JPH10288090A - Misfire preventing device, ram jet engine and flying vehicle using this misfire preventing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a misfire preventing mechanism so as to continue for a long time. SOLUTION: This device is formed of a heat insulating material 3 of fixed to an inner wall of a metal chamber 2 of a combustion chamber 1 provided in the inside of an engine to be gradually scraped by combustion gas to be thinned and a combustion catalyst 24a to 24d always partly exposed from the insulating material 3 to be buried by stages in the insulating material 3 so as to change this exposed part as viewed from an inner wall of the combustion chamber 1 to perform stable combustion by a part exposed in the combustion chamber 1 in accordance with scraping the insulating material 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ramjet engine applied to a supersonic projectile propulsion device.

[0002]

2. Description of the Related Art A ramjet engine is accelerated to a supersonic speed by a solid rocket booster or the like, takes in air naturally compressed by a ram effect caused by a flight speed, and reacts and burns in a combustion chamber with a fuel to produce a Mach 2-3 supersonic speed. It is an engine for a supersonic flying object that can obtain the propulsion power of In a ramjet engine, it is an important issue to stabilize the flame so as not to misfire in the combustion chamber.

FIG. 4 is a cross-sectional view of a ramjet combustion chamber provided with a conventional misfire prevention device. FIG. 4 (a) is a cross-sectional view of the combustion chamber at an early stage of combustion, and FIG. FIG.
FIG. 2A is a cross-sectional view of the combustion chamber viewed from the direction of arrow E.
In FIG. 4A, the combustion gas enters from the right side, and the flame is held at the front part of the combustion chamber on the left side. Then, in order to prevent a misfire, the combustion catalyst 4 was attached to the front part of the combustion chamber 1 in the heat insulating material 3 internally attached to the inner wall of the metal chamber 2 so as to be positioned perpendicular to the thickness direction.

[0004]

In the conventional method of mounting the combustion catalyst 4, the entire combustion catalyst 4 is exposed to hot combustion gas at a stretch. Combustion chamber 1 during combustion progress
FIGS. 4C and 4D show the inside. As the combustion progresses, the heat insulating material 3 is shaved, but the catalytic activity of the catalyst 4 is lost at a stroke as shown in FIG.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a misfire prevention device for maintaining a misfire prevention mechanism for a long time, a ramjet engine and a flying object using the same. It is in.

[0006]

A misfire prevention device according to the present invention is attached to an inner wall of a combustion chamber, and is gradually cut and thinned by combustion gas, and a part thereof is always exposed from the heat insulation material. And a combustion catalyst embedded in the heat insulating material such that the position of the exposed portion as viewed from the inner wall side of the combustion chamber changes, and the heat insulating material is shaved off in the combustion catalyst. According to the above, the portion exposed in the combustion chamber is stably burned.

In a first preferred embodiment of the apparatus for preventing misfire according to the present invention, a combustion catalyst is embedded in a heat insulating material in a stepwise manner. As a second desirable mode of the misfire prevention device of the present invention, a combustion catalyst is embedded obliquely in the thickness direction of the heat insulating material.

According to another aspect of the present invention, there is provided a ramjet engine, comprising: a combustion chamber provided with the misfire prevention device according to claim 1; and a fuel supply installed upstream of the combustion chamber for supplying fuel to the combustion chamber. A fuel nozzle for spraying the fuel delivered from the fuel supply unit into the combustion chamber, an ignition device for igniting the sprayed fuel and burning the fuel in the combustion chamber, and a downstream side of the combustion chamber. And an exhaust nozzle for discharging combustion gas.

A flying object according to the present invention is a ramjet engine according to claim 2, a fuel tank for storing fuel to be fed into the ramjet engine, and a combustion chamber installed upstream of the ramjet engine. And an air intake duct for taking in the air to be sent into the air intake duct.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a cross-sectional view of a flying object according to a first embodiment of the present invention as viewed from the side. The flying object according to the present embodiment is divided into two, each of which has a front opening 13.
a, 13b, and two fuel nozzles 19a, 19b for injecting liquid fuel into each air intake duct 12a, 12b. At the rear of the flying object body 11, a fuel tank 15 for storing liquid fuel is provided.

At the rear of the fuel tank 15, the fuel tank 1
Pump 16 connected to the fuel pump 5 and the fuel pump 16
A branch pipe 20 and fuel pipes 18a and 18b that branch in two directions and connect the fuel nozzles 19a and 19b are provided in the flying object body 11. Branch pipe 20 and fuel pipe 18
a and 18b, two fuel control devices 17a and 17b for controlling the fuel injection amount of each fuel nozzle 19a and 19b.
Is provided. Each fuel control device 17a, 17b
It is connected to a pitot tube, a total pressure tube, or a static pressure measuring hole (not shown) provided in the air intake duct 12, and calculates the inflow air flow rate of the air intake duct 12 based on the detected pressure value. Nozzles 19a, 1
9b is configured to adjust the fuel injection amount.

