A gas turbine multi-nozzle array staged combustor head

Abstract

This invention provides a multi-nozzle array staged combustor head for gas turbines, comprising a shift nozzle, a primary main combustion nozzle, a secondary main combustion nozzle, a combustion chamber end cooling plate, a shift fuel distribution chamber, a primary main combustion fuel distribution chamber, and a secondary main combustion fuel distribution chamber. It employs a staged, zoned nozzle arrangement, with the load increasing progressively from the inside out. By controlling the area of ​​the film cooling holes and the area of ​​the lateral air inlets on the combustion chamber end cooling plate, the velocity of the cooling film cooling holes is ensured to be lower than the nozzle velocity, and the inclined opening of the cooling film cooling holes does not affect the combustion flame. Each stage of the fuel pipe has an independent fuel distribution chamber for gas distribution, ensuring uniform gas distribution and flexible fuel adjustment. This invention can achieve the effects of reducing pollutant emissions, suppressing thermoacoustic instability, and widening the range of heat load adjustment.

Description

Technical Field

[0001] This invention belongs to the field of gas turbines, and specifically relates to a multi-nozzle array staged burner head for gas turbines. Background Technology

[0002] The design of gas turbine combustors is rapidly evolving towards higher efficiency, lower emissions, and greater stability, driving advancements in many combustion technologies. Micro-mixing combustion, multi-nozzle arrays, and gentle combustion are novel combustion technologies proposed in recent years. The design philosophy of these methods primarily involves reducing the mixing scale of air and fuel, thereby improving the uniformity of the premixed gas. Compared to lean premixed combustion and swirl premixed combustion, this combustion organization method can reduce NOx and improve the backfire resistance of hydrogen-rich fuels. However, the reduced nozzle size leads to higher nozzle exit velocities, thus posing requirements for combustion stability at high speeds. Currently, however, the nozzle arrangement in multi-nozzle array combustors has limitations in ensuring combustor heat load and combustion stability, failing to meet the requirements for suppressing thermoacoustic oscillations and controlling pollutant emissions. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a multi-nozzle array staged burner head for gas turbines, designed to meet the needs of gas turbine load regulation, pollutant emission control, and suppression of thermoacoustic instability. It employs a fuel-staged, zoned nozzle arrangement, with the load gradually increasing from the inside out. First, a high equivalence ratio and stable recirculation zone are formed in the central duty area to ensure flame stability. The primary and secondary main combustion stages are used to increase load and control NOx emissions. The primary and secondary main combustion nozzles are radially divided into four stages, with the nozzle diameter gradually increasing from the inside to the outside to meet the thermal intensity requirements of the gas turbine. The axial relative position, diameter, and number of fuel orifices of the duty nozzle and main combustion nozzle work together to suppress thermoacoustic instability. After the combustion chamber is radially layered, the outermost nozzle has a lower equivalence ratio, and the flame is in an elevated state. Due to the different equivalence ratios between layers, the flue gas can be remixed, further reducing NOx emissions. By controlling the area of ​​the film cooling holes and the area of ​​the lateral air inlets on the cooling plate at the end of the combustion chamber, the velocity of the cooling film cooling holes is kept lower than the nozzle velocity, and the inclined opening of the cooling film cooling holes does not affect the combustion flame. Each stage of the fuel pipe has an independent fuel distribution chamber for gas distribution, ensuring the uniformity of gas distribution and the flexibility of fuel adjustment.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A multi-nozzle array staged burner head for a gas turbine includes a standby fuel inlet, a primary main combustion fuel inlet, a secondary main combustion fuel inlet, a cooling gas lateral inlet on the combustion chamber end plate, fuel nozzles, and a fuel chamber baffle. The fuel chamber baffle divides the burner's fuel chamber into a primary main combustion fuel distribution chamber, a secondary main combustion fuel distribution chamber, and a standby fuel distribution chamber. The standby fuel, primary fuel, and secondary fuel can be independently controlled, supplying gas to the central standby zone, the primary main combustion zone, and the secondary main combustion zone, respectively. The standby fuel enters the standby fuel distribution chamber through the standby fuel inlet. The primary fuel enters the distribution ring chamber through the primary main combustion fuel inlet and then enters the primary main combustion fuel distribution chamber through a mixing hole on the wall. The secondary fuel enters the secondary main combustion fuel distribution chamber through the secondary main combustion fuel inlet. The fuel entering the primary and secondary main combustion fuel distribution chambers then enters the fuel nozzle through a nozzle fuel mixing hole on the nozzle pipe, where it mixes with the air entering from the air inlet.

