CN119532759A - Multi-fuel combustion chamber head and control method of multi-fuel combustion chamber - Google Patents

Abstract

A multi-fuel combustion chamber head allows for hydrogen loading or pure hydrogen combustion during some conditions. A control method of a multi-fuel combustion chamber can realize a low-pollution low-carbon combustion organization form. The multi-fuel combustion chamber head comprises a valve class, the valve class comprises a first air flow passage and a liquid fuel pipe, air provided by the first air flow passage and liquid fuel provided by the liquid fuel pipe are mixed in a premixing space, a second air flow passage extends at the periphery of the premixing space, an outlet is positioned at the downstream side of the premixing space, a swirler is omitted in the second air flow passage, an air pressurizing device is arranged in the second air flow passage so that air flows out of the outlet in an accelerating mode, and a hydrogen distribution pipe comprises a plurality of spray holes which are arranged to be transversely sprayed out of the downstream of the outlet of the second air flow passage relative to the air flow direction of the second air flow passage.

Description

Multi-fuel combustion chamber head and control method of multi-fuel combustion chamber

Technical Field

The present invention relates to a combustor, and more particularly, to a combustor head of a gas turbine or an aeroengine and a combustion control method of the combustor.

Background

The increased environmental awareness has made the reduction of pollutant emissions during combustion one of the major challenges in aircraft engine development. In order to achieve lower NOx emissions without increasing the concentration of tail gas carbon monoxide and unburned hydrocarbons, low-emission combustion forms such as lean premixed pre-vaporization and rich quenched lean combustion have been widely studied and used in gas turbines and aircraft engines. However, along with the proposal of the carbon neutralization target, the tail gas emission based on hydrocarbon fuel always contains CO ₂, which cannot meet the requirement of low-carbon combustion. Recently, combustion organizations based on sustainable and other fuels have been widely studied in aircraft engine combustors, with the main objective of further reducing carbon emissions while reducing traditional pollutant emissions (such as NOx).

Hydrogen combustion is one of the most environment-friendly combustion organization modes at present, has the problems of no combustion carbon emission and other combustion pollution products, and is a low-carbon fuel with great potential. However, hydrogen combustion also has the problems of difficult storage, high transportation cost per unit volume, too high combustion speed, high flame temperature and the like, which brings challenges to reasonably organizing combustion in the combustion chamber of the aeroengine. Meanwhile, traditional liquid fuels and sustainable fuels remain the main fuels of aircraft engines for a long time due to factors such as cost and risk of re-developing new combustors. Therefore, the design of the multi-fuel aeroengine combustion chamber capable of simultaneously combusting liquid fuel and hydrogen not only can effectively reduce carbon emission and pollutant products, but also can reduce the cost and risk of designing a new combustion chamber by utilizing the existing mature combustion chamber geometry.

Disclosure of Invention

It is an object of the present invention to provide a multi-fuel combustor head that allows for hydrogen loading or pure hydrogen combustion in some operating conditions.

Another object of the present invention is to provide a control method for a multi-fuel combustion chamber, which realizes a low pollution and low carbon combustion organization form.

According to one aspect of the invention, a multi-fuel combustion chamber head comprises a shift stage, wherein the shift stage comprises a first air flow passage and a liquid fuel pipe, air provided by the first air flow passage and liquid fuel provided by the liquid fuel pipe are mixed in a premixing space, a second air flow passage extends at the periphery of the premixing space, an outlet is positioned at the downstream side of the premixing space, a cyclone is omitted in the second air flow passage, an air pressurizing device is arranged in the second air flow passage so that air flows out of the outlet in an accelerating way, and a hydrogen distribution pipe comprises a plurality of spray holes which are arranged to spray transversely relative to the air flow direction of the second air flow passage at the downstream of the outlet of the second air flow passage.

