlet of the sleeve 330 is connected to the outlet of the mixing tube 320, and the cross-sectional area of ​​the sleeve 330 gradually decreases along the direction from the inlet of the sleeve 330 toward the outlet of the sleeve 330, and the flow rate of the fluid passing through the sleeve 330 gradually increases. The first fuel (kerosene) enters the sleeve 330 through the third nozzle 310, and after being mixed with the air entering from the third tangential inlet 321, forms a film on the inner wall surface of the sleeve 330. As the flow rate increases, it is broken at the end of the sleeve 330 and atomized, and after atomization, it enters the combustion chamber body 100 through the outlet of the mixing tube 320. The third tangential inlet 321 generates a swirl in the sleeve 330, which can be fully mixed with the first fuel (kerosene).

[0039] The outer wall of the mixing tube 320 is provided with a first opening 322, and the first opening 322 is located between the outlet of the sleeve 330 and the outlet of the mixing tube 320. Air can enter the mixing tube 320 through the first opening 322 and mix with the atomized first fuel (kerosene) at the end of the sleeve 330. There are multiple first openings 322, and the multiple first openings 322 are arranged at intervals along the circumference of the mixing tube 320 to further improve the mixing effect. The amount of air entering increases, so that the first fuel (kerosene) in the mixing tube 320 is sprayed into the combustion chamber body 100 in a lean state, which reduces the temperature of the main combustion zone and reduces the emission of NOx.

[0040] Furthermore, the first main combustion stage device 300 further includes a second venturi tube 340, which is disposed in the mixing tube 320, and the inlet of the second venturi tube 340 is connected to the outlet of the sleeve 330, such as Figure 5 As shown, the first opening 322 is located between the outlet of the sleeve 330 and the inlet of the second venturi 340; the outlet of the second venturi 340 is connected to the outlet of the mixing tube 320. The first fuel (kerosene) enters the sleeve 330 through the third nozzle 310, and after being mixed with the air entering from the third tangential inlet 321, a film is formed on the inner wall surface of the sleeve 330. As the flow rate increases, it is broken at the end of the sleeve 330 to achieve the first atomization. The atomized first fuel (kerosene) is mixed with the air entering from the first opening 322, and after mixing, it enters the second venturi 340, and a film is formed again on the inner wall surface of the second venturi 340. As the structure of the second venturi 340 changes, the flow rate also changes, and it is broken at the end of the second venturi 340 to achieve the second atomization. The first fuel (kerosene) after the second atomization enters the combustion chamber body 100, and the atomization effect is good, which helps to improve the stability of combustion.

[0041] The outer wall of the mixing tube 320 is also provided with a second opening 323, which is arranged near the outlet of the second venturi 340. The air enters the air flow channel between the inner wall of the mixing tube 320 and the outer wall of the second venturi 340 through the second opening 323, flows toward the outlet of the mixing tube 320, and mixes again with the first fuel (fuel oil) at the end of the second venturi 340 at the end of the mixing tube 320. There are multiple second openings 323, and the multiple second openings 323 are arranged at intervals along the circumference of the mixing tube 320 to further improve the mixing effect; the amount of air entering is increased, and the first fuel (kerosene) entering is sprayed into the combustion chamber body 100 in a lean state, which reduces the temperature of the main combustion zone and reduces the emission of NOx.

[0042] The first opening 322 in the embodiment of the present invention may be circular, elliptical, or polygonal. Figure 1 and Figure 5As shown, the first opening 322 is a rectangular opening. The second opening 323 in the embodiment of the present invention can be circular, elliptical, or polygonal. Figure 1 and Figure 5 As shown, the second opening 323 is a rectangular opening.

