Convex porous medium evaporative burner and use method

Abstract

The present invention discloses a convex porous medium evaporative burner and a method for using the same. After the glow plug reaches a burning state, the fuel in the liquid fuel guide pipe is supplied to the fuel evaporation circuit, the fuel is absorbed by the oil-absorbing porous medium, and the fuel on the surface of the oil-absorbing porous medium evaporates; after passing through the air guide channel, the air passes through the air inlet holes on the wall of the inner cylinder of the combustion chamber to form a jet air, which is blown toward the oil-absorbing porous medium and fully mixed with the fuel; when the glow plug reaches the ignition point of the fuel, the mixed gas of the fuel and air is ignited, and the gas blown upward passes through the return air baffle, so that the wind in the flow dead zone flows back to the oil-absorbing porous medium, accelerates evaporation, and better mixes with the air, thereby overcoming the problems of insufficient combustion and reduced combustion efficiency in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel evaporative burners, and in particular relates to a convex porous medium evaporative burner and a use method thereof. Background Art

[0002] As the core component of the combustion heater, the burner has a significant impact on the fuel combustion efficiency. Therefore, improving the fuel combustion efficiency is an important method to improve the efficiency of the combustion heater. The evaporation and combustion conditions of the fuel have a significant impact on the thermal efficiency and pollution emissions of the heater. Traditional evaporative burners are mostly simple cylindrical burners. In practice, such burners often have excessively high pollution emissions. Porous media evaporative combustion can effectively improve combustion efficiency and reduce pollution to the environment. At the same time, its own design structure can reduce the flow dead zone, making it difficult to form carbon deposits on the inner avoidance surface, thereby improving exhaust gas emissions.

[0003] At present, fuel evaporation technology is used to improve combustion efficiency. After the fuel evaporates, the fuel vapor in the center area of ​​the combustion chamber is relatively far away from the air inlet hole on the combustion chamber wall. The fuel vapor in the center area of ​​the combustion chamber is not fully mixed with the air, so the fuel cannot be fully burned.

[0004] Patent 201510641333.7 proposes a "camping combustion heating stove". After the combustion of this device is stable, the liquid fuel absorbs heat and vaporizes. A flow stabilizer is provided to improve the mixing degree of fuel vapor and air. When the mixture lacks air during the combustion process, air cannot be provided, resulting in incomplete combustion and reduced combustion efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a convex porous medium evaporative burner and a method of using the same to improve combustion efficiency.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A convex porous medium evaporative burner comprises a combustion chamber cylinder; a combustion chamber inner cylinder is provided at the front end of the combustion chamber cylinder, a combustion chamber rear cover is provided at the front end of the combustion chamber cylinder, a liquid fuel guide pipeline is provided on the combustion chamber rear cover, an oil delivery hole and a plurality of fuel evaporation circuits are provided on the upper surface of the combustion chamber rear cover, the plurality of fuel evaporation circuits are connected with the oil delivery hole, and the liquid fuel guide pipeline passes through the combustion chamber rear cover and is connected with the oil delivery hole; an oil-absorbing porous medium is provided on the combustion chamber rear cover; a glow plug is provided above the oil-absorbing porous medium; a plurality of rows of air inlet holes are provided on the combustion chamber cylinder; an air guide channel is formed in the space between the combustion chamber cylinder and the combustion chamber outer cylinder, and a return air baffle with an opening is provided at the end of the air guide channel.

[0008] Furthermore, the longitudinal section of the combustion chamber rear cover is a parabola, the oil delivery hole is located at the center of the combustion chamber rear cover, and the fuel evaporation circuit is connected to the oil delivery hole.

[0009] Furthermore, the oil-absorbing porous medium material is a metal or non-metal in a porous foam or porous fiber felt shape. When the oil-absorbing porous medium is in a porous foam shape, the pore density is 3000PPI~8000PPI, and the porosity is 0.5~0.7; when the oil-absorbing porous medium is in a porous fiber felt shape, the average pore diameter is 0.18~0.42mm, and the average wire diameter is 1~10μm; the thickness of the oil-absorbing porous medium is 6~12mm.