In one embodiment, the air plenum includes a plenum section of the second air flow passage, a plurality of air baffles. The supercharging section of the second air flow passage extends to the outlet, the cross-sectional area of the flow passage is reduced along the air flow direction, and a plurality of air separation plates are circumferentially distributed at intervals in the supercharging section.

In one embodiment, the premixing space is defined by an inner surface of the venturi.

In one embodiment, two air baffles and one spray hole are arranged in a one-to-one correspondence, so that air flow passing through the two air baffles is accelerated to flow through the corresponding spray hole.

In one embodiment, the distance between the nozzle orifice and the end wall facing the flame chamber is 1-5mm.

In an embodiment, the distance between the nozzle orifice and the end wall of the structure defining the premixing space is 1-5mm.

In an embodiment, the liquid fuel pipe is connected to a centrifugal nozzle, the centrifugal nozzle is used for generating liquid mist from liquid fuel and enabling the liquid mist to strike a wall surface of the premixing space, and the first air flow passage is provided with a cyclone so as to enable air and atomized liquid fuel to be fully mixed.

A control method of a multi-fuel combustion chamber according to another aspect of the present invention includes the steps of:

providing a multi-fuel combustor comprising any of said multi-fuel combustor heads, said multi-fuel combustor heads further comprising a main combustion stage surrounding said value shift;

when the combustion chamber ignites, only the duty-class flame is started, and in order to improve the ignition performance of the combustion chamber, hydrogen-doped or pure hydrogen combustion is adopted;

when the engine is in a low-thrust working condition, only the duty stage is started, and hydrogen-doped or pure hydrogen combustion is adopted;

when the engine is in a medium-high thrust working condition, the valve class flame and the main combustion stage flame are simultaneously started, the valve class flame is burnt by pure hydrogen or hydrogen, and the main combustion stage flame is burnt by pure liquid.

According to the embodiment of the invention, the staged combustion of the duty-stage hydrogen-doped/pure hydrogen combustion and the main combustion stage liquid fuel combustion is realized by introducing hydrogen into the class of the combustion chamber value, and the stable combustion with low pollution and low carbon can be formed by flexibly changing and adjusting the equivalent ratio and the fuel distribution of the combustion chamber. The method is different from the characteristics that the traditional radial staged combustion is liquid fuel, and the method is characterized in that a cyclone is omitted in an air flow channel where a hydrogen transverse jet flow is located, an air partition plate is arranged, the mixing of hydrogen and air is accelerated, the tempering risk is reduced, the hydrogen-doped/pure hydrogen combustion of a class is formed, the existing liquid fuel such as aviation kerosene and other sustainable alternative fuels are utilized to form main combustion stage flames, and the low-pollution and low-carbon combustion organization form is achieved.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings and embodiments, in which:

FIG. 1 is a schematic illustration of a multi-fuel combustor.

FIG. 2 is a cross-sectional view of a multi-fuel combustion chamber head.

FIG. 3 is a perspective view of a multi-fuel combustion chamber head.

FIG. 4 is a perspective view of a shift of a multi-fuel combustor head.

Detailed Description

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation, not limitation, of the invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Accordingly, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to represent the location or importance of the respective components.

The terms "upstream" and "downstream" refer to relative directions with respect to fluid flow in a fluid path. For example, "upstream" refers to the direction from which fluid flows and "downstream" refers to the direction in which fluid flows.

As shown in fig. 1, the multi-fuel combustor includes a combustor head 34 that includes a centrally located pilot stage and a main stage disposed about the pilot stage to form a radial staged combustion, i.e., a combustion pattern that utilizes air or fuel or the like to form zones at radially different spatial locations. The staged combustion is adopted, and the proportion of the valve class fuel and the main combustion class fuel can be flexibly adjusted according to different working conditions of the aero-engine.

