A flame detector structure

Abstract

The application belongs to the technical field of aero-engines, and particularly relates to a flame detector structure. A tail part of a probe tube of the flame detector is arranged in an outer channel with cooling air formed by a heat shield and a chamber of a thrust chamber, and a head part of the probe tube is arranged in an inner channel with flame on an inner side of the heat shield through the heat shield. A cavity stabilizer has a cavity with a radially inward opening formed by metal, and a bottom of the cavity has a through hole for the head part of the probe tube to extend into without contact. The cavity stabilizer is connected with a wire. A flame detector sealing seat includes a sleeve and a mounting edge formed by a radially outward extension of an end surface edge of the sleeve, the sleeve is sleeved on the probe tube, the flame detector sealing seat is made of insulating material, and a flame detector support seat is used to press and fix the flame detector sealing seat on an outer surface of the bottom of the cavity stabilizer. The heat protection performance of the flame detector is enhanced, and the stability, reliability and accuracy of long-term work of the flame detector are improved.

Description

Technical Field

[0001] This application belongs to the field of aero-engine technology, and specifically relates to a flame detector structure. Background Technology

[0002] Technical background of the present invention:

[0003] The afterburner of a military aircraft engine utilizes the exhaust gas from the main engine for refueling and combustion, providing additional thrust to the engine. With technological advancements, the design of afterburners has gradually moved towards integration and modularity, resulting in significant differences in internal structure compared to traditional afterburners. As the inlet flow temperature and velocity of afterburners increase, the requirements for the total pressure recovery coefficient become more stringent. Traditional flame detectors exhibit significant errors and cannot accurately detect these higher temperatures and velocities.

[0004] 1. Flame detectors are used to detect flames and are exposed to high temperatures for extended periods. Traditional flame detectors have their heads located far from the wall, extending deep into the airflow within the afterburner. The outer shell of the flame detector head lacks cooling protection, making its materials highly susceptible to ablation, reducing safety, and in severe cases, affecting functionality.

[0005] 2. Traditional flame detectors, in order to cool the outer casing and achieve insulation of the metal tube shell, while also considering the axial relative displacement between the casing and the heat shield during combustion, require airflow mixing and cooling holes at the heat shield that are larger than the diameter of the flame detector's metal tube. These cooling holes cause significant leakage of outer duct cooling air into the inner casing, reducing the utilization efficiency of the outer duct cooling air. The large amount of mixed-air cooling air affects the fuel-air ratio distribution in the afterburner flow field, reducing local fuel evaporation and impacting combustion efficiency.

[0006] 3. Traditional flame detectors are located in environments with high temperatures and high speeds, resulting in unstable measurement values. Summary of the Invention

[0007] To address the aforementioned problems, this application provides a flame detector structure, comprising:

[0008] The probe tube of the fire detector has a tail end connected with a wire placed in the outer passage with an outer bypass cooling gas formed by the heat shield and the afterburner casing, and its head passes through the heat shield and is placed inside the inner passage with a flame on the inside side of the heat shield.

[0009] The cavity stabilizer has a radially inwardly recessed cavity formed of metal, and the bottom of the cavity has a through hole that prevents the probe head of the fire detector from contacting the inserted part. The cavity stabilizer is connected to a wire.

[0010] The fire detector sealing seat includes a sleeve and an installation edge formed by radially outward extension of the sleeve end face edge. The sleeve is fitted onto the fire detector tube. The fire detector sealing seat is made of insulating material.

[0011] The fire detector support base has one end fixed to the outer surface of the bottom of the cavity stabilizer, and the other end presses and fixes the fire detector sealing base to the outer surface of the bottom of the cavity stabilizer.

[0012] Preferably, the tail end of the probe tube of the fire detector has an air inlet for introducing external cooling gas, and the head end has an air outlet for discharging external cooling gas into the cavity, with the interior being hollow to form a flow channel connecting the air inlet and the air outlet.

[0013] Preferably, the inner wall of the casing has a plurality of circumferentially distributed cooling grooves, which together with the outer surface of the probe tube of the fire detector form a cooling channel for the external cooling air to flow into the cavity.

[0014] Preferably, the fire detector support includes an annular elastic sheet, the outer ring edge of which is fixed to the outer surface of the cavity bottom of the concave stabilizer by welding.

[0015] Preferably, the air inlet is located on the windward side of the outer duct cooling air of the fire detector tube.

[0016] Preferably, the orientation of the air outlet is consistent with the flow direction of the flow field within the cavity at the location of the air outlet.

