Dual-fuel air premixing nozzle and gas turbine

Abstract

The present invention discloses a dual-fuel air premixing nozzle and gas turbine, comprising: a nozzle body, a first fuel pipe, a second fuel pipe, and an air inlet provided on the nozzle body, and a mounting plate provided within the nozzle body to partition the internal space of the nozzle body; a first inlet hole and a second inlet hole are provided on the mounting plate to communicate with the internal space of the nozzle body partitioned by the mounting plate; the first inlet hole and the second inlet hole are arranged orthogonally. Through the above arrangement, the fuels ejected through the first inlet hole and the second inlet hole can intersect with each other, achieving a premixing effect, while maintaining the consistency of the flow field and uniformity of the two fuels downstream, achieving a better mixing effect between the fuel and the air, and making it easier to control the equivalence ratio distribution of the two fuels; in addition, the high-flow fuel will also guide the low-flow fuel, increasing the jet velocity of the low-flow fuel and reducing the possibility of backfire.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas turbines, and in particular relates to a dual-fuel air premixing nozzle and a gas turbine. Background Art

[0002] Gas turbines have the advantages of high efficiency, small size, light weight, simple maintenance, good maneuverability, high degree of automation and low cost. Therefore, they are widely used in aviation, land-based power generation, natural gas transportation, petroleum, railway and shipbuilding industries.

[0003] In traditional gas turbines, due to the rich variety of modern energy sources, including natural gas, hydrogen, ammonia, and even a large amount of industrial by-products, oil field associated gas, and biomass energy, the nozzles in traditional gas turbine combustion chambers cannot adapt to the simultaneous transmission of multiple fuels, resulting in serious energy waste.

[0004] At the same time, renewable energy sources such as photovoltaics and wind power are on the rise, and hydrogen- and ammonia-blended fuels are used for energy storage and peak regulation. However, traditional nozzles are not widely applicable and cannot be applied to different fuel types, different types of gas turbines or different application scenarios.

[0005] It is difficult to control the combustion of multi-fuel energy, and it is difficult to mix hydrogen and ammonia, which can easily reduce the stability of fuel combustion in the combustion chamber, thereby reducing ignition reliability. The internal flow field structure of traditional nozzles cannot adapt to this. Summary of the Invention

[0006] The present invention aims to solve at least one of the problems in the above-mentioned background technology and provide a dual-fuel air premixing nozzle and a gas turbine.

[0007] To achieve the above objectives, the present invention provides a dual fuel air premixing nozzle, comprising:

[0008] The nozzle body includes a first fuel pipe, a second fuel pipe, a first fuel channel, a second fuel channel, an air inlet hole, and a mounting plate provided on the nozzle body. The mounting plate is provided inside the nozzle body and separates a fuel chamber and a mixing chamber inside the nozzle body. The air inlet hole is provided on the outer wall of the mixing chamber.

[0009] The mounting plate is provided with a first inlet hole communicating with the mixing chamber and the first fuel channel, and a second inlet hole communicating with the mixing chamber and the second fuel channel;

[0010] The first incident hole is arranged orthogonally to the second incident hole. The first incident hole is located between the air inlet hole and the first fuel channel, and the second incident hole is located between the air inlet hole and the second fuel channel.

[0011] Preferably, the air inlet hole includes a first air inlet hole and a second air inlet hole;

[0012] The first air inlet hole is arranged close to the mounting plate, and an opening area of ​​the first air inlet hole is larger than an opening area of ​​the second air inlet hole;

[0013] The openings of the first air inlet hole and the second air inlet hole are configured as radially oblique openings, and the oblique directions of the first air inlet hole and the second air inlet hole are opposite to each other.

[0014] Preferably, the bevel angle of the radial bevel opening is in the range of 20°-40°.

[0015] Preferably, the first air inlet hole and the second air inlet hole are configured as key-shaped holes.

