A new type of dense and thin combustion fire grate, burner and water heater

Abstract

The present invention relates to a novel rich-lean combustion fire grate, burner and water heater. The fire grate comprises a core shell and an inner shell. The side wall of the diversion chamber of the core shell is provided with a rich combustion outlet structure and a lean combustion outlet structure. The inner shell cover comprises an air intake chamber, a lean combustion mixing chamber, a plurality of air guide structures and a rich combustion flame hole structure provided on the side wall of the inner shell. The plurality of air guide structures are in contact and conduction with the plurality of rich combustion outlet structures in a one-to-one correspondence. The air intake chamber cover forms an air intake gap outside the diversion chamber and outside the side wall of the diversion chamber. The combustion top surface of the lean combustion mixing chamber is provided with a lean combustion hole. A rich combustion outlet gap open upward is formed between the inner shells of adjacent fire grates arranged side by side, and a rich combustion hole is formed on the top through the rich combustion flame hole structure. Through the mutual cooperation between the fire grates, lean combustion is achieved on each fire grates, and rich combustion is achieved between the fire grates. The rich and lean flames are spaced apart, which saves the assembly parts of the fire grates and reduces the cost.

Description

Technical Field

[0001] The present invention relates to a water heater, a thick-lean burner and a fire grate thereof, in particular to a water heater, a thick-lean burner and a fire grate thereof which can significantly reduce nitrogen oxide emissions and stabilize flames. Background Art

[0002] Nitrogen oxides are produced when mineral fuels (such as oil, coal, natural gas, etc.) burn with oxygen at high temperatures. x It is a highly toxic gas. my country has formulated emission standards for nitrogen oxides from civilian gas appliances. Manufacturers attach great importance to the production of nitrogen oxides in the design and production of gas appliances.

[0003] Rich-lean combustion is an effective combustion technology that can significantly reduce nitrogen oxide emissions. Research has shown that the air coefficient significantly affects the amount of nitrogen oxides produced in combustion products. Low or high air coefficients result in lower nitrogen oxide levels. Specifically, when the air coefficient is low, such as less than 0.6, insufficient air supply leads to low combustion temperatures and low oxygen content in the combustion zone, suppressing nitrogen oxide production. When the air coefficient is high, significantly exceeding 1.0, such as above 1.4, there is an oversupply of air. While this excess air increases the oxygen concentration in the combustion zone, it also removes a significant amount of heat from the combustion zone, lowering the combustion temperature. This lower combustion temperature also helps suppress nitrogen oxide production. Combustion with a low air coefficient is called rich combustion, and the corresponding flame is called a rich flame. Combustion with a high air coefficient is called lean combustion, and the corresponding flame is called a lean flame. Both rich and lean combustion can suppress nitrogen oxide production, but they rely on different mechanisms. Furthermore, the total air coefficient for rich-lean combustion should be close to (slightly higher than) the air coefficient for fully premixed intake.

[0004] Based on the above-mentioned rich-lean combustion principle, people have proposed a rich-lean burner, which is a mixed burner that combines rich flame and lean flame. The air coefficient of the lean flame is higher, the gas is insufficient, and the flame is shorter; the air coefficient of the rich flame is lower, the air is insufficient, and the flame is elongated.

[0005] Rich-lean combustion technology is most widely used in combustion appliances such as gas water heaters. Publication No. CN205480981A discloses a rich-lean burner, including a fire grate, which is composed of an inner plate, an outer plate, and a center plate group, wherein the center plate group also includes a center side plate and a center inner plate. Each fire grate must be provided with a rich combustion inlet and a lean combustion inlet, respectively, and is a double-injection port burner. The auxiliary flame holes for rich combustion are located on both sides of the main flame hole for lean combustion, which belongs to the "rich outside and lean inside" combustion mode. The burner also belongs to the fully premixed gas supply mode, that is, air is no longer added during the gas circulation process. A single fire grate has many parts, a complex structure, and high assembly precision requirements. Summary of the Invention

[0006] The present invention aims to provide a novel rich-lean combustion fire grate, burner, and water heater. By placing rich combustion on either side of a lean combustion system, the rich flame generated by the rich combustion system pulls the lean flame generated by the lean combustion system together, preventing the lean combustion system from straying from the center. This improves overall combustion stability and flame rigidity. This not only leverages the rich-lean combustion system's effectiveness in reducing nitrogen oxides in combustion products, but also enhances the safety and efficiency of rich-lean combustion.

[0007] Another object of the present invention is to design the components of the fire grate to minimize the number of assembly parts of a single fire grate, which not only saves materials but also helps to reduce assembly processes and improve production efficiency.

