Gas premix combustion nozzle and combustor

Abstract

The application discloses a gas premixing combustion nozzle and a combustor, and relates to the technical field of gas turbines. The premixing unit comprises a mounting seat, a feeding assembly arranged on the mounting seat, and an air inlet assembly arranged in the same cavity as the feeding assembly. The air is regulated by the air grid to obtain uniform airflow. The airflow is uniformly integrated with the multiple fuel streams passing through the injection column during the movement of the airflow in the protection shell towards the bluff body. When the premixed gas passes through the bluff body, the peripheral surface of the bluff body and the gas flow rate behind the bluff body are different, so that a backflow area is generated behind the bluff body. At this time, the high-temperature flue gas downstream of the flame is sucked into the upstream area of the flame by the backflow, which provides a continuous high-temperature ignition source for the fresh combustible premixed gas, and avoids the safety hazards caused by the high-temperature air entering the premixing pipeline.

Description

Technical Field

[0001] This invention relates to the technical field of gas turbines, and more particularly to a gas premixed combustion nozzle and burner. Background Technology

[0002] Premixed combustion refers to the combustion of pre-mixed fuel and oxidizer in a specific area, applicable to various fields such as production, daily life, and energy. Its application is extremely widespread. This combustion method is cleaner and more efficient than diffusion combustion, where fuel and oxidizer are mixed and burned simultaneously. In many premixed combustion experiments, to ensure a high level of mixing between fuel and air, researchers often install long pipes or mixing devices upstream of the burner to pre-mix the fuel and oxidizer. However, these lengthy pipes or mixing devices not only increase the complexity of the experimental system but also introduce additional safety risks. For example, if a premixed flame flashback occurs, the flame may propagate back into the premixed gas pipes or mixing device, posing a certain safety hazard.

[0003] Therefore, it is necessary to provide a design that eliminates lengthy mixing lines or any mixing devices, and completes the mixing process of fuel and oxidant within the burner. Summary of the Invention

[0004] In view of the problems existing in the above-mentioned gas premixed combustion nozzles, the first embodiment of the present invention is proposed.

[0005] Therefore, the purpose of this invention is to provide a gas premixed combustion nozzle, which aims to solve the technical problem of safety hazards caused by the long pipelines or gas mixing devices upstream of the burner.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a gas premixed combustion nozzle, comprising a premixing unit, including a mounting base, a feeding assembly disposed on the mounting base, and an air inlet assembly whose outlet end is located in the same cavity as the feeding assembly;

[0007] The premixing unit has one and only its feed assembly connected to the burner.

[0008] As a preferred embodiment of the gas premixed combustion nozzle of the present invention, the feeding assembly includes a feeding pipe disposed on the mounting base, an injection column surrounding the outer surface of the feeding pipe, a blunt body disposed at the top end of the feeding pipe, and a protective housing disposed at the end of the injection column away from the feeding pipe.

[0009] In a preferred embodiment of the gas premixed combustion nozzle of the present invention, the blunt body is configured as a funnel shape, and the diameter of the blunt body at one end near the mounting base is smaller than the diameter of the other end of the blunt body.

[0010] As a preferred embodiment of the gas premixed combustion nozzle of the present invention, the air intake assembly includes an air intake pipe disposed on the outside of the protective housing, and an air grille disposed on the outside of the feed pipe and located inside the protective housing.

[0011] In a preferred embodiment of the gas premixed combustion nozzle of the present invention, the air intake pipe and the injection column are symmetrically arranged with the straight line containing the air grid plane as the axis.

[0012] As a preferred embodiment of the gas premixed combustion nozzle of the present invention, the injection column is arranged in a circumferential array along the center of the feed pipe, and the injection column includes two sets of feed holes with the same diameter opened on the surface of the injection column and parallel to the mounting base, a diversion hole with a diameter smaller than the feed hole diameter disposed between the two sets of feed holes, and a reverse feed hole symmetrically arranged with respect to the feed hole and the axis of the injection column.

[0013] As a preferred embodiment of the gas premixed combustion nozzle of the present invention, wherein: the surface of the air grid is uniformly and equidistantly provided with rectifying holes with a diameter larger than that of the feed hole.

