A mixing hole arrangement for a combustion chamber of a gas turbine

Abstract

The application discloses a mixing hole arrangement structure suitable for a combustion chamber of a gas turbine, and aims at improving combustion efficiency and optimizing airflow distribution, comprising two rows of mixing holes arranged on the front and back of the two side walls of a flame tube base body, the mixing holes sequentially form radial jets with alternating intensity, the high-intensity jet generated by the large-diameter mixing hole ensures radial penetration of the combustion chamber, the low-intensity jet generated by the small-diameter mixing hole compensates for the gap of the circumferential airflow on the opposite side of the former and saves the mixing gas, the front and back mixing holes are staggered to ensure the complement of the mixing gas in the axial direction and prevent the occurrence of insufficient or excessive gas, and the downstream fuel combustion structure is regulated through the mixing gas amount distribution change of the mixing hole spacing and size air bleeding. The mixing hole arrangement structure of the application realizes uniform distribution of the mixing gas while ensuring the penetration of the jet, can be changed and adapted to the engine combustion chamber independently of other components of the engine such as a swirler, an atomizing device and the like, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of gas turbine combustion chamber technology, and relates to a combustion chamber airflow distribution structure, and more particularly to a circumferential and axial arrangement structure of combustion chamber mixing holes. By improving the arrangement structure of the mixing holes, the airflow distribution in the combustion chamber is optimized, thereby improving combustion efficiency and reducing pollutant emissions. Background Technology

[0002] As a key component of modern energy and power systems, the combustion chamber of a gas turbine is where liquid fuel reacts with high-temperature, high-pressure gases. The airflow structure within the combustion chamber determines combustion performance indicators such as stable combustion efficiency, high-temperature zone distribution, and pollutant emissions. In recent years, advanced engines have placed increasingly higher demands on combustion chamber performance, which has spurred the development of more rational air distribution and precise control within the combustion chamber.

[0003] With increasing environmental awareness, the International Civil Aviation Organization (ICAO) is imposing increasingly stringent emission standards on aviation gas turbines, particularly for NOx emissions. For example, the European Aviation Environmental Studies Protocol (ACARE) sets a long-term goal of reducing NOx emissions during the standard landing takeoff (LTO) cycle by 90% by 2050, equivalent to 25% of the existing Civil Aviation Environmental Protection Committee (CAEP / 6) standard. To address this, new low-emission combustor technologies are constantly being developed, including the rich-fuel combustion-quench-lean-fuel combustor (RQL), the dual-annular chamber combustor (DAC), and the dual-annular premixed swirl combustor (TAPS). These technologies aim to meet the future low-emission requirements of large aircraft engines by improving the air-fuel mixing process during combustion.

[0004] Among these technologies, RQL (Reduced Quality) combustion chamber technology has been extensively studied due to its potential in reducing NOx emissions and has already been implemented in some engines. Regarding its LTO (Limited Time Total) emissions, typical RQL technology, when powering small and medium-sized engines, reduces NOx emissions to 55-70% and 55-65% of the CAEP / 6 standard, respectively, demonstrating good pollutant reduction effects. The key to RQL technology lies in creating a rich combustion zone at the head, forming a mixture containing incompletely burned substances, which requires additional oxygen through the mixing orifice for further combustion. Supplemental air is introduced through the combustion chamber wall's supplementary air intake holes to mix with the substances discharged from the rich combustion zone, creating a lean combustion environment before the combustion chamber outlet, thereby effectively suppressing NOx formation. However, conventional mixing orifice arrangements have certain problems. For example, conventional mixing orifice arrangements often only consider introducing mixed air into the combustion chamber, while the circumferential direction often suffers from insufficient mixed air or localized excessive mixed air, resulting in localized high-temperature zones, which are detrimental to reducing NOx formation and also worsen the temperature distribution at the combustion chamber outlet.

