RU2574156C2 - Multitube valveless engine with pulse detonation - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: engine comprises several detonation tubes, each including independent discharge outlet, interconnected in the common air-fuel intake inlet. Air-fuel mix detonates in detonation tubes simultaneously while common air-fuel mix inlet minimises the back pressure caused by said detonation by sending several shock waves toward each other at application of back pressures as reactive fronts and reduction of the effects of shock waves propagating backward and upstream. Said detonation tubes can be curved.

EFFECT: uniform power feed to the turbine.

22 cl, 12 dwg

Description

This application claims priority to US Application 61 / 354,829, filed June 15, 2010 and incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the generation of energy during combustion, in particular to pulsed detonation combustion.

State of the art

Over the past few decades, there has been significant interest in pulsed detonation technology due to its potential for highly efficient energy generation. Significant research has been carried out on the technology, implementation and improvement of pulsed detonation devices. One of the main problems in the field of pulsed detonation devices is the control of pressure pulses arising in the process of detonation, and in isolation from the impact of the supply pipe. There are a number of patents for various inlet valves for pulsed detonation engines. A number of studies have been carried out to create passive aerodynamic elements that work like active valves. These elements in the combustion device during detonation reduce the back pressure on the supply pipe without using moving parts. Such combustion devices are called engines (combustion devices) with pulse detonation.

Disclosure of invention

A valveless multi-tube engine with pulse detonation is proposed, including several detonation tubes, each detonation tube having an independent discharge outlet. These several detonation tubes are connected to each other in a common inlet of the air-fuel mixture. In the proposed engine, the air-fuel mixture detonates simultaneously in the detonation tubes, and the common inlet of the air-fuel mixture minimizes the back pressure caused by the detonation of the air-fuel mixture by directing several backward shock waves at each other, effectively using backpressures as reactive fronts for friend and effectively reducing the impact of shock waves propagating backwards, in the upstream direction.

The valveless multi-tube pulse detonation engine mentioned above may further include turbulators located in the detonation tubes, the turbulators being configured to increase the speed of flame propagation. These turbulizers may include a cochlea along the length of the detonation chamber portion of each detonation tube.

The valveless multi-tube pulse detonation engine described above may further include geometric elements located in the inlet openings of the combustion chambers, these geometric elements selected from the group consisting of tapering nozzles, expanding nozzles, porous plates and hydraulic diodes. These geometric elements significantly limit the wave propagation backward, compared with the wave propagation forward.

A valveless multi-tube engine with pulse detonation according to claim 1, wherein the common air inlet opening further includes an air inlet valve.

The proposed valveless multi-tube engine with pulse detonation can be made so that the exhaust openings of all detonation pipes are connected to one exhaust outlet. This embodiment may include a combined tapering nozzle nozzle.

The proposed valveless multi-tube engine with pulse detonation in one embodiment is designed so that the detonation tube output is connected to a turbine, which, in turn, is configured to generate mechanical power as a result of the combustion process in the valveless multi-tube engine with pulse detonation. This turbine in one embodiment is a volumetric motion device. One embodiment of such a volumetric motion device is disclosed in US Pat. No. 5,755,196, incorporated herein by reference.

In one embodiment, the detonation tubes are not straightforward. The description shows one example of a non-linear configuration in which non-linear detonation tubes include an arc with an angle substantially equal to 180 °.

A valveless multi-tube engine with pulse detonation is proposed, including several detonation tubes, each detonation tube including an independent outlet. In one embodiment, several detonation pipes are connected to each other in a common air inlet opening, each detonation pipe further comprising at least one fuel injector hydraulically connected to the detonation pipe to supply fuel to it. This embodiment can be made so that the air-fuel mixture detonates in the detonation pipes at the same time, with the common air inlet opening being designed to minimize back pressure by directing back shock waves at each other, effectively using their shock pressures as reactive fronts for a friend and effectively reducing the impact of shock waves propagating backward in the upstream direction.

The valveless multi-tube pulse detonation engine mentioned above may further include turbulators located in the detonation tubes, the turbulators being made adjustable to increase the speed of flame propagation. These turbulizers may include a cochlea along the length of the detonation chamber portion of each detonation tube.

The valveless multi-tube pulse detonation engine mentioned above may further include geometric elements in the inlets of the combustion chambers, these geometric elements may be narrowing or expanding nozzles, porous plates or hydraulic diodes, which substantially limit the backward propagation of the wave in comparison with the propagation of the wave forward. The pulseless detonation valveless multi-tube engine mentioned above may include an air valve in a common air inlet.

