A high-turndown-ratio modular low-nitrogen burner and combustion adjustment method

Abstract

The present invention provides a high-regulation ratio modular low-nitrogen burner and a combustion regulation method. The burner includes a plurality of spliced ​​burner modules, and the burner module includes a flame disk, a nozzle, a side air plate, an air duct side plate, an upper gas pipeline and a lower gas pipeline. When operating at a relatively low power, the upper gas pipeline supplies gas, and the gas is mixed with the combustion-supporting air flowing out of the flame disk and burned. The combustion-supporting air coming out of the side air plate continuously blows toward the flame to cool the flame, thereby achieving the effect of reducing the nitrogen oxide content in the flue gas. When operating at a high power, the upper gas pipeline and the lower gas pipeline supply gas at the same time, and the lower gas and air are premixed in the air duct in advance. The combustion flame is uniform and there is no local high temperature, which effectively reduces the nitrogen oxide content in the combustion flue gas. It can not only ensure a large regulation ratio during the operation of the burner, but also significantly reduce the nitrogen oxide content in the combustion flue gas to meet increasingly stringent emission requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of burners, and in particular to a high-regulation-ratio modular low-nitrogen burner and a combustion regulation method. Background Art

[0002] With the development of society and the improvement of science and technology, the requirements for environmental protection are getting higher and higher, and the requirements for exhaust emissions from industrial burners are becoming more and more stringent. At present, the emission indicators for nitrogen oxides have been greatly reduced. In this case, traditional burners are not suitable for applications under new requirements and new standards. Traditional burners are generally divided into two types, one is nozzle mixing type and the other is premixing type. The two types of burners have their own advantages and disadvantages. The nozzle mixing burner has a large adjustment ratio and can meet the production needs under different working conditions. However, the content of nitrogen oxides in the combustion emissions of this type of burner is relatively high, which is difficult to meet today's increasingly stringent emission requirements; while the nitrogen oxide emissions of premixing burners are relatively low and can meet emission requirements, but the disadvantage of this burner is that it is easy to cause backfire after premixing and the adjustment ratio is relatively small, which makes it relatively passive in industrial applications. Summary of the Invention

[0003] In order to overcome the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a high-turndown-ratio modular low-nitrogen burner and a combustion adjustment method.

[0004] To achieve the above-mentioned purpose, the present invention solves the technical problem by adopting the following technical solution: a modular low-nitrogen burner with a high turndown ratio, comprising a plurality of burner modules connected together, wherein the burner module comprises a flame disk, a nozzle, a side air plate, an air duct side plate, an upper gas pipeline and a lower gas pipeline,

[0005] The air duct side panels are combined to form a combustion-supporting air main air duct for providing combustion-supporting gas;

[0006] The flame disc is arranged in the middle of the outlet of the combustion air main duct, and a first outlet is provided on the flame disc;

[0007] The side air plates are provided on both sides of the flame disk, the side air plates extend from the flame disk in the air outlet direction, and the side air plates are provided with a second air outlet;

[0008] The nozzle is arranged in the middle of the flame disk, and the fuel outlet of the nozzle is located on the air outlet side of the flame disk;

[0009] The upper gas pipeline and the lower gas pipeline are used to provide gas fuel;

[0010] The upper gas pipeline is extended along the connecting direction of each nozzle, and each nozzle is connected to the upper gas pipeline, and further includes a first control valve for regulating the gas supply flow in the upper gas pipeline;

[0011] The lower-layer gas pipeline is arranged in the main air duct of the combustion-supporting air. The lower-layer gas pipeline extends along a plane perpendicular to the air outlet direction in the main air duct of the combustion-supporting air. The lower-layer gas pipeline is provided with multiple fuel outlets and also includes a second control valve for regulating the gas supply flow in the lower-layer gas pipeline.

