Low NOx Burner

Abstract

A low nitrogen oxide burner is disclosed. The disclosed low nitrogen oxide burner can significantly reduce the amount of nitrogen oxides generated by reducing the temperature of the flame by using flame segmentation technology, mixing promotion technology, multi-stage combustion technology and internal recirculation technology. Specifically, the low nitrogen oxide burner according to an embodiment of the present invention can reduce the temperature of the flame by applying flame segmentation technology and internal recirculation technology, thereby reducing the amount of nitrogen oxides generated. Here, flame segmentation corresponds to separately generating an internal flame based on an internal fuel pipe and an external flame based on an external fuel pipe, and the internal recirculation technology can be achieved based on the use of a swirler and the flow rate difference of air supplied to the internal fuel pipe and the external fuel pipe, respectively.

Description

Technical Field

[0001] The present invention relates to a method for reducing nitrogen oxides (NO X ) produced by the burner. Background Art

[0002] Nitrogen oxides generally refer to nitric oxide (NO) and nitrous oxide (NO2), commonly referred to as NO X NO is a colorless, odorless, toxic gas. NO2 is an absorber of visible light, and is brown due to the absorption of short waves such as purple to blue. It is a toxic gas with corrosive and strong irritating odor.

[0003] When burning fossil fuels, a large amount of nitrogen oxides are produced. Nitrogen oxides are divided into: thermal nitrogen oxides (TNO) produced by oxidizing nitrogen molecules in the combustion air when nitrogen in the combustion air is freed at high temperatures. X ), fuel NOx generated by oxidation of nitrogen components in the fuel during combustion X Prompt NOx (prompt NOx) is generated by the reaction of hydrocarbon gases produced during fuel combustion with nitrogen in the combustion air. X )wait.

[0004] The biggest hazard of nitrogen oxides is that they participate in the formation of photochemical smog, reacting with hydrocarbons in the sun to produce photochemical oxides and ozone. In addition to ozone, smog pollutants such as PAN (Peroxyacetylnitrate) can also cause coughing, eye irritation, headaches and severe throat irritation.

[0005] Therefore, emission reduction technologies for reducing nitrogen oxides are studied and developed.

[0006] On the other hand, conventional high-power absorption water heaters are called industrial chillers, which are devices that control water at a certain temperature and circulate the water at the controlled temperature to cool a heat source or adjust the temperature. In particular, a burner is used to control the temperature of the water. Since the burner also burns fossil fuels, it is necessary to reduce nitrogen oxides.

[0007] The burners used in traditional high-power absorption water heaters are turbulent diffusion flame burners. Due to atmospheric environmental regulations, high-power absorption water heaters using burners above 410RT must meet the "40ppm@O24%" regulation.

[0008] The low nitrogen oxide burner is a burner that combines fuel and oxygen to improve the burner form to suppress the generation of nitrogen oxides. As a prior patent related to the low nitrogen oxide burner, there is Korean registered patent No. 10-1697123 (invention name: low nitrogen oxide burner).

[0009] However, the prior patent is a burner using a diffusion flame, and the burner uses magnetic recirculation technology to reduce the flame temperature. However, when the capacity of the combustion chamber is large, the temperature of the flame increases, thereby causing a problem of increased generation of nitrogen oxides. Summary of the invention

[0010] An object of the present invention is to provide a low nitrogen oxide burner which can significantly reduce the amount of nitrogen oxides produced.

[0011] In addition, an object of the present invention is to provide a low nitrogen oxide burner capable of effectively reducing the temperature of the flame.

[0012] Furthermore, an object of the present invention is to provide a low nitrogen oxide burner that effectively generates internal recirculation by adjusting the air flow rate used in the combustion process or using a swirler.

[0013] The purpose of the present invention is not limited to the above-mentioned purpose. Other purposes and advantages of the present invention that are not mentioned can be understood through the following description and can be more clearly understood with the help of the embodiments of the present invention.

[0014] The low nitrogen oxide burner according to an embodiment of the present invention can significantly reduce the amount of nitrogen oxide generated by using flame segmentation technology, mixing promotion technology, multi-stage combustion technology and internal recirculation technology.

[0015] Specifically, the low nitrogen oxide burner according to an embodiment of the present invention can reduce the temperature of the flame by applying the flame segmentation technology and the internal recirculation technology, thereby reducing the amount of nitrogen oxides generated. Here, the flame segmentation corresponds to the separate generation of an internal flame based on an internal fuel pipe and an external flame based on an external fuel pipe, and the internal recirculation technology can be realized based on the use of a swirler and the flow rate difference of air supplied to the internal fuel pipe and the external fuel pipe, respectively.

[0016] In addition, the low nitrogen oxide burner according to an embodiment of the present invention can make the inner flame too rich and the outer flame too lean, thereby reducing the amount of nitrogen oxide generated.

