A fully premixed burner and its primary heat exchanger

Abstract

The application discloses a full premix burner and a main heat exchanger thereof, which comprises a mounting base, a distribution cylinder and a combustion cylinder; the mounting base is provided with an air inlet hole communicated with the distribution cylinder, and the distribution cylinder is provided with a plurality of air distribution holes; the combustion cylinder is mounted on the outer side of the distribution cylinder, and the combustion cylinder and the distribution cylinder have a ventilation gap; the combustion cylinder is provided with a plurality of combustion holes communicated with the air distribution holes through the ventilation gap. The full premix burner is provided with the distribution cylinder and the combustion cylinder, the premixed combustion gas is first distributed in the distribution cylinder, then uniformly distributed through the ventilation gap, and then combusted through the combustion cylinder. Through reasonable distribution of the air distribution holes and the combustion holes, the stability of flame combustion and the combustion efficiency are improved, the service life of the burner is longer, and the cost is lower.

Description

Technical Field

[0001] This invention relates to the field of burner technology, and more specifically to a fully premixed burner and its main heat exchanger. Background Technology

[0002] The operating principle of the fully premixed condensing furnace is as follows: the gas enters the premixing chamber through the gas control proportional valve, and the air enters the premixing chamber inside the furnace through the outer shaft of the balanced chimney. After the gas and air are mixed in the premixing chamber, they enter the fan. The fan sends the gas-air mixture to the combustion chamber of the main heat exchanger for combustion by rotation. After combustion, high-temperature flue gas is generated, and heat exchange is completed in the main heat exchanger. The heating channel delivers the heat to the room, and the flue gas is discharged to the outside through the inner shaft of the balanced chimney.

[0003] The fully premixed burner is installed inside the main heat exchanger, ensuring that the gas and air are fully premixed in a specific ratio before combustion. The combustion speed of the fully premixed burner is not limited by mixing time or space, and it boasts advantages such as fast combustion speed, instantaneous combustion of the mixed gas after leaving the burner orifice, complete combustion, low nitrogen oxide emissions, and low noise. It has gained increasing use, especially in condensing water heaters and condensing boilers. However, the use of fully premixed condensing boilers in my country started relatively late. Currently, the mainstream boiler market still uses conventional gas-fired boilers without full premixing technology, indicating that fully premixed burner technology is not yet mature enough.

[0004] Existing burners have the following drawbacks: 1. The existing burner structure is unreasonable. When there is insufficient gas or the burner orifice is blocked, it is easy to cause unstable flame combustion, backfire and flameout, resulting in incomplete combustion, affecting the stable operation of the burner, and also causing deflagration and noise, or even damaging the burner; 2. The existing main heat exchanger has incomplete combustion during the combustion process, producing a large number of carbon solid particles. After long-term use, it causes blockage of the burner orifice, reduces thermal efficiency, and further damages the burner, reducing its service life; 3. The fully premixed burners on the market use metal fiber materials, which have complex processes and high costs. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a fully premixed burner that solves the aforementioned traditional problems. It first uniformly distributes the premixed combustion gas inside the burner before combustion. Through a reasonable arrangement of combustion holes, it improves the stability and efficiency of flame combustion, resulting in a longer service life and lower cost for the burner.

[0006] The second objective of this invention is to provide a main heat exchanger employing this fully premixed burner.

[0007] One of the objectives of this invention is achieved through the following technical solution:

[0008] A fully premixed burner includes a mounting base, a distribution cylinder mounted on the mounting base, and a combustion cylinder; the mounting base has an air inlet communicating with the distribution cylinder, and the distribution cylinder has a plurality of air distribution holes; the combustion cylinder is mounted on the outside of the distribution cylinder, and there is a ventilation gap between the combustion cylinder and the distribution cylinder; the combustion cylinder has a plurality of combustion holes, and the combustion holes communicate with the air distribution holes through the ventilation gap.

[0009] Furthermore, the air distribution holes include a first air distribution hole and a second air distribution hole. Each of the first air distribution holes is evenly distributed to form a first distribution hole group, and each of the second air distribution holes is evenly distributed to form a second distribution hole group. The first distribution hole group and the second distribution hole group are arranged alternately.

