A gas turbine with improved combustion stability

Abstract

The application discloses a gas turbine capable of improving combustion stability, which comprises a combustion and compression cylinder, the combustion and compression cylinder comprises an outer shell, an inner shell, a plurality of support columns, a plurality of metal wires and a plurality of connecting pipes, the support columns are arranged between the outer shell and the inner shell, one end of the metal wires is connected with the support columns, and the other end of the metal wires extends away from the support columns, a plurality of main sound-absorbing holes are formed in the inner shell, two ends of the connecting pipes are connected with the outer shell and the inner shell respectively, the connecting pipes are in one-to-one position correspondence with the main sound-absorbing holes and are communicated with each other, and a plurality of secondary sound-absorbing holes are formed in the side wall of the connecting pipes, so that the combustion and compression cylinder has the function of absorbing the noise generated by the exhaust of the compressor, the exhaust pressure pulsation of the compressor can be reduced, the air flowing out of the combustion and compression cylinder can continuously and stably enter the combustion chamber, and the combustion stability of the gas turbine is improved.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and more specifically to a gas turbine that can improve combustion stability. Background Technology

[0002] Gas turbines are highly efficient and reliable energy conversion devices widely used in power generation, aviation, and industrial fields. Compared to traditional steam power systems, gas turbines offer many significant advantages. For example, they have rapid start-up and shutdown capabilities, meaning they can reach rated power output quickly to meet emergency power demands or respond to rapid changes in market demand. Furthermore, compared to traditional fuel power systems such as coal or heavy oil, gas turbines offer lower emissions and are more environmentally friendly. Specifically, they typically burn cleaner fuels, such as natural gas or liquefied petroleum gas, resulting in fewer pollutant emissions. Additionally, gas turbines can employ advanced combustion technologies and emission control devices during combustion, significantly reducing emissions of harmful substances such as nitrogen oxides and particulate matter.

[0003] Although heavy-duty gas turbines are already widely used in the power generation industry, they commonly employ lean-burn premixed low-NOx combustion technology to reduce emissions of pollutants such as nitrogen oxides. However, lean-burn premixed low-NOx combustion is highly sensitive to changes in the incoming air and fuel flow, making it prone to thermoacoustic coupling oscillations that lead to combustion instability. For example, when there are large pressure pulsations in the compressor exhaust, these pulsations are transmitted to the flame tube through the fuel nozzles, interfering with the combustion process and causing combustion instability. Furthermore, pressure pulsations in the compressor exhaust, once they enter the combustion chamber, also affect the air and fuel flow rates entering the combustion chamber. This results in more fuel being injected at low pressures and less at high pressures. This instability in fuel injection supply can significantly induce thermoacoustic coupling oscillations, leading to combustion instability.

[0004] In view of the above shortcomings, it is necessary to design a gas turbine that can improve combustion stability. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the exhaust pressure of the compressor in existing gas turbines is pulsating, which leads to unstable combustion, thereby providing a gas turbine that can improve combustion stability.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A gas turbine with improved combustion stability includes a combined combustion and compressor cylinder. The combined combustion and compressor cylinder includes an outer shell, an inner shell, multiple support columns, multiple metal wires, and multiple connecting pipes. The support columns are positioned between the outer shell and the inner shell. One end of each metal wire is connected to a support column, and the other end extends away from the support column. The inner shell has multiple main silencing holes. The two ends of each connecting pipe are connected to the outer shell and the inner shell, respectively. The connecting pipes correspond to and communicate with the main silencing holes. The sidewalls of the connecting pipes have multiple secondary silencing holes, enabling the combined combustion and compressor cylinder to silence the noise generated by the compressor exhaust.

[0008] Furthermore, the diameter of the main silencing hole is larger than the diameter of the secondary silencing hole.

[0009] Furthermore, the diameter of the main silencing hole is 10mm to 25mm, and / or the diameter of the secondary silencing hole is 2mm to 5mm.

[0010] Furthermore, the diameter of the metal wire is on the order of millimeters.

[0011] Furthermore, multiple metal wires are arranged radially and evenly on the support column along its circumference.

[0012] Furthermore, one end of the connecting pipe abuts against the outer casing, and the other end of the connecting pipe is inserted into the main silencing hole.