[0016] Preferably, the first fuel channel coincides with the central axis of the nozzle body, and the second fuel channel wraps around the first fuel channel;

[0017] A first inlet hole is radially arranged on the first fuel channel, and a second inlet hole is axially arranged on the second fuel channel.

[0018] Preferably, the second incident hole is arranged close to the outer wall of the nozzle body.

[0019] Preferably, the first air inlet holes and the second air inlet holes are evenly arranged along the circumference of the side wall of the nozzle body.

[0020] Preferably, the number of the first air inlet holes and the number of the second air inlet holes are the same.

[0021] Preferably, a mounting flange is provided on the side wall of the nozzle body.

[0022] To achieve the above objectives, the present invention further provides a gas turbine comprising a dual-fuel air premixing nozzle as described in any one of the above.

[0023] Based on this, the beneficial effects of the present invention are:

[0024] 1. According to the solution of the present invention, a mounting plate is provided within the nozzle body, which divides the internal space of the nozzle body. A first inlet hole and a second inlet hole are provided on the mounting plate. The first inlet hole and the second inlet hole are arranged in an alternating manner, so that the ejected airflows intersect with each other. This allows for better pre-mixing of the two fuel jets, maintains consistency in the flow field and uniformity of the two fuels downstream, achieves better mixing, and also makes it easier to control the equivalence ratio distribution of the two fuels.

[0025] At the same time, since there are main fuel and auxiliary fuel in the dual fuel, the flow rate of the auxiliary fuel is relatively small. After the main fuel is ejected through the injection hole, it can guide the auxiliary fuel, increase the injection speed of the auxiliary fuel, and reduce the possibility of flashback.

[0026] 2. Through the solution of the present invention, a first fuel channel and a second fuel channel are further provided in the nozzle body. The first fuel channel is connected to the first fuel pipe, and the second fuel channel is connected to the second fuel pipe. After the fuel enters the channel, it can be stabilized in the channel first. When the fuel is ejected through the injection port, it can have a good initial uniformity, thereby improving the mixing effect, making the combustion more stable and avoiding the problem of flashback.

[0027] 3. Through the solution of the present invention, the second injection hole is arranged close to the air inlet hole, so that the fuel can be mixed with the air entering from the air inlet hole immediately after being ejected, thereby improving the mixing effect of the fuel and air;

[0028] 4. Through the solution of the present invention, the first inlet hole is placed close to the air inlet hole while the second inlet hole is placed close to the air inlet hole. This creates a large gap between the two fuel outlets, ensuring better mixing with the air from the second air inlet hole. If the gap between the two inlet holes is too small, the overall mixing effect will be affected.

[0029] 5. The present invention provides two air inlet holes, further improving the mixing effect. Furthermore, the second air inlet hole is configured as an oblique opening, which allows the air entering the nozzle body to form a swirl flow, "stirring" the fuel and further improving the mixing effect.

[0030] 6. Through the solution of the present invention, the first air inlet hole is also set as a radial beveled opening, and the bevel directions of the two are set in opposite directions. On the one hand, the shear force of the airflow can be used to further enhance the mixing of fuel and air. On the other hand, through the two-stage swirl, the airflow can be returned to the axial direction, ensuring the circumferential mixing effect while making the airflow jet along the axial direction, thereby improving the flow field performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A perspective view schematically showing a dual fuel air premixing nozzle according to one embodiment of the present invention;

[0032] Figure 2 A top view schematically illustrating a dual fuel air premixing nozzle according to one embodiment of the present invention;

[0033] Figure 3 Schematically shows an embodiment of the present invention Figure 2 Cross-sectional view along the A-A' direction;

[0034] Description of the drawings: nozzle body 10, fuel chamber 101, first fuel channel 1011, second fuel channel 1012, mixing chamber 102, first fuel pipe 20, second fuel pipe 30, air inlet hole 40, first air inlet hole 401, second air inlet hole 402, mounting plate 50, first incident hole 501, second incident hole 502, mounting flange 60. DETAILED DESCRIPTION

[0035] The present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only intended to enable those skilled in the art to better understand and implement the present invention, rather than to imply any limitation on the scope of the present invention.

