Micro mixing nozzle, combustor and gas turbine

Abstract

The invention discloses a micro-mixing nozzle, a combustor and a gas turbine, the micro-mixing nozzle comprises a nozzle main body, a micro-mixing channel, a fuel cavity and a fuel channel communicated with the fuel cavity are arranged in the nozzle main body, and a plurality of micro-mixing pipe sections with micro-mixing channels are arranged in the fuel cavity; a communicating hole for communicating the micro-mixing channel with the fuel cavity is formed in the pipe wall of each micro-mixing pipe section, the micro-mixing channel is provided with an air inlet and a fuel gas outlet, and fuel entering from the communicating hole and air entering from the air inlet are mixed in the micro-mixing channel and then sprayed out from the fuel gas outlet. According to the scheme provided by the invention, the mixing effect of fuel and air in the micro-mixing nozzle can be enhanced, rapid and uniform mixing of the fuel and the air can be realized under the condition of high flow speed, the combustion stability is remarkably improved, and the emission of pollutants is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of gas turbines, and in particular to a micro-mixing nozzle, a burner and a gas turbine. Background Art

[0002] Gas turbines are one of the important equipment for clean utilization of fossil energy and are widely used in power generation, aviation, industrial power and other fields. In addition, gas turbines are also ideal equipment for hydrogen energy conversion, which can effectively convert hydrogen energy into mechanical energy. With the increasing global attention to sustainable development and low-carbon protection, the country's pollutant emission standards for gas turbines are also becoming increasingly stringent. Technologies to reduce nitrogen oxide (NOx) emissions play a key role in improving the market competitiveness of gas turbines.

[0003] There are three main mechanisms for the generation of NOx: thermal, fuel, and rapid. In gas turbines that use clean energy such as natural gas and hydrogen as the main fuel, the generation of thermal NOx is dominant. To control the generation of thermal NOx, traditional solutions include introducing diluents such as nitrogen or water vapor through diffusion combustion, but this method is often accompanied by problems such as increased equipment complexity and increased control difficulty. The lean premixing scheme can effectively reduce the flame temperature and thus reduce NOx emissions, but when using some highly active fuels (such as hydrogen-rich fuels or pure hydrogen), the flame temperature is high and the flame speed is fast, and the air speed in the nozzle needs to reach more than 100 m / s to prevent flashback. However, traditional mixing nozzles often find it difficult to achieve rapid and uniform mixing of fuel and air under such high flow conditions, which in turn affects safety and emission characteristics.

[0004] Therefore, there is an urgent need to develop new nozzles to solve the current problems existing in the combustion of gas turbines. Summary of the invention

[0005] The embodiments of the present application provide a micro-mixing nozzle, a burner and a gas turbine to solve the problems existing in the combustion of current gas turbines.

[0006] An embodiment of the present application provides a micro-mixing nozzle, including a nozzle body, wherein a micro-mixing channel, a fuel cavity and a fuel channel connected to the fuel cavity are arranged in the nozzle body, a plurality of micro-mixing tube segments each having the micro-mixing channel are arranged in the fuel cavity, a connecting hole connecting the micro-mixing channel with the fuel cavity is arranged on the tube wall of each of the micro-mixing tube segments, the micro-mixing channel having an air inlet and a gas outlet, the fuel entering from the connecting hole and the air entering from the air inlet are mixed in the micro-mixing channel and then ejected from the gas outlet.

[0007] In one embodiment, each of the micro-mixing tube segments is provided with at least one group of communicating holes, and each group of communicating holes includes a plurality of communicating holes that are located at the same height position of the micro-mixing tube segment and are spaced apart along the circumferential direction.

[0008] In one embodiment, the injection angle of at least one group of the communicating holes is set so that a swirl is formed when the fuel is injected from the group of communicating holes into the micro-mixing channel.

[0009] In one embodiment, each group includes four of the communicating holes.

[0010] In one embodiment, a fuel pipe having the fuel channel is provided on the nozzle body, and the fuel pipe includes an extended pipe section extending into the fuel cavity, so that the gas transported to the fuel cavity by the fuel channel flows back from bottom to top and enters the connecting hole.

[0011] In one embodiment, at the jet end of the nozzle body, the external space corresponding to the intervals between the plurality of gas outlets forms a flame recirculation zone.

[0012] An embodiment of the present application also provides a combustor, comprising at least one micro-mixing nozzle as described above.

[0013] An embodiment of the present application also provides a gas turbine, comprising the combustor as described above.

