Fuel staged injection low nitrogen burner

Abstract

The present invention discloses a fuel-staged injection type low-nitrogen burner, comprising an air chamber, an ignition assembly, a first gas assembly and a second gas assembly. The air chamber has an inner cavity, and a combustion-supporting gas inlet and an air outlet are arranged on the surface of the air chamber. The outer surface of the air chamber has a concave area, and at least part of the air outlets are distributed in the concave area. The ignition assembly passes through the air chamber, and the ignition end of the ignition assembly is located at the center of the concave area. The first gas assembly is used to supply gas to the inner cavity and the concave area at the same time. The ignition assembly comprises a Rafael nozzle, an ignition air gun, an igniter and a fire detector. The large-diameter end of the Rafael nozzle is located in the inner cavity, and the small-diameter end of the Rafael nozzle is located inside the concave area. The air outlet end of the ignition air gun is opposite to the large-diameter end of the Rafael nozzle, and the igniter and the fire detector are both arranged adjacent to the small-diameter end of the Rafael nozzle. Compared with the prior art, the burner of the present invention can not only reduce the nitrogen oxide content in the tail gas, but also improve the stability and sufficiency of the combustion process.

Description

Technical Field

[0001] The invention relates to the technical field of burners, and in particular to a fuel staged injection type low-nitrogen burner. Background Art

[0002] Nitrogen oxides (NO x ) is the main cause of photochemical smog and is also the main factor in the formation of acid rain, which seriously harms the atmospheric environment and human health. In addition, research results show that NOx is also an important source of atmospheric PM2.5 particles and is one of the main culprits causing haze weather. Therefore, how to design a burner head that can both reduce the content of nitrogen oxides in exhaust gas and improve the stability and sufficiency of the combustion process is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0003] The object of the present invention is to provide a fuel staged injection type low nitrogen burner which can not only reduce the nitrogen oxide content in the tail gas, but also improve the stability and sufficiency of the combustion process.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a fuel staged injection type low nitrogen burner, comprising:

[0006] An air chamber, wherein the air chamber has an inner cavity, a combustion-supporting gas inlet and an air outlet are arranged on the surface of the air chamber, and the combustion-supporting gas inlet and the air outlet are both connected to the inner cavity; the outer surface of the air chamber has a concave area, the number of the air outlets is multiple, and at least some of the air outlets are distributed in the concave area;

[0007] an ignition assembly, the ignition assembly passing through the air chamber, the ignition end of the ignition assembly being located at the center of the concave area;

[0008] A first gas component is used to supply gas to the inner cavity and the concave area at the same time

[0009] Wherein, the ignition assembly includes a Rafale nozzle, an ignition air gun, an igniter and a flame detector; the large diameter end of the Rafale nozzle is located in the inner cavity, and the small diameter end of the Rafale nozzle is located inside the concave area; the gas outlet end of the ignition air gun is directly opposite to the large diameter end of the Rafale nozzle, and a first injection gap is left between the large diameter end of the Rafale nozzle; the igniter and the flame detector are both arranged adjacent to the small diameter end of the Rafale nozzle.

[0010] Preferably, the first gas assembly includes a first distribution pipe, a first air inlet pipe and a first air gun; the first air inlet pipe is connected to the first distribution pipe to introduce gas into the first distribution pipe; there are multiple first air guns, and the multiple first air guns are all connected to the first distribution pipe to spray gas through the first air guns; the first air gun passes through the air chamber, the main air outlet end of the first air gun is located inside the concave area, and the secondary air outlet end of the first air gun is located in the inner cavity; the main air outlet ends of the multiple first air guns are in a ring shape surrounding the ignition end.

[0011] Preferably, the fuel-staged injection low-nitrogen burner also includes a second gas component, which includes a second distribution pipe, a second air inlet pipe, a second air gun and an ejector pipe; the second air inlet pipe is connected to the second distribution pipe to introduce gas into the second distribution pipe; there are multiple second air guns, and multiple second air guns are connected to the second distribution pipe to eject gas through the second air gun; the second air guns and the ejector pipe are both located outside the gas chamber, and the number of the second air guns and the ejector pipes is the same and corresponds one to one; the outlet end of the second air gun is opposite to the large diameter end of the ejector pipe, and a second ejection gap is left between the outlet end of the second air gun and the large diameter end of the ejector pipe; the small diameter ends of the multiple ejector pipes are circularly surrounding the concave area.

