Air cooling structure of rich-lean combustion low-nitrogen combustor and rich-lean combustion low-nitrogen combustor

Abstract

The utility model relates to an air cooling structure of a rich-lean combustion low-nitrogen combustor and the rich-lean combustion low-nitrogen combustor. The air cooling structure comprises a heat insulation plate (1), a left side plate (2) and a right side plate (3). The heat insulation plate (1) is arranged on the upper side of a combustor and embedded into a gap between fire rows of the combustor, the left side plate (2) and the right side plate (3) are arranged on the left side and the right side of the combustor respectively, air holes (4) are formed in the left side plate (2) and the right side plate (3), and a fuel gas injection opening of the fire rows is formed between the left side plate (2) and the right side plate (3). Compared with the prior art, through heat insulation and air cooling, the surface temperature rise of the fire grate is effectively reduced, the temperature of the combustion chamber is reduced, the nitrogen oxide generation condition is inhibited, and the emission value is reduced.

Description

Technical Field

[0001] This utility model relates to the field of burner technology, and in particular to an air-cooled structure and a rich-lean combustion low-NOx burner. Background Technology

[0002] Rich-lean combustion low-NOx burners are a new type of low-NOx burner with advantages such as low cost and simple installation. Rich-lean low-NOx burners do not require secondary air for combustion, so a baffle plate is typically used at the bottom of the burner to prevent the entry of secondary air. However, during operation, the rich flame is low, almost close to the burner nozzle, and the flame temperature is relatively high. This results in very intense radiation and heat conduction to the burner grate. The gas-air mixture flowing within the grate provides minimal cooling, insufficient to remove such a large amount of heat. After a period of operation, the surface temperature of the burner grate becomes high, further increasing the temperature of the gas-air mixture inside. This increased temperature accelerates combustion, raises the flame temperature, and leads to increased formation of nitrogen oxides (NOx). Therefore, NOx emissions increase after the burner has been operating for a period of time. Utility Model Content

[0003] The purpose of this invention is to provide an air-cooled structure and a rich-lean combustion low-NOx burner to reduce nitrogen oxide emissions.

[0004] The purpose of this utility model can be achieved through the following technical solution: an air-cooled structure for a rich-lean combustion low-NOx burner, including a heat insulation plate, a left side plate and a right side plate;

[0005] The heat insulation plate is set on the upper side of the burner and embedded in the gap between the burner's burners. The left and right side plates are respectively set on the left and right sides of the burner. The left and right side plates are provided with air holes. The gas injection port of the burner is set between the left and right side plates.

[0006] Preferably, the heat insulation plate is a stainless steel plate.

[0007] Preferably, the heat insulation plate has an opening of the same size as the flame nozzle of the fire bar.

[0008] Preferably, the air vent is located between two adjacent fire bars.

[0009] Preferably, the height of the air hole is 35-50 mm.

[0010] Preferably, the gas injection port of the fire bar includes a rich gas injection port and a lean gas injection port.

[0011] More preferably, the diameter of the rich gas injection port is smaller than that of the desalinated gas injection port.

[0012] More preferably, the rich gas injection port is located above the light gas injection port and communicates with the rich gas injection port.

[0013] More preferably, the fresh gas injection port is connected to the fresh gas burner port.

[0014] A rich-lean combustion low-NOx burner, comprising the aforementioned air-cooled structure.

[0015] Preferably, the burner further includes a burner baffle, a front baffle, a rear baffle, and an air deflector;

[0016] Multiple burners are arranged in parallel and spaced apart within a frame structure formed by a left side plate, a right side plate, a front baffle, a rear baffle, and an air guide plate, with a gas inlet provided on the air guide plate.

[0017] More preferably, the gas inlet is connected to a gas outlet located within the frame structure and corresponding to the gas ejector port of each burner.

[0018] More preferably, the air deflector has a gas inlet at the bottom center, and the bottom center of the air deflector protrudes downward.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. By setting air holes on the left and right side plates, the present invention allows air to cool the surface of the burner before entering the gas injection port. By using air flow to cool the burner burner, the surface temperature of the burner burner can be reduced, the conditions for nitrogen oxide formation can be suppressed, and the nitrogen oxide emission value can be reduced.

[0021] 2. By setting up a heat insulation plate, this utility model can prevent the burner from radiating to the burner grate during operation by heat insulation method on the burner combustion plane, thereby reducing the surface temperature of the burner grate, suppressing the conditions for nitrogen oxide formation, and reducing nitrogen oxide emission values.

[0022] 3. This utility model effectively reduces the surface temperature rise of the burner and the combustion chamber temperature by heat insulation and air cooling, thereby suppressing the formation of nitrogen oxides and reducing emissions.

