Combustion chamber head, combustion chamber, gas turbine

Abstract

The present invention discloses a combustion chamber head, a combustion chamber, and a gas turbine, relating to the technical field of aero gas turbines. The combustion chamber head includes a body, on which a plurality of micro combustion holes are provided. The air flow channels of the micro combustion holes penetrate through the body. The upstream of the air flow channels of the micro combustion holes is a contraction section, and the downstream is an expansion section; a conveying pipeline for supplying hydrogen fuel to the micro combustion holes; and a plurality of nozzles, which correspond to the micro combustion holes one by one. The nozzles are close to the outlets of the corresponding micro combustion holes and connect the conveying pipeline with the micro combustion holes. The plurality of micro combustion holes achieve micro hole lean combustion, which can increase the contact area between fuel and air and reduce the emission of NOX. The air flow channels of the micro combustion holes adopt a shape of first contraction and then expansion. By utilizing the fluid flow characteristics, enough space is left for the recirculation zone, effectively preventing flashback.

Description

Technical Field

[0001] The present invention relates to the technical field of aero gas turbines, and particularly relates to a combustor head, a combustor, and a gas turbine. Background Art

[0002] After hydrogen fuel burns, only water vapor is produced. Compared with traditional fossil fuels, it can achieve true zero carbon dioxide emissions. However, the flame temperature during hydrogen fuel combustion is higher than that of aviation kerosene, and more NOx emissions are likely to be generated during combustion in air. The temperature of a traditional aero gas turbine combustor will exceed 2000°C, and the equivalence ratio is close to 1, resulting in a relatively high level of NOx formation. For a hydrogen-fueled aero engine, the temperature of its combustor is even higher, causing greater NOx emission pollution.

[0003] The ideal way to control NOx emissions is to adopt premixed combustion. However, hydrogen fuel is a gas with a faster flame propagation speed and is prone to autoignition flashback, so non-premixed combustion needs to be adopted. But adopting non-premixed combustion is likely to cause local hot spots, resulting in an increase in NOx emissions.

[0004] Compared with aviation kerosene, the lean blowout equivalence ratio of hydrogen fuel is lower, and at the same time, the combustion heat of hydrogen fuel is higher, and the main combustion zone of its combustor can operate in a region with a lower equivalence ratio. However, when the chemical equivalence ratio is relatively low, the heat release rate fluctuation of the flame itself increases, which is easily coupled with the thermoacoustic characteristics of the combustor, inducing combustion instability and generating a relatively large pressure value, which poses a great challenge to the strength and service life of the engine. For hydrogen fuel combustion, the adiabatic flame temperature increases, the laminar flame speed increases, the ignition delay time decreases sharply, and the flame combustion oscillation level is severely aggravated, which has a great impact on the combustor. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects in the prior art and provide a combustor head, a combustor, and a gas turbine.

[0006] The present invention solves the above technical problem through the following technical solutions:

[0007] A combustor head includes a body, and the following are provided on the body: a plurality of micro combustion holes, the gas flow channels of the micro combustion holes penetrate through the body, the upstream of the gas flow channels of the micro combustion holes is a contraction section, and the downstream is an expansion section; a delivery pipeline for supplying hydrogen fuel to the micro combustion holes; and a plurality of nozzles, the nozzles correspond to the micro combustion holes one by one, and the nozzles are close to the outlets of the corresponding micro combustion holes and connect the delivery pipeline and the micro combustion holes.

[0008] In this solution, multiple micro-combustion holes are provided on the main body of the combustion chamber to achieve micro-hole lean combustion, which can increase the contact area between fuel and air, reduce the emission of NOX. Moreover, the air flow channel of the micro-combustion hole adopts a shape that first contracts and then expands. Utilizing the fluid flow characteristics, the upstream contraction section is used to accelerate the oncoming flow to reduce the risk of flashback, and the downstream expansion section can ensure the outward expansion of the flame surface, leaving enough space for the recirculation zone. That is, the flow channel structure with an upstream contraction section and a downstream expansion section can effectively prevent flashback.

[0009] Preferably, the normal direction of the nozzle is 90° to the flow direction of the air flow in the micro-combustion hole.

[0010] In this solution, the normal direction of the nozzle is set at 90° to the flow direction of the air flow in the micro-combustion hole, so that the hydrogen fuel ejected from the nozzle enters the micro-combustion hole in a transverse jetting manner, and quickly mixes and burns with the air in the air flow channel of the micro-combustion hole, eliminating local overheating points and reducing the gas temperature, thereby being able to suppress the emission of Nox.

