CN104791828B - Flame stabilization device of supersonic speed combustion chamber - Google Patents

Abstract

The invention discloses a flame stabilization device of a supersonic speed combustion chamber. The flame stabilization device comprises a supporting plate, oxidizing agent through holes, spiral guiding grooves and fuel guiding tubes. The supporting plate is fixedly installed inside the supersonic speed combustion chamber, the oxidizing agent through holes are formed inside the supporting plate and used for conveying oxidizing agents, the spiral guiding grooves are formed in the inner walls of the oxidizing agent through holes and used for driving the oxidizing agents to spirally rotate inside the oxidizing agent through holes, and the fuel guiding tubes are arranged inside the oxidizing agent through holes and used for conveying fuel. Through forming the oxidizing agent through holes with the spiral guiding grooves inside the supporting plate, the oxidizing agents will be output clockwise and anticlockwise in a spiral rotation mode when passing through the oxidizing agent through holes; meanwhile, because the fuel guiding tubes are arranged inside the oxidizing agent through holes, the fuel will be driven by the oxidizing agents to rotate when output at an outlet, then mixing of the fuel and the oxidizing agents is effectively improved, and the combustion efficiency of the fuel is improved; in addition, by the adoption of the structure, the pressure loss at the mixing position of the fuel and the oxidizing agents is small, and flame stability can be effectively guaranteed.

Description

A supersonic combustion chamber flame stabilization device

technical field

The present invention relates to a supersonic combustion chamber, and more specifically relates to a flame stabilizing device for a supersonic combustion chamber.

Background technique

The premise of fuel combustion is that the fuel and oxidant are mixed at the molecular weight level, and in some high-speed combustion devices, such as supersonic combustion chambers, the airflow velocity is very fast, and the residence time of the airflow in the combustion chamber is very short, so the fuel and oxidant often Adequate mixing is difficult to occur, which greatly affects the efficiency of fuel combustion.

In order to improve the combustion efficiency of fuel, scholars from various countries have done a lot of research on the mixing of fuel and oxidant in supersonic combustors. Studies have shown that there are a large number of large-scale vortices in the fuel-oxidant mixing layer of the supersonic combustor, and when these vortices are accelerated, small vortex shock waves will be formed. The small vortex shock wave will reduce the turbulence scale and generate the reverse vortex, which greatly affects the mixing of fuel and oxidant in the turbulent flow. Therefore, in order to enhance the mixing of fuel and oxidant, it is often necessary to use other methods to generate vortices, to draw oxidant into the core of the fuel flow, to increase the contact area between fuel and oxidant, so that molecular diffusion can be carried out more fully.

At present, there are generally two ways to enhance the mixing of fuel and oxidant: active and passive. The active mixing enhancement method mainly uses actively controlled external disturbances to excite unstable waves in the shear layer to generate vortices and enhance shear layer mixing. For example, an oscillating plate/line is used to introduce disturbance, and the pulse jet is used to generate sound waves of a certain frequency to excite the shear layer. However, the realization of the active mixing enhancement technology is relatively complicated, and an additional control device is required, which will affect the supersonic speed. The combustion chamber brings additional weight load, which greatly affects the normal use of the supersonic combustion chamber. The passive mixing enhancement method is a method commonly used at present, which generally uses a special geometric structure to enhance the mixing of fuel and oxidant.

Accompanying drawing 1 promptly provides a kind of existing flame stabilizing device of supersonic combustion chamber, and this device is provided with interlaced lobe-type structure 02 at the trailing edge of support plate 01, guides the incoming flow of air to mix with fuel like this. Although this existing structure can improve the mixing of fuel and oxidant to a certain extent, when this structure is adopted, the flow direction vortex and shock wave generated by the trailing edge of the support plate 01 will bring obvious total pressure loss, so huge affect the stability of the flame.

To sum up, how to provide a supersonic combustion chamber flame stabilization device that can enhance the mixing of fuel and oxidant, improve fuel combustion efficiency, and ensure flame stability has become an urgent problem to be solved by those skilled in the art.

Contents of the invention

The technical problem to be solved by the present invention is to provide a flame stabilizing device for a supersonic combustion chamber. Through its structural design, the flame stabilizing device for a supersonic combustion chamber can not only enhance the mixing of fuel and oxidant, improve the combustion efficiency of fuel, but also ensure flame stability.

A supersonic combustor flame stabilization device, comprising:

a support plate installed and fixed inside the supersonic combustion chamber;

An oxidant through hole is arranged inside the support plate for the transmission of the oxidant;

The spiral guide groove is arranged on the inner wall of the oxidant through hole, and is used to drive the oxidant to spirally rotate in the oxidant through hole;

The fuel conduit is arranged inside the oxidant through hole and is used for fuel transmission.

Preferably, the support plate is a wedge-shaped support plate.

In order to further enhance the mixing of the oxidizer and the fuel, preferably, the oxidant through hole is arranged concentrically with the fuel conduit.

Preferably, a reverse spiral guide groove is provided in the fuel conduit, and the reverse spiral guide groove is used to drive the fuel to spirally rotate in the fuel conduit, and make the fuel rotate in a direction opposite to that of the oxidizer.