[0017] Preferably, the fire detector sealing seat is made of ceramic material.

[0018] Preferably, the cross-section of the cavity is rectangular.

[0019] Preferably, the probe tube of the fire detector is located in the middle of the concave cavity.

[0020] The advantages of this application include: 1. Enhanced thermal protection performance of the flame detector, improving the stability and reliability of the flame detector during long-term operation;

[0021] 2. Improve the utilization rate of cooling air in the outer duct, reduce the leakage of cooling air from the outer duct to the inner duct, and reduce the disturbance to the flow field inside the cavity;

[0022] 3. It can coordinate the axial relative displacement of the outer bypass casing and the heat shield due to thermal deformation during the ignition of the afterburner;

[0023] 4. The ceramic material sealing seat of the flame detector can ensure the good insulation of the metal shell of the flame detector;

[0024] 5. The air inlet of the fire detector adopts the total pressure air intake method, the cooling gas supply pressure is sufficient, and the opening direction of the air outlet is consistent with the flow direction of the flow field inside the cavity, so as to avoid the backflow of the gas inside the fire detector.

[0025] 6. The uniform petal-shaped cooling grooves of the flame detector sealing seat can provide uniform cooling air to the flame detector shell when the flame detector and the cavity stabilizer are relatively displaced, thus avoiding local overheating of the flame detector shell.

[0026] 7. The concave cavity vortex stabilizer of this application contains a concave cavity that forms a stable vortex, thereby realizing the ignition and flame stabilization functions of the afterburner and facilitating the measurement of the flame detector tube. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a preferred embodiment of the flame detector structure of this application;

[0028] Figure 2 This is an axial view of the probe tube of a fire detector according to a preferred embodiment of this application;

[0029] Figure 3 This is a side view of the probe tube of a fire detector according to a preferred embodiment of this application;

[0030] Figure 4 Schematic diagram of the airflow field inside the cavity stabilizer. Detailed Implementation

[0031] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0032] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0033] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection 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; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0034] To address the aforementioned problems, this application provides a flame detector structure, comprising:

[0035] The probe tube 1 of the fire detector has a tail end connected with a wire placed in the outer passage with outer cooling gas formed by the heat shield 6 and the afterburner casing 5, and its head passes through the heat shield 6 and is placed inside the inner passage with flame on the inner side of the heat shield 6.

[0036] The cavity stabilizer 4 has a radially inwardly recessed cavity formed of metal, and the bottom of the cavity has a through hole that prevents the head of the fire detector tube 1 from contacting the inserted part. The cavity stabilizer 4 is connected to a wire.

[0037] The fire detector sealing seat 2 includes a sleeve and an installation edge formed by radially outward extension of the edge of the sleeve end face. The sleeve is fitted onto the fire detector tube 1. The fire detector sealing seat 2 is made of insulating material; preferably, the fire detector sealing seat 2 is made of ceramic material.

[0038] The fire detector support 3 has one end fixed to the outer surface of the bottom of the cavity stabilizer 4, and the other end presses and fixes the fire detector sealing seat 2 to the outer surface of the bottom of the cavity stabilizer 4.

[0039] The technical effects of the above-mentioned technical features are as follows: the concave cavity stabilizer 4 causes the gas in the inner channel to form a vortex through the concave cavity, thereby realizing the flame stabilization function of the afterburner. When there is no flame, a low-level signal is formed between the wire of the flame detector tube 1 and the wire of the concave cavity stabilizer 4. When there is a flame, a large number of positive and negative ions are generated in the concave cavity stabilizer 4, and a closed loop is formed between the flame detector tube 1 and the metal wall of the concave cavity stabilizer 4. At this time, a high-level signal is formed between the two wires, thereby generating flame detection.

[0040] Preferably, the tail end of the probe tube 1 of the fire detector has an air inlet for introducing external cooling gas, and the head end has an air outlet for discharging external cooling gas into the cavity, and its interior is hollow to form a flow channel connecting the air inlet and the air outlet.

[0041] Preferably, the inner wall of the casing has multiple circumferentially distributed cooling grooves, which together with the outer surface of the probe tube 1 form a cooling channel for the external cooling air to flow into the cavity, such as... Figure 2 As shown, the fire detector sealing seat has a petal-shaped cooling groove, through which the outer duct cool air can provide outer duct cooling air to the fire detector shell.

[0042] The technical effect of the above-mentioned technical features is that, in order to reduce the impact of temperature on the probe tube 1 of the fire detector, the vents thereon cool the probe tube 1 of the fire detector.