[0036] As used herein, the term "including" and variations thereof are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment."

[0037] Figure 1 A perspective view schematically showing a dual fuel air premixing nozzle according to an embodiment of the present invention, Figure 2 A top view schematically showing a dual fuel air premixing nozzle according to one embodiment of the present invention, Figure 3 Schematically shows an embodiment of the present invention Figure 2 The cross-sectional view in the A-A' direction is as follows: Figure 1-3 As shown, a dual fuel air premixing nozzle of the present invention comprises:

[0038] The nozzle body 10 includes a first fuel pipe 20, a second fuel pipe 30, a first fuel channel 1011, a second fuel channel 1012, an air inlet hole 40, and a mounting plate 50. The mounting plate 50 is disposed within the nozzle body 10 and separates the fuel chamber 101 from the mixing chamber 102. The air inlet hole 40 is disposed on the outer wall of the mixing chamber 102.

[0039] The mounting plate 50 is provided with a first inlet hole 501 communicating with the mixing chamber 102 and the first fuel channel 1011 , and a second inlet hole 502 communicating with the mixing chamber 102 and the second fuel channel 1012 ;

[0040] The first incident hole 501 and the second incident hole 502 are arranged alternately, and preferably, the first incident hole 501 and the second incident hole 502 are arranged orthogonally.

[0041] Specifically, traditional gas turbines have poor fuel adaptability in their combustion chamber nozzles, which cannot accommodate the diverse energy sources of today. In addition to natural gas, they are also unable to handle hydrogen, ammonia, and even a large amount of industrial by-product gas, associated gas from oil fields, and biomass energy, resulting in a serious waste of energy.

[0042] The present invention provides a first fuel pipe 20 and a second fuel pipe 30 on the nozzle body 10, so that the nozzle can simultaneously blend multiple fuels to achieve mixed use of fuels. It can be applied to a variety of contemporary energy types and different scenarios. At the same time, for the case where the main fuel is natural gas and the secondary fuel is clean energy such as hydrogen, the proportion of natural gas can be appropriately reduced after blending, saving resources, and at the same time reducing the generation of pollutants, thereby reducing pollutant emissions and protecting the environment.

[0043] At the same time, the present invention provides a mounting plate 50 in the nozzle body 10, which can separate the internal space of the nozzle body 10, thereby achieving a better internal fluid structure and improving the mixing effect;

[0044] In conventional technology, the nozzle is connected to the gas turbine, and the igniter is located in the combustion chamber. The fuel is ejected from the nozzle into the combustion chamber and ignited by the igniter for combustion. The flow field and concentration distribution of the airflow ejected from the nozzle are directly related to the working performance of the combustion chamber. In the present invention, a first inlet hole 501 and a second inlet hole 502 are provided on the mounting plate 50, and the first inlet hole 501 and the second inlet hole 502 are arranged orthogonally, so that the two ejected fuel jets intersect, enabling better mixing, so that the flow field and uniformity of the two fuels located downstream are consistent, which is beneficial to subsequent fuel combustion and also makes it easier to control the equivalence ratio distribution of the two fuels.

[0045] Furthermore, since the flow rate of the main fuel is generally greater than that of the secondary fuel during use, the main fuel can guide the secondary fuel after being ejected from the inlet hole, thereby increasing the jet velocity of the secondary fuel and reducing the possibility of flashback.

[0046] Furthermore, the nozzle body 10 is provided with a first fuel channel 1011 and a second fuel channel 1012 which are independent of each other;

[0047] The first fuel channel 1011 has two ends connected to the first fuel pipe 20 and the first injection hole 501 respectively;

[0048] Two ends of the second fuel channel 1012 are connected to the second fuel pipe 30 and the second injection hole 502 respectively.

