RU2352864C1 - Method and device for burning fuel - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: present invention relates to fuel combustion and can be used in gas-turbine engines and power installations, in installations for reprocessing and recycling domestic and industrial wastes. The method of burning fuel involves feeding fuel and air into a combustion liner of a combustion chamber and burning the fuel-air mixture. After that, the combustion products are removed from the combustion chamber through an outlet channel. Part of the air gets into the combustion chamber from the outlet channel of combustion products towards the axial direction of the burnt fuel, coming into the combustion chamber through a central opening of a central nozzle passage. The incoming air is swirled, forming a peripheral spiral vortex inside the combustion liner. The other part of the air is fed through a circular nozzle passage around the central nozzle passage towards the axial movement of the peripheral spiral vortex, swirling air in the direction coinciding with the direction of rotation of the peripheral spiral vortex, with formation of a paraxial vortex. Conditions are thus created, for injecting (sucking in) fuel into the combustion liner through the central opening of the central nozzle passage. That way the fuel-air mixture is prepared and ignited with a jet fire, coming from the burning device at a tangent to the peripheral spiral vortex in the direction of its rotation. In the region of the central opening of the central nozzle passage, a toroidal vortex is created, due to rotation of the peripheral vortex in the axial direction in the opposite side. The burning device is placed in the region of the outlet channel of combustion products. More working fuel is fed into the peripheral vortex.

EFFECT: provision for a working process of burning fuel with pressure of fuel at the outlet of the device below the pressure of incoming air.

18 cl, 4 dwg

Description

The present invention relates to the field of fuel combustion and may find application in gas turbine engines and power plants, in plants for the processing and disposal of domestic and industrial waste.

A known method and device for burning fuel, containing a main combustion chamber and a primary combustion chamber located in a section perpendicular to the central axis of the flame tube of the main combustion chamber. The main combustion chamber contains a flame tube, a swirl and a channel for the exit of combustion products located in one section perpendicular to the central axis of the chamber, fuel nozzles. The primary combustion chamber contains a flame tube, a swirl ring, fuel nozzles, a burner device and a combustion products outlet channel directed tangentially to the side surface of the flame tube of the main combustion chamber in the direction of flow rotation. The primary combustion chamber is located behind the swirl or in one section with the swirl of the main combustion chamber (see patent RU 2196940 C1, 01/20/2003).

The known technical solution does not provide stable operation and completeness of combustion at a low positive pressure difference between the supplied air and fuel and cannot realize the combustion process at a fuel pressure at the inlet equal to or less than the pressure of the supplied air. This significantly narrows the scope of its application.

Closest to the claimed method of burning fuel is the method of burning fuel described in patent RU 2212003 C1, 09/10/2003, which consists in the fact that the combusted fuel and air are supplied to the combustion tube of the combustion chamber, the air-fuel mixture is burned, after which the combustion products are removed from the chamber combustion through the outlet channel of combustion products.

Closest to the claimed device for burning fuel is a device also described in patent RU 2212003 C1, 09/10/2003, including a burner device, a main combustion chamber containing a flame tube, a rear swirl with a device for supplying air and an exit channel for combustion products, as well as a primary a combustion chamber mounted in front of the main combustion chamber along its axis and containing located on the front end of the device for supplying combustible fuel, air and a front swirler, made in the form of a twisting about the nozzle apparatus.

The disadvantage of these methods and devices for burning fuel is that they do not provide a combustion process when the fuel pressure at the inlet of the device is lower than the pressure of the supplied air, due to the inability to provide a high average axial gradient of static pressure and directing it towards the air supply device in the mode combustion and, as a consequence, a decrease in the process of fuel ejection from an external source, including the emission of combustion products from the axial vortex in the direction of the external and source.

The technical result of the claimed group of inventions is to provide a working process of burning fuel at a fuel pressure at the inlet of the device below the pressure of the supplied air.