[0017] In addition, the low nitrogen oxide burner according to an embodiment of the present invention uses a swirler and makes the fuel injected from the fuel port intersect the air vertically to promote the mixing of the fuel and the air, thereby reducing the amount of nitrogen oxide generated.

[0018] A low nitrogen oxide burner according to one embodiment of the present invention includes: a tube, one end of which is exposed to the combustion chamber and guides air; an internal fuel pipe, which is arranged inside the tube and has an internal fuel port for generating an internal flame formed at one end of the internal fuel pipe; an external fuel pipe, which is arranged inside the tube and has an external fuel port for generating an external flame formed at one end of the external fuel pipe; a guide portion, which is arranged between the internal fuel pipe and the external fuel pipe and supplies the air to the internal fuel port; a first diffuser, which is provided with one end of the guide portion and one end of the external fuel pipe and supplies the air to the external fuel port; and a swirler, which is arranged inside one end of the guide portion and has one end of the internal fuel pipe provided at the center of the swirler.

[0019] In addition, a low nitrogen oxide burner according to another embodiment of the present invention includes: a tube, one end of which is exposed to the combustion chamber and guides air; an internal fuel pipe, which is arranged inside the tube and has an internal fuel port for generating an internal flame formed at one end of the internal fuel pipe; an external fuel pipe, which is arranged inside the tube and has an external fuel port for generating an external flame formed at one end of the external fuel pipe; a guide portion, which is arranged between the internal fuel pipe and the external fuel pipe and has a plurality of second air holes for supplying the air to the internal fuel pipe; and a diffuser, in which the external fuel pipe is mounted and has a plurality of first air holes for supplying the air to the external fuel pipe, and based on the sizes of the plurality of second air holes and the sizes of the plurality of first air holes, the internal flame is burned at an overly rich concentration above a preset concentration, and the external flame is burned at a lean concentration below a preset concentration.

[0020] According to the present invention, by using a multi-stage combustion technology that generates an over-rich inner flame and a lean outer flame, the temperature of the flame can be reduced, and ultimately, the amount of nitrogen oxide generated can be reduced.

[0021] According to the present invention, by separately generating an inner flame based on an inner fuel pipe and an outer flame based on an outer fuel pipe, the temperature of the flame can be lowered, and eventually, the amount of nitrogen oxide generated can be reduced.

[0022] According to the present invention, by using a swirler and making the flow rates of air supplied to the inner fuel pipe and the outer fuel pipe different, the temperature of the flame can be reduced, and ultimately, the amount of nitrogen oxide generated can be reduced.

[0023] According to the present invention, by making air intersect the fuel injected from the fuel port vertically and using a swirler, the temperature of the flame can be locally reduced, and ultimately, the amount of nitrogen oxide generated can be reduced.

[0024] Hereinafter, specific modes for carrying out the present invention will be described together with the above-mentioned effects and specific effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a diagram showing a perspective view of a low nitrogen oxide burner according to an embodiment of the present invention.

[0026] Figure 2 1 is a diagram showing a perspective view of a burner combustion head according to an embodiment of the present invention.

[0027] Figure 3 1 is a diagram showing an exploded perspective view of a burner combustion head according to an embodiment of the present invention.

[0028] Figure 4 It is a diagram showing a perspective cross-sectional view of a burner combustion head according to an embodiment of the present invention.

[0029] Figure 5 FIG. 1 is a diagram showing a perspective view of a guide portion according to an embodiment of the present invention.

[0030] Figures 6 to 8 It is a diagram for explaining the concepts of flame division, mixing promotion, multi-stage combustion, and internal recirculation according to an embodiment of the present invention.

[0031] Description of Reference Numerals

[0032] 100: Low NOx burner 110: Burner housing

[0033] 120: Burner head 201: Air supply pipe

[0034] 210: Main fuel pipe 211: Through hole

[0035] 220: fuel chamber 221: first fuel chamber

[0036] 221a: first main body 221b: first connecting portion

[0037] 221c: connection hole 222: second fuel chamber

[0038] 222a: second main body 222b: second connection portion

[0039] 230: Internal fuel pipe 231: Internal fuel port

[0040] 240: External fuel pipe 241: External fuel port

[0041] 250: guide part 251: internal diffuser

[0042] 252: Step portion 251a: Second air hole

[0043] 260: External diffuser 261: Mounting hole

[0044] 262: First air hole 270: Swirl

[0045] 271: Wing 280: Position moving part

[0046] 291: Ignition device 292: Flame detection rod

[0047] 293: First retainer 294: Second retainer

[0048] 810: First internal recirculation 820: Second internal recirculation

[0049] 830: Combustion Chamber DETAILED DESCRIPTION

[0050] The aforementioned objects, features and advantages are described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement the technical ideas of the present invention. In the process of describing the present invention, when it is determined that the specific description of the known technology related to the present invention will obscure the main purpose of the present invention, its detailed description is omitted. Below, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components.