[0012] Preferably, a flange and a support plate are installed on the outer surface of the air chamber; the second air gun passes through the flange, and the ejection tube is fixed on the support plate.

[0013] Preferably, the middle portion of the second air gun is a hose section, and the hose section is located between the second distribution pipe and the flange.

[0014] Preferably, the air chamber is in the shape of a cylinder or a regular quadrangular prism; and the concave area is located on the end surface of the air chamber.

[0015] Preferably, some of the air outlet holes are distributed on the end surface of the air chamber where the concave area is located, and surround the concave area in a ring shape.

[0016] Preferably, the concave area includes a side surface and a bottom surface, and the side surface is a conical surface.

[0017] Preferably, per unit time, the proportion of gas introduced into the ignition component is 3-6%, the proportion of gas introduced into the first gas component is no more than 40%, and the proportion of gas introduced into the second gas component is no less than 55%.

[0018] Preferably, the calorific value of the gas fuel introduced into the ignition component, the first gas component and the second gas component is not less than 1500Kcal.

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

[0020] The ignition component uses a Lafarge nozzle with a Venturi effect to guide the combustion-supporting gas into the inner cavity and then burn it in the center of the concave area, achieving pre-mixing of the fuel gas and the combustion-supporting gas, effectively enhancing the flame stability and reducing the generation of nitrogen oxides.

[0021] After a portion of the gas provided by the first gas component enters the inner cavity, it is premixed with the combustion-supporting gas in the inner cavity. The mixed gas reaches the concave area through the gas outlet holes on the surface of the gas chamber. Another portion of the gas provided by the first gas component directly reaches the concave area. The two burn together around the ignition end of the ignition component. This structure can form an air excess coefficient greater than 2, effectively reduce the flame temperature, and thus effectively reduce the amount of nitrogen oxides generated.

[0022] The first gas component and the ignition component can not only be premixed with the combustion-supporting gas respectively, but also adopt different premixing methods, so as to achieve graded premixing of the central combustion area and the peripheral combustion area.

[0023] In a preferred embodiment of the present invention, the second gas component circulates the gas in the combustion furnace where it is located by means of injection, thereby diluting the oxygen concentration in the combustion furnace, which can effectively control the generation of nitrogen oxides. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0025] Figure 1 It is a schematic diagram of a fuel staged injection low-nitrogen burner according to an embodiment of the present invention.

[0026] In the figure: 1-second air inlet pipe; 2-first air inlet pipe; 3-igniter; 4-ignition air gun; 5-fire detection; 6-first distribution pipe; 7-first air gun; 8-combustion gas inlet; 9-air chamber; 10-second distribution pipe; 11-second air gun; 12-Rafale nozzle; 13-flange; 14-support plate; 15-injection tube. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The object of the present invention is to provide a fuel staged injection type low nitrogen burner, which can not only reduce the nitrogen oxide content in the tail gas, but also improve the stability and sufficiency of the combustion process.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Reference Figure 1 This embodiment provides a fuel-staged injection low-nitrogen burner, including an air chamber 9, an ignition component, a first gas component and a second gas component.

[0031] The air chamber 9 has an inner cavity, and a combustion-supporting gas inlet 8 and an air outlet are arranged on the surface of the air chamber 9, and the combustion-supporting gas inlet 8 and the air outlet are both connected to the inner cavity. The outer surface of the air chamber 9 has a concave area, and the number of the air outlets is multiple, and at least some of the air outlets are distributed in the concave area. The ignition component passes through the air chamber 9, and the ignition end of the ignition component is located at the center of the concave area. The first gas component is used to supply gas to the inner cavity and the concave area at the same time.

