Cooker burner and cooker

Abstract

The present invention relates to a stove burner and a stove, wherein the stove burner comprises a base, having an inner ring wall in an annular shape and an outer ring cavity located outside the inner ring wall and open at the top; an inner ring fire cover, covering the inner ring wall of the base, and enclosing an inner ring gas mixing chamber with the inner ring wall, on which a fire outlet hole connected to the inner ring gas mixing chamber is provided; an infrared combustion plate, in an annular shape, with fire holes distributed thereon, arranged at a position adjacent to the top of the outer ring cavity and covering the top opening of the outer ring cavity; characterized in that: a guide hole is provided on the inner ring fire cover, and a gap is left between the inner ring wall at least at a local position adjacent to its top edge and the bottom surface of the inner ring fire cover, and the gap is fluidly connected to the fire outlet hole through the guide hole. Compared with the prior art, the advantage of the present invention is that when overflow flows into the fire outlet hole, it will flow into the gap through the guide hole, preventing the overflow from accumulating in the fire outlet hole and blocking the fire outlet hole.

Description

Technical Field

[0001] The invention belongs to the technical field of stoves, and in particular relates to a stove burner and a stove. Background Art

[0002] The burner is one of the important components of a gas stove, which directly affects the stove's flue gas, thermal efficiency and other performance.

[0003] Existing burner structures, such as the Chinese utility model "A Burner for Cookers" previously applied for by the applicant, whose patent number is ZL201821028377.8 (authorization announcement number is CN208886771U), discloses a burner for cookers, including an outer ring cavity, the outer ring cavity including an inner ring wall and an outer ring wall that are annular and concentrically spaced, and a bottom wall connecting the inner ring wall and the outer ring wall, the inner ring wall and the outer ring wall are covered with an outer ring fire cover, characterized in that: the outer ring cavity has a relatively isolated secondary air replenishment chamber, the top wall of the outer ring fire cover has main fire holes and an air outlet of the secondary air replenishment chamber distributed radially and at intervals, and the inner ring wall and / or outer ring wall and / or bottom wall of the outer ring cavity are provided with an air inlet connected to the outside air and the air outlet at a position corresponding to the secondary air replenishment chamber.

[0004] The maximum flame temperature of the above-mentioned atmospheric stove is generally around 850°C. The pot body is heated by convection and heat radiation of high-temperature flue gas, of which convection heating accounts for about 80% and radiation heating accounts for 20%. The heat load is large. Convection heating of the pot body is limited by the heat absorption capacity of the pot body. The temperature of the flue gas exhausted from the bottom of the pot is relatively high. Nearly a quarter of the heat is carried away by the exhausted flue gas and dissipated into the surrounding environment. The maximum thermal efficiency can only reach about 78%.

[0005] In order to solve the above technical problems, the Chinese utility model "A New High-efficiency Energy-saving and Environmentally Friendly Burner" previously applied by the applicant, whose patent number is ZL201320429097.9 (authorization announcement number is CN 203404810 U), discloses a new high-efficiency energy-saving and environmentally friendly burner, including a body, the body includes an outer ring flame generator formed with an outer ring mixing chamber, an infrared burner is arranged inside the body, the infrared burner includes an inner mixing chamber connected to an inner ejector tube and a combustion plate arranged above the inner mixing chamber, the combustion plate is located on the body space surrounded by the outer ring fire cover, and a fire outlet is arranged on the combustion plate. The patent adopts a combination of infrared and atmospheric combustion, and the combustion efficiency and exchange efficiency are higher, so that the flame wavelength of the outer ring flame generator is less than 0.76μm, the flame wavelength of the middle ring flame generator is between 0.75 and 40μm, and the flame wavelength of the inner ring flame generator is between 25 and 1000μm, so that the burner adopts "full-band" technology. However, flames are prone to escape from the outer ring fire cover, and if the combustion plate area is the same, the diameter will be too large if it is arranged in the inner ring, and the small firepower of the inner ring cannot be achieved.