[0051] Although the terms "first", "second", etc. are used to describe multiple components, these components are not limited to these terms. These terms are used only to distinguish one component from another component. Unless otherwise specified, the first component can also be the second component.

[0052] In the following text, the arrangement of any structure "on the top (or bottom)" or "above (or below)" a constituent element may not only refer to configuring any structure to be in contact with the top surface (or bottom surface) of the constituent element, but may also refer to that other structures may be sandwiched between the constituent element and any structure configured above (or below) the constituent element.

[0053] In addition, when it is recorded that a certain constituent element is “coupled”, “combined” or “connected” to other constituent elements, it should be understood that the above-mentioned constituent elements can be directly coupled or connected to each other, and another constituent element can be “sandwiched” between the constituent elements, or each constituent element can be “coupled”, “combined” or “connected” using other constituent elements.

[0054] Throughout the specification, unless otherwise specified, each constituent element may be in the singular or in the plural.

[0055] In addition, unless the context clearly stipulates otherwise, the singular expressions used in this specification include plural expressions. In this application, the term "consisting of" or "comprising" etc. should not be interpreted as necessarily including all the various constituent elements or steps described in the specification, but should be interpreted as not including some constituent elements or steps, or further including other constituent elements or steps.

[0056] Hereinafter, a low nitrogen oxide burner according to some embodiments of the present invention will be described.

[0057] Figure 1 FIG. 1 is a diagram showing a perspective view of a low nitrogen oxide burner according to an embodiment of the present invention.

[0058] Reference Figure 1 A low nitrogen oxide burner according to an embodiment of the present invention includes a burner housing 110 and a burner combustion head 120 .

[0059] The burner housing 110 constitutes a main body of the low NOx burner. A blower (not shown) may be disposed inside the burner housing 110 to supply external air to the burner combustion head 120. In addition, components for supplying fuel may be disposed inside the burner housing 110.

[0060] The burner combustion head 120 is combined with the burner housing 110 and generates flames. One end of the burner combustion head 120 is disposed in a combustion chamber (not shown) to generate flames into the combustion chamber.

[0061] The burner combustion head 120 includes a tube or air supply pipe 201. One end of the air supply pipe 201 is exposed to the combustion chamber to guide the air provided by the blower to the combustion chamber. The components for generating flames are arranged in the air supply pipe 201, and the final shape of the flame is determined based on the shape of the air supply pipe 201.

[0062] Figure 2 FIG. 1 is a perspective view of a burner combustion head 120 according to an embodiment of the present invention. Figure 3 FIG. 1 is a diagram showing an exploded perspective view of a burner combustion head 120 according to an embodiment of the present invention. Figure 4 1 is a diagram showing a perspective cross-sectional view of a burner combustion head 120 according to an embodiment of the present invention. For ease of explanation, Figure 2 and Figure 3 The air supply duct 201 is not shown.

[0063] Reference Figures 2 to 4According to an embodiment of the present invention, the burner head 120 includes: a main fuel pipe 210, a fuel chamber 220, an internal fuel pipe 230, an external fuel pipe 240, a guide 250, an external diffuser 260, a swirler 270, a position moving part 280, an igniter 291, and a flame detection rod 292. At this time, Figures 2 to 4 The components shown are arranged in Figure 1 The internal space of the air supply pipe 201 is shown.

[0064] The main fuel pipe 210 supplies fuel to the burner combustion head 120. The interior of the main fuel pipe 210 is empty, and the fuel can flow into the empty interior space. The fuel can be a gaseous fuel.

[0065] Reference Figures 2 to 4 The main fuel pipe 210 may be L-shaped. At least a portion of the main fuel pipe 210 may be disposed inside the air supply pipe 201. One end of the main fuel pipe 210 may be connected to the other end of the fuel chamber 220, and fuel may be supplied from the other end of the main fuel pipe 210.

[0066] On the other hand, a through hole 211 may be formed between one end and the other end of the main fuel pipe 210. The position moving part 280 may be inserted into the inside of the through hole 211. This will be described in more detail below.

[0067] The fuel chamber 220 may transfer or supply the fuel supplied from the main fuel pipe 210 to the internal fuel pipe 230 and the external fuel pipe 240. The internal fuel pipe 230 and the external fuel pipe 240 may be branched from one end of the fuel chamber 220, and the other end of the fuel chamber 220 may be combined with one end of the main fuel pipe 210. For example, the other end of the fuel chamber 220 may be inserted into the inside of one end of the main fuel pipe 210.