[0014] The beneficial effects of this invention are as follows: By setting an air grid to rectify the air, a uniform airflow is obtained. As the airflow moves towards the blunt body in the protective shell, it is uniformly mixed with multiple streams of fuel passing through the injection column. When the premixed gas passes through the blunt body, the gas velocity on the outer surface of the blunt body and behind the blunt body is different, thus creating a backflow zone behind the blunt body. At this time, the high-temperature flue gas downstream of the flame will be drawn back to the upstream area of ​​the flame. This provides a continuous high-temperature ignition source for fresh combustible premixed gas, while avoiding the safety hazards caused by high-temperature air entering the premixed pipe.

[0015] In view of the problems existing in the above-mentioned burners with gas premixed combustion nozzles, a second embodiment of the present invention is proposed.

[0016] Therefore, the present invention provides a burner with a gas premixed combustion nozzle, the purpose of which is to solve the technical problem of safety hazards caused by the long pipeline or gas mixing device upstream of the fuel burner.

[0017] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including a burner body unit;

[0018] A burner connection unit connected to the burner body unit; and,

[0019] The filtration unit includes a filter plate disposed between the burner body unit and the burner connection unit.

[0020] As a preferred embodiment of the burner with a gas premixed combustion nozzle according to the present invention, the burner connection unit is provided with a fixing block, and the feed pipe is provided with a mounting hole corresponding to the fixing block.

[0021] In a preferred embodiment of the burner with a gas premixed combustion nozzle according to the present invention, the diameter of the feed hole is 0.5 to 3 mm.

[0022] The beneficial effects of this invention are: by adjusting the diameter of the feed hole, the fuel injection amount can be controlled to adapt to different combustion requirements, thereby optimizing fuel consumption and combustion efficiency. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0024] Figure 1 This is a schematic diagram of the overall structure of the gas premixed combustion nozzle of the present invention.

[0025] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle.

[0026] Figure 3 This is a schematic diagram of the injection column structure of the gas premixed combustion nozzle of the present invention.

[0027] Figure 4 This is an exploded view of the burner with a gas premixed combustion nozzle according to the present invention.

[0028] Figure 5 This is a schematic diagram of the overall structure of the burner with a gas premixed combustion nozzle according to the present invention. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0031] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0032] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0033] Example 1

[0034] Reference Figure 1 The first embodiment of the present invention provides a gas premixed combustion nozzle, including a premixing unit 100. The premixing unit 100 includes a mounting base 101, a feeding assembly 102 disposed on the mounting base 101, and an air inlet assembly 103 located in the same cavity as the air outlet m and the feeding assembly 102. The premixing unit 100 has only its feeding assembly 102 connected to the burner.

[0035] Furthermore, the feeding assembly 102 includes a feeding pipe 102a disposed on the mounting base 101, a jet column 102b surrounding the outer surface of the feeding pipe 102a, a blunt body 102c disposed at the top end of the feeding pipe 102a, and a protective housing 102d disposed at the end of the jet column 102b away from the feeding pipe 102a.

[0036] During use, fuel enters the injection column 102b through the feed pipe 102a and is sprayed out into the protective housing 102d through the injection column 102b. It is then mixed with the air or combustion accelerant that enters the protective housing 102d through the air intake assembly 103. The premixed gas is ignited when it passes through the blunt body 102c. At the same time, the presence of the blunt body 102c makes the flame more stable. This invention uses the protective housing 102d to replace the long premixed pipe or device, avoiding the safety risk of backfiring into the premixed pipe when the premixed flame backfires.

[0037] Example 2

[0038] Reference Figures 1-3This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the blunt body 102c is configured as a funnel shape. The diameter of the blunt body 102c at one end near the mounting base 101 is smaller than the diameter of the other end of the blunt body 102c. When the premixed gas passes through the blunt body 102c, the outer surface of the blunt body 102c and the gas flow velocity behind the blunt body 102c are different. As a result, a backflow zone is generated behind the blunt body 102c, i.e., in the target direction of the premixed gas movement. At this time, the high-temperature flue gas downstream of the flame will be drawn back into the upstream region of the flame. This provides a continuous high-temperature ignition source for fresh combustible premixed gas, effectively saving resources and avoiding the fire or explosion risk of premixed flame backfire.

[0039] Compared to Embodiment 1, the intake assembly 103 further includes an intake pipe 103a disposed on the outside of the protective housing 102d, and an air grille 103b surrounding the feed pipe 102a and located inside the protective housing 102d. Air or combustion aid enters the protective housing 102d through the intake pipe 103a under the control of the flow meter, and is rectified when passing through the air grille 103b, so that the air or combustion aid airflow to the fuel is uniform, thereby improving the premixing efficiency.