[0013] Furthermore, the plurality of support columns are divided into a plurality of parallel support column groups, and the plurality of connecting pipes are divided into a plurality of parallel connecting pipe groups, with a support column group provided on each side of each connecting pipe group.

[0014] Furthermore, each of the connecting pipes is surrounded by four adjacent supporting columns.

[0015] Furthermore, the combustion and pressure cylinder is made of spring steel.

[0016] Furthermore, the gas turbine is a heavy-duty gas turbine, which also includes a compressor. The high-pressure air discharged from the compressor is suitable for entering the combined combustion and pressure cylinder, and the noise generated by the exhaust is suitable for being silenced by the combined combustion and pressure cylinder.

[0017] The technical solution of this invention has the following advantages:

[0018] 1. This invention provides a gas turbine with improved combustion stability, comprising a combined combustion and pressure cylinder. The combined combustion and pressure cylinder includes an outer shell, an inner shell, multiple support columns, multiple metal wires, and multiple connecting pipes. The support columns are positioned between the outer shell and the inner shell. One end of each metal wire is connected to a support column, and the other end extends away from the support column. Multiple main silencing holes are provided on the inner shell. The two ends of the connecting pipes are respectively connected to the outer shell and the inner shell. The connecting pipes correspond to and communicate with the main silencing holes. Secondary silencing holes are provided on the sidewalls of the connecting pipes. In this way, noise entering the combined combustion and pressure cylinder is diverted from the main silencing holes. The noise enters the connecting pipe through a silencing hole. Under the action of the viscous force of the air in the connecting pipe, the noise is first attenuated. The attenuated noise then enters the interlayer space between the inner and outer shells through a secondary silencing hole on the connecting pipe. Under the action of the viscous force of the air in the interlayer space, it is attenuated again, and then reaches the metal wire. Under the action of the noise sound pressure, the metal wire vibrates and deforms, converting the noise energy into vibration mechanical energy. This can significantly reduce the noise of the air in the combined combustion and compression cylinder, reduce the pressure pulsation of the air in the combined combustion and compression cylinder, and ultimately stabilize the airflow entering the combustion chamber, thereby improving the combustion stability of the gas turbine.

[0019] 2. The present invention provides a gas turbine that can improve combustion stability. The main silencer hole has a diameter of 10mm to 25mm. Compared with the traditional micro-perforated plate silencer structure, which requires minimizing the diameter of the silencer hole to increase the acoustic impedance of the silencer structure and broaden the silencer frequency band, the main silencer hole in this embodiment is larger in size. On the one hand, it can reduce the processing difficulty, and on the other hand, it is beneficial for noise to enter the interior of the connecting pipe through the main silencer hole, so as to silence more noise, thereby helping to further reduce the pressure pulsation of the air in the combustion and compression cylinder and further improve the combustion stability of the gas turbine.

[0020] 3. The present invention provides a gas turbine that can improve combustion stability. The diameter of the metal wire is on the order of millimeters. In this way, the metal wire can be deformed more easily to convert noise energy into vibrational mechanical energy, thereby significantly reducing the pressure pulsation of air in the combustion chamber and further improving the combustion stability of the gas turbine.

[0021] 4. The present invention provides a gas turbine that can improve combustion stability, wherein multiple metal wires are arranged radially and evenly on the support column in a dense manner along the circumference of the support column, so that noise from each silencer hole can be silenced as much as possible.

[0022] 5. The present invention provides a gas turbine that can improve combustion stability. The combustion and pressure cylinder is made of spring steel to better adapt to high temperature and high pressure environment and avoid affecting the noise reduction effect of the combustion and pressure cylinder.

[0023] 6. The present invention provides a gas turbine that can improve combustion stability. Multiple support columns are divided into multiple parallel support column groups, and multiple connecting pipes are divided into multiple parallel connecting pipe groups. Each connecting pipe group has a support column group on both sides. Each connecting pipe is surrounded by four adjacent support columns. In this way, the noise entering from each main silencer hole can be consumed by the surrounding structure, further improving the silencer effect, and ultimately further reducing the pressure pulsation of the air in the combustion and compression cylinder and further improving the combustion stability of the gas turbine. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the internal structure of the heavy-duty gas turbine that improves combustion stability in this invention;

[0026] Figure 2 This is a three-dimensional structural diagram of the sound-absorbing structure in this invention;

[0027] Figure 3 This is a side view of the sound-absorbing structure in this invention;