[0068] The fuel chamber 220 includes a first fuel chamber 221 and a second fuel chamber 222. The first fuel chamber 221 and the second fuel chamber 222 may be combined with each other. The first fuel chamber 221 may correspond to the other end of the fuel chamber 220, and the second fuel chamber 222 may correspond to one end of the fuel chamber 220.

[0069] The first fuel chamber 221 includes a first body portion 221a and a first connecting portion 221b. The first connecting portion 221b is connected to one end of the first body portion 221a. The first body portion 221a can be inserted into the interior of one end of the main fuel pipe 210. For example, one end of the main fuel pipe 210 and the first body portion 221a can both have a cylindrical shape with a hollow interior. In this case, the diameter of the cylinder corresponding to one end of the main fuel pipe 210 is larger than the diameter of the cylinder corresponding to the first body portion 221a, and finally, the first body portion 221a can be inserted into the interior of the main fuel pipe 210. The first connecting portion 221b can be a ring shape, combined with the second connecting portion 222b to be described below.

[0070] On the other hand, at least one connection hole 221c may be formed on the side of the first body portion 221a. The connection hole 221c may be used to connect the position moving portion 280 to be described below and the first body portion 221a. This will be described in further detail below.

[0071] The second fuel chamber 222 includes a second body portion 222a and a second connection portion 222b. The second connection portion 222b is coupled to the other end of the second body portion 222a. The second connection portion 222b is connected to the first connection portion 221b. Therefore, the fuel is transported or supplied from the first fuel chamber 221 to the second fuel chamber 222.

[0072] The second connection portion 222b may have a ring shape similar to the first connection portion 221b. The second body portion 222a is combined with the second connection portion 222b and is a constituent element for branching the internal fuel pipe 230 and the external fuel pipe 240. The external fuel pipe 240 may branch out from the side of the second body portion 222a, and the internal fuel pipe 230 may branch out from one end of the second body portion 222a.

[0073] The internal fuel pipe 230 and the external fuel pipe 240 are used to transport the fuel supplied from the fuel chamber 220 to the respective fuel ports 231 and 241. The internal fuel pipe 230 may be disposed at the center of the air supply pipe 201, and the external fuel pipe 240 may be disposed at the edge of the air supply pipe 201.

[0074] The internal fuel pipe 230 includes a plurality of internal fuel ports 231 for generating internal flames. Fuel may be injected from each of the plurality of internal fuel ports 231. The internal fuel port 231 may be formed on a side of one end of the internal fuel pipe 230. The fuel injection direction of the internal fuel port 231 may be a direction perpendicular to the axis of the internal fuel pipe 230. Figures 2 to 4 , eight internal fuel ports 231 may be formed at a side of one end of the internal fuel pipe 230 .

[0075] On the other hand, the side surface of the inner fuel pipe 230 may include a coupling portion for disposing the guide portion 250 , the igniter 291 , and the flame detection rod 292 .

[0076] There may be a plurality of external fuel pipes 240. Figures 2 to 4 The four external fuel pipes 240 may be radially arranged at the edge of the air supply pipe 201. However, the present invention is not limited thereto, and more than four external fuel pipes 240 or two to three external fuel pipes 240 may be arranged in the air supply pipe 201.

[0077] Each of the plurality of external fuel pipes 240 includes a plurality of external fuel ports 241 for generating an external flame. Fuel is ejected from each of the plurality of external fuel ports 241. For each of the plurality of external fuel pipes 240, the external fuel port 241 may be formed on a side of one end of the external fuel pipe 240, and the fuel ejection direction of the external fuel port 241 may be a direction perpendicular to the axis of the external fuel pipe 240. For example, two external fuel ports 241 are opposite and may be formed on a side of one end of each of the plurality of external fuel pipes 240, and when the number of the external fuel pipes 240 is four, there may be eight external fuel ports 241.

[0078] The guide part 250 is disposed between the inner fuel pipe 230 and the outer fuel pipe 240. That is, the inner fuel pipe 230 is disposed inside the guide part 250, and the outer fuel pipe 240 is disposed outside the guide part 250 (that is, between the guide part 250 and the air supply pipe 201).

[0079] The guide part 250 performs a function of conveying or supplying the air guided by the air supply pipe 201 to the inner fuel pipe 230. In addition, the guide part 250 is used to distinguish between a space where the inner fuel pipe 230 is arranged and a space where the outer fuel pipe 240 is arranged. Therefore, the inner flame and the outer flame can be generated in different spaces through the guide part 250.

[0080] The air guided into the guide portion 250 is supplied to one end of the internal fuel pipe 230, the fuel injected from the internal fuel port 231 meets and mixes with the air, and the mixed fuel / air is ignited to form an internal flame, ie, a diffusion flame.

[0081] Figure 5 FIG. 2 is a diagram showing a perspective view of a guide portion 250 according to an embodiment of the present invention.

