Fire grate, burner and water heater

Abstract

The invention discloses a fire grate, a combustor and a water heater, and relates to the technical field of water heaters, the fire grate comprises a fire grate body, the fire grate body is provided with a first air inlet flow channel, a mixing cavity and a fire hole, the first air inlet flow channel is provided with a first air inlet, and the exhaust end of the first air inlet flow channel, the mixing cavity and the fire hole are sequentially communicated; the flow guide part is arranged on the fire grate body, the flow guide part and the fire grate body define a second air inlet flow channel, and the second air inlet flow channel is provided with a second air inlet; the second air inlet flow channel comprises a first flow channel section, a second flow channel section and a third flow channel section which are sequentially arranged from the second air inlet to the mixing cavity, the overflowing sectional area of the first flow channel section is reduced towards the side close to the second flow channel section, and the overflowing sectional area of the second flow channel section is increased towards the side close to the third flow channel section; the third runner section is communicated with the mixing cavity. According to the technical scheme, the air content in the fire grate can be increased, the mixing degree of fuel gas and air is increased, sufficient combustion can be achieved, and the emission amount of nitric oxide in smoke is reduced.

Description

Technical Field

[0001] This invention relates to the field of water heater technology, and in particular to a burner, a burner, and a water heater. Background Technology

[0002] Traditional burners often suffer from insufficient injector air content in the burner grate, and the gas and air do not mix properly during the flow process within the injector and burner grate, ultimately leading to incomplete combustion and excessive emissions of nitrogen oxides and other pollutants in the flue gas. Summary of the Invention

[0003] The main objective of this invention is to propose a burner, a burner, and a water heater, which aims to solve the problem of incomplete combustion and excessive nitrogen oxide emissions in flue gas caused by traditional burners.

[0004] To achieve the above objectives, the present invention provides a fire extinguisher comprising: The burner body includes a first air intake channel, a mixing chamber, and a flame port. The first air intake channel has a first air inlet, and its exhaust end connects to the mixing chamber. The mixing chamber connects to the flame port. The first air inlet is used to supply air and fuel gas to the first air intake channel. A flow guide is disposed on the burner body, and the flow guide and the burner body surround to form a second air intake channel. The second air intake channel has a second air inlet for supplying air to the second air intake channel. The second air intake channel includes a first flow channel section, a second flow channel section, and a third flow channel section arranged sequentially from the second air inlet toward the mixing chamber. The cross-sectional area of ​​the first flow channel section decreases towards the side closer to the second flow channel section, and the cross-sectional area of ​​the second flow channel section increases towards the side closer to the third flow channel section. The third flow channel section communicates with the mixing chamber.

[0005] In one embodiment, the burner body includes a burner plate and two side plates disposed on opposite sides of the burner plate. The burner plate has a plurality of burner holes. The burner plate and the two side plates together define the mixing chamber. The flow guide includes two flow guide plates disposed opposite to each other. The flow guide plates are disposed one-to-one on the side of the side plate away from the mixing chamber. Each flow guide plate and the adjacent side plate surround to form a second air intake channel. Each side plate has a flow guide hole that connects the second air intake channel to the mixing chamber.

[0006] In one embodiment, the guide hole extends from the second air inlet channel toward the mixing chamber and is inclined toward the side closer to the fire orifice plate.

[0007] In one embodiment, the extension direction of the flow guide hole forms a first angle with the thickness direction of the side plate, the first angle being not less than 35° and not greater than 50°.

[0008] In one embodiment, each of the side plates is provided with a plurality of flow guide holes spaced apart along the length of the mixing chamber; And / or, the ratio of the total area of ​​the second air inlet of each second air inlet channel to the total area of ​​the guide holes on the adjacent side plate is not less than 18 and not greater than 22.

[0009] In one embodiment, each of the guide plates includes a main body and a flange bent relative to the main body. The main body is disposed opposite to the side plate. The flange is disposed on the side of the main body near the fire hole plate and bent toward the fire hole plate. The main body, the flange and the side plate surround to form a second air intake channel. The end of the second air intake channel away from the flange is provided with a second air inlet.

[0010] In one embodiment, the main body includes a first plate segment, a second plate segment, and a third plate segment arranged sequentially from the second air inlet toward the flange. The second plate segment is inclined relative to the third plate segment toward the side closer to the side plate, and the first plate segment is inclined relative to the second plate segment toward the side farther from the side plate.

[0011] In one embodiment, the second air inlet is disposed opposite to the flange along a first direction, and the first plate segment is inclined toward the side plate in the direction from the second air inlet toward the flange, and a second included angle is formed between the first plate segment and the first direction, the second included angle being not less than 30° and not greater than 45°.

[0012] In one embodiment, the third plate segment has a protrusion that protrudes toward the side plate.

[0013] In one embodiment, the fire hole plate is located on one side of the fire duct body along the first direction, and the two guide plates are respectively located on opposite sides of the fire duct body along the second direction. Each guide plate has a main body with folded edge plates on both sides along the third direction. The folded edge plates are bent relative to the main body towards the side closer to the fire duct body, and the folded edge plates abut against the outer wall of the fire duct body. The first direction, the second direction, and the third direction are arranged perpendicularly to each other.

[0014] In one embodiment, the flow guide further includes a connecting arm that connects the two flow guide plates. Multiple connecting arms are spaced apart along the length of the fire orifice plate, and the multiple connecting arms abut against the side of the fire orifice plate away from the mixing chamber.

[0015] The present invention also proposes a burner comprising the fire bar as described above.

[0016] The present invention also proposes a water heater, including the burner described above.

