Electrically excited combustion device and method based on an optically visible axisymmetric combustion chamber

Abstract

The present application relates to the electrically excited combustion device and method based on the optical visual axis symmetrical combustion chamber. The device comprises the axis symmetrical combustion chamber, the axis symmetrical combustion chamber is panoramic visual wall surface, and the axis symmetrical combustion chamber is made of insulating material;Along the axis symmetrical combustion chamber ring, a plurality of electrode needles perpendicular to the wall surface are arranged at intervals;The electrode needle selects all or part to be alternately arranged as positive and negative electrodes. The present application can record and detect the combustion process in all directions, the setting of multiple electrode needles can realize multi-position ignition, at the same time, the alternately arranged positive and negative electrodes can form a relatively uniform electric field in the combustion chamber, and the uniform electric field is conducive to promoting charge separation and movement in the combustion process, improving the effect of electric excitation, adjusting the combustion state, reducing the flame jitter and extinguishing phenomenon, and making the combustion more sufficient and stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ramjet engine, in particular to an electrically excited combustion device and method based on an optical visual axisymmetric combustion chamber. BACKGROUND

[0002] Ramjet engine is an aeroengine that utilizes the air flow entering the engine to decelerate and increase the static pressure of the air, and has the characteristics of simple structure, high efficiency and fast speed. However, the ramjet engine has the problems that the incoming flow in the combustion chamber is extremely fast, the fuel and air are not fully mixed, and the residence time of the fuel in the engine combustion chamber is extremely short, which makes it extremely difficult to ignite and stabilize the flame.

[0003] The axisymmetric combustion chamber can overcome the problem of boundary layer in the corner area, has better anti-back pressure capacity, and has smaller wet area, smaller friction resistance and smaller structural complexity, which can alleviate the above problems to a certain extent, but still has the problems of ignition failure, combustion oscillation and flame blowout.

[0004] At present, in order to solve the problems of ignition failure, combustion oscillation and flame blowout in the axisymmetric combustion chamber, spark plug discharge technology, collimated flow discharge technology and the like are usually used. In terms of the effect of the flame, the spark plug discharge technology has a small action area in the combustion chamber, and it is difficult to achieve reliable ignition under extreme conditions of supersonic incoming flow, and the installation of the spark plug in the axisymmetric combustion chamber easily causes irregular wall surface and interference to the incoming flow. The collimated flow discharge technology generates a large amount of joule heat during discharge, which seriously ablates the electrode, and has high requirements for the power supply and electrode material, and is difficult to work for a long time. In terms of discharge structure, technologies such as spark plug discharge and collimated flow discharge usually need to rely on ceramic structures to insulate the high-voltage electrode and the ground electrode, which increases the complexity of the structure. SUMMARY

[0005] Therefore, it is necessary to provide an electrically excited combustion device and method based on an optical visual axisymmetric combustion chamber to solve the problem of difficult control of non-steady combustion.

[0006] An electrically excited combustion device based on an optical visual axisymmetric combustion chamber comprises an axisymmetric combustion chamber, the axisymmetric combustion chamber is a panoramic visual wall surface, and the axisymmetric combustion chamber is made of insulating material; a plurality of electrode needles perpendicular to the wall surface are arranged along the circumferential direction of the axisymmetric combustion chamber at intervals; all or part of the electrode needles are selected to be arranged alternately as positive and negative electrodes.

[0007] One of the embodiments further comprises a fixed flange and an insulating support column; the fixed flange is two, respectively arranged at both ends of the axisymmetric combustion chamber to fix the axisymmetric combustion chamber; the insulating support column is several, each of which is arranged in a ring and fixed on the two fixed flanges at both ends; the insulating support column is arranged in a ring to form a containing space, and the axisymmetric combustion chamber is placed in the containing space.

[0008] One of the embodiments further comprises a buffer gasket; the buffer gasket is two, respectively arranged on the fixed flange and located at the connecting part of the axisymmetric combustion chamber and the fixed flange.

[0009] One of the embodiments is that a reentrant cavity flame holder is arranged in the axisymmetric combustion chamber, and the electrode needle is located near the reentrant cavity front edge axis of the reentrant cavity flame holder.

[0010] One of the embodiments is that the electrode needle is arranged in a single ring along the axisymmetric combustion chamber, and each electrode needle is arranged at equal intervals.