[0082] Reference Figure 5 For example, the guide portion 250 may be in the shape of a hollow cylinder.

[0083] Air flows in from the other end of the guide part 250. One end of the guide part 250 is perforated, and an internal diffuser 251 (ie, a second diffuser) is disposed at the other end of the guide part 250. The internal diffuser 251 diffuses air into the inside of the guide part 250. The internal diffuser 251 may be ring-shaped as a whole.

[0084] According to an embodiment of the present invention, the size of one end of the guide portion 250 may be greater than the size of the other end of the guide portion 250. At this time, a step portion 252 connecting one end of the guide portion 250 and the other end of the guide portion 250 may be formed at the guide portion 250. The step portion 252 performs a function of supporting the cyclone 270 inside the guide portion 250.

[0085] According to an embodiment of the present invention, the internal diffuser 251 may be formed integrally with the guide portion 250, or may be manufactured separately from the guide portion 250 and disposed at the other end of the guide portion 250. The central portion of the internal diffuser 251 is perforated, and a plurality of second air holes 251a are formed at the edge portion. For example, the plurality of second air holes 251a may be radially formed at the edge portion.

[0086] The internal fuel pipe 230 may be placed or inserted into the central portion of the internal diffuser 251. The plurality of second air holes 251a may allow air to pass through and be delivered to the inside of the guide portion 250. That is, the plurality of second air holes 251a diffuse the air to the inside of the guide portion 250. The diameter of the central portion of the internal diffuser 251 may be slightly larger than the diameter of the internal fuel pipe 230. The plurality of second air holes 251a may all have the same size (diameter).

[0087] According to an embodiment of the present invention, the guide part 250 may be replaceable, and the size of the second air hole 251a of the replaced guide part 250 may be different from the size of the second air hole 251a of the guide part 250 before replacement. By replacing the guide part 250, the amount of air supplied to the inside of the guide part 250 may be adjusted.

[0088] According to an embodiment of the present invention, the inner flame may burn at an excessively rich concentration greater than a preset concentration based on the size of the second air hole 251a. That is, when the size of the second air hole 251a is less than a preset size, the amount of air passing through the second air hole 251a is reduced, and thus the inner flame may burn too richly.

[0089] According to an embodiment of the present invention, the sum of sizes of the plurality of second air holes 251 a may be less than 25% of the size of the other end of the guide portion 250 , in which case the internal flame may burn at an excessively rich concentration.

[0090] The external diffuser 260 (i.e., the first diffuser) is disposed inside the air supply pipe 201 and is disposed at one end of the guide portion 250 and one end of the external fuel pipe 240 to diffuse the air guided to the inside of the air supply pipe 201. The diffused air is delivered or supplied to the external fuel port 241 formed in the external fuel pipe 240.

[0091] The outer diffuser 260 may be annular in shape as a whole. The center of the outer diffuser 260 is perforated, and one end of the guide 250 may be placed or inserted into the center of the outer diffuser 260. A plurality of placement holes 261 for placing the outer fuel pipe 240 and a plurality of first air holes 262 for passing air may be formed at the edge of the outer diffuser 260.

[0092] For more details, see Figure 3 and Figure 4 , the plurality of external fuel pipes 240 may be placed inside each of the plurality of placement holes 261. Therefore, one end of the external fuel pipe 240 formed with the external fuel port 241 may be configured to protrude to the outside of the external diffuser 260, and the external fuel port 241 may be arranged outside the external diffuser 260. Here, the outside of the external diffuser 260 is a direction opposite to the direction in which the fuel chamber 220 is arranged relative to the external diffuser 260.

[0093] The plurality of first air holes 262 pass the air guided by the air supply pipe 201. That is, the plurality of first air holes 262 diffuse the air and provide it to the plurality of external fuel pipes 240. The plurality of first air holes 262 may be formed radially from the edge portion of the external diffuser 260. At this time, the plurality of first air holes 262 may be formed between the plurality of placement holes 261.

[0094] The fuel injected from the external fuel port 241 of each of the plurality of external fuel pipes 240 meets and mixes with the air passing through the plurality of first air holes 262, and the mixed gas of the air and the fuel is ignited to generate an external flame, i.e., a diffusion flame. That is, the external flame is generated outside one end of the guide portion 250 using the fuel injected from the external fuel port 241 and the air passing through the first air holes 262.

[0095] At this time, the external fuel port 241 is arranged on the side of the external fuel pipe 240, and the first air hole 262 is formed in the axial direction of the external fuel pipe 240. Therefore, the fuel injected from the external fuel port 241 and the air passing through the first air hole 262 intersect vertically and quickly form a mixed gas of air and fuel.