[0014] In the technical solution provided by the embodiment of the present application, the micro-mixing nozzle is provided with a fuel cavity, and a plurality of micro-mixing tube segments are located in the fuel cavity, so that the fuel in the fuel cavity enters the micro-mixing channel through the connecting holes provided on the micro-mixing tube segments, and the fuel can be mixed with the air entering the micro-mixing channel. This mixing method can not only improve the mixing effect of the fuel and the air, but also can achieve rapid and uniform mixing of the fuel and the air under high flow rate conditions, significantly improve the stability and efficiency of combustion, and reduce the spontaneous combustion and flashback caused by uneven fuel concentration. In addition, the uniform fuel-air mixture can achieve more efficient combustion and can reduce the peak flame temperature during the combustion process, thereby achieving an effective reduction effect of harmful NOx emissions.

[0015] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0017] Figure 1 is a schematic structural diagram of a micro-mixing nozzle according to an embodiment of the present application; Figure 2 for Figure 1 A schematic diagram of the longitudinal cross-section structure of the micro-mixing nozzle; Figure 3 for Figure 1 Another longitudinal cross-sectional structural schematic diagram of the micro-mixing nozzle; Figure 4 for Figure 1 Schematic diagram of the transverse cross-section structure of the micro-mixing nozzle; Figure 5 Schematic diagram of the structure of a micro-mixing pipe section according to an embodiment of the present application.

[0018] 1-nozzle body; 11-fuel cavity; 12-fuel channel; 13-fuel pipe; 131-extension pipe section; 132-connecting pipe section; 14-micro-mixing channel; 141-air inlet; 142-gas outlet; 15-micro-mixing pipe section; 151-connecting hole. DETAILED DESCRIPTION

[0019] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0020] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0021] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0022] The embodiment of the present application provides a micro-mixing nozzle for a gas turbine, such as Figure 1-Figure 3 As shown, the nozzle body 1 includes a micro-mixing channel 14, a fuel cavity 11 and a fuel channel 12 connected to the fuel cavity 11. The fuel cavity 11 includes a plurality of micro-mixing tube segments 15 each having a micro-mixing channel 14. A connecting hole 151 connecting the micro-mixing channel 14 with the fuel cavity 11 is provided on the tube wall of each micro-mixing tube segment 15. The micro-mixing channel 14 has an air inlet 141 and a gas outlet 142. The fuel entering from the connecting hole 151 and the air entering from the air inlet 141 are mixed in the micro-mixing channel 14 and then ejected from the gas outlet 142.

[0023] The micro-mixing nozzle provided in the embodiment of the present application is provided with a fuel cavity 11, and a plurality of micro-mixing tube segments 15 are located in the fuel cavity 11, so that the fuel in the fuel cavity 11 enters the micro-mixing channel 14 through the connecting hole 151 provided on the micro-mixing tube segment 15, thereby achieving the mixing of the fuel and the air entering the micro-mixing channel 14. This mixing method can enhance the mixing effect of the fuel and the air, and can achieve rapid and uniform mixing of the fuel and the air under high flow rate conditions, significantly improve the stability and efficiency of combustion, and reduce the spontaneous combustion and flashback caused by uneven fuel concentration. In addition, the uniform fuel-air mixture can achieve more efficient combustion and can reduce the peak flame temperature during the combustion process, thereby achieving an effective reduction effect of harmful NOx emissions.

[0024] In one embodiment, at least one group of connecting holes 151 is provided on each micro-mixing tube segment 15, and each group of connecting holes 151 includes a plurality of connecting holes 151 arranged at the same height position of the micro-mixing tube segment 15 and spaced apart along the circumferential direction. Since the fuel at different positions in the fuel cavity 11 may have different pressures, a plurality of connecting holes 151 are spaced apart along the circumferential direction on each micro-mixing tube segment 15, so that the fuel in the fuel cavity 11 can enter the micro-mixing tube segment 15 from different directions, which is beneficial to improving the uniformity of the fuel entering each micro-mixing tube segment 15.

[0025] In one example, the injection angle of at least one group of communication holes 151 is set so that a swirl is formed when the fuel is injected into the micro-mixing channel 14 from the group of communication holes 151. The swirl formed by injecting the fuel into the micro-mixing channel 14 can enhance the mixing effect with the air flowing in the micro-mixing channel 14, so that the fuel and the air in the micro-mixing channel 14 are fully mixed.

[0026] like Figure 4 and Figure 5 In the example, each micro-mixing tube segment 15 is provided with a group of communicating holes 151, each group of communicating holes 151 is provided with four communicating holes 151, and the hole depth direction of each communicating hole 151 (the hole depth direction determines the injection direction of the hole) deviates from the radial direction of the micro-mixing tube segment 15, that is, the multiple communicating holes 151 in each group form a roughly spiral arrangement, so that the fluid injected into the micro-mixing channel 14 by the multiple communicating holes 151 can form a swirl.