[0011] Preferably, multiple circles of the micro-combustion holes are arranged along the circumference of the main body, and multiple circles of the micro-combustion holes are distributed in multiple layers on the main body.

[0012] In this solution, by arranging multiple circles of combustion holes on the main body, and multiple circles of the micro-combustion holes are arranged in multiple layers, the flame in the combustion zone can be split into a large number of small flames, increasing the contact area between fuel and air.

[0013] Preferably, there are several conveying pipelines, and each conveying pipeline is arranged between adjacent two layers of the micro-combustion holes to supply hydrogen fuel to the micro-combustion holes on both sides of it.

[0014] In this solution, the micro-combustion holes are distributed on both sides of the conveying pipeline, and hydrogen fuel is provided to the micro-combustion holes on both sides through the conveying pipeline. The micro-combustion holes on both sides share one conveying pipeline, simplifying the structure.

[0015] Preferably, a fuel main pipe is further provided on the main body, and multiple conveying pipelines are connected to the fuel main pipe in a parallel connection manner to distribute hydrogen fuel to several conveying pipelines.

[0016] In this solution, multiple conveying pipelines are connected in parallel and communicate with the fuel main pipe to achieve hierarchical supply of hydrogen fuel, and different equivalence ratios can be adjusted on different layers, so as to more flexibly avoid some natural frequencies that cause combustion oscillations.

[0017] Preferably, a cooling gas slit and cooling holes are further provided on the body. The cooling holes communicate with the cooling gas slit, and the outlets of the cooling holes are located between adjacent two layers of the micro combustion holes. The cooling gas enters the head of the combustion chamber through the cooling gas slit and flows into the combustion zone through the cooling holes; and / or, adjacent two layers of the micro combustion holes are arranged staggeredly.

[0018] In this solution, there are a cooling gas slit and cooling holes. The cooling gas enters the head of the combustion chamber through the cooling gas slit and flows into the combustion zone through the cooling holes. The cooling gas not only cools the head of the combustion chamber, but also, since the cooling holes are located between adjacent two layers of the micro combustion holes, the cooling gas can also play a role in separating each small flame, effectively preventing the flames from being in series; the adjacent two layers of the micro combustion holes are arranged staggeredly, which can further reduce or prevent the flame roots of the adjacent two layers of micro combustion holes from being in series.

[0019] Preferably, a boss is provided downstream of the airflow of the micro combustion holes.

[0020] In this solution, a boss is provided downstream of the airflow of the micro combustion holes. A larger recirculation zone can be formed downstream through the boss, and the flame can be stabilized better.

[0021] Preferably, the outlet cross-section of the micro combustion holes is arch-shaped.

[0022] In this solution, the outlet cross-section of the micro combustion holes is set as arch-shaped, which is beneficial for the cooling gas for cooling the head of the combustion chamber to enter through the radially distributed annular cooling gas slit.

[0023] The present invention also provides a combustion chamber, including a flame tube, and further including the aforementioned head of the combustion chamber, and the head of the combustion chamber is located at the end of the flame tube.

[0024] The present invention also provides a gas turbine, which includes the aforementioned combustion chamber.

[0025] The positive and progressive effects of the present invention are as follows: Multiple micro combustion holes are provided on the body of the combustion chamber to achieve micro-hole lean combustion, which can increase the contact area between fuel and air, reduce the emission of NOX, and the airflow channel of the micro combustion holes adopts a shape that first contracts and then expands. Utilizing the fluid flow characteristics, the upstream contraction section is used to accelerate the oncoming flow to reduce the risk of flashback, and the downstream expansion section can ensure the outward expansion of the flame surface, leaving enough space for the recirculation zone, that is, the flow channel structure with an upstream contraction section and a downstream expansion section effectively prevents flashback. Description of the Drawings

[0026] Figure 1 It is a sectional view of a combustion chamber according to an embodiment of the present invention.

[0027] Figure 2 It is a partial view of the head of the combustion chamber according to an embodiment of the present invention.

[0028] Figure 3 This is a partial cross-sectional view of the combustion chamber head according to an embodiment of the present invention.

[0029] Figure 4 is Figure 3 a partially enlarged view at position A in

[0030] Figure 5 This is another partial cross-sectional view of the combustion chamber head according to an embodiment of the present invention.

[0031] Description of reference numerals

[0032] Combustion chamber head 1

[0033] Body 2

[0034] Micro combustion hole 3

[0035] Delivery pipe 4

[0036] Nozzle 5

[0037] Fuel manifold 6

[0038] Cooling gas slit 7

[0039] Cooling hole 8

[0040] Boss 9

[0041] Combustion chamber 10 Detailed implementation manners

[0042] The present invention will be further described below by way of embodiments, but the present invention is not limited to the scope of the described embodiments.

