SU1716253A1 - Fuel mixture pulse combustion device - Google Patents

Abstract

The invention relates to the field of energy, in particular to the combustion of gas and gas-dispersed systems, mainly to the generators of high-temperature and high-speed flows of combustion products and can be used for processing materials and coating. The purpose of the invention is to increase operational reliability. A device for pulsed combustion of a combustible mixture contains a chamber in the form of a barrel, a gas supply system, an annular ignition chamber with an igniter of the combustible mixture located around the barrel and connected to its working cavity by holes, the igniter and the holes connecting the ignition chamber to the working cavity, are spaced from each other at a distance of 3 'I 80 b along the axis passing through the centers of the cross sections of the ignition chamber, where b is the minimum cross section of the ignition chamber, and in this chamber A transverse partition is installed, near which there is an igniter on one side and openings on the other side connecting the ignition chamber with the working cavity of the barrel. 1 hp f-ly, 4 ill.

Description

The invention relates to the field of energy, namely to the technique of burning gas and gas-dispersed systems, mainly to generators of high-temperature and high-speed jets of combustion products, can be used for processing materials and coating.

Apparatus for pulsed combustion of a combustible mixture, having a cylindrical shape, closed and open ends, openings for connection to a gas supply system and an igniter of a combustible mixture, are known. These chambers usually operate in the detonation mode of combustion and allow to generate high-speed and temperature gas flows. The disadvantage of these chambers is the considerable length of the pre-detonation site, since the ignition of the combustible mixture in the barrel occurs from a point source. This makes it difficult, and in some cases makes it impossible to use acetylene as a substitute gas for combustible gases.

A combustion chamber, adopted as the prototype of the present invention, is also known. It contains a barrel with an open output end, a gas supply system, an ignition chamber, covering the barrel and connected to its working cavity by openings, a combustible mixture igniter and a control unit. In this pulsed combustion chamber, the acceleration of the transition of the detonation is accomplished by realizing the ignition of the combustible mixture in the barrel from several torches, pulling out

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Calibration holes connecting the ignition chamber with the working cavity of the barrel.

The disadvantage of this impulse combustion chamber is the impossibility of the formation of flares from all openings simultaneously, since they are at different distances from the igniter of the combustible mixture. Ignition of the combustible mixture in the barrel in this case is carried out by two streams of flame propagating through the annular cavity of the chamber from the igniter of the combustible mixture sequentially starting from the holes located closer to the igniter of the combustible mixture. And by the time when these two streams of flame collide and form a zone with enhanced energy characteristics, in the part of the barrel adjacent to the ignition chamber, there will already be combustion products of part of the combustible mixture. This reduces the reliability of ignition of the combustible mixture in the trunk. - detonation distance.

The aim of the invention is to improve the operational reliability of the device for pulsed combustion of the combustible mixture due to the intensification of the process of initiating detonation in the barrel.

To achieve this goal, in a device containing a working chamber in the form of a barrel with an open output end, a gas supply system, an annular ignition chamber with an igniter of a combustible mixture located around the barrel and connected to its working cavity by the holes and the control unit, the igniter and holes, connecting the ignition chamber with the working cavity of the barrel are spaced from each other at a distance I along the axis passing through the center of the cross sections of the ignition chamber:

3b l 80b,

where b is the minimum cross-sectional size of the ignition chamber.

The choice of this ratio of sizes is determined by the conditions for the occurrence of detonation during burning acceleration in pipes and the characteristic values of the detonation distance (from the ignition point to the place of the detonation origin). The magnitude of the pre-detonation distance depends on the composition, temperature, pressure of the combustible gas mixture, diameter or other characteristic size of the channel cross-section, and other conditions.

According to physical studies, the pre-detonation distance is usually in the range of 2-4 diameters to 80 pipe diameters. Characteristic

the values determine the ratio of the dimensions of the ignition chamber in the proposed device.

With this design

In the ignition chamber, two streams of accelerating flame are formed, passing into detonation. Detonation waves that form in the ignition chamber excite detonation in the working cavity of the barrel in a shorter part of the barrel than during flare ignition.

In the annular ignition chamber, a transverse partition can be installed, near which there is an igniter on one side, and another aperture connecting the ignition chamber with the working cavity of the barrel.

