A high-power low-nitrogen burner

Abstract

The present invention discloses a high-power low-nitrogen burner, comprising a volute, a peripheral air duct, a central air duct, a mixed combustion section, a peripheral gas injection device and a central gas injection device; the volute is used to connect with the air outlet of the fan to form a swirl air flow; the volute, the peripheral air duct and the mixed combustion section are connected in sequence to form a peripheral cavity; the central air duct is located in the peripheral cavity, and one end of the central air duct is connected to the inner cavity of the volute, and the other end extends to the mixed combustion section; the peripheral gas injection device is located in the peripheral air duct, and injects gas toward the mixed combustion section; the central gas injection device is arranged in the central air duct, and injects gas toward the mixed combustion section. The above-mentioned high-power low-nitrogen burner can solve the problems of poor mixing effect of the current thick-thin type burner, resulting in low combustion efficiency and high use cost due to unreasonable air duct setting.

Description

Technical Field

[0001] The invention relates to the technical field of burner design, and in particular to a high-power low-nitrogen burner. Background Art

[0002] A burner is a device for mixing fuel and air in a certain ratio for combustion. The combustion efficiency, manufacturing cost, equipment volume, and use cost of a burner are important indicators of its excellent performance. According to the combustion method, burners can be divided into many types. Rich-lean combustion type burners are one of them. The rich-lean combustion technology used by rich-lean combustion type burners is a combustion technology that can reduce NOx. This technology artificially divides the entire combustion process into several stages with different gas and air ratios, so that the combustion of the gas is completed in three stages: too rich gas, too thin gas, and burnout, thereby achieving the purpose of suppressing the generation of harmful NOx during the combustion process.

[0003] The current thick-thin burner has a poor mixing effect of gas and air during operation or cannot meet the reasonable coordination under different working conditions, which leads to insufficient combustion of fuel and low combustion efficiency. At the same time, due to the unreasonable setting of the air duct, the current thick-thin burner has a large pressure loss, which will increase the power of the fan and increase the production and use costs. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the current rich-lean type burner has a poor mixing effect, resulting in low combustion efficiency and high use cost due to unreasonable air duct settings.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0006] A high-power low-nitrogen burner comprises a volute, a peripheral air duct, a central air duct, a mixed combustion section, a peripheral gas injection device and a central gas injection device; wherein:

[0007] The volute is used to connect with the air outlet of the fan to form a swirling air flow;

[0008] The volute, the peripheral air duct and the mixed combustion section are sequentially connected to form a peripheral cavity;

[0009] The central air duct is located in the peripheral cavity, and one end of the central air duct is connected to the inner cavity of the volute, and the other end extends to the mixing and combustion section;

[0010] The peripheral gas injection device is located in the peripheral air duct and injects gas toward the mixed combustion section;

[0011] The central gas injection device is arranged in the central air duct and injects gas toward the mixed combustion section.

[0012] Furthermore, in the above-mentioned high-power low-nitrogen burner, the central air duct includes a first tapered section and a first equal-diameter section; the first tapered section is located in the volute, and the end with a smaller cross-sectional area of ​​the first tapered section is connected to the first equal-diameter section, and the first equal-diameter section extends from the volute to the mixed combustion section.

[0013] Furthermore, in the above-mentioned high-power low-nitrogen burner, the first necked section and the first equal-diameter section are coaxially distributed, and both are coaxially arranged with the peripheral cavity.

[0014] Furthermore, in the above-mentioned high-power low-nitrogen burner, the central gas injection device includes a central gas pipe, a central gas nozzle and a central swirler; the central gas pipe is coaxially arranged with the central air duct, and the central gas nozzle is arranged at the end of the central gas pipe; the central swirler is fixed to the central gas pipe for fixing one end of the central gas nozzle.