[0011] One of the embodiments is that the electrode needle is arranged in two rings along the axisymmetric combustion chamber; the electrode needles in each ring are arranged at equal intervals, and the electrode needles in the two rings are arranged in a staggered manner.

[0012] One of the embodiments is that the electrode needle is made of tungsten, copper or silver.

[0013] One of the embodiments is that the axisymmetric combustion chamber is made of quartz glass.

[0014] One of the embodiments is that when the electrode needle is arranged in a single ring along the axisymmetric combustion chamber, all the electrode needles are sequentially connected to the high-voltage pole and the ground pole; or a plurality of electrode needles are selected, and the selected electrode needles are sequentially connected to the high-voltage pole and the ground pole to realize polygonal electric excitation.

[0015] When the electrode needle is arranged in two rings along the axisymmetric combustion chamber, all the electrode needles in the first ring are connected to the high-voltage pole, and all the electrode needles in the second ring are connected to the ground pole; or a plurality of electrode needles in the first ring are selected and connected to the high-voltage pole, and a plurality of electrode needles in the second ring are selected and connected to the ground pole to realize multi-cross ring electric excitation.

[0016] An electric excitation combustion method based on an optical visual axisymmetric combustion chamber, the method comprising: accumulating positive charges on the high-voltage pole and negative charges on the ground pole to form an electric field.

[0017] Under the action of the electric field, the free charges in the combustion chamber move under the action of the electric field force, and an electric arc is formed between the high-voltage pole and the ground pole.

[0018] The electric arc swings randomly under the action of airflow in the combustion chamber, increases the action area of electric excitation and the surrounding environment, and ignites multiple positions in the cavity.

[0019] Compared with the prior art, the electric excitation combustion device and method based on the optical visual axis symmetric combustion chamber provided by the application have the following effects:

[0020] 1. The panoramic visual wall is used in the axis symmetric combustion chamber, which can enable the image acquisition device to record and detect the combustion process in real time from all directions, so that researchers can directly observe the combustion in the combustion chamber from all directions, thereby deeply understanding the combustion mechanism in the axis symmetric combustion chamber and providing detailed data support for the evaluation and optimization of combustion performance.

[0021] 2. The axis symmetric combustion chamber adopts an insulating material, so that it is not necessary to re-set an insulating structure for the electrode needle, the structure can be simplified, the labor cost and assembly difficulty are reduced, and maintenance and repair are facilitated; the device volume can be reduced, which is helpful to realize the miniaturization and lightweight design of the equipment.

[0022] 3. The multiple electrode needles are arranged, which can simultaneously generate electric excitation at different positions in the combustion chamber, realize multi-position ignition, and ensure flame stability during non-steady state combustion.

[0023] 4. All or part of the electrode needles are selected to be alternately arranged as positive and negative electrodes according to requirements, which can form electric excitation effects in multiple states to meet the requirements of different working conditions; at the same time, the alternately arranged positive and negative electrodes can form a relatively uniform electric field in the combustion chamber, the uniform electric field is conducive to promoting charge separation and movement in the combustion process, improving the electric excitation effect, adjusting the combustion state, reducing flame jitter and extinction, and making the combustion more sufficient and stable. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0025] Fig. 1 It is an exploded view of the electric excitation combustion device based on the optical visual axis symmetric combustion chamber in one embodiment;

[0026] Fig. 2 It is an axonometric view of the electric excitation combustion device based on the optical visual axis symmetric combustion chamber in one embodiment;

[0027] Fig. 3A cross-sectional view of an axisymmetric combustion chamber in one embodiment.

[0028] Explanation of reference numerals:

[0029] Axisymmetric combustion chamber 1, cavity stabilizer 11, electrode needle 2, fixing flange 3, insulating support column 4, buffer gasket 5.

[0030] The purposes, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0032] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indications also change accordingly.

[0033] In addition, the descriptions such as “first”, “second” and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as “first”, “second” can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of “plurality” is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0034] In the present application, unless otherwise specifically defined and limited, the terms “connection”, “fixing” and the like should be understood in a broad sense, for example, “fixing” can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection, or physical connection, or wireless communication connection; can be direct connection, or indirect connection through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] It can be understood that the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings.

[0037] Example 1

[0038] like Figs. 1 to 3 Figure 2 shows the schematic structure of an electrically excited combustion device based on an optically visible axisymmetric combustion chamber disclosed in this embodiment. The device comprises an axisymmetric combustion chamber 1, which has a panoramically visible wall surface and is made of insulating material. Several electrode needles 2 are spaced apart along the circumference of the axisymmetric combustion chamber 1, perpendicular to the wall surface. All or some of the electrode needles 2 are alternately arranged with positive and negative electrodes.

