Fire grate, burner and water heater for achieving dense and thin combustion

Abstract

The present invention relates to a fire grate, a burner and a water heater for realizing rich and thin combustion, comprising a core shell, an inner shell and an outer shell. The core shell comprises an ejection channel, a flow equalization chamber and a flow diversion chamber. A rich combustion outlet structure and a thin combustion outlet structure are arranged on the side wall of the flow diversion chamber. The inner shell comprises a thin combustion mixing chamber and an air intake chamber. An air guide structure is arranged on the side wall of the inner shell, which is in contact and conduction with the rich combustion outlet structure in a one-to-one correspondence. An air intake gap is formed outside the air intake chamber and the side wall of the flow diversion chamber. The air intake gap is in conduction with the thin combustion outlet structure and is in conduction with the thin combustion mixing chamber upward. A thin combustion hole is arranged on the top surface of the thin combustion mixing chamber. The outer shell comprises a rich combustion outlet chamber and an air guide chamber. An air guide gap is formed between the air guide chamber and the side wall of the air intake chamber. A rich combustion outlet gap is formed between the rich combustion outlet chamber and the side wall of the thin combustion mixing chamber. The air guide structure is in conduction with the rich combustion outlet gap, and a rich combustion hole is formed on the top of the rich combustion outlet gap.

Description

Technical Field

[0001] The invention relates to a water heater, a thick-thin burner and a fire grate thereof, in particular to a water heater, a thick-thin burner and a fire grate thereof which can significantly reduce nitrogen oxide emission and stabilize flame. 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 civil gas appliances. Manufacturers attach great importance to the production of nitrogen oxides in the design and production of gas appliances.

[0003] As an effective combustion technology that can significantly reduce nitrogen oxide emissions, the rich-lean combustion method has received attention from major gas appliance manufacturers.

[0004] Studies have shown that the size of the air coefficient can significantly affect the amount of nitrogen oxides produced in the combustion products. When the air coefficient is small or high, the nitrogen oxides in the combustion products are low. Specifically, when the air coefficient is low, such as less than 0.6, due to insufficient air supply, the combustion temperature is low, and the oxygen content in the combustion zone is also low, which inhibits the production of nitrogen oxides; when the air coefficient is high, significantly exceeding 1.0, such as greater than 1.4, the air is oversupplied. Although the excess air increases the oxygen concentration in the combustion zone, the excess air also takes away a large amount of heat in the combustion zone, causing the combustion temperature to decrease. The decrease in combustion temperature also helps to inhibit the production of nitrogen oxides. We call the combustion with a smaller air coefficient rich combustion, and the corresponding flame is called rich flame; the combustion with a larger air coefficient is called lean combustion, and the corresponding flame is called lean flame. Both rich combustion and nitrogen combustion can inhibit the production of nitrogen oxides, but the inhibition principles are different. In addition, the total air coefficient of rich and lean combustion should be close to (slightly higher than) the air coefficient of the full premixed intake mode.

[0005] 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 light flame. The air coefficient of the light 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.

[0006] Rich-lean combustion technology is most widely used in fuel appliances such as gas water heaters.

[0007] The patent document with announcement number CN205480981U owned by applicant: Taiwan Sakura Co., Ltd. (hereinafter referred to as Sakura) relates to a rich-lean burner, "including a plurality of fire rows, each fire row including two inner plates, two outer plates and a central plate group, the two inner plates are connected to each other, a containing space, a rich combustion inlet, a lean combustion inlet and a lean flame flow channel are formed between the two inner plates, the lean flame flow channel is connected to the lean combustion inlet; the two outer plates are connected to each other, the two outer plates are arranged on the outer sides of the two inner plates, and the two outer plates are connected to the two inner plates, two rich flame flow channels are formed between the two outer plates and the two inner plates, the rich flame flow channels are connected to the rich combustion inlet, the two inner plates are respectively provided with a plurality of through holes corresponding to the rich combustion inlet, so that the rich combustion inlet is connected to the rich flame flow channel through these through holes, the upper end of the rich flame flow channel is respectively formed with a secondary flame hole, the rich flame flow channel The thick flame flow passage is connected to the thick combustion inlet and the two auxiliary flame holes, and a narrow and long protrusion and a triangular protrusion are respectively provided in the thick flame flow passage; the center plate group is arranged in the accommodating space, and the center plate group includes two center side plates and at least one center inner plate, and the at least one center inner plate is arranged between the two center side plates, and the two sides of the two center side plates and the at least one center inner plate and the two sides are provided with a plurality of interconnected connecting parts at intervals, and a plurality of main flame holes penetrating upward and downward are formed between the two center side plates and the at least one center inner plate, and the light flame flow passage is connected to the light combustion inlet and these main flame holes, and the lower ends of the two center side plates each extend outward to form an outer protrusion, and the outer protrusion abuts against the adjacent inner plates of the two inner plates, so that a spacing space is formed between the two sides of the center plate group and the two inner plates. "It can be seen that each fire row of Sakura's thick and light burner must be provided with a thick combustion inlet and a light combustion inlet respectively, which belongs to a double-injection port burner. The auxiliary flame holes for rich combustion are located on both sides of the main flame holes for lean combustion, which is a combustion mode of "rich outside and lean inside". The burner also belongs to the full premixed gas supply mode, that is, no air is added during the gas circulation process. Summary of the invention