As shown in fig. 2, the duty stage includes a first air flow passage 11 and a liquid fuel pipe 1, and air supplied from the first air flow passage 11 and liquid fuel supplied from the liquid fuel pipe 1 are mixed in a premixing space 16. The class further comprises a second air flow channel 12 and a hydrogen distribution pipe 3. The second air flow passage 12 extends at the outer periphery of the premixing space 16, and the outlet is located at the downstream side of the premixing space 16, and the cyclone is eliminated and an air pressurizing device is provided in the second air flow passage 12 to accelerate the air flowing out from the outlet. The hydrogen distribution pipe 3 is connected to the nozzle holes 4, and the nozzle holes 4 are arranged downstream of the outlet of the second air flow passage 12 to be ejected transversely with respect to the air flow direction of the second air flow passage 12. In the following, the air flow passage has an annular structure in the combustion chamber head and the tube has an elongated cylindrical structure in the combustion chamber head.

As shown in fig. 1, after the air 21 enters the combustion chamber through the diffuser, part of the air 24 enters the head of the combustion chamber to directly participate in combustion, part of the air 22 flows through the inner annular cavity of the combustion chamber to form cooling air 25, and part of the air 23 flows through the outer annular cavity of the combustion chamber to form cooling air 25. The cooling air 25 enters partially into the interior of the cartridge, cools the cartridge wall, and then flows along with the hot gas 26 to the downstream high pressure turbine. As shown in fig. 2, the air 24 entering the head of the combustion chamber is again split into shift level air 7 entering the shift level and main combustion level air 8 entering the main combustion level. The on-duty air 7 is split into two streams, one stream flowing through the first air flow passage 11 and entering the premixing space 16, where it mixes with the fuel supplied from the liquid fuel pipe 1. The other air enters the air flow channel 12 without the cyclone, is accelerated by the air pressurizing device and is mixed with the hydrogen sprayed out from the downstream spray hole 4. By eliminating the cyclone in the air flow channel where the hydrogen transverse jet flow is located and arranging the air pressurizing device, the mixing of the hydrogen and the air is accelerated, the tempering risk is reduced, and pure hydrogen combustion can be formed. In the shift of the hydrogen loading combustion, on the one hand, the hydrogen in the hydrogen distribution pipe 3 is mixed with the air in the second air flow passage 12 and enters the combustion chamber, and on the other hand, the air via the cyclone 10 is mixed with the liquid mist 6 generated by the centrifugal nozzle 32 and enters the combustion chamber. The mixed gas in the two aspects has a certain mutual mixing relation between the end face 14 and the end face 15, and is further mixed at the downstream, and the duty-class flame is the mixed flame containing the hydrogen transverse jet flow and the liquid fuel centrifugal nozzle, so that the low-carbon-emission duty-class flame is formed.

One embodiment of the air plenum includes a plenum section of the second air flow passage 12 that extends upwardly to the outlet of the second air flow passage 12 and reduces in cross-sectional area along the direction of air flow as shown in fig. 2. The air plenum also includes a plurality of air baffles 33 circumferentially spaced within the plenum section. The plenum section and air baffle 33 together compress the air flow and thus boost the pressure by limiting the cross-sectional flow area of the flow path.

With continued reference to FIG. 2, the premix space 16 is defined by the inner surface of the venturi. The venturi effect of pressurizing and then depressurizing the fluid is beneficial to fully mixing the liquid fuel and the air.

In the preferred embodiment, two air baffles 33 and one nozzle 4 are disposed in a one-to-one correspondence, so that the air flow passing through the two air baffles 33 is accelerated to flow through the corresponding nozzle 4, thereby enhancing the supercharging effect of the air. As shown in fig. 3 and 4, the air baffle plates 33 and the injection holes 4 are each arranged in a ring shape, and thus the number of the air baffle plates 33 may be set to be the same as that of the injection holes 4, the air baffle plates 33 being offset at an angle in the circumferential direction with respect to the injection holes 4, or both being offset in the circumferential direction.

In one embodiment, the distance between the nozzle orifice 4 and the end wall 15 facing the flame chamber is 1-5mm.