[0040] Furthermore, the intake pipe 103a and the injection column 102b are symmetrically arranged with the straight line of the plane of the air grille 103b as the axis. After the air passes through the air grille 103b for rectification, it meets the fuel sprayed out by the injection column 102b. At this time, the airflow is uniform, the movement distance is short, and it has a high relative speed and power, which is conducive to better mixing with the fuel.

[0041] Furthermore, the injection columns 102b are arranged in a circumferential array along the center of the feed pipe 102a. The injection columns 102b include two sets of feed holes 102b-1 with the same diameter, parallel to the mounting base 101 on the surface of the injection column 102b; a diversion hole 102b-2 with a smaller diameter than the feed holes 102b-1, located between the two sets of feed holes 102b-1; and a reverse feed hole 102b-3 symmetrically arranged with respect to the axis of the injection column 102b with respect to the feed holes 102b-1. Fuel passes through the feed holes 102b-1, the diversion hole 102b-2, and the reverse feed hole 102b-3. 3. The fuel is ejected perpendicular to the airflow, increasing the contact area between the fuel and the air. The design of the diversion hole 102b-2 creates a pressure difference on both sides of the injection column 102b. At this time, the ejected fuel moves towards the side with lower pressure, effectively enhancing the movement of the fuel and promoting the mixing of fuel and air. At the same time, when using solid fuel, the different pressure on both sides effectively avoids blockage caused by solid fuel being ejected from the injection column 102b. Even if a discharge hole is blocked by fuel particles that are larger, it can be cleared by the continuous movement of the fuel under the action of different pressures.

[0042] Furthermore, the surface of the air grille 103b is uniformly and equidistantly provided with rectifier holes 103b-1 with a diameter larger than that of the feed hole 102b-1. The airflow column passing through the air grille 103b has a larger surface area than the fuel column, which is beneficial for the airflow column to entrain the fuel, thereby making the fuel and air mix evenly and improving the ignition efficiency when the premixed gas is ignited.

[0043] The remaining structure is the same as that in Example 1.

[0044] Example 3

[0045] Reference Figures 1-5 This is the third embodiment of the present invention, which is based on the first and second embodiments of the present invention, and provides a burner with a gas premixed combustion nozzle, including a burner body unit 500;

[0046] The burner connection unit 300 is connected to the burner body unit 500; and,

[0047] The filter unit 400 includes a filter plate 401 disposed between the burner body unit 500 and the burner connection unit 300. During operation, the filter plate 401 filters the fuel first, reducing the possibility of clogging the injection column 102b during subsequent fuel injection.

[0048] Compared to Embodiment 2, the burner connection unit 300 is further provided with a fixing block 301, and the feed pipe 102a is provided with a mounting hole 102a-1 corresponding to the fixing block 301, so that the filter unit 400 and the premixing unit 100 can be disassembled and replaced through the burner connection unit 300 under different combustion conditions and requirements.

[0049] The remaining structure is the same as that in Example 2.

[0050] Example 4

[0051] This embodiment, based on Embodiments 1 to 3 of the present invention, provides a method for using a burner, specifically as follows:

[0052] 1) Install the gas premixed combustion nozzle and connect it to the fuel supply system and air supply system.

[0053] 2) Using natural gas fuel at 1.57m 3 Air enters the feed pipe 102a at a flow rate of / h, and air flows at a rate of 15m. 3 A flow rate of / h enters the intake manifold 103a;

[0054] 3) Start the burner, observe the initial combustion, and ensure the flame is stable.

[0055] The flow meters are used to record the flow rates of fuel and air, the high-speed cameras are used to record the flame pattern, the thermocouples are used to measure the flame temperature distribution, the flue gas emission analyzers are used to measure the NOx emissions, and the pressure sensors are used to measure the pressure loss of fuel and air.

[0056] Combustion efficiency (%) = (Theoretical energy output / Actual energy output) × 100%;

[0057] Fuel consumption (m 3 = Flowmeter reading (m) 3 / h×time;

[0058] NOx emissions (ppm) = (NOx concentration (mg / m³)) 3 () / Standard air density (mg / L)×10 6 .

[0059] The diameters of the feed hole 102b-1 were set to 0.5, 1.0, 2.0 and 3.0 mm respectively. Each experiment was repeated three times, and the test results are shown in Table 1.