[0049] Specifically, in an embodiment of the present invention, the first fuel pipe 20 and the second fuel pipe 30 are coaxially arranged, and the first fuel pipe 20 is arranged on the central axis of the nozzle body 10;

[0050] The first fuel pipe 20 is inserted inward from the outside of the nozzle body 10 and extends to the mounting plate 50, and is fixed and sealed to the mounting plate 50. A first fuel channel 1011 is formed in the first fuel pipe 20, and the first fuel channel 1011 is connected to the first inlet hole 501. The first fuel enters the first fuel channel 1011 through the first fuel pipe 20 and is ejected through the first inlet hole 501.

[0051] Inside the nozzle body 10, the space enclosed by the outer wall of the first fuel pipe 20, the mounting plate 50 and the inner wall of the nozzle body 10 is the second fuel channel 1012. The second fuel channel 1012 wraps around the first fuel channel 1011, one side of which is connected to the second fuel pipe 30, and the other side is connected to the second inlet hole 502 on the mounting plate 50. The second fuel enters the second fuel channel 1012 through the second fuel pipe 30 and is finally ejected through the second inlet hole 502.

[0052] With such a configuration, since the flow rate of the fuel just ejected from the fuel pipe is small, the fuel airflow in contact with the air is uneven and asymmetric, and better mixing cannot be performed. The present invention improves the internal structure of the nozzle body 10 to form a first fuel channel 1011 and a second fuel channel 1012, so that after the fuel enters the nozzle body 10, it will not be directly mixed with the air, but the airflow will be stabilized in the channel first, and then ejected from the first inlet hole 501 or the second inlet hole 502. In this way, the fuel can be guaranteed to have better initial uniformity when it is ejected, thereby improving the stability of subsequent combustion and avoiding the backfire problem.

[0053] Furthermore, the second incident hole 502 is disposed close to the air inlet hole 40 .

[0054] Specifically, if Figure 3 As shown, the air inlet 40 is located on the right side of the mounting plate 50, and the first fuel channel 1011 and the second fuel channel 1012 are located on the left side of the mounting plate 50. In an embodiment of the present invention, the first fuel pipe 20 is located on the central axis of the nozzle body 10, so that there are two crossing modes between the first inlet hole 501 and the second inlet hole 502. The first is that the first inlet hole 501 is in the axial direction and the second inlet hole 502 is in the radial direction. In this way, after the fuel is ejected through the two inlet holes, it will be staggered and mixed in the middle area of ​​the nozzle body 10, and the second inlet hole 502 is arranged closer to the air inlet 40, so that the mixing area of ​​the two fuels is closer to the range of the air inlet hole 40, and can contact with the air faster for mixing.

[0055] In the second embodiment of the present invention, the first inlet hole 501 is in the radial direction and the second inlet hole 502 is in the axial direction. Compared with the first embodiment, this method makes the intersection area of ​​the two fuels after being ejected closer to the air inlet hole 40, and can be mixed with the air faster than the first embodiment, thereby improving the mixing effect. In addition, the second inlet hole 502 is set close to the air inlet hole 40, that is, closer to the inner wall of the nozzle body 10, so that the fuel and the air are closer. When the air just flows out of the air inlet hole 40, its flow rate is the largest. When the horizontally moving fuel contacts the vertically moving air, the closer the contact area is to the air inlet hole 40, the greater the impact force of the air, which can further increase the mixing effect.

[0056] At the same time, in the above-mentioned second embodiment, further, the outer wall of the nozzle body 10 is set at the second inlet hole 502, which can make the fuel ejected from the second inlet hole 502 closer to the air inlet hole 40. At the same time, the intersection of the two fuels is also closer to the air inlet hole 40, which can further contact with the air and achieve better mixing.

[0057] Furthermore, the air inlet hole 40 includes a first air inlet hole 401 and a second air inlet hole 402, so that the nozzle of the present invention can achieve two-layer air entry, increase the air intake area on the nozzle body 10, and thereby increase the air intake volume, improve the mixing effect of fuel and air in the nozzle body 10, and reduce pressure loss.

[0058] Furthermore, the first air inlet hole 401 is disposed close to the mounting plate 50 , and an opening area of ​​the first air inlet hole 401 is larger than an opening area of ​​the second air inlet hole 402 .