[0043] Preferably, the probe support 3 includes an annular elastic sheet, the outer edge of which is fixed to the outer surface of the cavity bottom of the concave stabilizer 4 by welding, so that the probe sealing seat can be in contact with the stabilizer and the support and move relative to each other. The fixing method of the elastic sheet gives the ceramic probe sealing seat 2 a certain degree of flexibility, avoiding damage to the ceramic by rigid connection.

[0044] Preferably, the air inlet is located on the windward side of the outer duct cooling air of the fire detector tube 1.

[0045] Preferably, the orientation of the air outlet is consistent with the flow direction of the flow field within the cavity at the location of the air outlet, as shown in the attached figure. Figure 4 When the probe tube 1 of the fire detector is located in the middle of the concave cavity, the cross-section of the concave cavity is rectangular, and the air outlet faces the flow direction of the inner channel.

[0046] The advantages of this application include:

[0047] 1. Enhanced the thermal protection performance of the flame detector, improving its long-term stability and reliability;

[0048] 2. Improve the utilization rate of cooling air in the outer duct, reduce the leakage of cooling air from the outer duct to the inner duct, and reduce the disturbance to the flow field inside the cavity;

[0049] 3. It can coordinate the axial relative displacement of the outer bypass casing and the heat shield due to thermal deformation during the ignition of the afterburner;

[0050] 4. The ceramic material sealing seat of the flame detector can ensure the good insulation of the metal shell of the flame detector;

[0051] 5. The air inlet of the fire detector adopts the total pressure air intake method, the cooling gas supply pressure is sufficient, and the opening direction of the air outlet is consistent with the flow direction of the flow field inside the cavity, so as to avoid the backflow of the gas inside the fire detector.

[0052] 6. The uniform petal-shaped cooling grooves of the flame detector sealing seat can provide uniform cooling air to the flame detector shell when the flame detector and the cavity stabilizer are relatively displaced, thus avoiding local overheating of the flame detector shell.

[0053] 7. The concave cavity vortex stabilizer of this application contains a concave cavity that forms a stable vortex, thereby realizing the ignition and flame stabilization functions of the afterburner and facilitating the measurement of the flame detector tube.

[0054] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A flame detector structure, characterized in that, include: The probe tube (1) of the fire detector has a tail end connected with a wire placed in the outer passage of the heat shield (6) and the afterburner casing (5) with an outer passage of cooling gas. Its head passes through the heat shield (6) and is placed inside the heat shield (6) with an inner passage of flame. The cavity stabilizer (4) has a concave cavity formed of metal with an opening that is radially inward. The bottom of the cavity has a through hole that prevents the head of the fire detector tube (1) from contacting the insertion. The cavity stabilizer (4) is connected to a wire. The fire detector sealing seat (2) includes a sleeve and an installation edge formed by radially outward extension of the sleeve end face edge. The sleeve is fitted onto the fire detector tube (1). The fire detector sealing seat (2) is made of insulating material. The fire detector support (3) has one end fixed to the outer surface of the cavity bottom of the cavity stabilizer (4), and the other end presses and fixes the fire detector sealing seat (2) to the outer surface of the cavity bottom of the cavity stabilizer (4). The tail end of the fire detector tube (1) has an air inlet for introducing external cooling gas, and the head end has an air outlet for discharging external cooling gas into the cavity. Its interior is hollow, forming a flow channel connecting the air inlet and the air outlet. The inner wall of the casing has multiple circumferentially distributed cooling grooves, which together with the outer surface of the probe tube (1) of the fire detector form a cooling channel for the external cooling gas to flow into the cavity.

2. The flame detector structure as described in claim 1, characterized in that, The fire detector support (3) includes an annular elastic sheet, the outer ring edge of which is fixed to the outer surface of the cavity bottom of the cavity stabilizer (4) by welding.

3. The flame detector structure as described in claim 1, characterized in that, The air inlet is located on the windward side of the outer duct cooling air of the fire detector tube (1).

4. The flame detector structure as described in claim 1, characterized in that, The orientation of the air outlet is consistent with the flow direction of the flow field inside the cavity at the location of the air outlet.

5. The flame detector structure as described in claim 1, characterized in that, The fire detector sealing seat (2) is made of ceramic material.

6. The flame detector structure as described in claim 1, characterized in that, The cross-section of the cavity is rectangular.

7. The flame detector structure as described in claim 1, characterized in that, The probe tube (1) of the fire detector is located in the middle of the concave cavity.

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