Wall-attached self-preheating low-nitrogen efficient combustor

Abstract

The invention relates to the technical field of combustors, and provides a wall-attached self-preheating low-nitrogen efficient combustor which comprises a shell and a combustor air duct brazier brick fixedly connected with the shell, a nozzle gun body is installed in the center of the shell, a combustor fan cover is installed outside the shell, a fuel pipe is installed in the center of the nozzle gun body, and a gas inlet is formed in the center of the fuel pipe. A throat ring, a swirl vane and a grating corner column are sequentially arranged on the fuel pipe, the throat ring is in sliding connection with the fuel pipe, the grating corner column is fixedly connected with the fuel pipe, and a special spray head is installed at the end, located in the burner air flue brazier brick, of the fuel pipe. The heat exchange turbulent flow conductor is arranged in the combustor fan cover, so that combustion air is self-preheated.

Description

Technical Field

[0001] The invention relates to the technical field of burners, in particular to a wall-mounted self-preheating low-nitrogen high-efficiency burner. Background Art

[0002] With the increasing awareness of environmental protection and the continuous improvement of air quality requirements, reducing the emission of nitrogen oxides (NOx) has become an important task. During the combustion process, the generation of nitrogen oxides has brought many negative impacts on the environment and human health. Traditional burners often produce higher concentrations of nitrogen oxides during the combustion process. In order to solve this problem, low-nitrogen burners came into being. Low-nitrogen burners adopt advanced combustion technology and design concepts to reduce the generation of nitrogen oxides during the combustion process. In the ethylene plant, the cracking furnace is the largest energy-consuming equipment, and the burner is an important part of the fuel consumption of the cracking furnace.

[0003] However, most of the traditional wall-mounted burners are easy to flame out, the flame is too long, and the wall attachment effect is poor. When the burner is burning, most of the flames are too concentrated, and the flames are attached to the furnace wall around the burner and cannot spread, resulting in the flame wall attachment area being centered. The furnace wall panel temperature is much higher than other areas, resulting in a high furnace wall temperature around the burner and a large heat dissipation loss, resulting in a large temperature gradient around the nozzle and uneven temperature distribution in the radiation furnace. The fuel-graded nozzle distribution ratio of some burners is difficult to adjust. After the operating conditions are adjusted, the NOx generated by the burner is not conducive to suppression, and NOx or CO is prone to exceed the standard. Some side wall burners using the premixed fuel method are limited in terms of flame shape, safety, and adjustment range, so the means and effects of controlling the flame range and suppressing the production of nitrogen oxides are relatively limited. Summary of the invention

[0004] The invention provides a wall-mounted self-preheating low-nitrogen high-efficiency burner, which solves the problems existing in the background technology through special nozzles and swirl blades.

[0005] The technical solution of the present invention is as follows: A wall-mounted self-preheating low-nitrogen high-efficiency burner comprises: an outer shell, a burner air duct fire basin brick fixedly connected to the outer shell, a nozzle gun body is installed at the center of the outer shell, and the nozzle gun body passes through the outer shell and the burner air duct fire basin brick, a burner air hood is installed outside the outer shell, an air damper main valve and an air damper fine-tuning valve are respectively provided on the outer shell and the burner air duct fire basin brick, the air damper main valve and the air damper fine-tuning valve can open the communication channel between the outer shell and the burner air duct fire basin brick and the burner air hood, a fuel pipe is installed at the center of the nozzle gun body, a roar ring, a swirl blade and a grille corner column are sequentially provided on the fuel pipe, the roar ring is slidably connected to the fuel pipe, the grille corner column is fixedly connected to the fuel pipe, a special nozzle is installed at one end of the fuel pipe located in the burner air duct fire basin brick, and the grille corner column is close to the special nozzle.

[0006] Preferably, the nozzle gun body comprises arc tube 1, straight tube 1, arc tube 2 and straight tube 2 which are arranged in sequence, the straight tube 2 is provided with multiple rows of ventilation holes, and a venturi tube is installed at one end of the arc tube 1.

[0007] Preferably, a heat exchange spoiler conductor is provided in the burner hood, and the heat exchange spoiler conductor is an elastic steel wire mesh. An air inlet is provided on the burner hood, and the air inlet is annular with a gap of 15 cm.

[0008] Preferably, a rain shield is provided on the upper portion of the burner hood.

[0009] Preferably, the roar ring is located between the straight tube 1 and the arc-shaped tube 2, and the roar ring is conical and has the same arc as that of the arc-shaped tube 2.

