Arc heater electrode

Abstract

The present invention relates to the technical field of aerospace vehicle aerodynamic thermal ground simulation test equipment, and in particular to an arc heater electrode. The arc heater electrode includes a substrate, a cooling water channel and a high-pressure air channel; the substrate is an integrally formed cylindrical tube structure; a plurality of rib grooves are arranged between the inner wall and the outer wall of the substrate; the high-pressure air channel is divided into several sections, and each section of the high-pressure air channel includes an air inlet, an air collecting ring and a tangential air inlet; the air collecting ring is arranged in the substrate and distributed on the periphery of the cooling water channel, and the air inlet extends inward along the outer wall of the substrate and is connected to the air collecting ring; one end of the tangential air inlet is connected to the air collecting ring, and the other end is connected to the inner cavity of the substrate along the tangent direction of the inner wall of the substrate. By using the electrode inner wall air film protection method, the arc heater burning condition can be alleviated, the arc heater service life can be extended, the arc heater operation efficiency can be improved, the metal vapor impurities in the high-temperature gas in the arc heater can be reduced, and the gas purity can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of aerospace aircraft aerodynamic thermal ground simulation test device, in particular to an arc heater electrode. Background Art

[0002] Arc heaters are the core equipment for ground simulation test research on thermal protection of aerospace vehicles at home and abroad, and are an important means to solve the ground assessment of thermal protection of hypersonic vehicles such as missiles, recoverable satellites, and manned spacecraft return capsules. As the development of various types of spacecraft in my country continues to increase the demand for arc heater performance, it is necessary to further improve the performance of arc heaters.

[0003] The performance of arc heaters can be improved in two ways: one is to increase the total operating power of the arc heater, and the other is to improve the thermal efficiency of the arc heater during operation. Increasing the total operating power of the arc heater requires updating the supporting high-pressure cooling water system, high-voltage electric rectification system and other facilities, which is a huge and complicated workload and cost. Improving the thermal efficiency of the heater only requires improving the structure of the electrode in the heater, which is highly feasible.

[0004] At present, most types of arc heater electrodes adopt an inner and outer sleeve structure, with a cooling water channel arranged between the inner sleeve and the outer sleeve. This structure makes the electrode processing cycle long and the installation process complicated. In addition, a rubber sealing ring is used between the inner and outer sleeves of the electrode to seal the cooling water. When the arc heater is running, the high temperature environment inside the heater can easily cause the rubber sealing ring to carbonize and fail, resulting in water leakage in the heater and test failure. In view of the above problems, it is necessary to develop a new type of arc heater electrode to improve the thermal efficiency of the heater, simplify the electrode processing and installation process, and improve the reliability of the electrode operation. Summary of the invention

[0005] The first object of the present invention is to provide an arc heater electrode, which can solve the problem of low thermal efficiency in the prior art;

[0006] The present invention provides an arc heater electrode, which comprises a substrate, a cooling water channel and a high-pressure gas channel;

[0007] The base is an integrally formed cylindrical barrel structure;

[0008] The cooling water channel includes an inlet, a water collecting ring, a rib groove and an outlet;

[0009] A plurality of rib grooves are arranged between the inner wall and the outer wall of the base, and the rib grooves are arranged along the axis direction of the base;

[0010] A water collecting ring is respectively arranged at both ends of the base, one end of the rib groove is connected to one of the water collecting rings, and the other end of the rib groove is connected to the other water collecting ring;

[0011] One of the two water collecting rings is connected to the inlet, and the other is connected to the outlet;

[0012] The high-pressure air passage is divided into several sections, each section of which includes an air inlet, an air collecting ring and a tangential air inlet;

[0013] The air collecting ring is arranged in the base and distributed on the periphery of the cooling water channel. The air inlet hole extends inward along the outer wall of the base and is connected with the air collecting ring. One end of the tangential air inlet hole is connected with the air collecting ring, and the other end is connected with the inner cavity of the base along the tangent direction of the inner wall of the base.

[0014] Preferably, the substrate is provided with a plurality of inlets, and the plurality of inlets are evenly distributed along the circumference of the substrate;

[0015] The inlet is arranged on the outer wall surface of the base body, and the inlet extends inwardly from the outer wall surface along the radial direction of the base body and is communicated with the water collecting ring.