[0043] The second main combustion stage device 400 includes a fourth nozzle 410 and an air collecting box 420, and the air collecting box 420 is arranged between the pre-combustion mixing chamber 220 and the combustion chamber body 100. It should be noted that a plurality of avoidance openings are arranged on the air collecting box 420, and each first main combustion stage device 300 can be connected to the combustion chamber body 100 through an avoidance hole; that is, each mixing tube 320 is inserted into the avoidance hole. The fourth nozzle 410 is connected to the inlet of the gas collecting box 420, and injects the second fuel (hydrogen) toward the gas collecting box 420, and the flow rate of the second fuel (hydrogen) can be reduced in the gas collecting box 420. The third channel 350 is provided with a through hole 324, that is, the outer periphery of the mixing tube 320 located in the avoidance hole is provided with a through hole 324, and the outlet of the gas collecting box 420 is connected to the through hole 324, so that the gas collecting box 420 and the third channel 350 are connected. The second fuel (hydrogen) enters the gas collecting box 420 through the fourth nozzle 410, and after the flow rate is reduced in the gas collecting box 420, it enters the combustion chamber body 100 through the outlet of the gas collecting box 420, the through hole 324, and the outlet of the third channel 350. The fourth nozzle 410 includes a straight-injection nozzle.

[0044] It should be noted that at this time, the air inlet of the third channel 350 is the air inlet of the fourth channel 430, that is, the air enters the third channel 350 through the third tangential inlet 321, the first opening 322 and the second opening 323 on the mixing tube 320, and mixes with the second fuel (hydrogen) at the outlet of the gas collecting box 420, and then enters the combustion chamber body 100 after mixing. The second fuel (hydrogen) diffuses into the combustion chamber body 100, which is lean combustion, forming a short flame. The high molecular diffusion rate and high flame speed of hydrogen can achieve better mixing and lower high-temperature gas residence time and combustion temperature, greatly reducing the amount of NOx generated. When the combustion chamber uses the first fuel (kerosene) for combustion, the fourth nozzle 410 inputs air into the gas collecting box 420 at this time, which can be mixed with the first fuel (kerosene) in the third channel 350 on the one hand; on the other hand, it can prevent the first fuel (kerosene) in the third channel 350 from entering the gas collecting box 420 through the outlet of the gas collecting box 420.

[0045] The first nozzle 211, the second nozzle 212, the third nozzle 310 and the fourth nozzle 410 of the embodiment of the present invention make the first fuel (kerosene) and the second fuel (hydrogen) more evenly distributed in space, avoiding local oil-rich or hydrogen-rich areas and reducing the generation of soot. In addition, the temperature distribution in the combustion chamber body 100 can also be adjusted to improve uniformity.

[0046] In a specific embodiment, the structure of the combustion chamber body 100 is as follows: Figure 1 and Figure 2 As shown, the length is 135mm, the height is 90mm, the length of the top arc segment is 388.4014mm, and the length of the bottom arc segment is 208.3932mm. The diameter of the third nozzle 310 in the first main combustion stage device 300 is 0.945mm, and the length extending into the mixing tube 320 is 8.2m. There are 12 third tangential inlets 321 of the mixing tube 320, and the third tangential inlet 321 is a circular hole with a diameter of 2mm. The first opening 322 is a rectangular opening with a length of 4.5mm and a width of 1mm, and the number is 24; the second opening 323 is also a rectangular opening with a length of 6mm and a width of 1mm, and the number is 24. At the end of each mixing tube 320, 10 through holes 324 with a diameter of 1mm are provided for the second fuel (hydrogen) to be sprayed out. The diameter of the fourth nozzle 410 in the second main combustion stage device 400 is 4.5mm. The diameter of the first nozzle 211 in the pre-combustion stage device 200 is 0.3 mm, and the diameter of the second nozzle 212 is 2.5 mm.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-fuel center-staged multi-flame combustion chamber, characterized in that: include: A combustion chamber body, a pre-combustion stage device, a first main combustion stage device and a second main combustion stage device, wherein the pre-combustion stage device, the first main combustion stage device and the second main combustion stage device are respectively arranged at the front end of the combustion chamber body; The pre-combustion stage device comprises a pre-combustion stage assembly and a pre-combustion mixing chamber, the pre-combustion mixing chamber is connected to the combustion chamber body, a first channel and a second channel are arranged in the pre-combustion stage assembly, the first channel is connected to the pre-combustion mixing chamber, the first channel, the pre-combustion mixing chamber and the combustion chamber body are coaxially arranged, and a first fuel enters the pre-combustion mixing chamber through the first channel; the pre-combustion mixing chamber is arranged at the periphery of the second channel, the second channel is connected to the pre-combustion mixing chamber, and a second fuel enters the pre-combustion mixing chamber through the second channel; A third channel is provided in the first main combustion stage device, and a fourth channel is provided in the second main combustion stage device. The fourth channel is connected to the third channel, and the third channel is connected to the combustion chamber body. The first fuel enters the combustion chamber body through the third channel, and the second fuel enters the combustion chamber body through the fourth channel and the third channel.

