CN105927391A - Ignition device for liquid ramjet engine - Google Patents

Abstract

The invention discloses an ignition device for a liquid ramjet engine, which comprises an igniter, an oil supply pipe, an air supply pipe, a front casing, a rear casing, an expansion pipe and a flame stabilizer, and the front casing and the rear casing are fixedly connected , the igniter is set at the connection between the front shell and the rear shell, which is convenient for the installation of the igniter. The oil supply pipe passes through the outer wall of the front shell, extends into the front shell, and is firmly connected with the igniter, and the air supply pipe passes through the front shell The outer wall extends into the front housing and is fixedly connected with the igniter, the expansion tube is fixedly connected with the igniter, and the flame stabilizer is fixedly connected with the expansion tube. The invention can ensure the formation of an inextinguishable pioneer torch in the ramjet under the condition of high-speed air flow, and the torch is used to ignite the oil-gas mixture in the main combustion chamber to make the engine work normally.

Description

Ignition device for liquid ramjet

technical field

The invention belongs to the technical field of ramjet engines, in particular to an ignition device for a liquid ramjet engine.

Background technique

A ramjet is an aeroengine with a simple structure, and its structure is generally composed of an air inlet, an ignition device, a combustion chamber, a flame stabilizer, and a nozzle. Due to the advantages of light weight and low cost, the ramjet engine is widely used as the power device for the cruising stage of the aircraft. Ignition device is an essential part set in the combustion chamber of liquid fuel ramjet engine for reliable ignition and stable combustion.

As far as the widely used spark plug igniter is concerned, its advantages are: simple equipment and high frequency; its disadvantages are: low ignition energy, only suitable for igniting gaseous fuel or atomized liquid fuel, low temperature of oil-gas mixture, The ignition area is small, and when there are pollutants between the electrodes, it is easy to cause ignition failure. When the gas flow rate is too high, it is difficult to ignite or it is easy to extinguish.

Li Qing, Pan Yu, Tan Jianguo, etc. published in the "Comparative Analysis of the Performance of Flame Stabilizers with V-groove and V-grooves in Subcombustible Ramjet Engines [J]" (Journal of Aerodynamics, 2010, 25(01):35-40.) An ignition device for a liquid ramjet engine is developed. Its working principle is to first use a spark plug to ignite a hydrogen-oxygen mixture, and then use a gas flame to ignite the fuel-gas mixture. The ignition success rate has been improved, but an additional set of hydrogen is required. The supply device greatly increases the complexity of the structure.

Contents of the invention

The purpose of the present invention is to provide an ignition device for a liquid ramjet to ensure that a pioneer torch that is not easy to extinguish is formed in the ramjet under high-speed airflow conditions, and the torch is used to ignite the oil-gas mixture in the main combustion chamber to make the engine work normally .

The technical solution for realizing the object of the present invention is: an ignition device for a liquid ramjet, characterized in that it includes an igniter, an oil supply pipe, an air supply pipe, a front casing, a rear casing, an expansion pipe and a flame stabilizer , the front shell and the rear shell are fixedly connected, the igniter is located at the junction of the front shell and the rear shell, one end of the expansion tube is set in the rear shell, and is fixedly connected with the rear end of the igniter, and the rear of the flame stabilizer and the expansion tube The end is fixedly connected, the fuel supply pipe is fixedly connected with the igniter through the front housing, and the air supply pipe is fixedly connected with the igniter through the front housing.

The igniter includes a glow plug, a fastening ring, a windproof cap and an igniter main body. The igniter main body includes a first cylinder and a second cylinder. The center of the first cylinder is provided with a second-order through hole, and the second cylinder is arranged on the first cylinder. At the rear end, the center of the rear end face of the second cylinder is provided with a first groove, and the side wall of the first cylinder of the igniter body is provided with a first through hole and a second through hole, and the first through hole and the second through hole are connected to each other. Intersecting and communicating; the opening end of the windproof cap is set in the first groove of the second cylinder, at least two third through holes are arranged in parallel on the side wall of the cap body, and a circle of second grooves is arranged on the inner wall of the front end of the fastening ring , the outer wall of the second cylinder is set in the second groove and is fixedly connected with the second groove. The second groove clamps the opening end of the windproof cap to play a fixing role. The windproof cap is on the same side as the air outlet end, and the edge of the glow plug The direction of the central axis of the igniter body is set in the second-order through hole of the igniter body; the expansion tube is fixedly connected to the rear end of the fastening ring, and the oil supply pipe and the air supply pipe extend from both ends of the first through hole, and are located at the electric heater. On both sides of the plug, two bolts pass through the front casing and extend into the second through hole, and the igniter is fixedly connected with the front casing through the above-mentioned oil supply pipe, air supply pipe and two bolts.

The gap between the heating rod of the glow plug and the inner wall of the second-order through hole is 0.2 mm to 0.4 mm.

The diameter of the first cylinder is smaller than the diameter of the second cylinder; the length of the outer wall of the second cylinder is smaller than the length of the second groove.