[0039] It also includes a fixing flange 3, insulating support columns 4, and a buffer gasket 5. Two fixing flanges 3 are provided, one at each end of the axisymmetric combustion chamber 1, to secure the chamber. Several insulating support columns 4 are provided, each spaced circumferentially, with each end of each insulating support column 4 fixed to two fixing flanges 3. The circumferential spacing of the insulating support columns 4 forms a receiving space within which the axisymmetric combustion chamber 1 is placed. Two buffer gaskets 5 are provided, one on each fixing flange 3, at the connection between the axisymmetric combustion chamber 1 and the fixing flange 3.

[0040] Specifically, the axisymmetric combustion chamber 1 is a cylindrical structure, within which is located a concave flame stabilizer 11. This concave flame stabilizer 11 is a concave cavity structure with a certain depth and width, primarily used to stabilize the flame during combustion. The axisymmetric combustion chamber 1 is constructed from a transparent, visible material, facilitating 360-degree observation and recording of the combustion process, as well as real-time recording and monitoring.

[0041] The axisymmetric combustion chamber 1 also has insulation performance, which can well insulate and separate the adjacent electrode pins 2, can effectively avoid the electrode interference between the electrode pins 2, and does not need to add other insulation structures, greatly simplifying the combustion chamber structure. At the same time, the insulation material helps to maintain the uniformity of the airflow field and the electric field inside the combustion chamber. The entire main body of the axisymmetric combustion chamber 1 adopts an insulation material, and compared with the traditional metal wall surface and then setting an insulation structure, the insulation isolation effect is better, which can effectively avoid the distortion of the electric field near the electrode, effectively avoid accidental discharge and realize stable and reliable discharge, so that the airflow can flow along the designed path, the mixing of fuel and air is more uniform, and the stability of combustion is improved. The axisymmetric combustion chamber 1 needs to have the performance of visibility and insulation at the same time, so materials such as quartz glass can be used for preparation, and specific selection can be made according to the situation.

[0042] A plurality of through holes are arranged on the axisymmetric combustion chamber 1, one end of the electrode pin 2 penetrates from the through hole and extends into the recessed cavity flame stabilizer 11, and the other end is located on the outer wall surface of the axisymmetric combustion chamber 1. Both ends of the electrode pin 2 protrude a certain height, protrude inward within 1 mm, and the outward protruding height can be selected from 10 mm to 20 mm.

[0043] The electrode pin 2 is a long and thin structure, and its cross section can be designed according to requirements, which can be circular, oval, or polygonal such as pentagon and hexagon. The electrode pin 2 is located near the front edge axis of the recessed cavity flame stabilizer 11, and can be set as a single circle or a double circle, and the number of each circle is set according to requirements. When set as a single circle, it is arranged in a ring around the position 5 mm-35 mm away from the front edge axis of the recessed cavity, and the electrode pin 2 is preferably set at equal intervals. When set as two circles, the first circle is arranged in a ring around the position 5 mm-25 mm away from the front edge axis of the recessed cavity; the second circle is arranged in a ring around the position 15 mm-35 mm away from the front edge axis of the recessed cavity. The two circles of electrode pins 2 are staggered, and the electrode pins 2 in each circle are preferably set at equal intervals. The electrode pin 2 can be made of tungsten, copper, silver or other materials.

[0044] In the embodiment, two circles of electrode needles 2 are provided, wherein the first circle is arranged in a ring shape at a position 10.0 mm axially away from the front edge of the cavity, the first circle is provided with eight electrode needles 2, and the included angle between adjacent two electrode needles 2 is 45°. The second circle is arranged in a ring shape at a position 17.0 mm axially away from the front edge of the cavity, the second circle is provided with eight electrode needles 2, and the included angle between adjacent two electrode needles 2 is also 45°. The electrode needles 2 of the first circle and the electrode needles 2 of the second circle are staggered and arranged in the middle, so that the included angle between adjacent electrode needles 2 of the first circle and the second circle is 22.5°. The electrode needles 2 of the first circle and the second circle protrude 2.0 mm at one end of the wall surface of the combustion chamber, and extend 2.0 mm at the other end in the flame stabilizer 11. It should be noted that the electrode needles 2 can also be provided in other numbers, and when provided in other numbers, the included angle between the electrode needles 2 will also change accordingly.