Each of the air intake ducts 12a and 12b is connected to the common combustion chamber 1, and an exhaust nozzle 14 is connected to the rear of the combustion chamber 1. Reference numeral 21 denotes an ignition device provided immediately before the combustion chamber 1.

FIG. 2 shows a detailed configuration of the combustion chamber 1 in FIG. 2A is a cross-sectional view of the inside of the combustion chamber 1 as viewed from the side, and FIG. 2B is a view of the exposed surface of the combustion catalyst 24a in the combustion chamber 1 shown in FIG. FIG. As shown in FIG. 2 (a), a combustion chamber 1 surrounded by a metal chamber 2 has a heat insulating material 3 adhered to an inner wall thereof. The heat insulating material 3 is gradually cut and thinned by the combustion gas in the combustion chamber 1.

At the front of the combustion chamber 1, combustion catalysts 24a to 24d are embedded in a heat insulating material 3 adhered inside. The combustion catalysts 24a to 24d are each formed by supporting a metal such as platinum and rhodium on a base material such as a porous SiC body. It is embedded so that it has a configuration.

That is, the combustion catalysts 24a to 24d are gradually exposed in the combustion chamber 1 from those embedded on the surface side as the heat insulating material 3 is cut. At the stage when the combustion starts, only the combustion catalyst 24a is exposed in the combustion chamber 1. Since the heat insulating material 3 is gradually cut in the thickness direction, the combustion catalyst becomes 24b,
24c and 24d are exposed in this order.

FIG. 2C shows the inside of the combustion chamber 1 during the progress of combustion, and FIG. 2D shows the combustion chamber 1 shown in FIG. It is sectional drawing. As can be seen from FIG. 2 (c), the heat insulating material 3 is shaved by the progress of combustion, and the exposed combustion catalyst is changed to 24c. The exposed area of the combustion catalyst 24c exposed in the combustion chamber 1 is not different from the exposed area in the initial stage of combustion, as can be seen by comparing FIGS. 2B and 2D, but the exposed portion is from the inner wall of the combustion chamber 1. It is embedded so that it changes when you look at it.

The operation of the flying object according to this embodiment will be described. The liquid fuel stored in the fuel tank 15 and sent out from the fuel pump 16 is branched in two directions by a branch pipe 20, and then the fuel control devices 17a and 17b and the fuel pipe 1 respectively.
It is sent to fuel nozzles 19a and 19b through 8a and 18b, and is injected into each air intake duct 12a and 12b. The combustion control devices 17a and 17b adjust the fuel injection amount of the combustion nozzles 19a and 19b according to the flow rate of the inflow air in each of the air intake ducts 12a and 12b.

The fuel injected into the air intake duct 12 and the air fed into the air intake duct 12 are ignited by the igniter 10 so as to react and burn in the combustion chamber 1. In the early stage of combustion,
As shown in FIG. 2A, the combustion catalyst 24a exposed in the combustion chamber 1 functions to prevent misfire. As the combustion proceeds, the combustion catalyst 24a is sintered by the high-temperature combustion gas, and the catalytic activity is lost. As the combustion proceeds, the heat insulating material 3 is also thinned by the combustion gas. Accordingly, since the catalyst 24b comes into the combustion chamber in place of the combustion catalyst 24a having lost the catalytic activity, flame holding stability can be obtained, and the misfire prevention function is maintained.

When the combustion proceeds further, the heat insulating material is cut to the extent shown in FIG. 2C, so that the catalyst 24c appears.
Also at this stage, as shown in FIG. 2D, the exposed area of the combustion catalyst 24c does not change from the exposed area at the beginning of combustion, as can be seen from comparison with FIG. Thus, a misfire prevention function is not reduced. In the present embodiment, the duration of the misfire prevention function, which was 10 to 30 seconds in the conventional misfire prevention device, is significantly improved to 100 to 300 seconds.

As described above, the exposed combustion catalyst loses its activity as the combustion proceeds, but the active combustion catalyst functions sequentially, and the misfire prevention action is maintained for a long time. Therefore, the flame holding stability and the combustion efficiency of the ramjet engine having the misfire prevention function are remarkably improved. Also, the flying object itself can maintain the required speed, and can fly to a distant destination.

In this embodiment, the combustion catalysts 24a to 24d have a four-stage structure from the surface of the heat insulating material 3 to the deep part.
Although the case where 24d is used is shown, the number of stages does not matter, and it goes without saying that the present invention is applicable to a combustion catalyst composed of a plurality of stages.

(Second Embodiment) FIG. 3 is a sectional view of a misfire prevention device according to a second embodiment of the present invention. Note that the ramjet engine and the flying object using the misfire prevention device according to the present embodiment have the same configuration as that of the first embodiment except for the combustion chamber 1, and a description thereof will be omitted.

