A structure of a burner port combination unit and a fully premixed burner

Abstract

The present invention relates to a burner port combination unit structure and a fully premixed burner. The burner port combination unit structure includes a burner port body, and the burner port body includes a frame wall; one or more main burner holes are provided on the burner port body; the main burner holes are conical holes; one or more flame stabilizing burner holes are provided on the frame wall of the burner port body; the flame stabilizing burner holes are rectangular strip holes; the area ratio of a single main burner hole to a single flame stabilizing burner hole is 1:0.3 - 1:0.4; the fully premixed burner includes a plurality of the above-mentioned burner port combination unit structures. Compared with the prior art, the present invention can prevent flashback when the fully premixed burner operates under the condition that the air-fuel ratio is greater than 1.2, can avoid the surface discoloration caused by too high a temperature of the burner port metal or the local flashback caused by too fast a flame propagation speed, thereby improving the stability of the fully premixed combustion, and can ensure the reduction of nitrogen oxide emissions while stably burning.

Description

Technical Field

[0001] The present invention relates to the technical field of fully premixed burners, and in particular to a flame port combination unit structure and a fully premixed burner. Background Art

[0002] The fully premixed burner is a highly efficient burner that emerged under the global emphasis on energy conservation. This type of burner can achieve a maximum efficiency of over 100% for gas appliances. However, while focusing on energy conservation, the world also attaches great importance to flue gas emissions and reducing air pollution. To meet emission and energy efficiency standards, various manufacturers have adopted the fully premixed combustion technology combined with the condensation technology. This is the most effective way to improve energy efficiency.

[0003] However, while improving energy efficiency, the emission requirements of nitrogen oxides must also be taken into account. Generally, the oxygen content in fully premixed combustion is controlled at 3% - 5%. The excess air coefficient is 1 - 1.15. Since the combustion temperature is higher than 1400°C, thermal nitrogen oxides are formed. If the excess air coefficient is increased to above 1.4, the generation of nitrogen oxides can be significantly reduced, but the burner structure must provide stable combustion conditions, which is a stable flame, and the flame does not lift off after increasing the air coefficient.

[0004] Therefore, there is an urgent need for a flame port structure that can improve the stability of fully premixed combustion and avoid flame lift-off during the operation of a fully premixed burner. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art and provide a flame port combination unit structure and a fully premixed burner. The flame port combination unit structure in this solution can enable the fully premixed burner to operate without flame lift-off under the condition that the air-fuel mixing ratio is greater than 1.2, but the flame is about 1.5 - 3 away from the main flame port surface. In this way, even if the flame temperature decreases, it can avoid the heat conduction of the flame temperature to the flame port metal material, resulting in too high a temperature of the flame port metal, causing surface discoloration or too fast a flame propagation speed, resulting in local flashback, thereby improving the stability of fully premixed combustion.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] The first purpose of the present invention is to provide a flame port combination unit structure, including a flame port body. The flame port body includes a frame wall, and the frame wall is the circumferential side wall of the flame port body. One or more main flame holes are provided on the flame port body. The main flame holes are conical holes to ensure the outlet speed of the mixed air-fuel gas. One or more flame stabilizing holes are provided on the frame wall of the flame port body. The flame stabilizing holes are rectangular strip holes. The areas of the flame stabilizing holes and the main flame holes are designed according to the requirements of stable combustion, and the area ratio of a single main flame hole to a single flame stabilizing hole is 1:0.3 - 1:0.4.

[0008] Furthermore, the burner nozzle body further includes a main burner hole surface, a bottom plane, and a reference plane; the bottom plane is 0.5-1 mm lower than the main burner hole surface; the main burner hole penetrates through the burner nozzle body, and the top of the main burner hole is flush with the main burner hole surface of the burner nozzle body; the bottom of the flame stabilizing burner hole is flush with the bottom plane of the burner nozzle body, so that the mixed air-fuel gas heats the root of the main burner hole after exiting the flame stabilizing burner hole, accelerating the combustion speed of the mixed air-fuel gas in the main burner hole and making the combustion of the main burner hole stable; the reference plane is connected to the frame wall; the bottom plane is lower than the main burner hole surface and the reference plane, thereby forming a groove.

[0009] Preferably, the width of the flame stabilizing burner hole is 0.1-0.3 mm, and the length is 1.2-2.0 mm, and its specific dimensions are adjusted according to the heat load and shape of the burner.

[0010] Preferably, the taper of the main burner hole is 1-1.5°, the height (the distance from the bottom plane to the main burner hole surface) is 0.35-0.5 mm, and the burner hole diameter is 0.5-0.8 mm, so as to ensure that the main burner hole has a speed of mixed air-fuel gas greater than that of the flame stabilizing burner hole.