[0016] Preferably, the substrate is provided with a plurality of outlets, the plurality of outlets are evenly distributed along the circumference of the substrate, and the number of the outlets is greater than the number of the inlets.

[0017] Preferably, the distance between the rib groove and the inner wall of the base is not greater than 1 mm, and the equivalent diameter of the cooling water channel is not less than 3 mm.

[0018] Preferably, the air inlet hole extends from the outer wall of the base body to the inner side of the base body in a radial direction and is connected to the air collecting ring;

[0019] The gas collecting ring is in the shape of a ring, and is arranged concentrically with the base body and between the inner cavity and the outer wall of the base body;

[0020] Each gas collecting ring is connected to a plurality of tangential air inlet holes, and the plurality of tangential air inlet holes are evenly distributed along the circumference of the base body.

[0021] Preferably, the direction in which the tangential air inlet holes inlet air into the inner cavity of the substrate is consistent with the direction in which the arc rotates in the substrate.

[0022] Preferably, the tangential air inlet uses a Laval nozzle profile;

[0023] A throat with a minimum cross-section is formed in the middle of the tangential air inlet hole, and the diameter of the throat is less than or equal to 1 mm; the number of the tangential air inlet holes in each section of the high-pressure air duct is not less than 4.

[0024] Preferably, each section of the high-pressure air passage comprises at least one air inlet hole;

[0025] When there are multiple air inlet holes, the multiple air inlet holes are evenly distributed along the circumference of the substrate;

[0026] The sum of the cross-sectional areas of all the air inlet holes of each section of the high-pressure air duct should be equal to the cross-sectional area of ​​the air collecting ring and should be greater than the sum of the throat cross-sectional areas of all the tangential air inlet holes.

[0027] Preferably, the gas in the high-pressure air duct is high-pressure cold air, and the gas composition of the high-pressure cold air is the same as the main working gas in the matrix.

[0028] Preferably, the substrate is processed and integrally formed using metal 3D printing additive manufacturing technology.

[0029] Beneficial effects: By using the electrode inner wall air film protection method, the arc heater burning condition can be alleviated, the arc heater service life can be extended, the arc heater operating efficiency can be improved, the metal vapor impurities in the high-temperature gas in the arc heater can be reduced, and the gas purity can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A cross-sectional view of an electrode provided for a specific embodiment of the present invention;

[0032] Figure 2 A schematic diagram of an arc heater inner wall air film protection method provided by a specific embodiment of the present invention;

[0033] Figure 3 A schematic diagram of the working method of the air film protection of the inner wall of an arc heater provided in a specific embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 1: base; 2: cooling water channel; 3: high pressure air channel;

[0036] 21: inlet; 22: water collecting ring; 23: rib groove; 24: outlet;

[0037] 31: air inlet; 32: air collecting ring; 33: tangential air inlet; 34: high-pressure cooling air. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than 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.

[0039] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing 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 should not be understood as limiting the present invention.

[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. 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, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] like Figures 1 to 3 As shown, in this embodiment, an arc heater electrode is provided, which includes a substrate 1, a cooling water channel 2 and a high-pressure gas channel 3.

[0042] The base body 1 is an integrally formed cylindrical tube structure.

[0043] The cooling water channel 2 includes an inlet 21 , a water collecting ring 22 , a rib groove 23 and an outlet 24 .

[0044] A plurality of rib grooves 23 are arranged between the inner wall and the outer wall of the base body 1 , and the rib grooves 23 are arranged along the axial direction of the base body 1 .

[0045] A water collecting ring 22 is respectively provided at both ends of the base body 1 , one end of the rib groove 23 is communicated with one of the water collecting rings 22 , and the other end of the rib groove 23 is communicated with the other water collecting ring 22 .

[0046] One of the two water collecting rings 22 is communicated with the inlet 21 , and the other is communicated with the outlet 24 .

[0047] The high-pressure air passage 3 is divided into several sections, and each section of the high-pressure air passage 3 includes an air inlet 31 , an air collecting ring 32 and a tangential air inlet 33 .