[0017] The technical solution of this invention includes a flow guide in the burner body, which has a first air intake channel, a mixing chamber, and a flame port. The first air intake channel has a first air inlet for introducing air and fuel gas. The flow guide and the burner body enclose at least one second air intake channel, which has a second air inlet for introducing air. The exhaust ends of the first and second air intake channels are respectively connected to the mixing chamber, which is connected to the flame port. Furthermore, the second air intake channel includes a first flow channel section, a second flow channel section, and a third flow channel section arranged sequentially from the second air inlet towards the mixing chamber. The cross-sectional area of ​​the first flow channel section decreases towards the side closer to the second flow channel section, and the cross-sectional area of ​​the second flow channel section increases towards the side closer to the third flow channel section. The third flow channel section is connected to the mixing chamber. Thus, when the burner is burning, air (i.e., primary air) and fuel gas are delivered to the mixing chamber through the first air inlet and the first air intake channel to mix and form a gas mixture. Simultaneously, air (i.e., secondary air) is delivered to the mixing chamber through the second air inlet and the second air intake channel to mix again with the gas mixture in the mixing chamber. Finally, the air-fuel mixture in the mixing chamber is delivered to the burner orifice for ignition and combustion. Because the second air intake channel replenishes the mixing chamber with secondary air, it increases the air content in the mixing chamber, thereby increasing the primary air coefficient of the burner. Furthermore, by constructing the second air intake channel with a Venturi-like structure, it enhances air ejection capability, achieving a high-speed jet. This allows the air delivered to the mixing chamber through the second air intake channel to collide and mix with the gas mixture in the mixing chamber, increasing airflow turbulence and thus improving the mixing degree of air and fuel gas, resulting in a more complete mixture. This achieves the dual goals of increasing the primary air coefficient inside the combustor and promoting the mixing of fuel gas and air, ultimately enabling lean premixed combustion of fuel on the combustor. Lean premixed combustion is a technology that premixes fuel with excess air to form a homogeneous lean mixture before combustion. By enabling lean premixed combustion of fuel on the combustor, combustion is more complete, and the combustion temperature is significantly reduced, which can significantly suppress the formation of nitrogen oxides, thereby reducing the amount of nitrogen oxides emitted in the flue gas. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional structural diagram of a fire bar according to an embodiment of the prior art; Figure 2 for Figure 1 Schematic diagram of gas flow path in the middle burner; Figure 3 A schematic diagram of the structure of an embodiment of the fire briquette provided by the present invention; Figure 4 for Figure 3 Cross-sectional view of the center burner; Figure 5 for Figure 4 Schematic diagram of gas flow path in the middle burner; Figure 6 This is a cloud map showing the oxygen mole fraction at the burner hole of a prior art embodiment; Figure 7 An oxygen mole fraction cloud map at the burner hole of a fire briquette according to an embodiment of the present invention; Figure 8 This is a cloud diagram of the oxygen mole fraction of a firebox cross section according to an embodiment of the prior art; Figure 9 An oxygen mole fraction cloud diagram of the firebox cross section provided by an embodiment of the present invention; Figure 10 This is a velocity cloud diagram of the cross-section of the fire hole in a fire bar, according to an embodiment of the prior art. Figure 11 A velocity cloud diagram of the cross-section of the fire hole in a fire bar, provided by an embodiment of the present invention; Figure 12 This is a magnified velocity vector diagram of a fire bar cross-section according to an embodiment of the prior art. Figure 13 This is a magnified velocity vector diagram of a fire bar section according to an embodiment of the present invention.

[0020] Explanation of icon numbers: 101. Inlet air passage; 102. Main burner; 103. Diversion air passage; 104. Diversion hole; 105. Side burner; 11. Flame stabilizer; 200. Flame purlin; 201. First air intake channel; 201a. First air inlet; 2011. Ejector section; 2012. Guide section; 202. Mixing chamber; 203. Flame hole; 204. Second air intake channel; 204a. Second air inlet; 2041. First flow channel section; 2042. Second flow channel section; 2043. Third flow channel section; 2044. Transition flow channel section; 20. Flame purlin body; 21. Flame hole plate; 22. Side plate; 221. Guide hole; 30. Guide component; 31. Guide plate; 311. Main body; 3111. First plate section; 3112. Second plate section; 3113. Third plate section; 3114. Transition plate section; 31131. Protrusion; 312. Flanged edge; 313. Folded edge plate; 32. Connecting arm.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] Currently, the combustion method of household gas water heaters on the market is mainly atmospheric combustion. This method involves mixing the fuel jet with air via a venturi injection system, which then burns the fuel on the burner fins. Therefore, the air content in the burner and the degree of mixing between the gas and air determine its combustion performance and emission performance.

[0026] Traditional burners cannot achieve sufficient combustion by drawing in enough air through the Venturi during fuel jetting. Furthermore, the fuel and air cannot mix well during the flow process within the burner and the jet, resulting in incomplete combustion and excessive emissions of nitrogen oxides and other pollutants in the flue gas.

[0027] like Figure 1 As shown, a burner 200 according to an embodiment of the prior art is provided. The burner 200 includes a burner body 20 and flame stabilizers 11 disposed on both sides of the top of the burner body 20. The burner body 20 has an air inlet duct 101 and a mixing chamber 202. The air inlet duct 101 has an air inlet for introducing air and fuel gas. The exhaust end of the air inlet duct 101 communicates with the mixing chamber 202. The top of the burner body 20 is provided with a main burner port 102 communicating with the mixing chamber 202. A diversion duct 103 is defined between the flame stabilizers 11 and the burner body 20. The burner body 20 is provided with a diversion hole 104 communicating with the mixing chamber 202 and the diversion duct 103. The bottom side of the flame stabilizers 11 is attached to the outer wall of the burner body 20. A side burner port 105 is formed between the top side of the flame stabilizers 11 and the burner body 20. The exhaust end of the diversion duct 103 communicates with the side burner port 105.

[0028] The gas flow path of the firebox 200 in the above embodiment is as follows: Figure 2 As shown, air and fuel gas at the intake port are transported to the mixing chamber 202 via the intake channel 101, where they mix to form a mixture. Part of the mixture in the mixing chamber 202 flows upward to the main burner 102 for combustion, while the other part flows through the diversion hole 104 on the side of the burner body 20 to the diversion channel 103, and then is transported to the side burner 105 for combustion. Secondary air from the external environment can only flow upward along the outer wall of the burner 200 to the side burner 105, and cannot replenish the secondary air inside the burner 200. Due to insufficient primary air intake at the burner 200's intake port and the lack of significant disturbance in the flow of the mixture inside the burner 200, the air content inside the burner 200 is low, and the fuel gas and air cannot be fully mixed, ultimately leading to incomplete combustion and excessive emissions in the flue gas.

[0029] This invention proposes a burner 200 that can increase the air content inside the burner 200 and improve the mixing degree of air and fuel gas inside the burner 200, thereby achieving complete combustion and reducing the emission of nitrogen oxides in the flue gas.

