Main flame expansion type low-NOx gas burner nozzle suitable for flue gas internal circulation

Abstract

The invention discloses a main flame expansion type low-NOx gas burner nozzle suitable for internal circulation of flue gas, relates to the technical field of combustion equipment, and solves the problem that thermal NOx is generated by gas fuel combustion of a burner due to high flame temperature of the main flame expansion type low-NOx gas burner nozzle. The device comprises a central fuel channel, an air channel and a plurality of main fuel channels, wherein the central fuel channel, the air channel and the plurality of main fuel channels are arranged on a hearth wall; the air channel coaxially sleeves the outer side of the central fuel channel, and the plurality of main fuel channels are uniformly distributed on the outer side of the air channel in a radial circumference manner; the main fuel channel comprises a main fuel inlet channel and a main fuel sleeve, one end of the main fuel inlet channel is connected with the hearth wall, and the other end of the main fuel inlet channel is connected with the main fuel sleeve. And a plurality of main fuel pipe flue gas inlets are uniformly formed in the circumference of the main fuel sleeve. Fuel is input in a dispersed mode through a plurality of channels, meanwhile, smoke is sucked into the fuel channels in an entrainment mode, the flame temperature is reduced, and therefore generation of thermal type nitric oxide is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of combustion equipment, in particular to a main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas. Background Art

[0002] Under the background goal of "dual carbon", my country attaches more importance to the development and exploration of renewable energy. At present, natural gas has been widely used due to its advantages of high safety, high calorific value and low price. Hydrogen (H2) is a common carbon-free energy with low minimum ignition energy, wide flammable range, good economy and safety under lean combustion conditions. It has received more and more attention in recent years, so it is expected to become an alternative energy source to fossil energy. Natural gas blending with hydrogen can comprehensively utilize the advantages of natural gas and hydrogen, optimize the combustion characteristics of fuel, and is an effective solution to achieve the "dual carbon" goal in the gas field.

[0003] Although the combustion of gas fuel produces less pollutants than pulverized coal, it still produces thermal NOx due to its high flame temperature. Therefore, with the large-scale use of natural gas resources, how to reasonably control NOx emissions is a problem worthy of attention. Summary of the invention

[0004] In order to solve the problem of thermal NOx generated by gas fuel combustion due to the high flame temperature of the existing burners mentioned above, the present invention proposes a main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation. The present invention disperses the fuel input through a plurality of channels and simultaneously draws the flue gas into the fuel channel, thereby reducing the flame temperature and thus reducing the generation of thermal nitrogen oxides.

[0005] The present invention proposes a main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas, which specifically comprises a central fuel channel, an air channel and a plurality of main fuel channels, wherein the central fuel channel, the air channel and the plurality of main fuel channels are arranged on the furnace wall; the air channel is coaxially sleeved on the outside of the central fuel channel, and the plurality of main fuel channels are radially and circumferentially evenly arranged on the outside of the air channel; the main fuel channel comprises a main fuel inlet channel and a main fuel sleeve, wherein one end of the main fuel inlet channel is connected to the furnace wall, and the other end is connected to the main fuel sleeve; a plurality of main fuel pipe flue gas inlets are evenly arranged on the circumference of the main fuel sleeve.

[0006] Furthermore, a main fuel nozzle is arranged at the end of the main fuel inlet passage, and the main fuel nozzle is a tapered nozzle structure.

[0007] Furthermore, the starting position of the smoke inlet of the main fuel pipe is behind the outlet of the main fuel nozzle.

[0008] Furthermore, the opening rate of the main fuel pipe smoke inlet on the main fuel sleeve is 30%-70%.

[0009] Furthermore, the ratio of the cross-sectional area of ​​the main fuel inlet section to the main fuel casing is in the range of 2-4.

[0010] Furthermore, the angle between the axes of the main fuel channel and the central fuel channel is less than or equal to 20 degrees.

[0011] Furthermore, the distance between the main fuel sleeve and the air channel is less than or equal to 1 times the diameter of the main fuel sleeve.

[0012] Furthermore, the number of the main fuel channels is 3-16.