[0008] The technical solution adopted by the present invention to achieve the above technical purpose is: a new type of rich and thin combustion fire grate, including a core shell, an inner shell,

[0009] The core shell includes an ejection channel, a flow averaging chamber, and a flow diversion chamber arranged from bottom to top. The flow averaging chamber is opened at the top and bottom, connected to the flow diversion chamber at the top and the ejection channel at the bottom. The side wall of the flow diversion chamber is provided with a plurality of rich combustion outlet structures and a plurality of lean combustion outlet structures arranged at intervals along the length direction.

[0010] The inner shell cover is outside the diverter chamber and includes an air intake chamber, a lean burn mixing chamber, a plurality of air guide structures and a rich burn flame hole structure arranged from bottom to top on the side wall of the inner shell. The plurality of air guide structures are in contact and conduction with the plurality of rich burn outlet structures in a one-to-one correspondence. The air intake chamber cover forms an air intake gap outside the diverter chamber and outside the side wall of the diverter chamber. The bottom of the air intake gap is provided with an air intake structure and the top is upwardly conducted with the lean burn mixing chamber. The plurality of lean burn outlet structures are upwardly conducted with the lean burn mixing chamber, and the combustion top surface of the lean burn mixing chamber is provided with a lean flame hole.

[0011] An upwardly open rich combustion gas outlet gap is formed between the inner shells of two adjacent fire rows arranged side by side, and a rich flame hole is formed at the top of the rich combustion gas outlet gap through the rich combustion flame hole structure, and the multiple gas guide structures are connected to the rich combustion gas outlet gap.

[0012] Furthermore, an air flow channel is formed between two adjacent fire banks arranged side by side. The air flow channel is connected to the air intake gap through the air intake structure, but is not connected to the rich burn outlet gap. This allows as much of the supplementary air in the air flow channel as possible to be directed into the air intake gap to supplement the lean burn mixing chamber, thereby forming a lean burn at the lean burn holes on the top surface of the burner.

[0013] Furthermore, frame-shaped ridges are formed on both side walls of the inner shell, extending from the inside out. Two adjacent fire bars, arranged side by side, are sealed together by these ridges, forming the rich burn outlet gap, which is open only at the top. These ridges are U-shaped and extend along the edges of the inner shell side walls. This design prevents air in the air flow path from flowing upward into the rich burn outlet gap, directing air toward the air intake structure. This ensures a low air coefficient for rich burn combustion while preventing air from interfering with the smooth supply of premixed gas to the rich burn outlet gap from the air guide structure.

[0014] Furthermore, the rich combustion flame hole structure is a rich flame groove formed on the side wall of the inner shell, and the rich flame groove extends up and down. The two opposite rich combustion flame hole structures are staggered with each other, that is, the concave part of the rich flame groove on one side is opposite to the convex part of the rich flame groove on the other side. Several rich flame grooves are continuously arranged along the length direction of the inner shell to form a rich flame groove unit. The two staggered rich flame groove units form a wavy rich flame hole, and multiple rich flame holes are arranged at intervals along the length direction of the inner shell.

[0015] Furthermore, a diversion structure is provided between adjacent rich flame groove units, through which premixed gas supplied from the rich combustion outlet gap flows to each rich flame hole. The diversion structure is a short rib punched from the inside out on the sidewall of the inner shell, extending vertically and separating adjacent rich flame holes.

[0016] Preferably, the light flame holes and the rich flame grooves that are close to each other correspond to each other in the width direction of the combustion top surface of the light combustion mixing chamber. Furthermore, the light flame holes and the rich flame grooves correspond one-to-one, and the rich flame in the rich flame groove is used to pull the light flame at the light flame hole.

[0017] Furthermore, the ejection channel includes a Venturi tube and a drainage pipe, the drainage pipe and the Venturi tube being connected in a U-shaped pattern. The equalizing chamber has a fan-shaped structure, with an upper straight edge extending in the longitudinal direction and a lower straight edge extending at an angle, and the drainage pipe extends obliquely along the lower straight edge. The premixed gas entering through the Venturi tube is evenly distributed to the diverter chamber through the interaction of the drainage pipe and the equalizing chamber. The aforementioned "even distribution" refers to the uniform distribution of the premixed gas along the length of the diverter chamber.

[0018] Furthermore, the diversion chamber has a closed top surface, and the rich burn gas outlet structure and the lean burn gas outlet structure respectively arranged on the two side walls of the diversion chamber are symmetrical to each other. The rich burn gas outlet structure on the same side wall is located above the lean burn gas outlet structure, and several rich burn gas outlet structures and several lean burn gas outlet structures are staggered in the upper and lower directions, thereby forming stable premixed gas outlets for achieving rich combustion and premixed gas outlets for achieving lean combustion, minimizing the mutual interference of the two gas outlet airflows and ensuring the stability of their respective airflows.