The specified technical result is achieved by a method of burning fuel, which consists in the fact that the combusted fuel and air are fed into the combustion tube of the combustion chamber, the air-fuel mixture is burned, after which the combustion products are removed from the combustion chamber through the exit channel of the combustion products. According to the invention, part of the air is fed into the combustion chamber from the side of the exhaust gas outlet channel towards the axially directed combustible fuel, which enters the combustion chamber through the central hole of the central nozzle channel, the supplied air is twisted, forming a peripheral spiral vortex inside the flame tube, another part of the air is fed through the annular nozzle channel around the central nozzle channel towards the axial movement of the peripheral spiral vortex, swirling air in the direction coinciding with the direction of rotation of the peripheral spiral vortex, with the formation of an axial vortex and creating conditions for ejection (suction) into the flame tube through the central hole of the central nozzle channel of the combusted fuel, thus ensure the preparation of the air-fuel mixture and ignite it with a burning torch coming from the burner device tangentially into a peripheral spiral vortex along its rotation. A toroidal vortex is created in the region of the central opening of the central nozzle channel due to the rotation of the peripheral vortex in the axial direction in the opposite direction. The burner device is located in the area of the outlet channel of the combustion products. The peripheral vortex is additionally supplied with working fuel.

The indicated technical result is also achieved by means of a fuel combustion device including a main combustion chamber containing a burner, a heat pipe, a rear swirler with an air supply device and an exit channel of combustion products, as well as a primary combustion chamber installed in front of the main combustion chamber along its axis and containing located on the front end of the device for supplying combustible fuel, air and a front swirler, made in the form of a swirling nozzle apparatus. According to the invention, the burner device is located in the main combustion chamber, and the primary combustion chamber is formed by the outer and inner shells forming an annular nozzle channel connected on one side to the front swirl and, on the other hand, to the flame tube of the main combustion chamber, while the inner shell forms a central nozzle channel connected to the device for supplying combustible fuel to the primary combustion chamber, and the edge of the inner shell forming the central opening of the inlet of the central the nozzle channel into the flame tube, is located from the rear swirler not further than the edge of the outer shell facing the flame tube. The main combustion chamber is equipped with a device for supplying additional working fuel, made in the form of at least two jet nozzles located uniformly around the circumference of the flame tube in the region of the rear swirler. The burner is located in the area of the rear swirl. The length of the flame tube from the cross section of the rear swirl of the main combustion chamber to the edge of the inner shell forming the central hole is 1.5-2.5 times the diameter of the flame tube in the region of the rear swirl. The diameter of the Central hole of the inner shell of the primary combustion chamber is 0.4-0.8 of the diameter of the inlet of the channel of the exit of the combustion products of the main combustion chamber. The diameter of the inlet of the channel of the exit of combustion products of the main combustion chamber is 0.6-0.8 of the diameter of the flame tube in the region of the rear swirler. The outer and inner shells are made in the form of sections tapering towards the flame tube and mating with them in minimal sections of cylindrical sections made in the form of shells. The length of the cylindrical shell mating with the tapering section of the outer shell is no more than 2 radial widths of the annular nozzle channel in its minimum section, and the mating with the tapering section of the inner shell is not more than 4. The narrowing angle of the outer shell of the primary combustion chamber in the direction of the flame tube is no more than 16 °. The narrowing angle of the inner shell of the primary combustion chamber in the direction of the flame tube is not more than 12 °. The end surface of the flame tube in the region of the central hole is made torus, paired with a cylindrical or conical surface of the flame tube. The edges of the outer and inner shells of the primary combustion chamber are displaced into the flame tube to a distance of up to 0.5 times the diameter of the minimum circumference of the end torus surface of the flame tube. The edge of the inner shell of the primary combustion chamber is displaced into the flame tube relative to the edge of the outer shell by a distance of not more than 4 radial widths of the annular nozzle channel of the primary combustion chamber in its minimum section.

Thus, the new distinctive features introduced into the device for burning fuel in combination with the known features allow us to solve the problem.

Figure 1 shows a longitudinal section of a device for burning fuel;

figure 2 is a section along aa in figure 1;

figure 3 is a section along BB in figure 1, rotated 180 °;

figure 4 is a section along BB in figure 1.