[0006] Preferably, the fuel nozzle consists of a central n×n array nozzle and m layers of annular array nozzles, where 3≤n≤5 and 3≤m≤8;

[0007] The average velocity of the nozzle tube is 30m / s to 150m / s;

[0008] The diameter of the nozzle tube increases in a stepped manner from the inner layer to the outer layer, and the diameter D1 of the nozzle ranges from 4mm to 10mm.

[0009] Preferably, the central duty zone is composed of duty nozzles with an inner diameter of Dp arranged in an n×n array, wherein the range of Dp is 4mm≤Dp≤10mm, the central duty zone forms a high equivalence ratio, the duty equivalence ratio ranges from 0.7 to 0.8, and the central recirculation zone ensures the stable characteristics of the combustion chamber flame.

[0010] Preferably, the nozzles in the primary combustion zone are used for continuous flame and consist of two symmetrical fan-shaped nozzles, the angle of which is determined according to the continuous flame range of the annular combustion chamber.

[0011] The nozzles in the secondary main combustion zone are used to adjust the overall burner load and suppress thermal and acoustic instability.

[0012] Preferably, the axial relative position, diameter, and number of the fuel mixing holes in the nozzle work together to resist the influence of pressure fluctuations;

[0013] The diameter D2 of the nozzle fuel mixing orifice ranges from 0.5 mm to 2.0 mm, and the velocity range of the nozzle fuel mixing orifice is the same, ranging from 100 m / s to 300 m / s. The high-velocity fuel orifice is used to counteract the influence of combustion chamber pressure pulsation on fuel supply.

[0014] The axial relative position and opening direction of the nozzle fuel mixing hole and its adjacent fuel hole are different, which is used to avoid the superposition and coupling of combustion chamber pressure fluctuations, resulting in nozzle thermoacoustic oscillation coupling.

[0015] Preferably, the burner has a circumferentially oriented cooling gas side inlet hole on the combustion chamber end plate, and the total area of ​​the cooling gas side inlet hole on the combustion chamber end plate is Aci, accounting for 5%-10% of the total air intake area at the head.

[0016] Preferably, the combustion chamber end plate cooling plate has cooling film holes, the total area of ​​the cooling film holes is Acf, and 3Aci≥Acf≥1.5Aci, so as to control the speed of the cooling film holes to be no greater than the nozzle exit speed.

[0017] Preferably, the cooling film holes are angled openings in the central duty area, which cool the nozzle tube outlet without affecting the flame structure.

[0018] Preferably, the opening angle of the cooling film hole is within 30° to 50°, and the diameter D3 of the cooling film hole is in the range of 0.5 mm to 2.0 mm.

[0019] Preferably, the number of fuel holes in the nozzles of the primary combustion zone and the secondary combustion zone is k, where 2≤k≤6, and the diameter of the fuel holes in the outermost nozzles of the primary combustion zone and the secondary combustion zone is smaller than the diameter of the inner fuel holes, thereby achieving a low equivalence ratio in the outermost layer and causing the outer flame to rise, which is beneficial for controlling the generation of pollutants by mixing flue gas.

[0020] As can be seen from the above technical solution, the gas turbine multi-nozzle array burner head of the present invention has at least one or a part of the following beneficial effects:

[0021] (1) The burner head adopts an array-level arrangement, and each nozzle is supplied with gas separately by a corresponding gas distribution chamber. The gas distribution chamber is optimized to meet the requirements of uniform gas distribution. The heat load of each area of ​​the head can be independently controlled to achieve the uniformity of the burner temperature field and reduce pollutant emissions.

