Pre-combustion chamber structure capable of efficiently refluxing mixed gas

Abstract

The invention discloses an efficient mixed gas backflow precombustion chamber structure which comprises an ignition electrode, a fuel nozzle, a rectifying plate and a shell, the ignition electrode and the fuel nozzle extend into the shell to be connected, the rectifying plate is arranged in an inner cavity of the shell and connected with the ignition electrode, and a precombustion chamber air inlet and a flame jet flow channel are formed in the shell. According to the pre-combustion chamber, invalid atomization and mixing losses can be reduced, turbulent kinetic energy in the backflow area is used for assisting fuel oil diffusion, dependence on the oil supply pressure of a nozzle is reduced, it is guaranteed that the oil-gas mixture concentration of fuel oil and air mixed gas in the backflow area is within the combustible range, and the mixed gas in the shell is easily ignited by a fire core and stably combusted. After incoming flow air is rectified by the rectifying plate, a backflow area is formed in front of the ignition electrode, fuel concentration distribution is induced by turbulent kinetic energy of the backflow area, a certain distance is kept between an initial fire core and the ignition end face of the electrode while stable generation of the initial fire core is guaranteed, and carbon deposition on the ignition end face of the electrode is avoided.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine technology, and in particular relates to a pre-combustion chamber structure with high efficiency recirculation mixing. Background Technology

[0002] Aero engines frequently face cold starts in extremely cold environments with low-temperature fuel. Under these conditions, the fuel viscosity is higher, the inlet air temperature is lower, and the ignition conditions deviate from the design requirements, increasing the difficulty of ignition. In traditional aero engine combustion chambers, the ignition system typically uses direct injection, injecting fuel into the combustion chamber to mix with air, and then igniting it via an electric spark. The combustion chamber is relatively large, requiring thorough mixing of fuel and air for ignition. This necessitates a high fuel flow rate to ensure mixing efficiency, and the fuel nozzles must operate under high pressure or be designed with dual fuel lines to ensure atomization quality and high fuel flow rate. Simultaneously, the ignition electrodes require higher energy to ensure reliable ignition, increasing energy consumption, fuel supply system complexity, and ignition electrode reliability. Therefore, providing appropriate ignition energy to ensure reliable ignition in the combustion chamber under extreme environmental conditions is crucial.

[0003] Patent document US10208652B2 discloses a pre-combustion chamber body for an internal combustion engine. This pre-combustion chamber body has a pre-combustion chamber. The pre-combustion chamber body also has a flow transfer channel that can fluidly connect the pre-combustion chamber and the outside of the pre-combustion chamber body. The pre-combustion chamber body has at least one return channel that can fluidly connect the pre-combustion chamber and the flow transfer channel. In this document, a mixture of fuel and air from the main combustion chamber is supplied to the pre-combustion chamber via the flow channel that fluidly connects the pre-combustion chamber and the main combustion chamber. The ignition device and the upper fuel supply port in the pre-combustion chamber are both positioned downwards, and there is no return zone in the pre-combustion chamber for further mixing of fuel and air. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a pre-combustion chamber structure with high efficiency recirculation mixing.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides a high-efficiency recirculation mixing pre-combustion chamber structure, including an ignition electrode, a fuel nozzle, a rectifier plate and a housing. The ignition electrode and the fuel nozzle are both inserted into and connected to the housing. The rectifier plate is disposed in the inner cavity of the housing and is connected to the ignition electrode. The housing is provided with a pre-combustion chamber air inlet and a flame jet channel.

[0007] Preferably, the inner cavity of the housing is provided with a partition, one end of which is connected to the ignition electrode. The partition, the ignition electrode and the rectifier plate divide the inner cavity of the housing into an airflow channel and a recirculation zone. The inlet end of the airflow channel is connected to the air inlet of the pre-combustion chamber, the outlet end of the airflow channel is connected to the inlet end of the recirculation zone at the fuel nozzle, and the outlet end of the recirculation zone is connected to the flame jet channel.

[0008] Preferably, there is a gap between the end face of the fuel nozzle and the edge of the recirculation zone.

[0009] Preferably, the partition is arranged in an arc shape.

[0010] Preferably, the ignition electrode is disposed above the housing, and the fuel injector is disposed on the left side of the housing, with the ignition electrode and the fuel injector forming an angle θ. e It is an obtuse angle.

[0011] Preferably, the angle θ e The angle is 100 to 130°.

[0012] Preferably, the rectifier plate is inclined to the axis of the fuel nozzle.