[0010] Furthermore, both the first and second air distribution holes are round holes formed by stamping.

[0011] Furthermore, the diameter of the first air distribution hole is smaller than the diameter of the second air distribution hole.

[0012] Furthermore, the distance between the first air distribution hole and the second air distribution hole in the lateral direction is equal to the distance between the first air distribution hole and the second air distribution hole in the longitudinal direction.

[0013] Furthermore, the combustion holes include multiple main flame holes, flame stabilizing holes, and backfire prevention holes; each of the main flame holes is evenly arranged to form multiple rows of longitudinal main flame hole groups, and each of the longitudinal main flame hole groups forms multiple transverse main flame groups in units of four groups; each of the flame stabilizing holes is evenly arranged to form multiple rows of transverse flame stabilizing hole groups, and the transverse flame stabilizing hole groups are disposed between two groups of transverse main flame groups, and each of the flame stabilizing holes is combined in pairs to form multiple longitudinally evenly distributed longitudinal flame stabilizing hole groups; the backfire prevention holes are disposed between two groups of longitudinal flame stabilizing hole groups.

[0014] Furthermore, the main flame hole is a round hole; the flame stabilizing hole and the backfire prevention hole are both elongated.

[0015] Furthermore, the mounting base includes a base body, a first mounting portion and a second mounting portion extending from the base body, wherein the outer diameter of the first mounting portion is larger than the outer diameter of the second mounting portion, and the first mounting portion and the second mounting portion are bent sequentially on the base body to form a stepped structure.

[0016] Furthermore, the fully premixed burner also includes a sealing disc for sealing the top of the distribution cylinder and the combustion cylinder. The sealing disc includes a disc body, a first sealing flange and a second sealing flange extending from the disc body. The outer diameter of the first sealing flange is smaller than the outer diameter of the second sealing flange. The first sealing flange and the second sealing flange are bent sequentially on the disc body to form a stepped structure. The disc body is embedded in the distribution cylinder. The outer wall of the first sealing flange abuts against the inner wall of the distribution cylinder, and the outer wall of the second sealing flange abuts against the inner wall of the combustion cylinder.

[0017] The second objective of this invention is achieved by the following technical solution:

[0018] A main heat exchanger comprising the fully premixed burner described above.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] The fully premixed burner of the present invention distributes the premixed combustion gas in the distribution cylinder first by setting up a distribution cylinder and a combustion cylinder, and then forms a uniform distribution through the ventilation gap, and then burns it through the combustion cylinder. Through the reasonable arrangement of gas distribution holes and combustion holes, the stability of flame combustion and combustion efficiency are improved, resulting in a longer service life and lower cost of the burner.

[0021] The fully premixed burner of the present invention, through the cooperation of the flame stabilization port, the backfire prevention port and the main flame port, enables the fully premixed burner to maintain stable flame operation in various states, making combustion more complete and the combustion efficiency higher. It can solve the problems of unstable combustion, backfire and flameout that exist in current fully premixed burners. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the main heat exchanger of the present invention;

[0023] Figure 2 for Figure 1 The diagram shows the internal structure of the main heat exchanger.

[0024] Figure 3 for Figure 2 The diagram shows the installation structure of the fully premixed burner on the main heat exchanger.

[0025] Figure 4 for Figure 3 The diagram shows a three-dimensional structure of a fully premixed burner.

[0026] Figure 5 for Figure 4 The exploded view of the fully premixed burner shown;

[0027] Figure 6 for Figure 4The side view of the fully premixed burner shown;

[0028] Figure 7 for Figure 6 The sectional view shown in the AA direction;

[0029] Figure 8 for Figure 5 The diagram shows the unfolded state of the distribution cylinder;

[0030] Figure 9 for Figure 8 The enlarged view at point B is shown below;

[0031] Figure 10 for Figure 5 The diagram shows the unfolded state of the combustion chamber;

[0032] Figure 11 for Figure 10 The enlarged view of point C shown.