[0010] Furthermore, the glow plug is arranged in parallel with the oil-absorbing porous medium, and the distance between the glow plug and the oil-absorbing porous medium is 2 to 6 mm.

[0011] Furthermore, the return air baffle includes two connected parts, one of which is a straight section and the other is a curved section. The angle between the straight section and the inner cylinder of the combustion chamber is 45° to 75°, and the curved section is fan-shaped. The ratio of the fan radius to the radius of the combustion chamber is 1:5, and the fan angle is 50° to 70°.

[0012] The return air baffle having a straight longitudinal section is provided with 5 to 8 bypass holes with a diameter of 1.5 to 3 mm.

[0013] Furthermore, the air intake holes are arranged in three rows. The first row of air intake holes is located near the rear cover of the combustion chamber. The distance between the first row of air intake holes and the rear cover of the combustion chamber is 16 to 21 mm. The interval between each row of air intake holes is 20 to 23 mm. The first row of air intake holes includes 2 to 4 groups of air intake ports, and each group includes three air intake holes with a hole diameter of 3 mm and two air intake holes with a hole diameter of 1.5 mm.

[0014] The second row of air intake holes includes 2 to 3 groups of air intake holes, each group of air intake holes includes three air intake holes with a hole diameter of 3mm and one air intake hole with a hole diameter of 1.5mm;

[0015] The third row of air intake holes includes 2 to 4 groups of air intake holes, each group includes three air intake holes with a hole diameter of 3 mm;

[0016] The ratio of the number of air inlet holes in two adjacent rows is 1:(0.7~0.8).

[0017] Furthermore, the central axis of the first row of air intake holes and the second row of air intake holes forms an angle of 15° to 45° with the tangent line of the combustion chamber inner cylinder at the opening.

[0018] Furthermore, an air intake diverter plate is provided at the front end of the air guide channel, and 15 to 25 air intake diverter holes with a diameter of 10 to 15 mm are evenly distributed on the air intake diverter plate. The angle between the longitudinal section of the air intake diverter hole and the longitudinal section of the outer cylinder of the combustion chamber corresponding to the air intake diverter hole is 20° to 40°, and the angle between the central axis of the air intake diverter hole and the surface of the air intake diverter plate is 60° to 80°.

[0019] Furthermore, the combustion chamber inner tube is made of stainless steel; the width of the fuel evaporation circuit gradually widens from close to the oil delivery hole to away from the oil delivery hole, close to the oil delivery hole is the proximal end, and away from the oil delivery hole is the distal end, the proximal end width is 2 to 4 mm, the distal end width is 4 to 6 mm, the depth of the fuel evaporation circuit is 1.5 to 3 mm, and there are 10 to 15 fuel evaporation circuits; the diameter of the oil delivery hole is 5 to 6 mm.

[0020] Furthermore, the oil-absorbing porous medium is closely attached to the inner surface of the combustion chamber rear cover, and the coordinates (x, y) of any point on the longitudinal section between the combustion chamber rear cover and the oil-absorbing porous medium satisfy the quadratic function equation:

[0021] y=ax 2 +b

[0022] Among them, the x0y coordinate system is centered on the burner center, the value range of a is -0.021 to -0.018, the value range of b is 29.493 to 32.967, the positive direction of the y-axis is away from the rear cover of the combustion chamber, the plane where the x-axis is located coincides with the upper surface of the air intake diverter plate, and the intersection of the x-axis and the curve represented by the equation is the endpoint of the rear cover of the combustion chamber.

[0023] In the method of using the convex porous medium evaporative burner as described above, after the glow plug reaches the burning state, the fuel in the liquid fuel guide pipe is supplied to the fuel evaporation circuit, the fuel is absorbed by the oil-absorbing porous medium, and the fuel evaporates on the surface of the oil-absorbing porous medium; after passing through the air guide channel, the air forms a jet air through the air inlet holes on the wall of the combustion chamber cylinder, and blows toward the oil-absorbing porous medium, and is fully mixed with the fuel in the combustion chamber; when the glow plug reaches the ignition point of the fuel, the mixed gas of fuel and air is ignited, and the upward blowing gas is blown toward the return air baffle, and the heated gas heats the oil-absorbing porous medium through the reflux effect, thereby accelerating the evaporation of the fuel.