[0015] Furthermore, in the above-mentioned high-power low-nitrogen burner, the peripheral gas injection device comprises:

[0016] a combustion chamber fixed outside the peripheral air duct; and,

[0017] One end is communicated with the gas chamber, and the other end is introduced into the peripheral air duct, and multiple branch pipes spray gas to the mixed combustion section.

[0018] Furthermore, in the above-mentioned high-power low-nitrogen burner, the plurality of branch pipes extend in a direction parallel to the axis of the peripheral cavity.

[0019] Furthermore, in the above-mentioned high-power low-nitrogen burner, the plurality of branch pipes are provided with nozzles, and the nozzles are distributed in pairs, and the plurality of pairs of nozzles include at least a first pair of nozzles and a second pair of nozzles, the first pair of nozzles are multi-hole nozzles, and the second pair of nozzles are single-hole nozzles, and the single-hole nozzles spray in a direction parallel to the axis of the outer cavity.

[0020] Furthermore, in the above-mentioned high-power low-nitrogen burner, the peripheral air duct includes a second tapered section and a second equal-diameter section; the end of the second tapered section with a larger cross-sectional area is connected to the inner cavity of the volute, one end of the second equal-diameter section is connected to the end of the second tapered section with a smaller cross-sectional area, and the other end is connected to the mixed combustion section.

[0021] Furthermore, in the above-mentioned high-power low-nitrogen burner, a damper is arranged in the volute, and the damper is arranged at the position where the volute is connected with the peripheral air duct, for controlling the amount of air flowing into the peripheral air duct.

[0022] Furthermore, in the above-mentioned high-power low-nitrogen burner, the damper is driven by a transmission mechanism, and the transmission mechanism is located in the volute.

[0023] The beneficial effects of the present invention are:

[0024] In the high-power low-nitrogen burner provided by the present invention, the volute divides the formed swirl air flow into two streams, and enters the central air duct and the peripheral air duct respectively. The peripheral gas injection device and the central gas injection device can inject gas into the mixed gas section. This jet gas and swirl air mixing have a good mixing effect and can improve the combustion efficiency. At the same time, the high-power low-nitrogen burner provided by the present invention adopts the central air duct and the peripheral air duct arranged inside and outside to supply air at the same time. At the same time, a central gas injection device is arranged in the central channel, and a peripheral gas injection device is arranged in the peripheral air duct. The above-mentioned graded air supply and graded gas supply method have good adjustment flexibility, and thus can better adjust the ratio of gas and air of the rich and thin combustion burner under different working conditions. At the same time, through graded distribution, an oxygen-poor area and an oxygen-rich area are formed. The reactants in the oxygen-poor area will reduce the nitrogen oxides generated in the oxygen-rich area, thereby achieving a better combustion effect.

[0025] Experiments have proved that the high-power low-nitrogen burner provided by the present invention can achieve better mixing and combustion effects without a swirler. Not using a swirler can reduce the pressure loss of the rich-lean type burner itself, and will not lead to an increase in the power of the fan connected to the volute, thereby not increasing the production and use costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a high-power low-nitrogen burner provided in an embodiment of the present invention;

[0027] Figure 2 for Figure 1 Rear view of

[0028] Figure 3 for Figure 1 Right view of;

[0029] Figure 4 for Figure 1 Left view of

[0030] Figure 5 for Figure 4 Schematic diagram of the interior from the perspective shown;

[0031] Figure 6 A schematic diagram of the internal structure of a high-power low-nitrogen burner provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention discloses a high-power low-nitrogen burner, and those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It should be particularly pointed out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention, and relevant personnel can obviously modify or appropriately change and combine the contents described herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0033] In the present invention, unless otherwise specified, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art.

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific embodiments.

[0035] Please refer to Figure 1-6 An embodiment of the present invention provides a high-power low-nitrogen burner, which includes a volute 1, a peripheral air duct 2, a central air duct 3, a mixed combustion section 4, a peripheral gas injection device 5 and a central gas injection device 6.