[0006] Another example is the Chinese utility model patent "An infrared burner with atmospheric combustion", whose patent number is ZL201821677211.9 (authorization announcement number is CN209180935U), which discloses an infrared burner including an inner ring air mixing chamber, an outer ring air mixing chamber and a middle ring air mixing chamber located between the outer ring air mixing chamber and the inner ring air mixing chamber. A circular infrared combustion plate is provided on the outer ring air mixing chamber. There is no secondary air supplement in the middle cavity, and the combustion is incomplete. In addition, overflow is easily accumulated in the fire outlet and blocks the fire outlet. Summary of the invention

[0007] The first technical problem to be solved by the present invention is to provide a stove burner which can achieve sufficient combustion while avoiding the blockage of the fire outlet in view of the current status of the above-mentioned prior art.

[0008] The second technical problem to be solved by the present invention is to provide a stove having the above stove burner which can achieve sufficient combustion while reducing heat loss to improve thermal efficiency.

[0009] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a stove burner, comprising

[0010] The base has an inner ring wall in an annular shape and an outer ring cavity located outside the inner ring wall and open at the top;

[0011] An inner ring fire cover, covering the inner ring wall of the base, and enclosing an inner ring gas mixing chamber with the inner ring wall, and having a fire outlet hole connected to the inner ring gas mixing chamber;

[0012] The infrared combustion plate is annular and has fire holes distributed thereon, and is disposed adjacent to the top of the outer ring cavity to cover the top opening of the outer ring cavity;

[0013] The feature is that a guide hole is provided on the inner ring fire cover, a gap is left between the inner ring wall at least in a local position adjacent to its top edge and the bottom surface of the inner ring fire cover, and the gap is fluidically connected with the fire outlet hole through the guide hole.

[0014] There are many ways to form the gap. The top edge of the inner ring wall can be gradually tilted downward from the outside to the inside to form a gap between the inner ring fire cover, or a step can be formed at the inner edge of the top edge of the inner ring wall to form a gap between the inner ring fire cover. However, preferably, the inner edge of the top edge of the inner ring wall is concave to form a step portion, and the gap is formed between the step portion and the bottom surface of the inner ring fire cover.

[0015] In order to prevent the overflow from entering the gas mixing chamber, the inner periphery of the inner ring fire cover extends downward to form ribs, which are in contact with the inner side wall of the inner ring wall. In this way, the ribs, the gap, the inner ring fire cover and the inner ring wall enclose a receiving cavity for receiving the overflow.

[0016] There are many forms of forming the fire hole. It can be directly opened on the inner ring fire cover, or it can adopt other forms. However, preferably, the inner ring fire cover includes a lower cover and an upper cover placed on the lower cover, and the fire hole is the fire gap formed at the outer periphery between the upper cover and the lower cover.

[0017] Specifically, convex ribs are arranged between the lower cover and the upper cover, there are at least two convex ribs, and they are arranged radially from the center of the inner ring fire cover, and relatively independent gas channels are formed between two adjacent convex ribs, and the guide holes are opened at the position of the lower cover corresponding to the gas channel and are located above the gap.

[0018] In order to guide the overflow into the gap and prevent the gas channel and the ignition gap from being blocked, each gas channel corresponds to a guide hole, and the step portion extends circumferentially. In this way, the step portion extends circumferentially, and the gap formed by the enclosed portion extends circumferentially. When overflow enters the gas channel, it will flow into the gap through the guide hole, thereby preventing the gas channel from being blocked.

[0019] In order to achieve the purpose of flame stabilization, the lower cover is cone-shaped, and the convex ribs are arranged on the upper surface of the lower cover, and each convex rib extends along a direction having an acute angle with the radial direction, so that the whole presents a clockwise or counterclockwise rotation direction in the circumferential direction. In this way, the gas flows out through the gas channel in a rotating manner to form a rotating fire, thus achieving the purpose of flame stabilization.

[0020] Preferably, a central hole is provided at the central position of the upper cover, which passes through from top to bottom and is connected to the inner ring air mixing chamber. The upper cover is covered with a cover plate at a position corresponding to the central hole, and a fire outlet hole is provided on the cover plate.

[0021] In order to reduce radiation loss, the inner peripheral edge of the infrared combustion plate is lower than the outer peripheral edge thereof, so as to reduce the escape of infrared rays and reduce heat energy loss.

[0022] In order to provide the secondary air required for inner ring combustion, an air supply cavity is formed between the inner ring air mixing chamber and the outer ring cavity. The air supply cavity is fluidly connected to the inner ring air mixing chamber through a fire outlet hole. At least one air supply channel for connecting the air supply cavity with the outside is provided on the base.