[0013] Preferably, the housing width d s For the shell length l s 0.1 to 0.9 times.

[0014] Preferably, the ignition electrode is a semiconductor electrode with a single spark energy of not less than 0.1J.

[0015] The beneficial effects of this invention are as follows:

[0016] The pre-combustion chamber of this invention features efficient fuel mixing and low ignition energy consumption in the recirculation zone. Air is supplied to the pre-combustion chamber through an external duct channel outside the combustion chamber, and the air volume is carefully controlled to limit the fuel-air mixture ratio within the pre-combustion chamber to a suitable range, preventing ablation of the casing wall. The flat, round pre-combustion chamber casing and rectifier plate design create a recirculation vortex near the ignition electrode, inducing a suitable fuel concentration distribution. The fuel nozzle is positioned at an obtuse angle to the ignition point in front of the recirculation zone, directly injecting atomized fuel into the recirculation zone. The electrode ignition nucleus ignites the mixed fuel gas in the recirculation zone. A recirculation vortex is generated within the flat, round pre-combustion chamber casing, making it easier for the ignition nucleus to ignite the mixture within the casing and ensure stable combustion. Finally, a high-energy flare is formed within the pre-combustion chamber and then ejected through the jet outlet, ultimately igniting the combustion chamber. This pre-combustion chamber has a simple structure, reduces ineffective atomization and mixing losses, utilizes the turbulent kinetic energy of the recirculation zone to assist fuel diffusion, reduces dependence on nozzle fuel supply pressure, and ensures that the fuel-air mixture concentration within the flammable range in the recirculation zone, resulting in high ignition reliability. Attached Figure Description

[0017] Figure 1 This is a cross-sectional structural schematic diagram of the present invention;

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

[0019] Figure 3 This is a schematic diagram of the airflow direction of the present invention;

[0020] Figure 4 This is a schematic diagram of the structure of the present invention;

[0021] Figure 5 This is a schematic diagram of the width of the present invention;

[0022] In the figure: 1-Ignition electrode, 101-Ignition end face, 2-Fuel nozzle, 3-Rectifier plate, 4-Housing shell, 5-Pre-combustion chamber air inlet, 6-Flame jet channel, 7-Baffle plate, 8-Airflow channel, 9-Recirculation zone, 10-Combustion chamber outer duct channel, 11-Combustion chamber casing, 12-Flame tube. Detailed Implementation

[0023] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0024] Example 1:

[0025] like Figures 1 to 5 As shown, a high-efficiency recirculating pre-combustion chamber structure includes an ignition electrode 1, a fuel nozzle 2, a rectifier plate 3, and a housing 4. The ignition electrode 1 and the fuel nozzle 2 both extend into and are connected to the housing 4. The rectifier plate 3 is disposed in the inner cavity of the housing 4 and is connected to the left side of the ignition electrode 1. The rectifier plate 3 is manufactured by 3D printing. The housing 4 is provided with a pre-combustion chamber air inlet 5 and a flame jet channel 6.

[0026] The fuel nozzle 2 can use conventional fuels such as aviation kerosene or diesel, with a fuel mass flow rate of 7.56 kg / h and a fuel outlet injection velocity of 8 m / s. The fuel nozzle 2 is located in front of the recirculation zone 9, and the atomized fuel is directly injected into the recirculation zone 9. The electrode flame core ignites the mixed combustion gas in the recirculation zone, forming a high-temperature torch, which is then sprayed into the flame tube 12 through the flame jet channel 6 and finally ignites the main combustion chamber.

[0027] The pre-combustion chamber shell 4 is flat and round. A partition 7 is installed inside the shell 4. One end of the partition 7 is connected to the bottom of the ignition electrode 1. The partition 7, ignition electrode 1, and rectifier plate 3 divide the inner cavity of the shell 4 into an airflow channel 8 and a recirculation zone 9. The inlet end of the airflow channel 8 is connected to the air inlet 5 of the pre-combustion chamber, and the outlet end of the airflow channel 8 is connected to the inlet end of the recirculation zone 9 at the fuel nozzle 2. The outlet end of the recirculation zone 9 is connected to the flame jet channel 6. The maximum height h of the airflow channel 8 is... efThe diameter is 5mm to ensure a suitable contact area between the fuel nozzle 2 and the incoming air. It should not be too small, otherwise excessive flow resistance will hinder the formation of the recirculation zone 9. The outlet diameter d of the flame jet channel 6... o It has a 20mm diameter and provides a high-energy jet flame with a suitable jet velocity.