[0024] Compared with the prior art, the present invention has the following beneficial effects: the present invention reduces the flow dead zone in the combustion chamber by setting a return air baffle, and at the same time, the gas reflux is blown toward the oil-absorbing porous medium, thereby accelerating the evaporation of fuel; the present invention sets a combustion chamber rear cover and an oil-absorbing porous medium to expand the surface of the oil-absorbing porous medium, thereby improving the evaporation efficiency of the fuel and obtaining sufficient mixing.

[0025] Furthermore, the present invention forms rotating gas by arranging an air intake diverter plate and opening an air intake diverter hole.

[0026] Furthermore, the present invention sets air inlet holes of different sizes in the inner cylinder of the combustion chamber so that the air flow entering the combustion chamber has a tangential velocity and blows toward the inner wall of the combustion chamber, reducing carbon deposition on the inner wall surface and fully mixing the vaporized fuel with the air.

[0027] Furthermore, the combustion chamber rear cover has a parabolic longitudinal cross-section, with 10 to 15 fuel evaporation circuits, ensuring that the fuel reaches the end of the oil-absorbing medium. Too many fuel evaporation circuits are necessary, as this can lead to fuel accumulation, preventing localized fuel from evaporating quickly and forming carbon deposits within or on the porous medium. Too few circuits, however, and the radiation from the high-temperature gas can carbonize the porous oil-absorbing medium, hindering fuel diffusion.

[0028] Furthermore, there are 15 to 25 air inlet diversion holes evenly distributed on the air inlet diversion plate, with a diameter of 10 to 15 mm. Too many holes or too large a diameter will affect the air speed, while too few holes or too small a diameter will affect the air swirl speed and fail to achieve the swirl effect.

[0029] Furthermore, the thickness of the oil-absorbing porous medium is 6 to 12 mm, in order to evenly spread the oil on the surface of the oil-absorbing porous medium and accelerate the evaporation of the fuel.

[0030] Furthermore, a number of air intake holes are set on the inner cylinder of the combustion chamber, and the number of air intake holes around the inner cylinder of the combustion chamber gradually decreases from the end to the tail of the inner cylinder of the combustion chamber. A large amount of air is provided to mix with the fuel vapor at the initial stage of mixing, so that there is sufficient air when the fuel vapor starts to burn, preventing incomplete combustion from producing carbon deposits. At the same time, the air with a jet effect will be blown toward the inner wall of the combustion chamber, reducing carbon deposits on the inner wall.

[0031] Furthermore, bypass holes are provided around the rear end of the air guide channel at the end of the return air baffle. These holes have a diameter of 1.5 to 3 mm and are numbered 5 to 8. These bypass holes blow into the dead zone of the combustion chamber. The return air baffle consists of two connected parts: one with a straight longitudinal section and the other with a curved section. The straight section forms an angle of 45° to 75° with the combustion chamber inner cylinder, while the curved section is fan-shaped. The ratio of the fan radius to the combustion chamber inner cylinder radius is 1:5, and the fan angle is 50° to 70°. This structure not only reduces the dead zone between the combustion chamber inner cylinder and the outer cylinder, but also blows the return gas toward the oil-absorbing porous medium, accelerating fuel evaporation and improving mixing with air.

[0032] After the glow plug reaches the burning state, the fuel in the liquid fuel guide pipe is supplied to the fuel evaporation circuit, absorbed by the oil-absorbing porous medium, and evaporated on the surface of the oil-absorbing porous medium; after passing through the air guide channel, the air passes through the air inlet holes on the wall of the inner cylinder of the combustion chamber to form a jet air, which is blown toward the oil-absorbing porous medium and fully mixed with the fuel; when the glow plug reaches the ignition point of the fuel, the mixed gas of fuel and air is ignited, and the upward-blowing gas passes through the return air baffle and is blown toward the oil-absorbing porous medium through reflux, accelerating evaporation, overcoming the incomplete combustion in the existing technology and solving the problem of combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the overall structure of a convex porous medium evaporative burner;

[0034] Figure 2 This is a schematic diagram of the combustion chamber inner cylinder structure;

[0035] Figure 3 Schematic diagram of the air intake manifold structure;

[0036] Figure 4 It is a schematic diagram of the combustion chamber rear cover structure;

[0037] Figure 5 It is a schematic diagram of the return air baffle structure.