[0005] Since the way the mixed gas from the inner and outer channels enters the combustion chamber greatly affects the working state of the combustion chamber, optimizing the arrangement structure of the mixing holes in the combustion chamber to achieve a uniform and reasonable distribution of the mixed gas in the combustion chamber is also an important way to improve the overall combustion performance of the combustion chamber. Therefore, it is also a technical problem that urgently needs to be solved in the development of low emission technology for aero engines. Summary of the Invention

[0006] (I) Purpose of the Invention

[0007] To overcome the shortcomings and deficiencies of the existing combustion chamber mixing hole arrangement in terms of combustion efficiency and airflow distribution uniformity, such as uneven circumferential distribution of mixed gas, excessive or insufficient mixed gas in some areas leading to local high-temperature zones, and poor combustion chamber outlet temperature distribution, this invention aims to provide an improved mixing hole arrangement structure suitable for gas turbine combustion chambers. By setting two rows of mixing holes on both sides of the inner and outer walls of the combustion chamber, and using a staggered arrangement, the mixed gas penetrates the high-temperature combustion gas in the combustion chamber while being evenly distributed circumferentially. The staggered arrangement of the front and rear mixing holes ensures the axial complementarity of the mixed gas and prevents insufficient or excessive gas volume. By changing the distribution of mixed gas volume through the spacing and size of the mixing holes, the downstream fuel combustion structure can be regulated. Through effective airflow control and arrangement optimization, the overall combustion performance of the combustion chamber is significantly improved.

[0008] (II) Technical Solution

[0009] To achieve the objective of this invention and solve its technical problems, the present invention adopts the following technical solution:

[0010] A mixing hole arrangement structure suitable for a gas turbine combustor includes a flame tube base with an integral circumferentially rotating structure. The flame tube base includes an inner wall located radially inward and an outer wall located radially outward. The annular space between the inner and outer walls forms a combustion chamber cavity. A plurality of combustion chamber heads are circumferentially distributed at the upstream end of the combustion chamber cavity. The space within the combustion chamber cavity forms a high-temperature mixed gas passage. The radially outer space of the outer wall forms a first low-temperature mixed gas passage, and the radially inner space of the inner wall forms a second low-temperature mixed gas passage.

[0011] At least two rows of mixing holes are formed along the axial direction on the downstream wall surface of both the inner and outer sides of the flame tube. The number of mixing holes in the front and rear rows is the same on each side wall, and the mixing holes in each row are distributed circumferentially. The front row of mixing holes on the inner side wall has the same axial position as the front row of mixing holes on the outer side wall, and the rear row of mixing holes on the inner side wall has the same axial position as the rear row of mixing holes on the outer side wall.

[0012] Each mixing orifice is a low-temperature mixing gas channel on the flame tube substrate that connects the combustion chamber cavity to the outside, and at least part of its structure extends into the combustion chamber cavity. The portion extending into the combustion chamber cavity is a slanted tubular structure, with the tip of the slanted tubular structure near the downstream side.

[0013] Each row of mixing holes includes large-diameter and small-diameter mixing holes arranged at intervals. Each large-diameter mixing hole is adjacent to two small-diameter mixing holes in the circumferential direction, and each small-diameter mixing hole is adjacent to two large-diameter mixing holes in the circumferential direction.

[0014] Each mixing hole on the inner wall corresponds one-to-one with each mixing hole in the same row on the outer wall and has the same circumferential arrangement. Furthermore, the larger diameter mixing holes on the inner wall are radially aligned with the smaller diameter mixing holes in the same row on the outer wall, and vice versa.

[0015] Each mixing hole in the front row on the same sidewall corresponds one-to-one with each mixing hole in the rear row, and each large-diameter mixing hole in the front row corresponds one-to-one with each small-diameter mixing hole in the rear row and has the same circumferential arrangement position. Each small-diameter mixing hole in the front row corresponds one-to-one with each large-diameter mixing hole in the rear row and has the same circumferential arrangement position.

[0016] Preferably, the mixing orifice is circular or non-circular to improve the guidance and distribution of the mixed gas flow. The size of the mixing orifice is optimized and adjusted according to the required mixing intensity and jet penetration depth to improve combustion efficiency and reduce NOx generation.

[0017] Furthermore, in each row of mixing holes, the mixing holes corresponding to the head of the combustion chamber in the circumferential direction have their diameters increased by 1.2 to 2 times the original diameter. This is to meet the special requirements of the high-temperature area at the head of the combustion chamber for the amount of mixed air, so as to cool the high-temperature area while supplementing air to allow unburned compounds to burn further and improve combustion efficiency.

[0018] Preferably, the centerline of each mixing hole is perpendicular to the tangent of its corresponding side wall surface, and the corresponding mixing holes on the inner and outer side walls are coaxial, so that the airflow direction of each mixing hole is radially toward the combustion chamber cavity.