[0028] Figure 4 This is a first cross-sectional schematic diagram of the sound-absorbing structure in this invention;

[0029] Figure 5 This is a second cross-sectional schematic diagram of the sound-absorbing structure in this invention;

[0030] Figure 6 This is a schematic diagram of the metal wires arranged on the support column in this invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Intake channel; 2. Compressor; 3. Combustion chamber; 4. Turbine; 5. Combustion and compression cylinder; 6. Exhaust section; 61. Exhaust section guide plate; 7. Shaft; 71. Thrust bearing; 72. Turbine bearing; 8. Front cylinder of combustion chamber; 9. Rear cylinder of combustion chamber; 11. Standby fuel pipe; 12. Main fuel pipe; 13. Burner; 14. Fuel nozzle cap; 15. Igniter; 16. Flame tube; 17. Transition section; 171. Air vent; 172. Jacketed flow channel; 18. Fuel nozzle purge pipe; 61. Exhaust section guide plate; 21. Inner shell; 22. Outer shell; 23. Support column; 24. Metal wire; 25. Main silencer hole; 26. Secondary silencer hole; 27. Connecting pipe. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of 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.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Example

[0038] like Figures 1 to 6 As shown, this embodiment provides a gas turbine that can improve combustion stability. Specifically, the gas turbine is a heavy-duty gas turbine. Although a gas turbine has many components, this invention mainly describes the components related to this invention and their connection relationships, as follows:

[0039] The intake duct 1 is funnel-shaped, providing an entry channel for air. The compressor 2 is located within the intake duct 1. The rotor diameter of the compressor 2 gradually decreases in the air entry direction; therefore, the compressor 2's flow channel is a contracting flow channel with a gradually decreasing flow area. The air, pressurized by the compressor 2, enters the combustion chamber / combustion cylinder 5. The combustion chamber / combustion cylinder 5 has the function of silencing the noise generated during the air discharge process of the compressor 2, thereby reducing the pressure pulsation of the airflow within the combustion chamber / combustion cylinder 5 and improving the stability of the airflow entering the combustion chamber 3. The combustion chamber 3 is obliquely inserted into the combustion chamber / combustion cylinder 5. A turbine 4 is installed inside the turbine casing. The exhaust section 6 is connected to the cavity inside the turbine casing. The exhaust section 6 is designed with four circumferentially evenly arranged exhaust section guide plates 61 to enhance the structural strength of the exhaust section 6. A rotating shaft 7 is mounted at the center of the gas turbine, rotating around its own axis. The compressor 2 and turbine 4 are both mounted on the rotating shaft 7. At the compressor end, the rotating shaft 7 is supported by a thrust bearing 71, and at the turbine end, it is supported by a turbine bearing 72. The burner 13 is mounted on a fuel nozzle cover 14, which is connected to the side wall of the combustion chamber front cylinder 8. The combustion chamber front cylinder 8 is connected to the combustion chamber rear cylinder 9, which is mounted on the combustion and compression cylinder 5. A flame tube 16 is connected to the fuel nozzle cover 14, and an igniter 15 is mounted on the flame tube 16. A transition section 17 is connected to the flame tube 16 and is obliquely inserted into the combustion and compression cylinder 5. The outlet of the transition section 17 is connected to the inlet of the turbine 4. A shift fuel pipe 11, a main fuel pipe 12, and a fuel nozzle cleaning pipe 18 are mounted on the fuel nozzle cover 14 and are all connected to the burner 13.

[0040] In this embodiment, the combined combustion and pressure cylinder 5 is made of spring steel to adapt to high temperature and high pressure environments. The combined combustion and pressure cylinder 5 includes an inner shell 21, an outer shell 22, multiple support columns 23, multiple metal wires 24, and multiple connecting pipes 27.

[0041] The support column 23 is a solid cylinder, evenly distributed between the outer shell 22 and the inner shell 21. The support column 23 serves two purposes: firstly, it enhances the structural strength of the combustion chamber cylinder 5; secondly, it houses the metal wires 24. The metal wires 24 have a diameter in the millimeter range, allowing them to deform more easily and convert noise energy into vibrational mechanical energy. This significantly reduces air pressure pulsation within the combustion chamber cylinder 5, ensuring a continuous and stable flow of air from the cylinder into the combustion chamber 3, thereby improving the combustion stability of the gas turbine. Multiple metal wires 24 are arranged radially and densely along the circumference of the support column 23, maximizing the attenuation of noise from the various silencer holes 26.