[0030] Please see Figures 3 to 5 In one embodiment of the present invention, the burner 200 includes a burner body 20 and a guide member 30. The burner body 20 is provided with a first air intake channel 201, a mixing chamber 202, and a flame hole 203. The first air intake channel 201 has a first air inlet 201a, and the exhaust end of the first air intake channel 201 is connected to the mixing chamber 202. The mixing chamber 202 is connected to the flame hole 203. The first air inlet 201a is used to supply air and fuel gas to the first air intake channel 201. The guide member 30 is disposed on the burner body 20, and the guide member 30 and the burner body 20 surround to form a second air intake channel 204. The second air intake channel 204 has a second air inlet 204a. The second air inlet 204a is used to supply air to the second air intake channel 204. The second air intake channel 204 includes a first flow channel section 2041, a second flow channel section 2042, and a third flow channel section 2043 arranged sequentially from the second air inlet 204a toward the mixing chamber 202. The cross-sectional area of ​​the first flow channel section 2041 decreases towards the side closer to the second flow channel section 2042, and the cross-sectional area of ​​the second flow channel section 2042 increases towards the side closer to the third flow channel section 2043. The third flow channel section 2043 connects to the mixing chamber 202.

[0031] The burner 200 includes a burner body 20, which constitutes the main structure of the burner 200. The burner body 20 is provided with a first air intake channel 201, a mixing chamber 202, and flame holes 203. The first air intake channel 201 has a first air inlet 201a, which is used to supply fuel gas and air into the first air intake channel 201. The first air intake channel 201 may be at least partially constructed as a Venturi channel, so that the high-speed flow of fuel gas in the first air intake channel 201 generates a local low-pressure zone. The suction generated by the local low-pressure zone draws external air from the first air inlet 201a into the first air intake channel 201, thereby enabling the first air intake channel 201 to supply fuel gas and air. Alternatively, air may be blown into the first air inlet 201a by a fan. The mixing chamber 202 provides a place for mixing air and fuel gas. The flame holes 203 are used to output the mixture of air and fuel gas in the mixing chamber 202 for combustion. Multiple flame holes 203 are usually provided, and the multiple flame holes 203 are arranged at intervals along the length of the flame bar body 20 to increase the combustion area.

[0032] The burner 200 also includes a guide member 30 disposed on the burner body 20. The guide member 30 is connected to the burner body 20 by methods including but not limited to welding, fastener connection, snap-fit, and plug-in; alternatively, the guide member 30 and the burner body 20 can be constructed as an integral structure. The guide member 30, together with the burner body 20, defines a second air intake channel 204. The number of second air intake channels 204 is not limited; there can be one, two, or more. The air intake end of the second air intake channel 204 is provided with a second air inlet 204a for introducing air, and the exhaust end of the second air intake channel 204 connects to the mixing chamber 202. This allows external air to be delivered to the second air intake channel 204 via the second air inlet 204a, and then to the mixing chamber 202 via the second air intake channel 204.

[0033] like Figure 5 As shown, in this embodiment, the gas flow path of the burner 200 is as follows: When the burner 200 is burning, air (i.e., primary air) and fuel gas are transported to the mixing chamber 202 through the first air inlet 201a and the first air intake channel 201 to mix and form a mixed gas. At the same time, air (i.e., secondary air) is transported to the mixing chamber 202 through the second air inlet 204a and the second air intake channel 204 to form a counter-mixing with the mixed gas in the mixing chamber 202. Finally, the air and fuel gas mixture in the mixing chamber 202 is transported to the burner hole 203 for ignition and combustion.

[0034] Air at the second air inlet 204a is sequentially transported through the first flow channel section 2041, the second flow channel section 2042, and the third flow channel section 2043 into the mixing chamber 202. The cross-sectional area of ​​the first flow channel section 2041 decreases towards the side closer to the second flow channel section 2042, while the cross-sectional area of ​​the second flow channel section 2042 increases towards the side closer to the third flow channel section 2043, making the second air intake channel 204 structure similar to a Venturi channel. When air passes through the first flow channel section 2041, the air velocity gradually increases within the first flow channel section 2041, and a low-pressure zone is formed at the end of the first flow channel section 2041. When the pressure at the second air inlet 204a is greater than the pressure of the low-pressure zone at the end of the first flow channel section 2041, the pressure difference allows air from the external environment to be drawn into the second air intake channel 204 through the second air inlet 204a, increasing the amount of air entering. As air passes through the second flow channel section 2042, its velocity gradually decreases and its pressure gradually recovers, which helps to reduce mechanical energy loss and ensure ejection capability. Thus, by constructing the second inlet flow channel 204 as a Venturi-like structure, it is beneficial to enhance air ejection capability and achieve high-speed jets, allowing the air transported through the second inlet flow channel 204 to be mixed with the mixed gas in the mixing chamber 202.

[0035] The technical solution of the present invention is provided with a guide member 30 in the burner body 20, and the burner body 20 is provided with a first air intake channel 201, a mixing chamber 202 and a flame hole 203. The first air intake channel 201 has a first air inlet 201a for introducing air and fuel gas. The guide member 30 and the burner body 20 surround to form a second air intake channel 204. The second air intake channel 204 has a second air inlet 204a for introducing air. The exhaust end of the first air intake channel 201 and the exhaust end of the second air intake channel 204 are respectively connected to the mixing chamber 202, and the mixing chamber 202 is connected to the flame hole 203. Thus, when the burner 200 is burning, air (i.e., primary air) and fuel gas are delivered to the mixing chamber 202 through the first air inlet 201a and the first air intake channel 201, where they mix to form a gas mixture. Simultaneously, air (i.e., secondary air) is delivered to the mixing chamber 202 through the second air inlet 204a and the second air intake channel 204, where it is counter-mixed with the gas mixture in the mixing chamber 202. Finally, the gas mixture of air and fuel gas in the mixing chamber 202 is delivered to the burner hole 203 for ignition and combustion. Because the second air intake channel 204 supplies secondary air to the mixing chamber 202, it increases the air content within the mixing chamber 202, thereby increasing the primary air coefficient of the combustor 200. Furthermore, by constructing the second air intake channel 204 as a Venturi-like flow channel, it enhances air ejection capability, enabling high-speed jetting. During the air delivery process to the mixing chamber 202, the second air intake channel 204 can collide and mix with the mixed air within the mixing chamber 202, increasing airflow turbulence and thus improving the mixing degree of air and fuel gas within the mixing chamber 202, resulting in more thorough mixing. This achieves the dual objectives of increasing the primary air coefficient inside the combustor 200 and promoting fuel-air mixing, ultimately achieving lean premixed combustion of fuel on the combustor 200. Lean premixed combustion is a technology that premixes fuel with excess air to form a homogeneous lean mixture before combustion. By enabling the fuel to undergo lean premixed combustion on the burner 200, the combustion of the fuel is more complete, and the combustion temperature can be significantly reduced, which can significantly suppress the formation of nitrogen oxides, thereby reducing the amount of nitrogen oxides emitted in the flue gas.

