Fire bars, burner assemblies and hot water units

Abstract

An embodiment of the present invention provides a fire grate, a burner assembly, and a water heater, wherein the fire grate comprises: a fire grate body, a combustion plate provided on the fire grate body; an air intake pipe provided in the fire grate body, one end of the air intake pipe forming an air intake hole for receiving gas, and the other end connected to the combustion chamber through the combustion plate, the air intake hole and the combustion plate being provided on opposite sides of the fire grate body, a return air hole penetrating the side wall of the air intake pipe near one end of the air intake hole being provided, and the flue gas generated in the combustion chamber being able to flow into the air intake pipe through the return air hole. According to the solution of the present invention, by providing a return air hole at a position near the air intake hole in the air intake pipe, the return air gas is used to place the air intake pipe in a low-oxygen environment, thereby suppressing the generation of thermal nitrogen oxides to a certain extent, thereby achieving low nitrogen emissions.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of water heaters, and in particular to a fire strip, a burner assembly and a water heater. Background Art

[0002] At present, the national standard for low nitrogen emissions is no more than 70ppm (parts per million). In daily life, gas water heaters are very likely to produce a large amount of nitrogen oxides (NO x ), and the large-scale generation and emission of thermal nitrogen oxides will cause great pollution to the environment. Summary of the Invention

[0003] In order to solve at least one of the above technical problems, an object of an embodiment of the present invention is to provide a fire extinguisher.

[0004] Another object of an embodiment of the present invention is to provide a burner assembly having the above-mentioned fire strip.

[0005] Another object of an embodiment of the present invention is to provide a water heating device having the burner assembly.

[0006] To achieve the above-mentioned objectives, an embodiment of the first aspect of the present invention provides a fire grate piece, comprising: a fire grate body, on which a combustion plate is provided; an air intake pipe, which is arranged in the fire grate body, and one end of the air intake pipe forms an air intake hole for receiving fuel gas, and the other end is connected to the combustion chamber through the combustion plate, the air intake hole and the combustion plate are arranged on opposite sides of the fire grate body, and a return air hole passing through the side wall of the air intake pipe near one end of the air intake hole is provided, so that the smoke generated in the combustion chamber can flow into the air intake pipe through the return air hole.

[0007] The fire block provided by the present invention includes a fire block body and an air intake pipe. A combustion plate is provided on the fire block body. Generally, flames burn upward, so the combustion plate can be placed on top of the fire block body. That is, the flames generated by the fire block need to pass through the combustion plate. The combustion plate can stabilize the flames and ensure a more even distribution of the flames.

[0008] In addition, an air intake hole for receiving gas is formed at one end of the air intake pipe disposed within the fire grate body, and the other end is connected to the combustion chamber via the combustion plate. Since the air intake hole and the combustion plate are located on opposite sides of the fire grate body, when the combustion plate is at the top of the fire grate, the air intake hole can be located at the bottom of the fire grate. After the gas and combustion air enter the air intake pipe through the air intake hole, they are first premixed, that is, initially mixed. Due to the continuous injection of gas, the air flow will continuously flow inward along the air intake hole, thus always moving toward the end away from the air intake hole, ignited by the ignition part in the fire grate, and then burned in the combustion chamber.

[0009] It should be particularly emphasized that since the air intake hole and the combustion plate are arranged on opposite sides of the fire grate body, the air intake hole is located at a position away from the combustion plate in the air intake pipe, and the distance between the air intake hole and the combustion plate can be set to be maximized, which is conducive to gas mixing.

[0010] On the basis that the combustion plate is set above the fire grate body, the air inlet will be set below. The air intake through the bottom can better meet the use scenario of connecting gas from the bottom and also reduce the length of the pipeline.

[0011] Of course, it is also possible that the combustion plate is arranged on the side of the fire grill body and the air inlet is arranged on the other side, for example, the two are respectively arranged on the left and right sides or the front and back sides, which will also meet different usage scenarios.