A device that implements the claimed method of burning fuel (see figure 1) contains a main combustion chamber 1 and a primary combustion chamber 2 mounted in front of the main combustion chamber 1 along its axis. The main combustion chamber 1 contains a flame tube 3, an air supply device 4, a rear swirler 5 and a combustion products outlet channel 6 with an inlet 7 (see FIG. 2) located in one section perpendicular to the central axis of the main combustion chamber 1, and a burner device 8 (see Fig. 3) located in the region of the rear swirl 5. The burner device 8 comprises a channel 9 for the exit of combustion products tangentially directed to the side surface of the flame tube 3 in the direction of rotation of the stream exiting the back swirl 5. The surface of the flame tube 3, made cylindrical or conical with an increase in diameter in the direction of the primary combustion chamber 2, passes into the end torus surface 10. The primary combustion chamber 2 contains (see Fig. 4) a device 11 for supplying combustible fuel located on the front end , the device 12 of the air supply and the front swirl 13, made in the form of a swirling nozzle apparatus. The primary combustion chamber 2 is formed by the outer and inner coaxial shells, 14 and 15, respectively, forming an annular nozzle channel 16, connected on one side to the front swirl 13, and on the other hand to the flame tube 3 of the main combustion chamber 1. The inner shell 15 forms a central a nozzle channel 17 with a central hole 18 in the exit section of the channel 17 into the flame tube 3 of the main combustion chamber 1. The central nozzle channel 17 is connected to the device 11 for supplying combustible fuel to the primary combustion chamber 2. Price diameter the swirl hole 18 of the inner shell 15 of the primary combustion chamber 2 may be equal to 0.4-0.8 the diameter of the inlet 7 of the channel 6 of the output of the combustion products of the main combustion chamber 1. The diameter of the inlet 7 of the channel 6 of the output of the combustion products of the main combustion chamber 1 may be equal 0.6-0.8 diameter of the flame tube 3 in the region of the rear swirler 5. The length of the flame tube 3 from the cross section of the rear swirler 5 of the main combustion chamber 1 to the edge of the inner shell 15, forming the Central hole 18, may be 1.5-2, 5 diameters the flame tube 3 in the region of the rear swirler 5. The specified edge of the inner shell 15 is located from the rear swirl 5 not further than the edge of the outer shell 14 facing the flame tube 3. The outer and inner shells, respectively 14 and 15, of the primary combustion chamber 2 can be made 3 sections tapering towards the flame tube with narrowing angles of not more than 16 ° for the shell 14 and not more than 12 ° for the shell 15. The narrowing sections of the outer and inner shells 14 and 15 in minimal sections are mated with cylindrical stakes made in the form of shells 19 and 20, respectively. The length of the cylindrical shell 19 mating with the tapering section of the outer shell 14 is not more than 2 radial widths of the annular channel 16 in its minimum section, and the length of the shell 20 mating with the tapering section of the inner shell 15 is not more than 4. The edges of the outer and inner the shells 14 and 15 of the primary combustion chamber 2 can be displaced into the flame tube 3 to a distance of up to 0.5 times the diameter of the minimum circumference of the end torus surface 10 of the flame tube 3. The end torus surface 10 can be located in the central region 18. The edge of the inner shell 15 of the primary combustion chamber 2 can be displaced into the flame tube 3 with respect to the edge of the outer shell 14 by a distance of not more than 4 radial widths of the annular channel 16 of the primary combustion chamber 2 in its minimum section. The main combustion chamber 1 can also be equipped with a device for supplying additional working fuel, made, for example, in the form of jet nozzles 21 located uniformly around the circumference of the flame tube 3 in the region of the rear swirler 5.

The method of burning fuel is implemented as follows. Air from an external source is supplied to the air supply devices 4 and 12 of the main combustion chamber 1 and the primary combustion chamber 2, respectively. From device 4, air enters the rear swirl 5 of the main combustion chamber 1, forming a strongly swirling flow at the entrance to the flame tube 3, forming a peripheral vortex in the flame tube 3, which moves in the direction of the primary combustion chamber 2. The peripheral vortex excites a strongly swirling flow in the axial zone of the flame tube 3 — the axial vortex, which is in countercurrent to the peripheral vortex, while the rotation of the peripheral and axial vortices coincides. At the vortex separation boundary, the flow is highly turbulent with the formation of anisotropic turbulence, which prevails in the radial direction. As a result of this, in the near-axis zone of the flame tube 3, in the area of mixing air and fuel flows from the primary combustion chamber 2, and the rotation of the peripheral vortex into the near-axis zone of the flame pipe 3, an air-fuel mixture begins to form, which excites a toroidal vortex of the air-fuel mixture in the peripheral region. As a result of the supply of air and fuel to the burner device 8, an air-fuel mixture is formed in it, which is ignited by the spark plug. This ensures at the outlet of the burner device 8 the formation of a high-temperature torch of combustion products, which enters tangentially into the peripheral vortex of the flame tube 3, igniting the prepared air-fuel mixture. The air supplied to the air supply device 12 of the primary combustion chamber 2 enters the front swirl 13, where it accelerates with increasing peripheral speed, forming in the annular channel 16 a highly swirling high-speed air flow with a high radial gradient of static pressure. In the zone of fuel exit from the central hole 18 to the flame tube 3, the total radial gradient of the static pressure increases, since the directions of the peripheral velocities of the air flows leaving the rear swirl 5 of the main combustion chamber 1 and the front swirl 13 of the primary combustion chamber 2 coincide in direction. In the axial vortex of the flame tube 3, the radial static pressure gradient forms a high axial static pressure gradient directed towards the fuel supply device 11. This leads to the process of ejection of the burned fuel from an external source through the fuel supply device 11 and the central hole 18 of the inner shell 15 into the axial vortex main combustion chamber 1.