[0033] In the diagram: 100, fully premixed burner; 90, premixing chamber; 80, fan; 70, mixed gas delivery channel; 60, stainless steel coil; 50, smoke collection chamber; 40, sealing disc; 41, disc body; 42, first sealing flange; 43, second sealing flange; 30, combustion cylinder; 31, main flame port; 32, flame stabilization port; 33, backfire prevention port; 34, first air guide zone; 35, second air guide zone; 20, distribution cylinder; 21, first gas distribution port; 22, second gas distribution port; 10, mounting base; 11, base body; 110, air inlet; 111, fixing hole; 12, first mounting part; 13, second mounting part. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In the description of this invention, it should be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" connected to another element, there are no intermediate elements.

[0037] Please see Figures 1 to 3 The main heat exchanger, which is a preferred embodiment of the present invention, is used to be installed in a fully premixed condensing furnace or hot water furnace to premix air and fuel gas, then combust them. The heat generated by the combustion heats the system water, raising its temperature, and finally discharges it through the flue.

[0038] Specifically, the main heat exchanger includes a premixing chamber 90, a fan 80, a mixed gas conveying channel 70, a fully premixed burner 100, a stainless steel coil 60, and a smoke collection chamber 50 arranged sequentially along the airflow direction. The premixing chamber 90 has an air inlet and a gas inlet, which draw air and gas into the premixing chamber 90 for mixing. The main heat exchanger is equipped with an ignition needle and a flame detection needle located on one side of the fully premixed burner 100. The ignition needle is used to ignite the mixed gas, and the flame detection needle is used to detect whether the flame is ignited or extinguished. There is a flue gas emission channel between the stainless steel coil 60 and the fully premixed burner 100, which is used for high-temperature flue gas to exchange heat with the stainless steel coil 60 before being centrally discharged into the smoke collection chamber 50. The working principle of the main heat exchanger is as follows: air and fuel gas are initially mixed in the premixing chamber 90, and the fan 80 delivers the mixed gas to the fully premixed burner 100 for uniform distribution. Then, it is ignited under the action of the ignition needle, and the heat is transferred to the cold water in the stainless steel coil 60. The flue gas after heat exchange is then collected in the smoke collection chamber 50 and discharged.

[0039] In one embodiment, please refer again Figures 3 to 11 The fully premixed burner 100 includes a mounting base 10, a distribution cylinder 20 mounted on the mounting base 10, and a combustion cylinder 30.

[0040] Please refer to the following: Figures 3-5 The mounting base 10 includes a base body 11, a first mounting portion 12 and a second mounting portion 13 extending from the base body 11 toward the distribution cylinder 20; the base body 11 is generally disc-shaped, and the base body 11 is provided with an air inlet 110 and fixing holes 111 arranged around the air inlet 110; the air inlet 110 extends longitudinally through the middle of the first mounting portion 12 and the middle of the second mounting portion 13, and is used to allow the mixed gas to flow into the fully premixed burner 100; there are four fixing holes 111, and the fixing holes 111 are evenly distributed so that the mounting base 10 can be fixed to the mixed gas inlet of the main heat exchanger by screws or bolts.

[0041] One end of the first mounting part 12 is connected to the base body 11, and the other end of the second mounting part 13 is connected to the second mounting part 13. The first mounting part 12 is used to mount the combustion cylinder 30, and the second mounting part 13 is used to mount the distribution cylinder 20. In one embodiment, such as Figure 7 As shown, the outer diameter of the first mounting part 12 is larger than the outer diameter of the second mounting part 13. The first mounting part 12 and the second mounting part 13 are bent sequentially on the seat body 11 to form a stepped structure, so that there is a ventilation gap between the distribution cylinder 20 and the combustion cylinder 30. In another embodiment, both the first mounting part 12 and the second mounting part 13 are circular, and the first mounting part 12 and the second mounting part 13 are concentric circles. Figure 3 As shown, after the mounting base 10 is fixedly installed on the mixed gas inlet of the main heat exchanger by screws or bolts, the top of the screws or bolts abuts against the combustion cylinder 30 to better fix the combustion cylinder 30. Optionally, after the distribution cylinder 20 and the combustion cylinder 30 are fixedly installed on the mounting base 10, they can be fixed or sealed by welding, such as spot welding or full welding.