In this embodiment, the minimum diameter of the annular ignition gauge is achieved, thereby minimizing the overall dimensions of the device.

Fig. 1 shows a device for pulsed combustion of a combustible mixture; figure 2 - section aa in figure 1; on fig.Z. 5 a device with an ignition chamber with a transverse partition; figure 4 - section bb in fig.Z.

The device for pulsed combustion of the combustible mixture shown in Fig. 1 contains the barrel 1 with an open-end, a gas supply system 2, an annular ignition chamber 3 located around the barrel 1 near its closed end and connected to the working cavity of the barrel 1 with holes four,

5 igniter 5 combustible mixture, mounted in the ignition chamber 3, and block 6. management The igniter 5 and the aperture 4 are spaced from each other at a distance of I I 80 b along the axis passing

0 through the centers of the cross sections of the ignition chamber 3, where b is the minimum cross section of the chamber 3, the control block B is connected to the gas supply system 2 and the igniter 5, and the feed system 2

5 gases with chamber 3 ignition.

A device for pulsed combustion of a combustible mixture works as follows.

The gas supply system 2 at the command of the control unit 6 fills the ignition chamber 3 and the barrel 1 with a combustible gas mixture. At the command of the control unit 6, the igniter 5 initiates the burning of the combustible mixture in the ignition chamber 3. Combustion propagates through the annular ignition chamber 3 in two directions from the igniter 5 of the combustible mixture, and two detonation waves are formed in it, which then collide at the openings 4 connecting the ignition chamber 3 with the working cavity of the barrel.

In the place of the collision of these waves, a zone with enhanced energy characteristics is formed, from which detonation is excited in the working cavity of the trunk.

The device for pulsed combustion of the combustible mixture, shown in Fig. 2, comprises a barrel 1 with an open output end, a gas supply system 2, an annular ignition chamber 3 connected to the working cavity of the barrel 1 and an aperture 4, a combustible igniter 5 mounted into ignition chamber 3, and control unit 6. In the ignition chamber 3, a transverse partition 7 is installed. On one side of the partition 7 there is an igniter 5, on the other side an opening 4 connecting the ignition chamber 3 with the working cavity of the barrel 1.,.

The igniter 5 and the orifice 4 are spaced from each other at a distance of 3 b I 80 b along the axis passing through the centers of the cross sections of the ignition chamber 3, where b is the minimum cross section of the chamber. The control unit 6 is connected with the igniter 5 and the gas supply system 2, and the latter with the ignition chamber 3.

A device for burning a combustible mixture works as follows.

The gas supply system 2, at the command of the control block b, fills the ignition chamber 3 and the barrel 1. With a j-gas mixture, ho The command of the control block J6 igniter 5 initiates the combustion of the combustible mixture in the ignition chamber 3. Combustion propagates through the annular ignition chamber 3, a detonation wave is formed, which then, through the openings 4, initiates detonation in the working cavity of the barrel.

The proposed solution in comparison with the prototype has the following advantages.

The initiation of detonation in the working cavity of the barrel from detonation waves, which are preliminarily formed in the ignition chamber, makes it possible to reduce the length of the pre-detonation section of the barrel. This makes it possible to increase the stability of the transition to detonation, to use trunks of shorter length and then volume (saving the combustible mixture in this case is 5 ... 10%). In addition, it is possible to use combustible gases less prone to detonation than acetylene, which at the same time are cheaper and less scarce; With detonation gas spraying, the cost of coatings in this case will be significantly reduced.

Claims (2)

Claim 1. A device for pulsed combustion of a combustible mixture comprising a working chamber in the form of a barrel with an open end face, a gas supply system, an annular ignition chamber with an igniter of the combustible mixture located around the barrel and connected to its working cavity, and a control unit, from l and ya e so that, in order to increase operational reliability, the igniter and the holes connecting the ignition chamber with the working cavity of the barrel, are located from each other at an axis distance of 80 od through the center of the cross sections of the ignition chamber where b - the minimal dimension of the cross section of the ignition chamber. 2. The device according to claim 1, in which there is a transverse partition in the annular ignition chamber, near which there is an igniter on one side and an opening on the other side connecting the ignition chamber with the working trunk cavity.