[0048] The air collecting ring 32 is arranged in the base 1 and distributed around the cooling water channel 2. The air inlet 31 extends inward along the outer wall of the base 1 and communicates with the air collecting ring 32. One end of the tangential air inlet 33 communicates with the air collecting ring 32, and the other end communicates with the inner cavity of the base 1 along the tangent direction of the inner wall of the base 1.

[0049] When the arc heater is in operation, the high-voltage arc is in the inner cavity of the electrode substrate 1, and the high-voltage arc is used to heat the high-pressure airflow in the inner cavity of the substrate 1 to a high temperature state. The cooling water cools the electrode through the cooling water channel 2. The arc root falls somewhere on the inner wall of the electrode and rotates at high speed to form an arc root surface. The arc position is determined by the arc voltage, and high-pressure cold air 34 is injected through the high-pressure air channel 3 located upstream of the arc root to form a cold air film near the inner wall of the substrate 1.

[0050] Specifically, when the arc heater is in operation, the main working gas of the substrate 1 moves along the axial direction of the inner cavity of the substrate 1, and the high-pressure cold air 34 is continuously injected into the several sections of high-pressure air channels 3 arranged in sequence along the axial direction of the substrate 1. The high-pressure cold air 34 enters the gas collecting ring 32 through the air inlet 31, and then enters the substrate 1 through the tangential air inlet 33, forming a continuous annular cold air film along the inner wall of the substrate 1. Cooling water is continuously injected from the cooling water channel 2 evenly distributed outside the inner wall of the substrate 1, enters the water collecting ring 22 through the inlet 21, and then flows along the rib groove 23 and leaves the substrate 1 through the outlet 24, thereby realizing the overall protection of the electrode substrate 1.

[0051] By using the gas film protection method on the inner wall of the electrode, the arc heater burnout can be reduced, the arc heater service life can be extended, the arc heater operation efficiency can be improved, the metal vapor impurities in the high-temperature gas in the arc heater can be reduced, and the gas purity can be improved. The cooling water channel 2 and the high-pressure gas channel 3 are used to jointly protect the electrode substrate 1 as a whole, which can improve the thermal efficiency of the electrode.

[0052] The base body 1 is provided with a plurality of inlets 21 , and the plurality of inlets 21 are evenly distributed along the circumference of the base body 1 .

[0053] The inlet 21 is disposed on the outer wall surface of the base body 1 , and the inlet 21 extends inward from the outer wall surface along the radial direction of the base body 1 and communicates with the water collecting ring 22 .

[0054] The substrate 1 is provided with a plurality of outlets 24 , which are evenly distributed along the circumference of the substrate 1 , and the number of the outlets 24 is greater than the number of the inlets 21 , and the outlets 24 and the inlets 21 are not in the same longitudinal cross section of the substrate 1 .

[0055] The cooling water channel 2 adopts a rib-groove 23-type structural design, which can reduce the turbulence of water flow, reduce the flow resistance coefficient, enhance the local heat exchange efficiency at the arc root, reduce burning, and extend the life of the electrode.

[0056] The distance between the rib groove 23 and the inner wall of the substrate 1 is not greater than 1 mm, and the equivalent diameter of the cooling water channel 2 is not less than 3 mm, so as to ensure that the inner wall of the substrate 1 is sufficiently cooled.

[0057] The high-pressure gas duct 3 is designed with an arc heater inner wall gas film protection method. The arc heater inner wall gas film protection method pre-solves the following technical problems: 1. It can reduce the arc heater burnout without reducing the arc heater operating efficiency and extend the arc heater service life; 2. It can improve the arc heater operating efficiency; 3. It can reduce the metal vapor impurities in the gas in the arc heater and improve the gas purity.

[0058] The specific arrangement of the components of the high-pressure airway 3 is as follows:

[0059] The air inlet hole 31 extends from the outer wall of the base body 1 to the inner side of the base body 1 along the radial direction and is connected to the air collecting ring 32 .

[0060] The gas collecting ring 32 is in a circular ring shape, and is arranged concentrically with the base body 1 and disposed between the inner cavity and the outer wall of the base body 1 .