[0012] By adopting the technical solution of the present invention, the overall structure of the burner adopts a modular design and can be flexibly assembled according to the application and power requirements. The upper gas pipeline and the lower gas pipeline are used to provide gas respectively. When the burner is running at a lower power, the second control valve is closed and only the first control valve is opened. In this way, the gas enters the nozzle through the upper gas pipeline. The gas ejected from the nozzle is mixed with the combustion-supporting air flowing out of the flame disk and burns. The combustion-supporting air coming out of the side wind plate continuously blows towards the flame, cooling the flame and reducing the temperature around the flame, thereby achieving the effect of reducing the nitrogen oxide content in the flue gas. The combustion mode at this time belongs to nozzle mixing combustion. When burning at a low fire, there is no problem of backfire. The burner can operate relatively stably at a lower power. When the burner is operating at high power, both the first and second control valves are open. Gas in the upper gas pipeline is ejected through the nozzle and mixed with the combustion air flowing out of the flame disk to produce a flame. Meanwhile, gas in the lower gas pipeline is ejected and mixed evenly with the combustion air in the main combustion air duct. A portion of the gas flows out of the flame disk and ignites, while the remaining portion flows out through the side air plates and ignites. Because the gas and air are premixed in the air duct, the combustion flame is uniform and there is no local high temperature, effectively reducing the nitrogen oxide content in the combustion flue gas. At the same time, due to the high operating power and relatively large combustion air volume at this time, the combustion air flow rate is relatively high, exceeding the flame propagation speed of the gas. Therefore, flashback does not occur at this time, ensuring safe operation. This ensures a large turndown ratio during burner operation and significantly reduces the nitrogen oxide content in the combustion flue gas, meeting increasingly stringent emission requirements.

[0013] Furthermore, the flame disk is provided with a plurality of first air outlets distributed in a circumference, and an oblique guide plate is provided on the air outlet side of the first air outlet, and the inclination angle between the oblique guide plate and the flame disk is 30°-45°.

[0014] By adopting the above preferred solution, a swirl effect is formed by the oblique guide vanes, which strengthens the mixing with the gas ejected from the nozzle, making the burner flame shorter, the heat radiation more uniform, and the nitrogen oxide emissions significantly reduced.

[0015] Furthermore, the side wind plates are extended outward from the root in an outwardly expanding state, and the angle between the side wind plates and the vertical direction is 10°-15°.

[0016] Furthermore, the second air outlet on the side air plate is in a strip shape, and the second air outlet is extended from the root to the top of the side air plate.

[0017] By adopting the above preferred solution and the reasonable side air plate outlet design, it can not only take into account the effect of cooling the flame temperature at low power, but also ensure the flame stability at high power.

[0018] Furthermore, the ratio of the vertical depth of the side air plate to the width of the flame disk is 1.0-1.5, the vertical depth of the side air plate is not greater than 210 mm, and the width of the flame disk is not greater than 150 mm.

[0019] The above preferred solution is adopted to ensure the provision of stable side wind pressure and reduce the requirements on the air supply capacity of the fan.

[0020] Furthermore, the top end of the nozzle is closed, the nozzle has multiple fuel outlets, and the fuel outlets of the nozzle are oriented toward the circumference of the nozzle.

[0021] The above preferred solution is adopted to promote the full mixing of fuel and the surrounding swirl wind, and to achieve uniform combustion.

[0022] Furthermore, the fuel outlets on the lower gas pipeline are arranged on both sides of the lower gas pipeline body, and the fuel outlets on the lower gas pipeline face the side plates of the air duct.

[0023] Furthermore, the distance between the upper gas pipeline and the lower gas pipeline is 200-300 mm.

[0024] By adopting the above preferred solution, the gas ejection direction of the lower gas pipeline is perpendicular to the wind direction of the combustion-supporting air main duct, and the reasonable spacing between the upper and lower gas pipelines ensures the premixing effect.

[0025] Furthermore, it also includes an upper air uniforming mesh plate and a lower air uniforming mesh plate, the upper air uniforming mesh plate is arranged below the upper gas pipeline, and the lower air uniforming mesh plate is arranged below the lower gas pipeline.