[0011] Preferably, the height of the flame stabilizing burner hole is less than 1 / 2 of the height of the main burner hole to ensure the flame stabilizing effect of the flame stabilizing burner hole during combustion.

[0012] Preferably, the flame stabilizing burner hole and the main burner hole adopt small hole technology to reduce combustion noise.

[0013] Furthermore, the top view projection of the burner nozzle body is a rounded rectangle, and the size of the rounded rectangle can be adjusted according to the use requirements, and it can be a rounded square or a rounded rectangle.

[0014] Furthermore, the burner nozzle combination unit structure is applicable to blue flame combustion.

[0015] Furthermore, the flame of the flame stabilizing burner hole is a flame stabilizing flame; the flame of the main burner hole is a main flame.

[0016] Furthermore, the flame stabilizing methods of the flame stabilizing flame and the main flame are cross flame stabilization.

[0017] Furthermore, the total area of all the main burner holes and the total area of all the flame stabilizing burner holes are determined according to the power of the burner in use, and the greater the power, the greater the total area.

[0018] The second object of the present invention is to provide a fully premixed burner, which includes a plurality of the above-mentioned burner nozzle combination unit structures.

[0019] Furthermore, the fully premixed burner further includes a burner cavity.

[0020] Further, a premix burner including a plurality of the above-mentioned burner port combination unit structures determines the number of burner port combination unit structures according to the heat load of the burner, and the heat load of each burner port combination unit structure is 5-8.2 watts / mm 2 .

[0021] Preferably, the premix burner is a flat burner, a cylindrical burner or a circular well burner.

[0022] Further, the distance between adjacent burner port combination unit structures is not greater than 8 mm.

[0023] Preferably, the arrangement of a plurality of burner port combination unit structures is a matrix arrangement, a circular arrangement or a plum blossom arrangement.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1) The burner port combination unit structure provided by the present invention can prevent flashback when the premix burner operates under the condition that the air-fuel ratio is greater than 1.2, but the flame is about 1.5-3 away from the main burner port surface. In this way, even if the flame temperature decreases, it can avoid the high temperature of the burner port metal caused by the heat conduction of the flame temperature to the burner port metal material, resulting in surface discoloration or too fast flame propagation speed causing local flashback, thereby improving the stability of premix combustion.

[0026] 2) The burner port combination unit structure and the premix burner provided by the present invention can cover all premix burners that can apply the combustion principle, structural form, burner port layout and combination type used in the burner port combination unit structure, with wide application and strong practicability.

[0027] 3) In the burner port combination unit structure and the premix burner provided by the present invention, the flame stabilization method of the flame stabilization flame and the main flame is cross flame stabilization, which is different from the traditional parallel flame stabilization and can significantly improve the flame stabilization effect.

[0028] 4) In the burner port combination unit structure and the premix burner provided by the present invention, the flame stabilization burner ports and the main burner ports adopt small hole technology, which can significantly reduce the combustion noise.

[0029] 5) In the burner port combination unit structure and the premix burner provided by the present invention, the structure of the main burner port is a conical hole, which makes the main burner port have a certain burner port depth, can further evenly and stably the static pressure before the mixed air-fuel gas flows out, and makes the combustion of the main burner port stable without flame jitter phenomenon. Description of the Drawings

[0030] Figure 1 It is a top view schematic diagram of the burner port combination unit structure of Embodiment 1 in the present invention.

[0031] Figure 2Top view schematic diagram of the burner port combination unit structure of Embodiment 2 in the present invention.

[0032] Figure 3 Top view schematic diagram of the burner port combination unit structure of Embodiment 3 in the present invention.

[0033] Figure 4 Top view schematic diagram of the burner port combination unit structure of Embodiment 4 in the present invention.

[0034] Figure 5 Cross-sectional view schematic diagram of the burner port combination unit structure of Embodiment 1 in the present invention.

[0035] Figure 6 Top view schematic diagram of the fully premixed burner including the burner port combination unit structure arranged in a matrix in Embodiment 1 of the present invention.

[0036] Figure 7 Top view schematic diagram of the fully premixed burner including the burner port combination unit structure arranged in a circular pattern in Embodiment 1 of the present invention.

[0037] Wherein:

[0038] 1. Main flame, 2. Flame stabilizing flame, 3. Mixed air-fuel gas, 4. Flame stabilizing fire holes, 5. Main fire holes, 6. Main fire hole surface, 7. Bottom plane; 8. Reference plane, 9. Burner cavity. Detailed implementation manners

[0039] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, and other features not clearly described in this technical solution are regarded as common technical features disclosed in the prior art. In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0040] The content of the present invention will be further described in detail below with reference to specific embodiments.