[0060] Table 1

[0061]

[0062] As shown in Table 1, under the condition that other conditions remain unchanged, as the diameter of the feed hole 102b-1 increases, the combustion efficiency and fuel consumption show an upward trend, while the NOx emission shows a trend of first increasing and then decreasing. This is because a smaller diameter can increase the surface area of ​​fuel injection, thereby improving the mixing efficiency of fuel and air and promoting faster and more uniform combustion. However, if the diameter is too small, it may lead to a decrease in injection speed and affect the mixing efficiency. At the same time, the size of the diameter will affect the distribution of combustion products, and thus affect the generation of pollutants.

[0063] Using natural gas fuel at 1.57m 3 Air enters the feed pipe 102a at a flow rate of / h, and air flows at a rate of 15m. 3 When a flow rate of / h enters the intake pipe 103a, the orifice diameter of the feed hole 102b-1 is selected to be 1.0mm. At this time, the NOx emission reaches the minimum, which is only 28ppm, while maintaining combustion efficiency and taking into account the system cost-effectiveness.

[0064] Gas premixed combustion nozzles with different orifice diameters can also provide a wider range of adjustment to adapt to different combustion conditions and requirements, thereby optimizing fuel consumption and combustion efficiency, and improving the adaptability and flexibility of the combustion system. By adjusting the orifice diameter, the nozzle can be adapted to fuels with different viscosities or combustion characteristics. Therefore, under different combustion conditions and working requirements, operators can select nozzles with different parameters according to the actual situation.

[0065] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0066] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the currently considered best mode for carrying out the invention, or those features that are not relevant to implementing the invention) may be omitted.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A gas premixed combustion nozzle, characterized in that: include, The premixing unit (100) includes a mounting base (101), a feeding assembly (102) disposed on the mounting base (101), and an air intake assembly (103) whose air outlet (m) is located in the same cavity as the feeding assembly (102). The premixing unit (100) has one and only its feed assembly (102) connected to the burner; The feeding assembly (102) includes a feeding pipe (102a) disposed on the mounting base (101), a jet column (102b) surrounding the outer surface of the feeding pipe (102a), a blunt body (102c) disposed at the top end of the feeding pipe (102a), and a protective shell (102d) disposed at the end of the jet column (102b) away from the feeding pipe (102a). The spray column (102b) is arranged in a circumferential array along the center of the feed pipe (102a). The spray column (102b) includes two sets of feed holes (102b-1) with the same diameter, which are opened on the surface of the spray column (102b) and parallel to the mounting base (101); a diversion hole (102b-2) with a diameter smaller than that of the feed holes (102b-1) is arranged between the two sets of feed holes (102b-1); and a reverse feed hole (102b-3) is arranged symmetrically with respect to the axis of the feed holes (102b-1) with respect to the axis of the spray column (102b). Fuel enters the injection column (102b) through the feed pipe (102a) and is sprayed out into the protective housing (102d) through the injection column (102b), where it is mixed with the air that enters the protective housing (102d) through the air intake assembly (103) in a vertical collision.

2. The gas premixed combustion nozzle according to claim 1, characterized in that: The blunt body (102c) is configured in a funnel shape, and the diameter of the blunt body (102c) at one end near the mounting base (101) is smaller than the diameter of the other end of the blunt body (102c).

3. The gas premixed combustion nozzle according to claim 2, characterized in that: The air intake assembly (103) includes an air intake pipe (103a) disposed outside the protective housing (102d) and an air grille (103b) disposed outside the feed pipe (102a) and located inside the protective housing (102d).

4. The gas premixed combustion nozzle according to claim 3, characterized in that: The air intake pipe (103a) and the injection column (102b) are symmetrically arranged with the straight line containing the plane of the air grille (103b) as the axis.

5. The gas premixed combustion nozzle according to claim 4, characterized in that: The air grille (103b) has rectifier holes (103b-1) with a diameter larger than that of the feed hole (102b-1) evenly spaced on its surface.

6. A gas premixed burner, characterized in that: Includes the gas premixed combustion nozzle as described in claim 5; Includes the burner body unit (500); A burner connection unit (300) connected to the burner body unit (500); and, The filter unit (400) includes a filter plate (401) disposed between the burner body unit (500) and the burner connection unit (300).

7. The burner according to claim 6, characterized in that: The burner connection unit (300) is provided with a fixing block (301), and the feed pipe (102a) is provided with a mounting hole (102a-1) corresponding to the fixing block (301).

8. The burner according to claim 7, characterized in that: The diameter of the feed hole (102b-1) is 0.5~3mm.

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