[0008] The purpose of the present invention is to provide a rich-lean burner and its monomer, which can improve the stability of combustion and the flame rigidity of the overall combustion by arranging the rich combustion on both sides of the lean combustion, so that the rich flame generated by the rich combustion pulls the lean flame generated by the lean combustion, and avoids the de-ignition phenomenon of the lean combustion in the middle, thereby improving the effect of the rich-lean combustion method in reducing the amount of nitrogen oxides generated in the combustion products, and improving the safety and combustion efficiency of the rich-lean combustion.

[0009] The technical solution adopted by the present invention to achieve the above technical purpose is: a fire grate of a thick-thin burner, comprising a core shell, an inner shell, and an outer shell.

[0010] The core shell includes an ejection channel, a flow equalization chamber, and a flow distribution chamber arranged from bottom to top. The flow equalization chamber is opened at the top and bottom, connected to the flow distribution chamber at the top and the ejection channel at the bottom. The side wall of the flow distribution chamber is provided with a plurality of rich combustion outlet structures and a plurality of light combustion outlet structures arranged at intervals along the length direction.

[0011] The inner shell cover is outside the diverter chamber, and includes an air intake chamber, a lean combustion mixing chamber, and a plurality of air guide structures arranged from bottom to top on the inner shell side wall, and 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 diverter chamber and outside the side wall of the diverter chamber, the air intake gap is in conduction with the plurality of lean combustion outlet structures, an air intake structure is provided at the bottom of the air intake gap, the air intake gap is further in conduction with the lean combustion mixing chamber upwards, and a lean combustion hole is provided on the top surface of the lean combustion mixing chamber;

[0012] The outer shell cover is on the outside of the inner shell, and includes an air induction chamber and a rich combustion air outlet chamber arranged from bottom to top, a downwardly open air induction gap is formed between the air induction chamber and the side wall of the air inlet chamber, and the air inlet structure is located within the air induction gap; an upwardly open rich combustion air outlet gap is formed between the rich combustion air outlet chamber and the side wall of the lean combustion mixing chamber, the plurality of air guide structures are in communication with the rich combustion air outlet gap, and a rich fire hole is formed at the top of the rich combustion air outlet gap.

[0013] Furthermore, the air guide gap is not connected to the rich combustion outlet gap, and the air guide gap is connected to the air intake gap through the air intake structure, so that the supplementary air collected by the air guide gap is introduced into the air guide gap as much as possible for lean combustion.

[0014] As an embodiment of the present application, a long convex strip is formed on the side wall of the outer shell from the outside to the inside, and the long convex strip extends along the length direction. The long convex strip is in sealing contact with the outer wall of the inner shell, thereby separating the air guide gap and the rich combustion outlet gap from top to bottom so that they are not conductive. This arrangement is to prevent the air in the air guide gap from entering the rich combustion outlet gap upward, so that the air tends to enter the air intake gap through the air intake structure. The inventor of the present application preferably blocks the air guide gap and the rich combustion outlet gap, and completely prevents the mixing of air into the rich combustion outlet gap, so as to achieve a low air coefficient of rich combustion and prevent air from interfering with the smooth outlet of the air guide structure.

[0015] Furthermore, the plurality of light combustion gas outlet structures have upward gas outlets. The light combustion gas outlet structure is located in the air intake gap, and supplementary air continuously flows into the air intake gap. The upward gas outlet is to directly guide the gas coming out of the light combustion gas outlet structure upward, thereby forming two gas flows in the same direction and nearly parallel to each other with the supplementary air, so as to prevent the supplementary air flow from forming an air seal on the light combustion gas outlet structure and hindering the light combustion gas outlet structure from exhausting gas.