[0041] Embodiment 1

[0042] As Figure 1As shown in the figure, a burner port combination unit structure includes a burner port body, and the burner port body includes a frame wall; a plurality of main burner ports 5 are provided on the burner port body; the main burner ports 5 are tapered holes to ensure the outlet speed of the mixed air-fuel gas 3; a plurality of flame stabilizing burner ports 4 are provided on the frame wall of the burner port body; the flame stabilizing burner ports 4 are rectangular strip holes; the areas of the flame stabilizing burner ports 4 and the main burner ports 5 are designed according to the requirements of stable combustion, and the area ratio of a single main burner port 5 to a single flame stabilizing burner port 4 is 1:0.3 - 1:0.4. The burner port body further includes a main burner port surface 6, a bottom plane 7 and a reference plane 8; the bottom plane 7 is 0.5 - 1 mm lower than the main burner port surface 6; the main burner ports 5 penetrate through the burner port body, and the tops of the main burner ports 5 are flush with the main burner port surface 6 of the burner port body; the bottoms of the flame stabilizing burner ports 4 are flush with the bottom plane 7 of the burner port body, so that the mixed air-fuel gas 3 heats the roots of the main burner ports 5 after flowing out of the flame stabilizing burner ports 4, accelerating the combustion speed of the mixed air-fuel gas 3 in the main burner ports 5 and making the combustion of the main burner ports 5 stable; the reference plane 8 is connected to the frame wall; the bottom plane 7 is lower than the main burner port surface 6 and the reference plane 8, thus forming a groove; the top view projection of the burner port body is a rounded rectangle.

[0043] As Figure 1 shown in the figure, among them, the top view projection of the burner port body is a rounded square, and there are three main burner ports 5, and the arrangement is triangular arrangement; there are four flame stabilizing burner ports 4, which are respectively distributed on each of the four frame walls.

[0044] As Figure 6 、 7 shown in the figure, a fully premixed burner includes the burner port combination unit structure of this embodiment.

[0045] Among them, Figure 6 、 7 are respectively fully premixed burners including burner port combination unit structures with different arrangement forms.

[0046] As Figure 6 shown in the figure, it is a top view schematic diagram of a fully premixed burner including the burner port combination unit structure of the first embodiment with a matrix arrangement in the present invention, and the distance between adjacent burner port combination unit structures is equal and not greater than 8 mm.

[0047] As Figure 7 shown in the figure, it is a top view schematic diagram of a fully premixed burner including the burner port combination unit structure of the first embodiment with a circular arrangement in the present invention, and the distance between adjacent burner port combination unit structures is not greater than 8 mm.

[0048] As Figure 1 、 Figure 5 、 Figure 6As shown in the figure, the structure of the burner port combination unit of this embodiment and the premix burner including the burner port combination unit structure arranged in a matrix are described in detail: the width of the stable flame port 4 is 0.1 mm, and the length is 2.0 mm; the taper of the main flame port 5 is 1°, and the height (the distance from the bottom plane 7 to the main flame port surface 6) is 0.5 mm, and the diameter of the main flame port 5 is 0.8 mm; the bottom plane 7 is 0.5 mm lower than the main flame port surface 6; the premix burner is a flat plate burner, and the premix burner further includes a burner cavity 9; the burner port combination unit structure in the premix burner is arranged in a 10×10 matrix, and the distance between adjacent burner port combination unit structures is 8 mm; the height of the stable flame port 4 is 0.2 mm. The working method and principle of the above premix burner are as follows:

[0049] 1) The gas enters the fan through the Venturi tube and is mixed to obtain the mixed air-fuel gas 3, and the mixed air-fuel gas 3 enters the burner cavity 9;

[0050] 2) Under a certain air pressure, the mixed air-fuel gas 3 flows out through the main flame port 5 and the stable flame port 4 at a certain speed respectively, generating the main flame 1 and the stable flame 2 respectively;

[0051] 3) The flow velocity of the stable flame 2 is lower than that of the main flame 1, and the flow velocity of the mixed air-fuel gas 3 flowing out of the outlet of the main flame port 5 is 2-3 times higher than that of the mixed air-fuel gas 3 flowing out of the outlet of the stable flame port 4;

[0052] 4) After the stable flame 2 flows out of the stable flame port 4, part of the stable flame 2 heats the root of the nearest main flame port 5, and a part of the flame rises along the main flame port 5 to continue heating the main flame 1; another part of the stable flame 2 continues to spread to heat the other main flame ports 5 except the nearest main flame port 5; the four stable flames 2 converge within the burner port combination unit structure to form a stable temperature heating layer in the groove of the burner port combination unit structure to heat the root of the main flame 1;

[0053] 5) With the heating of the stable flame 2, the main flame 1 extends and spreads, the ignition point of the main flame 1 is advanced, the main flame 1 is ignited and burned at the position 1.5-3 mm away from the main flame port 5, and because there is a stable temperature heating layer at the root of the main flame 1, the flame height of each main flame 1 during combustion is consistent;

[0054] 6) Within each burner port combination unit structure, the height of the main flame 1 is consistent, forming the entire flame group composed of multiple burner port combination unit structures of the entire premix burner. The height and temperature of the main flame 1 in the flame group are consistent, which is convenient for controlling the combustion temperature and the generation conditions of nitrogen oxides.