In a further embodiment, the distance between the nozzle orifice 4 and the end wall of the structure defining the premixing space 16 is 1-5mm. For example in figure 2 the distance between the orifice 4 and the end wall 14 of the venturi is 1-5mm.

In a more specific embodiment, the holes of the spray 4 have a diameter of 0.3-2mm and a number of holes of 12-60, and are uniformly distributed along the circumference of the class wall.

With continued reference to fig. 2, the liquid fuel pipe 1 is connected to a centrifugal nozzle 32, the centrifugal nozzle 32 is used for generating liquid mist 6 from liquid fuel and making the liquid mist 6 strike against the wall surface of the premixing space 16, and the first air flow passage 11 is provided with a cyclone 10 so as to fully mix air with atomized liquid fuel.

The cyclone 10 is preferably a high swirl number cyclone, e.g., greater than 0.7 swirl number, to create a strong reflux zone velocity shear, allowing for adequate mixing of air and liquid fuel.

As shown in fig. 1, the fuel pipe 29 contains two fuel paths, a liquid fuel transport pipe 30 and a hydrogen fuel transport pipe 31. The liquid fuel of the pipe 30 enters the centrifugal nozzle 32 of the valve class through the fuel pipe 1 to generate liquid mist 6, the liquid mist 6 impacts the venturi wall surface 16 to form a liquid film, and the liquid film is sheared by the rotational flow of the first air flow channel 11 and the air flow of the second air flow channel 12 at the venturi outlet end surface 14, so that the liquid film is gradually broken into liquid filaments and further broken into small liquid droplets. The hydrogen in the tube 31 enters the hydrogen transverse jet orifice 4 through the hydrogen distributing tube 3, and the generated hydrogen transverse jet 18 is further mixed with the droplet group 17 downstream of the duty stage to enter the combustion chamber, so as to form the duty stage flame 28.

The main combustion stage air 8 passes through the main combustion stage cyclone 9 and is fully mixed with the liquid fuel generated by the transverse jet fuel nozzle 5 and enters the combustion chamber. The liquid fuel of the pipe 30 passes through the fuel pipe 2 and enters the main combustion stage spray hole 5 to form a transverse spray mist spray 19, and the transverse spray mist spray impinges on the wall surface 13, is fully mixed with the main combustion stage air in the main combustion stage passage 20 and enters the combustion chamber to form a main combustion stage flame 27. This facilitates the formation of a lean low pollution main stage flame as the main stage fuel is blended with air in the main stage passage by the liquid transverse jet.

In one embodiment, the diameter of the main combustion stage spray holes 5 is 0.5-2mm, the number of holes is 12-24, and the holes are uniformly distributed along the circumference of the main combustion stage air flow channel and are 5-15mm away from the outlet end face 15 of the burner.

The class-number centrifugal nozzle and the main fuel grade fuel may be conventional aviation kerosene or other sustainable alternative fuels. The hydrogen in the hydrogen distribution pipe 3 may be pure hydrogen or a fuel rich in hydrogen element.

As shown in fig. 1 and fig. 2, the duty-class flame 27 formed by mixing the duty-class hydrogen 18 and the liquid fuel 17 is arranged in the middle of the combustion chamber, and according to different working conditions of the combustion chamber, the hydrogen adding proportion of the duty-class flame can be flexibly adjusted, and the duty-class can be burnt by pure liquid fuel or pure hydrogen. The main combustion stage flame 28 formed by the main combustion stage fuel 19 is in the circumferential direction of the duty stage flame 27. When only the value class is started, the value class can be the hydrogen loading and pure hydrogen combustion, and the mass ratio of the hydrogen loading is adjusted to be in the range of 0-100%. When the pilot and main stage flames are simultaneously on, the hydrogen mass fraction is less than 25% of the total fuel mass. By flexibly adjusting the duty ratio of the hydrogen and the liquid fuel, the phenomena of backfire, flameout, combustion oscillation and the like of the combustion chamber are avoided, and the low-carbon low-pollution stable combustion is formed.