[0019] Preferably, the obliquely cut tubular structure of each mixing hole extending into the combustion chamber is used to guide the direction of the mixed gas jet. The length of the jet extending into the combustion chamber is positively correlated with its aperture size, so as to improve the penetration depth and mixing efficiency of the large-aperture mixing jet and ensure that the small-aperture mixing jet effectively supplements and covers the large-aperture mixing jet in the circumferential direction.

[0020] Preferably, the obliquely cut tubular structure of each mixing hole extending into the combustion chamber cavity has a rounded corner structure at the junction of its root outer surface and the inner wall of the base. The machining accuracy and dimensions of the rounded corner structure are optimized according to the specific working conditions of the combustion chamber to ensure the durability and mixing effect of the mixing hole.

[0021] Preferably, the obliquely cut tubular structure of each mixing hole extending into the combustion chamber cavity has an oblique cutting angle of 20° to 60° and is tilted towards the downstream direction of the combustion chamber, so that the mixed gas jet can be more effectively mixed with the high-temperature mixed gas in the combustion chamber cavity. The specific oblique cutting angle is selected based on the need to optimize the mixing effect and control the jet direction, so as to achieve a balance between jet penetration and mixing efficiency.

[0022] Preferably, the total gas flow through all mixing holes is controlled according to the design and operating conditions of the combustion chamber, and it should be ensured that the mixing jet generated by the large-diameter mixing holes can penetrate the entire combustion chamber to form a dominant mixing effect and combustion support.

[0023] Furthermore, while keeping the total gas volume flowing through all mixing holes constant, the number and diameter of each row of mixing holes are adjusted according to the combustion requirements of different locations in the combustion chamber, so that the large-diameter mixing jet has a larger gas volume and radial velocity, and the small-diameter mixing jet fills the gap without being excessive.

[0024] Preferably, the axial spacing between the front and rear rows of mixing holes is adjusted according to the fuel quantity and the axial velocity of the head mixture to ensure that the unburned compounds generated in the front row of mixing holes are fully burned when flowing through the rear row of mixing holes, so as to avoid the emission of unburned compounds.

[0025] (III) Technical Effects

[0026] The mixing hole arrangement structure of the present invention, applicable to the combustion chamber of a gas turbine, has significant technical advantages compared with the prior art:

[0027] (1) This invention optimizes the design of the mixing hole arrangement structure to rationally distribute the air in the combustion chamber, thereby increasing the mixing jet depth under the same air volume conditions. By increasing the penetration depth of the mixing jet, it achieves full mixing with the high-temperature mixed air, thereby improving combustion efficiency and reducing pollutant generation.

[0028] (2) This invention achieves uniform mixing across the entire circumferential cross-section of the combustion chamber by creating complementary mixtures between gases at different depths. This design optimizes the airflow distribution within the combustion chamber, ensuring that each region receives an appropriate amount of mixed gas, thus avoiding local over- or under-mixing. Uniform mixing not only helps improve combustion efficiency but also improves the temperature distribution at the combustion chamber outlet, thereby enhancing the overall performance and reliability of the engine.

[0029] (3) This invention provides additional cooling to the high-temperature zone at the head of the combustion chamber, improving the outlet temperature distribution performance. This is achieved by increasing the orifice diameter at the mixing orifice corresponding to the high-temperature zone. Larger mixing orifices can provide more mixed gas in these critical areas, helping to quickly reduce local high temperatures and thus more effectively control the temperature distribution of the entire combustion chamber. This effective temperature control not only improves combustion efficiency but also helps reduce the formation of harmful substances such as nitrogen oxides caused by excessively high temperatures. Attached Figure Description

[0030] Figure 1 This is an isometric view of the mixing hole arrangement structure of the present invention applicable to the combustion chamber of a gas turbine;

[0031] Figure 2 This is an axial cross-sectional view of the front and rear rows of holes under the mixing hole arrangement method of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Inner wall of the flame tube, 2. Outer wall of the flame tube, 3. Mixing hole, 4. Second low-temperature mixed gas channel, 5. First low-temperature mixed gas channel, 6. Inner cavity of the combustion chamber. Detailed Implementation

[0034] To better understand the present invention, the following embodiments further illustrate its content. Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, of the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The structure and technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings, providing one embodiment of the present invention.