When burning low-potential or irrigated fuel or fuel with a variable calorific value, to obtain the specified parameters of the combustion products at the outlet of the combustion chamber and to stabilize the working process, high-potential liquid fuel is supplied to the peripheral vortex through the nozzles 21, which has a constant heat of combustion and which together with the air of the peripheral vortex forms air-fuel mixture. Regulation of fuel consumption through the nozzles allows you to get the desired temperature in the combustion zone and, accordingly, the combustion temperature at the outlet of the combustion chamber. So, for example, when burning pyrolysis gas obtained by thermal processing of medical or biohazardous waste, it is necessary to ensure that the temperature in the combustion zone of the main combustion chamber is not lower than 1300 ° С. When burning pyrolysis gas obtained in a thermochemical reactor of a domestic and industrial waste processing plant, in order to break up all hydrocarbon components and eliminate their subsequent synthesis, it is necessary to ensure that the temperature in the combustion chamber combustion zone is not lower than 1600 ° C with subsequent “freezing” of chemical reactions to exit from the combustion chamber.

The placement of the fuel nozzles 21 uniformly around the circumference in the plane of the rear swirl 5 or between the swirl 5 and the plane of the burner 8 leads to an increase in the quality of the air-fuel mixture, the preparation of which is carried out in a peripheral vortex at the beginning of its formation.

The use of jet fuel injectors 21 ensures the completion of the formation of the air-fuel mixture in the zones of the end torus surface 10 and the central hole 18 of the primary chamber 2, which eliminates the possibility of premature ignition of the air-fuel mixture in the peripheral vortex and, thereby, overheating of the walls of the flame tube 3. Fire lane of a high-temperature torch of combustion products coming tangentially from the burner 8 into the peripheral vortex, ignites the prepared fuel-air cm Camping.

The use of fuel supply from the output channel of the nozzles 21 along the radius of the flame tube 3 contributes to the creation of a uniform film of fuel on the inner surface of the flame tube 3, providing additional cooling of the flame tube due to the evaporation of fuel.

To ensure the required average value and direction of the axial gradient of static pressure in the plane of the central hole 18, which provides fuel ejection from an external source into the fuel supply device 11 during its combustion in the axial vortex of the flame tube 3, it is necessary to ensure the direction of the axial gradient of static pressure in the plane of the inlet 7, similar to the direction of the gradient in the central hole 18. Due to the fact that in the combustion mode, the volumetric flow rate of combustion products increases due to To reduce their density with increasing temperature, it is necessary to make the diameter of the central hole 18 of the inner shell 15 of the primary combustion chamber 2 equal to 0.4-0.8 of the diameter of the inlet 7 of the channel 6 of the output of the combustion products of the main combustion chamber 1. A smaller diameter of the central hole 18 corresponds to the use the air supplied to the primary combustion chamber 2, equal to the pressure of the air supplied to the main combustion chamber 1. A larger diameter of the Central hole 18 corresponds to the use of air and supplied to the primary combustion chamber 2, pressure greater than the pressure of air supplied to the main combustion chamber 1.

To ensure equal direction of axial gradients of static pressure in the cross sections of the holes 18 and 7 in the combustion mode, it is necessary to perform the diameter of the inlet 7 of the channel 6 of the exit of combustion products equal to 0.6-0.8 diameter of the flame tube 3 in the region of the rear swirler 5. Increase the diameter of the inlet holes 7 helps to reduce the average pressure inside the flame tube 3, to increase the circumferential component of the air velocity at the outlet of the rear swirler 5, and thereby increase the radial and axial gradients of the static who pressure.