[0036] like Figure 3As shown, optionally, the burner body 20 has a first side and a second side opposite to each other along its length. A first air inlet 201a is provided near the bottom of the first side of the burner body 20. The burner body 20 internally forms a first air intake channel 201 and a mixing chamber 202. The top of the burner body 20 has a plurality of flame holes 203 spaced apart along its length. The first air intake channel 201 may include an ejector section 2011 and a guide section 2012. The ejector section 2011 extends from the first air inlet 201a toward the second side of the burner body 20. The guide section 2012 bends from the end of the ejector section 2011 away from the first air inlet 201a toward the top of the burner body 20 and extends toward the first side of the burner body 20. The mixing chamber 202 is located at the top of the guide section 2012. Thus, the air and fuel gas at the first air inlet 201a are transported to the guide section 2012 via the ejector section 2011, and then to the mixing chamber 202 via the guide section 2012. Since the ejector section 2011 and the guide section 2012 extend in different directions, it is beneficial to extend the flow path of the gas without increasing the volume of the burner body 20, so that the fuel gas and air can be initially mixed in the first air inlet channel 201 before being transported to the mixing chamber 202 for further mixing, thereby enhancing the degree of gas mixing.

[0037] Optionally, the ejector section 2011 includes a converging section and a diverging section arranged sequentially along the air intake direction. The cross-sectional area of ​​the converging section decreases from the first air intake 201a toward the diverging section, while the cross-sectional area of ​​the diverging section increases from the converging section toward the direction away from the first air intake 201a. This makes the ejector section 2011 a Venturi channel. As the gas passes through the converging section, the gas velocity gradually increases, and a low-pressure zone can be formed at the end of the converging section. When the pressure at the first air intake 201a is greater than the pressure in the low-pressure zone at the end of the converging section, the pressure difference allows air from the external environment to be drawn into the first air intake channel 201 through the first air intake 201a. As the gas passes through the diverging section, the velocity gradually decreases, and the pressure gradually recovers. The diverging section helps reduce mechanical energy loss and ensures ejection capability. In this way, when the first intake channel 201 delivers gas and air, the gas and air can be fully mixed, thereby improving the uniformity of the gas-air mixture when the first intake channel 201 is inlet.

[0038] Optionally, the maximum flow cross-sectional area of ​​the second flow channel section 2042 is smaller than the flow cross-sectional area of ​​the second air inlet 204a, and the maximum flow cross-sectional area of ​​the third flow channel section 2043 is smaller than the flow cross-sectional area of ​​the second air inlet 204a. This results in a relatively large flow cross-sectional area at the second air inlet 204a, ensuring a larger airflow area at the second air inlet 204a and increasing the amount of air entering the second air intake channel 204. After being accelerated through the first flow channel section 2041, the air enters the second flow channel section 2042 and the third flow channel section 2043. Since the cross-sectional area of ​​the second flow channel section 2042 and the third flow channel section 2043 is smaller than that of the second air inlet 204a, the gas velocity in the second flow channel section 2042 and the third flow channel section 2043 can still be higher than that at the second air inlet 204a. This allows the air to flow into the mixing chamber 202 at a higher velocity, so as to counteract and mix with the mixed gas in the mixing chamber 202, thereby improving the mixing uniformity. Optionally, a transition flow section 2044 is provided between the first flow section 2041 and the second flow section 2042. The cross-sectional area of ​​the transition flow section 2044 decreases from the side closer to the first flow section 2041 to the side closer to the second flow section 2042. In this way, the air accelerated in the first flow section 2041 can be accelerated again through the transition flow section 2044 before entering the second flow section 2042, further enhancing the jetting capability.

[0039] like Figure 3 and Figure 4 As shown, in one embodiment, the burner body 20 includes a burner plate 21 and two side plates 22 disposed on opposite sides of the burner plate 21. The burner plate 21 is provided with a plurality of burner holes 203. The burner plate 21 and the two side plates 22 together define a mixing chamber 202. The flow guide 30 includes two flow guide plates 31 disposed opposite to each other. The flow guide plates 31 are disposed one-to-one on the side of the side plate 22 away from the mixing chamber 202. Each flow guide plate 31 and the adjacent side plate 22 surround to form a second air intake channel 204. Each side plate 22 is provided with a flow guide hole 221 that connects the second air intake channel 204 and the mixing chamber 202.

[0040] In this embodiment, the burner body 20 includes a perforated plate 21 and two side plates 22 disposed on both sides of the perforated plate 21. The perforated plate 21 may be disposed on one side in the height direction of the burner body 20, and the two side plates 22 may be disposed on both sides in the width direction of the perforated plate 21. The perforated plate 21 extends along the length direction of the burner body 20 and has a plurality of perforations 203 spaced apart along its length direction. The perforated plate 21 may be integrally formed with the two side plates 22, or the perforated plate 21 may be connected to the side plates 22 by welding, riveting, fastener connection, etc. For example, in practical applications, the perforated plate 21 and the two side plates 22 may be integrally bent from sheet metal, and the edges of the two side plates 22 may be welded and fixed so that the perforated plate 21 and the two side plates 22 surround to form a first air intake channel 201 and a mixing chamber 202. Typically, the orifice plate 21 is located at the top of the burner body 20, and correspondingly, the mixing chamber 202 is located on the burner body 20 near the orifice plate 21.