[0043] The present invention provides a combustion chamber head, a combustion chamber, and a gas turbine. As Figure 2-5As shown in the figure, the combustion chamber head includes a body 2, on which a plurality of micro combustion holes 3, a conveying pipeline 4, and a plurality of nozzles 5 are provided. The air flow channels of the micro combustion holes 3 penetrate through the body 2. The upstream of the air flow channels of the micro combustion holes 3 is a contraction section, and the downstream is an expansion section. The conveying pipeline 4 is used to supply hydrogen fuel to the micro combustion holes 3. There are a plurality of nozzles 5, and the nozzles 5 correspond to the micro combustion holes 3 one by one. The nozzles 5 are close to the outlets of the corresponding micro combustion holes 3 and connect the conveying pipeline 4 and the micro combustion holes 3. By arranging a plurality of micro combustion holes 3 on the body 2 of the combustion chamber 10 to achieve micro hole lean combustion, the contact area between the fuel and the air can be increased, the emission of NOX can be reduced, and the air flow channels of the micro combustion holes 3 adopt a shape of first contraction and then expansion. Utilizing the fluid flow characteristics, the upstream contraction section is used to accelerate the incoming flow to reduce the risk of flashback, and the downstream expansion section can ensure the outward expansion of the flame surface, leaving enough space for the recirculation zone. That is, the flow channel structure with an upstream contraction section and a downstream expansion section can effectively prevent flashback.

[0044] In this embodiment, the combustion chamber head is annular and is formed by integrating a plurality of fan-shaped bodies 2 as shown in Figure 2 the figure. Of course, in other embodiments, the combustion chamber head can also be integrally formed by a whole ring.

[0045] As Figure 5 shown in the figure, the normal direction of the nozzle 5 is 90° to the flow direction of the air flow in the micro combustion hole 3. Setting the normal direction of the nozzle 5 to be 90° to the flow direction of the air flow in the micro combustion hole 3 enables the hydrogen fuel ejected by the nozzle 5 to enter the micro combustion hole 3 in a lateral injection manner, quickly mix and burn with the air in the air flow channel of the micro combustion hole 3, eliminate local overheating points, reduce the gas temperature, and thus be able to suppress the emission of Nox.

[0046] In this embodiment, the normal direction of the nozzle 5 is set to be 90° to the flow direction of the air flow in the micro combustion hole 3. Of course, in other embodiments, it can also be set adjacent to 90° to achieve that the hydrogen fuel ejected by the nozzle enters the micro combustion hole in a lateral injection manner. For example, the angle formed by the normal direction of the nozzle 5 and the flow direction of the air flow in the micro combustion hole 3 can be between 80° and 90°.

[0047] As Figure 2-4 shown in the figure, a plurality of circles of micro combustion holes 3 are arranged along the circumference of the body 2, and the plurality of circles of micro combustion holes 3 are distributed in multiple layers on the body 2. By arranging multiple circles of combustion holes on the body 2 and setting the multiple circles of micro combustion holes 3 in multiple layers, the flame in the combustion zone can be split into a large number of small flames, increasing the contact area between the fuel and the air.

[0048] As Figure 2-3As shown, there are several delivery pipes 4, and each delivery pipe 4 is arranged between two adjacent layers of micro combustion holes 3, and is used to supply hydrogen fuel to the micro combustion holes 3 on both sides thereof. The micro combustion holes 3 are distributed on both sides of the delivery pipe 4, and hydrogen fuel is supplied to the micro combustion holes 3 on both sides thereof through the delivery pipe 4. The micro combustion holes 3 on both sides share one delivery pipe 4, and the structure is simplified.

[0049] like Figure 2 As shown, the body 2 is also provided with a fuel main pipe 6, and a plurality of delivery pipes 4 are connected to the fuel main pipe 6 in a parallel arrangement, so as to distribute hydrogen fuel to the plurality of delivery pipes 4. The plurality of delivery pipes 4 are arranged in parallel and connected to the fuel main pipe 6 to realize the layered supply of hydrogen fuel, and different equivalence ratios can be allocated on different layers, so as to more flexibly avoid some natural frequencies that cause combustion oscillations. In this embodiment, the parallel arrangement means that a plurality of delivery pipes are connected to the fuel main pipe side by side, and the fuel main pipe supplies hydrogen fuel to the plurality of delivery pipes respectively.

[0050] In this embodiment, a plurality of fuel main pipes 6 are provided and distributed on the fan-shaped main body 2. Of course, in other embodiments, one fuel main pipe 6 may also be provided to transport hydrogen fuel to the multi-layer delivery pipelines through the fuel main pipe 6 to realize layered supply of hydrogen fuel.