[0019] Furthermore, the rich burn gas outlet structure includes an external protrusion formed from the inside to the outside on the side wall of the diversion chamber, and a rich burn gas outlet hole formed by punching on the end face of the external protrusion; the lean burn gas outlet structure includes a convex hole directly punched from the inside to the outside on the side wall of the diversion chamber, and the orifice of the convex hole faces upward, and the convex hole serves as a lean burn gas outlet hole.

[0020] Furthermore, the plurality of gas-guiding structures include an inner protrusion formed from the outside inward on the sidewall of the inner shell, and rich-burn gas-guiding holes punched into the end faces of the inner protrusions. The inner protrusions and the end faces of the outer protrusions abut against each other to form a contact seal (around the periphery of the gas-guiding holes and the gas outlet holes). The rich-burn gas-guiding holes are in one-to-one communication with the rich-burn gas outlet holes. The rich-burn gas-guiding holes direct the premixed gas flowing out of the rich-burn gas outlet holes out of the inner shell, separating it from the lean-burn mixing chamber.

[0021] Furthermore, an inner convex strip is formed on the side wall of the inner shell from the outside to the inside, and the inner convex strip extends along the length direction (preferably extends throughout the entire length). The plurality of air guide structures are formed on the inner convex strip, and the long gap formed by the inner convex strip and the side wall of the diversion chamber is divided into a plurality of slow flow holes by a plurality of mutually contacting rich combustion outlet structures and air guide structures, so that the air intake gap and the lean combustion mixing chamber are connected up and down through the plurality of slow flow holes. The premixed gas flowing upward from the lean combustion outlet structure and the supplementary air flowing upward from the air intake gap enter the lean combustion mixing chamber respectively through the plurality of slow flow holes. The plurality of slow flow holes help to evenly premix the premixed gas and supplementary air used for lean combustion.

[0022] Furthermore, the bottom of the side wall of the air intake chamber converges inward ("converging inward" refers to enveloping the core shell) to form an air intake slope. The bottom edge of the air intake slope forms a sealed contact with the outer wall of the core shell, thereby achieving a sealed wrapping of the bottom of the diversion chamber by the air intake chamber. A plurality of air intake slits are provided on the air intake slope, which serves as the air intake structure. Considering the difficulty of assembling the "bottom sealed wrapping" on the production line, the air intake structure of the present application can also adopt another embodiment: the bottom of the side wall of the air intake chamber is configured as a concave-convex structure, and the air intake hole is formed by the concave-convex structure and the outer wall of the core shell.

[0023] Furthermore, the top surface of the lean combustion mixing chamber is a plane or an inverted V-shaped top surface, and the lean flame holes are arranged on the inclined surface of the inverted V-shaped top surface, so that the lean flame has a counteracting tendency against the rich flame on the side.

[0024] Another object of the present invention is to provide a rich-lean burner, comprising a plurality of fire bars, the plurality of fire bars being arranged side by side, the fire bars being of the above-described structure; a windshield having a plurality of air holes is further provided below the plurality of fire bars; a partition is provided on the outside of the fire bar at the endmost end, the rich combustion gas outlet gap being formed between the partition and the outer wall of the inner shell of the fire bar, and a rich flame hole being formed between the partition and the rich combustion flame hole structure. The fire bar at the endmost end refers to the fire bar at the head and tail ends of the plurality of fire bars arranged side by side, and the function of the partition is to form a rich combustion gas outlet gap on the outside of the fire bar at the endmost end, and to generate a rich flame at the top of the rich combustion gas outlet gap.

[0025] The present invention also provides the following application of the above-mentioned thick-thin burner on a water heater:

[0026] A household gas instantaneous water heater comprises the above-mentioned thick-lean burner, a water tank and an air outlet unit.

[0027] A gas heating water boiler comprises the above-mentioned thick-lean burner, a water tank and an air outlet unit.

[0028] A steam heat source machine comprises the above-mentioned thick-lean burner, a water tank and an air outlet unit.

[0029] Compared with the prior art, the advantages of the present invention include at least:

[0030] (1) In order to reduce the amount of nitrogen oxides produced in the combustion products, the burner of the present application adopts the principle of rich-lean combustion and adopts a single injection hole in structure. Gas entrained with air (premixed gas) is injected into the core shell through the single injection hole. The premixed gas is split and one path is drawn out to achieve rich combustion with a lower air coefficient, and the other path is mixed with supplementary air to achieve lean combustion with a higher air coefficient.