When the peripheral vortex moves from the back swirl 5 towards the primary combustion chamber 2, the peripheral velocity component in the flame tube 3 decreases, which leads to a decrease in the fraction introduced by the peripheral vortex into the total radial gradient of static pressure in the cross section of the central hole 18. Therefore, the length of the flame tube 3 from the cross section of the rear swirl 5 to the edge of the inner shell 15, forming the Central hole 18, is chosen equal to 1.5-2.5 diameter of the flame tube 3 in the region of the rear swirl 5. The lower boundary with sponds greater proportion contributed by peripheral swirl to the total radial static pressure gradient, the upper limit - lower lobe. However, a decrease in the length of the flame tube 3 below the lower limit leads to a decrease in the volume of the main combustion chamber, which degrades the characteristics of the main combustion chamber in terms of completeness of combustion and emissions of carbon monoxide, hydrocarbons and smoke.

The displacement of the edges of the outer and inner shells 14 and 15 of the primary combustion chamber 2 into the flame tube 3 to a distance of up to 0.5 times the diameter of the minimum circumference of the end torus surface 10 of the flame tube 3 leads to the formation of a peripheral vortex of a toroidal stabilizing vortex, which is located between the torus surface 10, of the inner the surface of the flame tube 3 and the shells 19 and 20 of the outer and inner shells 14 and 15. When the main combustion chamber 1 is ignited, the air-fuel mixture ignites, forming a toroidal vortex and forming the first initial combustion zone. In the operating mode of the main combustion chamber, the initial combustion zone serves as the source of the stabilizing flame for the main combustion zone located in the axial vortex directly behind the central hole 18 of the inner shell 15.

The offset of the edge of the inner shell 15 into the flame tube 3 of the main combustion chamber 1 with respect to the edge of the outer shell 14 by a distance of not more than 4 radial widths of the annular nozzle channel 16 in its minimum section increases the peripheral velocity of the peripheral and axial vortices in a section adjacent to the central hole 18. An increase in this velocity leads to an increase in the radial and axial gradients of the static pressure in the cross section of the central hole 18 and, as a result, to an increase in the ejection coefficient of primary combustion chamber 2 of combusted fuel. The lower limit of displacement of the edge of the inner shell 15 is used when performing the flame tube 3 of the minimum length, when the peripheral speed of the peripheral vortex in the cross section of the Central hole 18 is large enough. The upper limit is during the execution of the flame tube 3 of the maximum length, when the peripheral speed of the peripheral vortex in the cross section of the central hole 18 is much less than the peripheral speed of the air leaving the annular channel 16.

The narrowing angle of the outer shell 14 of not more than 16 ° helps to prevent stalling and provides low pressure loss in the annular channel 16. A decrease in this angle below the upper boundary is accepted when the peripheral component of the air velocity of the front swirler 13 increases. The upper boundary is selected if it is impossible to provide enough high peripheral air velocity at the outlet of the front swirl 13 with the existing air differential. In this case, following the law of conservation of angular momentum, it is possible to increase the peripheral velocity component at the exit of the annular channel 16 with a slight increase in pressure loss.

The narrowing angle of the inner shell 15 of not more than 12 ° helps to prevent stalling and provides low pressure loss in the Central nozzle channel 17. The reduction of the narrowing of this angle below the upper boundary is accepted at high axial speed at the inlet to the fuel supply device 11. The upper boundary is taken at a low axial velocity at the entrance to the fuel supply device 11. In this case, following the continuity equation and increasing the average static pressure difference between the fuel injection zone into the device 11 and paraxial second vortex adjacent to the central opening 18, it is possible to increase the axial component of the velocity at the exit of the central bore 18 with a small increase in pressure loss.

To convert the radial components of the velocities of the air and fuel flows, respectively, into the axial components, at the exit from the annular channel 16 and at the exit from the central hole 18, the outer and inner shells 14 and 15 are mated with cylindrical shells 19 and 20 in the cross section of minimum diameters. fuel allows you to increase the effective diameter of the air stream from the annular channel 16 and the fuel stream at the outlet of the Central hole 18, respectively, which will lead to an increase in the corresponding flow s.

To complete the conversion of the radial components of the air and fuel flow velocities, respectively, to the axial components at the outlet of the annular channel 16 and at the exit of the central hole 18, the length of the cylindrical shell 19 is no more than 2 radial widths of the annular channel 16 in its minimum section, and for the shell 20 - no more than four.

Thus, the use of the proposed device for burning fuel allows for a working process of burning at a fuel pressure at the inlet of the device below the pressure of the supplied air, as well as process stability, a high temperature in the combustion zone and predetermined parameters of the combustion products at the exit of the combustion chamber when burning low-potential and watered fuel and fuel with variable calorific value.

