Nozzle of gas inlet system of gas turbine

Abstract

The utility model discloses a nozzle of a gas turbine gas inlet system. When the supercooled water drops in the air flow impact the surface of the nozzle, the original surface curvature and the stable state of the nozzle can be damaged, and finally the supercooled water drops are condensed into ice on the surface of the nozzle. The spray nozzle comprises a spray pipe, an outer shell is arranged on the outer side of the spray pipe, a closed inner cavity is formed between the spray pipe and the outer shell, a plurality of rows of spray pipe spray holes are formed in the cylindrical surface of the lower portion of the spray pipe from top to bottom in a spiral mode, and a plurality of rows of outer shell spray holes are formed in the cylindrical surface of the outer shell from top to bottom in a spiral mode. And the outer layer shell spraying holes are spirally formed in the outer layer shell. The utility model is used for the gas inlet system of the gas turbine.

Description

Technical Field

[0001] The utility model relates to the field of gas turbines, in particular to a nozzle of a gas turbine intake system. Background Art

[0002] Gas turbine generator sets are a kind of power generation equipment widely used in industrial and civil fields at present. Although they have high efficiency, large power and convenient maintenance, they also have problems of noise pollution and icing.

[0003] The main reason for the noise of the gas turbine intake system is that when high-pressure gas passes through the nozzle, due to the increase in flow velocity and the collision of gas molecules, airflow noise will be generated. This kind of noise usually appears as continuous high-frequency sound, has a very wide frequency distribution, is mainly composed of high-frequency components, and its intensity increases rapidly with the increase of the compressor speed, which is a kind of continuous high-frequency noise. The low-frequency noise formed by the thermoacoustic oscillation in the combustion chamber propagates upstream along the intake duct and is finally radiated outward from the intake port, forming low-frequency intake noise with a certain intensity. There are mainly three ways for the intake system noise to spread: the intake passage, the deicing pipeline, and the sound transmission through the wall panel. Among them, the deicing pipeline includes a deicing muffler and a pipeline.

[0004] The reason for the icing of the gas turbine intake system: The influence of the airflow in the intake system on the nozzle surface is also an important factor for icing. When the supercooled water droplets in the airflow hit the nozzle surface, it will destroy its original surface curvature and stable state, and finally cause the supercooled droplets to condense into ice on the nozzle surface. Summary of the Utility Model

[0005] In view of the above deficiencies in the prior art, the utility model provides a nozzle of a gas turbine intake system that uses CFD software to calculate the internal and external flow fields of the nozzle, combines the aerodynamic noise theory to calculate the sound pressure level, conducts research on the calculation method of the nozzle aerodynamic noise, and obtains a nozzle that can reduce noise and prevent icing.

[0006] The purpose of the utility model is achieved through the following technical solutions:

[0007] A nozzle of a gas turbine intake system includes a nozzle tube, an outer shell is arranged outside the nozzle tube, a closed inner cavity is formed between the nozzle tube and the outer shell, a plurality of rows of nozzle holes are arranged on the lower cylindrical surface of the nozzle tube from top to bottom, the nozzle holes are arranged in a spiral shape on the nozzle tube, a plurality of rows of outer shell holes are arranged on the cylindrical surface of the outer shell from top to bottom, and the outer shell holes are arranged in a spiral shape on the outer shell.

[0008] The nozzle holes of two adjacent upper and lower rows are staggered from each other by 120°. The connecting line between the centers of the nozzle holes of two adjacent upper and lower rows and the bottom plane have a nozzle hole stagger angle β, and the range of the nozzle hole stagger angle β is 45° - 75°.

[0009] The diameter of the nozzle orifice is Di, and there is a nozzle orifice spacing Dii between two adjacent upper and lower rows of nozzle orifices. The range of the nozzle orifice spacing Dii is 1.5Di - 1.2Di.

[0010] The outer shell orifices of two adjacent rows are staggered from each other. The connecting line between the centers of the outer shell orifices of two adjacent upper and lower rows and the bottom plane have an outer shell orifice stagger angle α, and the degree of the outer shell orifice stagger angle α is 45°.

[0011] The diameter of the outer shell orifice is Do, and there is an outer shell orifice spacing Doi between two adjacent upper and lower rows of outer shell orifices. The range of the outer shell orifice spacing Doi is 1.5Do - 1.2Do.

[0012] The diameter of the nozzle orifice Di is twice the diameter of the outer shell orifice Do, that is, Di = 1.5 * Do.

[0013] The outer shell diameter Dod is 2 times the nozzle diameter Did, Dod = 2 * Did.

[0014] The number of rows of the outer shell orifices is twice the number of rows of the nozzle orifices.

[0015] The outer shell can be set to three or more according to needs, forming a noise reduction nozzle design for three-stage and multi-stage throttling and pressure reduction.