[0010] Preferably, the special nozzle includes a primary combustion head and a secondary combustion head installed on the head of the fuel pipe, the primary combustion head is installed with a flame stabilizing disk, the two ends of the secondary combustion head are respectively fixedly connected to the fuel pipe and the flame stabilizing disk and pass through the fuel pipe and the flame stabilizing disk, the secondary combustion head is an arc curve, and multiple rows of fire holes are provided on the secondary combustion head, the fire holes are located on the side of the flame stabilizing disk away from the secondary combustion head, and the flame stabilizing disk is provided with multiple reflux holes.

[0011] Preferably, a fire hole nozzle is fixedly connected to the secondary combustion head and located at the fire hole, and the fire hole nozzle forms a certain angle with the secondary combustion head.

[0012] Preferably, the special nozzle extends out of one end of the burner air duct fire basin brick.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a heat exchange spoiler conductor in the burner hood. The heat exchange spoiler conductor is made of elastic wire mesh filler and can be adsorbed on the furnace wall plate. At the same time, the heat exchange spoiler conductor exchanges the overheated heat outside the furnace wall plate and self-preheats the combustion air. The heated combustion air is more fully mixed with the fuel, which can reduce the local high temperature of the furnace wall plate and reduce the heat dissipation loss of the cracking furnace, thereby improving the thermal efficiency of the heating furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the installation of the burner of the present invention; Figure 2 is a perspective view of a burner of the present invention; Figure 3 is a cross-sectional perspective view of a burner of the present invention; Figure 4 It is a stereoscopic view of the front side of the fuel pipe structure of the present invention.

[0015] In the figure: 1. Shell; 2. Burner air duct brazier brick; 3. Nozzle gun body; 31. Arc tube one; 32. Straight tube one; 33. Arc tube two; 34. Straight tube two; 35. Ventilation hole; 36. Venturi tube; 4. Burner hood; 41. Heat exchange turbulence conductor; 42. Air inlet; 43. Rain shield; 5. Air damper main valve; 6. Air damper fine-tuning valve; 7. Fuel pipe; 8. Roar ring; 9. Swirl blade; 10. Grille corner column; 11. Special nozzle; 111. Primary combustion head; 112. Secondary combustion head; 113. Flame stabilizing disk; 114. Fire hole; 115. Reflux hole; 116. Fire hole nozzle; 12. Furnace wall panel. DETAILED DESCRIPTION

[0016] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Example

[0017] like Figure 1-3 As shown, the present invention provides a wall-mounted self-preheating low-nitrogen high-efficiency burner, comprising: a shell 1, a burner air duct brazier brick 2 fixedly connected to the shell 1, the burner is installed on the furnace wall plate 12 through the burner air duct brazier brick 2, a nozzle gun body 3 is installed at the center of the shell 1, and the nozzle gun body 3 passes through the shell 1 and the burner air duct brazier brick 2, a burner wind cover 4 is installed outside the shell 1, and the shell 1 and the burner air duct brazier brick 2 are respectively provided with a damper main valve 5 and a damper fine-tuning valve 6, and the damper The main valve 5 and the air door fine adjustment valve 6 can open the communication channel between the housing 1 and the burner air duct fire basin brick 2 and the burner air cover 4. A fuel pipe 7 is installed at the center of the nozzle gun body 3. A roar ring 8, a swirl blade 9 and a grille corner column 10 are sequentially arranged on the fuel pipe 7. The roar ring 8 is slidably connected to the fuel pipe 7. The grille corner column 10 is fixedly connected to the fuel pipe 7. A special nozzle 11 is installed at one end of the fuel pipe 7 located in the burner air duct fire basin brick 2, and the grille corner column 10 is close to the special nozzle 11. The combustion air is naturally introduced through the burner hood 4. The main air damper valve 5 is opened to allow most of the combustion air to enter the outer casing 1 and flow into the nozzle gun body 3. A large amount of combustion air enters the nozzle gun body 3 and is transmitted to the special nozzle 11. The special nozzle 11 sprays the fuel in the fuel pipe 7, contacts the combustion air in the nozzle gun body 3, and ignites the fuel through the igniter. The air damper fine-tuning valve 6 is adjusted to allow a small amount of combustion air to enter the burner air duct brazier brick 2 and be transmitted to the special nozzle 11 for air distribution. During the transmission process of the combustion air from the nozzle gun body 3, the roar ring 8 controls the flow rate of the combustion air, and the swirl blades 9 are used to swirl the combustion air to fully mix the combustion air and the fuel.

