CN104895698A - Boosting structure of large-pipe-diameter pulse detonation rocket engine and control method thereof - Google Patents

Abstract

The invention proposes a propulsion structure and a control method of a large-diameter pulse detonation rocket engine, including an oxygen, fuel and isolation gas supply system and a control method of a partitioned detonation tube. The oxygen supply system includes a high-pressure gas cylinder, a shut-off valve, a pressure-reducing valve, a solenoid valve and a thin hollow tube full of small holes in the circumference; the isolated gas supply system includes a high-pressure gas cylinder, a shut-off valve, a pressure-reducing valve, a solenoid valve and Four-way air intake; the fuel supply system includes a squeeze cylinder, a pressure reducing valve, an oil bottle, an oil valve and a hollow outer wall cavity of a detonation tube with fuel injection holes. By controlling the pressure reducing valve, the diameter of the small hole on the hollow thin tube and the diameter of the fuel injection hole, the supply pressure, equivalence ratio and filling condition of fuel and oxidant are controlled within an appropriate range, and the detonation tube can be detonated in a partitioned detonation tube. Obtain continuous and stable detonation waves. The propulsion structure and control method of the large-diameter pulse detonation rocket engine proposed by the present invention are of great significance to the future development of the pulse detonation engine, which can effectively simplify the structure of the engine, improve its filling condition, and increase the average thrust.

Description

Propulsion structure and control method of a large-diameter pulse detonation rocket engine

technical field

The invention relates to the technical field of pulse detonation engines, and relates to a propulsion structure of a large-diameter pulse detonation rocket engine and a control method thereof.

Background technique

Pulse Detonation Rocket Engine (PDRE for short) is a new concept engine that uses intermittent detonation waves to generate thrust. As a new type of power plant, PDRE has a good application prospect due to its potential advantages such as simple structure, high cycle efficiency, wide working range and high thrust-to-weight ratio. In recent years, a lot of research work has been done to improve the performance of pulse detonation engines at home and abroad, and great progress has been made.

Compared with the existing propulsion system, PDRE seems to have great potential advantages, but there are still many problems and challenges to realize these potential advantages, one of the key problems is how to increase its thrust to The degree to which it can be put into engineering practice. There are many factors affecting the thrust of PDRE, and among them, the diameter of the PDRE detonation tube is the main factor determining its thrust. However, when the diameter of the detonation tube increases to a certain extent, the detonation wave will be difficult to detonate normally. and self-sustaining. In order to solve this problem, most research teams in the world are currently using multi-tube PDRE, which increases the thrust by increasing the number of detonation tubes. This method is certainly feasible, but the multi-tube PDRE will take up a lot of volume, and will increase the self-weight of the PDRE a lot, which will cause a great burden on the PDRE.

At present, the fuel and oxidant supply methods of most PDREs are head supply, which makes the overall structure of PDRE more concise and clear, but this supply method also has major defects. When the working frequency of PDRE is high, the simple head supply cannot quickly fill the entire detonation tube with oxidant and fuel within the filling time of one cycle, which will cause the filling of the detonation tube to be too low, thus affecting Knock effect and steady work of PDRE. In order to solve this problem, some research institutes have proposed a distributed supply of fuel and oxidant to fill the entire detonation tube more fully.

Contents of the invention

technical problem to be solved

Increasing the operating frequency of the pulse detonation engine and enlarging the diameter of the detonation tube are two main ways to increase its average thrust. In order to solve the two problems that the detonation wave is difficult to detonate normally and be self-sustaining under the condition of large pipe diameter, and the filling of the detonation tube is too low under the condition of high frequency operation, the invention proposes the use of partitioned detonation tubes, and uses fuel and oxidant distributed supply. By using the detonation tube designed in the present invention and following correct operation steps, the high-frequency operation of the large-diameter pulse detonation engine can be successfully realized.

Technical scheme of the present invention is:

A propulsion structure and control method for a large-diameter pulse detonation rocket engine, including a fuel supply system, an oxygen supply system, an isolated gas supply system, and a partitioned detonation tube device, characterized in that: a large-diameter The detonation tube is divided into four sub-pipes of the same size. A hollow pipe is passed into the center of the detonation tube as an oxygen supply system, and a hole is punched in the center of each sub-pipe at the head of the detonation tube as an isolation gas. The supply system of the detonation tube uses fuel as the fuel supply system in the hollow outer wall cavity of the detonation tube, and installs one igniter in each branch of the detonation tube.

The propulsion structure and control method of the large-diameter pulse detonation rocket engine is characterized in that a large-diameter detonation tube that is difficult to detonate is divided into four fan-shaped detonation tubes of the same size, which solves the problem of detonation. The detonation wave caused by too large pipe diameter is difficult to detonate and self-sustaining.

The propulsion structure and control method of a large-diameter pulse detonation rocket engine is characterized in that: a hollow thin tube full of small holes is used in the circumferential direction, and an electromagnetic valve is installed on its head to serve as oxygen The supply system improves the traditional axial direct air supply to distributed air supply along the circumference of the thin tube. This feature will make the filling of oxygen more uniform and sufficient. At the same time, this structure similar to divergent cooling is also It will have a certain cooling effect on the pipe wall.