[0023] 4. This utility model has a simple structure, low cost, and is energy-saving and environmentally friendly. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the structure and working principle of the air-cooled structure of this utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the heat insulation board of this utility model;

[0026] Figure 3 This is a top view of the rich-lean combustion low-NOx burner of this utility model;

[0027] Figure 4 This is a left view of the rich-lean combustion low-NOx burner of this utility model;

[0028] Figure 5 This is a right view of the rich-lean combustion low-NOx burner of this utility model;

[0029] In the diagram: 1-Insulation plate, 2-Left side plate, 3-Right side plate, 4-Air hole, 5-Rich gas injector, 6-Lean gas injector, 7-Flame rack, 8-Front baffle, 9-Rear baffle, 10-Air guide plate, 11-Gas inlet, 12-Gas outlet, 13-Fixed component. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. This embodiment is based on the technical solution of the present invention and provides detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] Example 1

[0034] An air-cooled structure for a rich-lean combustion low-NOx burner, such as Figure 1 As shown, it includes a heat insulation panel 1, a left side panel 2, a right side panel 3, and an air hole 4.

[0035] The heat insulation plate 1 is located on the upper side of the burner, the left side plate 2 is located on the left side of the burner, and the right side plate 3 is located on the right side of the burner. The heat insulation plate 1 is embedded in the gap between the burner's burners to block the flame from radiating to the burner's burners. The air hole 4 is located on the left side plate 2 and the right side plate 3. The gas injection port of the burner's burners is located between the left side plate 2 and the right side plate 3.

[0036] The working principle of the air-cooled structure in this embodiment is as follows: air enters the burner through the air holes 4 of the left side plate 2 and the right side plate 3, and when it flows through the burner grate, it reduces the temperature of the burner grate and carries the heat of the grate into the gas injection port of the grate.

[0037] Example 2

[0038] A wind-cooled structure for a rich-lean combustion low-NOx burner includes a stainless steel heat insulation plate 1 with openings of the same size as the flame nozzle of the burner. Multiple air holes are spaced apart on both the left side plate 2 and the right side plate 3, with each air hole located between two adjacent burners and having a height of 35-50 mm. The rest is the same as in Example 1.

[0039] Example 3

[0040] A rich-lean combustion low-NOx burner, comprising the air-cooled structure described in Example 2, such as... Figures 3-5 As shown, it also includes a burner 7, a front baffle 8, a rear baffle 9, an air deflector 10, and a gas inlet 11.

[0041] Specifically, the left side plate 2, right side plate 3, front baffle 8, rear baffle 9 and air guide plate 10 enclose a frame structure, and multiple burners 7 are arranged in a matrix of two columns and multiple rows within the frame structure. The length direction of each burner 7 is set along the left and right direction, and the gas injection port is set within the frame structure and faces the center.

[0042] Furthermore, in this embodiment, the gas injection port includes a rich gas injection port 5 that is connected to the rich gas injection port and a light gas injection port 6 that is connected to the light gas injection port. The diameter of the rich gas injection port 5 is smaller than that of the light gas injection port 6 and it is located above the light gas injection port 6.

[0043] The air deflector 10 has a gas inlet 11 at the bottom center, which is connected to the gas outlet 12 located in the frame structure. Gas enters through the gas inlet 11 and is ejected through the gas outlet 12. It is drawn in together with the air entering through the air hole 4 by the rich gas injector 5 and the lean gas injector 6. Because the diameter of the rich gas injector 5 is relatively small, most of the air is drawn in through the lean gas injector 6, mixed with the gas, and flows out through the lean burner. A small portion of the air is drawn in through the rich gas injector 5, mixed with the gas, and flows out through the rich burner.

[0044] Example 4

[0045] An air-cooled structure for a rich-lean combustion low-NOx burner includes a heat insulation plate 1 above the burner to block the radiation of the combustion flame. Air enters the burner through air inlets (air holes 4) on the left side plate 2 and the right side plate 3. After cooling the burner burner grate, air enters the burner injector. Because the heat radiation of the flame is blocked, the surface temperature of the burner is reduced, and the heat conducted from the flame to the burner grate is carried into the injector by the air entering the burner.

[0046] Specifically, the heat insulation panel 1 is made of two thin stainless steel sheets. For example... Figure 2As shown, the openings A, B, C, D, and E on the heat insulation plate 1 are the same size as those at the burner flame nozzle. For a tighter seal, the clearance should be as small as possible. The heat insulation plate 1 is fixed to the end faces of the front, rear, left, and right plates of the burner using screws (fixture 13). The heat insulation plate 1 is embedded in the gap between the burner flame bars, thus blocking the flame radiation to the burner flame bars.