[0016] Furthermore, the ejection channel includes a venturi tube and a drainage tube, the drainage tube is connected to the venturi tube in a U-shape; the flow equalization chamber is a fan-shaped structure, having an upper straight edge extending in the length direction and a lower straight edge extending obliquely, and the drainage tube extends obliquely along the lower straight edge. The initial gas entering through the venturi tube is evenly distributed to the diversion chamber through the cooperation of the drainage tube and the flow equalization chamber, and the aforementioned "even distribution" refers to the even distribution of the initial gas along the length direction of the diversion chamber.

[0017] Furthermore, the diversion chamber has a closed top surface, and the rich combustion outlet structure and the lean combustion outlet structure respectively arranged on the two side walls of the diversion chamber are symmetrical to each other, the rich combustion outlet structure on the same side wall is located above the lean combustion outlet structure, and a plurality of rich combustion outlet structures and a plurality of lean combustion outlet structures are staggered in the up and down directions, thereby forming a stable initial gas outlet for achieving rich combustion and an initial gas outlet for achieving lean combustion, minimizing the mutual interference of the two outlet airflows to ensure airflow stability.

[0018] 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.

[0019] Furthermore, the plurality of gas guide structures include an inner protrusion formed from outside to inside on the side wall of the inner shell, and a rich combustion gas guide hole formed by punching on the end surface of the inner protrusion, the inner protrusion and the end surface of the outer protrusion abut against each other to form a contact seal (at the periphery of the gas guide hole and the gas outlet hole), and the rich combustion gas guide hole and the rich combustion gas outlet hole are connected one by one. The initial fuel gas flowing out of the rich combustion gas outlet hole is guided to the outside of the inner shell through the rich combustion gas guide hole to be separated from the lean combustion mixing chamber.

[0020] Furthermore, an inner convex strip is formed on the side wall of the inner shell from outside to inside, and the inner convex strip extends along the length direction (preferably extends throughout the length), and 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 initial combustion 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 through the plurality of slow flow holes respectively. The plurality of slow flow holes help to pre-mix the initial combustion gas and the supplementary air evenly.

[0021] Furthermore, the bottom of the side wall of the air intake chamber is gathered inward ("gathered inward" means wrapping the core shell) to form an air intake slope, and the bottom edge of the air intake slope is in sealed contact with the outer wall of the core shell, thereby achieving the air intake chamber's sealed wrapping of the bottom of the diversion chamber, and a plurality of air intake slits are arranged 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 arranged 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.

[0022] Furthermore, the bottom of the side wall of the air drainage chamber is formed into a concave-convex structure along the length direction. In the fire bar of the present application, the outer shells of adjacent fire bars are close to contacting each other (generally not in sealed contact), and preferably, the side walls of the air drainage chamber of the outer shell are close to contacting each other (generally not in sealed contact), thereby preventing air from flowing out from the gaps between adjacent fire bars more easily, making the air more inclined to enter the air drainage gap formed by the outer shell and the inner shell, and then enter the air intake gap, and mix with the gas coming out of the light combustion outlet structure.

[0023] Furthermore, a plurality of protrusions extending from outside to inside are arranged at intervals along the length direction on the top of the side wall of the rich combustion outlet chamber, and the protrusions press inward against the side wall of the lean combustion mixing chamber, thereby dividing the top of the rich combustion outlet gap into a plurality of rich fire holes arranged at intervals.

[0024] Furthermore, the top surface of the light combustion mixing chamber is a plane or an inverted V-shaped top surface, and the light flame holes are arranged on the inclined surface of the inverted V-shaped top surface, so that the light flame has a counteracting tendency against the rich flame on the side.

[0025] Another object of the present invention is to provide a thick-lean burner, comprising a plurality of fire bars, which are combined side by side and adopt the fire bar structure described above; when the thick-lean burner adopts an upper exhaust air outlet method, a wind shield is also arranged under the plurality of fire bars, and the wind shield has a plurality of air holes.

[0026] The present invention also provides the following application of the above-mentioned thick-thin burner on a water heater:

[0027] A domestic gas instantaneous water heater comprises the above-mentioned thick-thin burner, a water tank and an air outlet unit.