[0026] By adopting the above preferred solution, the air volume in the air duct is adjusted uniformly by the upper and lower air uniforming mesh plates.

[0027] A combustion adjustment method, using the above-mentioned high adjustment ratio modular low-nitrogen burner, comprises:

[0028] In low power mode, the second control valve is closed, the first control valve is opened and regulates the gas supply to the upper gas pipeline;

[0029] In the high power mode, the first control valve opens and adjusts the gas supply in the upper gas pipeline, and the second control valve opens and adjusts the gas supply in the lower gas pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 It is a structural schematic diagram of an embodiment of a burner of the present invention;

[0032] Figure 2 yes Figure 1 A partial enlarged view of point C in the middle;

[0033] Figure 3 This is one of the cross-sectional structural diagrams of the burner of the present invention;

[0034] Figure 4 This is the second cross-sectional structural diagram of the burner of the present invention;

[0035] Figure 5 This is a schematic diagram of the principle of the low-power combustion state of the present invention;

[0036] Figure 6 It is a schematic diagram of the high-power combustion state principle of the present invention.

[0037] The numbers and letters in the figure represent the names of the corresponding parts:

[0038] 1-flame disk; 101-first air outlet; 102-oblique guide vane; 2-nozzle; 201-fuel outlet; 3-side air plate; 301-second air outlet; 4-upper gas pipeline; 5-lower gas pipeline; 501-fuel outlet; 6-upper uniform air mesh plate; 7-lower uniform air mesh plate; 8-air duct side panel; 801-combustion air main duct. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] like Figure 1-6 As shown, one embodiment of the present invention is: a high turndown ratio modular low-nitrogen burner, comprising a plurality of burner modules spliced ​​together, wherein the burner module comprises a flame disk 1, a nozzle 2, a side air plate 3, an air duct side plate 8, an upper gas pipeline 4 and a lower gas pipeline 5,

[0041] The air duct side panels 8 are combined to form a combustion air main duct 801 for providing combustion-supporting gas;

[0042] The flame disc 1 is arranged in the middle of the outlet of the combustion air main duct 801, and a first outlet 101 is provided on the flame disc 1;

[0043] The side air plates 3 are provided on both sides of the flame disc 1. The side air plates 3 extend from the flame disc 1 in the air outlet direction. The side air plates 3 are provided with a second air outlet 301.

[0044] The nozzle 2 is arranged in the middle of the flame disk 1, and the fuel outlet 201 of the nozzle 2 is located on the air outlet side of the flame disk 1;

[0045] The upper gas pipeline 4 and the lower gas pipeline 5 are used to provide gas fuel;

[0046] The upper gas pipeline 4 is extended along the connecting direction of each nozzle 2, and each nozzle 2 is connected to the upper gas pipeline 4, and further includes a first control valve for regulating the gas flow in the upper gas pipeline 4;

[0047] The lower-level gas pipeline 5 is arranged in the main combustion-supporting air duct 801. The lower-level gas pipeline 5 extends along a plane perpendicular to the air outlet direction in the main combustion-supporting air duct 801. The lower-level gas pipeline 5 is provided with multiple fuel outlets 501 and also includes a second control valve for regulating the gas supply flow in the lower-level gas pipeline 5.