[0032] The ignition assembly includes a Rafale nozzle 12, an ignition air gun 4, an igniter 3 and a flame detector 5. The large diameter end of the Rafale nozzle 12 is located in the inner cavity, and the small diameter end of the Rafale nozzle 12 is located inside the concave area. The gas outlet end of the ignition air gun 4 is directly opposite to the large diameter end of the Rafale nozzle 12, and a first injection gap is left between the large diameter end of the Rafale nozzle 12. The igniter 3 and the flame detector 5 are both arranged adjacent to the small diameter end of the Rafale nozzle 12, and the small diameter end of the Rafale nozzle 12 is the ignition end of the ignition assembly.

[0033] Exemplarily, at the small-diameter end of the Rafale nozzle 12, spray holes are provided at the center and the conical surface thereof, the diameter of the spray hole is 1.5 mm to 5 mm, and the cone angle of the conical surface is 40° to 150°.

[0034] The working principle of the fuel staged injection type low nitrogen burner in this embodiment is as follows:

[0035] The ignition component uses a Lafarge nozzle 12 with a Venturi effect to inject the combustion-supporting gas into the inner cavity and then burn it in the center of the concave area, thereby achieving premixing of the fuel gas and the combustion-supporting gas, effectively enhancing flame stability, and reducing the generation of nitrogen oxides.

[0036] After a portion of the gas provided by the first gas component enters the inner cavity, it is premixed with the combustion-supporting gas in the inner cavity. The mixed gas reaches the concave area through the gas outlet holes on the surface of the gas chamber 9, and another portion of the gas provided by the first gas component directly reaches the concave area. The two burn together around the ignition end of the ignition component. This structure can form an air excess coefficient greater than 2, effectively reduce the flame temperature, and thus effectively reduce the amount of nitrogen oxides generated.

[0037] The first gas component and the ignition component can not only be premixed with the combustion-supporting gas respectively, but also adopt different premixing methods, so as to achieve graded premixing of the central combustion area and the peripheral combustion area.

[0038] As a possible example, in this embodiment, the first gas assembly includes a first distribution pipe 6, a first air inlet pipe 2 and a first gas gun 7. The first air inlet pipe 2 is connected to the first distribution pipe 6 to introduce gas into the first distribution pipe 6. There are multiple first gas guns 7, and the multiple first gas guns 7 are all connected to the first distribution pipe 6 to spray gas through the first gas guns 7. The first gas gun 7 passes through the gas chamber 9, the main gas outlet end of the first gas gun 7 is located inside the concave area, and the secondary gas outlet end of the first gas gun 7 is located in the inner cavity. The main gas outlet ends of the multiple first gas guns 7 are annularly surrounding the ignition end.

[0039] Exemplarily, the first air gun 7 is a straight tube, the main air outlet end is located at the end of the first air gun 7 away from the first distribution pipe 6, the secondary air outlet end is located on the side wall of the first air gun 7, and the diameter of the secondary air outlet end is 1.5mm to 5mm. The plurality of first air guns 7 are evenly distributed along the circumferential direction with the axis of the air chamber 9 as the center.

[0040] As a possible example, in this embodiment, the fuel staged injection type low nitrogen burner also includes a second gas assembly, and the second gas assembly includes a second distribution pipe 10, a second air intake pipe 1, a second air gun 11 and an ejection pipe 15. The second air intake pipe 1 is connected to the second distribution pipe 10 to pass gas into the second distribution pipe 10. There are multiple second air guns 11, and multiple second air guns 11 are connected to the second distribution pipe 10 to eject gas through the second air gun 11. The second air guns 11 and the ejection pipe 15 are both located outside the air chamber 9, and the number of the second air guns 11 and the ejection pipe 15 is the same and one-to-one. The gas outlet end of the second air gun 11 is directly opposite to the large diameter end of the ejection pipe 15, and a second ejection gap is left between the large diameter end of the ejection pipe 15. The small diameter ends of multiple ejection pipes 15 are annularly surrounding the concave area.

[0041] Exemplarily, the plurality of second air guns 11 are evenly distributed along the circumferential direction with the axis of the air chamber 9 as the center. The number of the first air guns 7 is not less than three, and the number of the second air guns 11 is not less than four.