[0031] (2) The top surface of the fire grate is light combustion, and the space between the fire grate is rich combustion, thereby realizing the interval setting of rich and light flames. The rich flame consumes the excess air in the light flame, thereby holding the light flame and preventing flameout. This makes the overall combustion more stable and improves the flame rigidity.

[0032] (3) Using a single ejection hole to intake air, the Venturi tube, the drainage pipe and the flow equalization chamber are used to reduce the dead angle of gas flow and improve the uniformity of the initial gas distribution in the length direction of the fire row.

[0033] (4) The rich burn outlet structure is located above the lean burn outlet structure, and a lean burn mixing chamber is provided in the upper portion of the inner shell, thereby extending the flow of the premixed gas into the lean burn mixing chamber. Within the air intake gap, the premixed gas and air can be premixed during the flow process. The lean burn outlet structure and the rich burn outlet structure are staggered vertically, making the premixed gas flow for rich and lean combustion relatively stable and uniform.

[0034] (5) An air intake gap is formed between the core shell and the inner shell, and an air flow channel is formed between adjacent fire bars. The air intake gap and the air flow channel are connected through the air intake structure, thereby achieving mixing of supplementary air and premixed gas in the air intake gap.

[0035] (6) The air intake structure adopts air intake slits on the intake slope, thereby achieving uniform air intake. Of course, this is only a preferred embodiment of the present invention and should not be understood as limiting the air intake structure of the present invention.

[0036] (7) The rich burn outlet gap is designed as a semi-enclosed structure with an open top, so that it is isolated from the air flow channel or the air intake gap, which helps to completely prevent the supplementary air from interfering with the premixed gas in the rich burn outlet gap, ensuring that the rich burn maintains a low air coefficient and stable outlet gas.

[0037] (8) The lean burn outlet structure is located in the air intake gap, and supplementary air continuously flows into the air intake gap. The lean burn outlet structure preferably has an upward outlet so that the supplementary air and the premixed gas are mixed in the rising process as two nearly parallel air flows, thereby avoiding the supplementary air from forming an air seal on the lean burn outlet structure and hindering the smooth outlet of the premixed gas.

[0038] (9) The concentrated fire holes of the present application are wavy in shape, and the concentrated flames coming out of each concentrated fire hole are also wavy in shape. Part of the flame of each concentrated flame approaches the light flame on the left, and the other part of the flame approaches the light flame on the right, so that the concentrated flames between adjacent fire rows can interfere with the light flames on the fire rows on both sides at the same time.

[0039] (10) Based on point (9) above, the fire bars of this application do not achieve rich and thin combustion alone. The fire bars must cooperate with each other to achieve rich and thin combustion with staggered distribution of rich and thin flames. This application consists of two parts, the core shell and the inner shell. The structure for achieving rich and thin combustion is mainly based on the inner shell. The top of the inner shell of each fire bar is used to achieve thin combustion, and the inner shells between adjacent fire bars are used to achieve rich combustion. The structural design is compact and ingenious, the number of parts is small, the manufacturing cost is low, and it is conducive to promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a front view of a fire bar in an embodiment of the present invention;

[0041] Figure 2 A top view of a fire bar according to an embodiment of the present invention;

[0042] Figure 3 This is a left side view of the fire bar in an embodiment of the present invention;

[0043] Figure 4 A three-dimensional diagram of a fire grate in an embodiment of the present invention;

[0044] Figure 5 This is an exploded view of the fire grate in an embodiment of the present invention;

[0045] Figure 6 is a perspective view of a burner in an embodiment of the present invention;

[0046] Figure 7 A three-dimensional diagram of a burner from another perspective in an embodiment of the present invention;

[0047] Figure 8 A front view of a burner according to an embodiment of the present invention;

[0048] Figure 9 A top view of a burner in an embodiment of the present invention;

[0049] Figure 10 A bottom view of a burner in an embodiment of the present invention;

[0050] Figure 11 for Figure 9 Middle CC section view;

[0051] Figure 12 It is a cross-sectional view of the two fire bars at the end;

[0052] In the figure, the core shell 1, the inner shell 2, the air flow channel 3, the wind shield 4, the partition 5, the shell 6, the exhaust hole 62, the venturi tube 11, the guide tube 12, the flow equalizing chamber 13, the diversion chamber 14, the closed top surface 15, the outer protrusion 16, the rich burn air outlet hole 17, the lean burn air outlet hole 18, the air intake chamber 21, the lean burn mixing chamber 22, the air intake gap 23, the air intake slope 24, the air intake slit 25, the lean fire hole 26, the inner protrusion 27, the rich burn air guide hole 28, the inner convex strip 29, the rich flame groove 31, the rich flame groove unit 32, the rich burn air outlet gap 34, the frame convex strip 35, the short convex strip 36, the rich fire hole 37, and the air hole 41. DETAILED DESCRIPTION