[0038] Explanation of the accompanying symbols: 1. Combustion chamber; 2. Return air baffle; 3. Bypass hole; 4. Air inlet; 5. Glow plug; 6. Combustion chamber rear cover; 7. Air inlet diverter hole; 8. Liquid fuel guide pipe; 9. Fuel evaporation circuit; 10. Air inlet diverter plate; 11. Oil-absorbing porous medium; 12. Air guide channel; 13. Combustion chamber outer cylinder; 14. Flow dead zone; 15. Combustion chamber outer cylinder. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings.

[0040] See also Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 The convex porous medium evaporative burner of the present invention includes a combustion chamber 1, a return air baffle 2, an air inlet 4, a glow plug 5, a combustion chamber rear cover 6, an air inlet diversion hole 7, a liquid fuel guide pipe 8, a fuel evaporation circuit 9, an air inlet diversion plate 10, an oil-absorbing porous medium 11, an air guide channel 12, a combustion chamber inner cylinder 13 and a combustion chamber outer cylinder 15.

[0041] The front end of the combustion chamber outer cylinder 15 is provided with the combustion chamber inner cylinder 13, and the front end of the combustion chamber inner cylinder 13 is provided with the combustion chamber rear cover 6. The longitudinal section of the combustion chamber rear cover 6 is a parabola convex shape. Figure 4The combustion chamber rear cover 6 is provided with a liquid fuel guide pipe 8. An oil delivery hole and several fuel evaporation circuits 9 are formed on the upper surface of the combustion chamber rear cover 6. The oil delivery hole is located in the center of the combustion chamber rear cover 6, and the several fuel evaporation circuits 9 are all connected to the oil delivery hole. The liquid fuel guide pipe 8 passes through the combustion chamber rear cover 6 and is connected to the oil delivery hole. A porous oil-absorbing medium 11 is also provided on the combustion chamber rear cover 6.

[0042] The width of the fuel evaporation circuit 9 gradually widens from near the oil delivery hole to away from the oil delivery hole. The proximal end is 2-4 mm wide, while the distal end is 4-6 mm wide. The depth of the fuel evaporation circuit 9 is 1.5-3 mm, and the fuel evaporation circuit 9 has a certain oil storage function. 10-15 fuel evaporation circuits 9 are evenly distributed around the combustion chamber rear cover 6 to ensure more uniform oil diffusion. The diameter of the oil delivery hole is 5-6 mm to ensure better oil diffusion to the oil-absorbing porous medium at the end. The fuel evaporation circuit 9 is provided with an oil-absorbing porous medium 11, which is closely attached to the surface of the combustion chamber rear cover 6. The coordinates (x, y) of any point on the longitudinal section between the combustion chamber rear cover 6 and the oil-absorbing porous medium 11 satisfy the quadratic function equation:

[0043] y=ax 2 +b

[0044] The x0y coordinate system is centered on the burner, with a ranging from -0.021 to -0.018, and b ranging from 29.493 to 32.967. The positive y-axis points away from the combustion chamber rear cover 6, and the x-axis plane coincides with the upper surface of the intake manifold. The intersection of the x-axis and the curve represented by the equation represents the endpoint of the combustion chamber rear cover 6. Within this range, fuel evaporation is enhanced, and the jet of air is directed toward the porous medium. Outside this range, the oil-absorbing porous medium is too high, and the high-temperature gas will carbonize the fuel within the porous medium, affecting evaporation. If the oil-absorbing porous medium is too low, the air with tangential velocity will not reach the porous medium, reducing the evaporation rate.

[0045] The oil-absorbing porous medium 11 is made of a metal or non-metallic material in the form of porous foam or porous fiber felt. When the oil-absorbing porous medium 11 is in the form of porous foam, the pore density is 3000 PPI to 8000 PPI, and the porosity is 0.5 to 0.7. When the oil-absorbing porous medium 11 is in the form of porous fiber felt, the average pore size is 0.18 to 0.42 mm, and the average fiber diameter is 1 to 10 μm. The thickness of the oil-absorbing porous medium 11 is 6 to 12 mm. This ensures that the oil is evenly distributed across the surface of the oil-absorbing porous medium. If the oil-absorbing porous medium is too thick, the oil absorption resistance will increase, and the upper surface of the oil-absorbing felt will easily carbonize under high temperature conditions due to insufficient fuel. If the oil-absorbing felt is too thin, concentrated fuel supply combustion will occur, and the fuel will not be able to diffuse to the edges of the porous medium.