[0028] A gas heating hot water boiler comprises the above-mentioned thick-thin burner, a water tank and an air outlet unit.

[0029] A steam heat source machine, characterized by comprising the above-mentioned thick and thin burner, a water tank and an air outlet unit.

[0030] Compared with the prior art, the advantages of the present invention include at least:

[0031] (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 the structure adopts a single injection hole, rich-lean combustion diversion, and lean combustion supplementary air.

[0032] (2) On a single fire row, the combustion method adopts a "mountain"-shaped combustion method with light combustion in the middle and dense combustion on both sides. The dense combustion on both sides is oxygen-poor combustion, and the light combustion in the middle is oxygen-rich combustion. The dense combustion on both sides is used to consume the excess oxygen of the light combustion in the middle, thereby holding the light flame and preventing flameout. This makes the overall combustion more stable and improves the flame rigidity.

[0033] (3) A single ejection hole is used for air intake. Through the coordination of the Venturi tube, the drainage tube, and the flow equalization chamber, the dead angle of gas flow is reduced and the uniformity of the initial gas distribution in the length direction of the fire row is improved.

[0034] (4) The rich combustion outlet structure is arranged above the lean combustion outlet structure, and a lean combustion mixing chamber is arranged at the upper part of the inner shell, thereby extending the process of the gas for lean combustion entering the lean combustion mixing chamber, during which the gas and air are premixed. The lean combustion outlet structure and the rich combustion outlet structure are arranged staggered up and down, so that the gas flow of the rich and lean combustion is stable and uniform.

[0035] (5) An air intake gap is formed between the core shell and the inner shell, and an air drainage gap is formed between the inner shell and the outer shell. The air intake gap and the air drainage gap are connected through the air intake structure, thereby achieving mixing of supplementary air and light combustion gas in the air intake gap.

[0036] (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 construed as a limitation on the air intake structure of the present invention.

[0037] (7) The rich combustion gas outlet gap and the air guide gap are isolated from each other, which helps to completely prevent the supplementary air from interfering with the gas outlet for rich combustion and ensure the stability of the airflow in the rich combustion gas outlet gap. The lean combustion gas outlet structure preferably has an upward gas outlet, and the supplementary air and the gas are mixed in a nearly parallel flow during the rising process, so as to avoid the supplementary air from sealing the lean combustion gas outlet structure and hindering the smooth gas outlet of the lean combustion gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a front view of the core shell in the embodiment of the present invention;

[0039] Figure 2 A top view of a core shell in an embodiment of the present invention;

[0040] Figure 3 It is a right side view of the core shell in the embodiment of the present invention;

[0041] Figure 4 is a front view of the inner shell in an embodiment of the present invention;

[0042] Figure 5 is a top view of the inner shell in an embodiment of the present invention;

[0043] Figure 6 is a three-dimensional diagram of the inner shell in an embodiment of the present invention;

[0044] Figure 7 is a front view of a housing in an embodiment of the present invention;

[0045] Figure 8 is a top view of a housing in an embodiment of the present invention;

[0046] Fig. 9 It is a front view of the fire bar in the embodiment of the present invention;

[0047] Fig.10 A top view of a fire bar in an embodiment of the present invention;

[0048] Fig.11 for Fig. 9 Middle BB section view;

[0049] Fig.12 for Fig. 9 Middle DD section view;

[0050] Fig.13 for Fig. 9 Middle FF section view;

[0051] Fig.14 for Fig. 9 Middle EE section view;

[0052] Fig.15 A top view of a rich-lean burner in an embodiment of the present invention;

[0053] Fig.16 It is a front view of a rich-lean burner in an embodiment of the present invention;

[0054] Fig.17 for Fig.16 BB section view in;

[0055] In the figure, core shell 1, inner shell 2, outer shell 3, slow flow hole 4, venturi tube 11, drainage pipe 12, equal flow chamber 13, diversion chamber 14, closed top surface 15, outer protrusion 16, rich burn air outlet hole 17, lean burn air outlet hole 18, air intake chamber 21, lean burn mixing chamber 22, air intake gap 23, intake slope 24, air intake slit 25, lean fire hole 26, inner protrusion 27, rich burn air guide hole 28, inner convex strip 29, air drainage chamber 31, rich burn air outlet chamber 32, air drainage gap 33, rich burn air outlet gap 34, long convex strip 35, protrusion 36, rich fire hole 37. DETAILED DESCRIPTION

[0056] The present invention is further described in detail below in conjunction with the accompanying drawings. The embodiments are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention. The text description in this embodiment corresponds to the accompanying drawings, and the description of the orientation in the description is also based on the description of the accompanying drawings, and should not be understood as limiting the specific structure.