[0047] The left side plate 2 and the right side plate 3 have several rectangular holes (air holes 4) located between the two burners. The width of the holes is determined by the spacing between the burners, and the width should be as large as possible without affecting the stability of the burners. The height of the holes is controlled between 35-50mm to ensure that the required amount of air for the combustion gas enters the burner through these holes.

[0048] In this embodiment, the excess air coefficient is around 1.2-1.4.

[0049] At the bottom of the burner is the air deflector 10. The air deflector 10 seals the bottom of the burner, allowing airflow to follow its structure. The downward protrusion of its middle section is controlled at 20-30mm. Too large a protrusion would occupy too much space and affect the overall structural arrangement; too small a protrusion would result in excessive air resistance and high flow velocity, affecting nozzle ejection. The deflector is fixed to the burner bracket with screws.

[0050] Comparative Example 1

[0051] A conventional rich-lean combustion low-NOx burner exhibits excellent low-NOx performance during the initial 2-3 hours of operation. However, with prolonged continuous operation, NOx emissions show a slight increase, for example, initially showing a decrease in NOx emissions to [missing value]. x The initial concentration was 5 ppm, which rose to 8 ppm after 3 hours. Measurements of the burner burner surface temperature after 5 hours of operation showed a peak of approximately 350°C. This high surface temperature heated the gas mixture inside the burner, bringing the temperature of the gas mixture close to 80°C.

[0052] The increased temperature of the air-fuel mixture accelerates combustion, raises flame temperature, and leads to increased formation of nitrogen oxides (NOx). This is the main reason for the increased NOx emissions after a period of operation. Measurements after 5 hours of operation showed: oxygen content 11.5-14%; NOx 8-10 ppm.

[0053] After the air-cooling structure of this utility model is improved, under the same conditions, the oxygen content is 11-12% and the nitrogen oxides are less than 7ppm.

[0054] This invention employs an air-cooled structural design to cool the burner grate surface before air enters the burner injection port. Furthermore, heat insulation is used on the burner combustion plane to prevent radiation to the grate during burner operation. This combination of heat insulation and air cooling effectively reduces the grate surface temperature rise, lowers the combustion chamber temperature, suppresses nitrogen oxide formation conditions, and reduces emissions.

[0055] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. An air-cooled structure for a rich-lean combustion low-NOx burner, characterized in that, It includes a heat insulation panel (1), a left side panel (2), and a right side panel (3); The heat insulation plate (1) is set on the upper side of the burner and embedded in the gap between the burner's burners. The left side plate (2) and the right side plate (3) are respectively set on the left and right sides of the burner. The left side plate (2) and the right side plate (3) are provided with air holes (4). The gas injection port of the burner is set between the left side plate (2) and the right side plate (3).

2. The air-cooled structure of the rich-lean combustion low-NOx burner according to claim 1, characterized in that, The heat insulation plate (1) is a stainless steel plate, and the heat insulation plate (1) has openings of the same size as the flame opening of the fire bar.

3. The air-cooled structure of the rich-lean combustion low-NOx burner according to claim 1, characterized in that, The air hole (4) is located between two adjacent fire bars.

4. The air-cooled structure of the rich-lean combustion low-NOx burner according to claim 1, characterized in that, The height of the air hole (4) is 35-50mm.

5. The air-cooled structure of the rich-lean combustion low-NOx burner according to claim 1, characterized in that, The gas injection port of the fire briquette includes a rich gas injection port (5) and a lean gas injection port (6); The diameter of the rich gas injection port (5) is smaller than that of the light gas injection port (6).

6. The air-cooled structure of the rich-lean combustion low-NOx burner according to claim 5, characterized in that, The rich gas injection port (5) is located above the light gas injection port (6) and is connected to the rich gas port. The light gas injection port (6) is connected to the light gas port.

7. A rich-lean combustion low-NOx burner, characterized in that, Includes the air-cooled structure as described in any one of claims 1 to 6.

8. The rich-lean combustion low-NOx burner according to claim 7, characterized in that, The burner also includes a burner plate (7), a front baffle (8), a rear baffle (9), and an air deflector (10); Multiple fire bars (7) are arranged in parallel and at intervals within a frame structure formed by a left side plate (2), a right side plate (3), a front baffle (8), a rear baffle (9), and an air guide plate (10), with a gas inlet (11) provided on the air guide plate (10).

9. The rich-lean combustion low-NOx burner according to claim 8, characterized in that, The gas inlet (11) is connected to the gas outlet (12) which is located inside the frame structure and corresponds to the gas ejector port of each fire row (7).

10. The rich-lean combustion low-NOx burner according to claim 8, characterized in that, The air guide plate (10) has a gas inlet (11) at the bottom center, and the bottom center of the air guide plate (10) protrudes downward.

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