[0023] In order to achieve the purpose of ignition, the air replenishing cavity has a vertically penetrating channel, and an ignition needle is arranged in the channel.

[0024] In order to facilitate the entry of external air into the air replenishment cavity, there are at least two air replenishment channels, which are radially arranged in the outer ring cavity with the center of the air replenishment cavity, and the air inlet of the air replenishment channel is formed on the outer peripheral wall of the base.

[0025] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a stove with the above-mentioned stove burner, characterized in that it includes an annular energy focusing cover, the energy focusing cover is located at the periphery of the burner, and the outer peripheral wall of the energy focusing cover is provided with a secondary air inlet fluidly connected to the air supply channel.

[0026] In order to improve the replenishment efficiency, the secondary air inlet is staggered with the air inlet of the air replenishment channel, the air replenishment channel corresponds to two secondary air inlets, and the projection of the air inlet on the energy gathering cover along the centerline direction of the energy gathering cover is located between the two secondary air inlets. After the secondary air flows in through the secondary air inlets on both sides of the air replenishment channel, it flows toward the air inlet. In this way, the air is replenished through the secondary air inlets on both sides, which improves the replenishment efficiency, and can preheat the air and effectively recover energy losses.

[0027] There are many ways to set up the secondary air inlet. It can be opened at the bottom of the cavity or at other locations. However, from the perspective of convenient air intake, preferably, the interior of the energy concentrating hood is hollow to form a cavity, and the outer periphery of the energy concentrating hood extends downward to form an annular convex wall located below the cavity, and the secondary air inlet is opened on the annular convex wall.

[0028] In order to facilitate the diversion of the airflow flowing in through the secondary air inlet to the air inlet, a guide group is arranged between the secondary air inlet and the air inlet along the airflow path. The guide group is arranged on the outer side of the bottom wall of the cavity and includes at least one guide plate extending in the circumferential direction.

[0029] Preferably, the guide group includes at least two guide vanes spaced apart in the radial direction, a guide channel is formed between two adjacent guide vanes, and the guide channel is in the shape of an arc curved radially outward, so that the secondary air can be introduced into the air inlet, reducing the escape of the secondary air.

[0030] Compared with the prior art, a gap is left between the inner ring fire cover and the inner ring wall of the present invention, and a guide hole is opened on the inner ring fire cover which is fluidically connected with the gap and the fire outlet hole. When overflow flows into the fire outlet hole, it will flow into the gap through the guide hole to prevent the overflow from accumulating in the fire outlet hole and blocking the fire outlet hole; and a semi-atmospheric and semi-infrared burner combining atmospheric combustion and infrared combustion is adopted to prevent the outer ring fire from escaping and burning the energy gathering ring. In this way, the temperature of the energy gathering ring is prevented from being too high and transferring heat to the stove panel, thereby reducing the probability of thermal explosion of the stove panel and improving combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0032] Figure 2 for Figure 1 A cross-sectional view of

[0033] Figure 3 for Figure 2 The enlarged structural diagram of the middle A part;

[0034] Figure 4 It is a schematic diagram of the assembly structure of the base and the energy-gathering cover;

[0035] Figure 5 It is a cross-sectional view of the assembly structure of the base, the energy-gathering cover and the pot support;

[0036] Figure 6 for Figure 4 Schematic diagram of the structure of the middle energy-gathering hood;

[0037] Figure 7 for Figure 6 A schematic diagram of the structure from another angle;

[0038] Figure 8 for Figure 6 A cross-sectional view of

[0039] Fig. 9 for Figure 1 A schematic diagram of the structure of the base;

[0040] Fig.10 It is a schematic diagram of the structure of the inner ring fire cover;

[0041] Fig.11 for Fig.10Schematic diagram of the three-dimensional decomposition structure;

[0042] Fig.12 is a schematic structural diagram of a cooker of the present invention;

[0043] Fig.13 for Fig.12 A cross-sectional view of a portion of the structure. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below with reference to the accompanying drawings.

[0045] like Figures 1 to 13 As shown, the stove in the embodiment of the present invention includes a stove panel 10 , a burner, an energy collecting cover 6 , a liquid receiving tray B and a pot support 9 .