[0042] Please refer to the following: Figure 8 and Figure 9 The distribution cylinder 20 is cylindrical and coaxially engages with the outer edge of the second mounting portion 13 of the mounting base 10, and communicates with the air inlet 110. The distribution cylinder 20 is provided with multiple air distribution holes for uniformly distributing the mixed gas. Specifically, the air distribution holes include multiple first air distribution holes 21 and second air distribution holes 22. Each first air distribution hole 21 is evenly distributed to form a first distribution hole group. The first distribution hole group can be formed by the first air distribution holes 21 being arranged horizontally or vertically. Each second air distribution hole 22 is evenly distributed to form a second distribution hole group. The second distribution hole group can be formed by the second air distribution holes 22 being arranged horizontally or vertically. The first air distribution holes 21 and the second air distribution holes 22 are air distribution holes of the same shape or different shapes, such as round holes, elongated holes, elliptical holes, square holes, etc., or a combination of two or more. In this embodiment, the first air distribution holes 21 and the second air distribution holes 22 are both round holes formed by stamping. Optionally, the diameter of the first air distribution hole 21 and the diameter of the second air distribution hole 22 may be the same or different circular holes. In one embodiment, the diameter of the first air distribution hole 21 is 1.2mm-2.8mm, and the diameter of the second air distribution hole 22 is 1.2mm-2.8mm. For example, the diameters of the first air distribution hole 21 and the second air distribution hole 22 are, but not limited to, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, 2.2mm, 2.4mm, 2.6mm, and 2.8mm. In this embodiment, the diameter of the first air distribution hole 21 is smaller than the diameter of the second air distribution hole 22.

[0043] For example Figure 8As shown, the unfolded state of the distribution cylinder 20 is a rectangular metal plate, such as stainless steel or pure copper, with a plate thickness of 0.7mm-1.5mm. The first and second distribution hole groups are alternately arranged in the horizontal and / or vertical directions. For example, in the vertical direction, the first distribution hole group, the second distribution hole group, the first distribution hole group, and the second distribution hole group are arranged sequentially from top to bottom; in the horizontal direction, the second distribution hole group, the first distribution hole group, the second distribution hole group, and the first distribution hole group are arranged sequentially from left to right, and so on in a cyclical manner. Preferably, the first and second distribution hole groups are alternately arranged in both the horizontal and vertical directions. In one embodiment, for example... Figure 9 As shown, the horizontal spacing b1 and the vertical spacing b2 of adjacent first air distribution holes 21 and second air distribution holes 22 may be the same or different. In this embodiment, the horizontal spacing b1 and the vertical spacing b2 of the first air distribution holes 21 and second air distribution holes 22 are the same, that is, b1 = b2. The range of b1 (or b2) is 3mm-8mm, for example, one of the spacings of 3mm, 4mm, 5mm, 6mm, 7mm, and 8mm. This ensures that the first air distribution holes 21 and second air distribution holes 22 with different diameters are evenly distributed horizontally and vertically. When the mixed gas enters the burner, under the action of the evenly distributed air holes in the distribution cylinder 20, the airflow velocity field is evenly propagated to the combustion cylinder 30, so as to ensure that the airflow velocity at each point is greater than the combustion velocity under the minimum load, so that the mixed gas burns more completely, the noise is lower, and the flame distribution is more uniform and stable. Preferably, the distribution cylinder 20 is made of stainless steel in one piece.

