A highly compact lobe mixer

Abstract

This invention discloses a high-efficiency, compact lobe mixer, which consists of a lobe, an air distribution plate, a first air distribution hole, a primary fuel distribution chamber, a fuel mixing pipe, a fuel inlet pipe, a flow channel, a flow channel pipe, a flange, mounting holes, a second air distribution hole, a film gas hole, a secondary fuel distribution chamber, a fuel branch pipe, and fuel holes. It enables rapid, efficient, and low-pressure-loss mixing of fuel and air. The mixer utilizes the vortex development at the lobe tip for fuel and air mixing. Air enters the mixing channel at a predetermined velocity after being rectified by the air distribution hole. The fuel distribution chamber is attached to the outer wall of the lobe and connected to the fuel pipe at the lobe tip via the fuel branch pipe, ensuring uniform fuel distribution and lobe structural strength. The number, diameter, angle, and spatial position of the fuel holes at the lobe tip are determined based on the area of ​​the two ducts separated by the lobe. A film gas hole is provided at the outlet of the mixing channel, serving both to enhance mixing and for structural cooling.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, specifically to a high-efficiency, compact lobe mixer. Background Technology

[0002] As gas turbine outlet temperatures continue to rise, and to meet increasingly stringent low-emission requirements, axial staged combustion technology can achieve the goal of lower emissions at higher combustion temperatures. A key issue for axial staged combustion technology is that the unburned secondary gases and the mainstream high-temperature flue gas must be uniformly mixed before combustion can fully realize the low NOx advantages of this technology. Therefore, the uniform mixing characteristics of fuel and air are crucial for improving gas turbine performance and reducing emissions.

[0003] Chinese Invention Patent: CN201610416346.9 A rapid blending device for pyrolysis fuel gas and air includes an outer shell, an inner shell, and a lobe mixer. The inner shell is disposed within the outer shell, forming a swirling air inlet channel between the inner and outer shells. The lobe mixer includes an inner channel wall for the lobe blending structure, a convex lobe structure, and a concave lobe structure. The convex and concave lobe structures are arranged alternately to form an annular structure. The inner channel wall of the lobe blending structure connects to the annular structure, forming a pyrolysis fuel gas inlet that connects to the rich-fuel pyrolysis combustion chamber. The lobe mixer is disposed within the inner shell, forming a lobe blended air channel between the inner channel wall and the inner shell. An oblique radial channel with swirling blades is provided at the outlet of the lobe mixer, and the outlet of the oblique radial channel is a pyrolysis fuel gas-air blended gas outlet. This invention can achieve rapid blending of pyrolysis fuel gas and air, reducing NOx formation in the lean-fuel zone.

[0004] Chinese Invention Patent: CN202111104516.7 An enhanced mixing device for a solid rocket ramjet engine. The lobe mixing device has a simple structure and is easy to manufacture. Based on the theory of vortex motion, the lobe mixer generates vortices that interact with the mainstream, increasing the residence time of primary combustion gas in the afterburner, thereby improving combustion efficiency.

[0005] As can be seen from the two patents above, the existing technology uses two different media on the inner and outer sides of the lobe, which cannot achieve rapid and efficient mixing in a small space. The mixing is uneven and the efficiency is low. To improve the uniformity of fuel and air mixing, the lobe structure has been adopted as a passive control strategy. Due to limitations such as structure and cost, the space left for secondary fuel and air mixing is very limited. At the same time, it is necessary to ensure uniform mixing characteristics within a limited space. These realities pose significant challenges to the structure and performance requirements of the secondary nozzle. To address this, a high-efficiency and compact lobe mixer is provided, which integrates the fuel chamber into the mixer wall. The compact structure can meet various inlet requirements. Fuel is distributed according to the flow channel area ratio at the mixing point, resulting in more uniform and efficient mixing. The fuel chamber at the top of the lobe is transported through a fuel branch pipe, which provides both structural support and uniform air distribution. The outlet gas film orifice can enhance mixing and provide cooling. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a highly efficient and compact beam mixer to solve the problems mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-efficiency compact lobe mixer, comprising a lobe mixer, wherein the lobe mixer is composed of a lobe, an air distribution plate, a first air distribution hole, a primary fuel distribution chamber, a fuel mixing pipe, a fuel inlet pipe, a flow channel, a flow channel pipe, a flange, a mounting hole, a second air distribution hole, a film gas hole, a secondary fuel distribution chamber, a fuel branch pipe, and a fuel hole.

[0008] As a preferred embodiment of the present invention, the middle part of the lobe mixer is provided with a lobe, and the outer wall of the lobe is provided with a primary fuel distribution chamber. The primary fuel distribution chamber is connected to the secondary fuel distribution chamber in the fuel mixing pipe through a fuel branch pipe.