The proposed valveless multi-tube engine with pulse detonation can be made so that the exhaust openings of all detonation pipes are connected to one exhaust outlet. In one embodiment, a combined tapering nozzle is used to convert the independent outlets into a single exhaust outlet. This exhaust port of detonation tubes can be connected to a turbine, that is, to a volumetric motion device, so as to generate mechanical power using combustion products.

A valveless multi-tube engine with pulse detonation can be designed so that the detonation tubes are not linear. Indirect detonation tubes may include an arc with an angle of up to 180 ° or more.

A brief description of the graphic materials

FIG. 1 shows a perspective view of a combustion device in one embodiment.

FIG. 2 shows a sectional view of a combustion device in one embodiment, a first stage of the detonation process, and a shock / flame propagation front in the combustion device.

FIG. 3 shows a section through a combustion device in one embodiment, a second stage of the detonation process, and a shock / flame propagation front in the combustion device.

FIG. 4 shows a section through a combustion device in one embodiment, a third stage of the detonation process, and a shock / flame propagation front in the combustion device and intake manifold.

FIG. 5 shows a section through a combustion device in one embodiment, a fourth stage of the detonation process and a shock / flame propagation front in the combustion device and intake manifold.

FIG. 6 shows a section through a combustion device in one embodiment, a fifth stage of the detonation process, and a shock / flame propagation front in the combustion device and the air inlet.

FIG. 7 shows a section through a combustion device in one embodiment, a sixth stage of a detonation process, and a shock / flame propagation front in a combustion device.

FIG. 8 shows an embodiment of a combustion device with a nozzle nozzle and one exhaust port.

FIG. 9 shows a perspective view of an embodiment with a non-linear pipe of a combustion device.

FIG. 10 shows a front or rear view of the embodiment depicted in FIG. 9.

FIG. 11 is a side view of the embodiment shown in FIG. 9.

FIG. 12 shows a side view in partial cross-section of a front view of the embodiment depicted in FIG. 9.

The implementation of the invention

The multi-tube valveless combustion device disclosed here in one embodiment includes an inlet, ignition chambers, detonation chambers and an exhaust nozzle (exhaust nozzles). The combustion device operates without moving parts (excluding the fuel injector), and no valves are used on the air path. The operation of the combustion device is controlled by an air damper, fuel injection and ignition system.

Combustion device design

As shown in FIG. 1, the combustion device 1 in one embodiment operates according to the principle of pulsed detonation, in which the fuel burns instantly (detonates) at a constant volume, forming high pressure and high temperature combustion products that exit through the outlet 2 of the combustion device .

As shown in a partial section of FIG. 2, air enters the combustion device through the air inlet 5. The incoming air can be preheated before entering the combustion device with exhaust or heat transferred through the walls of the combustion device. Fuel is injected into the air stream and mixed with air in the intake manifold 4. The intake manifold has one opening 5 for air inlet and several outlet openings 6 of the manifold. Each outlet of the collector is connected to one detonation pipe 7. Each detonation pipe 7 includes a combustion chamber 8 and a detonation chamber 9.

While the combustion device itself may be valveless, the intake air valve 32 may be used outside the combustion device itself.

To improve the mixing of air and fuel in the intake manifold, turbulators 13, for example, Shchepkin spirals, can be used. The combustion chamber and the intake manifold can be equipped with scattering elements that evenly distribute air / fuel between detonation tubes 7, while minimizing the reverse flow in the inlet openings 3 of the chambers during combustion and detonation. The scattering elements may be tapering / expanding nozzles, porous plates, surface irregularities, or other geometric or aerodynamic elements in some embodiment. In one embodiment, moving parts in the air stream are not used to control combustion.

In one of the operating modes shown in FIGS. 2-7, when the combustion chamber 8 and detonation chamber 9 are substantially filled with the required volume of the air-fuel mixture, the fuel injection process is stopped. After a certain delay, igniters 10 are activated and combustion is initiated. The flame front 11 in the combustion chamber initially has a substantially spherical shape, as shown in FIGS. 2 and 3. As the combustion continues, the flame front expands, moving through the non-combustible mixture 12. As the heat of combustion is generated, the flame front accelerates to high speeds due to heat generation in limited volume. The flame acceleration can be increased by the use of turbulators, for example, Schepkin spirals or similar devices. The flame speed increases until the Chapman-Jouguet condition (C-J) is reached, after which the flame front moves at a supersonic constant speed. The flame front under this condition is connected (coupled) with a compression shock wave, which increases the pressure and temperature of the combustion products during the detonation process in a constant volume. Condition C-J determines the peak values of detonation pressure and flame velocity and depends on the type of fuel, detonating mixture, pressure and temperature. Thus, detonation leads to an increase in pressure and temperature of the combustion products 15. The pressure of the gaseous products of combustion is higher than the pressure of the air in the intake part. Therefore, the shock waves 16 propagate to the input of the combustion device, as shown in FIG. 3. If there are several combustion chambers at each detonation, several shock waves propagate simultaneously. Therefore, these shock waves converge in the intake manifold 4, as shown in FIG. 6. The convergence of shock waves and scattering elements in the intake manifold 4 reduce the back pressure; Thus, the pressure in the detonation tube increases with a significant reduction in the effects of back pressure on the inlet flow. This causes an increase in pressure in the detonation tube, which leads to high axial forces acting on the thrust plate 17 in thrust applications or to high pressures in the outlet of the combustion device to perform work and generate energy by the turbine. The air inlet opening 5 can be made with elements that minimize back pressure on the air supply pipe.