The propulsion structure of a large-diameter pulse detonation rocket engine and its control method are characterized in that: a hole is punched at the center of the wall surface of the head of each separated individual detonation tube, and a hole is made at the head of the detonation tube. A solenoid valve is installed at the end, and the axial inlet of the isolation gas blows off the exhaust gas after combustion.

The propulsion structure of a large-diameter pulse detonation rocket engine and its control method are characterized in that fuel is injected into the cavity on the outer wall of the detonation tube, and the inner wall of the outer wall of each individual detonation tube Drill a row of fuel injection holes along the axial direction at an interval of 100mm, and the direction of the holes is perpendicular to the axial direction and inward. An oil valve is installed outside the oil chamber of the detonation tube to control the filling of fuel, thereby forming the fuel supply system of the entire detonation tube. This system first realizes the distributed supply of fuel, making the filling of fuel more uniform and sufficient; secondly, the injected fuel can cool the wall surface of the high-temperature detonation tube, and the preheated fuel is sprayed into the detonation tube. It is also easier to detonate, thereby realizing the regenerative cooling of the fuel; again, the injected fuel can form a fluid barrier, accelerate the formation of the detonation wave, and shorten the distance of the DDT (Deflagration to Detonation Transition) section.

Beneficial effect

Using the high-efficiency propulsion structure and control method of the large-diameter pulse detonation rocket engine provided by the present invention, a large-diameter detonation tube is divided into four detonation tubes of the same size, which can solve the problem of large-diameter detonation The tube is difficult to detonate, and, compared with the multi-tube pulse detonation engine, this method greatly reduces the volume and weight of the pulse detonation engine. The fuel and oxidant distributed supply mode adopted in the present invention has a simple structure, saves space, and can successfully solve the problem of insufficient filling degree caused by the single head supply under the high-frequency working state of the PDRE. At the same time, the fuel supply method of the present invention successfully realizes the regenerative cooling of the fuel, forms a fluid barrier, and accelerates the formation of detonation waves.

Description of drawings

Figure 1: Schematic diagram of the system of the present invention

Figure 2: Schematic diagram of the head section of the detonation tube

Figure 3: In a working cycle, the control timing diagram of the solenoid valve and the igniter

Among them, 1-1 is the oxidant gas cylinder, 1-2 is the oxidant shut-off valve, 1-3 is the oxidant pressure reducing valve, 1-4 is the oxidant inlet solenoid valve, 1-5 is the oxidant supply hollow filled with small holes in the circumferential direction. Pipeline; 2-1 is the isolation gas cylinder, 2-2 is the isolation gas stop valve, 2-3 is the isolation gas pressure reducing valve, 2-4 is the isolation gas inlet solenoid valve, 2-51, 2-52, 2- 53, 2-54 are the four inlets of the isolation gas at the head of the detonation tube; 3-1, 3-2, 3-3, 3-4 are the four igniters around the detonation tube; 4-1 is the Liquid fuel bottle, 4-2 is the liquid fuel cut-off valve, 4-3 is the liquid fuel inlet electromagnetic valve, 4-4 is the hollow outer wall cavity of the detonation tube leading into the liquid fuel, 4-5 is the fuel injection valve perpendicular to the axial direction Note the small hole; 5-1 is the fuel extrusion gas cylinder, 5-2 is the fuel extrusion gas pressure reducing valve; 6-1, 6-2, 6-3, 6-4 are the large-diameter detonation tube Divide into quarters.

Detailed ways

Below in conjunction with specific example and accompanying drawing, the present invention will be further described

The control device of the partitioned pulse detonation engine in this embodiment includes an isolation gas supply system, an oxygen supply system and a fuel supply system.

The isolation gas supply system consists of an isolation gas cylinder 2-1, an isolation gas shut-off valve 2-2, an isolation gas pressure reducing valve 2-3, an isolation gas inlet solenoid valve 2-4 and four isolation gas inlets at the head of the detonation tube 2-5 composition.

The oxygen supply system is composed of an oxidant gas cylinder 1-1, an oxidant shut-off valve 1-2, an oxidant pressure reducing valve 1-3, an oxidant inlet solenoid valve 1-4 and an oxidant supply hollow pipe 1-5 covered with small holes in the circumferential direction.

The fuel supply system consists of a squeeze gas cylinder 5-1, a squeeze gas pressure reducing valve 5-2, a liquid fuel bottle 4-1, a liquid fuel shut-off valve 4-2, a liquid fuel inlet solenoid valve 4-3, and a liquid fuel inlet valve 4-3. The hollow outer wall cavity 4-4 of the fuel detonation tube, and the fuel injection small hole 4-5 perpendicular to the axial direction.

In this embodiment, the fuel used is aviation kerosene, the oxidant is oxygen, the insulating gas is nitrogen, the fuel extrusion gas is nitrogen, and the igniter is an automobile spark plug. The diameter of the small hole for fuel injection on the hollow outer wall cavity of the detonation tube is 0.2-0.5 mm, the diameter of the small hole on the hollow pipe responsible for oxidant supply is 0.5-2 mm, and the diameter of the isolation gas inlet at the head of the detonation tube is 10 mm. Four pressure sensors are installed equidistantly in the detonation propagation section of each separated detonation tube to measure the pressure of each detonation tube respectively.