[0042] Multiple main silencer holes 25 are evenly distributed on the inner shell 21. The diameter of the main silencer holes 25 is 10mm to 25mm. Compared with the traditional micro-perforated plate silencer structure, which requires minimizing the diameter of the silencer holes to increase the acoustic impedance and broaden the silencer frequency band, the main silencer holes 25 in this embodiment have a larger diameter of 10mm to 25mm. This reduces the processing difficulty of the main silencer holes 25 and facilitates the entry of noise into the connecting pipe 27 through the main silencer holes 25, thereby silencing more noise and further reducing the pressure pulsation of air in the combustion and compression cylinder 5, and further improving the combustion stability of the gas turbine. The spacing between two adjacent main silencer holes 25 is 3mm to 5mm.

[0043] The two ends of the connecting pipe 27 are connected to the outer shell 22 and the inner shell 21, respectively. The connecting pipe 27 corresponds to and communicates with the main silencing holes 25. Multiple secondary silencing holes 26 are provided on the side wall of each connecting pipe 27. Specifically, one end of the connecting pipe 27 abuts against the outer shell 22, and the other end is inserted into the main silencing hole 25. The diameter of the secondary silencing holes 26 is smaller than that of the main silencing holes 25; specifically, the diameter of the secondary silencing holes 26 is 2mm to 5mm, and the distance between adjacent silencing holes 26 is 1mm to 2mm.

[0044] In this embodiment, the multiple support columns 23 are divided into multiple parallel support column groups, and the multiple connecting pipes 27 are divided into multiple parallel connecting pipe groups. Each connecting pipe group has a support column group on both sides, and each connecting pipe 27 is surrounded by four adjacent support columns 23. In this way, the noise entering from each main silencer hole 25 can be consumed by the surrounding environment, further improving the silencer effect, and ultimately further reducing the pressure pulsation of the air in the combustion and compression cylinder 5 and further improving the combustion stability of the gas turbine.

[0045] The following describes the working process of a gas turbine that can improve combustion stability, as provided in this embodiment:

[0046] Outside air is drawn into the gas turbine by the high-speed rotating compressor 2 through the intake duct 1. After being compressed and pressurized in stages by the compressor 2, it is discharged into the combustion chamber 5. Because the combustion chamber 5 is a large annular cavity, it has a buffering effect on the high-pressure air discharged from the compressor. In addition, the combustion chamber 5 can convert the pressure pulsation energy of the high-pressure air into the mechanical vibration energy of the silencer structure, thereby reducing the pressure pulsation of the high-pressure air in the combustion chamber 5. After being buffered and the pressure pulsation is reduced, the high-pressure air enters the interlayer flow channel 172 formed by the outer and inner walls of the transition section 17 through the air hole 171 on the outer wall of the transition section 17. Then, it flows counterclockwise along the interlayer flow channel 172 to the head of the flame tube 16 and enters the burner 13 through the air inlet on the head wall of the flame tube 16. At the same time, the main fuel and the standby fuel enter the burner 13 through the main fuel pipe 12 and the standby fuel pipe 11, respectively. In the burner 13, the main air and the main fuel participating in combustion are mixed. After the fuel is evenly mixed, it is injected into the flame tube 16 in a rotating jet manner, forming a recirculation zone downstream of the burner 13. The recirculation zone is filled with the high-temperature gas after combustion, which ignites the fresh combustible mixture injected into the flame tube 16 and stabilizes the combustion flame. After the air and fuel are fully combusted in the flame tube 16 to form high-temperature gas, they are further mixed evenly in the transition section 17, making the gas temperature distribution at the outlet of the transition section 17 more uniform and reducing the thermal stress impact on the turbine blades caused by uneven gas temperature distribution. The high-temperature, high-pressure gas ejected from the outlet of the transition section 17 expands and does work in the turbine 4 in stages, driving the shaft 7 to rotate at high speed. The shaft 7 can drive the generator to rotate and continuously output electrical energy. The exhaust gas after doing work is discharged from the gas turbine through the exhaust section 6. In order to improve the utilization of exhaust gas waste heat, a waste heat boiler is generally arranged downstream of the gas turbine to further utilize the heat of the exhaust gas and improve energy utilization efficiency.