[0042] The second gas component circulates the gas in the combustion furnace by means of injection, thereby diluting the oxygen concentration in the combustion furnace and effectively controlling the generation of nitrogen oxides. Through the combined action of the ignition component, the first gas component and the second gas component, the emission is controlled at 20mg / Nm 3 (3% oxygen content conversion value) or less.

[0043] When in use, the combustion-supporting gas is introduced into the inner cavity through the combustion-supporting gas inlet 8, and the combustion-supporting gas reaches the inner side of the concave area through the air outlet. The combustion-supporting gas is introduced into the ignition air gun 4, and the combustion-supporting gas in the ignition air gun 4 is ejected into the inner cavity and reaches the inner side of the concave area, and the gas ejected from the Rafale nozzle 12 is ignited by the igniter 3 to obtain a stable flame. Then, the combustion-supporting gas is introduced into the first air inlet pipe 2, 30% of which is mixed into the combustion-supporting gas in the inner cavity, and then reaches the concave area through the air outlet, and 70% of which is directly reached by the first air gun 7. Both gases are ignited by the stable flame to obtain an inner circle flame. After that, the combustion-supporting gas is introduced into the second air inlet pipe 1, and the combustion-supporting gas is ejected into the combustion furnace through the ejector pipe 15 to form an internal circulation of the flue gas. The gas flowing out of the ejector pipe 15 is ignited by the inner circle flame, and an outer circle flame is formed outside the inner circle flame.

[0044] In the above process, the gas on and off of the ignition gas gun 4, the first air inlet pipe 2 and the second air inlet pipe 1 are all controlled separately. The ignition gas gun 4 must be fed with gas, and at least one of the first air inlet pipe 2 and the second air inlet pipe 1 must be fed with gas. During the combustion process, the combustion status of the gas is detected by the fire detector 5.

[0045] As a possible example, in this embodiment, a flange 13 and a support plate 14 are installed on the outer surface of the air chamber 9. The second air gun 11 passes through the flange 13, and the ejection tube 15 is fixed on the support plate 14. The flange 13 and the support plate 14 are used to position the second air gun 11 so that the position of the second air gun 11 remains stable.

[0046] As a possible example, in this embodiment, the first distribution pipe 6 and the second distribution pipe 10 may be in the shape of a circular ring, a square ring, or an incomplete ring (similar to a C-shape).

[0047] As a possible example, in this embodiment, the middle portion of the second air gun 11 is a hose section, and the hose section is located between the second distribution pipe 10 and the flange 13 .

[0048] As a possible example, in this embodiment, the shape of the air chamber 9 is a cylinder or a regular quadrangular prism, and the concave area is located on the end surface of the air chamber 9. Exemplarily, the concave area is located at the center of the end surface, and the axis of the concave area is collinear with the axis of the air chamber 9.

[0049] As a possible example, in this embodiment, some of the air outlet holes are distributed on the end surface of the air chamber 9 where the concave area is located, and surround the concave area in a ring shape.

[0050] Exemplarily, the air outlet holes on the end surface of the air chamber 9 are distributed in a ring shape around the axis of the concave area, and the number is not less than one circle.

[0051] As a possible example, in this embodiment, the concave area includes a side surface and a bottom surface, and the side surface is a conical surface.

[0052] Exemplarily, the air outlet holes on the side surface of the concave region are distributed in a ring shape around the axis of the concave region, and the number of the holes is no less than three circles.

[0053] Exemplarily, the diameter of the air outlet hole is 2 mm to 20 mm.

[0054] As a possible example, in this embodiment, per unit time, the gas introduced into the ignition component accounts for 3-6%, the gas introduced into the first gas component accounts for no more than 40%, and the gas introduced into the second gas component accounts for no less than 55%.

[0055] As a possible example, in this embodiment, the calorific value of the gas fuel introduced into the ignition component, the first gas component and the second gas component is not less than 1500Kcal.

[0056] As a possible example, in this embodiment, the jet flow rate of the ignition air gun 4 is not less than 50 m / s, and the jet flow rate of the second air gun 11 is not less than 40 m / s.