The detonation tubes can have independent exits or, in the embodiment of FIG. 8, the exits of two or more detonation tubes 18 can be connected to a combined nozzle nozzle 19, forming one exhaust port 20. Shock waves are directed to the exhaust nozzle, which can be opened into the environment (to create traction) or mounted with an expander to create mechanical power. When the detonation is completed, the pressure in the combustion chamber begins to drop and air enters the combustion device for the purge process. After the purge process is completed, fuel injection is again initiated for the next detonation cycle.

A combustion device with pulse detonation is shown in one embodiment with two or more detonation nozzles (tubes). All detonation tubes can be activated substantially simultaneously.

Each detonation tube 7 is fed by its own combustion chamber 8, and the individual pipes 7 are designed so that their shock waves interact, minimizing the reverse flow in the intake manifold 4 during the detonation stage with high pressure.

In one embodiment, the air inlet openings 3 to each combustion chamber 8 are configured so that minimal back pressures are transmitted to the air inlet 5.

Outlets 2 of detonation tubes 7 can be connected to one outlet 20, as shown in FIG. 8, or to multiple exits, as shown in FIGS. 1-6. The detonation output can be in the environment (in applications for creating traction) or on one or more turbines to create power on the shaft.

There are three relevant patents that disclose the valveless operation of pulse detonation devices. Two of these combustion devices are only controlled by the ignition system, since they lack fuel injection control. Therefore, in such combustion devices, there is a continuous flow of air and fuel and it is not possible to efficiently purge the combustion products before the next fuel injection cycle. One idea disclosed in United Technologies (US No. 6,584,765), incorporated herein by reference, is to use angled air and fuel inlets to propel the mixture toward the spark plug located at the closed end of the combustion device. In addition, a rotating disk was used to inject air and fuel. But although this invention is called a “valveless” pulse detonation engine (PDE, pulse detonation engine), a valve is used in the inlet. This invention is operable at an outlet pressure close to vacuum, and is proposed to create thrust in spacecraft. Another idea is disclosed in Shimo et al. (US application 2007/0245712), also incorporated into this description by reference; this application proposes a combination of a porous plate, a large combustion chamber and a long inlet to reduce back pressure in the supply pipe.

U.S. General Electric Patent No. 6,666,018 B2, also incorporated herein by reference, provides a hybrid pulsed detonation engine coupled to a conventional jet engine. The patent claims that "in one embodiment, the system is controlled by a valveless continuous detonation system that includes a pre-combustion device." This is indicated in reference to a two-stage pulse detonation combustion device proposed in US Pat. No. 6,983,586. In this invention, pulse detonation devices are used in a conventional jet engine as primary or amplification combustion devices. The patent describes multi-tube, self-contained pulsed detonation devices that operate independently. Each combustion device operates independently of other combustion devices, and the knock effect in one combustion device does not affect other detonation pipes. This idea is significantly different from the idea presented in this application, in which all detonation tubes interact with each other. Other new features of this application include a new fuel-air mixing device, an air pre-heating device, and an air intake manifold.

The device proposed in this document differs from the previous designs in several of the following features. The proposed combustion device 1 is a multi-tube combustion device with pulse detonation. The detonation tubes 7 work in phase, and detonation is carried out simultaneously in all detonation chambers 9. In the known multi-tube combustion devices, detonation in individual detonation tubes is carried out, as a rule, with time diversity in order to reduce impacts and power fluctuations during operation.

In one embodiment, the air inlet hole 5 is distributed to several detonation chambers 9. The back pressure waves exiting through the detonation tubes 7 to the chamber air inlet holes 3 are attenuated by the scattering elements, and, in addition, are guided so that they converge in one zone in the intake manifold 4 and extinguished each other. This damping of detonation pulses reduces the effect of back pressure on input 5. Several previous patents on multi-tube combustion devices describe the unconnected inlets of individual detonation tubes so that each flame tube can operate independently of the other tubes.