[0018] like Figure 3As shown, the nozzle gun body 3 includes an arc tube 1 31, a straight tube 1 32, an arc tube 2 33, and a straight tube 2 34 which are arranged in sequence. The arc tube 1 31, the straight tube 1 32, the arc tube 2 33, and the straight tube 2 34 form a venturi tube shape. When the combustion air flows from the arc tube 1 31 with a larger space through the narrow straight tube 1 32, the flow rate decreases and the flow velocity increases. According to the Bernoulli principle, the flow velocity increases and the pressure decreases, thereby forming a low pressure area at the straight tube 1 32, so that a pressure difference is formed at both ends of the straight tube 1 32, increasing the pressure of the combustion air, and making the combustion air contact with the fuel more fully; as shown in FIG. Figure 3 As shown, a ventilation hole 4 35 is provided on the straight pipe 2 34, so that a small amount of combustion-supporting air enters from the gap between the burner air duct brazier brick 2 and the nozzle gun body 3, and flows to the special nozzle 11 through the ventilation hole 4 35 to fine-tune the flame; Figure 3 As shown, a venturi tube 36 is installed at one end of the arc tube 31, so that the combustion air entering from the burner wind hood 4 is pressurized and accelerated through the venturi tube 36 to enter the nozzle gun body 3, and the Reynolds number can be adjusted within a suitable range according to local air pressure conditions.

[0019] like Figure 1 As shown, a heat exchange spoiler conductor 41 is provided in the burner hood 4. The heat exchange spoiler conductor 41 is made of elastic steel wire mesh filler and can be adsorbed on the furnace wall panel 12. At the same time, the heat exchange spoiler conductor 41 absorbs and stores the overheated heat outside the furnace wall panel 12, and self-preheats the combustion air entering the burner hood 4, so that the burner hood 4 is in a thermal equilibrium state. The heated combustion air enters the nozzle gun body 3 to assist combustion. This can not only reduce the local high temperature of the furnace wall panel 12, but also reduce the heat dissipation loss of the cracking furnace, thereby greatly improving the thermal efficiency of the heating furnace.

[0020] The burner hood 4 is provided with an air inlet 42 which is in the shape of a ring with a gap of 15 cm, so as to form a negative pressure and draw the external gas into the burner hood 4, thereby preheating the air.

[0021] A rain shield 43 is provided on the upper portion of the burner hood 4 to prevent rainwater from entering the burner hood 4 .

[0022] like Figure 3 As shown, the roar ring 8 is located between the straight tube 1 32 and the arc tube 2 33, and the roar ring 8 is conical and the curvature is the same as the curvature of the arc tube 2 33, so that when the combustion air flows out from the gap between the roar ring 8 and the arc tube 2 33, it flows to the edge of the arc tube 2 33. Because the Venturi tube principle makes the flow pressure between the straight tube 1 32 and the arc tube 2 33 larger, the combustion air has greater power to flow from here to the edge, thereby making the combustion air contact with the fuel more fully.

[0023] like Figure 4As shown, the special nozzle 11 includes a primary combustion head 111 and a secondary combustion head 112 installed at the head of the fuel pipe 7. A flame stabilizing disk 113 is installed on the primary combustion head 111. Both ends of the secondary combustion head 112 are respectively fixedly connected to the fuel pipe 7 and the flame stabilizing disk 113 and pass through the fuel pipe 7 and the flame stabilizing disk 113. The secondary combustion head 112 is an arc-shaped curve. A plurality of rows of fire holes 114 are provided on the secondary combustion head 112. The fire holes 114 are located on the side of the flame stabilizing disk 113 away from the secondary combustion head 112. A plurality of reflux holes 115 are provided on the flame stabilizing disk 113.

[0024] The fuel in the fuel pipe 7 flows out from the primary combustion head 111 and the secondary combustion head 112 respectively, and contacts the combustion-supporting air flowing in from the gap between the straight tube 2 34 and the flame stabilizing disk 113, and ignites the fuel through the igniter to achieve heating; the secondary combustion head 112 is set to be an arc curve, so that the flame area of ​​the burner attached to the wall is expanded, which is 30% to 40% larger than the traditional area, and the flame is stronger. At the same time, the gradient of the temperature field around the burner flame area is reduced, thereby reducing heat loss. The smoke generated by the combustion flows from the reflow hole 115 to the grille corner column 10, and the smoke is refluxed to the inner wall of the straight tube 2 34 through the grille corner column 10, and is driven by the combustion-supporting air to re-enter the combustion area on one side of the flame stabilizing disk 113 for sufficient combustion, thereby reducing the generation of oxygen-containing nitrogen compounds; the combustion-supporting air is evenly distributed through the grille corner column 10, so that the combustion-supporting air and the fuel are more fully mixed.

