CN116717812A - A rotating detonation combustion chamber based on supplementary oxygen ignition - Google Patents

Abstract

The invention discloses a rotary detonation combustor based on oxygen supplementing ignition, which comprises a rotary detonation combustor and an oxygen supplementing device. Before the rotary detonation combustion chamber ignites, oxygen is supplied into the combustion chamber through an oxygen supplementing device, an oxygen-enriched combustion promoting area is created around the spark plug, the activity of surrounding reactants is improved, the stable formation of fire nuclei is promoted, the formation of rotary detonation waves is promoted, and the ignition success rate can be improved from 0 to 100% by oxygen supplementing ignition aiming at certain working conditions. The invention only needs to additionally install the oxygen supplementing device, the complexity and the weight of the device are far smaller than those of the pre-explosion tube, the ignition success rate is far higher than that of the ignition of the spark plug, and the adaptability and the reliability of the rotary detonation combustion chamber under the complex working condition are effectively improved. The invention can be used in the technical field of detonation propulsion.

Description

A rotating detonation combustion chamber based on supplementary oxygen ignition

Technical field

The invention relates to the technical field of detonation propulsion, specifically a rotating detonation combustion chamber based on oxygen supplementary ignition.

Background technique

Rotating detonation combustion can achieve a cycle process close to isovolumetric combustion. Its thermal cycle efficiency is higher than isobaric combustion in traditional jet engines. It also has a fast heat release rate and a simple combustion chamber structure. Therefore, rotating detonation combustion has attracted widespread attention from all over the world and has become one of the research hotspots in the field of aerospace propulsion.

Usually, there are two main ways to obtain stable detonation waves in a rotating detonation combustion chamber: one is to use spark plugs, combustion wires, etc. to form an ignition source, which quickly develops into a detonation wave, thus triggering the stable self-sustaining propagation of the rotating detonation wave. Although this ignition method has a simple structure, when the reactant activity is low or the reactant flow rate is high, it is difficult to form a stable fire core and eventually trigger detonation, so the ignition success rate is low. The second is to use the pre-detonation tube to tangentially or vertically introduce the pre-formed detonation wave into the combustion chamber to directly detonate the combustible mixture in the combustion chamber, thereby achieving stable operation of the combustion chamber. Although the ignition success rate of this ignition method is much higher than that of spark plugs, the combustion chamber requires additional pre-detonation tubes and corresponding supply ignition systems, which increases the weight and complexity of the combustion chamber and is not conducive to the practical application of rotating detonation combustion chambers. .

Therefore, it is particularly important to design a simple and efficient ignition device for the rotating detonation combustion chamber. The present invention is a rotating detonation combustion chamber based on oxygen supplementary ignition, and its ignition method has both spark plug and pre-detonation tube ignition methods. The advantages of high ignition success rate and simple structure are of great significance to the practical application of rotating detonation combustion chambers.

Contents of the invention

Technical issues to be solved

Aiming at the problems that the predetonation tube structure of the current rotating detonation combustion chamber is relatively complex, the system is heavy, and the spark plug ignition success rate is low, the present invention proposes a rotating detonation combustion chamber based on oxygen supplementary ignition. Before the ignition of the rotating detonation combustion chamber, oxygen is supplied into the combustion chamber through the oxygen supply device to create an oxygen-rich combustion-promoting area around the spark plug, improve the activity of surrounding reactants, promote the stable formation of the fire core, and then promote the formation of the rotating detonation wave. For certain working conditions, supplemental oxygen ignition can increase the ignition success rate from 0 to 100%. This invention only needs to install an additional oxygen supply device, the complexity and weight of the device are much smaller than the predetonation tube, and the ignition success rate is much higher than that of spark plug ignition, effectively improving the adaptability and reliability of the rotating detonation combustion chamber under complex working conditions.

In order to achieve the above objects, the technical solutions adopted by the present invention are:

A rotating detonation combustion chamber based on oxygen supplementation ignition includes a rotating detonation combustion chamber and an oxygen supplementation device. Its characteristic is that before the ignition of the rotating detonation combustion chamber, oxygen is supplied into the combustion chamber through an oxygen supply device, creating an oxygen-rich combustion promoting area around the spark plug, increasing the activity of surrounding reactants, promoting the rapid and stable formation of the fire core, and thereby promoting the rotating detonation. The formation of shock waves. The complexity and weight of the oxygen supplementary ignition method are much smaller than those of the predetonation tube, and the ignition success rate is much higher than that of spark plug ignition, which helps to improve the adaptability and reliability of the rotating detonation combustion chamber under complex working conditions.

The installation position of the oxygen supplement device should be upstream of the spark plug, and at the same time, the angle θ formed by its circumferential position and the spark plug should not be greater than 30°, ensuring that an oxygen-rich combustion-promoting area can be formed around the spark plug. According to the actual situation, the axial position of the oxygen supply device can be adjusted, and it can be placed in the outer ring of the oxidant supply chamber or in the outer ring of the combustion chamber. When the oxygen supplement device is working, the oxygen supplement time can be controlled: under normal working conditions, you can choose to supplement oxygen first and then ignite; for complex working conditions, you can choose to extend the oxygen supplement time and ignite while oxygen supplement is in progress to further improve the ignition success rate.