[0057] Example 1

[0058] This embodiment relates to a fire grate of a rich-lean burner, comprising a core shell 1, an inner shell 2, and an outer shell 3, which are arranged in sequence from the inside to the outside. The core shell 1, the inner shell 2, and the outer shell 3 are respectively formed by two symmetrical side plates connected together, and the connection method can be the edge wrapping of one side plate to the other side plate, or mutual butt welding.

[0059] like Figure 1-3 As shown, the core shell 1 includes an ejection channel, a flow equalization chamber 13, and a flow diversion chamber 14 arranged from bottom to top. Among the three, the flow equalization chamber 13 has the narrowest width, is open at the top and bottom, is connected to the flow diversion chamber 14 at the top, and is connected to the ejection channel at the bottom. 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-shape. The flow equalization chamber 13 has an arc-shaped deflection area and is approximately fan-shaped. It has an upper straight edge extending in the length 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 the goal of making the gas flow evenly on the straight edge of the flow equalization chamber 13. In order to give full play to the role of the venturi tube 11, the drainage pipe 12, and the flow equalization chamber 13 in evenly distributing gas, the two side plates of the core shell 1 are fitted to each other at the bottom and left and right sides of the three to eliminate airflow dead corners.

[0060] The flow diversion chamber 14 is used to realize the fuel 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 arranged at intervals along the length direction on the two side walls of the flow diversion chamber 14, respectively. 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, such as 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 up and down directions at a ratio of 1:2.

[0061] Specifically, the rich burn outlet structure includes an outer protrusion 16 formed from the inside to the outside on the side wall of the diverter chamber 14, and a rich burn outlet hole 17 formed by punching the end face of the outer protrusion 16. The lean burn outlet structure includes a convex hole directly punched from the inside to the outside on the side wall of the diverter chamber 14. The convex hole is preferably punched with the hole facing upward during the processing, and the convex hole formed in this way serves as the lean burn outlet hole 18.

[0062] like Figure 4-6 As shown, the inner shell 2 includes an air intake chamber 21 and a light combustion mixing chamber 22 arranged from bottom to top. The air intake chamber 21 is covered on the outside of the diverter chamber 14. The light combustion 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 light combustion mixing chamber 22 above. A light combustion hole 26 is provided on the top surface of the light combustion mixing chamber 22. 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 realizing that the air intake chamber 21 almost seals the bottom of the diverter chamber 14. A plurality of air intake slits 25 are provided on the intake slope 24. The air intake slits 25 are used as the air intake structure of the air intake gap 23.

[0063] The air intake gap 23 is connected to the light combustion outlet hole 18. The light combustion gas drawn out from the light combustion outlet hole 18 enters the air intake gap 23, is premixed with the air, and then enters the light combustion mixing chamber 22 upward from the air intake gap 23 for further mixing, and burns in the light flame hole 26 to form a light flame.

[0064] The core function of the inner shell 2 is to separate the rich and the lean combustion, so it is necessary to separate the rich and the lean combustion gas. Therefore, a number of gas guide structures are also provided on the side wall of the inner shell 2, and the several gas guide structures are in contact and conduction with the several rich combustion outlet structures in a one-to-one correspondence. Specifically, the several 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 formed by punching on the end face of the inner protrusion 27. The inner protrusion 27 and the end face of the outer protrusion 16 of the rich combustion outlet structure are against each other to form a contact seal, and the rich combustion gas guide hole 28 and the rich combustion outlet hole 17 are in one-to-one correspondence and conduction, thereby guiding the gas used for rich combustion to the outside of the inner shell 2.

[0065] In the present 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 surface of the inner convex strip 29. Structurally, the inner convex strip 29 is abutted against the end surface of the outer protrusion 16 of the rich combustion 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 plurality of slow flow holes 4 by a plurality of outer protrusions 16, so that the air intake gap 23 and the lean combustion mixing chamber 22 are connected up and down through the plurality of slow flow holes 4.