[0045] When the electrode needles 2 are arranged in a single circle along the axisymmetric combustion chamber 1, all the electrode needles 2 are sequentially connected to the high-voltage pole and the ground pole during the electrode connection; or a plurality of electrode needles 2 are selected, and the selected electrode needles 2 are sequentially connected to the high-voltage pole and the ground pole to realize polygonal electric excitation.

[0046] When the electrode needles 2 are arranged in two circles along the axisymmetric combustion chamber 1, all the electrode needles 2 of the first circle are connected to the high-voltage pole, and all the electrode needles 2 of the second circle are connected to the ground pole; or a plurality of electrode needles 2 are selected in the first circle and connected to the high-voltage pole, and a plurality of electrode needles 2 are selected in the second circle and connected to the ground pole to realize multi-cross ring electric excitation.

[0047] In the embodiment, although two circles of electrode needles 2 are provided, only a single circle or both circles can be used. When a single circle is used, eight electrode needles 2 can be selected, the included angle between adjacent electrode needles 2 is 45°, and the eight electrode needles 2 are connected in sequence one by one to realize “octagonal” electric excitation discharge. Four electrode needles 2 can also be selected, the included angle between adjacent electrode needles 2 is 90°, and the four electrode needles 2 are connected in sequence one by one to realize “quadrilateral” electric excitation discharge.

[0048] When double rings are adopted, all the electrode pins 2 in the double rings can be selected, i.e. a total of 16 electrode pins 2 are selected, the included angle between adjacent electrode pins 2 is 22.5°, then the eight electrode pins 2 in the first ring are connected with the high-voltage pole, and the eight electrode pins 2 in the second ring are connected with the ground pole, to realize the "eight-crossed ring" electric excitation discharge. Alternatively, four electrode pins 2 can be selected in each single ring, the included angle between adjacent electrode pins 2 in the single ring is 90°; a total of eight electrode pins are selected in the two rings, the included angle between adjacent electrode pins 2 is 45°, then the four electrode pins 2 in the first ring are connected with the high-voltage pole, and the four electrode pins 2 in the second ring are connected with the ground pole, to realize the "four-crossed ring" electric excitation discharge.

[0049] It can be seen that the present application can flexibly perform electrode connection according to the working condition requirements to form electric excitation effects in multiple states, can adapt to different combustion characteristics under the condition that the fuel properties change, has strong adaptability, the application scenarios are more extensive, and more accurate data can be obtained during experiments.

[0050] The fixed flange 3 is a ring structure with a certain thickness, which can be a circular ring or a polygonal ring. The inner ring diameter of the fixed flange 3 is matched with the peripheral size of the end of the axisymmetric combustion chamber 1, so as to facilitate embedding the two ends of the axisymmetric combustion chamber 1 in the inner ring.

[0051] A plurality of mounting holes are arranged between the inner ring and the outer ring of the fixed flange 3, the mounting hole positions of the two fixed flanges 3 correspond to each other, and the two ends of the insulating support column 4 are inserted into the corresponding mounting holes of the two fixed flanges 3, which together support and protect the axisymmetric combustion chamber 1. The insulating support column 4 is arranged in a ring shape to form a certain accommodating space, and the size of the accommodating space is preferably suitable for accommodating the entire main body of the axisymmetric combustion chamber 1. The fixed flange 3 is made of stainless steel or other materials.

[0052] A buffer gasket 5 is also arranged at the inner ring of the fixed flange 3, the peripheral size of the buffer gasket 5 is matched with the inner ring size of the fixed flange 3, and the inner peripheral size is matched with the peripheral size of the end of the axisymmetric combustion chamber 1. The buffer gasket 5 is placed in the inner ring of the fixed flange 3, and then the end of the axisymmetric combustion chamber 1 is placed in the buffer gasket 5, so as to avoid direct contact between the axisymmetric combustion chamber 1 and the fixed flange 3, thereby playing a buffering, damping and sealing role. The side of the buffer gasket 5 facing the axisymmetric combustion chamber 1 can also be extended to form a "brim", further avoiding direct contact between the axisymmetric combustion chamber 1 and the fixed flange 3, and forming a better buffering, damping and sealing effect.