[0009] As a preferred embodiment of the present invention, the bottom of the beam mixer is connected to a flow channel tube, the flow channel tube is provided with a flow channel, and the flow channel tube is provided with a plurality of air film holes.

[0010] As a preferred embodiment of the present invention, the top of the lobe mixer is provided with an air distribution plate, the air distribution plate is uniformly provided with a plurality of first air distribution holes, and the outer side of the top of the lobe is uniformly provided with a plurality of second air distribution holes.

[0011] As a preferred embodiment of the present invention, the top of the lobe is provided with a fuel mixing tube, and the fuel mixing tube is provided with a plurality of fuel holes.

[0012] As a preferred embodiment of the present invention, the beam mixer is equipped with a flange, and mounting holes are provided on both sides of the flange.

[0013] In a preferred embodiment of the present invention, the arrangement of the fuel orifices is related to the areas of the two ducts separated by the lobe structure. The areas of the two ducts are: duct 1 area A1 and duct 2 area A2. The ratio of the areas of the two ducts is consistent with the ratio of the areas of the corresponding fuel mixing orifices, and the ratio of the area of ​​each channel constituting the duct to the ratio of the area of ​​its corresponding fuel orifice is also consistent. The areas of the channels constituting the duct are respectively the area of ​​channel 1 in the two ducts 1, A1 and A2. 1-1 Two culverts, one with a channel 2, have an area of ​​A. 1-2 Two culverts, 2 in total, 1 in the middle, with an area of ​​A 2-1 A culvert 2 has a channel area A. 2-2 .

[0014] As a preferred embodiment of the present invention, the distance between the air film hole and the mixer outlet is 10mm-20mm, the angle between the air film hole and the axial direction is 25-45°, the air flow rate through the air film hole accounts for 2-10% of the main air flow rate, and the size and number of air film holes are determined by the air flow rate.

[0015] As a preferred embodiment of the present invention, the second air distribution hole is in the shape of a capsule hole with a single hole area of ​​13mm²; the first air distribution hole is a round hole with a diameter of 3mm.

[0016] The beneficial effects of this invention are as follows: The high-efficiency, compact lobe mixer of this invention can achieve rapid mixing of fuel and air with high efficiency and low pressure loss. The mixer utilizes the vortex development at the top of the lobe to mix fuel and air. After being rectified by the air distribution holes, the air enters the mixing channel at a predetermined speed. The fuel distribution chamber is attached to the outer wall of the lobe and is connected to the fuel pipe at the top of the lobe through a fuel branch pipe, ensuring uniform fuel distribution and the structural strength of the lobe. The number, diameter, angle, and spatial position of the fuel holes at the top of the lobe are determined based on the area of ​​the two ducts separated by the lobe. A film cooling hole is opened at the outlet of the mixing channel, which serves to enhance mixing and cool the structure. This invention can achieve a mixing non-uniformity (SMD) of less than 5% at the outlet space of the mixer while keeping the overall axial length no more than 1.5 times the outlet width. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the bottom structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the flow channel tube of the present invention;

[0019] Figure 3 This is a schematic diagram of the top structure of the present invention;

[0020] Figure 4 This is an exploded structural diagram of the present invention;

[0021] Figure 5 This is one of the cross-sectional views of the present invention;

[0022] Figure 6 This is a second cross-sectional view of the present invention;

[0023] Figure 7 This is a cross-sectional view of the lobe throat of the present invention.

[0024] In the figure: 100, 101, 102, 103, 104, 105, 106, 107, 109, 110, 111, 112, 113, 114, 115, 116.

[0025] A1 - Area of ​​duct 1; A2 - Area of ​​duct 2; A 1-1 -Area of ​​passage 1 in culvert 1; A 1-2 -Area of ​​passage 2 in culvert 1; A 2-1 -Area of ​​passage 1 in culvert 2; A 2-2 -Area of ​​the passageway 2 in culvert 2. Detailed Implementation

[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0027] Example: Please refer to Figure 1-7 The present invention provides a technical solution: a high-efficiency compact lobe mixer, comprising a lobe mixer 100, which is composed of a lobe 101, an air distribution plate 102, a first air distribution hole 103, a primary fuel distribution chamber 104, a fuel mixing pipe 105, a fuel inlet pipe 106, a flow channel 107, a flow channel pipe 109, a flange 110, a mounting hole 111, a second air distribution hole 112, an air film hole 113, a secondary fuel distribution chamber 114, a fuel branch pipe 115, and a fuel hole 116.