The expansion tube includes a circular platform tube, a first cylindrical tube and a second cylindrical tube, the first cylindrical tube and the second cylindrical tube are respectively arranged at the two ends of the circular platform tube, the first cylindrical tube is fixedly connected with the fastening ring, and the circular platform tube From front to back, there are two mutually perpendicular and communicating fourth through holes, two mutually perpendicular and communicating fifth through holes and two mutually perpendicular and communicating sixth through holes, the fourth through hole and the sixth through hole The opening directions are the same, and there is an included angle between the fifth through hole and the fourth through hole; the flame stabilizer extends from the second cylinder into the rear shell and is fixedly connected with the second cylinder.

Compared with the prior art, the present invention has the following remarkable advantages: (1) Compared with the spark plug igniter, the present invention does not need a fuel atomization device, and the ignition energy of the electric glow plug is large, and the temperature is high (the operating temperature is 1150°C). The reliability is effectively improved during the ignition process.

(2) To adapt to the condition of continuously increasing incoming flow velocity, a high ignition success rate can be ensured through the adjustment of the oil supply pipe and the air supply pipe.

(3) When the incoming flow conditions are constantly changing, by adjusting the oil inlet and air intake speeds, matching the corresponding incoming flow speeds can ensure successful ignition, and the matching of oil inlet, air intake speeds and incoming flow speeds has a large elastic range and is easy to adjust. The ignitable flow range is greatly widened.

(4) The present invention has the advantages of simple structure, low cost, high reliability and convenient processing and assembly.

Description of drawings

Fig. 1 is a structural schematic diagram of an ignition device for a liquid ramjet according to the present invention.

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

1, an ignition device for a liquid ramjet, including an igniter, an oil supply pipe 3, an air supply pipe 8, a front casing 2, a rear casing 4, an expansion pipe 9 and a flame stabilizer 10, the front casing 2 and the rear case 4 are fixedly connected by threads, and the igniter is located at the junction of the front case 2 and the rear case 4, which facilitates the installation of the igniter. One end of the expansion tube 9 is arranged in the rear case 4, and is connected to the The ends are fixed by threads, the flame stabilizer 10 and the rear end of the expansion tube 9 are connected by bolts, and the centerline of the main body of the flame stabilizer 10 coincides with the centerline of the main body of the expansion tube 9 . The oil supply pipe 3 passes through the front housing 2 and is fixedly connected with the igniter for supplying oil to the igniter, and the air supply pipe 8 passes through the front housing 2 and is fixedly connected with the igniter for supplying gas to the igniter.

The igniter includes a glow plug 1, a fastening ring 5, a windproof cap 6 and an igniter main body 7. The igniter main body 7 includes a first cylinder and a second cylinder. The center of the first cylinder is provided with a second-order through hole, and the second cylinder is arranged on the The rear end of the first cylinder and the center of the rear end surface of the second cylinder are provided with a first groove, and the side wall of the first cylinder of the igniter main body 7 is provided with a first through hole and a second through hole, the first through hole and the second through hole The two through holes intersect and communicate with each other. The opening end of the windproof cap 6 is arranged in the first groove of the second cylinder, at least two third through holes are arranged in parallel on the side wall of the cap body, and the inner wall of the front end of the fastening ring 5 is provided with a circle of second grooves. The outer walls of the two cylinders are arranged in the second groove and are fixedly connected with the second groove. The second groove clamps the opening end of the windproof cap 6 to play a fixing role. The windproof cap 6 is on the same side as the air outlet end, and the glow plug 1 It is arranged in the second-order through hole of the igniter main body 7 along the central axis of the igniter main body 7; the expansion pipe 9 and the rear end of the fastening ring 5 are fixedly connected by threads, and the oil supply pipe 3 and the air supply pipe 8 are connected through the first passage. Both ends of the hole protrude and are located on both sides of the glow plug 1. Two bolts pass through the front housing 2 and then extend into the second through hole. The igniter and the front The casing 2 is fixedly connected.

The gap between the heating rod of the glow plug 1 and the inner wall of the second-order through hole is 0.2 mm to 0.4 mm.

The diameter of the first cylinder of the igniter body 7 is smaller than the diameter of the second cylinder; the length of the outer wall of the second cylinder is less than the length of the second groove.

The expansion tube 9 includes a round platform tube, a first cylindrical tube and a second cylindrical tube. The first cylindrical tube and the second cylindrical tube are respectively arranged at the two ends of the round platform tube. The first cylindrical tube is fixedly connected with the fastening ring 5. There are two mutually perpendicular and communicating fourth through holes 9-1, two mutually perpendicular and communicating fifth through holes 9-2 and two mutually perpendicular and communicating sixth through holes 9-3 from front to back, The opening direction of the fourth through hole 9-1 and the sixth through hole 9-3 are the same, and there is an angle between the fifth through hole 9-2 and the fourth through hole 9-1; the second cylinder is provided with three sets of threaded holes, and the flame is stable The device 10 extends into the rear casing 4 from the second cylinder, and is fixedly connected with the second cylinder by bolts.