[0022] (2) The opening positions of the fuel holes on any two adjacent nozzles are different along the axial and radial directions, so that the distance between the fuel and the flame zone is different, thereby modulating the phase difference between the fuel and the heat release. This can avoid the superposition and coupling of combustion chamber pressure fluctuations, and the occurrence of nozzle thermoacoustic oscillation coupling.

[0023] (3) The outermost fuel hole diameter is smaller than the inner fuel hole diameter, which can produce a lower outermost equivalent. The outer flame is in an elevated state, which is conducive to the mixing of flue gas and the control of pollutant generation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a multi-nozzle array staged burner head for a gas turbine according to an embodiment of the present invention;

[0025] Figure 2a , Figure 2b This is a first perspective view of the air distribution chamber driven by the present invention; wherein, Figure 2a Main view, Figure 2b This is a cross-sectional view;

[0026] Figure 3 This is a first cross-sectional view of the gas distribution chamber of the present invention;

[0027] Figure 4 This is a second cross-sectional view of the gas distribution cavity of the present invention;

[0028] Figure 5 This is a schematic diagram of the fuel nozzle of the present invention;

[0029] Figure 6 This is a schematic diagram of the overall flame structure of a multi-nozzle array staged burner head for a gas turbine according to the present invention.

[0030] Among them, 100-gas turbine multi-nozzle array staged burner head; 101-standby fuel inlet; 102-primary main combustion fuel inlet; 103-secondary main combustion fuel inlet; 104-combustion chamber end plate cooling gas side inlet; 105-fuel nozzle; 106-fuel chamber baffle; 107-combustion chamber end plate cooling plate; 108-cooling gas film hole; 109-nozzle fuel mixing hole; 110-air inlet; 111-secondary main combustion fuel distribution chamber distribution hole; S1-primary main combustion fuel distribution chamber; S2-secondary main combustion fuel distribution chamber; P-standby fuel distribution chamber; C-cooling gas chamber; H-distribution ring chamber. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be noted beforehand that the directional terms mentioned in the embodiments of this invention, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this invention.

[0032] like Figures 1-4 As shown, the gas turbine multi-nozzle array staged burner head 100 provided in this embodiment of the invention includes three fuel inlets, namely a standby fuel inlet 101, a primary main combustion fuel inlet 102, and a secondary main combustion fuel inlet 103, and also includes a combustion chamber end plate cooling gas side air inlet 104, a fuel nozzle 105, and a fuel chamber baffle 106.

[0033] Micro-hybrid combustion technology requires the uniform distribution of air and fuel to each burner nozzle. In this embodiment, the fuel chamber is divided into a standby fuel distribution chamber P (i.e., the standby zone), a primary main combustion fuel distribution chamber S1 (i.e., the primary main combustion zone), and a secondary main combustion fuel distribution chamber S2 (i.e., the secondary main combustion zone). Standby fuel enters the standby fuel distribution chamber P through the standby fuel inlet 101. Primary fuel enters the primary main combustion fuel distribution chamber S1 through the primary main combustion fuel inlet 102, and secondary fuel enters the distribution ring chamber H through the secondary main combustion fuel inlet 103. The distribution ring chamber H is a cavity formed by the inner wall of the burner head and the outer wall of the distribution chamber. Since the secondary main combustion fuel inlet 103 and the secondary main combustion fuel distribution chamber S2 are not directly connected, the secondary fuel needs to enter the secondary main combustion fuel distribution chamber S2 through the secondary main combustion fuel distribution port 111 opened on the distribution ring chamber H. The fuel that enters the primary fuel distribution chamber S1 and the secondary fuel distribution chamber S2 then enters the fuel nozzle 105 through the fuel mixing hole 109 on the nozzle tube of the fuel nozzle 105, and mixes with the air that enters from the air inlet 110.

[0034] The number of fuel holes in the outermost layer of the primary combustion zone nozzle and the secondary combustion zone nozzle is less than the number of fuel holes in the inner layer, which can achieve a low equivalence ratio in the outermost layer and make the outer flame appear to rise, which is conducive to the mixing of flue gas and control of pollutant generation.