[0053] The present invention will be further described in detail below with reference to the accompanying drawings. The embodiments described are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention. The textual descriptions in this embodiment correspond to the accompanying drawings, and the descriptions of the directions are also based on the accompanying drawings and should not be construed as limiting the scope of protection of the present invention. Example 1

[0054] This embodiment relates to a novel rich-lean combustion fire grate, comprising a core shell 1 and an inner shell 2, wherein the inner shell 2 is sleeved on top of the core shell 1. The core shell 1 and the inner shell 2 are respectively formed by two symmetrical side plates connected together, and the connection method can be a side plate wrapped around the other side plate, or a side plate butt welding.

[0055] like Figure 1-5 As shown, the core shell 1 includes an ejection channel, a flow balancing chamber 13, and a diversion chamber 14 arranged from bottom to top. Among the three, the flow balancing chamber 13 is the narrowest, with upper and lower openings, connected to the diversion chamber 14 on the upper side, and the ejection channel on the lower side. The ejection channel includes a venturi tube 11 and a drainage pipe 12, and the drainage pipe 12 is connected to the venturi tube 11 in a U-shaped manner. The flow balancing chamber 13 has an arc-shaped deflection area and is approximately fan-shaped. It has an upper straight edge extending in the longitudinal direction and a lower straight edge extending obliquely. The drainage pipe 12 extends obliquely along the lower straight edge, and the diameter of the drainage pipe 12 gradually narrows along the flow direction of the gas. From a structural point of view, it is possible to achieve uniform flow of gas on the straight edge of the flow balancing chamber 13. In order to give full play to the role of the venturi tube 11, the drainage pipe 12, and the flow balancing chamber 13 in evenly distributing gas, the two side plates of the core shell 1 are fitted together at the bottom and left and right sides of the three to eliminate airflow dead corners.

[0056] The diversion chamber 14 is used to realize the gas diversion of rich and lean combustion, and has a closed top surface 15. A plurality of rich combustion outlet structures and a plurality of lean combustion outlet structures are respectively arranged on the two side walls of the diversion chamber 14 at intervals along the length direction. The rich combustion outlet structures and lean combustion outlet structures on the two side walls are symmetrical to each other. The rich combustion outlet structure on the same side wall is located above the lean combustion outlet structure. Figure 1 As shown, a plurality of rich burn gas outlet structures are arranged at the top edge of the side wall, and the rich burn gas outlet structures and the lean burn gas outlet structures are staggered in the vertical direction at a ratio of 1:2.

[0057] Specifically, the rich-burn gas outlet structure includes an outer protrusion 16 formed from the inside out on the sidewall of the diverter chamber 14, and a rich-burn gas outlet hole 17 punched into the end face of the outer protrusion 16. The lean-burn gas outlet structure includes a convex hole directly punched from the inside out on the sidewall of the diverter chamber 14, with the hole opening facing upward. This convex hole serves as the lean-burn gas outlet hole 18.

[0058] like Figure 4-5As shown, the inner shell 2 includes an air intake chamber 21 and a lean-burn mixing chamber 22 arranged from bottom to top. The air intake chamber 21 covers the outside of the diverter chamber 14, and the lean-burn mixing chamber 22 is located above the diverter chamber 14. An air intake gap 23 is formed outside the side walls of the air intake chamber 21 and the diverter chamber 14. The air intake gap 23 is connected to the lean-burn mixing chamber 22 above. The top surface of the lean-burn mixing chamber 22 is provided with a lean-burn hole 26. The bottom of the side wall of the air intake chamber 21 is folded inward to form an intake slope 24. The bottom edge of the intake slope 24 is in contact with the outer wall of the core shell 1, thereby achieving a nearly sealed wrapping of the bottom of the diverter chamber 14 by the air intake chamber 21. A plurality of air intake slits 25 are further provided on the intake slope 24. The air intake slits 25 serve as the air intake structure of the air intake gap 23.

[0059] The air intake gap 23 and the lean burn outlet hole 18 are respectively connected to the lean burn mixing chamber 22. The premixed gas supplied from the lean burn outlet hole 18 enters the air intake gap 23, is premixed with the air rising in the air intake gap 23, and then enters the lean burn mixing chamber 22 for further mixing, and finally burns at the lean flame hole 26 to form a lean flame.

[0060] The inner shell 2 not only realizes the diversion of the premixed gas: one path is used for the gas supply of rich combustion, and the other path is used for the gas supply of lean combustion, but also realizes the combustion of rich combustion.