[0055] Since the main flame 1 of the above full-premix burner burns 1.5 - 3 mm after leaving the main flame hole 5, the main flame hole 5 is cooled by the mixed air-fuel gas 3, which can reduce the temperature of the burner surface and ensure the reliability of the burner operation; since the flame-stabilizing mode of the flame-stabilizing flame 2 and the main flame 1 is cross flame stabilization, which is different from the traditional parallel flame stabilization, the flame-stabilizing effect is significantly improved; since the flame-stabilizing flame holes 4 and the main flame holes 5 adopt small-hole technology, the combustion noise is significantly reduced; since the main flame hole 5 of the main flame 1 is a conical hole, the main flame hole 5 has a certain flame hole depth, which makes the static pressure of the mixed air-fuel gas 3 more uniform and stable before flowing out, making the main flame 1 burn stably without flame jitter phenomenon.

[0056] Embodiment 2

[0057] As Figure 2 shown, a flame hole combination unit structure, wherein, the top view projection of the flame hole body is a rounded square, provided with four main flame holes 5, and the arrangement mode is matrix arrangement; provided with four flame-stabilizing flame holes 4, which are respectively distributed on each of the four side wall surfaces.

[0058] Embodiment 3

[0059] As Figure 3 shown, a flame hole combination unit structure, wherein, the top view projection of the flame hole body is a rounded rectangle, provided with nine main flame holes 5, three in a group, and the arrangement mode of each group is triangular arrangement; provided with eight flame-stabilizing flame holes 4, which are respectively distributed on each of the four side wall surfaces.

[0060] Embodiment 4

[0061] As Figure 4 shown, a flame hole combination unit structure, wherein, the top view projection of the flame hole body is a rounded rectangle, provided with twelve main flame holes 5, four in a group, and the arrangement mode of each group is matrix arrangement; provided with eight flame-stabilizing flame holes 4, which are respectively distributed on each of the four side wall surfaces.

[0062] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. Those skilled in the art can obviously make various modifications to these embodiments easily and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A structure of a burner combination unit, characterized in that, It includes a burner port body, and the burner port body includes a frame wall; One or more main burner holes (5) are provided on the burner port body; The main burner holes (5) are tapered holes; One or more flame stabilizing holes (4) are provided on the frame wall of the burner port body; The flame stabilizing holes (4) are rectangular strip holes; The area ratio of a single main burner hole (5) to a single flame stabilizing hole (4) is 1:0.3 - 1:0.4; The burner port body further includes a main burner hole surface (6), a bottom plane (7) and a reference plane (8); The bottom plane (7) is 0.5 - 1 mm lower than the main burner hole surface (6); The main burner holes (5) penetrate through the burner port body, and the tops of the main burner holes (5) are flush with the main burner hole surface (6) of the burner port body; The bottoms of the flame stabilizing holes (4) are flush with the bottom plane (7) of the burner port body; The reference plane (8) is connected to the frame wall; The bottom plane (7) is lower than the main burner hole surface (6) and the reference plane (8), thereby forming a groove; The width of the flame stabilizing holes (4) is 0.1 - 0.3 mm, and the length is 1.2 - 2.0 mm; The taper of the main burner holes (5) is 1 - 1.5°, the height is 0.5 - 1 mm, and the burner hole diameter is 0.5 - 0.8 mm.

2. The structure of a tuyere combination unit according to claim 1, characterized in that, The height of the flame stabilizing holes (4) is less than 1 / 2 of the height of the main burner holes (5).

3. The structure of a tuyere combination unit according to claim 1, characterized in that, The top view projection of the burner port body is a rounded rectangle.

4. A fully premixed burner, characterized in that, It includes a plurality of burner port combination unit structures as described in any one of claims 1 - 3.

5. The all-premixed burner according to claim 4, characterized in that, The fully premixed burner is a flat burner, a cylindrical burner or a circular well - type burner.

6. The all-premix burner according to claim 4, wherein The distance between adjacent burner port combination unit structures is not greater than 8 mm.

7. The all-premixed burner according to claim 4, characterized in that, The arrangement mode of the plurality of burner port combination unit structures is matrix arrangement, circular arrangement or plum - blossom arrangement.

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