[0041] The flow guide 30 includes two flow guide plates 31 arranged opposite each other. The flow guide plates 31 are arranged one-to-one on the side of the side plate 22 away from the mixing chamber 202. Each flow guide plate 31 and the adjacent side plate 22 form a second air intake channel 204. Each side plate 22 is provided with a flow guide hole 221 that connects the second air intake channel 204 to the mixing chamber 202. In this way, the opposite sides of the burner body 20 are respectively provided with second air intake channels 204. Each second air intake channel 204 can deliver air into the mixing chamber 202 through the flow guide hole 221 on the adjacent side plate 22, thereby further increasing the air delivery volume and making it more beneficial to increase the air content in the mixing chamber 202. Furthermore, by simultaneously supplying air into the mixing chamber 202 through the second air intake channels 204 on both sides of the burner body 20, the air distribution in the mixing chamber 202 becomes more uniform, which helps to further improve the uniformity of air mixing with the mixture in the mixing chamber 202. At the same time, it can also avoid the uneven temperature distribution in the mixing chamber 202 that would have an adverse effect on combustion completeness if only one side of the second air intake channel 204 supplies air into the mixing chamber 202.

[0042] It is worth noting that the two guide plates 31 of the flow guide 30 can be set separately, or they can be connected as one unit by a connecting structure (such as a connecting arm 32), as long as each side plate 22 has a guide plate 31 on its outer side. For example, when the two guide plates 31 are set separately, they can be welded to the corresponding side plate 22 respectively. When the two guide plates 31 are connected together by the connecting arm 32, the connecting arm 32 can be directly attached to the top surface of the fire hole plate 21, so that the two guide plates 31 are placed on both sides of the fire bar body 20. This eliminates the welding step and simplifies the assembly process. The cross-sectional shape of the flow holes 221 on the side plate 22 includes, but is not limited to, circular, elliptical, rectangular or other irregular cross-sections. The number of flow holes 221 on each side plate 22 can be one, two or more, and is not specifically limited here.

[0043] Understandably, the flow cross-sectional area of ​​the guide hole 221 on the side plate 22 is relatively small compared to the second air inlet channel 204. Thus, when air enters the relatively small flow cross-sectional area of ​​the guide hole 221 from a larger space, a high-speed jet is generated. This facilitates the air in the second air inlet channel 204 flowing towards the mixing chamber 202 at a higher velocity, forming a high-speed opposing mixing with the mixed gas in the mixing chamber 202. This further enhances the gas turbulence within the mixing chamber 202 and improves the uniformity of gas mixing within the mixing chamber 202.

[0044] Furthermore, such as Figure 4 As shown, in one embodiment, the guide hole 221 extends from the second air inlet channel 204 toward the mixing chamber 202 and is inclined toward the side near the flame orifice plate 21. By setting the guide hole 221 as an oblique hole, with the outlet end of the guide hole 221 facing the flame orifice plate 21, air in the second air inlet channel 204 can be obliquely ejected upward through the inclined guide hole 221 to the side of the mixing chamber 202 near the flame orifice plate 21. By setting the inclined guide hole 221, on the one hand, it is beneficial to guide the air to move towards the side closer to the flame plate 21 to the flame hole 203 to achieve secondary air replenishment, so as to ensure the air content at the flame hole 203 and facilitate complete combustion; on the other hand, if the guide holes 221 on the two side plates 22 directly face each other for air jetting, or if the guide holes 221 on the two side plates 22 are both inclined downwards for air jetting, it will generate greater resistance to the gas in the incoming flow direction, thereby blocking the normal path of the mixed gas in the mixing chamber 202 towards the flame hole 203, which may cause the flame hole 203 to be extinguished due to insufficient gas supply. By designing the guide hole 221 to be inclined upwards towards the side closer to the flame plate 21, the airflow resistance can be reduced and the flameout can be prevented.

[0045] It is understandable that the extension direction of the guide hole 221 forms a first angle α with the thickness direction of the side plate 22. If the angle α is too small, the inclination angle of the guide hole 221 relative to the thickness direction of the side plate 22 will be too small, and the guide hole 221 will tend to extend laterally along the thickness direction of the side plate 22. In this case, the airflow ejected from the guide hole 221 will directly impact the opposite side plate 22 and will not be able to guide the airflow to the fire orifice plate effectively. If the angle α is too large, the inclination angle of the guide hole 221 relative to the thickness direction of the side plate 22 will be too large, and the airflow ejected from the guide hole 221 will flow closer to the side plate 22 on its own side and will not be able to form a good counter-mixing with the mixed gas in the center of the mixing chamber 202, thus affecting the mixing effect.

[0046] Optionally, the extension direction of the guide hole 221 forms a first angle with the thickness direction of the side plate 22, the first angle being not less than 35° and not greater than 50°. That is, the extension direction of the guide hole 221 and the thickness direction of the side plate 22 form a first angle α, satisfying 35°≤α≤50°. This makes the first angle α moderate, which is beneficial for guiding air towards the flame orifice plate through the inclined guide hole 221 to replenish the flame orifice 203 at the flame orifice plate, and also for guiding air towards the center of the mixing chamber 202 to form a counter-mixing with the mixed air in the center of the mixing chamber 202, thus improving the mixing effect. This is more conducive to increasing the air content and mixing uniformity, ensuring complete combustion, and reducing the emission of nitrogen oxides in the flue gas. For example, the first included angle α can be 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, or any angle within the above range.

[0047] To further improve the air content and gas mixing uniformity within the mixing chamber 202, in some embodiments, each side plate 22 is provided with a plurality of guide holes 221 spaced apart along the length of the mixing chamber 202. And / or, the ratio of the total area of ​​the second air inlet 204a of each second air inlet channel 204 to the total area of ​​the guide holes 221 on the adjacent side plate 22 is not less than 18 and not greater than 22.