[0061] To divert the premixed gas, several gas-guiding structures are provided on the sidewall of the inner shell 2. These structures are in one-to-one contact and communication with the rich-burn gas outlet structures. Specifically, these structures include an inner protrusion 27 formed from the outside inward on the sidewall of the inner shell 2, and rich-burn gas-guiding holes 28 punched into the end surface of the inner protrusion 27. The inner protrusion 27 abuts the end surface of the outer protrusion 16 of the rich-burn gas outlet structure, forming a contact seal. The rich-burn gas-guiding holes 28 are in one-to-one communication with the rich-burn gas outlet holes 17, thereby directing the premixed gas for rich combustion out of the inner shell 2.

[0062] In this embodiment, an inner convex strip 29 is formed on the side wall of the inner shell 2 from the outside to the inside, and the inner convex strip 29 extends along the length direction and extends throughout the length. The above-mentioned air guide structure is formed on the inner convex strip 29, and the inner protrusion 27 is flush with the end face of the inner convex strip 29. Structurally, the inner convex strip 29 is abutted against the end face of the outer protrusion 16 of the rich-burn gas outlet structure. In this way, the long gap formed by the inner convex strip 29 and the side wall of the diversion chamber 14 is separated into a number of slow-flow channels by the multiple outer protrusions 16, so that the air intake gap 23 and the lean-burn mixing chamber 22 are connected up and down through the multiple slow-flow channels.

[0063] Frame-shaped ridges 35 are formed on both sidewalls of the inner shell 2, extending from the inside outward. These ridges 35 extend along the edges of the sidewalls, forming a U-shape with an open top. Furthermore, rich-burn flame hole structures are provided on both sidewalls of the inner shell 2, located at the top edges of the sidewalls. Two adjacent fire rows, arranged side by side, are in sealed contact with each other through the frame-shaped ridges 35, forming an open-top rich-burn gas outlet gap 34. The rich-burn flame hole structures, spaced relative to each other, form rich-burn holes 37 at the top of the rich-burn gas outlet gap 34, and the rich-burn gas guide holes 28 are in communication with the rich-burn gas outlet gap 34.

[0064] An air channel 3 is formed between two adjacent fire banks, primarily between the core shells 1. Air channel 3 is located below the rich burn outlet gap 34, and there is little communication between the two. That is, air in air channel 3 hardly flows upward into the rich burn outlet gap 34. Air channel 3 communicates with air intake gap 23 via air intake slits 25. Therefore, it can be considered that air channel 3 only supplies air to air intake gap 23.

[0065] like Figure 4 、 5 As shown, the rich flame hole structure of this embodiment is a rich flame groove 31 formed on the side wall of the inner shell 2. The rich flame groove 31 extends up and down and protrudes from the side wall of the inner shell. The two opposite rich flame hole structures are staggered with each other, that is, the concave portion of the rich flame groove (31) on one side is opposite to the convex portion of the rich flame groove 31 on the other side. A plurality of consecutive rich flame grooves 31 form a rich flame groove unit 32. The two staggered rich flame groove units 32 form a wavy rich flame hole 37. The multiple rich flame holes 37 are arranged at intervals along the length direction.

[0066] Two rows of light flame holes 26 are provided on the combustion top surface of the inner shell 2 along the length direction. The light flame holes 26 correspond to and approach the rich flame grooves 31 in the width direction. Since the rich flame grooves 31 on both sides of the rich fire hole 37 are staggered with each other, the two rows of light flame holes 26 on the same combustion top surface are also staggered with each other.

[0067] A plurality of short ridges 36 are stamped outward from the inside of the inner shell 2 to form a sidewall thereof. Each short ridge 36 extends vertically and is located between adjacent rich flame groove units 32. Furthermore, the short ridges 36 on either side of the rich flame holes 37 are in one-to-one contact with each other, thereby separating adjacent rich flame holes 37. The premixed gas supplied from the rich combustion outlet gap 34 is diverted by the plurality of short ridges 36 in contact with each other and then supplied to each rich flame hole 37.

[0068] The thick and thin combustion process of the above fire grate is as follows:

[0069] The gas entrained with air is evenly distributed to the diversion chamber 14 through the venturi tube 11, the draft tube 12, and the equalizing chamber 13. The premixed gas in the diversion chamber 14 enters the air intake gap 23 from the lean burn outlet 18 below, where it is premixed with the supplementary air entering the air intake gap 23 from the air intake slit 25. It then moves upward into the lean burn mixing chamber 22 for further mixing, and finally burns at the lean flame hole to form a lean flame. Another portion of the premixed gas in the diversion chamber 14 enters the lean burn outlet gap 34 from the lean burn outlet 17 and the lean burn air guide hole 28 above, and finally burns at the wavy lean burn hole 37 to form a lean flame. The lean flame is located between adjacent fire bars, while the lean flame is located on the top of the fire bar, forming a lean and lean combustion pattern.