Claims (18)

1. The method of burning fuel, which consists in the fact that the burned tube of the combustion chamber is fed with combustible fuel and air, the air-fuel mixture is burned, after which the combustion products are removed from the combustion chamber through the exhaust gas outlet channel, characterized in that part of the air is supplied to the combustion chamber from the side of the outlet channel of the combustion products towards the axial direction of the combustible fuel entering the combustion chamber through the Central hole of the Central nozzle channel, the supply air is twisted, forming inside a peripheral spiral vortex, another part of the air is fed through the annular nozzle channel around the central nozzle channel towards the axial movement of the peripheral spiral vortex, swirling the air in the direction coinciding with the direction of rotation of the peripheral spiral vortex, with the formation of an axial vortex and creating conditions for ejection ( aspiration) into the flame tube through the central opening of the central nozzle channel of the combusted fuel, thus providing fuel preparation ozdushnoy mixture is ignited and its burning torch, supplied from the burner tangentially into the peripheral spiral vortex in the course of its rotation. 2. The method according to claim 1, characterized in that in the region of the Central hole of the Central nozzle channel create a toroidal vortex, by rotating the peripheral vortex in the axial direction in the opposite direction. 3. The method according to claim 1, characterized in that the burner device is located in the area of the outlet channel of the combustion products. 4. The method according to claim 1, characterized in that the working fuel is additionally supplied to the peripheral vortex. 5. A fuel combustion device comprising a main combustion chamber comprising a burner device, a flame tube, a rear swirler with an air supply device and an exit channel of combustion products, as well as a primary combustion chamber mounted in front of the main combustion chamber along its axis and containing located on the front end devices for supplying combustible fuel, air and a front swirl made in the form of a swirling nozzle apparatus, characterized in that the burner device is located in the main chambers combustion, and the primary combustion chamber is formed by the outer and inner shells forming an annular nozzle channel connected on one side to the front swirl and, on the other hand, to the flame tube of the main combustion chamber, while the inner shell forms a central nozzle channel connected to the supply device fuel burned into the primary combustion chamber, and the edge of the inner shell, which forms the central hole of the entrance of the Central nozzle channel into the flame tube, is located from the rear swirl e edge of the outer shell facing the flame tube. 6. The device according to claim 5, characterized in that the main combustion chamber is equipped with a device for supplying additional working fuel. 7. The device according to claim 6, characterized in that the device for supplying additional working fuel is made in the form of at least two jet nozzles located uniformly around the circumference of the flame tube in the region of the rear swirler. 8. The device according to claim 5, characterized in that the burner device is located in the region of the rear swirler. 9. The device according to claim 5, characterized in that the length of the flame tube from the cross section of the rear swirl of the main combustion chamber to the edge of the inner shell forming the central hole is 1.5-2.5 times the diameter of the flame tube in the region of the rear swirl. 10. The device according to claim 5, characterized in that the diameter of the Central hole of the inner shell of the primary combustion chamber is 0.4-0.8 of the diameter of the inlet of the outlet channel of the combustion products of the main combustion chamber. 11. The device according to claim 10, characterized in that the diameter of the inlet of the outlet channel of the combustion products of the main combustion chamber is 0.6-0.8 diameter of the flame tube in the region of the rear swirler. 12. The device according to claim 5, characterized in that the outer and inner shells are made in the form of sections tapering towards the flame tube and mating with them in minimal sections of cylindrical sections made in the form of shells. 13. The device according to p. 12, characterized in that the length of the cylindrical shell mating with the tapering section of the outer shell is not more than 2 radial widths of the annular nozzle channel in its minimum section, and mating with the tapering section of the inner shell is not more than 4 . 14. The device according to p. 12, characterized in that the narrowing angle of the outer shell of the primary combustion chamber in the direction of the flame tube is not more than 16 °. 15. The device according to p. 12, characterized in that the narrowing angle of the inner shell of the primary combustion chamber in the direction of the flame tube is not more than 12 °. 16. The device according to claim 5, characterized in that the end surface of the flame tube in the region of the central hole is made torus, paired with a cylindrical or conical surface of the flame tube. 17. The device according to claim 5, characterized in that the edges of the outer and inner shells of the primary combustion chamber are displaced into the flame tube by a distance of up to 0.5 times the diameter of the minimum circumference of the end torus surface of the flame tube. 18. The device according to 17, characterized in that the edge of the inner shell of the primary combustion chamber is displaced into the flame tube relative to the edge of the outer shell by a distance of not more than 4 radial widths of the annular nozzle channel of the primary combustion chamber in its minimum section.

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