[0036] The volute 1 is the air inlet part of the high-power low-nitrogen burner, and is usually connected to the air outlet of the fan to form a swirl air flow. Specifically, the air outlet of the fan extends in the tangent direction of the volute 1.

[0037] The mixing and combustion section 4 is a part where the fuel gas and air are mixed and burned. The volute 1, the peripheral air duct 2 and the mixing and combustion section 4 are connected in sequence to form the peripheral cavity of the high-power low-nitrogen burner.

[0038] The central air duct 3 is located in the peripheral cavity, one end of the central air duct 3 is connected to the inner cavity of the volute 1, and the other end extends to the mixing combustion section 4. The air in the volute 1 can enter the central air duct 3 to realize air supply from the middle of the peripheral cavity.

[0039] The peripheral air duct 2 and the central air duct 3 are arranged outside and inside. The peripheral air duct 2 is also connected to the inner cavity of the volute 1 for supplying air at the periphery, and the central air duct 3 is used to supply air at the center. After the swirl air flow enters the inner cavity of the volute 1, a part of it enters the peripheral air duct 2, and the other part enters the central air duct 3. Please refer to Figure 3 and 6 The central air duct 3 can be fixedly connected to the inner wall of the peripheral air duct 2 through a fixing rod 7.

[0040] The peripheral gas injection device 5 is located in the peripheral air duct 2 and injects gas toward the mixed combustion section 4. The central gas injection device 6 is disposed in the central air duct 3 and injects gas toward the mixed combustion section 4.

[0041] In the high-power low-nitrogen burner provided by the embodiment of the present invention, the volute 1 divides the formed swirl air flow into two streams, and enters the central air duct 3 and the peripheral air duct 2 respectively. The peripheral gas injection device 5 and the central gas injection device 6 can inject gas into the mixed gas section 4. This jet gas and swirl air mixing have a good mixing effect and can improve the combustion efficiency. At the same time, the high-power low-nitrogen burner provided in this embodiment adopts the central air duct 3 and the peripheral air duct 2 arranged inside and outside to supply air at the same time. At the same time, the central channel 3 is provided with a central gas injection device 6, and the peripheral gas injection device 5 is provided in the peripheral air duct 2. The above-mentioned graded air supply and graded gas supply method have good adjustment flexibility, and thus can better adjust the gas and air ratio of the rich and thin combustion burner under different working conditions. At the same time, through graded distribution, the oxygen-poor area and the oxygen-rich area are formed. The reactants in the oxygen-poor area will reduce the nitrogen oxides generated in the oxygen-rich area, thereby achieving a better combustion effect.

[0042] Experiments have proved that the high-power low-nitrogen burner provided in this embodiment can achieve better mixing and combustion effects without a swirler. Not using a swirler can reduce the pressure loss of the rich-lean type burner itself, and will not lead to an increase in the power of the fan connected to the volute 1, and thus will not increase the production and use costs.

[0043] The high-power low-nitrogen burner provided in this embodiment can adjust the gas and air through the central air duct 3 and the peripheral air duct 2 to achieve a larger adjustment ratio, thereby enabling the high-power low-nitrogen burner to be at more working points, meet more working conditions, and adapt to rapid load changes of equipment such as boilers.

[0044] Please refer to Figure 1 , 2 6. In the present embodiment, the central air duct 3 includes a first constricted section 31 and a first equal diameter section 32. The first constricted section 31 is located in the volute 1, and the end of the first constricted section 31 with a smaller cross-sectional area is connected to the first equal diameter section 32, and the first equal diameter section 32 extends from the volute 1 to the mixing and combustion section 4. In this case, after the air enters the central air duct 3, the first constricted section 31 can accelerate the air, thereby better maintaining the swirl air flow, and better preparing for subsequent mixing. Specifically, the first constricted section 31 is coaxially distributed with the first equal diameter section 32, and is coaxially arranged with the peripheral cavity, so as to achieve a better central air supply effect.