[0013] The beneficial effects of the main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation described in the present invention are:

[0014] (1) The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation of the present invention solves the problem of thermal NOx generated by gas fuel combustion due to the high flame temperature of the existing burner. The main fuel is input into several channels, which can increase the uniformity of the main flame, reduce the flame temperature, and thus reduce the generation of thermal nitrogen oxides;

[0015] (2) The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation described in the present invention has a main fuel pipe that expands outward in a radial shape, thereby expanding the cross-sectional area of ​​the main flame. On the one hand, it can avoid the high temperature generated by the concentrated flame, and on the other hand, it can also slow down the mixing speed of air and gas. The dual effect reduces the flame temperature and further reduces the generation of thermal nitrogen oxides.

[0016] (3) The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation described in the present invention has a main fuel nozzle arranged at the end of the main fuel pipe inlet section, which sucks high-temperature flue gas into the main fuel channel under the action of high-speed jet flow, dilutes the gas fuel concentration, and thus reduces the flame temperature, thereby controlling the generation of thermal nitrogen oxides;

[0017] (4) The main flame expansion type low NOx gas burner nozzle suitable for internal flue gas circulation described in the present invention has fuel supplied in two stages, namely, central fuel and main fuel. This can not only achieve fuel staged combustion to control the generation of nitrogen oxides, but also increase flame stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] In the attached picture:

[0020] Figure 1 It is a structural schematic diagram of a main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to the present invention;

[0021] Figure 2 It is a right view of the nozzle of a main flame expansion type low NOx gas burner suitable for internal circulation of flue gas according to the present invention;

[0022] Figure 3 It is a three-dimensional structural diagram of a main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to the present invention;

[0023] Among them: 1-central fuel channel, 2-air channel, 3-main fuel channel, 3-1-main fuel inlet section, 3-2-main fuel nozzle, 3-3-main fuel sleeve, 3-4-main fuel pipe smoke inlet. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0027] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Specific implementation method 1: See Figure 1-Figure 3 The present embodiment is described in detail. The main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas described in the present embodiment specifically includes a central fuel channel 1, an air channel 2 and a plurality of main fuel channels 3. The central fuel channel 1, the air channel 2 and the plurality of main fuel channels 3 are arranged on the furnace wall and extend into the furnace. By dispersing the main fuel into the furnace, the flame temperature is reduced, the uniformity of the main flame is improved, and the generation of thermal nitrogen oxides is reduced; the air channel 2 is coaxially sleeved on the outside of the central fuel channel 1; the plurality of main fuel channels 3 are radially and evenly arranged on the outside of the air channel 2, and the main fuel channel 3 connects one end of the furnace wall and the air channel 2. The distance is close, and the end of the main fuel channel 3 away from the furnace wall is far away from the air channel 2, thereby expanding the cross-sectional area of ​​the main flame. On the one hand, it can avoid the high temperature generated by the concentrated flame, and on the other hand, it also delays the mixing speed of air and fuel gas. The dual effect reduces the flame temperature and further reduces the generation of thermal nitrogen oxides; the main fuel channel 3 includes a main fuel inlet channel 3-1 and a main fuel sleeve 3-3, one end of the main fuel inlet channel 3-1 is connected to the furnace wall, and the other end is connected to the main fuel sleeve 3-3; a number of main fuel pipe smoke inlets 3-4 are evenly arranged on the circumference of the main fuel sleeve 3-3; the main fuel inlet channel 3-1 and the main fuel sleeve 3-3 are coaxially arranged.

[0029] A main fuel nozzle 3-2 is provided at the end of the main fuel inlet channel 3-1. The main fuel nozzle 3-2 is a tapered structure. When the fuel is sprayed into the main fuel sleeve 3-3 through the main fuel nozzle 3-2, a high-speed jet is formed. Under the action of the high-speed jet, the high-temperature flue gas is sucked into the main fuel channel to dilute the gas fuel concentration, thereby reducing the flame temperature and controlling the generation of thermal nitrogen oxides.

[0030] The starting position of the main fuel pipe smoke inlet 3-4 is behind the outlet of the main fuel nozzle 3-2, so as to ensure the entrainment effect of the formed high-speed jet on the smoke.