Preferably, at least two oxidant through holes are provided on the support plate.

Preferably, the inner diameter ratio of the oxidizer through hole to the fuel conduit is not less than 1.25.

The beneficial effects of the present invention are: the supersonic combustion chamber flame stabilization device is provided with an oxidant through hole with a spiral guide groove in the support plate, so that the oxidant will spirally rotate counterclockwise or clockwise when passing through the oxidizer through hole, and at the same time, due to the fuel The conduit is set inside the oxidant through hole, so when the fuel is output at the outlet, it will be rotated by the oxidant, thereby effectively enhancing the mixing of the fuel and the oxidant and improving the combustion efficiency of the fuel; The pressure loss is small, which can effectively ensure the flame stability.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

Fig. 1 is the structural representation of a kind of flame stabilizing device of prior art;

Fig. 2 is the overall structure schematic diagram of embodiment 1 supersonic combustion chamber flame stabilization device;

Fig. 3 is the right side view of the supersonic combustion chamber flame stabilization device of embodiment 1;

Fig. 4 is the plan view of embodiment 1 supersonic combustion chamber flame stabilization device;

Fig. 5 is the left view of embodiment 1 supersonic combustion chamber flame stabilization device;

Fig. 6 is the front view of the supersonic combustion chamber flame stabilization device of embodiment 1;

Fig. 7 is the B-B cross-sectional view of the supersonic combustion chamber flame stabilization device of embodiment 1;

FIG. 8 is a schematic structural diagram of Embodiment 2.

detailed description

In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described The embodiments are only some of the embodiments of the present application, but not all of them.

Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

Example 1:

As shown in accompanying drawings 2 to 7, accompanying drawings 2 to 7 provide a specific embodiment of a supersonic combustion chamber flame stabilization device.

The flame stabilizing device of the supersonic combustion chamber includes: a support plate 1 installed and fixed inside the supersonic combustion chamber.

The oxidant through-holes 2 are arranged inside the support plate 1 for the transmission of the oxidant. The number of the oxidant through-holes 2 can be specifically selected according to the needs. In this embodiment, three parallel oxidant through-holes 2 are provided. One end of the oxidant through hole 2 is an air inlet for the input of oxidant; It is arranged on the rear edge of the support plate 1.

The spiral guide groove 3 is arranged on the inner wall of the oxidant through hole 2, and is used to drive the oxidant to spirally rotate in the oxidant through hole 2. Specifically, when the spiral guide groove 3 is set clockwise, the oxidant rotates clockwise in the oxidant through hole 2 , when the spiral guide groove 3 is set counterclockwise, the oxidant rotates counterclockwise in the oxidant through hole 2 . For the specific structure of the spiral guide groove 3, other methods can also be adopted, as long as it can drive the oxidant to spirally rotate.

The fuel conduit 4 is arranged inside the oxidizer through hole 2 and is used for fuel transmission. The fuel conduit 4 includes a fuel inlet and a fuel outlet, which are respectively used for the entry and exit of fuel. In this embodiment, the fuel inlet is arranged on the side of the support plate 1, and the fuel outlet is arranged on the rear edge of the support plate 1, so that the oxidant and fuel are transported to the support plate 1 phase mixing at the trailing edge.

During specific implementation, the oxidant is input into the oxidant through hole 2, such as incoming air, and the incoming air will spirally rotate and pass through the oxidant through hole 2 under the action of the spiral guide groove 3. When the air port is output, it will be mixed with the fuel output from the fuel port of the fuel conduit 4. Since the air is rotating at a high speed at this time, the air will drive the fuel to rotate together, thereby effectively enhancing the mixing of fuel and air and improving the fuel efficiency. Combustion efficiency; In addition, when this structure is adopted, the fuel and air will not be blocked by other structures at the mixing place, so the pressure loss is small and the flame stability can be effectively guaranteed.

In this embodiment, the support plate 1 is preferably a wedge-shaped support plate. In this way, the structure is relatively simple, and the use and processing are relatively convenient. Of course, in actual operation, other structural forms of the support plate 1 can also be used, as long as they can meet the design requirements.

In this embodiment, in order to further enhance the mixing of the oxidizer and the fuel, the oxidant through hole 2 and the fuel conduit 4 are concentrically arranged. In this way, when the fuel is output from the fuel outlet of the fuel conduit 4, the rotational torque on the surroundings of the fuel is basically equal, so that the mixing of the oxidizer and the fuel can be further strengthened, and the mixing ratio of the oxidizer and the fuel in different regions can be prevented from being too different.

In this embodiment, a reverse spiral guide groove 5 is provided in the fuel conduit 4, and the reverse spiral guide groove 5 is used to drive the fuel to spirally rotate in the fuel conduit 4, and make the fuel rotate in the opposite direction to the oxidizer, so , the fuel and the oxidant will intersect at the outlet of the trailing edge of the support plate 1, which is more conducive to the mixing of the oxidizer and the fuel.