[0035] In one specific embodiment, the fuel nozzle 105 is vertically mounted on the burner, and the sealing with each gas distribution chamber can be achieved by additive manufacturing technology or brazing process. The diameter of the nozzle tube of the fuel nozzle 105 is determined by the average nozzle exit velocity. In this embodiment, the average nozzle exit velocity is set to 60 m / s, and the corresponding diameter of the fuel nozzle 105 is between 5.6 mm and 7 mm. The fuel nozzle 105 has nozzle fuel mixing holes 109 in the circumferential and axial directions, such as... Figure 5 As shown, the diameter of the nozzle fuel mixing orifice 109 is different in each region, and the area of ​​the nozzle fuel mixing orifice 109 is allocated according to the equivalence ratio of each region. In this embodiment, the diameter of the nozzle fuel mixing orifice 109 is between 0.6mm and 0.8mm, and the circumferential and axial positions of the nozzle fuel mixing orifice 109 on adjacent nozzle tubes are different, which can avoid the superposition and coupling of combustion chamber pressure fluctuations, and the occurrence of nozzle thermoacoustic oscillation coupling.

[0036] In one specific embodiment, the burner is equipped with a combustion chamber end plate cooling plate 107 for cooling the part that is in direct contact with the flame. The combustion chamber end plate cooling plate 107 has cooling gas film holes 108. Cooling gas enters the cooling gas chamber C through the combustion chamber end plate cooling gas side inlet 104 and is discharged through the cooling gas film holes 108 to cool the cooling plate.

[0037] In this embodiment, the total area Aci of the side air inlets 104 of the combustion chamber end plate cooling gas is controlled so that the velocity entering the cooling gas chamber C is about 20 m / s. The total area Acf of the cooling film holes 108 is twice the total area Aci of the side air inlets 104 of the combustion chamber end plate cooling gas, and the velocity of the cooling gas discharged from the cooling film holes 108 is less than 10 m / s. Since a stable recirculation zone needs to be formed in the duty zone to stabilize the flame, in order to reduce the influence of cooling air on the flow field, the cooling film holes 108 in the duty zone are 45° oblique openings, and the remaining areas are vertical openings.

[0038] like Figure 6 The diagram illustrates the flame stabilization method and flame pattern of the multi-nozzle array staged burner head 100 for a gas turbine according to an embodiment of the present invention. Due to the large center-to-center spacing of the central control nozzles, a small recirculation zone is formed at the center of adjacent fuel nozzles 105, thereby achieving a flame stabilization effect. Since the equivalence ratio of the outermost fuel nozzles 105 in the main combustion stage is smaller than that of the inner nozzles, unburned reactants are not ignited at the nozzle outlet. They are ignited after being mixed with the high-temperature flue gas, resulting in a raised flame effect. However, due to the higher equivalence ratio of the inner nozzles and the effect of the central recirculation zone, the unburned reactants are ignited at the nozzle outlet.

[0039] It should also be noted that the present invention can provide examples of parameters containing specific values, but these parameters need not be exactly equal to the corresponding values, but can be approximated to the corresponding values ​​within acceptable error tolerances or design constraints; the above embodiments can be used in combination with each other or with other embodiments based on design and reliability considerations, that is, the technical features of different embodiments can be freely combined to form more embodiments.

[0040] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-nozzle array staged burner head for a gas turbine, characterized in that, It includes a standby fuel inlet, a primary main combustion fuel inlet, a secondary main combustion fuel inlet, a cooling gas side inlet on the combustion chamber end plate, fuel nozzles, and a fuel chamber baffle. The fuel chamber baffle divides the burner's fuel chamber into a primary main combustion fuel distribution chamber, a secondary main combustion fuel distribution chamber, and a standby fuel distribution chamber. The standby fuel, primary fuel, and secondary fuel can be independently controlled to supply gas to the central standby zone, the primary main combustion zone, and the secondary main combustion zone, respectively. The standby fuel enters the standby fuel distribution chamber through the standby fuel inlet. The primary fuel enters the primary main combustion fuel distribution chamber through the primary main combustion fuel inlet, and the secondary fuel enters the distribution ring cavity through the secondary main combustion fuel inlet. The distribution ring cavity is a cavity formed by the inner wall of the burner head and the outer wall of the distribution cavity. The secondary fuel enters the secondary main combustion fuel distribution chamber through the secondary main combustion fuel distribution hole opened on the distribution ring cavity. The fuel that enters the primary and secondary main combustion fuel distribution chambers then enters the fuel nozzle through the fuel mixing hole on the nozzle pipe, where it is mixed with the air entering from the air inlet.