[0046] The glow plug 5 is arranged above the oil absorbing porous medium 11 , the direction of the glow plug 5 is parallel to the oil absorbing porous medium 11 , and the distance between the glow plug 5 and the oil absorbing porous medium 11 is 2 to 6 mm.

[0047] Several rows of air intake holes 4 are provided on the combustion chamber inner tube 13. The number of air intake holes 4 in each row gradually decreases from the end to the tail of the combustion chamber inner tube 13. The ratio of the number of air intake holes in two adjacent rows is 1:(0.7-0.8). Preferably, there are 3 rows of exhaust holes, and the central axis of the air intake holes 4 in the first 1 to 2 rows (the first row and the second row) forms an angle of 15° to 45° with the tangent of the combustion chamber inner cylinder 13 at the opening. The first row of air intake holes is close to the combustion chamber rear cover 6, and the distance between the first row of air intake holes and the combustion chamber rear cover 6 is 16 to 21 mm. After that, each row of air intake holes is spaced 20 to 23 mm apart. The first row of air intake holes consists of 3mm and 1.5mm air intake holes, and the arrangement is three 3mm and two 1.5mm to form a group, which are evenly distributed into 2 to 4 groups according to the diameter of the combustion chamber cylinder 13; the second row of air intake holes consists of 3mm and 1.5mm air intake holes, and the arrangement is three 3mm and one 1.5mm to form a group, which are evenly distributed into 2 to 3 groups according to the diameter of the combustion chamber cylinder 13; the aperture size of the third row of air intake holes is 3mm, and the arrangement is three 3mm to form a group, which are evenly distributed into 2 to 4 groups according to the diameter of the combustion chamber cylinder 13. This arrangement of exhaust holes provides a large amount of air to mix with the fuel vapor at the initial mixing stage, so that there is sufficient air when the fuel vapor begins to burn, preventing incomplete combustion and carbon deposits.

[0048] The space between the combustion chamber inner tube 13 and the combustion chamber outer tube 15 forms an air guide channel 12. An air intake manifold plate 10 is provided at the front end of the air guide channel 12. The combustion chamber inner tube 13 and the air intake manifold plate 10 are connected together. The air intake manifold plate 10 is also provided at the front end of the combustion chamber outer tube 15. The air intake manifold plate 10 is evenly distributed with 15 to 25 air intake manifold holes 7 with a diameter of 10 to 15 mm. The longitudinal cross-section of the air intake manifold hole 7 and the longitudinal cross-section of the combustion chamber outer tube 15 corresponding to the corresponding air intake manifold hole are at an angle of 20 to 40 degrees. The central axis of the air intake manifold hole 7 and the surface of the air intake manifold plate 10 are at an angle of 60 to 80 degrees. The air intake manifold plate 10 and the combustion chamber inner tube 13 are connected by welding.

[0049] The combustion chamber inner tube 13 is made of stainless steel with high thermal conductivity and high temperature resistance.

[0050] See also Figure 5The rear end of the combustion chamber cylinder 13 is connected to the combustion chamber cylinder 15 via a return air baffle 2. The return air baffle 2 consists of two connected parts: one with a straight longitudinal section and the other with a curved section. The straight section forms an angle of 45° to 75° with the combustion chamber cylinder. The curved section is fan-shaped, with a radius of the fan and a radius of the combustion chamber cylinder of 1:5. The fan-shaped curve in the longitudinal section is 0° toward the rear end of the combustion chamber cylinder, and the fan angle is 50° to 70°. Bypass holes 3 with a diameter of 1.5 to 3 mm are evenly distributed around the straight longitudinal section of the return air baffle 2. The number of bypass holes 3 is 5 to 8, and the bypass holes 3 blow into the combustion chamber flow dead zone 14.