[0053] Embodiment 2

[0054] Based on the electric excitation combustion device based on the optical visual axisymmetric combustion chamber in embodiment 1, the present embodiment discloses an electric excitation combustion method based on an optical visual axisymmetric combustion chamber, the method comprising:

[0055] The positive charges are gathered on the high-voltage pole, and the negative charges are gathered on the ground pole to form an electric field.

[0056] Under the action of the electric field, the free charges in the combustion chamber move under the action of the electric field force to form an electric arc between the high-voltage pole and the ground pole.

[0057] The electric arc swings randomly under the action of the airflow in the combustion chamber, increases the action area of the electric excitation and the surrounding environment, and ignites multiple positions in the cavity.

[0058] It can be understood that under the supersonic incoming flow at the inlet of the combustion chamber, after the power switch is turned on, the gas between the adjacent high-voltage pole and the ground pole will be broken down to form an electric arc. Under the action of the airflow in the combustion chamber, the electric arc will swing randomly, thereby increasing the action area of the electric excitation and the surrounding environment. When fuel is introduced into the combustion chamber, ignition can be achieved at multiple positions in the cavity, improving the reliability of successful ignition and achieving multiple repeatable reinforced ignitions.

[0059] The technical features of the above embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above embodiments are not described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present disclosure.

[0060] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. An electrically excited combustion device based on an optically visible axisymmetric combustion chamber, comprising an axisymmetric combustion chamber, characterized in that: The axisymmetric combustion chamber is a panoramic visible wall surface, and the axisymmetric combustion chamber is made of insulating material; A plurality of electrode needles perpendicular to the wall are arranged at intervals along the circumference of the axisymmetric combustion chamber; all or part of the electrode needles are selected to be alternately arranged as positive and negative electrodes; It also includes a fixing flange, an insulating support column and a buffer gasket; There are two fixing flanges, which are respectively arranged at both ends of the axisymmetric combustion chamber to fix the axisymmetric combustion chamber; There are a plurality of insulating support columns, each of which is circumferentially spaced apart, and both ends of the insulating support columns are respectively fixed on two fixing flanges; The insulating support columns are arranged circumferentially and spaced apart to form a receiving space, and the axisymmetric combustion chamber is placed in the receiving space; There are two buffer gaskets, each of which is provided on the fixed flange and is located at the connection portion between the axisymmetric combustion chamber and the fixed flange; A concave cavity flame stabilizer is provided in the axisymmetric combustion chamber, and the electrode needle is located near the concave cavity leading edge axis of the concave cavity flame stabilizer; The electrode needles are arranged in a single circle along the circumferential direction of the axisymmetric combustion chamber, and the electrode needles are arranged at equal intervals; or the electrode needles are arranged in two circles along the circumferential direction of the axisymmetric combustion chamber, and the electrode needles in each circle are arranged at equal intervals, and the electrode needles in the two circles are staggered; When the electrode needles are arranged in a single circle along the axially symmetrical combustion chamber, all the electrode needles are connected to the high voltage electrode and the ground electrode in sequence; or a plurality of electrode needles are selected and the selected electrode needles are connected to the high voltage electrode and the ground electrode in sequence to achieve polygonal electrical excitation; When the electrode needles are arranged in two circles along the axially symmetrical combustion chamber, all the electrode needles in the first circle are connected to the high-voltage electrode, and all the electrode needles in the second circle are connected to the ground electrode; or several electrode needles in the first circle are selected to be connected to the high-voltage electrode, and several electrode needles in the second circle are selected to be connected to the ground electrode, so as to realize multi-cross ring electrical excitation.

2. The electrically excited combustion device based on an optically visible axisymmetric combustion chamber according to claim 1, characterized in that: The electrode needle is made of tungsten, copper or silver.

3. The electrically excited combustion device based on an optically visible axisymmetric combustion chamber according to claim 1, characterized in that: The axisymmetric combustion chamber is made of quartz glass.

4. An electrically excited combustion method based on an optically visible axisymmetric combustion chamber, characterized in that: Applied to the electrically excited combustion device based on the optically visible axisymmetric combustion chamber as claimed in claim 1, the method comprises: collecting positive charges on the high voltage electrode and collecting negative charges on the ground electrode to form an electric field; Under the action of the electric field, the free charges in the axisymmetric combustion chamber move due to the force of the electric field, forming an arc between the high-voltage electrode and the ground electrode; The arc randomly swings under the action of the airflow in the axisymmetric combustion chamber, thereby increasing the interaction area between the electric excitation and the surrounding environment and igniting multiple positions in the cavity.

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