[0028] The mainstream air entering the pre-combustion chamber air inlet 5 is supplied by the combustion chamber outer duct 10 on one side of the combustion chamber casing 11. At the same time, the air volume is reasonably controlled to limit the fuel gas ratio in the pre-combustion chamber to a suitable range, so as to avoid the ablation of the casing 4 wall. The air flow rate is controlled at 6.9 kg / h. The outlet end of the flame jet channel 6 extends into the flame tube 12. After the incoming air is rectified by the rectifier plate 3, a recirculation zone 9 is formed in front of the ignition electrode 1. The turbulent kinetic energy of the recirculation zone 9 is used to induce the fuel concentration distribution. While ensuring the stable generation of the initial flame core, the initial flame core is kept at a certain distance from the ignition end face 101 of the ignition electrode 1 to avoid the generation of carbon deposits on the ignition end face 101 of the ignition electrode 1.

[0029] The fuel nozzle 2 has a 5mm gap between its end face and the edge of the recirculation zone 9, ensuring that fuel is directly injected into the recirculation zone, reducing ineffective atomization, and improving combustion efficiency. Figure 4 As shown, the distance between the right end of fuel nozzle 2 and the nearest vertical line is the gap.

[0030] The partition 7 is arranged in an arc shape.

[0031] The ignition electrode 1 is disposed above the housing 4, and the fuel nozzle 2 is disposed on the left side of the housing 4. The angle θ between the axes of the ignition electrode 1 and the fuel nozzle 2 is... e It is an obtuse angle.

[0032] The angle θ e The angle is 120° to prevent the ignition position from shifting and burning the casing 4.

[0033] The angle θ0 between the rectifier plate 3 and the fuel nozzle 2 axis is 5°, forming a slightly expanded airflow channel 8 outlet. The larger end is the end of the rectifier plate 3 closer to the fuel nozzle 2, which reduces the separation when the gas flow direction changes, and at the same time guides the flow to the combustion area below the ignition electrode 1.

[0034] The height h of the shell 4 s It is 80mm long, and the shell has a length of 4 liters. s It is 60mm long, and the shell width is d. s It is 25mm.

[0035] The ignition electrode 1 is a semiconductor electrode with a single spark energy of not less than 0.1J. The spark length of the ignition electrode 1 is 15mm, so that the spark range largely overlaps with the area of ​​the recirculation region 9.

[0036] Example 2:

[0037] like Figures 1 to 5 As shown, a high-efficiency recirculating pre-combustion chamber structure includes an ignition electrode 1, a fuel nozzle 2, a rectifier plate 3, and a housing 4. The ignition electrode 1 and the fuel nozzle 2 both extend into and are connected to the housing 4. The rectifier plate 3 is disposed in the inner cavity of the housing 4 and is connected to the ignition electrode 1. The rectifier plate 3 is manufactured by 3D printing. The housing 4 is provided with a pre-combustion chamber air inlet 5 and a flame jet channel 6.

[0038] The fuel nozzle 2 can use conventional fuels such as aviation kerosene or diesel, with a fuel mass flow rate of 0.18 kg / h and a fuel outlet injection velocity of 5 m / s. The fuel nozzle 2 is located in front of the recirculation zone 9, and the atomized fuel is directly injected into the recirculation zone 9. The electrode flame core ignites the mixed gas in the recirculation zone, forming a high-temperature torch, which is then sprayed into the flame tube 12 through the flame jet channel 6 and finally ignites the main combustion chamber.

[0039] The pre-combustion chamber shell 4 is flat and round. A partition 7 is installed inside the shell 4. One end of the partition 7 is connected to the ignition electrode 1. The partition 7, ignition electrode 1, and rectifier plate 3 divide the inner cavity of the shell 4 into an airflow channel 8 and a recirculation zone 9. The inlet end of the airflow channel 8 is connected to the air inlet 5 of the pre-combustion chamber. The outlet end of the airflow channel 8 connects to the inlet end of the recirculation zone 9 at the fuel nozzle 2. The outlet end of the recirculation zone 9 connects to the flame jet channel 6. The maximum height h of the airflow channel 8 is... ef The diameter is 3mm to ensure a suitable contact area between the fuel nozzle 2 and the incoming air. It should not be too small, otherwise excessive flow resistance will hinder the formation of the recirculation zone 9. The outlet diameter d of the flame jet channel 6... o It provides a high-energy jet flame with a diameter of 10mm and a suitable jet velocity.