[0048] The beneficial effect of adopting the above technical solution is that the overall structure of the burner adopts modular design and can be flexibly assembled according to the application and power requirements. The upper gas pipeline and the lower gas pipeline are used to provide gas respectively. Figure 5 When the burner is running at a lower power, the second control valve is closed and only the first control valve is opened. In this way, the gas enters the nozzle through the upper gas pipeline, and the gas ejected from the nozzle is mixed with the combustion-supporting air flowing out of the flame disk for combustion. The combustion-supporting air coming out of the side air plate continuously blows towards the flame, cooling the flame and reducing the temperature around the flame, thereby achieving the effect of reducing the nitrogen oxide content in the flue gas. The combustion mode at this time belongs to nozzle mixing combustion. When burning at a low fire, there is no problem of backfire, and the burner can operate relatively stably at a lower power. Figure 6When the burner is operating at high power, both the first and second control valves are open. Gas in the upper gas pipeline is ejected through the nozzle and mixed with the combustion air flowing out of the flame disk to produce a flame. Meanwhile, gas in the lower gas pipeline is ejected and evenly mixed with the combustion air in the main combustion air duct. A portion of the gas flows out of the flame disk and ignites, while the remaining portion flows out through the side air vanes and ignites. Because the gas and air are premixed in the air duct, the combustion flame is uniform and there are no localized high temperatures, effectively reducing the nitrogen oxide content in the combustion flue gas. Furthermore, due to the high operating power and relatively large combustion air volume, the combustion air flow rate is relatively high, exceeding the flame propagation speed of the gas. Therefore, flashback is prevented, ensuring safe operation. This ensures a large turndown ratio during burner operation and significantly reduces the nitrogen oxide content in the combustion flue gas, meeting increasingly stringent emission requirements.

[0049] like Figure 2 As shown, in other embodiments of the present invention, the flame disk 1 is provided with a plurality of first air outlets 101 distributed circumferentially. Diagonal guide vanes 102 are provided on the outlet side of the first air outlets 101. The angle between the diagonal guide vanes 102 and the flame disk is between 30° and 45°. The diagonal guide vanes 102 create a swirl effect, enhancing mixing with the gas ejected from the nozzle. This results in a shorter burner flame, more uniform heat radiation, and significantly reduced nitrogen oxide emissions.

[0050] like Figure 2 、 4 As shown, in other embodiments of the present invention, the side air panels 3 extend outward from the base, forming an angle α of 10°-15° with the vertical. The second air outlet on the side air panel is in the form of an elongated strip, extending from the base to the top. The beneficial effect of this technical solution is that a reasonable side air panel outlet design can achieve both flame temperature cooling at low power and flame stability at high power.

[0051] like Figure 4 As shown, in other embodiments of the present invention, the ratio of the vertical depth h of the side air plate 3 to the width d of the flame disk is 1.0-1.5, the vertical depth of the side air plate h is no greater than 210 mm, and the width of the flame disk d is no greater than 150 mm. The beneficial effect of adopting the above technical solution is to ensure stable side wind pressure and reduce the air supply capacity requirements of the fan.

[0052] like Figure 2 、 3As shown, in other embodiments of the present invention, the top of the nozzle 2 is closed, and the nozzle has multiple fuel outlets 201, which are oriented toward the circumference of the nozzle. The beneficial effect of adopting the above technical solution is to promote the full mixing of fuel and the surrounding swirling wind, and even combustion.

[0053] like Figure 3 As shown, in other embodiments of the present invention, fuel outlets 501 on the lower gas pipeline 5 are located on both sides of the lower gas pipeline 5, facing the air duct side panels 8. The distance between the upper gas pipeline 4 and the lower gas pipeline 5 is 200-300 mm. The beneficial effects of this technical solution include: the gas ejection direction of the lower gas pipeline is perpendicular to the wind direction of the main combustion air duct, and the reasonable spacing between the upper and lower gas pipelines ensures a good premixing effect.

[0054] In other embodiments of the present invention, an upper air uniforming mesh plate 6 and a lower air uniforming mesh plate 7 are further included. The upper air uniforming mesh plate 6 is disposed below the upper gas pipeline 4, and the lower air uniforming mesh plate 7 is disposed below the lower gas pipeline 5. The beneficial effect of the above technical solution is that the air volume in the air duct is uniformly adjusted by the upper and lower air uniforming mesh plates.

[0055] In other embodiments of the present invention, the lower layer of uniform air mesh includes a first mesh and a second mesh arranged in an interlaced manner, and also includes a driving mechanism that drives the first mesh and the second mesh relative to each other. When the first mesh and the second mesh are in a first relative position state, the porosity of the lower layer of uniform air mesh is a; when the first mesh and the second mesh are in a second relative position state, the porosity of the lower layer of uniform air mesh is b, and a is greater than b. When the burner is in low power mode, the driving mechanism drives the first mesh and the second mesh to be in a first relative position state, reducing the wind resistance of the lower layer of uniform air mesh and saving fan power consumption; when the burner is in high power mode, the driving mechanism drives the first mesh and the second mesh to be in a second relative position state, improving the uniform air capability and improving the premixing effect.