[0051] The convex porous medium evaporative burner of the present invention is used as follows: First, the glow plug 5 is energized to achieve a burning state. An oil pump supplies oil to the liquid fuel conduit 8. The fuel in the liquid fuel conduit 8 enters the fuel evaporation circuit 9, where it is absorbed by the oil-absorbing porous medium 11 and diffuses to the end. The surface of the oil-absorbing porous medium 11, due to its proximity to the hot glow plug 5, is heated and evaporated. At this point, air from the combustion-supporting blower first passes through the air inlet manifold holes 7 in the air inlet manifold plate 10, initially forming a swirling air flow. Then, through the air inlet holes 4 in the wall of the combustion chamber inner tube 13, it forms a jet of air that blows toward the oil-absorbing porous medium 11, accelerating fuel evaporation and thoroughly mixing with the fuel. When the glow plug 5 reaches the ignition point of the fuel, the fuel-air mixture ignites. Initially, the flame is relatively small. The upwardly blowing air passes through the return air baffle 2 and flows back toward the oil-absorbing porous medium 11. The high-temperature air is then applied to the oil-absorbing porous medium 11, accelerating fuel evaporation and mixing. When there is a sufficient combustion temperature, the wind force of the combustion-supporting fan is increased, and the inlet velocity of the air guide channel 12 and the intake velocity of the air intake diversion hole 7 are significantly increased. The wind speed flowing through the air intake hole 4 is also significantly increased, more fuel is evaporated, the concentration of the mixed gas becomes larger and larger, and the flame becomes stronger. Due to the action of the return air baffle 2, the high-temperature and high-speed gas is blown onto the oil-absorbing porous medium 11, accelerating the evaporation of the fuel, increasing the concentration of the mixture, and maintaining the evaporation of the fuel. A small amount of air flows through the bypass hole 3 at the end of the air guide channel 12, and most of the air is blown toward the inner wall of the combustion chamber and the oil-absorbing porous medium 11 through the air intake hole 4. On the one hand, the return air baffle 2 has a larger speed and shape of the flame in the late stage of combustion, which plays a role in preventing backfire and flameout in the late stage of combustion and the stage of stopping combustion. On the other hand, part of the high-temperature flue gas refluxes, increasing the temperature in the combustion chamber and promoting the evaporation of the fuel.