[0096] On the other hand, according to an embodiment of the present invention, the external flame may burn at a lean concentration below a preset concentration based on the size of the first air hole 262. That is, when the size of the first air hole 262 is greater than the preset size, the amount of air passing through the first air hole 262 increases, and the external flame may burn at a lean concentration.

[0097] The swirler 270 performs a function of promoting a combustion reaction of a mixed gas of air and fuel by mixing the air and fuel quickly and uniformly. The swirler 270 is disposed inside one end of the guide part 250 and can determine the shape of an internal flame.

[0098] At this time, as described above, the cyclone 270 inserted into the inside of one end of the guide part 250 is contacted and supported by the step part 252. Therefore, the cyclone 270 can be stably installed in the inside of the guide part 250.

[0099] The center of the swirler 270 is perforated, and one end of the internal fuel pipe 230 is mounted in the center of the swirler 270. A plurality of wings 271 for swirling air are formed at the edge of the swirler 270.

[0100] In more detail, one end of the internal fuel pipe 230 formed with the internal fuel port 231 is configured to protrude to the outside of the swirler 270. At this time, according to the shape of the wing portion 271, angular momentum is generated for the air flowing into the swirler 270, and thus the air rotates at one end of the guide portion 250 with the axis of the internal fuel pipe 230 as a reference. Therefore, the fuel injected from the internal fuel port 231 intersects the rotating air perpendicularly, and the fuel and the air can be mixed quickly. In addition, the mixed gas of the air and the fuel is ignited, so that an internal flame can be generated inside one end of the guide portion 250.

[0101] The position moving part 280 performs a function of changing the position of the external diffuser 260 in the air supply duct 201. That is, the position moving part 280 can move the external diffuser 260 to the front end and the rear end of the air supply duct 201.

[0102] In more detail, the position moving portion 280 includes a moving shaft 281 and a protrusion 282. The moving shaft 281 is formed to extend in the length direction. The protrusion 282 is formed at one end of the moving shaft 281. There may be at least one protrusion 282, and it may be combined with at least one connection hole 221c formed on the side of the first body portion 221a.

[0103] A portion of the moving shaft 281 is inserted into the through hole 211 formed between one end and the other end of the main fuel pipe 210 to be connected with the fuel chamber 220, namely, the first fuel chamber 221. At this time, when the external force of the user is applied to the moving shaft 281 (i.e., when the position moving part 280 is actuated), the position of the fuel chamber 220 is changed. That is, the first fuel chamber 221 moves inside one end of the main fuel pipe under the action of the external force applied to the moving shaft 281. The position of the external diffuser 260 can be changed as the position of the fuel chamber 220 is changed.

[0104] An igniter 291 performs a function of igniting the mixed gas, and the igniter 291 is coupled to a first retainer 293 , and the first retainer 293 coupled to the igniter 291 may be coupled to a coupling portion formed at the inner fuel pipe 230 .

[0105] The flame detection rod 292 changes the current rate by changing its own resistance value according to the intensity of the internal flame. The state of the internal flame can be grasped according to the changed current, thereby controlling the low nitrogen oxide burner. The flame detection rod 292 is combined with the second retainer 294, and the second retainer 294 combined with the flame detection rod 292 can be combined with the joint formed in the internal fuel pipe 230.

[0106] With reference to the above, the flame generation action of the low NOx burner is described as follows. Fuel is supplied to the internal fuel pipe 230 and the external fuel pipe 240 through the main fuel pipe 210 and the fuel chamber 220. Air is guided to the air supply pipe 201 and supplied to the inside and outside of the guide part 250. The fuel injected from the external fuel port 241 meets the air passing through the first air hole 262 formed in the external diffuser 260. The air passing through the second air hole 251a formed in the guide part 250 meets the fuel injected from the internal fuel port 231 through the swirler 270. The igniter 291 ignites the fuel injected from the external fuel port 241 based on the air flowing into the first air hole 262, thereby generating an external flame. Based on the generated external flame and the air flowing into the swirler 270, an internal flame is generated in the internal fuel port 231.

[0107] Hereinafter, some features of a low nitrogen oxide burner according to an embodiment of the present invention, namely, flame segmentation, mixing promotion, multi-stage combustion and internal recirculation, are described in detail.

[0108] 1. Flame segmentation

[0109] Figure 6 It is a diagram for explaining the concept of flame segmentation according to an embodiment of the present invention.

[0110] Reference Figure 6, an internal fuel pipe 230 and an external fuel pipe 240 are branched from the fuel chamber 220. At this time, the internal fuel pipe 230 generates an internal flame inside the low-nitrogen oxide burner, and the external fuel pipe 240 generates an external flame outside the low-nitrogen oxide burner. Therefore, the flames do not occur in one place, but occur separately. That is, flame segmentation corresponds to the separate generation of an internal flame based on the internal fuel pipe 230 and an external flame based on the external fuel pipe 240. In particular, the internal flame and the external flame can be accurately distinguished by the guide part 250. As a result, the temperature of the flame is reduced, and the amount of nitrogen oxides generated is reduced due to the reduction in the temperature of the flame.