[0035] To overcome the shortcomings and deficiencies of existing combustion chamber mixing hole arrangement methods in terms of combustion efficiency and airflow distribution uniformity, such as uneven distribution of mixed gas in the circumferential direction, excessive or insufficient mixed gas in some areas leading to the generation of local high-temperature zones, and poor combustion chamber outlet temperature distribution, this invention provides a mixing hole arrangement structure suitable for gas turbine combustion chambers.

[0036] As a specific example, such as Figure 1 , 2As shown, the mixing hole arrangement structure of the present invention, applicable to the combustion chamber of a gas turbine, adopts a pattern of alternating large and small mixing holes in the circumferential and front-to-back direction. It includes a flame tube base that rotates circumferentially as a whole. The flame tube base includes an inner wall 1 located radially inward and an outer wall 2 located radially outward. The annular space between the inner wall 1 and the outer wall 2 forms the combustion chamber cavity 6. A plurality of combustion chamber heads are circumferentially distributed at the upstream end of the combustion chamber cavity 6. The space of the combustion chamber cavity 6 forms a high-temperature mixed gas passage. The radially outer space of the outer wall 2 forms a first low-temperature mixed gas passage 5, and the radially inner space of the inner wall 1 forms a second low-temperature mixed gas passage 4. The entire base is located at the midpoint of the combustion chamber's axial direction.

[0037] At least two rows of mixing holes are formed axially on the downstream walls of both the inner wall 1 and the outer wall 2 of the flame tube. The number of mixing holes in the front and rear rows is the same on each side wall, and each mixing hole 3 in each row is distributed circumferentially. The front row of mixing holes on the inner wall has the same axial position as the front row of mixing holes on the outer wall, and the rear row of mixing holes on the inner wall has the same axial position as the rear row of mixing holes on the outer wall. Each mixing hole is a jet air channel on the flame tube base that connects the combustion chamber cavity to the outside of the flame tube, with at least a portion of its structure extending into the combustion chamber cavity. The portion extending into the combustion chamber cavity is a slanted tubular structure, with the tip of the slanted tubular structure near the downstream side. Each row of mixing holes includes large-diameter mixing holes and small-diameter mixing holes arranged at intervals. Large-diameter mixing holes are adjacent to two small-diameter mixing holes in the circumferential direction, and each small-diameter mixing hole is adjacent to two large-diameter mixing holes in the circumferential direction. Each mixing hole on the inner sidewall corresponds one-to-one with each mixing hole in the same row on the outer sidewall and has the same circumferential arrangement position. The large-diameter mixing holes on the inner sidewall are all radially aligned with each small-diameter mixing hole in the same row on the outer sidewall, and the small-diameter mixing holes on the inner sidewall are all radially aligned with the large-diameter mixing holes on the outer sidewall. Each mixing hole in the front row on the same sidewall corresponds one-to-one with each mixing hole in the back row, and the large-diameter mixing holes in the front row correspond one-to-one with each small-diameter mixing hole in the back row and have the same circumferential arrangement position. Each small-diameter mixing hole in the front row corresponds one-to-one with each large-diameter mixing hole in the back row and has the same circumferential arrangement position.

[0038] The mixing hole arrangement structure of this invention, applicable to gas turbine combustors, operates on the following principle: Based on the complementary nature of the mixed gas in both the circumferential and circumferential directions to rationally distribute the gas volume, a mixing jet formed by large-diameter mixing holes radially penetrates the combustor. Small-diameter mixing holes adjacent to and opposite the circumferential direction supplement the undermixed zone with mixed gas, ensuring the complementary mixing gas flow of large and small holes achieves uniform distribution across the axial cross-section. The front row of mixing holes quenches the rich combustion mixture at the head and acts as air supplement to create a lean combustion environment. The rear row of mixing holes cuts off the central high-temperature zone and ensures complete combustion of the combustible portion. Furthermore, the staggered arrangement of mixing holes forms radial jets with alternating intensity and volume. High-intensity jets penetrate the combustor radially to achieve mixing and quenching effects, while low-intensity jets complement the mixed gas in adjacent and opposite directions, ensuring the mixed gas covers the entire combustor plane, resulting in complete combustion and a more uniform temperature distribution. The staggered size of the front and rear mixing holes allows for axial superposition and supplementation of mixed gas while avoiding local over-mixing. The increased diameter of the mixing holes at the head of the combustion chamber increases the amount of mixed gas, which promotes the combustion reaction and reduces the temperature in the high-temperature zone. The distribution of the mixed gas volume through the mixing holes controls the combustion performance of the downstream fuel.