[0061] Each gas collecting ring 32 is connected to a plurality of tangential air inlet holes 33 , and the plurality of tangential air inlet holes 33 are evenly distributed along the circumference of the base body 1 .

[0062] The air intake direction of the tangential air inlet hole 33 into the inner cavity of the substrate 1 is consistent with the arc rotation direction in the substrate 1, so as to ensure the generation of a uniform and effective cold air protection film.

[0063] The high-pressure air channel 3 has several sections, which are evenly distributed on the periphery of the cooling water channel 2, and the sections of the high-pressure air channel 3 are separated from each other. Each section of the high-pressure air channel 3 forms a plurality of tangential air inlet holes 33 after passing through the air collecting ring 32. The tangential air inlet holes 33 pass through the gaps reserved on the rib groove 23 type cooling water channel 2 and tangentially pass into the inner cavity of the base 1 along the inner wall of the base 1.

[0064] Specifically, Figure 2As shown, when the arc heater is working, the arc column is located near the central axis of the substrate 1, and the working gas in the heater is heated by the arc to become high-temperature gas, and has both an axial speed and a rotation speed around the central axis. High-pressure cold air 34 continuously enters the gas collecting ring 32 from the air inlet 31, and enters the substrate 1 through the tangential air inlet 33, forming a cold air film on the inner wall of the heater. After the above cross-sectional structure is arranged several times along the axial direction in the substrate 1 (that is, the high-pressure air channel 3 is divided into several sections, each section of the high-pressure air channel 3 has the same structure, but is isolated from each other), a continuous cold air film can be formed to wrap the high-temperature gas therein, so that the high-temperature gas does not directly contact the inner wall of the electrode, thereby reducing the temperature of the inner wall of the electrode, reducing the burning condition of the inner wall of the electrode, and thus improving the service life of the electrode. At the same time, it also reduces the metal vapor impurities in the gas in the arc heater and improves the purity of the gas. The existence of the cold air film also reduces the heat transfer between the high-temperature working gas and the heater, reduces the heat loss on the heater structure, and thus improves the operating efficiency of the arc heater.

[0065] The tangential air inlet hole 33 uses a Laval nozzle profile, and a minimum cross-section throat is formed in the middle of the tangential air inlet hole 33, and the throat diameter is less than or equal to 1 mm, so as to ensure that the cold air protection film has sufficient strength while reducing the ratio between the cold air film and the working gas in the heater.

[0066] The number of the tangential air inlet holes 33 in each section of the high-pressure air channel 3 is not less than 4 to ensure that the cold air protection film has sufficient continuity. The specific number of the tangential air inlet holes 33 depends on the inner diameter of the substrate 1.

[0067] Each section of the high-pressure air channel 3 includes at least one air inlet hole 31. When there are multiple air inlet holes 31, the multiple air inlet holes 31 are evenly distributed along the circumference of the substrate 1. In the specific implementation process, the specific number of the air inlet holes 31 depends on the structure of the substrate 1 and the number of the tangential air inlet holes 33.

[0068] The sum of the cross-sectional areas of all the air inlet holes 31 of each section of the high-pressure air duct 3 should be equal to the cross-sectional area of ​​the air collecting ring 32 and larger than the sum of the throat cross-sectional areas of all the tangential air inlet holes 33 to ensure that an effective sound velocity section is formed at the tangential air inlet holes 33 .

[0069] The gas in the high-pressure gas channel 3 is high-pressure cold air 34 , and the gas composition of the high-pressure cold air 34 is the same as the main working gas in the substrate 1 , so as to ensure that the working gas in the substrate 1 is not mixed with impurities.

[0070] The substrate 1 is processed and integrally formed using metal 3D printing additive manufacturing technology. By using the 3D printing metal additive manufacturing process, the structure of the complex cooling water channel 2 and the high-pressure air channel 3 in the front electrode can be realized, the use of seals can be reduced, and the working reliability of the electrode can be improved;

[0071] By adopting the 3D printing metal additive manufacturing process, the integrated processing of the electrode can be achieved, thereby simplifying the electrode processing and installation, reducing the redundant volume of the front electrode cooling water channel 2 and the high-pressure air channel 3, and improving the reliability of the electrode in the working state.