[0044] Please refer to the following: Figure 10 and Figure 11The combustion cylinder 30 is cylindrical and coaxially engages with the outer edge of the first mounting part 12 of the mounting base 10, i.e., it is installed on the outside of the distribution cylinder 20. The inner diameter of the combustion cylinder 30 is larger than the outer diameter of the distribution cylinder 20. The combustion cylinder 30 and the distribution cylinder 20 are concentric cylinders. The combustion cylinder 30 is provided with multiple combustion holes. The combustion cylinder 30 is connected to the gas distribution hole through the ventilation gap. It is used to burn the mixed gas distributed by the distribution cylinder 20 and can ensure the stability and efficiency of flame combustion. Specifically, the combustion holes include multiple main flame holes 31, flame stabilizing holes 32 and backfire prevention holes 33. In the longitudinal direction, the main burner holes 31 are evenly arranged to form multiple rows of longitudinal main burner hole groups. In the transverse direction, each longitudinal main burner hole group forms multiple transverse main burner groups in units of four, with gaps between each transverse main burner group. In one embodiment, the main burner hole 31 is, but is not limited to, a circular hole; it can also be an elliptical hole. In this embodiment, the main burner hole 31 is a circular hole. The purpose of designing the main burner hole 31 as a circular hole is to prevent backfire in the burner. Backfire occurs because when the velocity of the gas leaving the burner hole is less than the combustion velocity, the flame will retract into the burner hole, causing the mixed gas to burn and heat inside the burner, resulting in incomplete combustion and burner damage. Because the combustion velocity of the premixed burner is fast, an overly large main burner hole 31 can easily lead to backfire. Therefore, setting the main burner hole 31 as a small circular hole can prevent backfire in the burner, making combustion more complete and improving combustion efficiency. However, if the main burner hole 31 is too small, it can easily lead to flameout, resulting in unstable combustion and easy flameout. In one embodiment, the diameter of the main fire hole 31 is 0.5mm-0.9mm, such as 0.5mm, 0.6mm, 0.7mm, 0.8mm, or 0.9mm.

[0045] The flame stabilizing holes 32 are used to stabilize combustion and prevent flameout. Specifically, in the transverse direction, the flame stabilizing holes 32 are evenly arranged to form multiple rows of transverse flame stabilizing hole groups, which are located between two groups (four rows make up one group, a total of eight rows) of transverse main flame groups. In one embodiment, the flame stabilizing holes 32 are generally elongated. In the longitudinal direction, the flame stabilizing holes 32 are combined in pairs to form multiple longitudinally evenly distributed longitudinal flame stabilizing hole groups. It can be understood that each longitudinal flame stabilizing hole group consists of two flame stabilizing holes 32. In one embodiment, the diameter of the main flame hole 31 is greater than the width of the flame stabilizer hole 32 and less than the length of the flame stabilizer hole 32. Since the cross-sectional area of ​​a single flame stabilizer hole 32 is greater than the cross-sectional area of ​​a single main flame hole 31, in order to prevent local flameout that may occur when the burner is under full load and high fire, the flame stabilizer hole 32 is set between two sets of transverse main flame groups. Under high fire conditions, the airflow velocity of the flame stabilizer hole 32 is lower than that of the main flame hole 31. The flame stabilizer hole 32 can stabilize combustion and prevent flameout. In one embodiment, the width of the flame stabilizer hole 32 is 0.35mm-0.6mm and the length is 4mm-8mm.

[0046] To prevent backfire during low-load operation where the airflow velocity is low, the anti-backfire port 33 is positioned between two sets of longitudinal stabilizing ports. The anti-backfire port 33 is roughly elongated, with its length less than the length of the stabilizing port 32, and its width equal to the width of the stabilizing port 32. The diameter of the main flame port 31 is greater than the width of the anti-backfire port 33 but less than its length. Due to the smaller cross-sectional area of ​​the anti-backfire port 33, its airflow velocity is lower than that of the stabilizing port 32. With a higher flow rate, it can maintain more stable combustion under low flame conditions. Furthermore, the anti-backfire hole 33 is positioned between the two sets of longitudinal flame stabilizing holes, close to the flame stabilizing hole 32, preventing backfire from occurring in the flame stabilizing hole 32 under low load conditions. Through the cooperation of the flame stabilizing hole 32, the anti-backfire hole 33, and the main flame hole 31, the fully premixed burner 100 can maintain stable flame operation under various conditions, resulting in more complete combustion and higher combustion efficiency. This solves the problems of unstable combustion, backfire, and flameout that currently exist in fully premixed burners 100. In one embodiment, the length of the anti-backfire hole 33 is 0.3-0.4 times the length of the flame stabilizing hole 32. Optionally, the anti-backfire hole 33 is divided into a first anti-backfire hole 33 and a second anti-backfire hole 33 of the same size, arranged side-by-side.