[0039] In some preferred embodiments, the axes of the mixing holes 3 on the inner and outer walls are perpendicular to the tangential direction of the inner and outer walls. The incoming flow channels in the inner second low-temperature mixed gas channel 4 and the outer first low-temperature mixed gas channel 5 are formed by the negative pressure of the combustion chamber cavity 6 in the radial direction to form a mixing jet, which mixes with the high-temperature mixed gas with high axial velocity in the inner cavity to complete the mixing.

[0040] In the mixing hole arrangement structure of the present invention applicable to the combustion chamber of a gas turbine, a large-diameter mixing hole on one side wall of the flame tube substrate is directly opposite a small-diameter mixing hole. That is, the axis of the single row of holes is located in the same axial plane, and the axis of the inner and outer mixing holes is the same, with the same circumferential spacing angle. The mixing region formed by the large-diameter mixing gas flow is difficult to cover the opposite side. Therefore, the opposite side is complemented by a small-diameter mixing hole, which avoids excessive overlap between the mixing effect and the large-diameter mixing hole. In addition, the small gas volume of the small-diameter mixing hole allows most of the mixing gas to be concentrated in the large-diameter mixing hole to form a mixing jet with high penetration depth.

[0041] In the mixing hole arrangement structure applicable to the combustion chamber of a gas turbine of the present invention, the size of the single row of mixing holes 3 on the flame tube substrate is staggered in the circumferential direction. The circumferential gap of the mixing zone formed by the large-diameter mixing holes is filled by a small hole between the two large-diameter mixing holes, which makes up for the circumferential gap between the large holes and avoids waste caused by excessive mixing gas.

[0042] In the mixing hole arrangement structure applicable to the combustion chamber of a gas turbine of the present invention, the large-diameter mixing holes in the front row of the flame tube substrate correspond to the small-diameter mixing holes in the rear row, reducing the accumulation of mixed gas in the axial direction and thus reducing excess. Since the mixing holes in the front row are arranged in a staggered manner in the circumferential direction, the large-diameter mixing holes in the rear row cooperate with the small-diameter mixing holes in the front row to compensate for the insufficient mixed gas in the axial direction.

[0043] In some preferred embodiments, the diameters of the mixing holes on the flame tube substrate corresponding to the central cross-section of the combustion chamber head are increased, which has an additional cooling effect on the high-temperature zone formed by combustion. In addition, the supplementation of air can further burn unburned compounds to improve combustion efficiency.

[0044] The combustion chamber mixing hole arrangement of the present invention, based on the clamping fit of the large and small holes in the circumferential and axial directions, allows more gas to be concentrated in the large hole to form a mixed jet with a high penetration depth in the combustion chamber, and achieves uniform distribution of mixed gas in the circumferential direction under relatively smaller mixed gas volume conditions, avoiding gas waste caused by overlapping mixing areas, improving the overall combustion efficiency of the combustion chamber and optimizing the outlet temperature distribution.

[0045] In some preferred embodiments, the shape and size of the mixing orifice can be optimized according to the flow characteristics inside the combustion chamber. In addition to traditional circular mixing orifices, different shapes, such as elliptical, rectangular, or other non-circular orifices, can be designed to improve the guidance and distribution of the mixed gas flow. Simultaneously, the size of the mixing orifice can be designed according to the required mixing intensity and jet penetration depth to improve combustion efficiency and reduce NOx formation.

[0046] In some preferred embodiments, the obliquely cut tubular structure of each mixing orifice extending into the combustion chamber has a rounded corner at the junction of its root outer surface and the inner wall of the base. The machining precision and dimensions of the rounded corner are optimized according to the specific operating conditions of the combustion chamber to ensure the durability and mixing effect of the mixing orifice. Furthermore, the obliquely cut angle of each mixing orifice extending into the combustion chamber is 20°–60°, tilted towards the downstream direction of the combustion chamber. This allows the mixed gas jet to mix more effectively with the high-temperature mixture in the combustion chamber. The specific oblique angle is selected based on the need to optimize the mixing effect and control the jet direction to achieve a balance between jet penetration and mixing efficiency.