[0028] The middle part of the lobe mixer 100 is provided with a lobe 101, and the outer wall of the lobe 101 is provided with a primary fuel distribution chamber 104. The primary fuel distribution chamber 104 is connected to the secondary fuel distribution chamber 114 in the fuel mixing pipe 105 through the fuel branch pipe 115.

[0029] The bottom of the beam mixer 100 is connected to a flow channel 109, which contains a flow channel 107 and has several air film holes 113.

[0030] The top of the beam mixer 100 is provided with an air distribution plate 102, and a plurality of first air distribution holes 103 are evenly provided on the air distribution plate 102. A plurality of second air distribution holes 112 are evenly provided on the outer side of the top of the beam 101.

[0031] The top of the lobe 101 is provided with a fuel mixing pipe 105, and the fuel mixing pipe 105 is provided with a number of fuel holes 116.

[0032] A flange 110 is installed on the beam mixer 100, and mounting holes 111 are provided on both sides of the flange 110.

[0033] The arrangement of the fuel orifice 116 is related to the area of ​​the two ducts separated by the lobe structure. The areas of the two ducts are: duct 1 area A1 and duct 2 area A2. The ratio of the two duct areas is consistent with the ratio of the corresponding fuel mixing orifice areas. The ratio of the area of ​​each channel constituting the duct to the ratio of its corresponding fuel orifice area is also consistent. The area of ​​each channel constituting the duct is the area of ​​channel 1 in the two ducts 1, A1 and A2 respectively. 1-1 Two culverts, one with a channel 2, have an area of ​​A. 1-2 Two culverts, 2 in total, 1 in the middle, with an area of ​​A 2-1 A culvert 2 has a channel area A. 2-2 .

[0034] The distance between the air film hole 113 and the mixer outlet is 10mm-20mm, the angle between the air film hole 113 and the axial direction is 25-45°, the air flow through the air film hole 113 accounts for 2-10% of the main air flow, and the size and number of air film holes 113 are determined by the air flow.

[0035] The second air distribution hole 112 is in the shape of a capsule hole with a single hole area of ​​13mm²; the first air distribution hole 103 is a round hole with a diameter of 3mm.

[0036] Working principle: Air first enters the air distribution chamber through the first air distribution hole 103 on the air distribution plate 102. In this embodiment, the first air distribution hole 103 consists of 194 circular holes with a diameter of 3mm. The air velocity is controlled at about 20m / s. After passing through the air distribution plate 102, it enters the nozzle flow channel through the second air distribution hole 112 on the inlet wall of the internal flow channel and the air inlet, ready to be mixed with fuel. In this embodiment, the second air distribution hole 112 consists of 30 capsule holes with an area of ​​13mm². The air velocity is controlled within 40m / s by the inlet area and the distribution hole area. After two stages of air distribution, the air velocity and flow rate entering the mixing flow channel are relatively uniform, thereby ensuring the mixing characteristics of the mixer.

[0037] Fuel first enters the primary fuel distribution chamber 104 through the inlet of the fuel inlet pipe 106. The primary fuel distribution chamber 104 is an annular cavity located on the wall of the corrugated nozzle. The cross-sectional area of ​​the annular cavity can be adjusted according to actual conditions. In this embodiment, the fuel velocity in the annular cavity is controlled at about 60 m / s by the cross-sectional area of ​​the annular cavity. The fuel inlet pipe 106 can also be opened at any position on the primary fuel distribution chamber 104 according to actual conditions. The fuel branch pipe 115 is located between the primary fuel distribution chamber 104 and the corrugated nozzle 101. After the fuel passes through the fuel branch pipe 115, it is guided to each crest of the corrugated nozzle structure and then enters the secondary fuel distribution chamber 114. Finally, it is ejected from the fuel hole 116 on the fuel mixing pipe 105 and mixed with air in the flow channel 107 of the flow channel pipe 109. The cross-section of the secondary fuel distribution chamber 114 is spindle-shaped, and the geometry along the flow direction protrudes further to avoid backfire. In this embodiment, the fuel velocity in the fuel mixing pipe 105 at the top of the lobe is controlled at around 80 m / s by the cross-sectional area of ​​the pipe.

[0038] The perforation pattern of fuel orifice 116 and the channel area (A) of each duct 1-1 A 1-2 A 2-1 A 2-2 The ratio of the area A1 of duct 1 to the area A2 of duct 2 is the same as the ratio of the areas of their corresponding fuel orifices. Furthermore, the amount of fuel allocated to each channel forming the duct is determined by the area of ​​that channel to ensure mixing characteristics and prevent uneven local equivalence ratios after fuel and air are sprayed through the secondary nozzle. In this embodiment, the fuel mixing orifices consist of small holes with diameters of 0.8mm, 0.9mm, 1mm, and 1.2mm. The outlet velocity of the mixing orifices is approximately 120m / s. From the fuel inlet to the outlet of the mixing orifices, the fuel velocity gradually increases without drastic changes, thus ensuring the mixing characteristics of the mixer.