FIG. 3A is a sectional view of the inside of the combustion chamber 1 as viewed from the side, and FIG. 3B is an arrow C showing an exposed surface of the combustion catalyst 34 in the combustion chamber 1 shown in FIG. It is sectional drawing seen from the direction. As shown in FIG. 3 (a), the combustion chamber 1 surrounded by the metal chamber 2 has a heat insulating material 3 adhered to the inner wall thereof. Further, in the front part of the combustion chamber 1, a combustion catalyst 34 is embedded in the heat insulating material 3 adhered so as to be inclined with respect to the thickness direction of the heat insulating material 3. The heat insulating material 3 and the combustion catalyst 34 in the present embodiment are made of the same materials as those in the first embodiment.

The operation of the misfire prevention device according to the above embodiment will be described. As shown in FIG. 3A, a misfire prevention function is activated by the combustion catalyst 34 exposed in the combustion chamber 1 at the beginning of combustion. As the combustion proceeds, the combustion catalyst 34 is sintered by the high-temperature combustion gas, and the catalytic activity is lost. FIG. 3C shows a sectional view of the combustion chamber 1 during the progress of combustion. As the combustion proceeds, the heat insulating material 3 is also thinned by the combustion gas. Therefore, an active catalyst appears in the combustion chamber 1 instead of the combustion catalyst having lost the catalytic activity. That is, even at this stage, as shown in FIG. 3D, the exposed area of the combustion catalyst 34 did not change from the exposed area at the beginning of combustion as shown in FIG. A catalyst area can be obtained, and flame holding stability can be obtained without lowering the misfire prevention function. Also in the present embodiment, the duration of the misfire prevention function, which was 10 to 30 seconds in the conventional misfire prevention device, is significantly improved to 100 to 300 seconds. Even if combustion proceeds in this manner, a catalyst surface area having a constant area of activity is always obtained, and a stable misfire prevention function is maintained for a long time.

[0025]

As described above, according to the apparatus for preventing misfire of the present invention, a heat insulating material which is attached to the inner wall of a combustion chamber and is gradually cut and thinned by combustion gas, and a part of the heat insulating material And a combustion catalyst embedded in the heat insulating material so that the position of the exposed portion as viewed from the inner wall side of the combustion chamber changes. As the combustion progresses, the part exposed in the combustion chamber burns more stably, so as the combustion progresses, even if the combustion catalyst that originally functioned loses its activity, the newly active combustion catalyst will be It is exposed to the combustion chamber and the misfire prevention function works. Accordingly, the duration of the misfire prevention function is significantly increased without the combustion catalyst losing its activity at once by the combustion gas.

According to the ramjet engine of the present invention, a combustion chamber provided with the above-described misfire prevention device, a fuel supply unit installed upstream of the combustion chamber and supplying fuel to be sent into the combustion chamber, Misfire caused by having a fuel nozzle that sprays fuel delivered from a fuel supply unit into a combustion chamber, an igniter that ignites the sprayed fuel to burn in the combustion chamber, and an exhaust nozzle that discharges combustion gas. Stable remjet combustion is obtained, and the combustion efficiency is also improved.

According to the flying object of the present invention, the ramjet engine described above, a fuel tank for storing fuel to be fed to the ramjet engine, and a fuel tank installed upstream of the ramjet engine and fed into the combustion chamber Since the air intake duct for taking in air is provided, it is possible to fly to a distant destination without misfiring, and the required speed is increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of a flying object according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the misfire prevention device according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a misfire prevention device according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional ramjet combustion chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion chamber 2 Metal chamber 3 Heat insulating material 4, 24, 34 Combustion catalyst 11 Flying body 12a, 12b Air intake duct 13a, 13b Opening 14 Exhaust nozzle 15 Fuel tank 16 Fuel pump 17a, 17b Fuel control device 18a, 18b Fuel pipe 19a, 19b Fuel nozzle 20 Branch pipe 21 Ignition device

Claims (3)

[Claims] 1. A heat insulating material which is attached to an inner wall of a combustion chamber and is gradually cut and thinned by a combustion gas, and a part of the heat insulating material is always exposed and exposed when viewed from the inner wall side of the combustion chamber. And a combustion catalyst embedded in the heat insulating material such that the position of the heat insulating material is changed, and the combustion catalyst causes stable combustion by the portion exposed in the combustion chamber as the heat insulating material is cut. A misfire prevention device, characterized in that: 2. A combustion chamber provided with the misfire prevention device according to claim 1, a fuel supply unit provided upstream of the combustion chamber and supplying fuel to be fed into the combustion chamber, and a fuel supply unit A fuel nozzle that sprays the fuel delivered from the combustion chamber into a combustion chamber, an ignition device that ignites the sprayed fuel and burns the fuel in the combustion chamber, and is installed downstream of the combustion chamber;
A ramjet engine comprising an exhaust nozzle for discharging combustion gas. 3. The ramjet engine according to claim 2, a fuel tank for storing fuel to be sent to the ramjet engine, and an air provided upstream of the ramjet engine and taken into a combustion chamber. A flying object comprising an air intake duct.