The rotating detonation combustion chamber is composed of an outer ring of the oxidizer supply chamber, an inner ring of the oxidizer supply chamber, a fuel nozzle hole, a spark plug, an inner combustion column, an outer combustion ring, an outer ring of the tail nozzle and an inner column of the tail nozzle. For the hollow cylindrical combustion chamber, the inner combustion chamber column and the inner tail nozzle column can be omitted, and the inventive principle is still applicable. The oxidant enters the annular flow channel of the combustion chamber through the oxidizer annular gap and the fuel enters the annular flow channel of the combustion chamber through the fuel nozzle hole. It is fully mixed in the annular flow channel. After the spark plug is ignited, a detonation wave rotating along the circumferential direction is formed in the annular flow channel of the rotating detonation combustion chamber. The combustion products It is discharged backward at high speed through the nozzle.

The oxidant annular gap is composed of an outer ring of the oxidant supply chamber and an inner ring of the oxidant supply chamber, and the annular flow channel of the combustion chamber is composed of an outer ring of the combustion chamber and an inner column of the combustion chamber.

Beneficial effects:

The present invention adopts a rotating detonation combustion chamber based on oxygen supplementation ignition. Before the rotational detonation combustion chamber is ignited, oxygen is supplied to the combustion chamber through an oxygen supplementation device to create an oxygen-rich combustion-promoting area around the spark plug and improve peripheral reactions. In order to promote the stable formation of fire nuclei and then promote the formation of rotating detonation waves, oxygen supplementary ignition can increase the ignition success rate from 0 to 100% for certain working conditions. This invention only needs to install an additional oxygen supply device, the complexity and weight of the device are much smaller than the predetonation tube, and the ignition success rate is much higher than that of spark plug ignition, effectively improving the adaptability and reliability of the rotating detonation combustion chamber under complex working conditions. The invention can be used in the field of detonation propulsion technology.

Description of the drawings

Figure 1 is a schematic diagram of a rotating detonation combustion chamber based on oxygen supplementation ignition (the oxygen supplementation device is located in the outer ring of the oxidizer supply chamber);

Figure 2 is a schematic diagram of a rotating detonation combustion chamber based on oxygen supplementation ignition (the oxygen supplementation device is located in the outer ring of the combustion chamber);

Figure 3 is a schematic diagram of the relative position between the spark plug and the oxygen supply device;

Figure 4 shows the working sequence ①;

Figure 5 shows the working sequence ②;

Figure 6 shows the pressure waveform of the rotating detonation wave using oxygen supplementary ignition.

Among them, 1 is the oxidizer area, 2 is the inner ring of the oxidant supply chamber, 3 is the fuel area, 4 is the oxygen supplement device, 5 is the outer ring of the oxidizer supply chamber, 6 is the fuel injection hole, 7 is the spark plug, and 8 is the column in the combustion chamber. 9 is the oxygen-rich combustion promoting area, 10 is the outer ring of the combustion chamber, 11 is the reactant mixing area, 12 is the outer ring of the tail nozzle, and 13 is the inner column of the tail nozzle.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific implementation processes.

The invention is a rotating detonation combustion chamber based on oxygen supplementation ignition, which includes a rotating detonation combustion chamber and an oxygen supplementation device 4. It is characterized in that the rotating detonation combustion chamber consists of an oxidant supply cavity outer ring 5, an oxidant supply cavity inner ring 2, a fuel nozzle hole 6, a spark plug 7, an inner combustion column 8, an outer combustion ring 10, an outer ring 12 of a tail nozzle and a tail pipe. The nozzle inner column 13 is composed of. The oxidant ring seam is composed of an inner ring 2 of the oxidant supply chamber and an outer ring 5 of the oxidant supply chamber. The annular flow channel of the combustion chamber is composed of an inner combustion column 8 and an outer ring 10 of the combustion chamber. The installation position of the oxygen supply device 4 should be upstream of the spark plug 7. At the same time, the angle θ formed between its circumferential position and the spark plug 7 is not greater than 30°, ensuring that an oxygen-rich combustion promoting area 9 can be formed around the spark plug 7.

Embodiment 1: Rotating detonation combustion chamber structure Referring to Figure 1, the oxygen supply device is installed on the outer ring 5 of the oxidant supply chamber. Referring to Figure 4 for the working sequence, during the ignition operation, the oxidant, fuel supply and oxygen supply device 4 are opened at the same time. The oxidant after partial oxygen supply enters the annular flow channel of the combustion chamber through the oxidant annular gap and the fuel through the fuel nozzle hole 6, and is combustible and mixed. The gas is fully mixed in the annular flow channel, forming an oxygen-rich combustion promoting area 9 near the spark plug 7. Afterwards, the oxygen supply device 4 is closed, the spark plug 7 is ignited, and a detonation wave rotating in the circumferential direction is formed in the annular flow channel of the rotating detonation combustion chamber. The combustion products are discharged rearward at high speed through the nozzle.