[0072] To sum up, the arc heater electrode of this embodiment can effectively reduce the burning condition of the arc heater, extend the service life of the arc heater, improve the operating efficiency of the arc heater, reduce the metal vapor impurities in the gas in the arc heater, and improve the purity of the working gas.

[0073] Since the cooling water channel 2 and the high-pressure air channel 3 in the substrate 1 are staggered and isolated from each other, the electrode substrate 1 needs to be designed and processed using 3D printing metal additive manufacturing technology. Through 3D printing metal additive manufacturing, the existing inner and outer jacket type arc heater electrode can also be changed to an integrated type, shortening the processing time of the electrode, simplifying the assembly process of the electrode, and omitting the traditional sealing ring sealing method of the electrode, thereby improving the reliability of the electrode in the working state.

[0074] 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An arc heater electrode, characterized in that: Including base body, cooling water channel and high pressure air channel; The base is an integrally formed cylindrical barrel structure; The cooling water channel includes an inlet, a water collecting ring, a rib groove and an outlet; A plurality of rib grooves are arranged between the inner wall and the outer wall of the base, and the rib grooves are arranged along the axis direction of the base; A water collecting ring is respectively arranged at both ends of the base, one end of the rib groove is connected to one of the water collecting rings, and the other end of the rib groove is connected to the other water collecting ring; One of the two water collecting rings is connected to the inlet, and the other is connected to the outlet; The high-pressure air passage is divided into several sections, each section of which includes an air inlet, an air collecting ring and a tangential air inlet; The gas collecting ring is arranged in the base and distributed on the periphery of the cooling water channel. The air inlet hole extends inward along the outer wall of the base and is connected to the gas collecting ring. One end of the tangential air inlet hole is connected to the gas collecting ring, and the other end is connected to the inner cavity of the base along the tangent direction of the inner wall of the base. The air inlet hole extends from the outer wall of the base to the inner side of the base in the radial direction and is connected to the air collecting ring; The gas collecting ring is in the shape of a ring, and is arranged concentrically with the base body and between the inner cavity and the outer wall of the base body; Each gas collecting ring is connected to a plurality of tangential air inlet holes, and the plurality of tangential air inlet holes are evenly distributed along the circumference of the base body; The direction of air intake from the tangential air inlet hole into the inner cavity of the substrate is consistent with the direction of rotation of the arc in the substrate; Each section of the high-pressure air passage comprises at least one air inlet hole; When there are multiple air inlet holes, the multiple air inlet holes are evenly distributed along the circumference of the substrate; The sum of the cross-sectional areas of all the air inlet holes of each section of the high-pressure air duct should be equal to the cross-sectional area of ​​the air collecting ring and should be greater than the sum of the throat cross-sectional areas of all the tangential air inlet holes.

2. The arc heater electrode according to claim 1, characterized in that The base is provided with a plurality of inlets, and the plurality of inlets are evenly distributed along the circumference of the base; The inlet is arranged on the outer wall surface of the base body, and the inlet extends inwardly from the outer wall surface along the radial direction of the base body and is communicated with the water collecting ring.

3. The arc heater electrode according to claim 2, characterized in that The base is provided with a plurality of outlets, which are evenly distributed along the circumference of the base, and the number of the outlets is greater than the number of the inlets.

4. The arc heater electrode according to claim 1, characterized in that The distance between the rib groove and the inner wall of the base is not greater than 1 mm, and the equivalent diameter of the cooling water channel is not less than 3 mm.

5. The arc heater electrode according to claim 1, characterized in that The tangential air inlet uses a Laval nozzle profile; A throat with a minimum cross-section is formed in the middle of the tangential air inlet hole, and the diameter of the throat is less than or equal to 1 mm; the number of the tangential air inlet holes in each section of the high-pressure air duct is not less than 4.

6. The arc heater electrode according to claim 1, characterized in that The gas in the high-pressure gas channel is high-pressure cold air, and the gas composition of the high-pressure cold air is the same as the main working gas in the substrate.

7. The arc heater electrode according to claim 1, characterized in that The base is processed and integrally formed by adopting metal 3D printing additive manufacturing technology.

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