[0047] In some preferred embodiments, the total gas flow through all mixing orifices is controlled according to the design and operating conditions of the combustion chamber, ensuring that the mixing jet generated by the large-diameter mixing orifices can penetrate the entire combustion chamber to form a dominant mixing effect and combustion support. Simultaneously, while maintaining a constant total gas flow through all mixing orifices, the number and diameter of each row of mixing orifices are adjusted according to the combustion requirements of different locations within the combustion chamber, ensuring that the large-diameter mixing jet has a large gas flow and radial velocity, while the small-diameter mixing jet fills gaps without becoming excessive.

[0048] In practical applications of this invention, the aperture size of a single mixing hole, the circumferential spacing of a single row of holes, and the axial spacing of the front and rear rows of mixing holes can be varied. Overall, the mixing jet formed by a single large hole can penetrate the combustion chamber radially. The small holes adjacent to each other and on opposite sides supplement the undermixed zone with mixed gas, so that the mixed gas flow of the large and small holes complements each other to be evenly distributed in the axial cross section. The front row of mixing holes quenches the oil-rich combustion mixture at the head and serves as air supplement to form an oil-lean combustion environment. The mixed gas from the rear row of mixing holes cuts off the central high-temperature zone and ensures complete combustion of the combustible part.

[0049] In summary, this invention achieves a rational distribution and complementarity of the mixed gas in the circumferential and axial directions by setting an alternating arrangement of mixing holes of different sizes on the flame tube base of the combustion chamber. It fully utilizes the high impulse and penetration capability of the large-diameter jet, as well as the supplementary coverage effect of the small-diameter jet, thereby solving problems such as uneven mixing and localized temperature anomalies in existing technologies. This results in uniform and efficient mixing of the high-temperature mixture throughout the combustion chamber. Furthermore, by optimizing the number, diameter, and total volume of mixing holes in each row, combined with the combustion characteristics at different axial positions, customized fine mixing control can be achieved. This maximizes combustion efficiency, reduces pollutant emissions, and optimizes the outlet temperature distribution, thereby comprehensively improving the overall combustion performance and operating economy of the gas turbine, and has broad application prospects.

[0050] The objectives of this invention have been fully and effectively achieved through the above embodiments. Those skilled in the art will understand that this invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments described above. Although the invention has been described with reference to what is currently considered the most practical and preferred embodiments, it should be understood that the invention is not limited to the disclosed embodiments, and any modifications that do not depart from the functional and structural principles of the invention will be included within the scope of the claims.

Claims

1. A mixing hole arrangement structure suitable for a gas turbine combustion chamber, comprising a flame tube base with an integral circumferential rotating structure, the flame tube base including an inner sidewall of the flame tube located radially inward and an outer sidewall of the flame tube located radially outward, the annular space between the inner sidewall and the outer sidewall of the flame tube forming an inner cavity of the combustion chamber, a plurality of combustion chamber heads being circumferentially distributed at the upstream end of the inner cavity of the combustion chamber, the space of the inner cavity of the combustion chamber forming a high-temperature mixed gas channel, the radially outer space of the outer sidewall of the flame tube forming a first low-temperature mixed gas channel, and the radially inner space of the inner sidewall of the flame tube forming a second low-temperature mixed gas channel, characterized in that, At least two rows of mixing holes are formed along the axial direction on the downstream wall surface of both the inner and outer sides of the flame tube. The number of mixing holes in the front and rear rows is the same on each side wall, and the mixing holes in each row are distributed circumferentially. The front row of mixing holes on the inner side wall of the flame tube has the same axial position as the front row of mixing holes on the outer side wall of the flame tube, and the rear row of mixing holes on the inner side wall of the flame tube has the same axial position as the rear row of mixing holes on the outer side wall of the flame tube. Each mixing orifice is a low-temperature mixing gas channel on the flame tube substrate that connects the combustion chamber cavity to the outside, and at least part of its structure extends into the combustion chamber cavity. The portion extending into the combustion chamber cavity is a slanted tubular structure, with the tip of the slanted tubular structure near the downstream side. Each row of mixing holes includes large-diameter and small-diameter mixing holes arranged at intervals. Each large-diameter mixing hole is adjacent to two small-diameter mixing holes in the circumferential direction, and each small-diameter mixing hole is adjacent to two large-diameter mixing holes in the circumferential direction. Each mixing hole on the inner wall of the flame tube corresponds one-to-one with each mixing hole in the same row on the outer wall of the flame tube and has the same circumferential arrangement. Furthermore, the larger diameter mixing holes on the inner wall of the flame tube are radially aligned with the smaller diameter mixing holes in the same row on the outer wall of the flame tube, and vice versa. Each mixing hole in the front row on the same sidewall corresponds one-to-one with each mixing hole in the rear row, and each large-diameter mixing hole in the front row corresponds one-to-one with each small-diameter mixing hole in the rear row and has the same circumferential arrangement position. Each small-diameter mixing hole in the front row corresponds one-to-one with each large-diameter mixing hole in the rear row and has the same circumferential arrangement position.