[0046] like Fig.10 As shown, a mounting hole is provided on the cooker panel 10, the burner is embedded in the mounting hole 101, the energy collecting cover 6 is placed on the cooker panel 10 through the liquid receiving pan B, and the energy collecting cover 6 surrounds the burner, see Fig.13 as shown; Figure 7 As shown, the energy collecting cover 6 is hollow inside to form a cavity 61, and a partition plate 62 is arranged in the cavity 61. The partition plate 62 extends along the circumferential direction and is arranged transversely. The cavity 61 is divided into at least two independent sub-chambers 611 arranged up and down by the partition plate 62. For details, see Figure 5 , Figure 8 and Fig.13 In addition, the upper surface of the partition plate 62 is a reflective surface 621 that reflects infrared rays. Figure 5 and Fig.12 As shown, the pot support 9 is arranged on the energy focusing cover 6, and the pot support 9 is an annular support ring. The pot support 9 has at least two supporting feet 91 for supporting the pot arranged at intervals along the circumference. In this embodiment, there are four supporting feet 91.

[0047] like Figure 1 and Figure 2 As shown, the burner includes a base 1, an inner ring fire cover 2, an infrared combustion plate 3 and an ignition needle 8. Figures 2 to 5 As shown, the base 1 has an inner ring wall 11 that is annular and extends upward, an outer ring cavity 12 located outside the inner ring wall 11, and an air supplement cavity 13 located between the inner ring wall 11 and the outer ring cavity 12. The air supplement cavity 13 is used to supplement secondary air to the flame of the inner ring fire cover 2; Fig. 9 As shown, the tops of the inner ring wall 11, the outer ring cavity 12 and the air supplement cavity 13 are all open.

[0048] like Figure 1 and Fig. 9As shown, the base 1 is provided with two mixed gas channels, namely, an inner ring channel 15 and an outer ring channel 16 provided on the bottom of the base 1. The inner ring channel 15 is used to connect with the inner ring ejector tube 171, and the inner ring channel 15 is connected with the inner cavity of the inner ring wall 11; the outer ring channel 16 is used to connect with the outer ring ejector tube 172, and the outer ring channel 16 is connected with the outer ring cavity 12, so that the base 1 can receive the mixed gas from the ejector tube. Figures 1 to 3 As shown, the inner ring fire cover 2 covers the inner ring wall 11 of the base 1, and an inner ring gas mixing chamber 110 is formed between the inner ring fire cover 2 and the inner ring wall 11; the inner ring fire cover 2 has a fire outlet hole in fluid communication with the inner ring gas mixing chamber 110, specifically, the inner ring fire cover 2 includes a lower cover 21 and an upper cover 22 placed on the lower cover 21, and the fire outlet hole is a fire outlet gap d formed at the outer periphery between the upper cover 22 and the lower cover 21. A central hole 220 is provided in the center of the upper cover 22, which passes through from top to bottom and is connected to the inner ring gas mixing chamber 110. The upper cover 22 is covered with a cover plate 23 at a position corresponding to the central hole 220, and a fire outlet through hole 231 is provided on the cover plate 23, see for details. Figure 3 shown.

[0049] In addition, in order to prevent liquid overflow, the upper cover 22 includes a top plate 22a, on which a central hole 220 is opened, and an extension tube 22b is extended downward around the central hole 220. The bottom surface of the top plate 22a has a concave and annular groove 223. The presence of the groove 223 reduces the risk of liquid overflowing from entering the fire outlet hole and clogging the fire outlet hole.

[0050] like Figure 3 As shown, a guide hole 210 is provided on the inner ring fire cover 2, and a gap 111 is left between the inner ring wall 11 and the bottom surface of the inner ring fire cover 2 at least at a local position adjacent to the top edge thereof, and the gap 111 is fluidically connected with the fire outlet through the guide hole 210. Specifically, the inner edge of the top edge of the inner ring wall 11 is concave to form a step portion 11a extending in the circumferential direction, and a gap 111 is formed between the step portion 11a and the bottom surface of the inner ring fire cover 2. The gap 111 extends in the circumferential direction, and the gap 111 is independent of the inner ring gas mixing chamber 110. Specifically, the inner circumference of the inner ring fire cover 2 extends downward to form a rib 213, and the rib 213 contacts the inner side wall of the inner ring wall 11. The lower cover 21 is provided with a guide hole 210, which is in fluid communication with the gap 111 and the fire outlet hole, and the guide hole 210 is located above the gap 111. Specifically, Fig.10 and Fig.11As shown, the lower cover 21 is cone-shaped, and a rib 211 is provided between the lower cover 21 and the upper cover 22. There are at least two ribs 211, which are radially arranged on the upper surface of the lower cover 21 with the center of the inner ring fire cover 2, and the ribs 211 gradually tilt upward along the circumferential direction from the inside to the outside, so that the ribs 211 are arranged in a circumferential rotation direction as a whole. Specifically, each rib 211 extends along a direction that has an acute angle with the radial direction, so that the whole presents a clockwise or counterclockwise rotation direction in the circumferential direction. A relatively independent gas channel 212 is formed between two adjacent ribs 211, and each gas channel 212 is arranged in a rotation direction with the center of the inner ring fire cover 2. As shown Fig.11 As shown, the above-mentioned guide holes 210 are opened at positions corresponding to the gas channels 212, and each gas channel 212 corresponds to a guide hole 210, so that the overflow flows into the gap 111 through the guide holes 210 to prevent the overflow from blocking the gas channels 212.