[0066] like Figure 7-8 As shown, the outer shell 3 covers the outer side of the inner shell 2, and the top of the outer shell 3 is open. The two side panels constituting the outer shell 3 are connected by a plurality of connecting strips at the top open position, including an air induction chamber 31 and a rich combustion outlet chamber 32 arranged from bottom to top. A downwardly open air induction gap 33 is formed between the air induction chamber 31 and the side wall of the air inlet chamber 21, and the air inlet structure, i.e., the air inlet slit 25, is located within the air induction gap 33. An upwardly open rich combustion outlet gap 34 is formed between the rich combustion outlet chamber 32 and the side wall of the lean combustion mixing chamber 22. A long convex strip 35 is formed on the side wall of the outer shell 3 from outside to inside, and the long convex strip 35 extends along the length direction. The long convex strip 35 contacts the outer wall of the inner shell 2, thereby separating the air induction gap 33 and the rich combustion outlet gap 34 from top to bottom so as to be close to non-conductive and preferably relatively blocked.

[0067] The rich combustion air guide hole 28 on the inner shell 2 is connected to the rich combustion outlet gap 34. A plurality of protrusions 36 extending from outside to inside are arranged at intervals along the length direction on the top of the side wall of the rich combustion outlet chamber 32. The protrusions 36 press against the side wall of the lean combustion mixing chamber 22 inwardly, thereby dividing the top of the rich combustion outlet gap 34 into a plurality of rich fire holes 37 arranged at intervals.

[0068] The bottom of the side wall of the air guide chamber 31 is formed into a concave-convex structure along the length direction. The spacing between the outer shells of adjacent fire rows of the burner is very narrow. The aforementioned "concave-convex structure" can prevent air from flowing upward from the gap between adjacent fire rows, and make the air tend to enter the air guide gap 33, thereby providing supplementary air for the light combustion mixing chamber 22.

[0069] The thick and thin combustion process of the above-mentioned fire row is as follows:

[0070] The gas entrained with air is evenly distributed to the diverter chamber 14 through the venturi tube 11, the drainage tube 12, and the equalizing chamber 13. The initial gas in the diverter chamber 14 enters the air intake gap 23 from the light combustion outlet hole 18 below, is premixed with the supplementary air entering the air intake gap 23 from the air intake slit 25, enters the light combustion mixing chamber 22 upward through the slow flow hole 4, and is mixed again, and finally burns at the light flame hole to form a light flame. The initial gas in the diverter chamber 14 enters the light combustion outlet gap 34 from the strong combustion outlet hole 17 and the strong combustion air guide hole 28 above, and finally burns at the strong flame hole to form a strong flame. The strong flame is located on both sides of the light flame, and the oxygen-poor strong flame is used to consume the excess oxygen in the light flame to avoid the light flame from flameout, thereby improving the flame rigidity and stabilizing the combustion, which is also helpful to improve the combustion efficiency of the gas as a whole.

[0071] Example 2

[0072] This embodiment relates to a thick-lean burner, comprising a plurality of fire bars, which are arranged side by side, and the fire bars are the fire bars described in Embodiment 1. When the thick-lean burner adopts an upper air extraction, i.e., a negative pressure air outlet, a wind shield is further provided under the plurality of fire bars, and air holes are provided on the wind shield for diversion.

[0073] Of course, the rich-lean burner of this embodiment can also adopt downward blowing, that is, positive pressure blowing. When positive pressure blowing is adopted, the wind shield plate should also be set below the multiple fire rows.

[0074] In addition, air outlet channels are retained between the fire bars, so that air flows are formed on both sides of each fire bar, which can cool the fire bars on the one hand and push the thick flames from the outside to the inside on the other.

[0075] Example 3

[0076] This embodiment relates to a water heater, such as a household gas instantaneous water heater, a gas heating water heater, or a steam heat source machine, comprising the thick-lean burner, a water tank, and an air outlet unit described in Embodiment 2. The air outlet unit may be an upper exhaust fan or a lower blowing fan. The water tank is located above the thick-lean burner.