[0045] Please refer again Figure 6The central gas injection device 6 may include a central gas pipe 61, a central gas nozzle 62 and a central swirler 63. The central gas pipe 61 is coaxially arranged with the central air duct 3, and the central gas nozzle 62 is arranged at the end of the central gas pipe 61. The central swirler 63 is fixed to one end of the central gas pipe 61 for fixing the central gas nozzle 62. The function of the central swirler 63 is to maintain the air entering the central gas pipe 61 in a swirling state, which will not cause a large pressure loss in the burner. Therefore, on the whole, it can not only play a good mixing role, but also will not increase the power of the fan, nor increase the production and use costs of the burner.

[0046] Please refer to Figure 6 In the high-power low-nitrogen burner provided in this embodiment, the central gas injection device 6 may include a central gas pipe 61, a central gas nozzle 62 and a central swirler 63, which are coaxially arranged. The central gas pipe 61 is coaxially arranged with the central air duct 3, and the central gas nozzle 62 is arranged at the end of the central gas pipe 61. The central swirler 63 is fixed to one end of the central gas pipe 61 for fixing the central gas nozzle 62. The function of the central swirler 63 is only to maintain the air flow in a swirling state, and the central swirler 63 is located inside the central air duct 3, so relative to the entire high-power low-nitrogen burner, the power of the fan will not be increased.

[0047] Please refer again Figure 6 The peripheral gas injection device 5 may include a gas chamber 51 and a plurality of branch pipes 52. The gas chamber 51 is fixed to the outside of the peripheral air duct 2, one end of the plurality of branch pipes 52 is connected to the gas chamber 51, and the other end is introduced into the peripheral air duct 2, for spraying gas to the mixed combustion section 4. The plurality of branch pipes 52 spray gas at multiple points into the mixed combustion section 4, which can improve the mixing effect. Preferably, the plurality of branch pipes 52 are evenly distributed along the outside of the central gas pipe 61. Nozzles may be arranged in the injection sections of the plurality of branch pipes 52. The plurality of branch pipes 52 may all extend in a direction parallel to the axis of the peripheral cavity.

[0048] Please refer to Figure 3 The multiple branch pipes 52 are all provided with nozzles, and the nozzles can be distributed in pairs. The multiple pairs of nozzles include at least a first pair of nozzles and a second pair of nozzles. The first pair of nozzles are multi-hole nozzles, and the second pair of nozzles are single-hole nozzles, and the single-hole nozzles spray in a direction parallel to the axis of the peripheral cavity.

[0049] Please refer to Figure 1 , 26, the peripheral air duct 2 may include a second constricted section 21 and a second equal diameter section 22; the end of the second constricted section 21 with a larger cross-sectional area is communicated with the inner cavity of the volute 1, one end of the second equal diameter section 22 is butted with the end of the second constricted section 21 with a smaller cross-sectional area, and the other end is connected to the mixing combustion section 4. Similarly, the second constricted section 21 can accelerate the air flow while better maintaining the swirl state.

[0050] In order to better adjust the amount of air entering the peripheral air duct 2, a damper 11 may be provided in the volute 1. The damper 11 is provided at the portion where the volute 1 is connected to the peripheral air duct 2, and is used to control the amount of air flowing into the peripheral air duct 2. Specifically, in this embodiment, the damper 11 is driven by a transmission mechanism, and the transmission mechanism is located in the volute 1. The transmission mechanism is provided in the volute 1, which can reduce human damage and also avoid harm to the operator.

[0051] The structure of the high-power low-nitrogen burner provided in this embodiment can be divided into multiple components that can be detachably connected, which is convenient for the replacement and maintenance of components and reduces the labor and mechanical costs of installation. The peripheral components of the high-power low-nitrogen burner can be set with multiple installation positions to facilitate the high-power low-nitrogen burner to adapt to different external installation environments. The high-power low-nitrogen burner can be provided with observation holes and installation holes to facilitate observation of working conditions and connections.