[0111] 2. Mixing promotion

[0112] Figure 7 It is a diagram for explaining the concept of mixing promotion according to an embodiment of the present invention.

[0113] Reference Figure 7 In the conditions for generating the internal flame and the external flame, the injection direction of the fuel and the flow direction of the air are perpendicular to each other. That is, the internal fuel port 231 is formed on the side of the internal fuel pipe 230, and the external fuel port 241 is formed on the side of the external fuel pipe 240, and the air flows along the axial direction of the internal fuel pipe 230 and the external fuel pipe 240, so that the injected fuel meets the air perpendicularly. Therefore, a mixing promotion is formed to quickly mix the fuel and the air. In particular, the air rotates with the axis of the internal fuel pipe 230 as a reference through the swirler 270, so that the fuel and air used to generate the internal flame are mixed more quickly. Through rapid mixing, the generation of unburned gas is reduced, the temperature of the flame is reduced, and the generation of nitrogen oxides can be reduced.

[0114] 3. Multi-stage combustion

[0115] The inner flame is generated based on the air supplied from the second air hole 251a of the inner diffuser 251 disposed inside the guide part 250, and the outer flame is generated based on the air supplied from the first air hole 262 of the outer diffuser 260 disposed outside the guide part 250. At this time, by utilizing the sizes of the second air hole 251a and the first air hole 262 and the arrangement of the guide part 250, it is possible to control so that the inner flame burns too richly and the outer flame burns thinly. Therefore, a combustion reaction delay effect can be generated, so that most of the fuel can be burned, the temperature of the flame is reduced, and finally, the amount of nitrogen oxides generated can be reduced.

[0116] 4. Internal Recirculation

[0117] Figure 8 It is a diagram for explaining the concept of internal recirculation according to an embodiment of the present invention.

[0118] Reference Figures 2 to 4 , Figure 6 One end of the internal fuel pipe 230 is disposed farther than one end of the external fuel pipe 240 relative to one end of the air supply pipe 201. In addition, the size of the second air hole 251a of the internal diffuser 251 and the size of the first air hole 262 of the external diffuser 260 are different from each other.

[0119] Therefore, refer to Figure 8 Based on at least one of the difference between the air flow rate supplied to the inner fuel pipe 230 and the air flow rate supplied to the outer fuel pipe 240 and the layout of one end of the inner fuel pipe 230 and one end of the outer fuel pipe 240, the first internal recirculation 810 is generated in the outer space adjacent to the swirler 270. In particular, by arranging the outer diffuser 260 and the swirler 270 adjacent to each other (that is, the swirler 270 is arranged inside the outer diffuser 260), the first internal recirculation 810 occurs more significantly. Based on the first internal recirculation 810, the unburned gas generated when the inner flame is burned is used for the combustion of the outer flame, thereby reducing the temperature of the flame, and ultimately, the amount of nitrogen oxides generated can be reduced.

[0120] In addition, refer to Figure 8 The position of the external diffuser 260 in the air supply pipe 201 can be moved by the position moving part 280. At this time, the air flow rate passing through the first air hole 262 changes with the position change of the external diffuser 260, and a reverse flow is formed at one end of the combustion chamber 830 based on the changed flow rate, and the second internal recirculation 820 is generated according to the reverse flow. Here, one end of the combustion chamber 830 is arranged on the opposite side of the other end of the combustion chamber 830, and one end of the air supply pipe 201 is placed at the other end of the combustion chamber 830.

[0121] The temperature of the flame is reduced according to such first internal recirculation 820 and second internal recirculation 820, and eventually, the amount of nitrogen oxide generation can be reduced.

[0122] As described above, although the present invention is described based on specific matters such as specific constituent elements, limited embodiments and drawings, this is only provided to help the overall understanding of the present invention, and the present invention is not limited to the above embodiments. A person of ordinary skill in the art to which the present invention belongs can make various modifications and variations based on these descriptions. Therefore, the spirit of the present invention should not be limited by the described embodiments, and the attached claims and variations that are equivalent or equivalent to the claims should be considered to fall within the spirit of the present invention.

Claims

1. A low nitrogen oxide burner, characterized in that: include: a tube, one end of which is exposed to the combustion chamber and directs the air; an internal fuel pipe disposed inside the pipe and having an internal fuel port for generating an internal flame formed at one end of the internal fuel pipe; an external fuel pipe disposed inside the pipe and having an external fuel port formed at one end of the external fuel pipe for generating an external flame; a guide portion disposed between the inner fuel pipe and the outer fuel pipe and supplying the air to the inner fuel port; a first diffuser which is provided with one end of the guide portion and one end of the external fuel pipe and supplies the air to the external fuel port; as well as A swirler is disposed inside one end of the guide portion and one end of the inner fuel pipe is arranged at the center of the swirler.