[0070] The rich flame of each rich flame hole 37 is wavy and can interfere with the light flames on both sides. The oxygen-poor rich flame consumes the excess oxygen in the light flame to avoid flameout of the light flame, thereby improving flame rigidity and stabilizing combustion. Example 2

[0071] This embodiment relates to a burner comprising multiple fire bars, which are arranged side by side and fixedly mounted within a housing 6. The housing 6 is positioned around the periphery of all the fire bars. Exhaust holes 62 are provided in the housing 6 and are arranged along the edges of the housing to facilitate the upward and downward circulation of air, thereby preventing the formation of cyclonic vortices between the housing 6 and all the fire bars, particularly in the corners. The fire bars are those described in Example 1. A partition 5 is provided on the outer side of the fire bar at the end. A rich combustion air outlet gap 34 is formed between the partition 5 and the outer wall of the inner shell of the endmost fire bar. Rich combustion holes 37 are also formed between the partition 5 and the rich combustion flame hole structure.

[0072] A windshield 4 is provided below the multiple fire bars, and is provided with air holes 51. The edges of the windshield 4 are also provided with edge holes for air diversion and uniform air intake. This is used to form air flows on both sides of each fire bar, which not only cools the fire bar but also pushes the dense flames from the outside inward. Example 3

[0073] This embodiment relates to a water heater, such as a household gas instantaneous water heater, a gas heating water boiler, or a steam heat source, comprising the rich-lean burner described in Example 2, a water tank, and an air outlet unit. The air outlet unit can be either an upward draft or downward draft fan. The water tank is located above the rich-lean burner.

[0074] In addition to the above embodiments, the present invention also includes other implementation methods. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the scope of protection of the claims of the present invention.

Claims

1. A new type of dense and thin combustion fire grate, characterized by: It includes a heart shell (1) and an inner shell (2). The core shell (1) includes an ejection channel, a flow averaging chamber (13), and a flow diversion chamber (14) arranged from bottom to top. The flow averaging chamber (13) is open at the top and bottom, connected to the flow diversion chamber (14) at the top and the ejection channel at the bottom. The side wall of the flow diversion chamber (14) is provided with a plurality of rich combustion outlet structures and a plurality of lean combustion outlet structures arranged at intervals along the length direction. The inner shell (2) is covered outside the diversion chamber (14), and includes an air intake chamber (21), a light combustion mixing chamber (22), and a plurality of air guide structures and rich combustion flame hole structures arranged from bottom to top on the side wall of the inner shell. The plurality of air guide structures are in contact and conduction with the plurality of rich combustion outlet structures in a one-to-one correspondence. The air intake chamber (21) is covered outside the diversion chamber (14) and forms an air intake gap (23) outside the side wall of the diversion chamber (14). The bottom of the air intake gap (23) is provided with an air intake structure, and the top is upwardly conducted with the light combustion mixing chamber (22). The plurality of light combustion outlet structures are upwardly conducted with the light combustion mixing chamber (22), and the combustion top surface of the light combustion mixing chamber (22) is provided with a light flame hole (26); An upwardly open rich combustion gas outlet gap (34) is formed between the inner shells (2) of two adjacent fire rows arranged side by side, and a rich flame hole (37) is formed at the top of the rich combustion gas outlet gap (34) through the rich combustion flame hole structure, and the plurality of gas guide structures are in conduction with the rich combustion gas outlet gap (34); An air flow channel (3) is formed between two adjacent fire rows arranged side by side, and the air flow channel (3) is connected to the air intake gap (23) through the air intake structure; the air flow channel (3) is not connected to the rich combustion outlet gap (34); the bottom of the side wall of the air intake chamber (21) is inwardly contracted to form an air intake slope (24), and the bottom edge of the air intake slope (24) is in sealed contact with the outer wall of the core shell (1), thereby achieving the air intake chamber sealing the bottom of the diversion chamber (14), and a plurality of air intake slits (25) are provided on the air intake slope (24), which serves as the air intake structure; Frame-shaped convex strips (35) are formed on both side walls of the inner shell (2) from the inside out, and two adjacent fire bars arranged side by side are in sealed contact through the frame-shaped convex strips (35) to form a top-open rich combustion gas outlet gap (34); The rich combustion flame hole structure is a rich flame groove (31) formed on the side wall of the inner shell (2), the rich flame groove (31) extends up and down, and the two opposite rich combustion flame hole structures are staggered with each other, that is, the concave portion of the rich flame groove (31) on one side is opposite to the convex portion of the rich flame groove (31) on the other side; a plurality of the rich flame grooves (31) are continuously arranged along the length direction of the inner shell (2) to form a rich flame groove unit (32), and the two staggered rich flame groove units (32) form a wavy rich flame hole (37), and a plurality of the rich flame holes (37) are arranged at intervals along the length direction of the inner shell (2).