[0047] For example Figure 11 As shown, the open state of the combustion cylinder 30 is a rectangular metal plate, such as stainless steel or pure copper. Preferably, the combustion cylinder 30 is made of stainless steel in one piece, with a plate thickness of 0.7mm-1.5mm. The length and width of the open state of the combustion cylinder 30 are greater than the length and width of the open state of the distribution cylinder 20. As shown in the unfolded state diagram, the area of ​​the main flame hole 31 on the combustion cylinder 30 is greater than the total area of ​​the flame stabilizing hole 32 and the backfire prevention hole 33 on the combustion cylinder 30. In another embodiment, the combustion... The combustion chamber 30 is also provided with a first air guide region 34 and a second air guide region 35 located at opposite ends. The first air guide region 34 is located near the mounting base 10, and the second air guide region 35 is located near the sealing plate 40. That is, the first air guide region 34 and the second air guide region 35 are located at opposite ends of the area where the main flame hole 31, the flame stabilizing hole 32, or the backfire prevention hole 33 are located, and are used to cooperate with the structure of the mounting base 10 to guide the mixed gas from the distribution cylinder 20 from both ends of the combustion chamber 30 to the middle of the combustion chamber 30. In one embodiment, the width c2 of the first air guide region 34 is greater than the width c1 of the second air guide region 35, so that the flame is away from the mounting base 10.

[0048] The aforementioned fully premixed burner 100, by setting up a distribution cylinder 20 and a combustion cylinder 30, first distributes the premixed combustion gas in the distribution cylinder 20, then forms a uniform distribution through the ventilation gap, and then burns it through the combustion cylinder 30. Through the reasonable arrangement of gas distribution holes and combustion holes, the stability of flame combustion and combustion efficiency are improved, resulting in a longer service life and lower cost for the burner.