[0016] Beneficial effects: The present utility model studies the method and effect of reducing the injection noise by adopting two-stage throttling and pressure reduction. By adding an outer cavity outside the orifice, the two sides of the cavity are closed, and orifices with smaller diameters and larger quantities are opened on the wall surface and are distributed in a spiral pattern. Since the flow area of the outer orifices increases, the gas injection is uniform and the speed is reduced, thereby reducing the injection noise. The uniform heating of the small holes and the air flow dispersion effect can further enhance the anti-icing effect. The nozzle with a spiral distribution further improves the efficiency of the nozzle, reduces the noise, and has a better anti-icing effect. Compared with the original structure, through the calculation of CFD software, combining the calculation of the sound pressure level based on the aeroacoustic noise theory, and the research on the calculation method of the nozzle aeroacoustic noise, it is obtained that adopting two-stage throttling and pressure reduction can reduce the injection noise by no less than 4.5 dB(A). According to the same rule, a noise reduction nozzle design for three-stage and multi-stage throttling and pressure reduction can be carried out according to needs. Brief Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of the nozzle of the gas turbine intake system described in the present utility model.

[0018] Figure 2 It is a front view structural schematic diagram of the nozzle of the gas turbine intake system described in the present utility model.

[0019] Figure 3 Schematic cross-sectional view of the nozzle of the gas turbine intake system according to the present utility model. Detailed implementation manners

[0020] The present utility model will be further described in detail below with reference to the drawings and embodiments:

[0021] The middle of the present nozzle has a hollow cylindrical nozzle tube 110. The outer side of the lower part of the nozzle tube 110 is provided with a hollow cylindrical outer shell 130. The lower parts of the nozzle tube 110 and the outer shell 130 are closed by a plate. The upper part of the outer shell 130 and the nozzle tube 110 are closed by a plate. An annular inner cavity 150 is formed between the outer side of the nozzle tube 110 and the inner side of the outer shell 130. A plurality of rows of nozzle holes 120 are provided on the lower cylindrical surface of the nozzle tube 110 from top to bottom. The nozzle holes 120 are arranged in a spiral shape on the nozzle tube 110. Holes with a larger number and smaller diameter are opened on the wall surface of the gas turbine intake nozzle, which have the following effects on noise reduction and anti-icing:

[0022] I. In terms of noise reduction

[0023] 1. Disperse the airflow: Holes with a larger number and smaller diameter can make the airflow more dispersed and uniform, reduce the turbulence and eddy current of the airflow near the nozzle wall surface, and thus reduce the airflow noise.

[0024] 2. Reduce the impact noise: When the airflow passes through the nozzle, impact noise will be generated. By increasing the number of holes and reducing the diameter of the holes, the airflow velocity and impact force of each hole can be reduced, thereby reducing the impact noise.

[0025] 3. Optimize the acoustic design: By accurately calculating and optimizing the arrangement and size of the holes, the noise level can be further reduced. This design can be regarded as an acoustic filter, which can reduce the noise in a specific frequency range.

[0026] II. In terms of anti-icing

[0027] 1. Improve the heat exchange efficiency: Holes with a larger number and smaller diameter can increase the contact area between the nozzle wall surface and the airflow, thereby improving the heat exchange efficiency. In terms of anti-icing, this means that the hot air or heating element can be more effectively used to heat the intake airflow to prevent icing.

[0028] 2. Uniform heating: By evenly distributing the heat through multiple small holes, it can ensure that the intake airflow is uniformly heated on the entire nozzle wall surface, reducing the risk of local icing.

[0029] 3. Enhance the anti-icing effect: Under extreme low temperature conditions, the uniform heating and airflow dispersion effects of the small holes can further enhance the anti-icing effect and ensure the normal operation of the gas turbine intake system.

[0030] In summary, opening more and smaller holes on the wall of the gas turbine inlet nozzle has significant benefits for noise reduction and anti-icing. These measures can not only improve the overall performance and safety of the gas turbine, but also extend its service life. However, in practical applications, precise calculations and optimized designs need to be carried out according to the specific gas turbine model and working conditions to ensure the best results.

[0031] On the cylindrical surface of the outer casing 130, there are multiple rows of outer casing spray holes 140 arranged from top to bottom. The outer casing spray holes 140 are arranged in a spiral shape on the outer casing 130. On the lower cylindrical surface of the nozzle pipe 110, there are multiple rows of nozzle pipe spray holes 120 arranged from top to bottom. The nozzle pipe spray holes 120 in two adjacent upper and lower rows are staggered from each other. The connecting line between the centers of the nozzle pipe spray holes 120 in two adjacent upper and lower rows and the bottom plane have a nozzle pipe spray hole stagger angle β, and the range of the nozzle pipe spray hole stagger angle β is 45° - 75°.

[0032] The diameter of the nozzle pipe spray hole 120 is Di. There is a nozzle pipe spray hole spacing Dii between two adjacent upper and lower rows of nozzle pipe spray holes 120, and the range of the nozzle pipe spray hole spacing Dii is 1.2Di - 1.5Di.

[0033] On the cylindrical surface of the outer casing 130, there are multiple rows of outer casing spray holes 140 arranged from top to bottom. The outer casing spray holes 140 in two adjacent rows are staggered from each other. The connecting line between the centers of the outer casing spray holes 140 in two adjacent upper and lower rows and the bottom plane have an outer casing spray hole stagger angle α, and the degree of the outer casing spray hole stagger angle α is 45°.