[0057] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fuel staged injection low nitrogen burner, characterized in that: include: An air chamber, wherein the air chamber has an inner cavity, a combustion-supporting gas inlet and an air outlet are arranged on the surface of the air chamber, and the combustion-supporting gas inlet and the air outlet are both connected to the inner cavity; the outer surface of the air chamber has a concave area, the number of the air outlets is multiple, and at least some of the air outlets are distributed in the concave area; an ignition assembly, the ignition assembly passing through the air chamber, the ignition end of the ignition assembly being located at the center of the concave area; a first gas component, the first gas component being used to supply gas to the inner cavity and the inner concave area simultaneously; Wherein, the ignition assembly includes a Rafale nozzle, an ignition air gun, an igniter and a flame detector; the large diameter end of the Rafale nozzle is located in the inner cavity, and the small diameter end of the Rafale nozzle is located inside the concave area; the gas outlet end of the ignition air gun is directly opposite to the large diameter end of the Rafale nozzle, and a first injection gap is left between the large diameter end of the Rafale nozzle; the igniter and the flame detector are both arranged adjacent to the small diameter end of the Rafale nozzle.

2. The fuel staged injection low nitrogen burner according to claim 1 is characterized in that: The first gas component includes a first distribution pipe, a first air inlet pipe and a first air gun; the first air inlet pipe is connected to the first distribution pipe to introduce gas into the first distribution pipe; there are multiple first gas guns, and the multiple first gas guns are all connected to the first distribution pipe to spray gas through the first gas guns; the first gas gun passes through the gas chamber, the main gas outlet end of the first gas gun is located inside the concave area, and the secondary gas outlet end of the first gas gun is located in the inner cavity; the main gas outlet ends of the multiple first gas guns are in a ring shape surrounding the ignition end.

3. The fuel staged injection low nitrogen burner according to claim 1 is characterized in that: The fuel-staged injection low-nitrogen burner also includes a second gas component, which includes a second distribution pipe, a second air inlet pipe, a second air gun and an ejector pipe; the second air inlet pipe is connected to the second distribution pipe to introduce gas into the second distribution pipe; there are multiple second air guns, and multiple second air guns are connected to the second distribution pipe to eject gas through the second air gun; the second air guns and the ejector pipe are both located outside the gas chamber, and the number of the second air guns and the ejector pipes is the same and corresponds one to one; the gas outlet end of the second air gun is opposite to the large diameter end of the ejector pipe, and a second ejection gap is left between the large diameter end of the ejector pipe; the small diameter ends of multiple ejector pipes are arranged in a ring around the concave area.

4. The fuel staged injection low nitrogen burner according to claim 3 is characterized in that: A flange and a support plate are installed on the outer surface of the air chamber; the second air gun passes through the flange, and the ejection tube is fixed on the support plate.

5. The fuel staged injection type low nitrogen burner according to claim 4 is characterized in that: The middle part of the second air gun is a hose section, and the hose section is located between the second distribution pipe and the flange.

6. The fuel staged injection low nitrogen burner according to claim 1 is characterized in that: The shape of the air chamber is a cylinder or a regular quadrangular prism; the concave area is located on the end surface of the air chamber.

7. The fuel staged injection low nitrogen burner according to claim 6 is characterized in that: Some of the air outlet holes are distributed on the end surface of the air chamber where the concave area is located, and surround the concave area in a ring shape.

8. The fuel staged injection type low nitrogen burner according to claim 1 is characterized in that: The concave area includes a side surface and a bottom surface, and the side surface is a conical surface.

9. The fuel staged injection type low nitrogen burner according to claim 3 is characterized in that: In a unit time, the proportion of gas introduced into the ignition component is 3-6%, the proportion of gas introduced into the first gas component is not more than 40%, and the proportion of gas introduced into the second gas component is not less than 55%.

10. The fuel staged injection type low nitrogen burner according to claim 3 is characterized in that: The calorific value of the gas fuel introduced into the ignition component, the first gas component and the second gas component is not less than 1500Kcal.

Images