[0051] like Figure 2 , Figure 5 As shown, a cooling air slit 7 and a cooling hole 8 are also provided on the main body 2. The cooling hole 8 is connected to the cooling air slit 7. The outlet of the cooling hole 8 is located between two adjacent layers of micro combustion holes 3. The cooling air enters the combustion chamber head 1 through the cooling air slit 7 and flows into the combustion zone through the cooling hole 8.

[0052] By arranging a cooling air slit 7 and a cooling hole 8 on the main body 2, and connecting the cooling hole 8 to the cooling air slit 7, the cooling air enters the combustion chamber head 1 through the cooling air slit 7 and flows into the combustion zone through the cooling hole 8. The cooling air can not only cool the combustion chamber head 1, but also the cooling hole 8 is located between two adjacent layers of micro-combustion holes 3. The cooling air can also separate each small flame, effectively preventing the flames from being connected in series.

[0053] like Figure 2-4 As shown, two adjacent layers of micro combustion holes 3 are arranged in a staggered manner. The staggered arrangement of two adjacent layers of micro combustion holes 3 can reduce or prevent the flame roots of the two adjacent layers of micro combustion holes 3 from being connected in series.

[0054] like Figure 5 As shown, a boss 9 is provided downstream of the airflow of the micro-combustion hole 3. By providing the boss 9 downstream of the airflow of the micro-combustion hole 3, a larger recirculation zone can be formed downstream, and the flame can be better stabilized.

[0055] like Figure 4As shown, the outlet cross-section of the micro combustion holes 3 is arch-shaped, which is conducive to the cooling gas at the cooling head entering through the annular cooling gas slits 7 distributed radially. Preferably, the hydraulic diameter range of the outlet cross-section of the micro combustion holes 3 is 1.5 mm - 3 mm.

[0056] As Figure 1 As shown, the present invention also provides a combustion chamber 10, including a flame tube, which further includes the aforementioned combustion chamber head 1, and the combustion chamber head is located at the end of the flame tube.

[0057] The present invention also provides a gas turbine, which includes the aforementioned combustion chamber 10.

[0058] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only for illustration purposes. The protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A combustion chamber head includes a body, characterized in that, The following are provided on the body: A plurality of micro combustion holes, the air flow channels of the micro combustion holes penetrate through the body, the upstream of the air flow channels of the micro combustion holes is a contraction section, and the downstream is an expansion section; A delivery pipe for supplying hydrogen fuel to the micro combustion holes; A plurality of nozzles, the nozzles corresponding to the micro combustion holes one by one, the nozzles being close to the outlets of the corresponding micro combustion holes and connecting the delivery pipe and the micro combustion holes; the angle formed by the normal direction of the nozzles and the flow direction of the air flow in the micro combustion holes is 80° to 90°.

2. The combustion chamber head according to claim 1, characterized in that, The normal direction of the nozzle forms a 90° angle with the flow direction of the air flow in the micro combustion hole.

3. The combustion chamber head according to claim 1, characterized in that, The micro combustion holes are arranged in multiple circles along the circumference of the body, and the multiple circles of micro combustion holes are distributed in multiple layers on the body.

4. The combustion chamber head according to claim 3, characterized in that, There are several of the delivery pipes, and each delivery pipe is arranged between adjacent two layers of the micro combustion holes for supplying hydrogen fuel to the micro combustion holes on both sides thereof.

5. The combustion chamber head according to claim 4, characterized in that, A fuel manifold is further provided on the body, and the plurality of delivery pipes are connected to the fuel manifold in a parallel connection manner for distributing hydrogen fuel to the several delivery pipes.

6. The combustion chamber head according to claim 3, wherein, A cooling gas slit and cooling holes are further provided on the body, the cooling holes communicate with the cooling gas slit, the outlets of the cooling holes are located between adjacent two layers of the micro combustion holes, and the cooling gas enters the combustion chamber head through the cooling gas slit and flows into the combustion zone through the cooling holes; and / or, the micro combustion holes of adjacent two layers are arranged staggeredly.

7. The combustion chamber head according to claim 1, characterized in that, A boss is provided downstream of the air flow of the micro combustion hole.

8. The combustion chamber head according to claim 6, characterized in that, The outlet section of the micro combustion hole is arch-shaped.

9. A combustion chamber, comprising a flame tube, characterized in that, The combustion chamber further includes a combustion chamber head as described in any one of claims 1-8, and the combustion chamber head is located at the end of the flame tube.

10. A gas turbine, characterized in that, It includes the combustion chamber as described in claim 9.

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