[0027] It is understandable that each micro-mixing tube segment 15 may be provided with multiple groups of communication holes 151, not limited to one group, and each group may be provided with three or five or other numbers of communication holes 151. In addition, the communication holes 151 may also be arranged in other ways, not limited to the arrangement described in the above embodiment.

[0028] In one embodiment, Figure 1-Figure 3 As shown, the nozzle body 1 is provided with a fuel pipe 13 having a fuel channel 12, and the fuel pipe 13 includes an extended pipe section 131 extending into the fuel cavity 11, so that the gas transported to the fuel cavity 11 by the fuel channel 12 flows back from bottom to top and enters the connecting hole 151. Here, up and down are defined according to the upstream and downstream of the gas transport direction of the fuel channel 12, and the position located relatively upstream is defined as "up".

[0029] By setting the extension pipe section 131, the fuel can be directed to a certain position in the fuel chamber 11, and then the fuel flows back from the bottom to the top at the position in the fuel chamber 11 and then enters the connecting hole 151. Because the refluxed fuel can be more evenly distributed at various positions in the fuel chamber 11, the pressure in the fuel chamber 11 is uniform, so that the fuel can be evenly distributed to multiple micro-mixing channels 14 to prevent local rich or lean combustion. The length of the extension pipe section 131 can be set so that the extension pipe section 131 extends to a certain distance from the bottom of the fuel chamber 11, or the outlet of the extension pipe section 131 exceeds a certain distance from the connecting hole 151 in the gas delivery direction of the fuel channel 12.

[0030] The fuel pipe 13 may further include a connecting pipe section 132 connected to the extending pipe section 131 , and the connecting pipe section 132 may be conveniently connected to a fuel supply device.

[0031] At the jet end of the nozzle body 1, the external space corresponding to the intervals between the multiple gas outlets 142 forms a flame recirculation zone. That is, during the combustion process, after the multiple gas outlets 142 eject combustion gas for combustion, the external space corresponding to the intervals between the gas outlets 142 is the space between the multiple gas flows ejected from each gas outlet 142, and this space is a flame recirculation zone where the flame can recirculate. After the combustion gas ejected from the gas outlet 142 is burned, the flame recirculates to the flame recirculation zone to further ignite the ejected combustion gas, which can help stabilize the combustion flame and prevent flashback.

[0032] The embodiment of the present application also provides a burner, comprising at least one micro-mixing nozzle as described above. The burner provided by the present application can achieve efficient combustion and reduce the emission of harmful substances by adopting the micro-mixing nozzle as described above.

[0033] An embodiment of the present application also provides a gas turbine, comprising the combustor as described above.

[0034] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include at least one of the features.

[0036] In the description of the present application, “plurality” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0040] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A micro-mixing nozzle for a gas turbine, characterized in that: The nozzle body comprises a micro-mixing channel, a fuel cavity and a fuel channel connected with the fuel cavity, the fuel cavity is provided with a plurality of micro-mixing tube segments respectively having the micro-mixing channels, a tube wall of each micro-mixing tube segment is provided with a connecting hole connecting the micro-mixing channel with the fuel cavity, the micro-mixing channel has an air inlet and a gas outlet, the fuel entering from the connecting hole and the air entering from the air inlet are mixed in the micro-mixing channel and then ejected from the gas outlet.

2. The micro-mixing nozzle according to claim 1, characterized in that: Each of the micro-mixing tube segments is provided with at least one group of communicating holes, and each group of communicating holes includes a plurality of communicating holes which are arranged at the same height position of the micro-mixing tube segment and are spaced apart along the circumferential direction.

3. The micro-mixing nozzle according to claim 2, characterized in that: The injection angle of at least one group of the communicating holes is set so that a swirl is formed when the fuel is injected from the group of communicating holes into the micro-mixing channel.

4. The micro-mixing nozzle according to claim 2, characterized in that: Each group includes four communicating holes.

5. The micro-mixing nozzle according to claim 1, characterized in that: The nozzle body is provided with a fuel pipe having the fuel channel, and the fuel pipe includes an extended pipe section extending into the fuel cavity, so that the gas transported to the fuel cavity by the fuel channel flows back from bottom to top and enters the connecting hole.

6. The micro-mixing nozzle according to any one of claims 1 to 5, characterized in that: At the jetting end of the nozzle body, the outer space corresponding to the intervals between the plurality of gas outlets forms a flame recirculation zone.

7. A burner, characterized in that: The method comprises at least one micro-mixing nozzle according to any one of claims 1 to 6.

8. A gas turbine, characterized in that: Comprising a burner according to claim 7.

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