Lead wires of the glow plug 1 protrude from the wiring hole on the outer wall of the front housing 2 .

The incoming flow velocity in the expansion pipe 9 is on the low side, creating space for the smooth combustion of the oil-gas mixture.

The flame stabilizer 10 plays the role of stabilizing the flame. When the high-speed gas flame sprays out, it can effectively stabilize the flame and adapt to a higher incoming flow velocity.

Working principle: The glow plug 1 is energized and works for several seconds in advance. After reaching the operating temperature, the air flows into the ignition device from the left side of Figure 1, the fuel supply pipe 3 pumps fuel, and the air supply pipe 8 supplies air. When the fuel encounters high temperature, it immediately Gasification, mixed with the air supplied into the igniter body 7 to form an oil-air mixture, the oil-air mixture enters the windproof cap 6 after passing through the gap between the third stage boss of the glow plug 1 and the igniter body 7, and touches the extension The hot glow plug 1 end of the igniter body 7 is quickly ignited to form a premixed flame. After the flame and fuel pass through the fourth through hole, they are sprayed to the right along the cavity between the fastening ring 5 and the windshield 6. After the flame and fuel oil reach the expansion tube 9, they are mixed with the air entering through the first through hole, the second through hole and the third through hole on the first round platform of the expansion tube 9, and continue to spray to the right along with the airflow. When the incoming velocity is too high, the flame may be extinguished. At this time, the gas flame encounters the flame stabilizer 10 and the speed is reduced, and the flame is stabilized so that it can continue to burn and propagate downstream.

Claims (5)

1. An ignition device for a liquid ramjet, characterized in that it includes an igniter, an oil supply pipe (3), an air supply pipe (8), a front casing (2), a rear casing (4), and an expansion pipe (9) is fixedly connected with the flame stabilizer (10), the front housing (2) and the rear housing (4), the igniter is located at the junction of the front housing (2) and the rear housing (4), and the expansion tube ( 9) One end is set in the rear housing (4), and is fixedly connected to the rear end of the igniter, the flame stabilizer (10) is fixedly connected to the rear end of the extension tube (9), and the oil supply pipe (3) passes through the front housing (2) It is fixedly connected with the igniter, and the air supply pipe (8) passes through the front housing (2) and is fixedly connected with the igniter. 2. The ignition device for liquid ramjet according to claim 1, characterized in that: the igniter includes a glow plug (1), a fastening ring (5), a windproof cap (6) and an igniter body ( 7), the main body of the igniter (7) includes a first cylinder and a second cylinder, the center of the first cylinder is provided with a second-order through hole, the second cylinder is provided at the rear end of the first cylinder, and the center of the rear end of the second cylinder is provided with a first The groove, the first through hole and the second through hole are opened on the first cylindrical side wall of the igniter body (7), and the first through hole and the second through hole intersect and communicate with each other; the windproof cap (6) The opening end is arranged in the first groove of the second cylinder, at least two third through holes are arranged in parallel on the side wall of the hat body, and a circle of second grooves is arranged on the inner wall of the front end of the fastening ring (5). The outer wall is set in the second groove and is fixedly connected with the second groove. The second groove clamps the opening end of the windproof cap (6) to play a fixing role. The windproof cap (6) is on the same side as the air outlet end, and the electric heating The plug (1) is set in the second-order through hole of the igniter body (7) along the central axis of the igniter body (7); the expansion tube (9) is fixedly connected to the rear end of the fastening ring (5) for oil supply The pipe (3) and air supply pipe (8) protrude from both ends of the first through hole and are located on both sides of the glow plug (1). The two bolts pass through the front housing (2) and then extend into the second through hole. The above-mentioned oil supply pipe (3), air supply pipe (8) and two bolts connect the igniter with the front housing (2). 3. The ignition device for a liquid ramjet according to claim 2, characterized in that: the gap between the heating rod of the glow plug (1) and the inner wall of the second-order through hole is 0.2mm~0.4mm. 4. The ignition device for a liquid ramjet according to claim 2, characterized in that: the diameter of the first cylinder is smaller than the diameter of the second cylinder; the length of the outer wall of the second cylinder is smaller than the length of the second groove. 5. The ignition device for liquid ramjet according to claim 1, characterized in that: the expansion tube (9) includes a conical tube, a first cylindrical tube and a second cylindrical tube, the first cylindrical tube and the second cylindrical tube The cylindrical tubes are respectively arranged at both ends of the round platform tube, the first cylindrical tube is fixedly connected with the fastening ring (5), and the round platform tube is provided with two mutually perpendicular and connected fourth through holes (9-1) from front to back, Two fifth through holes (9-2) perpendicular to each other and connected to each other, two sixth through holes (9-3) perpendicular to each other and connected to each other, the fourth through hole (9-1) and the sixth through hole (9-1) -3) The opening direction is the same, there is an angle between the fifth through hole (9-2) and the fourth through hole (9-1); the flame stabilizer (10) extends from the second cylinder into the rear casing (4), And connected with the second cylinder.