2. The mixing hole arrangement structure suitable for gas turbine combustion chambers according to claim 1, characterized in that, The centerline of each mixing hole is perpendicular to the tangent of its corresponding side wall surface. The corresponding mixing holes on the inner and outer side walls are coaxial, so that the airflow direction of each mixing hole is radially toward the combustion chamber cavity.

3. The mixing hole arrangement structure suitable for gas turbine combustion chambers according to claim 1, characterized in that, The obliquely cut tubular structure of each mixing orifice extending into the combustion chamber is used to guide the direction of the mixed gas jet. The length of the jet extending into the combustion chamber is positively correlated with the size of the orifice, so as to improve the penetration depth and mixing efficiency of the large-diameter mixing jet, and ensure that the small-diameter mixing jet effectively supplements and covers the large-diameter mixing jet in the circumferential direction.

4. The mixing hole arrangement structure suitable for gas turbine combustion chambers according to claim 1, characterized in that, Each mixing hole has a beveled tubular structure extending into the combustion chamber cavity. The outer surface of its root is machined with a rounded corner structure at the junction with the inner wall of the flame tube base. The machining accuracy and dimensions of the rounded corner structure are optimized according to the specific working conditions of the combustion chamber to ensure the durability and mixing effect of the mixing hole.

5. The mixing hole arrangement structure suitable for gas turbine combustion chambers according to claim 1, characterized in that, The total gas flow through all mixing holes should be controlled according to the design and operating conditions of the combustion chamber, and it should be ensured that the mixing jet generated by the large-diameter mixing holes can penetrate the entire combustion chamber to form a dominant mixing effect and combustion support.

6. The mixing hole arrangement structure suitable for a gas turbine combustion chamber according to claim 5, characterized in that, While keeping the total gas volume flowing through all mixing holes constant, the number and diameter of each row of mixing holes are adjusted according to the combustion requirements of different locations in the combustion chamber, so that the large-diameter mixing jet has a large gas volume and radial velocity, and the small-diameter mixing jet fills the gap without being excessive.

7. The mixing hole arrangement structure suitable for gas turbine combustion chambers according to claim 1, characterized in that, The axial spacing between the front and rear rows of mixing holes is adjusted according to the fuel quantity and the axial velocity of the head mixture to ensure that unburned compounds generated in the front row of mixing holes are fully burned when flowing through the rear row of mixing holes, thereby avoiding the emission of unburned compounds.

8. The mixing hole arrangement structure suitable for gas turbine combustion chambers according to claim 1, characterized in that, The mixing orifice can be circular or non-circular to improve the guidance and distribution of the mixed gas flow. The size of the mixing orifice is optimized according to the required mixing intensity and jet penetration depth to improve combustion efficiency and reduce NOx formation.

9. The mixing hole arrangement structure suitable for a gas turbine combustion chamber according to claim 8, characterized in that, In each row of mixing holes, the mixing holes corresponding to the head of the combustion chamber in the circumferential direction have an additionally enlarged diameter, which is 1.2 to 2 times the original diameter, in order to meet the special requirements of the high-temperature area of ​​the combustion chamber head for the amount of mixed air. This allows for cooling of the high-temperature area while supplementing air to further burn unburned compounds and improve combustion efficiency.

10. The mixing hole arrangement structure suitable for a gas turbine combustion chamber according to claim 1, characterized in that, Each mixing hole has a beveled tubular structure extending into the combustion chamber cavity. The bevel angle is 20° to 60° and it is tilted towards the downstream direction of the combustion chamber. This allows the mixed gas jet to mix more effectively with the high-temperature mixture in the combustion chamber cavity. The specific bevel angle is selected based on the need to optimize the mixing effect and control the jet direction in order to achieve a balance between jet penetration and mixing efficiency.

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