In the proposed combustion device 1, in at least one of the embodiments, a porous plate or other scattering elements can be used to reduce the effect of the detonation back pressure on the air inlet 3. This effect is provided by narrowing / expanding nozzles, as well as the convergence and interaction of pressure pulses. Several prior patents suggest the use of a mechanical valve; however, there are a number of patents for a valveless combustion device with pulse detonation, for example, US patent application 2007/0245712 A1, incorporated herein by reference, describes valveless operation. This known design requires the use of a porous plate to reduce the impact of the shock wave on the upstream pipe and suction pipe.

The flame tube may be curved, curved, spiral, or otherwise non-linear, as shown in FIGS. 9-12. In one embodiment, the flame tube may be made of several U-shaped tubes connected together. In another embodiment, the flame tube may be in the form of a spiral. The bending radius of the combustion device must be greater than the diameter of the combustion chamber to maintain the speed of propagation of the detonation wave during operation. The curvature of the combustion chamber may not exclude the need for turbulators (e.g., Shchepkin spirals), and flame propagation accelerators can be included to reduce the distance from combustion to detonation (DDT, deflagration-to-detonation transition). It may be desirable for the circuits of flame propagation accelerators to follow the contours of the combustion device.

In the exhaust port of the combustion device, upstream of the inlet of the expander, exhaust nozzles may be used to increase the pressure of the stream as it enters the expander. Such a nozzle may have different cross-sectional profiles (tapering or expanding), depending on the expander used and the workload. So, for example, if high pressure is required, an expanding nozzle is used to reduce the flow rate and increase the gas pressure at the inlet of the expander.

The combustion device can be designed with one or more combustion and detonation chambers, and all paired combined combustion / detonation chambers operate as autonomous combustion systems with separate outputs that are connected and directed to the turbine. In this embodiment, the combustion processes in the detonation chambers can be carried out rather sequentially than simultaneously, which provides a more uniform supply of energy to the turbine.

FIGS. 1-12 show other types of multi-tube pulse detonation combustion devices. Air and fuel can mix upstream and enter the combustion chambers through the inlet pipes. After injecting the required amount of the combustible mixture, the fuel injectors are closed, and in the combustion chambers ignition starts from several igniters simultaneously. The igniter may be a spark plug, a laser, a plasma, or other igniter. The flame front is accelerated by passing through flame propagation accelerators in detonation tubes. The flame propagation accelerator can be any element that creates turbulence in the detonation tube. The outputs of the two flame tubes can be independent (as shown in FIGS. 1-3) or combined (as shown in FIGS. 4-6). Shock waves and combustion products exit through the outlet at high pressure and at high temperature. The combustion device is then blown and the next detonation cycle is started.

Figure 1 shows an embodiment of a combustion device with six round detonation chambers. This engine proposal is not intended to be a limited embodiment with six detonation chambers, and includes embodiments with two or more detonation chambers.

FIGS. 2-7 show a cross section of a combustion device in one embodiment, as well as a detonation process and a shock / flame propagation front in a combustion device.

FIG. 8 shows an embodiment of a combustion device with a combined nozzle and one outlet. The exits of the flame tubes can be connected together to form one integrated outlet for all the flame tubes of the combustion device. Since in one embodiment all the detonation chambers operate substantially simultaneously, for an output nozzle without an accelerating effect, the cross-sectional area of a single outlet may be equal to the sum of the cross-sections of all detonation chambers. However, the output may include a nozzle kit (tapering or expanding) that adjusts the output conditions (pressure, temperature and speed) depending on the operating point of the combustion chamber. For example, in FIG. 9, the cross section of the outlet nozzle 22 may be less than the total cross-sectional area of the four combustion chambers 28, forming a combined tapering nozzle 22.

In one embodiment of a multi-tube valveless combustion device 21, detonation chambers are connected to each other via an intake manifold 24, as shown in FIG. 12, and a change in pressure in one combustion chamber 28 will affect other detonation chambers.

The detonation tube 27 of the pulse detonation device, or the multi-tube combustion device 21 may be curved or curved, as shown in FIGS. 9-12. Where possible, the elements of the curvilinear structure shown in FIGS. 9-12 are indicated by the same numbers as in the previous embodiments, with the number 2 in front. For example, in the curvilinear embodiment, the detonation chambers are indicated by the number 27, while in the previous embodiments, the number 7 was used to designate each detonation chamber. The detonation chamber 27 of the multi-tube combustion device may be curved, bent, or bent at an angle. The experiments confirmed that the detonation wave can travel along the non-linear axis of the detonation chamber with a small curvature of the bends 31. Thus, the combustion chamber 28 can be curved, curved or otherwise non-linear to create a more compact design. Such a curved design is applicable to single-pipe or multi-pipe combustion devices.