[0049] The tops of the distribution cylinder 20 and the combustion cylinder 30 of the present invention can be individually welded with sealing structures to form a top seal, or integrally formed with a sealing top, or other sealing devices can be provided. See also Figure 7 As shown, the fully premixed burner 100 also includes a sealing disc 40, which is used to seal the top of the distribution cylinder 20 and the combustion cylinder 30 respectively, so that the mixed gas cannot flow out of the combustion cylinder 30 through the top of the distribution cylinder 20, or flow back into the distribution cylinder 20 from the combustion cylinder 30, or flow out directly from the top of the combustion cylinder 30. Specifically, the sealing disc 40 includes a disc body 41, a first sealing flange 42 and a second sealing flange 43 extending from the disc body 41 in the direction away from the distribution cylinder 20. The disc body 41 is generally disc-shaped. The outer diameter of the first sealing flange 42 is smaller than the outer diameter of the second sealing flange 43. The first sealing flange 42 and the second sealing flange 43 are bent sequentially on the disc body 41 to form a stepped structure. The disc body 41 is embedded in the distribution cylinder 20. The outer wall of the first sealing flange 42 abuts against the inner wall of the distribution cylinder 20, and the outer wall of the second sealing flange 43 abuts against the inner wall of the combustion cylinder 30 to form a stepped sealing structure. Optionally, after the distribution cylinder 20 and the combustion cylinder 30 are fixedly installed on the sealing disc 40, they can be fixed or sealed by welding, such as spot welding or full welding.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A fully premixed burner, characterized in that, The system includes a mounting base, a distribution cylinder mounted on the mounting base, and a combustion cylinder. The mounting base has an air inlet communicating with the distribution cylinder, and the distribution cylinder has multiple air distribution holes. The combustion cylinder is mounted outside the distribution cylinder, and a ventilation gap exists between the combustion cylinder and the distribution cylinder. The combustion cylinder has multiple combustion holes communicating with the air distribution holes through the ventilation gap. Each air distribution hole includes a first air distribution hole and a second air distribution hole. The first air distribution holes are evenly distributed to form a first distribution hole group, and the second air distribution holes are evenly distributed to form a second distribution hole group. The first and second distribution hole groups are alternately arranged. The diameter of the first air distribution hole is smaller than the diameter of the second air distribution hole. The horizontal distance between the first and second air distribution holes is equal to the vertical distance between them. Each combustion hole includes multiple main flame holes, flame stabilizing holes, and backfire prevention holes. The main flame holes are evenly arranged in multiple rows. The longitudinal main flame hole groups are arranged in multiple groups of four to form multiple transverse main flame groups; the flame stabilizing holes are evenly arranged to form multiple rows of transverse flame stabilizing hole groups, which are located between two groups of transverse main flame groups. Each flame stabilizing hole is combined in pairs to form multiple longitudinally evenly distributed longitudinal flame stabilizing hole groups; the backfire prevention hole is located between two groups of longitudinal flame stabilizing hole groups; the main flame hole is a round hole; both the flame stabilizing hole and the backfire prevention hole are elongated. The diameter of the hole is greater than the width of the flame stabilizer hole and less than the length of the flame stabilizer hole; the cross-sectional area of ​​a single flame stabilizer hole is greater than the cross-sectional area of ​​a single main flame hole; the width of the anti-backfire hole is equal to the width of the flame stabilizer hole, the diameter of the main flame hole is greater than the width of the anti-backfire hole and less than the length of the anti-backfire hole, and the length of the anti-backfire hole is 0.3-0.4 times the length of the flame stabilizer hole; the proportion of the main flame hole on the combustion chamber is greater than the total proportion of the flame stabilizer hole and the anti-backfire hole on the combustion chamber.

2. The fully premixed burner according to claim 1, characterized in that, Both the first and second air distribution holes are round holes formed by stamping.

3. The fully premixed burner according to claim 1, characterized in that, The diameter of the first air distribution hole is 1.2 mm - 2.8 mm, and the diameter of the second air distribution hole is 1.2 mm - 2.8 mm.

4. The fully premixed burner according to claim 3, characterized in that, The distance between the first air distribution hole and the second air distribution hole in the lateral direction is 3mm-8mm.

5. The fully premixed burner according to claim 1, characterized in that, The diameter of the main fire hole is 0.5mm-0.9mm.

6. The fully premixed burner according to claim 1, characterized in that, The width of the flame stabilizing hole is 0.35mm-0.6mm, and the length is 4mm-8mm.

7. The fully premixed burner according to claim 1, characterized in that, The backfire prevention holes are divided into a first backfire prevention hole and a second backfire prevention hole of the same size, and the first backfire prevention hole and the second backfire prevention hole are arranged side by side.

8. The fully premixed burner according to claim 1, characterized in that, The mounting base includes a base body, a first mounting portion and a second mounting portion extending from the base body. The outer diameter of the first mounting portion is larger than the outer diameter of the second mounting portion. The first mounting portion and the second mounting portion are bent sequentially on the base body to form a stepped structure.

9. The fully premixed burner according to claim 1, characterized in that, It also includes a sealing disc for sealing the top of the distribution cylinder and the combustion cylinder. The sealing disc includes a disc body, a first sealing flange and a second sealing flange extending from the disc body. The outer diameter of the first sealing flange is smaller than the outer diameter of the second sealing flange. The first sealing flange and the second sealing flange are bent sequentially on the disc body to form a stepped structure. The disc body is embedded in the distribution cylinder. The outer wall of the first sealing flange abuts against the inner wall of the distribution cylinder, and the outer wall of the second sealing flange abuts against the inner wall of the combustion cylinder.

10. A main heat exchanger, characterized in that, Including the fully premixed burner as described in any one of claims 1-9.

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