[0059] Specifically, the first air inlet hole 401 and the second air inlet hole 402 can be set to be approximately circular, or other shapes, and the first air inlet hole 401 and the second air inlet hole 402 are evenly distributed along the circumference of the side wall of the nozzle body 10, which can effectively utilize the air intake area on the side wall of the nozzle body 10;

[0060] Since the opening size of the first air inlet hole 401 is larger than the opening size of the second air inlet hole 402, and the first air inlet hole 401 is arranged close to the mounting plate 50, the fuel sprayed through the first inlet hole 501 and the second inlet hole 502 can be mixed with a large amount of air at the first time, thereby improving the mixing effect.

[0061] Furthermore, the openings of the first air inlet hole 401 and the second air inlet hole 402 are configured as radially oblique openings.

[0062] The first air inlet hole 401 and the second air inlet hole 402 are obliquely cut in opposite directions.

[0063] In conventional technology, in order to achieve faster and better mixing of air and fuel, a swirler is separately provided in the mixing section to cause the gas to swirl, thereby achieving a "stirring" effect, accelerating the mixing rate, and improving the mixing effect of air and fuel. However, the separately provided swirler increases the weight of the igniter nozzle, makes the safety structure inside the nozzle more complicated, reduces the reliability of the product, and increases the manufacturing cost.

[0064] In the present invention, however, the second air inlet 402 is designed as a radially beveled opening. This allows high-pressure air from outside the nozzle to enter the nozzle body 10 along the radially beveled surface, creating a swirling flow within the nozzle around the axis. This means that the second air inlet 402, through its own structure, can produce the same swirling effect as a swirler, simplifying the nozzle structure, reducing its weight, improving its reliability, and lowering its manufacturing and maintenance costs.

[0065] On this basis, the present invention also sets the opening of the first air inlet hole 401 as a radial beveled opening, and sets the bevel directions of the first air inlet hole 401 and the second air inlet hole 402 to be opposite. When the air enters the nozzle from the first air inlet hole 401, the swirl direction formed is opposite to the swirl direction formed after the air enters from the second air inlet hole 402. On the one hand, the nozzle utilizes the shear force of the airflow to further enhance the mixing of fuel and air. On the other hand, the airflow can return to the axial direction after passing through two layers of swirl, ensuring the circumferential mixing effect while making the airflow jet along the axial direction, which can improve the flow field performance.

[0066] Furthermore, the bevel angle of the radial bevel opening is in the range of 20°-40°, and the swirl generated within this range can achieve the best mixing effect of air and fuel.

[0067] Furthermore, the first air inlet hole 401 and the second air inlet hole 402 are set as key-shaped holes. Through this setting, the occupied area of ​​the first air inlet hole 401 and the second air inlet hole 402 in the circumferential direction of the side wall of the nozzle body 10 can be reduced, thereby increasing the number of the first air inlet holes 401 and the second air inlet holes 402, thereby increasing the amount of air entering the nozzle body 10. At the same time, more radially beveled first air inlet holes 401 and second air inlet holes 402 can also provide a better swirl flow field effect, thereby enhancing the mixing effect of air and fuel.

[0068] At the same time, if the number of the first air inlet holes 401 and the second air inlet holes 402 is set to be the same, the mixing effect can be further enhanced, the uniformity of the fuel at the nozzle outlet can be ensured, and better smoothness performance can be obtained.

[0069] Furthermore, a mounting flange 60 is provided on the side wall of the nozzle body 10 , so that the nozzle of the present invention is fixedly connected to the gas turbine via the mounting flange 60 .

[0070] To achieve the above object, the present invention also provides a gas turbine, which is applied to the above-mentioned dual-fuel air premixing nozzle.