[0056] A combustion adjustment method, comprising:

[0057] In low power mode, the second control valve is closed, the first control valve is opened and regulates the gas supply to the upper gas pipeline;

[0058] In the high power mode, the first control valve opens and adjusts the gas supply in the upper gas pipeline, and the second control valve opens and adjusts the gas supply in the lower gas pipeline.

[0059] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable ordinary technicians in this field to understand the content of the present invention and implement it. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A modular low-nitrogen burner with a high turndown ratio, characterized in that: It includes multiple burner modules connected together, each of which includes a flame disk, a nozzle, a side air plate, an air duct side plate, an upper gas pipeline and a lower gas pipeline. The air duct side panels are combined to form a combustion-supporting air main air duct for providing combustion-supporting gas; The flame disc is arranged in the middle of the outlet of the combustion air main duct, and a first outlet is provided on the flame disc; The side air plates are provided on both sides of the flame disk, the side air plates extend from the flame disk in the air outlet direction, and the side air plates are provided with a second air outlet; The nozzle is arranged in the middle of the flame disk, and the fuel outlet of the nozzle is located on the air outlet side of the flame disk; The upper gas pipeline and the lower gas pipeline are used to provide gas fuel; The upper gas pipeline is extended along the connecting direction of each nozzle, and each nozzle is connected to the upper gas pipeline, and further includes a first control valve for regulating the gas supply flow in the upper gas pipeline; The lower gas pipeline is arranged in the combustion-supporting air main duct, and the lower gas pipeline extends along a plane perpendicular to the air outlet direction in the combustion-supporting air main duct. The lower gas pipeline is provided with a plurality of fuel outlets, and further includes a second control valve for regulating the gas supply flow in the lower gas pipeline; The flame disk is provided with a plurality of first air outlets distributed in a circumference, and an oblique guide plate is provided on the air outlet side of the first air outlet, and the inclination angle between the oblique guide plate and the flame disk is 30°-45°; The side wind plates extend outward from the base in an outwardly expanding state, and the angle between the side wind plates and the vertical direction is 10°-15°; The second air outlet on the side air plate is in the shape of an elongated strip, and the second air outlet is extended from the base to the top of the side air plate; The ratio of the vertical depth of the side air plate to the width of the flame disk is 1.0-1.5, the vertical depth of the side air plate is not greater than 210 mm, and the width of the flame disk is not greater than 150 mm; The top end of the nozzle is closed, the nozzle has multiple fuel outlets, and the fuel outlets of the nozzle are oriented toward the circumference of the nozzle; The fuel outlets on the lower gas pipeline are arranged on both sides of the lower gas pipeline body, and the fuel outlets on the lower gas pipeline face the side panels of the air duct; The distance between the upper gas pipeline and the lower gas pipeline is 200-300mm; The combustion-supporting air in the combustion-supporting air main air duct flows out from the first air outlet and the second air outlet.

2. The high turndown ratio modular low nitrogen burner according to claim 1 is characterized in that: It also includes an upper air uniforming mesh plate and a lower air uniforming mesh plate. The upper air uniforming mesh plate is arranged below the upper gas pipeline, and the lower air uniforming mesh plate is arranged below the lower gas pipeline.

3. A combustion adjustment method, using the high adjustment ratio modular low nitrogen burner according to any one of claims 1-2, characterized in that: include: In low power mode, the second control valve is closed, the first control valve is opened and regulates the gas supply to the upper gas pipeline; In the high power mode, the first control valve opens and adjusts the gas supply in the upper gas pipeline, and the second control valve opens and adjusts the gas supply in the lower gas pipeline.

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