[0051] like Figure 1 and Figure 2 As shown, the above-mentioned infrared combustion plate 3 is annular and is arranged in a position near the top of the outer ring cavity 12. The infrared combustion plate 3 is used to cover the top opening of the outer ring cavity 12. The infrared combustion plate 3 has a fire hole 31, and the infrared combustion plate 3 gradually tilts downward from the outside to the inside, so that the inner peripheral edge of the infrared combustion plate 2 is lower than its outer peripheral edge.

[0052] like Figure 2 and Figure 4 As shown, the air supplement chamber 13 is relatively independent from the inner ring air mixing chamber 110, and the air supplement chamber 13 is fluidically connected to the inner ring air mixing chamber 110 through the fire outlet; and the above-mentioned air supplement chamber 13 is connected to the outside through at least one air supplement channel 14. In this embodiment, there are four air supplement channels 14, which are arranged at intervals along the circumferential direction, and the four air supplement channels 14 are radially arranged in the outer ring cavity 12 with the center of the air supplement chamber 13, and the air inlet 142 of the air supplement channel 14 is opened on the outer peripheral wall of the base 1, and the air supplement channel 14 is not connected to the outer ring cavity 12. In order to facilitate ignition, as shown in FIG. Figure 2 As shown, the air supply cavity 13 has a vertically penetrating channel 131 , and an ignition needle 8 is arranged in the channel 131 , and the upper end of the ignition needle 8 faces the ignition hole of the inner ring fire cover 2 .

[0053] like Figures 4 to 7As shown, the peripheral wall of the energy-gathering hood 6 is provided with a secondary air inlet 6a in fluid communication with the air supply channel 14. Specifically, the peripheral edge of the energy-gathering hood 6 is extended downward to form an annular convex wall 64 in the shape of an annular ring. The annular convex wall 64 is located below the cavity 61. The secondary air inlet 6a is provided on the annular convex wall 64. The secondary air inlet 6a and the cavity 61 are not connected to each other and are located above the liquid receiving pan B. Along the air flow path, the secondary air inlet 6a is located upstream of the air supply channel 14, and there are four secondary air inlets 6a in this embodiment, and the four secondary air inlets 6a are staggered with the air inlet 142 of each air supply channel 14, that is, the projection of the air inlet 142 on the energy-gathering hood 6 along the center line of the inner ring fire cover falls between the two secondary air inlets 6a. For details, see Figure 5 shown.

[0054] In order to facilitate the flow of air flowing in through the secondary air inlet 6a to the air inlet 142, as shown in FIG. Figures 5 to 8 As shown, a guide group 63 is arranged on the airflow path between the secondary air inlet 6a and the air inlet 142. The guide group 63 is arranged on the bottom wall of the cavity 61 and is located on the outside of the cavity 61, and the guide group 63 includes at least one guide plate 631 extending in the circumferential direction. Specifically, the guide group 63 includes at least two guide plates 631 arranged at intervals in the radial direction. In the present embodiment, each guide group 63 has three guide plates 631, and a guide channel 632 is formed between two adjacent guide plates 631. The guide channel 632 is in the shape of an arc that bends radially outward.

[0055] The guide plate 631 in this embodiment is a heat exchange plate. The liquid pan B is arranged at the bottom of the energy collecting cover and above the stove panel 10 to contain overflow and oil. In this way, the air flowing under the action of the guide plate 631 can cool the bottom liquid pan B, reduce the temperature of the liquid pan B and the temperature of the stove panel 10, and reduce the probability of the stove panel exploding due to heat.