[0012] Furthermore, the sidewall of the intake pipe is provided with a return air hole near the intake port, and the return air hole extends through the sidewall of the intake pipe. As the fuel gas and combustion-supporting air continuously burn within the combustion chamber, a large amount of flue gas is generated. This flue gas, of course, includes some fuel gas and combustion-supporting gas that have not yet burned, some carbon monoxide and other flammable gases or particles derived from incomplete combustion, and some chemically stable gases or particles. This flue gas can re-enter the intake pipe through the return air hole, where it mixes with the fuel gas and combustion-supporting gas before being re-combusted. Because the return air hole is located on the sidewall of the intake pipe, the flue gas that flows into the intake pipe through the return air hole is not discharged, thus achieving internal recirculation of the flue gas. Since the flue gas generated by combustion has a very low oxygen content, its entry into the intake pipe reduces the oxygen content of the gas within the intake pipe, reducing the completeness of combustion during the combustion of the fire slices and, in turn, lowering the flame temperature of the fire slices. Since the flame temperature of the fire bar is reduced, the nitrogen oxides (NO X ), thereby reducing the emission of nitrogen oxides from the gas heating components to reduce the pollution of nitrogen oxides to the environment.

[0013] Specifically, the intake pipe filled with fuel gas and combustion-supporting gas is mixed with recycled flue gas, which reduces the oxygen concentration of the combustible mixture. The combustion heat release rate will be reduced in the case of low-oxygen combustion, and the phenomenon of instantaneous high-temperature heat release in small volumes in traditional combustion will no longer exist, that is, the combustion heat release temperature is effectively controlled. Since thermal nitrogen oxides are positively correlated with temperature, the low combustion heat release temperature will also reduce the amount of thermal nitrogen oxides generated. In addition, because in a low-oxygen environment, incomplete combustion may increase, resulting in an increase in the amount of carbon monoxide. Since the amount of thermal nitrogen oxides is negatively correlated with the amount of carbon monoxide, the amount of thermal nitrogen oxides generated is reduced. Therefore, by setting a return air hole and using the returned flue gas to put the intake pipe in a low-oxygen environment, the generation of thermal nitrogen oxides can be suppressed to a certain extent, thereby achieving low nitrogen emissions. In addition, due to the setting of the return air hole, the flue gas carrying carbon monoxide can be discharged back into the intake pipe, so that when it is burned again, the carbon monoxide can be burned to form carbon dioxide, reducing safety hazards.

[0014] Furthermore, because the return air hole is close to the air inlet hole, that is, the return air hole is also located in the air inlet pipe away from the combustion plate, after the fuel gas and combustion-supporting gas enter the air inlet pipe through the air inlet hole, the smoke will then enter the interior of the air inlet pipe through the return air hole, thereby forming a mixed gas with a low oxygen environment in the air inlet pipe near the air inlet hole. Since both the return air hole and the air inlet hole are located away from the combustion plate, the fuel gas, combustion-supporting gas, and smoke have a longer time to mix, mixing more thoroughly, thereby making it easier to create a low oxygen environment inside the air inlet pipe.

[0015] Furthermore, the return air hole is opened through the side wall of the air inlet pipe, and no additional structure is required, so the processing of the return air hole is relatively simple. Specifically, the number of return air holes can be multiple, so that more flue gas can enter the air inlet pipe at the same time and mix with the fuel gas and the combustion-supporting gas.

[0016] Furthermore, the return air hole can be opened at an angle on the side wall of the air inlet pipe, and the position of the return air hole at one end of the outer wall of the air inlet pipe is lower than that at the end of the inner wall of the air inlet pipe, that is, the return air hole is set to be inclined upward from the outside to the inside of the air inlet pipe, so that after the flue gas enters the interior of the air inlet pipe through the return air hole, the flue gas itself will also move toward the end away from the air inlet hole, and will not move against the airflow formed by the fuel gas and the combustion-supporting gas.

[0017] Alternatively, the air return hole is a conical hole, and the large end of the conical hole is on the outer wall of the air inlet pipe, and the small end is on the inner wall of the air inlet pipe, that is, the aperture of the conical hole gradually decreases from the outside of the air inlet pipe to the inside of the air inlet pipe. Since the flow velocity is inversely proportional to the cross-sectional area, the flow velocity of the flue gas gradually becomes faster in the process of entering the interior of the air inlet pipe through the air return hole, which is conducive to the mixing of the flue gas, the fuel gas and the combustion-supporting gas.