Claims

1. A convex porous medium evaporative burner, characterized in that: The invention comprises a combustion chamber outer cylinder (15); a combustion chamber inner cylinder (13) is provided at the front end of the combustion chamber outer cylinder (15); a combustion chamber rear cover (6) is provided at the front end of the combustion chamber inner cylinder (13); a liquid fuel guide pipe (8) is provided on the combustion chamber rear cover (6); an oil delivery hole and a plurality of fuel evaporation circuits (9) are opened on the upper surface of the combustion chamber rear cover (6); the plurality of fuel evaporation circuits (9) are connected to the oil delivery hole; and the liquid fuel guide pipe (8) passes through the combustion chamber rear cover (6) and is connected to the oil delivery hole. An oil-absorbing porous medium (11) is provided on the combustion chamber rear cover (6); a glow plug (5) is provided above the oil-absorbing porous medium (11); a plurality of rows of air inlet holes (4) are provided on the combustion chamber inner cylinder (13); an air guide channel (12) is formed in the space between the combustion chamber inner cylinder (13) and the combustion chamber outer cylinder (15); a return air baffle (2) with an opening is provided at the end of the air guide channel (12); The longitudinal section of the combustion chamber rear cover (6) is a parabola, the oil delivery hole is located at the center of the combustion chamber rear cover (6), and the fuel evaporation circuit (9) is connected to the oil delivery hole; The glow plug (5) is arranged in parallel with the oil-absorbing porous medium (11), and the distance between the glow plug (5) and the oil-absorbing porous medium (11) is 2 to 6 mm; The return air damper (2) comprises two connected parts, one of which is a straight part in longitudinal section and the other is a curved part, the angle between the straight part in longitudinal section and the inner cylinder of the combustion chamber is 45° to 75°, the curved part in longitudinal section is fan-shaped, the ratio of the fan-shaped radius to the radius of the combustion chamber cylinder is 1:5, and the fan-shaped angle is 50° to 70°; The return air baffle (2) having a straight section is provided with 5 to 8 bypass holes (3) each having a diameter of 1.5 to 3 mm; The air intake holes are arranged in three rows. The first row of air intake holes is located near the combustion chamber rear cover (6). The distance between the first row of air intake holes and the combustion chamber rear cover is 16 to 21 mm. The interval between each row of air intake holes is 20 to 23 mm. The first row of air intake holes includes 2 to 4 groups of air intake ports, and each group includes three air intake holes with a hole diameter of 3 mm and two air intake holes with a hole diameter of 1.5 mm. The second row of air intake holes includes 2 to 3 groups of air intake holes, each group of air intake holes includes three air intake holes with a hole diameter of 3mm and one air intake hole with a hole diameter of 1.5mm; The third row of air intake holes includes 2 to 4 groups of air intake holes, each group includes three air intake holes with a hole diameter of 3 mm; The ratio of the number of air inlet holes in two adjacent rows is 1:(0.7-0.8); The combustion chamber inner cylinder (13) is made of stainless steel; the width of the fuel evaporation circuit (9) gradually widens from the direction close to the oil delivery hole to the direction away from the oil delivery hole, the part close to the oil delivery hole is the proximal end, and the part away from the oil delivery hole is the distal end, the proximal end width is 2 to 4 mm, and the distal end width is 4 to 6 mm, the depth of the fuel evaporation circuit (9) is 1.5 to 3 mm, and there are 10 to 15 fuel evaporation circuits (9); the diameter of the oil delivery hole is 5 to 6 mm; The oil-absorbing porous medium (11) is closely attached to the inner surface of the combustion chamber rear cover (6), and the coordinates (x, y) of any point on the longitudinal section between the combustion chamber rear cover (6) and the oil-absorbing porous medium (11) satisfy the following formula: y=ax 2 +b The x0y coordinate system is centered on the burner center, the value range of a is -0.021 to -0.018, the value range of b is 29.493 to 32.967, the positive direction of the y-axis is away from the combustion chamber rear cover (6), and the plane where the x-axis is located coincides with the upper surface of the air inlet diverter plate.

2. The convex porous medium evaporative burner according to claim 1, characterized in that: The oil-absorbing porous medium (11) is made of a metal or non-metal in a porous foam or porous fiber felt shape. When the oil-absorbing porous medium (11) is in a porous foam shape, the pore density is 3000PPI to 8000PPI, and the porosity is 0.5 to 0.

7. When the oil-absorbing porous medium (11) is in a porous fiber felt shape, the average pore diameter is 0.18 to 0.42mm, and the average wire diameter is 1 to 10μm. The thickness of the oil-absorbing porous medium (11) is 6 to 12mm.

3. The convex porous medium evaporative burner according to claim 1, characterized in that: An air intake diverter plate (10) is provided at the front end of the air guide channel (12). 15 to 25 air intake diverter holes (7) with a diameter of 10 to 15 mm are evenly distributed on the air intake diverter plate (10). The angle between the longitudinal section of the air intake diverter hole (7) and the longitudinal section of the combustion chamber outer cylinder (15) corresponding to the air intake diverter hole is 20° to 40°, and the angle between the central axis of the air intake diverter hole (7) and the surface of the air intake diverter plate (10) is 60° to 80°.

4. The method for using the convex porous medium evaporative burner according to claim 1, wherein: After the glow plug (5) reaches the burning state, the fuel in the liquid fuel guide pipe (8) is supplied to the fuel evaporation circuit (9), the fuel is absorbed by the oil-absorbing porous medium (11), and the fuel on the surface of the oil-absorbing porous medium (11) evaporates; the air passes through the air guide channel (12) and the air inlet hole (4) on the wall of the combustion chamber inner cylinder (13) to form a jet air, which is blown toward the oil-absorbing porous medium (11) and fully mixed with the fuel in the combustion chamber (1); when the glow plug (5) reaches the ignition point of the fuel, the mixed gas of the fuel and air is ignited, and the gas blowing upward is blown toward the return air baffle (2), and the heated gas is heated by the reflux effect of the oil-absorbing porous medium, thereby accelerating the evaporation of the fuel.

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