In this embodiment, the pressure of the oxidant and the isolation gas after passing through the pressure reducing valve are 1.5MPa and 0.6MPa respectively, the pressure of the fuel extrusion gas after passing through the pressure reducing valve is 0.5MPa, and the ambient pressure and temperature are 0.101325MPa and 288K respectively, In this case, the equivalent ratio of aviation kerosene to oxygen is approximately 1.0. Under such conditions, the pressure and velocity of the detonation wave can be calculated to be 4.078MPa and 2302m/s, respectively, through the commonly used detonation calculation software CEA (Chemical Equilibrium and Applications).

When working, each channel needs to be supplied according to a certain control timing. As shown in Figure 3, the solenoid valve and igniter control timing diagram, within a control cycle, the solenoid valve of the oxidant supply system and the oil valve of the fuel supply system work in exactly the same state. At the beginning of each control cycle, the oxidizer and fuel solenoid valves 1-4 and 4-3 are simultaneously opened to fill the four separate detonation tubes in preparation for subsequent ignition, after which the oxidizer and fuel solenoid valves 1-4 and 4-3 are closed at the same time, use the igniter 3-1, 3-2, 3-3, 3-4 to ignite the four detonation tubes at the same time, the fuel in the detonation tube is ignited, and after the The constant evolution in the detonation tube eventually creates a detonation wave that propagates out of the tube. Subsequently, the electromagnetic valve 2-4 of the isolation gas supply system is opened, and the waste gas in the detonation tube is blown through the four isolation gas inlets 2-51, 2-52, 2-53, 2-54 at the head of the detonation tube. In addition, close the isolation gas solenoid valve 2-4 until the end of a control cycle. Taking the working frequency of 30Hz as an example, the working phase of the solenoid valve of the oxidizer and fuel supply system is 0°, and the duty cycle is 0.4; the working phase of the solenoid valve of the isolation gas supply system is 251°, and the duty cycle is 0.3; the ignition signal The working phase is 144° and the duty cycle is 0.03.

In this embodiment, the solenoid valve is used to control the working sequence of the oxidizer, the fuel and the isolation gas, and the continuous and stable operation of the partitioned pulse detonation engine can be successfully realized. At the same time, it can be judged whether a detonation wave is formed by using the curve of pressure changing with time collected by the pressure sensor installed on the detonation tube. Therefore, by adopting the method provided by the invention, continuous and stable detonation waves can be generated in the large-diameter pulse detonation rocket engine.

Claims (5)

1. A propulsion structure of a large-diameter pulse detonation rocket engine and its control method, comprising a fuel supply system, an oxygen supply system, an isolation gas supply system, and a partitioned detonation tube device, characterized in that: a large tube The diameter of the detonation tube is divided into four sub-pipes of the same size. A hollow pipe is passed into the center of the detonation tube as an oxygen supply system, and a hole is punched in the center of each sub-pipe at the head of the detonation tube as a To isolate the gas supply system, the fuel oil is introduced into the hollow outer wall cavity of the detonation tube as the fuel supply system, and one igniter is installed in each branch of the detonation tube. 2. The propulsion structure and control method of a large-diameter pulse detonation rocket engine according to claim 1, characterized in that: a large-diameter detonation tube that is difficult to detonate is divided into four sectors of the same size detonation tube. 3. The high-efficiency propulsion structure and control method of a kind of large-diameter pulse detonation rocket engine according to claim 1, it is characterized in that: use a hollow thin tube that is full of small holes in the circumferential direction, and A solenoid valve is installed in the head as an oxygen supply system, which improves the traditional axial direct air supply to distributed air supply along the circumference of the capillary. 4. The propulsion structure and control method of a large-diameter pulse detonation rocket engine according to claim 1, characterized in that: one is punched at the center of the head wall surface of each separated individual detonation tube hole, and a solenoid valve is installed at the head of the detonation tube to isolate the axial air intake of the gas and blow off the exhaust gas after combustion. 5. The propulsion structure of a large-diameter pulse detonation rocket engine and its control method according to claim 1, characterized in that: fuel oil is introduced into the cavity on the outer wall of the detonation tube, and each individual On the inner wall surface of the outer wall of the detonation tube, a row of fuel injection holes is drilled along the axial direction at an interval of 100 mm, and the direction of the holes is perpendicular to the axial direction and inward. An oil valve is installed outside the oil chamber of the detonation tube to control the filling of fuel, thereby forming the fuel supply system of the entire detonation tube. This system first realizes the distributed supply of fuel, making the filling of fuel more uniform and sufficient; secondly, the injected fuel can cool the wall surface of the high-temperature detonation tube, and the preheated fuel is sprayed into the detonation tube. It is also easier to detonate, thereby realizing the regenerative cooling of the fuel; again, the injected fuel can form a fluid barrier, accelerate the formation of the detonation wave, and shorten the distance of the DDT section.