2. The low nitrogen oxide burner according to claim 1, characterized in that: The internal fuel port is formed on a side surface of one end of the internal fuel pipe. One end of the internal fuel pipe formed with the internal fuel port is configured to protrude toward the outside of the swirler, The air flowing into the swirler through the guide portion rotates at one end of the guide portion with the axis of the internal fuel pipe as a reference, and the fuel injected from the internal fuel port intersects the rotating air perpendicularly. The inner flame is generated inside the one end of the guide portion by the fuel injected from the inner fuel port and the rotating air.

3. The low nitrogen oxide burner according to claim 1, characterized in that: A second diffuser is disposed at the other end of the guide portion. The center portion of the second diffuser is perforated, and a plurality of second air holes are formed at the edge portion of the second diffuser. The inner fuel pipe is disposed at a center portion of the second diffuser, and the air passes through a plurality of the second air holes.

4. The low nitrogen oxide burner according to claim 1, characterized in that: The central portion of the first diffuser is perforated, and one end of the guide portion is disposed at the central portion of the first diffuser. A placement hole for placing the external fuel pipe and a plurality of first air holes for allowing the air to pass therethrough are formed at an edge portion of the first diffuser.

5. The low nitrogen oxide burner according to claim 4, characterized in that: The external fuel port is formed on a side surface of one end of the external fuel pipe. One end of the external fuel pipe formed with the external fuel port is configured to protrude from the first diffuser, The fuel injected from the external fuel port intersects the air passing through the first air hole perpendicularly. The external flame is generated outside the one end of the guide portion by the fuel injected from the external fuel port and the air passing through the first air hole.

6. The low nitrogen oxide burner according to claim 5, characterized in that: There are a plurality of external fuel pipes, the plurality of external fuel pipes are radially arranged inside the pipe, and at least one external fuel port is formed on a side surface of one end of each of the plurality of external fuel pipes. There are a plurality of the installation holes, and a plurality of the external fuel pipes are installed inside each of the plurality of the installation holes. The plurality of first air holes are radially formed at an edge of the first diffuser.

7. The low nitrogen oxide burner according to claim 1, characterized in that: One end of the inner fuel pipe is disposed farther than one end of the outer fuel pipe, based on one end of the pipe, generating a first internal recirculation in an external space adjacent to the cyclone based on any one of a flow rate difference between air supplied to the inner fuel pipe and air supplied to the outer fuel pipe and a layout of one end of the inner fuel pipe and one end of the outer fuel pipe, Based on the first internal recirculation, unburned gas generated during the combustion of the inner flame is used in the combustion of the outer flame.

8. The low nitrogen oxide burner according to claim 4, characterized in that: further comprising a position moving portion for changing the position of the first diffuser in the tube, The flow rate of the air passing through the first air hole changes according to the position of the first diffuser, and a reverse flow is generated at one end of the combustion chamber based on the changed flow rate, and a second internal recirculation is generated along with the reverse flow. One end of the combustion chamber is arranged on the opposite side of the other end of the combustion chamber, and one end of the tube is placed on the other end of the combustion chamber.

9. The low nitrogen oxide burner according to claim 8, characterized in that: Also includes: a main fuel pipe, which supplies the fuel and is at least partially disposed inside the pipe; as well as A fuel chamber is arranged inside the pipe, the internal fuel pipe and the external fuel pipe are branched from one end of the fuel chamber, and the other end of the fuel chamber is connected to one end of the main fuel pipe. A through hole is formed between one end and the other end of the main fuel pipe, a part of the position moving part is inserted into the through hole to be connected to the fuel chamber, the position of the fuel chamber changes according to the action of the position moving part, and the position of the first diffuser changes with the change of the position of the fuel chamber.

10. A low nitrogen oxide burner, characterized in that: include: a tube, one end of which is exposed to the combustion chamber and directs the air; an internal fuel pipe disposed inside the pipe and having an internal fuel port for generating an internal flame formed at one end of the internal fuel pipe; an external fuel pipe disposed inside the pipe and having an external fuel port formed at one end of the external fuel pipe for generating an external flame; a guide portion disposed between the inner fuel pipe and the outer fuel pipe and formed with a plurality of second air holes for supplying the air to the inner fuel pipe; as well as a diffuser, on which the external fuel pipe is mounted and on which a plurality of first air holes for supplying the air to the external fuel pipe are formed, Based on the sizes of the plurality of second air holes and the sizes of the plurality of first air holes, the inner flame is burnt at an excessively rich concentration greater than a preset concentration, and the outer flame is burnt at a lean concentration less than a preset concentration.

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