[0052] The high-temperature parts of the high-power low-nitrogen burner provided in this embodiment, such as the mixed combustion zone, can be made of high-temperature resistant materials, and the mixed combustion zone can be connected to other parts with threads or pins to facilitate disassembly and replacement, thereby reducing the replacement cost of parts.

[0053] The high-power low-nitrogen burner provided in this embodiment can adjust the amount of gas and air in the peripheral air duct 2 and the central air duct 3 at the same time, thereby changing the position of the thick and thin areas, that is, the ratio, and thus reducing the generation of nitrogen oxides.

[0054] It should be noted that in this application, the high-power low-nitrogen burner can reduce the generation of nitrogen oxides during the combustion process, thereby achieving a low-nitrogen effect, and the emission of nitrogen oxides can reach 60mg / m 3 (@3% O2). High power means the burner power is greater than 5.6MW.

[0055] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-power low-nitrogen burner, characterized in that: It includes a volute, a peripheral air duct, a central air duct, a mixed combustion section, a peripheral gas injection device and a central gas injection device; wherein: The volute is used to connect with the air outlet of the fan to form a swirling air flow; The volute, the peripheral air duct and the mixed combustion section are sequentially connected to form a peripheral cavity; The central air duct is located in the peripheral cavity, and one end of the central air duct is connected to the inner cavity of the volute, and the other end extends to the mixing and combustion section; The peripheral gas injection device is located in the peripheral air duct and injects gas toward the mixed combustion section; The central gas injection device is arranged in the central air duct and injects gas toward the mixed combustion section; The central air duct includes a first constricted section and a first equal-diameter section; the first constricted section is located in the volute, and an end of the first constricted section with a smaller cross-sectional area is connected to the first equal-diameter section, and the first equal-diameter section extends from the volute to the mixing and combustion section; The peripheral gas injection device comprises: a combustion chamber fixed outside the peripheral air duct; and, One end of the branch pipe is connected to the gas chamber, the other end of the branch pipe is introduced into the peripheral air duct, and multiple branch pipes spray gas to the mixed combustion section; The plurality of branch pipes are provided with nozzles, the nozzles are distributed in pairs, the plurality of pairs of nozzles at least include a first pair of nozzles and a second pair of nozzles, the first pair of nozzles are multi-hole nozzles, the second pair of nozzles are single-hole nozzles, and the single-hole nozzles spray in a direction parallel to the axis of the peripheral cavity; The peripheral air duct includes a second tapered section and a second equal-diameter section; the end of the second tapered section with a larger cross-sectional area is connected to the inner cavity of the volute, one end of the second equal-diameter section is connected to the end of the second tapered section with a smaller cross-sectional area, and the other end is connected to the mixed combustion section.

2. The high-power low-nitrogen burner according to claim 1, characterized in that: The first necking section and the first equal-diameter section are coaxially distributed, and are both coaxially arranged with the peripheral cavity.

3. The high-power low-nitrogen burner according to claim 1, characterized in that: The central gas injection device includes a central gas pipe, a central gas nozzle and a central swirler; the central gas pipe is coaxially arranged with the central air duct, and the central gas nozzle is arranged at the end of the central gas pipe; the central swirler is fixed to the central gas pipe for fixing one end of the central gas nozzle.

4. The high-power low-nitrogen burner according to claim 1, characterized in that: The plurality of branch pipes extend along a direction parallel to the axis of the peripheral cavity.

5. The high-power low-nitrogen burner according to claim 1, characterized in that: A damper is arranged in the volute, and the damper is arranged at the position where the volute is connected with the peripheral air duct, and is used to control the amount of air flowing into the peripheral air duct.

6. The high-power low-nitrogen burner according to claim 5, characterized in that: The damper is driven by a transmission mechanism, and the transmission mechanism is located in the volute.

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