[0031] The opening rate of the main fuel pipe smoke inlet 3-4 on the main fuel sleeve 3-3 is 30%-70%.

[0032] The ratio of the cross-sectional area of ​​the main fuel inlet section 3-1 to the main fuel sleeve 3-3 is in the range of 2-4.

[0033] The included angle A between the axes of the main fuel channel 3 and the central fuel channel 1 is less than or equal to 20 degrees.

[0034] The distance H between the position of the main fuel sleeve 3 - 3 closest to the air channel 2 and the air channel 2 is less than or equal to 1 times the diameter of the main fuel sleeve 3 - 3 .

[0035] The number of the main fuel channels 3 is 3-16.

[0036] The entire gas burner nozzle is made of high temperature resistant materials, such as 316 stainless steel.

[0037] To summarize the above implementation cases, the main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas described in the present invention solves the problem of thermal NOx generated by combustion of gas fuel due to the high flame temperature of the existing burner, and the main fuel is input into several channels, which can increase the uniformity of the main flame, reduce the flame temperature, and thus reduce the generation of thermal nitrogen oxides; the main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas described in the present invention, the main fuel pipe 3 is radially expanded outward, which expands the cross-sectional area of ​​the main flame, which can avoid the high temperature generated by the concentrated flame on the one hand, and slow down the mixing speed of air and gas on the other hand, and the dual effect reduces Low flame temperature further reduces the generation of thermal nitrogen oxides; the main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas described in the present invention has a main fuel nozzle 3-2 arranged at the end of the main fuel pipe inlet section 3-1, which draws high-temperature flue gas into the main fuel channel under the action of high-speed jet to dilute the gas fuel concentration, thereby reducing the flame temperature and controlling the generation of thermal nitrogen oxides; the main flame expansion type low NOx gas burner nozzle suitable for internal circulation of flue gas described in the present invention has fuel supplied in two stages, namely central fuel and main fuel, which can realize staged combustion of fuel, thereby controlling the generation of nitrogen oxides, and can also increase flame stability.

[0038] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the invention. It can also be a reasonable combination of the features recorded in the above implementation methods. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation, characterized in that: The invention comprises a central fuel channel (1), an air channel (2) and a plurality of main fuel channels (3), wherein the central fuel channel (1), the air channel (2) and the plurality of main fuel channels (3) are arranged on the furnace wall; the air channel (2) is coaxially sleeved on the outside of the central fuel channel (1), and the plurality of main fuel channels (3) are radially and circumferentially evenly arranged on the outside of the air channel (2); the main fuel channel (3) comprises a main fuel inlet channel (3-1) and a main fuel sleeve (3-3), wherein one end of the main fuel inlet channel (3-1) is connected to the furnace wall, and the other end is connected to the main fuel sleeve (3-3); and a plurality of main fuel pipe smoke inlets (3-4) are evenly arranged on the circumference of the main fuel sleeve (3-3).

2. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 1, characterized in that: A main fuel nozzle (3-2) is arranged at the end of the main fuel inlet channel (3-1), and the main fuel nozzle (3-2) is a gradually contracting structure.

3. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 2, characterized in that: The starting position of the main fuel pipe smoke inlet (3-4) is behind the outlet of the main fuel nozzle (3-2).

4. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 1 or 3, characterized in that: The opening rate of the main fuel pipe smoke inlet (3-4) on the main fuel sleeve (3-3) is 30%-70%.

5. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​the main fuel inlet section (3-1) to that of the main fuel sleeve (3-3) is in the range of 2-4.

6. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 1, characterized in that: The included angle between the axes of the main fuel channel (3) and the central fuel channel (1) is less than or equal to 20 degrees.

7. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 1, characterized in that: The distance between the main fuel sleeve (3-3) and the air channel (2) is less than or equal to 1 times the diameter of the main fuel sleeve (3-3).

8. The main flame expansion type low NOx gas burner nozzle suitable for flue gas internal circulation according to claim 7, characterized in that: The number of the main fuel channels (3) is 3 to 16.

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