[0071] In summary, according to the solution of the present invention, a mounting plate 50 is provided within the nozzle body 10. The mounting plate 50 divides the internal space of the nozzle body 10. A first inlet hole 501 and a second inlet hole 502 are provided on the mounting plate 50. The first inlet hole 501 and the second inlet hole 502 are arranged alternately, and the two jets ejected intersect with each other. This allows for better pre-mixing of the two fuel jets, maintains consistency in the flow field and uniformity of the two fuels downstream, achieves better mixing with air, and also makes it easier to control the equivalence ratio distribution of the two fuels.

[0072] In addition, since the dual fuel contains a main fuel and a secondary fuel, the flow rate of the secondary fuel is relatively small. After the main fuel is ejected through the injection hole, it can guide the secondary fuel, increase the jet velocity of the secondary fuel, and reduce the possibility of flashback.

[0073] The present invention further provides a first fuel channel 1011 and a second fuel channel 1012 within the nozzle body 10. The first fuel channel 1011 is connected to the first fuel pipe 20, and the second fuel channel 1012 is connected to the second fuel pipe 30. This allows the fuel to first be stabilized within the channels after entering the channels, resulting in better initial uniformity when the fuel is ejected through the inlet, thereby improving the mixing effect, making combustion more stable, and avoiding the problem of flashback.

[0074] At the same time, the first air inlet hole 401 and the second air inlet hole 402 are both set as radial beveled openings, and the bevel directions of the two are set in opposite directions. On the one hand, the shear force of the airflow can be used to further enhance the mixing of fuel and air. On the other hand, through the two-stage swirl, the airflow can be returned to the axial direction, ensuring the circumferential mixing effect while making the airflow jet along the axial direction, thereby improving the flow field performance.

[0075] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

[0076] It should be understood that the size of the serial numbers of each step in the content of the invention and the embodiments of the present invention does not absolutely mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A dual fuel air premixing nozzle, characterized in that: include: The nozzle body includes a first fuel pipe, a second fuel pipe, a first fuel channel, a second fuel channel, an air inlet hole, and a mounting plate provided on the nozzle body. The mounting plate is provided inside the nozzle body and separates a fuel chamber and a mixing chamber inside the nozzle body. The air inlet hole is provided on the outer wall of the mixing chamber. The mounting plate is provided with a first inlet hole communicating with the mixing chamber and the first fuel channel, and a second inlet hole communicating with the mixing chamber and the second fuel channel; The first inlet hole and the second inlet hole are arranged orthogonally, the first inlet hole is located between the air inlet hole and the first fuel channel, and the second inlet hole is located between the air inlet hole and the second fuel channel; The air inlet hole includes a first air inlet hole and a second air inlet hole; The first air inlet hole is arranged close to the mounting plate, and an opening area of ​​the first air inlet hole is larger than an opening area of ​​the second air inlet hole; The openings of the first air inlet hole and the second air inlet hole are configured as radially oblique openings, and the oblique directions of the first air inlet hole and the second air inlet hole are opposite; The first fuel channel coincides with the central axis of the nozzle body, and the second fuel channel wraps around the first fuel channel; A first inlet hole is radially arranged on the first fuel channel, and a second inlet hole is axially arranged on the second fuel channel; The first air inlet holes and the second air inlet holes are evenly arranged along the circumference of the side wall of the nozzle body.

2. A dual fuel air premixing nozzle according to claim 1, characterized in that: The bevel angle of the radial bevel opening is in the range of 20°-40°.

3. The dual fuel air premixing nozzle according to claim 1, characterized in that: The first air inlet hole and the second air inlet hole are configured as key-shaped holes.

4. The dual fuel air premixing nozzle according to claim 1, characterized in that: The second incident hole is arranged close to the outer wall of the nozzle body.

5. The dual fuel air premixing nozzle according to claim 1, characterized in that: The number of the first air inlet holes and the number of the second air inlet holes are the same.

6. The dual fuel air premixing nozzle according to claim 1, characterized in that: A mounting flange is provided on the side wall of the nozzle body.

7. A gas turbine, characterized in that: The dual fuel air premixing nozzle comprises the dual fuel air premixing nozzle according to any one of claims 1 to 6.

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