[0047] In this embodiment, the noise reduction process of the combustion and pressure cylinder 5 is as follows:

[0048] When the gas turbine is working, noise is generated during the discharge of high-pressure air from the compressor 2. The noise enters the connecting pipe 27 through the main silencer 25 and is first attenuated by the viscosity of the air in the connecting pipe 27. The attenuated noise then enters the interlayer space between the inner shell 21 and the outer shell 22 through the secondary silencer 26 on the connecting pipe 27. It is attenuated again by the viscosity of the air in the interlayer space and then reaches the metal wire 24. Under the action of the noise sound pressure, the metal wire 24 vibrates and deforms, converting the noise energy into vibration mechanical energy. This can significantly reduce the noise of the air in the combustion chamber 5 and ultimately reduce the pressure pulsation of the air in the combustion chamber 5, so that the air flowing out of the combustion chamber 5 can enter the combustion chamber 3 continuously and stably, thereby improving the combustion stability of the gas turbine. In this embodiment, the high-pressure air noise energy entering the combustion and pressure cylinder 5 is converted into mechanical energy through the mechanical vibration deformation of the metal wire 24, which has the advantage of energy absorption and conversion across the entire noise frequency range. In contrast, the traditional honeycomb silencing structure, which utilizes the Helmholtz resonant cavity principle, can only absorb and dissipate the noise frequency energy that resonates with the gas in the resonant cavity, and the noise at other frequencies cannot be absorbed well. Therefore, the combustion and pressure cylinder 5 in this embodiment has the advantage of a wide noise absorption frequency range.

[0049] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A gas turbine that can improve combustion stability, characterized in that, The gas turbine includes a combined combustion and pressure cylinder (5), which includes an outer shell (22), an inner shell (21), multiple support columns (23), multiple metal wires (24), and multiple connecting pipes (27). The support columns (23) are supported between the outer shell (22) and the inner shell (21). One end of the metal wire (24) is connected to the support column (23), and the other end extends away from the support column (23). Multiple main silencer holes (25) are provided on the inner shell (21). The two ends of the connecting pipe (27) are respectively connected to the outer shell (22) and the inner shell (21). The connecting pipe (27) and the main silencer holes (25) are in corresponding positions and connected to each other. Multiple secondary silencer holes (26) are provided on the side wall of the connecting pipe (27).

2. A gas turbine with improved combustion stability according to claim 1, characterized in that, The diameter of the main silencing hole (25) is larger than the diameter of the secondary silencing hole (26).

3. A gas turbine with improved combustion stability according to claim 2, characterized in that, The diameter of the main silencing hole (25) is 10 mm to 25 mm, and / or the diameter of the secondary silencing hole (26) is 2 mm to 5 mm.

4. A gas turbine with improved combustion stability according to claim 1, characterized in that, The diameter of the metal wire (24) is on the order of millimeters.

5. A gas turbine with improved combustion stability according to claim 1, characterized in that, Multiple metal wires (24) are arranged radially and evenly on the support column (23) along the circumference of the support column (23).

6. A gas turbine with improved combustion stability according to claim 1, characterized in that, One end of the connecting pipe (27) abuts against the outer shell (22), and the other end of the connecting pipe (27) is inserted into the main silencing hole (25).

7. A gas turbine with improved combustion stability according to claim 1, characterized in that, The multiple support columns (23) are divided into multiple support column groups that are parallel to each other, and the multiple connecting pipes (27) are divided into multiple connecting pipe groups that are parallel to each other. Each connecting pipe group has a support column group on both sides.

8. A gas turbine with improved combustion stability according to claim 7, characterized in that, Each of the connecting pipes (27) is surrounded by four adjacent support columns (23).

9. A gas turbine with improved combustion stability according to any one of claims 1-8, characterized in that, The combustion and pressure cylinder (5) is made of spring steel.

10. A gas turbine with improved combustion stability according to any one of claims 1-8, characterized in that, The gas turbine is a heavy-duty gas turbine, which also includes a compressor (2). The high-pressure air discharged by the compressor (2) is suitable to enter the combined combustion and pressure cylinder (5), and the noise generated by the exhaust is suitable to be silenced by the combined combustion and pressure cylinder (5).

Images