[0040] The mainstream air entering the pre-combustion chamber air inlet 5 is supplied by the combustion chamber outer duct 10 on one side of the combustion chamber casing 11. At the same time, the air volume is reasonably controlled to limit the fuel-to-gas ratio in the pre-combustion chamber to a suitable range, so as to avoid the ablation of the casing 4 wall. The air flow rate is controlled at 3.6 kg / h. The outlet end of the flame jet channel 6 extends into the flame tube 12. After the incoming air is rectified by the rectifier plate 3, a recirculation zone 9 is formed in front of the ignition electrode 1. The turbulent kinetic energy of the recirculation zone 9 is used to induce the fuel concentration distribution. While ensuring the stable generation of the initial flame core, the initial flame core is kept at a certain distance from the ignition end face 101 of the ignition electrode 1 to avoid the generation of carbon deposits on the ignition end face 101 of the ignition electrode 1.

[0041] The fuel nozzle 2 has a 3mm gap between its end face and the edge of the recirculation zone 9, ensuring that fuel is directly injected into the recirculation zone, reducing ineffective atomization, and improving combustion efficiency. Figure 4 As shown, the distance between the right end of fuel nozzle 2 and the nearest vertical line is the gap.

[0042] The partition 7 is arranged in an arc shape.

[0043] The ignition electrode 1 is disposed above the housing 4, and the fuel nozzle 2 is disposed on the left side of the housing 4. The angle θ between the axes of the ignition electrode 1 and the fuel nozzle 2 is... e It is an obtuse angle.

[0044] The angle θ e The angle is 100° to avoid the ignition position shifting and burning the casing 4.

[0045] The angle θ0 between the rectifier plate 3 and the fuel nozzle 2 axis is 3°, forming a slightly expanded airflow channel 8 outlet. The larger end is the end of the rectifier plate 3 closer to the fuel nozzle 2, which reduces the separation when the gas flow direction changes, and at the same time guides the flow to the combustion area below the ignition electrode 1.

[0046] The height h of the shell 4 s It is 50mm long, and the shell has a length of 4. s It is 40mm thick, and the shell width is d. s It is 10mm.

[0047] The ignition electrode 1 is a semiconductor electrode with a single spark energy of not less than 0.1J. The spark length of the ignition electrode 1 is 10mm, so that the spark range largely overlaps with the area of ​​the recirculation region 9.

[0048] Example 3:

[0049] like Figures 1 to 5 As shown, a high-efficiency recirculating pre-combustion chamber structure includes an ignition electrode 1, a fuel nozzle 2, a rectifier plate 3, and a housing 4. The ignition electrode 1 and the fuel nozzle 2 both extend into and are connected to the housing 4. The rectifier plate 3 is disposed in the inner cavity of the housing 4 and is connected to the ignition electrode 1. The rectifier plate 3 is manufactured by 3D printing. The housing 4 is provided with a pre-combustion chamber air inlet 5 and a flame jet channel 6.

[0050] The fuel nozzle 2 can use conventional fuels such as aviation kerosene or diesel, with a fuel mass flow rate of 1.08 kg / h and a fuel outlet injection velocity of 10 m / s. The fuel nozzle 2 is located in front of the recirculation zone 9, and the atomized fuel is directly injected into the recirculation zone 9. The electrode flame core ignites the mixed combustion gas in the recirculation zone, forming a high-temperature torch, which is then sprayed into the flame tube 12 through the flame jet channel 6 and finally ignites the main combustion chamber.

[0051] The pre-combustion chamber shell 4 is flat and round. A partition 7 is installed inside the shell 4. One end of the partition 7 is connected to the ignition electrode 1. The partition 7, ignition electrode 1, and rectifier plate 3 divide the inner cavity of the shell 4 into an airflow channel 8 and a recirculation zone 9. The inlet end of the airflow channel 8 is connected to the air inlet 5 of the pre-combustion chamber. The outlet end of the airflow channel 8 connects to the inlet end of the recirculation zone 9 at the fuel nozzle 2. The outlet end of the recirculation zone 9 connects to the flame jet channel 6. The maximum height h of the airflow channel 8 is... ef The diameter is 6mm to ensure a suitable contact area between the fuel nozzle 2 and the incoming air. It should not be too small, otherwise excessive flow resistance will hinder the formation of the recirculation zone 9. The outlet diameter d of the flame jet channel 6... o It provides a high-energy jet flame with a diameter of 30mm and a suitable jet velocity.

