Method of providing stable vibration combustion in intermittent combustion chambers

Abstract

FIELD: furnaces and stoves.SUBSTANCE: method for providing stable vibration combustion in intermittent combustion chambers, consisting in air supply through a valve, its subsequent mixing with fuel and ignition, blowing is performed on suction cycle through inlet valve – aerodynamic or mechanical, with subsequent arrangement of intensive mixing in combustion chamber by combustion zone jet blowing with formation of annular vortices, differing from known processes in that combustion products are bled from resonant tube to blow them into intermittent combustion zone via inlet valve and to feed combustion products by excess pressure in resonant tube via main line and check valve.EFFECT: reliability of the pulsating combustion chamber is increased by bypassing and recirculating part of the exhaust gases from the resonance tube into the pulsating combustion zone through an air valve and creating favourable conditions for maintaining pulsating combustion.1 cl, 1 dwg

Description

[0001] The invention relates to pulsating combustion chambers and can be used as a propulsion device for small unmanned aerial vehicles - unmanned reconnaissance aircraft, flying targets, etc., as well as heating or thermal elements in aerosol generators of "hot" fog, air or gas heaters, water heaters, thermal boilers, etc.

[0002] A method is known for operating a supersonic ramjet engine with a pulsating combustion mode, which consists in that the fuel for starting the engine is supplied to the first belt of a section of a constant cross-section of the combustion chamber and a pulsating combustion mode is initiated with the periodic formation of a wave structure of the pseudo-shock type from heat and gas dynamic impulses, for example, a plasma, a shock wave, a gas jet of an inert or reactive medium that promotes combustion intensification, implementing a change in the combustion mode in the section of the constant cross-section of the combustion chamber from diffusion to pseudo-shock and back when the head of the pseudo-shock approaches the fuel supply point, or a mixed periodic diffusion-pseudo-shock, or a quasi-stationary pseudo-shock when the frequency of heat and gas dynamic impulses changes, while further operation of the engine is ensured by supplying fuel to the subsequent belts of sections of the variable cross-section of the combustion chamber (RU No. 2446305,2012).,

[0003] A method for boosting a dual-circuit ejector pulse jet engine is known, which includes purging the chamber with a fuel-air mixture of combustion from mixers and air from an aerodynamic valve of the second circuit, forming an air jet blowing of the combustion zone, subsequent ignition and explosion with the ejection of combustion products through a resonator tube, mixers and an aerodynamic valve, the supply of fuel during engine operation is carried out simultaneously in two engine circuits with the subsequent organization of intensive mixing in the combustion chamber by jet blowing of the fuel-air mixture of the combustion zone with the formation of ring vortices (RU No. 2608427, 2017).

[0004] The closest solution in technical essence is a method of two-circuit purging of a pulse jet engine, which consists of supplying air through a valve, followed by mixing it with fuel and ignition, characterized in that purging in the suction cycle is carried out simultaneously through two circuits of different types of intake valves - aerodynamic and mechanical, with the subsequent organization of intensive mixing in the combustion chamber by jet blowing of the combustion zone with the formation of ring vortices, additionally, blowing is carried out towards the main flow of a gas stream from an ejector pre-chamber located on the end wall of the combustion chamber (RU No. 2608427, 2017).

[0005] The main disadvantage is that when working stationary, on the ground, a sudden shutdown occurs, the vibration combustion stops, due to the flame failure in the pulsating combustion chamber with various types of valves.

[0006] The technical task is to increase the reliability of the pulsating combustion chamber by bypassing and recirculating part of the exhaust gases from the resonance tube into the pulsating combustion zone through an air valve and creating favorable conditions for maintaining pulsating combustion.

[0007] The technical result is to increase the efficiency of the pulsating combustion chamber by maintaining the vibrational combustion of the flame in the pulsating combustion chamber with various types of valves, including without movement of the pulsating combustion chamber on the ground.

[0008] The essence of the method for ensuring stable vibration combustion in pulsating combustion chambers, which consists of supplying air through a valve, subsequently mixing it with fuel and ignition, purging is carried out in the suction cycle through an inlet valve - aerodynamic or mechanical, with the subsequent organization of intensive mixing in the combustion chamber by jet blowing of the combustion zone with the formation of ring vortices, combustion products are taken from a resonance tube, combustion products are blown into the pulsating combustion zone through the inlet valve, and combustion products are supplied due to excess pressure in the resonance tube through a line and a check valve.

[0009] The novelty lies in the fact that combustion products are taken from the resonance tube, the combustion products are blown into the pulsating combustion zone through the inlet valve, and the combustion products are supplied due to excess pressure in the resonance tube through the main line and the check valve.

[0010] Analysis of known technical solutions (analogues) in the field under study and related fields allows us to conclude that they do not contain features similar to the essential distinctive features in the claimed device.

[0011] The proposed technical solution is industrially applicable, since it can be manufactured industrially, is operational, feasible and reproducible, and therefore meets the patentability requirement of "industrial applicability".

[0012] The figure shows the general appearance of the device.

[0013] The method for ensuring stable vibration combustion in pulsating combustion chambers is implemented in an installation that contains a combustion chamber 1 with an installed spark plug 2, a resonance tube 3, a confuser 4, an air mechanical valve 5, in which a fuel injector 6 is installed.

[0014] Additionally, a gas sampling nipple 7 is installed from the resonance tube at a distance of λ / 4, where λ is the pressure wavelength, from the beginning of the combustion chamber 1. The nipple 7 is connected to the exhaust gas line 8, with the gas inlet nipple 9 into the mechanical air valve 5 through the recirculated gas check valve 10.

[0015] The device operates as follows.

[0016] Air is supplied through mechanical air valve 5, mixed with fuel through fuel injector 6, and ignited by spark plug 2. The mixture, burning at constant volume, forms a gas with a core temperature of approximately 1200° K and elevated pressure. Hot gas under excess pressure flows through resonance tube 3, and the combustion cycle ceases. In this case, the hot gas, passing through resonance tube 3, by inertia entrains gas masses from pulsating combustion chamber 1 and creates a pressure differential between the interior of pulsating combustion chamber 1 and the external environment. Purging is carried out during the suction cycle through inlet valve 5—aerodynamic or mechanical—followed by intensive mixing in combustion chamber 1 by jet blowing across the combustion zone, forming annular vortices.Combustion products are taken from resonance tube 3, blown into the pulsating combustion zone through inlet valve 5, and the combustion products are supplied due to excess pressure in resonance tube 3 through exhaust gas line 8 and check valve 10, through gas inlet fitting 9 into mechanical air valve 5.

[0017] The proposed method for ensuring stable vibration combustion in pulsating combustion chambers significantly increases the reliability of the pulsating combustion chamber by bypassing and recirculating part of the exhaust gases from the resonance tube into the pulsating combustion zone through an air valve and creating favorable conditions for maintaining pulsating combustion with various types of valves, including without movement of the pulsating combustion chamber on the ground.

Claims

A method for ensuring stable vibration combustion in pulsating combustion chambers, which consists of supplying air through a valve, subsequently mixing it with fuel and ignition, purging is carried out in the suction cycle through an inlet valve - aerodynamic or mechanical, with subsequent organization of intensive mixing in the combustion chamber by jet blowing of the combustion zone with the formation of ring vortices, characterized in that combustion products are selected from a resonance tube, combustion products are blown into the pulsating combustion zone through the inlet valve, and combustion products are supplied due to excess pressure in the resonance tube through a line and a check valve.

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