[0077] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. A fire row of a thick and thin burner, characterized in that: Including heart shell, inner shell, outer shell, The core shell includes an ejection channel, a flow-equalizing chamber, and a flow-dividing chamber arranged from bottom to top. The flow-equalizing chamber has upper and lower openings, is connected to the flow-dividing chamber at the top, and is connected to the ejection channel at the bottom. The side wall of the flow-dividing 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; the plurality of lean combustion outlet structures have upwardly facing outlets; the flow-dividing chamber has a closed top surface, and the rich combustion outlet structures and lean combustion outlet structures respectively arranged on the two side walls of the flow-dividing chamber are symmetrical to each other, the rich combustion outlet structure on the same side wall is located above the lean combustion outlet structure, and a plurality of rich combustion outlet structures and a plurality of lean combustion outlet structures are staggered in the upper and lower directions; the rich combustion outlet structure includes an outer protrusion formed from the inside to the outside on the side wall of the flow-dividing chamber, and a rich combustion outlet hole formed by punching on the end face of the outer protrusion; the lean combustion outlet structure includes a convex hole directly punched from the inside to the outside on the side wall of the flow-dividing chamber, the orifice of the convex hole faces upward, and the convex hole serves as a lean combustion outlet hole; The inner shell cover is outside the diverter chamber, and includes an air intake chamber, a lean combustion mixing chamber, and a plurality of air guide structures arranged from bottom to top on the inner shell side wall, and 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 diverter chamber and outside the side wall of the diverter chamber, the air intake gap is in conduction with the plurality of lean combustion outlet structures, an air intake structure is provided at the bottom of the air intake gap, the air intake gap is further in conduction with the lean combustion mixing chamber upwards, and a lean combustion hole is provided on the top surface of the lean combustion mixing chamber; The outer shell cover is on the outside of the inner shell, and includes an air induction chamber and a rich combustion air outlet chamber arranged from bottom to top, a downwardly open air induction gap is formed between the air induction chamber and the side wall of the air inlet chamber, and the air inlet structure is located within the air induction gap; an upwardly open rich combustion air outlet gap is formed between the rich combustion air outlet chamber and the side wall of the lean combustion mixing chamber, the plurality of air guide structures are in communication with the rich combustion air outlet gap, and a rich fire hole is formed at the top of the rich combustion air outlet gap.

2. The fire bar according to claim 1, characterized in that: The air guide gap is not connected to the rich combustion air outlet gap, and the air guide gap is connected to the air intake gap through the air intake structure.

3. The fire bar according to claim 2, characterized in that: A long convex strip is formed on the side wall of the outer shell from outside to inside, and the long convex strip extends along the length direction. The long convex strip is in sealing contact with the outer wall of the inner shell, thereby separating the air induction gap and the rich combustion gas outlet gap from top to bottom to make them non-conductive.

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

5. The fire bar according to claim 1, characterized in that: The plurality of gas guide structures include an inner protrusion formed from the outside to the inside on the side wall of the inner shell, and a rich-burn gas guide hole formed by punching on the end face of the inner protrusion. The inner protrusion and the end face of the outer protrusion abut against each other to form a contact seal, and the rich-burn gas guide holes and the rich-burn gas outlet holes are connected one by one.

6. The fire bar according to claim 1, characterized in that: 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. The plurality of air guide structures are formed on the inner convex strip. 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.

7. The fire bar according to claim 1, characterized in that: The bottom of the side wall of the air intake chamber is retracted inward to form an air intake slope, and the bottom edge of the air intake slope is in sealing contact with the outer wall of the core shell, thereby achieving the air intake chamber's sealing wrapping of the bottom of the diversion chamber, and a number of air intake slits are arranged on the air intake slope, which serves as the air intake structure.

8. The fire bar according to claim 1, characterized in that: The bottom of the side wall of the air guide chamber is formed into a concave-convex structure along the length direction.

9. The fire bar according to claim 1, characterized in that: The top of the side wall of the rich combustion outlet chamber is provided with a plurality of protrusions extending from outside to inside at intervals along the length direction, and the protrusions press inwardly against the side wall of the light combustion mixing chamber, thereby dividing the top of the rich combustion outlet gap into a plurality of rich fire holes arranged at intervals.

10. The fire bar according to claim 1, characterized in that: The top surface of the light-burning mixing chamber is a plane or an inverted V-shaped top surface, and the light-burning hole is arranged on the inclined surface of the inverted V-shaped top surface.

11. A rich-lean burner, characterized in that: It comprises a plurality of fire bars which are combined side by side, and the fire bars are the fire bars as claimed in any one of claims 1 to 10; a wind shield is also arranged under the plurality of fire bars, and the wind shield has a plurality of wind holes.

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

13. A gas heating water heater, characterized in that it comprises the rich-lean burner, water tank and air outlet unit as claimed in claim 11.

14. A steam heat source machine, characterized in that: It comprises the rich-lean burner, water tank and air outlet unit as described in claim 11.

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