[0018] In addition, the above technical solution provided by the present invention may also have the following additional technical features:

[0019] In the above technical solution, the air intake pipe includes: an air intake portion, an air intake hole is formed at one end of the air intake portion away from the combustion plate; an expansion portion, connected to the air intake portion, and the combustion gas flows from the air intake portion into the air intake pipe and flows into the combustion chamber through the expansion portion.

[0020] In this technical solution, the intake pipe includes an intake portion and an expansion portion connected to each other, and the intake hole is located at the end of the intake portion away from the combustion plate. The diameter of the expansion portion can be larger than that of the intake portion, that is, the cross-sectional area of ​​the expansion portion relative to the normal plane of the intake pipe axis is larger than the cross-sectional area of ​​the intake portion. Under the condition that the gas flow rate remains unchanged, according to the formula that the flow rate is equal to the flow rate divided by the area, the flow rate of the gas after entering the expansion portion will be lower than the flow rate in the intake portion. The lower flow rate not only helps the gas to diffuse evenly onto the combustion plate, but also improves the mixing efficiency between air and gas, so that the mixed gas can be maintained in a low-oxygen environment. By controlling the temperature and increasing the amount of carbon monoxide, the generation of thermal nitrogen oxides is suppressed, thereby achieving low nitrogen emissions.

[0021] Furthermore, a plurality of expansion parts can be provided, and preferably, the diameters of the plurality of expansion parts are the same, or the diameters of the plurality of expansion parts are different and vary in a stepwise manner. By providing a plurality of expansion parts, the gases can be mixed more fully.

[0022] In the above technical solution, the air intake pipe further includes a diverter portion provided in the expansion portion, and the diverter portion can separate the flow path of the gas flowing from the air intake portion to the expansion portion.

[0023] In this technical solution, a diverter is provided in the intake pipe to separate the flow path of the gas. By providing the diverter, the gas flows from the intake part into the various small channels formed by the diverter, making it easier to mix the mixed gas so that the mixed gas is in a low-oxygen environment.

[0024] Furthermore, the length direction of the small channel formed by the diversion part in the expansion part may be inconsistent with the length direction of the air inlet part, that is, the flow direction of the gas when passing through the small channel is inconsistent with that in the air inlet part, thereby forming a vortex airflow, which can make the gas mixing more complete.

[0025] Generally speaking, the surface area of ​​the combustion plate is larger than the area of ​​the cross section of the intake pipe perpendicular to the axis. Therefore, it is necessary to set a diversion part to guide the gas in the intake pipe to various positions of the combustion plate, so that after ignition through the ignition part of the fire row piece, the generated flame can be spread over various positions of the combustion plate.

[0026] In the above technical solution, the direction from the air inlet portion to the expansion portion is perpendicular to the plane where the combustion plate is located.

[0027] In this technical solution, by limiting the direction from the air intake portion to the expansion portion to be perpendicular to the plane of the combustion plate, that is, the overall flow direction of the fluid in the air intake pipe is perpendicular to the combustion plate, the distance between the air intake hole, the return air hole and the combustion plate can be maximized, which helps to fully mix the fuel gas, combustion-supporting gas and return flue gas, so that the mixed gas is in a low-oxygen environment to reduce the emission of nitrogen oxides.

[0028] In the above technical solution, an expansion section is provided at one end of the air inlet away from the expansion section, and the cross-sectional area of ​​at least part of the expansion section is larger than the cross-sectional area of ​​the air inlet.

[0029] In this technical solution, by arranging the expansion section at one end of the air inlet part away from the expansion part, and limiting the cross-sectional area of ​​at least a part of the expansion section to be larger than the cross-sectional area of ​​the air inlet part, when the gas flow rate remains unchanged, the flow velocity is inversely proportional to the cross-sectional area, that is, the gas flows slower when passing through the expansion section with a larger cross-sectional area. The slower gas flow rate helps to fully mix the fuel gas, combustion-supporting gas and flue gas, thereby reducing the emission of nitrogen oxides.

[0030] In the above technical solution, the diameter of at least part of the expanded pipe section gradually decreases in the direction from the air inlet portion to the expansion portion.

[0031] In this technical solution, the diameter of the part with a larger cross-sectional area in the expanded section gradually decreases in the direction from the air inlet to the expanded section, that is, the flow velocity of the gas gradually increases when it flows out of the expanded section and flows toward the expanded section, and the change process is gradual, thereby reducing the sudden change in the flow velocity of the mixed gas formed after the gas and air are mixed, thereby reducing unnecessary flow resistance.