[0056] The infrared combustion plate in the above embodiment is formed by a plurality of annular porous ceramic plates, and other structures in the prior art may also be adopted.

[0057] The "fluid connection" referred to in the present invention refers to the spatial position relationship between two parts or parts (hereinafter collectively referred to as the first part and the second part respectively), that is, the fluid (gas, liquid or a mixture of the two) can flow from the first part along the flow path or / and be transported to the second part. The first part and the second part can be directly connected, or the first part and the second part can be indirectly connected through at least one third party. The third party can be a fluid channel such as a pipe, channel, duct, guide member, hole, groove, etc., or it can be a chamber allowing fluid to flow through, or a combination of the above.

Claims

1. A stove having a stove burner, the burner comprising The base (1) has an annular inner ring wall (11) and an outer ring cavity (12) located outside the inner ring wall (11) and open at the top; An inner ring fire cover (2) covers the inner ring wall (11) of the base (1) and forms an inner ring gas mixing chamber (110) with the inner ring wall (11), and is provided with a fire outlet hole connected to the inner ring gas mixing chamber (110); The infrared combustion plate (3) is annular and has fire holes (31) distributed thereon, and is arranged adjacent to the top of the outer ring cavity (12) to cover the top opening of the outer ring cavity (12); Features: The inner ring fire cover (2) is provided with a guide hole (210), and a gap (111) is left between the inner ring wall (11) and the bottom surface of the inner ring fire cover (2) at least at a local position adjacent to the top edge thereof, and the gap (111) is fluidically connected to the fire outlet hole through the guide hole (210); The inner edge of the top edge of the inner ring wall (11) is concave to form a step portion (11a), and the gap (111) is formed between the step portion (11a) and the bottom surface of the inner ring fire cover (2); The inner peripheral edge of the inner ring fire cover (2) extends downward to form ribs (213), and the ribs (213) are in contact with the inner side wall of the inner ring wall (11); The inner ring fire cover (2) comprises a lower cover (21) and an upper cover (22) placed on the lower cover (21), and the fire outlet hole is a fire outlet gap (d) formed at the outer periphery between the upper cover (22) and the lower cover (21); A convex rib (211) is provided between the lower cover (21) and the upper cover (22); there are at least two convex ribs (211) which are radially arranged at the center of the inner ring fire cover (2); a relatively independent gas channel (212) is formed between two adjacent convex ribs (211); the fire outlet gap (d) is connected to the gas channel (212); the guide hole (210) is connected from top to bottom and is provided at a position of the lower cover (21) corresponding to the gas channel (212) and is located above the gap (111); An air supplement cavity (13) is formed between the inner ring gas mixing chamber (110) and the outer ring cavity (12), and at least one air supplement channel (14) for connecting the air supplement cavity (13) and the outside is provided on the base (1); There are at least two air supplement channels (14), which are radially arranged in the outer ring cavity (12) from the center of the air supplement cavity (13); and air inlets (142) of the air supplement channels (14) are formed on the outer peripheral wall of the base (1); The cooker further comprises an annular energy collecting cover (6), the energy collecting cover (6) being located at the periphery of the burner, and the outer peripheral wall of the energy collecting cover (6) is provided with a secondary air inlet (6a) in fluid communication with the air inlet (142) of the air supply channel (14); The secondary air inlet (6a) and the air inlet (142) of the air supply channel (14) are arranged in a staggered manner, and the projection of the air inlet (142) along the centerline direction of the energy gathering cover (6) falls between the two secondary air inlets (6a); The energy gathering cover (6) has a cavity (61) inside, the outer peripheral wall of the energy gathering cover (6) extends downward to form an annular convex wall (64) located below the cavity (61), and the secondary air inlet (6a) is arranged on the annular convex wall (64); Along the airflow path, a guide group (63) is provided between the secondary air inlet (6a) and the air inlet (142); the guide group (63) is provided on the outside of the bottom wall of the cavity (61) and comprises at least one guide plate (631) extending in the circumferential direction; The guide group (63) comprises at least two guide plates (631) arranged at intervals in the radial direction, a guide channel (632) is formed between two adjacent guide plates (631), and the guide channel (632) is in the shape of an arc that bends radially outwards.

Images