[0034] The diameter of the outer casing spray hole 140 is Do. There is an outer casing spray hole spacing Doi between two adjacent upper and lower rows of outer casing spray holes 140, and the range of the outer casing spray hole spacing Doi is 1.2Do - 1.5Do.

[0035] The diameter of the nozzle pipe spray hole Di is twice the diameter of the outer casing spray hole Do, that is, Di = 1.5 * Do.

[0036] The outer casing diameter Dod is 2 times the nozzle pipe diameter Did, Dod = 2 * Did;

[0037] The number of rows of the outer casing spray holes 140 is twice the number of rows of the nozzle pipe spray holes 120;

[0038] Functions of the spiral distribution of the gas turbine inlet nozzle holes on the sleeve:

[0039] 1. Optimize the air flow path: The spiral distribution can make the air flow form a smoother path inside the sleeve, reduce air flow resistance and energy loss, and improve the intake efficiency.

[0040] 2. Improve the mixing uniformity: The spiral distribution helps the fuel and air to mix more fully inside the nozzle, improving the mixing uniformity and thus enhancing the combustion effect.

[0041] 3. Reduce noise: The spiral-distributed air flow can reduce the formation of turbulence and eddy currents, thereby reducing the air flow noise and making the operation of the gas turbine quieter.

[0042] 4. Enhance the anti-icing performance: In a low-temperature environment, the spiral-distributed air flow can better utilize hot air or heating elements to heat the intake air flow, prevent the occurrence of icing, and ensure the normal operation of the gas turbine.

[0043] Multiple layers of outer casings 130 can be set as required to form a noise-reducing nozzle design with three-stage or multi-stage throttling and pressure reduction.

[0044] The advantages of using multiple layers of outer casings for the gas turbine intake nozzle mainly include:

[0045] 1. Optimize the air flow distribution: The multi-layer sleeve design can more effectively control the direction and speed of the air flow, making the air flow more evenly distributed inside the nozzle, thereby improving the combustion efficiency.

[0046] 2. Enhance fuel mixing: The multi-layer sleeve nozzle can better mix the fuel and air, improve the mixing uniformity, contribute to more complete combustion, and reduce pollutant emissions.

[0047] 3. Improve the thermal efficiency: By optimizing the air flow and fuel mixing, the multi-layer sleeve nozzle can improve the thermal efficiency of the gas turbine and reduce fuel consumption.

[0048] 4. Reduce noise: The multi-layer sleeve design can disperse the air flow, reduce the turbulence and eddy currents near the nozzle wall surface, thereby reducing the air flow noise.

[0049] 5. Anti-icing performance: The multi-layer sleeve nozzle can improve the anti-icing performance of the intake system by optimizing the air flow distribution and heating method, and ensure the normal operation of the gas turbine in a low-temperature environment.

Claims

1. A nozzle of a gas turbine intake system, characterized in that : It includes a nozzle (110). An outer shell (130) is provided outside the nozzle (110). A closed inner cavity (150) is formed between the nozzle (110) and the outer shell (130). Multiple rows of nozzle spray holes (120) are provided on the lower cylindrical surface of the nozzle (110) from top to bottom. The nozzle spray holes (120) are arranged in a spiral shape on the nozzle (110). Multiple rows of outer shell spray holes (140) are provided on the cylindrical surface of the outer shell (130) from top to bottom. The outer shell spray holes (140) are arranged in a spiral shape on the outer shell (130).

2. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The upper and lower adjacent rows of the nozzle spray holes (120) are staggered from each other. The connection line between the centers of the upper and lower adjacent rows of the nozzle spray holes (120) and the bottom plane have a nozzle spray hole stagger angle β. The range of the nozzle spray hole stagger angle β is 45°-75°.

3. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The diameter of the nozzle spray hole (120) is Di. There is a nozzle spray hole spacing Dii between the upper and lower adjacent rows of the nozzle spray holes (120). The range of the nozzle spray hole spacing Dii is 1.2Di-1.5Di.

4. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The adjacent two rows of the outer shell spray holes (140) are staggered from each other. The connection line between the centers of the upper and lower adjacent rows of the outer shell spray holes (140) and the bottom plane have an outer shell spray hole stagger angle α. The degree of the outer shell spray hole stagger angle α is 45°.

5. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The diameter of the outer shell spray hole (140) is Do. There is an outer shell spray hole spacing Doi between the upper and lower adjacent rows of the outer shell spray holes (140). The range of the outer shell spray hole spacing Doi is 1.2 Do-1.5Do.

6. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The diameter of the nozzle spray hole Di is twice the diameter of the outer shell spray hole Do, that is, Di = 1.5*Do.

7. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The outer shell diameter Dod is 2 times the nozzle diameter Did, Dod = 2* Did.

8. The nozzle of a gas turbine intake system according to claim 1, characterized in that : The number of rows of the outer shell spray holes (140) is 2 times the number of rows of the nozzle spray holes (120).

9. The nozzle of a gas turbine intake system according to claim 1, characterized in that : Three or more of the outer shells (130) can be provided as needed to form a noise reduction nozzle design for three-stage or multi-stage throttling and pressure reduction.

Images