[0048] In one embodiment, each side plate 22 is provided with a plurality of guide holes 221 spaced apart along the length of the mixing chamber 202. For example, the mixing chamber 202 extends along the length of the burner body 20, and each side plate 22 is provided with a plurality of guide holes 221, which are spaced apart along the length of the mixing chamber 202. In this way, the air delivered by the second air intake channel 204 can be simultaneously ejected into the mixing chamber 202 through the plurality of guide holes 221 on the side plate 22, increasing the air content entering the mixing chamber 202 at a time. Furthermore, the plurality of guide holes 221 are spaced apart along the length of the mixing chamber 202, which enables multi-point jetting, so that the mixing chamber 202 has a high air content at various parts along its length, and achieves multi-point counter-mixing with the mixed gas in the mixing chamber 202, which is more conducive to improving the overall air content and gas mixing uniformity of the mixing chamber 202, thereby making the combustion more complete. Furthermore, with the total area of ​​the guide hole 221 remaining unchanged, the guide hole 221 with a large opening area is dispersed into multiple guide holes 221 with relatively small opening areas, making the opening area of ​​the individual guide hole 221 smaller, which is more conducive to achieving high-speed jet through the guide hole 221, thereby further enhancing the degree of disturbance to the air in the mixing chamber 202 and further improving the mixing uniformity.

[0049] In one embodiment, the ratio of the total area of ​​the second air inlet 204a of each second air inlet channel 204 to the total area of ​​the guide holes 221 on the adjacent side plate 22 is not less than 18 and not greater than 22. That is, the total area of ​​the second air inlet 204a of each second air inlet channel 204 is S1, and the total area of ​​all guide holes 221 on the side plate 22 adjacent to the second air inlet channel 204 is S2, satisfying: 18≤S1 / S2≤22. In this way, the total area of ​​the second air inlet 204a is relatively large, which is beneficial to increasing the air content entering the second air inlet channel 204 through the second air inlet 204a. Furthermore, the total area of ​​all the guide holes 221 on the side plate 22 adjacent to the second air intake channel 204 is smaller than the total area of ​​the second air intake port 204a. This causes the air in the second air intake channel 204 to be accelerated when it enters the guide holes 221, thereby achieving a high-speed jet. This is beneficial for further enhancing the counter-mixing effect with the mixed gas in the mixing chamber 202, improving the mixing degree and mixing uniformity. For example, S1 / S2 can be 18, 19, 20, 21, 22, or any value within the above range.

[0050] like Figure 3 and Figure 4As shown, in one embodiment, each guide plate 31 includes a main body 311 and a flange 312 bent relative to the main body 311. The main body 311 is disposed opposite to the side plate 22. The flange 312 is disposed on the side of the main body 311 near the fire hole plate 21 and bent toward the fire hole plate 21. The main body 311, the flange 312 and the side plate 22 surround to form a second air intake channel 204. The end of the second air intake channel 204 away from the flange 312 is provided with a second air inlet 204a.

[0051] In this embodiment, the top of the main body 311 is provided with a flange 312, which is roughly flush with the flame plate 21. The main body 311, flange 312, and side plate 22 form a second air intake channel 204. The end of the second air intake channel 204 away from the flange 312 is provided with a second air inlet 204a. The flange 312 can block the end of the second air intake channel 204 away from the second air inlet 204a, so that the air in the second air intake channel 204 can only enter the mixing chamber 202 through the guide hole 221 on the side plate 22 of the burner body 20. This can increase the air content entering the mixing chamber 202 from the second air intake channel 204, making the combustion more complete and further reducing the nitrogen and oxygen emission content in the flue gas.

[0052] Furthermore, such as Figure 4 As shown, in one embodiment, the main body 311 includes a first plate segment 3111, a second plate segment 3112 and a third plate segment 3113 arranged sequentially from the second air inlet 204a toward the flange 312. The second plate segment 3112 is inclined toward the side closer to the side plate 22 relative to the third plate segment 3113, and the first plate segment 3111 is inclined toward the side away from the side plate 22 relative to the second plate segment 3112.

[0053] In this embodiment, the third plate segment 3113 extends downward from the side of the flange 312 away from the fire hole plate 21. The second plate segment 3112 bends downward from the bottom side of the third plate segment 3113 toward the side plate 22 and extends downward at an angle. The first plate segment 3111 bends downward from the bottom side of the second plate segment 3112 toward the side plate 22 and extends downward at an angle. A first flow channel segment 2041 is formed between the first plate segment 3111 and the side plate 22, a second flow channel segment 2042 is formed between the second plate segment 3112 and the side plate 22, and a third flow channel segment 2043 is formed between the third plate segment 3113 and the side plate 22. The second air inlet 204a, the first flow channel segment 2041, the second flow channel segment 2042, and the third flow channel segment 2043 are sequentially connected to form a second air inlet channel 204.

[0054] Because the first plate segment 3111 is inclined relative to the second plate segment 3112 towards the side away from the side plate 22, the flow cross-sectional area of ​​the first flow channel segment 2041 decreases towards the side closer to the second flow channel segment 2042. When air passes through the first flow channel segment 2041, the air velocity gradually increases within the first flow channel segment 2041, and a low-pressure zone is formed at the end of the first flow channel segment 2041. When the pressure at the second air inlet 204a is greater than the pressure in the low-pressure zone at the end of the first flow channel segment 2041, the pressure difference allows air from the external environment to be drawn into the second intake flow channel 204 through the second air inlet 204a, increasing the amount of air entering. Furthermore, by inclining the first plate segment 3111 relative to the second plate segment 3112 towards the side away from the side plate 22, the first flow channel segment 2041 is widened, resulting in a larger opening area for the second air inlet 204a, which further facilitates air entering the second intake flow channel 204. In addition, the first plate segment 3111 is set as an outwardly flared inclined plate body, so that the inner wall surface of the first plate segment 3111 forms an inclined flow guide surface, which can guide the air in the first flow channel segment 2041 to flow towards the side closer to the side plate 22, so that the air can flow along the side plate 22 to the flow guide hole 221, and be jetted into the mixing chamber 202 through the flow guide hole 221.

[0055] Because the second plate segment 3112 is inclined towards the side plate 22 relative to the third plate segment 3113, the cross-sectional area of ​​the second flow channel segment 2042 is increased towards the side closer to the third flow channel segment 2043. When air passes through the second flow channel segment 2042, the air velocity gradually decreases and the pressure gradually recovers, which helps to reduce mechanical energy loss and ensure ejection capability. Thus, by constructing the second inlet air channel 204 as a Venturi-like flow channel structure, it is beneficial to enhance the air ejection capability and achieve high-speed jet, so that the air transported through the second inlet air channel 204 can be mixed with the mixed air in the mixing chamber 202, thereby improving the mixing degree and mixing uniformity.