2. The gas turbine multi-nozzle array staged burner head according to claim 1, characterized in that: The fuel nozzle consists of a central n×n array nozzle and m layers of annular array nozzles, where 3≤n≤5 and 3≤m≤8; The average velocity of the nozzle tube is 30m / s to 150m / s; The diameter of the nozzle tube increases in a stepped manner from the inner layer to the outer layer, and the diameter D1 of the nozzle ranges from 4mm to 10mm.

3. The gas turbine multi-nozzle array staged burner head according to claim 1, characterized in that: The central duty zone consists of duty nozzles with an inner diameter of Dp arranged in an n×n array, where Dp ranges from 4mm to 10mm. The central duty zone forms a high equivalence ratio, with a duty equivalence ratio range of 0.7-0.

8. At the same time, the central recirculation zone ensures the stable characteristics of the combustion chamber flame.

4. The gas turbine multi-nozzle array staged burner head according to claim 1, characterized in that: The nozzles in the primary combustion zone are used for flame continuity and consist of two symmetrical fan-shaped nozzles. The angle of the fan-shaped nozzles is determined according to the flame continuity range of the annular combustion chamber. The nozzles in the secondary main combustion zone are used to adjust the overall burner load and suppress thermal and acoustic instability.

5. The gas turbine multi-nozzle array staged burner head according to claim 1, characterized in that: The axial relative position, diameter, and number of nozzle fuel mixing holes work together to resist the influence of pressure fluctuations. The orifice diameter D2 of the nozzle fuel mixing orifice ranges from 0.5 mm to 2.0 mm, and the velocity range of the nozzle fuel mixing orifice is the same, ranging from 100 m / s to 300 m / s. The high-velocity nozzle fuel mixing orifice is used to counteract the influence of combustion chamber pressure pulsation on fuel supply. The axial relative position and opening direction of the fuel mixing orifice of the nozzle are different from those of its adjacent fuel mixing orifices. This is to avoid the superposition and coupling of combustion chamber pressure fluctuations, which could lead to nozzle thermoacoustic oscillation coupling.

6. The gas turbine multi-nozzle array staged burner head according to claim 1, characterized in that: The burner has circumferentially opened combustion chamber end plate cooling gas side air inlet holes, the total area of ​​the combustion chamber end plate cooling gas side air inlet holes is Aci, accounting for 5%-10% of the total head air intake area.

7. The gas turbine multi-nozzle array staged burner head according to claim 6, characterized in that: The combustion chamber end plate cooling plate has cooling film holes with a total area of ​​Acf, and 3Aci≥Acf≥1.5Aci, so as to control the speed of the cooling film holes to be no greater than the nozzle exit speed.

8. The gas turbine multi-nozzle array staged burner head according to claim 7, characterized in that: The cooling film holes are angled openings in the central duty area, which cool the nozzle tube outlet without affecting the flame structure.

9. The gas turbine multi-nozzle array staged burner head according to claim 7, characterized in that: The opening angle of the cooling film orifice is within 30° to 50°, and the diameter D3 of the cooling film orifice ranges from 0.5 mm to 2.0 mm.

10. The gas turbine multi-nozzle array staged burner head according to claim 7, characterized in that: The number of fuel mixing holes in the nozzles of the primary combustion zone and the secondary combustion zone is k, where 2≤k≤6. The diameter of the fuel mixing holes in the outermost nozzles of the primary combustion zone and the secondary combustion zone is smaller than that in the inner nozzles, thereby achieving a low equivalence ratio in the outermost layer and causing the outer flame to rise, which is beneficial for controlling the generation of pollutants by mixing the flue gas.

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