Considering that the complete combustion of the fuel requires at least a certain mixing ratio between the oxidizer and the fuel, the inner diameter ratio of the oxidant through hole 2 to the fuel conduit 4 is not less than 1.25. In this embodiment, the inner diameter of the fuel conduit 4 is 1 mm, the inner diameter of the oxidant through hole 2 is 1.25 mm, and the oxidant through hole 2 is concentrically arranged with the fuel conduit 4 .

On the whole, the supersonic combustion chamber flame stabilization device provided by the present invention does not add an additional injection device, and directly utilizes the supersonic oxidant gas flow to achieve enhanced mixing effect. The solution is to use the counterclockwise or clockwise oxidant airflow to drive the fuel to rotate, enhance the mixing effect of the fuel and the oxidant, and improve the combustion efficiency. In addition, the pressure loss where the oxidizer and fuel are mixed is small, which can effectively ensure flame stability.

Example 2:

The present invention also provides a specific embodiment of the supersonic combustion chamber flame stabilization device in use, wherein, Fig. 8 is a schematic structural diagram of the device of the present invention installed in the flow channel for use.

As shown in Figure 8, the height of the flow channel provided by this embodiment is 50 mm, the upper and lower parts of the front section of the flow channel are parallel, and the upper surface of the flow channel at a distance of 23 mm from the front edge of the support plate expands outward by 3°, and the support plate 1 is arranged in the height direction of the flow channel In the middle position, the support plate 1 used in this embodiment is a wedge-shaped support plate, the total length of the wedge-shaped support plate is 32 mm, the distance from the front edge of the wedge-shaped support plate to the fuel conduit 4 is 23 mm, and the angle between the upper surface and the lower surface of the wedge-shaped support plate is 12° .

During specific implementation, air is input into the oxidant through hole 2, and the air velocity Ma=2. Among them, Ma represents the Mach number, Ma=v/c, which is the ratio of the speed v of a certain point in the flow field to the local speed of sound c at that point, that is, Ma is a number representing the multiple of the speed of sound, which is generally called the Mach number in physics , is a dimensionless number, one Mach is double the speed of sound, and two Mach is double the speed of sound. That is to say, the flow velocity of the air input into the oxidant through hole 2 in this embodiment is twice the speed of sound.

In this embodiment, at the same time, hydrogen is input into the fuel conduit 4 as fuel, and the hydrogen flow rate Ma=1, that is, the hydrogen flow rate is double the speed of sound. The comparison of the mixing effect of oxidant and fuel obtained in the specific implementation is shown in Table 1:

Among them, the first column of Table 1 is the measurement distance. In this embodiment, a total of 5 points have been measured for data comparison. For the mixing efficiency of oxidant and fuel when using traditional device, the 3rd column is the mixing efficiency of oxidant and fuel when using the device of the present invention.

Table 1

It can be seen from Table 1 that:

When the distance from the rear edge of the support plate is 0.01m, the mixing efficiency of the traditional device is 0.053456, and the mixing efficiency of the device of the present invention is 0.323552;

When the distance from the rear edge of the support plate is 0.02m, the mixing efficiency of the traditional device is 0.059342, and the mixing efficiency of the device of the present invention is 0.306254;

When the distance from the rear edge of the support plate is 0.03m, the mixing efficiency of the traditional device is 0.076458, and the mixing efficiency of the device of the present invention is 0.294953;

When the distance from the rear edge of the support plate is 0.04m, the mixing efficiency of the traditional device is 0.12458, and the mixing efficiency of the device of the present invention is 0.278473;

When the distance from the rear edge of the support plate is 0.05m, the mixing efficiency of the traditional device is 0.212533, and the mixing efficiency of the device of the present invention is 0.285114.

It can be clearly seen from the above data analysis that the mixing efficiency of the oxidizer and the fuel is greatly improved after using the device of the present invention.

The flame stabilization device for a supersonic combustion chamber provided by the present invention has been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (6)

1. A supersonic combustion chamber flame stabilization device, comprising: a support plate installed and fixed inside the supersonic combustion chamber; The oxidant through hole is arranged inside the support plate for the transmission of oxidant; it is characterized in that, The spiral guide groove is arranged on the inner wall of the oxidant through hole, and is used to drive the oxidant to spirally rotate in the oxidant through hole; The fuel conduit is arranged inside the oxidant through hole and is used for fuel transmission. 2. The flame stabilizing device for a supersonic combustion chamber according to claim 1, wherein the support plate is a wedge-shaped support plate. 3. The flame stabilizing device for a supersonic combustor according to claim 1, characterized in that, the oxidizer through hole is arranged concentrically with the fuel conduit. 4. The supersonic combustion chamber flame stabilizing device according to claim 1, wherein a reverse spiral guide groove is arranged in the fuel conduit, and the reverse spiral guide groove is used to drive fuel to flow in the fuel conduit The inner helix rotates and rotates the fuel in the opposite direction to the oxidizer. 5. The flame stabilizing device for a supersonic combustor according to claim 1, characterized in that at least two oxidant through-holes are arranged on the support plate. 6. The flame stabilization device for a supersonic combustor according to claim 1, characterized in that the inner diameter ratio of the oxidant through hole to the fuel conduit is not less than 1.25.