[0052] The mainstream air entering the pre-combustion chamber air inlet 5 is supplied by the combustion chamber outer duct 10 on one side of the combustion chamber casing 11. At the same time, the air volume is reasonably controlled to limit the fuel-to-gas ratio in the pre-combustion chamber to a suitable range, so as to avoid the ablation of the casing 4 wall. The air flow rate is controlled at 10.8 kg / h. The outlet end of the flame jet channel 6 extends into the flame tube 12. After the incoming air is rectified by the rectifier plate 3, a recirculation zone 9 is formed in front of the ignition electrode 1. The turbulent kinetic energy of the recirculation zone 9 is used to induce the fuel concentration distribution. While ensuring the stable generation of the initial flame core, the initial flame core is kept at a certain distance from the ignition end face 101 of the ignition electrode 1 to avoid the generation of carbon deposits on the ignition end face 101 of the ignition electrode 1.

[0053] The fuel nozzle 2 has a 6mm gap between its end face and the edge of the recirculation zone 9, ensuring that fuel is directly injected into the recirculation zone, reducing ineffective atomization, and improving combustion efficiency. Figure 4 As shown, the distance between the right end of fuel nozzle 2 and the nearest vertical line is the gap.

[0054] The partition 7 is arranged in an arc shape.

[0055] The ignition electrode 1 is disposed above the housing 4, and the fuel nozzle 2 is disposed on the left side of the housing 4. The angle θ between the axes of the ignition electrode 1 and the fuel nozzle 2 is... e It is an obtuse angle.

[0056] The angle θ e The angle is 100-130° to avoid the ignition position shifting and burning the casing 4.

[0057] The angle θ0 between the rectifier plate 3 and the fuel nozzle 2 axis is 8°, forming a slightly expanded airflow channel 8 outlet. The larger end is the end of the rectifier plate 3 closer to the fuel nozzle 2, which reduces the separation when the gas flow direction changes, and at the same time guides the flow to the combustion area below the ignition electrode 1.

[0058] The height h of the shell 4 s It is 100mm long, and the shell has a length of 4 l.s It is 70mm long, and the shell width is d. s It is 40mm.

[0059] The ignition electrode 1 is a semiconductor electrode with a single spark energy of not less than 0.1J. The spark length of the ignition electrode 1 is 20mm, so that the spark range largely overlaps with the area of ​​the recirculation region 9.

Claims

1. A pre-combustion chamber structure for high-efficiency recirculation mixing, characterized in that: It includes an ignition electrode (1), a fuel nozzle (2), a rectifier plate (3) and a housing (4). The ignition electrode (1) and the fuel nozzle (2) are both inserted into the housing (4) and connected. The rectifier plate (3) is set in the inner cavity of the housing (4) and connected to the ignition electrode (1). The housing (4) is provided with a pre-combustion chamber air inlet (5) and a flame jet channel (6).

2. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 1, characterized in that: The inner cavity of the housing (4) is provided with a partition (7). One end of the partition (7) is connected to the ignition electrode (1). The partition (7), the ignition electrode (1) and the rectifier plate (3) divide the inner cavity of the housing (4) into an airflow channel (8) and a recirculation zone (9). The inlet end of the airflow channel (8) is connected to the air inlet (5) of the pre-combustion chamber. The outlet end of the airflow channel (8) is connected to the inlet end of the recirculation zone (9) at the fuel nozzle (2). The outlet end of the recirculation zone (9) is connected to the flame jet channel (6).

3. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 2, characterized in that: There is a gap between the end face of the fuel nozzle (2) and the edge of the recirculation zone (9).

4. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 2, characterized in that: The partition (7) is arranged in an arc shape.

5. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 1, characterized in that: The ignition electrode (1) is disposed above the housing (4), and the fuel nozzle (2) is disposed on the left side of the housing (4). The angle θ between the axis of the ignition electrode (1) and the axis of the fuel nozzle (2) is... e It is an obtuse angle.

6. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 5, characterized in that: The angle θ e The angle is 100 to 130°.

7. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 1, characterized in that: The rectifier plate (3) is inclined to the axis of the fuel nozzle (2).

8. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 1, characterized in that: The width d of the shell (4) s For the shell (4) length l s 0.1 to 0.9 times.

9. The pre-combustion chamber structure for high-efficiency recirculation mixing as described in claim 1, characterized in that: The ignition electrode (1) is a semiconductor electrode with a single spark energy of not less than 0.1J.

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