For the experiment in this embodiment, air is used as the oxidant and ethylene is used as the fuel. Under the condition of an air mass flow rate of 160g/s, the spark plug 7 cannot be directly used to trigger the rotating detonation wave for any equivalence ratio; however, after using supplementary oxygen for ignition, With the help of oxygen, the spark plug 7 can be used to trigger a rotating detonation wave. The pressure waveform is shown in Figure 6, and the detonation success rate can be increased from 0 to 100%. It can be seen that the use of oxygen supplementary ignition method can greatly reduce the complexity and weight of the detonation device on the basis of ensuring the success rate of detonation, which is conducive to improving the adaptability and reliability of the rotating detonation combustion chamber under complex working conditions.

Embodiment 2: Rotating detonation combustion chamber structure Referring to Figure 2, the oxygen supply device is installed on the outer ring 10 of the combustion chamber. Referring to Figure 4 for the working sequence, during the ignition operation, the oxidant, fuel supply and oxygen supply device 4 are opened at the same time. The oxidant passes through the oxidizer annular gap and the fuel enters the annular flow channel of the combustion chamber through the fuel nozzle hole 6. The oxygen supplied by the oxygen supply device 4 It is fully mixed with the combustible mixture in the annular flow channel to form an oxygen-rich combustion-promoting area 9 near the spark plug 7. Then the oxygen supply device 4 is closed, the spark plug 7 is ignited, and a circumferentially rotating ring is formed in the annular flow channel of the rotating detonation combustion chamber. Detonation wave, combustion products are discharged backward at high speed through the nozzle.

Embodiment 3: For complex working conditions such as high speed and low temperature, the working sequence can be referred to Figure 5. The oxidizer, fuel supply and oxygen supply device 4 are turned on at the same time, and the combustible mixture is fully mixed in the annular flow channel, forming an oxygen-rich mixture near the spark plug 7 In the combustion promoting area 9, the spark plug 7 ignites while supplementing oxygen, and then the oxygen supplement device 4 is closed. This embodiment further improves the ignition success rate under complex working conditions.

The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings and specific implementation processes. However, the present invention is not limited to the above-mentioned embodiments. Those skilled in the art can make modifications to the above methods without departing from the principles of the present invention. Various changes and optimizations.

Claims (3)

1. Rotating detonation combustion chamber based on oxygen supplementation ignition, including rotating detonation combustion chamber and oxygen supplementation device. Its characteristic is that before the ignition of the rotating detonation combustion chamber, oxygen is supplied into the combustion chamber through an oxygen supply device, creating an oxygen-rich combustion promoting area around the spark plug, increasing the activity of surrounding reactants, promoting the rapid and stable formation of the fire core, and thereby promoting the rotating detonation. The formation of shock waves. The complexity and weight of the oxygen supplementary ignition method are much smaller than those of the predetonation tube, and the ignition success rate is much higher than that of spark plug ignition, which helps to improve the adaptability and reliability of the rotating detonation combustion chamber under complex working conditions. The installation position of the oxygen supply device should be upstream of the spark plug. At the same time, the angle θ formed by its circumferential position and the spark plug should not be greater than 30° to ensure that an oxygen-rich combustion-promoting area can be formed around the spark plug. According to the actual design situation, the axial position of the oxygen supplement device can be adjusted and can be placed in the outer ring of the oxidant supply chamber or the outer ring of the combustion chamber. When the oxygen supplement device is working, the oxygen supplement time is controllable. Under normal working conditions, you can choose to supplement oxygen first and then ignite; for complex working conditions, you can choose to extend the oxygen supplement time and ignite while oxygen supplement is in progress to further improve the ignition success rate. 2. The rotating detonation combustion chamber based on oxygen supplementary ignition according to claim 1, characterized in that: the rotating detonation combustion chamber consists of an inner ring of the oxidant supply chamber, an outer ring of the oxidant supply chamber, a fuel nozzle hole, a spark plug, and an inner ring in the combustion chamber. It consists of a column, an outer ring of the combustion chamber, an outer ring of the tail nozzle and an inner column of the tail nozzle; for a hollow cylindrical combustion chamber, the inner column of the combustion chamber and the inner column of the tail nozzle can be omitted, and the invention principle is still applicable. The oxidant enters the annular flow channel of the combustion chamber through the oxidizer annular gap and the fuel enters the annular flow channel of the combustion chamber through the fuel nozzle hole. It is fully mixed in the annular flow channel. After the spark plug is ignited, a detonation wave rotating along the circumferential direction is formed in the annular flow channel of the rotating detonation combustion chamber. The combustion products It is discharged backward at high speed through the nozzle. 3. The rotating detonation combustion chamber based on oxygen supplementary ignition according to claim 2, characterized in that: the oxidant annular gap is composed of an outer ring of the oxidant supply chamber and an inner ring of the oxidant supply chamber, and the annular flow channel of the combustion chamber is formed by an outer ring of the oxidant supply chamber. It consists of a ring and a column inside the combustion chamber.