[0056] Optionally, the main body 311 further includes a transition plate section 3114 disposed between the first plate section 3111 and the second plate section 3112. The transition plate section 3114 and the side plate 22 form a transition flow channel section 2044, which connects the first flow channel section 2041 and the second flow channel section 2042. Optionally, the flow cross-sectional area of ​​the transition flow channel section 2044 decreases from the side closer to the first flow channel section 2041 to the side closer to the second flow channel section 2042. In this way, the air accelerated in the first flow channel section 2041 can be accelerated again through the transition flow channel section 2044 before entering the second flow channel section 2042, further improving the jetting capability.

[0057] The second air inlet 204a and the flange 312 are arranged opposite each other along the first direction. The first plate segment 3111 is inclined towards the side plate 22 in the direction from the second air inlet 204a toward the flange 312, forming a second angle between the first plate segment 3111 and the first direction. It is understandable that if the second angle is too small, the opening area of ​​the second air inlet 204a will be too small, resulting in relatively large flow resistance at the second air inlet 204a, which is not conducive to guiding external air into the first flow channel segment 2041 through the second air inlet 204a. If the second angle is too large, it can easily lead to flow separation and an uneven flow field, thus severely reducing the ejection efficiency. Optionally, the second angle is not less than 30° and not greater than 45°. That is, the angle formed between the first plate segment 3111 and the first direction is the second angle β, satisfying: 30°≤β≤45°. This makes the second included angle β moderate, which is beneficial to improving the ejection efficiency of the second intake channel 204, allowing more external air to enter the second intake channel 204 through the second air inlet 204a, thereby increasing the air content and mixing degree within the combustor 200. For example, the second included angle β can be 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°, 45°, or any angle value within the above range.

[0058] like Figure 3 As shown, in one embodiment, the third plate segment 3113 is provided with a protrusion 31131 protruding towards the side plate 22. This results in a smaller flow area in the third flow channel segment 2043 corresponding to the location of the protrusion 31131, which helps to increase the air velocity. This allows the air in the third flow channel segment 2043 to flow towards the guide hole 221 at a higher speed, achieving high-speed jetting. This further enhances the disturbance to the gas in the mixing chamber 202 and improves the mixing uniformity. Optionally, the third plate segment 3113 is provided with multiple protrusions 31131 spaced apart along the length of the burner body 20, and the side plate 22 is provided with multiple guide holes 221 spaced apart along the length of the burner body 20. The protrusions 31131 and guide holes 221 are arranged one-to-one opposite each other, so that each guide hole 221 can achieve high-speed jetting. In practical applications, a convex bulge 31131 can be formed by stamping the outer surface of the guide plate 31 toward the side plate 22, which can simplify the manufacturing process and improve production efficiency.

[0059] like Figure 3As shown, in one embodiment, the fire hole plate 21 is located on one side of the fire duct body 20 along the first direction, and the two guide plates 31 are respectively located on opposite sides of the fire duct body 20 along the second direction. Each guide plate 31 has a main body 311 with a folded edge plate 313 on both sides along the third direction. The folded edge plate 313 is bent relative to the main body 311 towards the side closer to the fire duct body 20, and the folded edge plate 313 abuts against the outer wall of the fire duct body 20. The first direction, the second direction and the third direction are arranged perpendicularly to each other.

[0060] In this embodiment, the first direction can be the height direction of the burner body 20, the second direction can be the width direction of the burner body 20, and the third direction can be the length direction of the burner body 20. The burner plate 21 is located at the top of the burner body 20, and two guide plates 31 are respectively located on both sides of the burner body 20 in the width direction and are disposed close to the burner plate 21. The main body 311 of each guide plate 31 defines a second air intake channel 204 between itself and the burner body 20. Each main body 311 has a flange 312 on its top and folded plates 313 on both sides along the length of the burner body 20. The flange 312 is connected to the burner plate 21 and can block the top of the second air intake channel 204. The folded plates 313 are in contact with the outer wall of the burner body 20 and can block both sides of the second air intake channel 204 along the length of the burner body 20. This ensures that the air in the second air intake channel 204 can enter the mixing chamber 202 through the guide hole 221 on the side plate 22 as much as possible, thereby increasing the air content and gas mixing degree in the mixing chamber 202.

[0061] like Figure 3 As shown, in one embodiment, the flow guide 30 further includes a connecting arm 32 that connects the two flow guide plates 31. Multiple connecting arms 32 are spaced apart along the length direction of the fire hole plate 21, and multiple connecting arms 32 abut against the side of the fire hole plate 21 away from the mixing chamber 202.

[0062] In this embodiment, the flow guide 30 includes two flow guide plates 31 arranged opposite to each other and spaced apart, and a connecting arm 32 disposed between the two flow guide plates 31. Thus, during assembly, the flow guide 30 can be fastened as a whole to the top of the burner body 20 from top to bottom until the connecting arm 32 abuts against the side of the flame perforation plate 21 away from the mixing chamber 202. The two flow guide plates 31 are positioned on both sides of the burner body 20, and the flame perforation plate 21 supports the connecting arm 32, thereby supporting the flow guide 30. This eliminates the need for other methods (such as welding, riveting, etc.) to fix the flow guide 30, enabling rapid assembly and disassembly of the flow guide 30. Furthermore, multiple connecting arms 32 are spaced apart along the length of the flame perforation plate 21, further improving the connection stability between the two flow guide plates 31 and enhancing the assembly reliability of the flow guide 30 and the burner body 20. Optionally, the flow guide 30 is constructed as a single-piece structure. For example, the flow guide 30 can be integrally formed from sheet metal parts through processes such as bending and punching to form two flow guide plates 31, and a connecting arm 32 connecting the two flow guide plates 31.

[0063] Please combine Figures 6 to 13 ,Will Figure 1 The fire grill 200 (hereinafter referred to as the prior art fire grill 200) shown in the prior art embodiment is similar to... Figure 3 The simulation results cloud map is obtained by simulating the fire duct 200 (hereinafter referred to as the novel fire duct 200) of an embodiment provided in this application. Figure 6 A cloud map showing the oxygen mole fraction at 200 fire holes in an existing firebox. Figure 7 Oxygen mole fraction cloud map at the 200 flame holes of the new type of fire bar; Figure 8 Oxygen mole fraction cloud map for a 200 section of the existing firebox; Figure 9 Oxygen mole fraction cloud map for a novel 200mm cross-section firebox; Figure 10 Velocity contour plot of the existing 200 fire hole cross section; Figure 11 Velocity cloud diagram of the cross-section of the 200 fire hole in the new type of fire bar; Figure 12 A magnified velocity vector diagram of a section of the existing 200mm fire bar; Figure 13 A magnified vector diagram of the velocity of a section of the new type of fire extinguisher with a cross-section of 200mm.