[0039] The air film orifice 113 consists of 36 30° oblique holes with a diameter of 1 mm, which can enhance mixing and a certain jet depth, while also protecting the secondary nozzle. In this embodiment, the mixer outlet width is 42 mm and the axial length is 63 mm, which can be applied to various applications. Furthermore, through numerical simulation calculations, the mixing non-uniformity (SMD) at the mixer outlet can reach below 5%.

[0040] This invention relates to a high-efficiency, compact lobe mixer that enables rapid, low-pressure-loss mixing of fuel and air. The mixer utilizes the vortex development at the lobe tip for fuel and air mixing. Air, after being rectified by air distribution holes, enters the mixing channel at a predetermined velocity. The fuel distribution chamber is attached to the outer wall of the lobe and connected to the fuel pipe at the lobe tip via a fuel branch pipe, ensuring uniform fuel distribution and lobe structural strength. The number, diameter, angle, and spatial position of the fuel holes at the lobe tip are determined based on the area of ​​the two ducts separated by the lobe. A film cooling hole is provided at the outlet of the mixing channel, serving both to enhance mixing and for structural cooling. This invention achieves a mixing non-uniformity (SMD) of less than 5% at the mixer outlet while maintaining an overall axial length not exceeding 1.5 times the outlet width.

[0041] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A high-efficiency, compact beam mixer, comprising a beam mixer (100), characterized in that: The lobe mixer (100) is composed of a lobe (101), an air distribution plate (102), a first air distribution hole (103), a primary fuel distribution chamber (104), a fuel mixing pipe (105), a fuel inlet pipe (106), a flow channel (107), a flow channel pipe (109), a flange (110), a mounting hole (111), a second air distribution hole (112), an air film hole (113), a secondary fuel distribution chamber (114), a fuel branch pipe (115), and a fuel hole (116). The middle part of the lobe mixer (100) is provided with a lobe (101), and the outer wall of the lobe (101) is provided with a primary fuel distribution chamber (104). The primary fuel distribution chamber (104) is connected to the secondary fuel distribution chamber (114) in the fuel mixing pipe (105) through a fuel branch pipe (115). The bottom of the beam mixer (100) is connected to a flow channel (109), the flow channel (109) is provided with a flow channel (107), and the flow channel (109) is provided with a plurality of air film holes (113). The top of the beam mixer (100) is provided with an air distribution plate (102), and a plurality of first air distribution holes (103) are uniformly provided on the air distribution plate (102), and a plurality of second air distribution holes (112) are uniformly provided on the outer side of the top of the beam (101). The top of the lobe (101) is provided with a fuel mixing tube (105), and the fuel mixing tube (105) is provided with a plurality of fuel holes (116). The beam mixer (100) is equipped with a flange (110), and mounting holes (111) are provided on both sides of the flange (110).

2. The high-efficiency compact beam mixer according to claim 1, characterized in that: The arrangement of the fuel orifices (116) is related to the areas of the two ducts separated by the lobe structure. The areas of the two ducts are: duct 1 area A1 and duct 2 area A2. The ratio of the areas of the two ducts is consistent with the ratio of the areas of the corresponding fuel mixing orifices. The ratio of the area of ​​each channel that makes up the duct is also consistent with the ratio of the area of ​​its corresponding fuel orifice. The area of ​​each channel that makes up the duct is the area of ​​channel 1 in the two ducts 1, A1 and A2 respectively. 1-1 Two culverts, one with a channel 2, have an area of ​​A. 1-2 Two culverts, 2 in total, 1 in the middle, with an area of ​​A 2-1 A culvert 2 has a channel area A. 2-2 .

3. The high-efficiency compact beam mixer according to claim 1, characterized in that: The distance between the air film hole (113) and the mixer outlet is 10mm-20mm, the angle between the air film hole (113) and the axial direction is 25-45°, the air flow through the air film hole (113) accounts for 2-10% of the main air flow, and the size and number of air film holes (113) are determined by the air flow.

4. The high-efficiency compact beam mixer according to claim 1, characterized in that: The second air distribution hole (112) is in the shape of a capsule hole with a single hole area of ​​13mm²; the first air distribution hole (103) is a round hole with a diameter of 3mm.

Images