2. The fire bar according to claim 1, characterized in that: The light-fire holes (26) and the rich-fire grooves (31) that are adjacent to each other correspond to each other along the width direction of the combustion top surface of the light-fire mixing chamber (22).

3. The fire bar according to claim 1, characterized in that: A diversion structure is provided between adjacent rich flame groove units (32), and the premixed gas supplied from the rich combustion gas outlet gap (34) flows to each rich flame hole (37) through the diversion structure; the diversion structure is a short convex strip (36) punched from the inside to the outside on the side wall of the inner shell, and the short convex strip (36) extends up and down, and adjacent rich flame holes (37) are separated by the short convex strip (36).

4. The fire bar according to claim 1, characterized in that: The ejection channel comprises a Venturi tube (11) and a drainage tube (12), wherein the drainage tube (12) is connected to the Venturi tube (11) in a U-shape; the flow equalization chamber (13) is a fan-shaped structure having an upper straight edge extending in the longitudinal direction and a lower straight edge extending obliquely, and the drainage tube (12) extends obliquely along the lower straight edge.

5. The fire bar according to claim 1, characterized in that: The diversion chamber (14) has a closed top surface, and the rich burn gas outlet structure and the lean burn gas outlet structure respectively arranged on the two side walls of the diversion chamber (14) are symmetrical to each other, the rich burn gas outlet structure on the same side wall is located above the lean burn gas outlet structure, and a plurality of rich burn gas outlet structures and a plurality of lean burn gas outlet structures are staggered in the vertical direction.

6. The fire bar according to claim 1, characterized in that: The rich burn gas outlet structure includes an outer protrusion (16) formed from the inside out on the side wall of the diversion chamber (14), and a rich burn gas outlet hole (17) formed by punching the end face of the outer protrusion (16); the lean burn gas outlet structure includes a convex hole directly punched from the inside out on the side wall of the diversion chamber, with the orifice of the convex hole facing upward, and the convex hole serves as a lean burn gas outlet hole (18).

7. The fire bar according to claim 6, characterized in that: The plurality of gas guide structures include an inner protrusion (27) formed from the outside to the inside on the side wall of the inner shell (2), and a rich combustion gas guide hole (28) punched on the end face of the inner protrusion (27), the inner protrusion (27) and the end face of the outer protrusion (16) abut against each other to form a contact seal, and the rich combustion gas guide hole (28) and the rich combustion gas outlet hole (17) are connected one by one.

8. The fire bar according to claim 1, characterized in that: An inner convex strip (29) is formed on the side wall of the inner shell (2) from the outside to the inside, and the inner convex strip (29) extends along the length direction. The plurality of air guide structures are formed on the inner convex strip (29). The long gap formed by the inner convex strip (29) and the side wall of the diversion chamber (14) is divided into a plurality of slow flow holes by a plurality of mutually contacting rich combustion outlet structures and air guide structures, so that the air intake gap (23) and the lean combustion mixing chamber (22) are connected to each other in an upper and lower direction through the plurality of slow flow holes.

9. The fire bar according to claim 1, characterized in that: The combustion top surface of the light-burn mixing chamber (22) is a plane or an inverted V-shaped top surface, and the light-burn hole (26) is arranged on the inclined surface of the inverted V-shaped top surface.

10. A rich-lean burner, characterized in that: The invention comprises a plurality of fire bars, wherein the plurality of fire bars are combined side by side, and the fire bars are the fire bars according to any one of claims 1 to 9; a windshield (4) is further provided below the plurality of fire bars, and the windshield (4) has a plurality of air holes (41); a partition (5) is provided on the outer side of the fire bar at the end, and the rich combustion gas outlet gap (34) is formed between the partition (5) and the outer side wall of the inner shell of the fire bar, and a rich combustion hole is formed between the partition (5) and the rich combustion flame hole structure.

11. A water heater, characterized in that: It comprises the rich-lean burner, water tank and air outlet unit as described in claim 10.

12. The water heater according to claim 11, characterized in that: The water heater is selected from one of a household gas instantaneous water heater, a gas heating water heater and a steam heat source machine.

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