[0025] A fire hole nozzle 116 is fixedly connected to the secondary combustion head 112 and located at the fire hole 114 , and the fire hole nozzle 116 forms a certain angle with the secondary combustion head 112 .

[0026] Due to the influence of combustion speed, flashback may occur when the heat load is low or the fuel composition changes greatly. In order to prevent flashback, the special nozzle 11 correctly selects the distance, number, angle and length of the fire holes 114 according to the load adjustment ratio, gas composition and primary air coefficient, which can effectively control the flame to stick to the wall, be flat and round, and be strong and stable.

[0027] The special nozzle 11 extends out of one end of the burner air duct fire basin brick 2, and the length is about 20mm to 30mm longer than the traditional burner. The flame area of ​​the burner attached to the wall will be expanded; the expansion of the flame area will reduce the temperature gradient around the burner, reduce the thermal stress of the steel structure around the burner, and the expansion of the flame area will make the furnace tube heated more evenly.

[0028] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A wall-mounted self-preheating low-nitrogen high-efficiency burner, comprising: A shell (1) and a burner air duct brazier brick (2) fixedly connected to the shell (1), characterized in that: a nozzle gun body (3) is installed at the center of the shell (1), and the nozzle gun body (3) passes through the shell (1) and the burner air duct brazier brick (2), a burner air hood (4) is installed outside the shell (1), and a damper main valve (5) and a damper fine-tuning valve (6) are respectively provided on the shell (1) and the burner air duct brazier brick (2), and the damper main valve (5) and the damper fine-tuning valve (6) can open the shell (1) and the burner air duct A communication passage between the fire basin brick (2) and the burner air hood (4); a fuel pipe (7) is installed at the center of the nozzle gun body (3); a roar ring (8), a swirl blade (9) and a grille corner column (10) are arranged on the fuel pipe (7) in sequence; the roar ring (8) is slidably connected to the fuel pipe (7); the grille corner column (10) is fixedly connected to the fuel pipe (7); a special nozzle (11) is installed at one end of the fuel pipe (7) located in the burner air duct fire basin brick (2), and the grille corner column (10) is close to the special nozzle (11).

2. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 1 is characterized in that: The nozzle gun body (3) comprises an arc tube 1 (31), a straight tube 1 (32), an arc tube 2 (33), and a straight tube 2 (34) which are arranged in sequence, wherein the straight tube 2 (34) is provided with a plurality of rows of ventilation holes (35), and a venturi tube (36) is installed at one end of the arc tube 1 (31).

3. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 1 is characterized in that: A heat exchange spoiler conductor (41) is arranged in the burner wind hood (4), and the heat exchange spoiler conductor (41) is an elastic steel wire mesh. An air inlet (42) is arranged on the burner wind hood (4), and the air inlet (42) is annular, and has a gap of 15 cm.

4. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 1 is characterized in that: A rain shield (43) is provided on the upper portion of the burner wind hood (4).

5. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 2 is characterized in that: The roar ring (8) is located between the straight tube 1 (32) and the arc-shaped tube 2 (33), and the roar ring (8) is conical and has the same arc as that of the arc-shaped tube 2 (33).

6. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 1 is characterized in that: The special nozzle (11) comprises a primary combustion head (111) and a secondary combustion head (112) mounted on the head of a fuel pipe (7); a flame stabilizing disk (113) is mounted on the primary combustion head (111); two ends of the secondary combustion head (112) are respectively fixedly connected to the fuel pipe (7) and the flame stabilizing disk (113) and pass through the fuel pipe (7) and the flame stabilizing disk (113); the secondary combustion head (112) is in an arc-shaped curve shape; a plurality of rows of fire holes (114) are provided on the secondary combustion head (112); the fire holes (114) are located on a side of the flame stabilizing disk (113) away from the secondary combustion head (112); and a plurality of reflux holes (115) are provided on the flame stabilizing disk (113).

7. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 5 is characterized in that: A fire hole nozzle (116) is fixedly connected to the secondary combustion head (112) and located at the fire hole (114); the fire hole nozzle (116) forms a certain angle with the secondary combustion head (112).

8. The wall-mounted self-preheating low-nitrogen high-efficiency burner according to claim 6 is characterized in that: The special nozzle (11) extends out from one end of the burner air duct fire basin brick (2).

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