[0064] according to Figures 6 to 9 It can be seen that the oxygen mole fraction at the fire holes and cross-section of the new type 200 fire grate is significantly higher than that of the existing type 200 fire grate. According to... Figures 10 to 13 It can be seen that the jet velocity at the flame holes of the new type of burner 200 is significantly greater than that of the existing burner 200. Its average jet velocity precisely matches the laminar flame propagation velocity of methane at an equivalence ratio of 1, which is beneficial to combustion stability. Furthermore, according to... Figure 12 and Figure 13It can be seen that the velocity distribution at the burner holes of the new type of burner 200 is more stable and uniform, with no significant differences and no large vortices, which is conducive to stable flame combustion. Therefore, the technical solution of the present invention expands the secondary air flow channel (i.e., the second air inlet channel 204) by providing a guide plate 31 on the burner body 20, so that it can be mixed with the gas in the mixing chamber 202 at the upper part of the burner 200, thereby achieving the dual purpose of improving the primary air coefficient inside the burner 200 and promoting the mixing of gas and air. This enables lean premixed combustion of gas in the burner of the burner 200, giving the gas water heater good combustion and emission characteristics during operation.

[0065] The present invention also proposes a burner comprising a flame bar 200. The specific structure of the flame bar 200 is as described in the above embodiments. Since this burner adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here. The burner may include a frame and flame bars 200 disposed within the frame. Multiple flame bars 200 may be arranged side by side.

[0066] This invention also proposes a water heater, including the burner described above. The specific structure of the burner is as described in the above embodiments. Since this water heater adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here. This water heater includes, but is not limited to, forced-draft gas water heaters and forced-extraction gas water heaters.

[0067] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A fire grill, characterized in that, include: The burner body is provided with a first air intake channel, a mixing chamber and a flame hole. The first air intake channel has a first air inlet. The exhaust end of the first air intake channel is connected to the mixing chamber. The mixing chamber is connected to the flame hole. The first air inlet is used to supply air and fuel gas to the first air intake channel. as well as A flow guide is disposed on the burner body, and the flow guide and the burner body surround to form a second air intake channel. The second air intake channel has a second air inlet for supplying air to the second air intake channel. The second air intake channel includes a first flow channel section, a second flow channel section, and a third flow channel section arranged sequentially from the second air inlet toward the mixing chamber. The cross-sectional area of ​​the first flow channel section decreases towards the side closer to the second flow channel section, and the cross-sectional area of ​​the second flow channel section increases towards the side closer to the third flow channel section. The third flow channel section communicates with the mixing chamber.

2. The fire grill as described in claim 1, characterized in that, The fire vent body includes a fire hole plate and two side plates disposed on opposite sides of the fire hole plate. The fire hole plate has a plurality of fire holes. The fire hole plate and the two side plates together define the mixing chamber. The flow guide includes two flow guide plates disposed opposite to each other. The flow guide plates are disposed one-to-one on the side of the side plate away from the mixing chamber. Each flow guide plate and the adjacent side plate surround to form a second air intake channel. Each side plate has a flow guide hole that connects the second air intake channel to the mixing chamber.

3. The fire grill as described in claim 2, characterized in that, The guide hole extends from the second air intake channel toward the mixing chamber and is inclined toward the side closer to the fire orifice plate.

4. The fire grill as described in claim 3, characterized in that, The extension direction of the flow guide hole forms a first angle with the thickness direction of the side plate, and the first angle is not less than 35° and not greater than 50°.

5. The fire grill as described in claim 2, characterized in that, Each of the side plates is provided with a plurality of flow guide holes spaced apart along the length of the mixing chamber; And / or, the ratio of the total area of ​​the second air inlet of each second air inlet channel to the total area of ​​the guide holes on the adjacent side plate is not less than 18 and not greater than 22.

6. The fire grill as described in claim 2, characterized in that, Each of the aforementioned guide plates includes a main body and a flange bent relative to the main body. The main body is disposed opposite to the side plate. The flange is disposed on the side of the main body near the fire hole plate and bent toward the fire hole plate. The main body, the flange, and the side plate surround to form a second air intake channel. The second air intake channel is provided at the end away from the flange.

7. The fire grill as described in claim 6, characterized in that, The main body includes a first plate segment, a second plate segment, and a third plate segment arranged sequentially from the second air inlet toward the flange. The second plate segment is inclined relative to the third plate segment toward the side closer to the side plate, and the first plate segment is inclined relative to the second plate segment toward the side farther away from the side plate.

8. The fire briquette as described in claim 7, characterized in that, The second air inlet is disposed opposite to the flange along the first direction. The first plate segment is inclined toward the side plate in the direction from the second air inlet toward the flange. The first plate segment forms a second angle with the first direction. The second angle is not less than 30° and not greater than 45°.

9. The fire grill as described in claim 7, characterized in that, The third plate segment is provided with a protrusion that protrudes toward the side plate.

10. The fire briquette as described in claim 6, characterized in that, The fire hole plate is located on one side of the fire duct body along the first direction, and the two guide plates are respectively located on opposite sides of the fire duct body along the second direction. Each guide plate has a main body with a folded edge plate on both sides along the third direction. The folded edge plate is bent relative to the main body towards the side closer to the fire duct body, and the folded edge plate abuts against the outer wall of the fire duct body. The first direction, the second direction, and the third direction are arranged perpendicularly to each other.

11. The fire briquette as described in any one of claims 2 to 10, characterized in that, The flow guide further includes a connecting arm that connects the two flow guide plates. Multiple connecting arms are spaced apart along the length of the fire orifice plate, and multiple connecting arms abut against the side of the fire orifice plate away from the mixing chamber.

12. A burner, characterized in that, Includes the fire rack as described in any one of claims 1 to 11.

13. A water heater, characterized in that, Includes the burner as described in claim 12.

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