2. The dual-fuel center-staged multi-flame combustion chamber according to claim 1, characterized in that: There are a plurality of the first main combustion stage devices, and the plurality of the first main combustion stage devices are arranged around the periphery of the pre-combustion stage device.

3. The dual-fuel center-staged multi-flame combustion chamber according to claim 1, characterized in that: The pre-combustion stage assembly comprises a first nozzle, a second nozzle, an annular air collecting chamber, a first swirler and a first venturi, wherein the annular air collecting chamber is arranged at the front end of the pre-combustion mixing chamber, the first swirler is arranged at a side of the annular air collecting chamber away from the pre-combustion mixing chamber, the first swirler and the annular air collecting chamber form the first channel; the first nozzle is connected to the inlet of the first channel; the blades of the first swirler form a first tangential inlet, and air enters the first channel through the first tangential inlet; The first venturi is arranged between the annular air collecting chamber and the pre-combustion mixing chamber, the second nozzle is connected to the inlet of the annular air collecting chamber, a plurality of flow channels are arranged in the side wall of the first venturi, the inlet of each flow channel is connected to the outlet of the annular air collecting chamber, and the outlet of each flow channel is arranged toward the pre-combustion mixing chamber.

4. The dual-fuel center-staged multi-flame combustion chamber according to claim 3, characterized in that: The pre-combustion stage assembly includes a second swirler, which is arranged between the annular air collecting chamber and the pre-combustion mixing chamber. The blades of the second swirler form a second tangential inlet, and air enters the pre-combustion mixing chamber through a gap between an inner wall of the second swirler and an outer wall of the first venturi.

5. The dual-fuel center-staged multi-flame combustion chamber according to claim 1, characterized in that: The first main combustion stage device comprises a third nozzle and a mixing tube, the third channel is arranged in the mixing tube, the third nozzle is communicated with the third channel, and a third tangential inlet is arranged at the front end of the mixing tube.

6. The dual-fuel center-staged multi-flame combustion chamber according to claim 5, characterized in that: The first main combustion stage device also includes a sleeve, which is arranged in the mixing tube, the inlet of the sleeve is connected to the third tangential inlet and the third nozzle respectively, and the outlet of the sleeve is connected to the outlet of the mixing tube; the cross-sectional area of ​​the sleeve gradually decreases along the direction from the inlet of the sleeve toward the outlet of the sleeve.

7. The dual-fuel center-staged multi-flame combustion chamber according to claim 6, characterized in that: The outer wall of the mixing tube is further provided with a plurality of first openings, which are arranged at intervals along the circumference of the mixing tube and are located between the outlet of the sleeve and the outlet of the mixing tube.

8. The dual-fuel center-staged multi-flame combustion chamber according to claim 6, characterized in that: The first main combustion stage device further includes a second venturi tube, which is disposed in the mixing tube, wherein an inlet of the second venturi tube is communicated with an outlet of the sleeve, and an outlet of the second venturi tube is communicated with an outlet of the mixing tube.

9. The dual-fuel center-staged multi-flame combustion chamber according to claim 8, characterized in that: The outer wall of the mixing tube is further provided with a plurality of second openings, the plurality of second openings are arranged at intervals along the circumference of the mixing tube, and the second openings are arranged close to the outlet of the second venturi tube.

10. The dual-fuel center-staged multi-flame combustion chamber according to claim 1, characterized in that: The second main combustion stage device includes a fourth nozzle and an air collecting box, wherein the air collecting box is arranged between the pre-combustion mixing chamber and the combustion chamber body, the fourth nozzle is connected to the inlet of the air collecting box, and the outlet of the air collecting box is connected to the third channel.

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