While the embodiment shown in FIGS. 9-12 shows a single combined outlet functionally similar to the previous embodiment shown in FIG. 7, for alternative applications, the same curved device of detonation tubes 27 can be used in the device with multiple outlets as shown in FIG. 1.

Although the present invention is illustrated by a description of several embodiments, and although these illustrative embodiments are described in detail, the description is not intended by the applicant to narrow or in any way limit the scope of the present invention to these details. The specialist can easily create additional benefits and introduce modifications that do not depart from the scope of the attached claims. Thus, the present invention in its broad interpretation is not limited to specific details, characteristic devices and methods, as well as illustrative examples shown and described. Accordingly, deviations from such details are possible without departing from the meaning or scope of the general idea of the invention.

Claims (22)

1. A valveless multi-tube engine with pulse detonation, containing detonation pipes, each of which has an independent discharge outlet, while the said detonation pipes are connected to each other in a common inlet of the air-fuel mixture with simultaneous detonation of the air-fuel mixture in the detonation pipes while the common inlet of the air-fuel mixture is made with the possibility of directing the return shock waves at each other and ensuring a minimum return d erosion caused by detonation of the air-fuel mixture. 2. The engine according to claim 1, characterized in that it contains turbulators located in detonation tubes and configured to increase the speed of flame propagation. 3. The engine according to claim 2, characterized in that the turbulators contain a cochlea along the length of the detonation chamber section of each detonation tube. 4. The engine according to claim 1, characterized in that to provide higher resistance to the propagation of the wave backward compared to the propagation of the wave forward, it contains geometric elements located in the inlet openings of the combustion chambers, selected from the group including tapering nozzles, expanding nozzles, porous plates or hydraulic diodes. 5. The engine according to claim 1, characterized in that the common air inlet opening has an air valve. 6. The engine according to claim 1, characterized in that the exhaust openings of all detonation pipes are connected to a single exhaust opening. 7. The engine according to claim 6, characterized in that the detonation tube output is connected to a turbine configured to generate mechanical power as a result of the combustion process in a valveless multi-tube engine with pulse detonation. 8. The engine according to claim 7, characterized in that the turbine is a volumetric type movement device. 9. The engine according to claim 1, characterized in that the detonation tubes are made non-linear. 10. The engine according to p. 9, characterized in that the non-linear detonation tubes contain elements in the form of an arc with an angle essentially equal to 180 °. 11. The engine under item 9, characterized in that it contains a combined tapering nozzle nozzle. 12. A valveless multi-tube engine with pulse detonation, comprising detonation tubes, each of which has an independent outlet, said detonation tubes being connected to each other in a common air inlet opening to simultaneously detonate the air-fuel mixture in the detonation tubes, and each detonation the pipe contains at least one fuel injector hydraulically connected to the detonation pipe for supplying fuel to it, while the common air inlet opening is made but with the possibility of shock waves reverse direction to each other and ensure a minimum back pressure caused by the detonation of the air-fuel mixture. 13. The engine according to p. 12, characterized in that it contains turbulators located in detonation tubes and configured to increase the speed of propagation of the flame. 14. The engine according to claim 13, characterized in that the turbulators contain a cochlea along the length of the detonation chamber section of each detonation tube. 15. The engine according to p. 12, characterized in that in order to provide higher resistance to the propagation of the wave backward compared with the propagation of the wave forward in the inlet openings of the combustion chambers, geometric elements are provided in the form of narrowing or expanding nozzles, porous plates or hydraulic diodes. 16. The engine of claim 12, wherein the common air inlet is equipped with an air valve. 17. The engine according to p. 12, characterized in that the exhaust holes of all detonation pipes are connected to a single exhaust hole. 18. The engine according to claim 17, characterized in that the detonation tube output is connected to the turbine with the possibility of generating mechanical power using combustion products. 19. The engine according to claim 18, characterized in that the turbine is a volumetric type movement device. 20. The engine according to p. 12, characterized in that the detonation tubes are made non-linear. 21. The engine according to p. 20, characterized in that the non-linear detonation tubes are made in the form of an arc with an angle essentially equal to 180 °. 22. The engine according to p. 20, characterized in that it contains a combined tapering nozzle nozzle, converging in one exhaust hole.

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