In one embodiment, the control method of the multi-fuel combustion chamber meets different working conditions and emission requirements of the engine by flexibly adjusting the proportion of the duty-stage flame and the main combustion-stage flame. When the combustion chamber ignites, only the duty-class flame is started, and in order to improve the ignition performance of the combustion chamber, hydrogen-doped or pure hydrogen combustion is adopted. When the engine is in a low-thrust working condition, the low working condition comprises a sliding working condition or a working condition similar to the thrust required by the working condition, the combustion chamber is only opened for a class, and hydrogen-doped or pure hydrogen combustion can be adopted. When the engine is in a medium-high thrust working condition, the medium-high thrust working condition comprises a working condition of taking off, cruising and landing or a working condition similar to the thrust required by the working conditions, the on-duty flame and the main combustion flame are simultaneously started, the on-duty flame can adopt pure hydrogen or hydrogen-doped combustion, and the main combustion flame is pure liquid combustion.

While the invention has been described in terms of preferred embodiments, it is not intended to be limiting, but rather to the invention, as will occur to those skilled in the art, without departing from the spirit and scope of the invention. Therefore, any modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention fall within the protection scope defined by the claims of the present invention.

Claims (8)

1. The utility model provides a many fuel combustion chamber head, includes the class, the class includes first air runner and liquid fuel pipe on duty, air that first air runner provided and liquid fuel pipe provided mix in premixing space, its characterized in that, the class still includes:

A second air flow passage extending from the outer periphery of the premixing space and having an outlet at the downstream side of the premixing space, wherein the second air flow passage is provided with an air pressurizing device without a cyclone so as to accelerate the air flowing out from the outlet, and

And the hydrogen distribution pipe comprises a plurality of spray holes which are arranged to spray transversely relative to the air flow direction of the second air flow channel at the downstream of the outlet of the second air flow channel.

2. The multi-fuel combustor head according to claim 1 wherein said air plenum means comprises:

A pressurizing section of the second air flow path extending to the outlet, the flow path having a reduced cross-sectional area in the direction of air flow, and

And the air separators are circumferentially distributed at intervals in the pressurizing section.

3. The multi-fuel combustor head according to claim 1 or 2 wherein said premixing space is defined by the inner surface of a venturi.

4. The multi-fuel combustor head according to claim 2 wherein two of said air baffles and one of said orifices are arranged in a one-to-one correspondence such that air flow through both of said air baffles is accelerated through the corresponding one of said orifices.

5. The multi-fuel combustion chamber head of claim 1 or 2 wherein the distance between the nozzle orifice and the end wall facing the flame chamber is 1-5mm.

6. The multi-fuel combustor head according to claim 1 or 2 wherein the distance between the nozzle orifice and the end wall of the structure defining the premixing space is 1-5mm.

7. The multi-fuel combustor head according to claim 1 or 2 wherein said liquid fuel pipe is connected to a centrifugal nozzle for generating a liquid mist from the liquid fuel and causing the liquid mist to impinge on a wall surface of said premixing space, said first air flow path being provided with a swirler for sufficiently mixing air with the atomized liquid fuel.

8. A method of controlling a multi-fuel combustion chamber, comprising:

providing a multi-fuel combustor comprising the multi-fuel combustor head of any one of claims 1 to 7, said multi-fuel combustor head further comprising a main combustion stage surrounding said value shift;

when the combustion chamber ignites, only the duty-class flame is started, and in order to improve the ignition performance of the combustion chamber, hydrogen-doped or pure hydrogen combustion is adopted;

when the engine is in a low-thrust working condition, only the duty stage is started, and hydrogen-doped or pure hydrogen combustion is adopted;

when the engine is in a medium-high thrust working condition, the valve class flame and the main combustion stage flame are simultaneously started, the valve class flame is burnt by pure hydrogen or hydrogen, and the main combustion stage flame is burnt by pure liquid.