[0032] In the above technical solution, the air intake pipe further includes: a guide platform, which is arranged in the air intake portion and close to the air intake hole. The diameter of the guide platform gradually decreases from the air intake portion to the expansion portion.

[0033] In this technical solution, a guide table is provided in the air intake section near the air intake hole, and the tube diameter of the guide table gradually decreases in the direction from the air intake section to the expansion section. When the flow rate remains unchanged, the flow velocity is inversely proportional to the cross-sectional area passed through. Therefore, by providing the guide table, the flow velocity of the gas gradually increases in the process of flowing from the air intake section to the expansion section. On the one hand, on the basis of gradually increasing the flow velocity, an airflow from the air intake hole to the combustion plate can be formed, thereby having the effect of drainage or diversion. On the other hand, due to the gradual increase in the flow velocity, a negative pressure will be formed in the air intake pipe, which is also conducive to driving the smoke in the return air hole to flow back to the air intake pipe under the Venturi effect.

[0034] In the above technical solution, the air return hole extends to the end surface of the air inlet hole to form an air return gap.

[0035] In this technical solution, the return air hole extends to the end face of the air inlet hole to form an air return gap, which increases the channel for the flue gas to enter the air inlet pipe. That is, the flue gas generated during the combustion process can more easily enter the air inlet pipe to form an internal circulation, so that the mixed gas in the air inlet pipe can be maintained in a low-oxygen environment.

[0036] In the above technical solution, the air intake pipe further includes: a guide plate, one end of which is arranged corresponding to the air return hole, and the other end of which is bent and extended outward along the radial direction of the air intake pipe.

[0037] In this technical solution, one end of the guide plate is positioned corresponding to the return air hole, while the other end curves and extends radially outward along the intake pipe. Furthermore, the guide plate can be positioned with its larger end away from the combustion plate, that is, tilted downward from its smaller end toward its larger end. Before the smoke generated by combustion flows back into the intake pipe through the return air hole, the guide plate will initially converge the smoke. The guide plate then guides the smoke upward along the inner wall of the guide plate, through the return air hole, and into the intake pipe, forming an internal recirculation or internal circulation.

[0038] Among them, one end of the guide plate is set corresponding to the return air hole. One end of the guide plate can be directly connected to the hole wall of the return air hole, or one end of the guide plate can be connected to the pipe wall of the air inlet pipe around the return air hole. It is only necessary to guide the smoke through the return air hole and return to the air inlet pipe under the action of the guide plate.

[0039] In the above technical solution, there are multiple air return holes.

[0040] In this technical solution, by providing a plurality of return air holes, the return flue gas can more easily enter the interior of the air inlet pipe.

[0041] Furthermore, the plurality of air return holes may be evenly arranged along the circumference of the air inlet pipe, or different numbers of air return holes may be flexibly arranged at corresponding positions according to the amount of smoke in a local area.

[0042] In the above technical solution, the combustion plate is arranged on the top of the fire grate body, and a combustion hole group is provided on the side of the combustion plate away from the air inlet pipe.

[0043] In this technical solution, the combustion plate is arranged on the top of the fire grate body. On this basis, the air intake hole is arranged at the bottom of the fire grate body. By taking in air from the bottom, it is more conducive to meeting the needs of the use scenario of connecting gas from the bottom, and also reduces the length of unnecessary pipelines connecting gas. In addition, by providing a combustion hole group on the side away from the air intake pipe, the generated flame can be spread throughout various positions of the combustion plate.

[0044] In the above technical solution, the combustion hole group includes at least one combustion fire hole, and the shape of the combustion fire hole is rectangular.

[0045] In this technical solution, the combustion hole group may include one, two or more combustion holes. When multiple combustion holes are provided, the generated flame can form multiple workstations simultaneously through the combustion holes.

[0046] Furthermore, the shape of the combustion fire hole is rectangular, the generated flame is more regular, and the flame can pass through the combustion fire hole more easily.

[0047] An embodiment of the second aspect of the present invention provides a burner assembly, comprising: a shell, a combustion chamber is provided in the shell; a plurality of fire strips in any of the above embodiments, the other end of the air inlet pipe of the fire strip being connected to the combustion chamber through a combustion plate; a combustion nozzle, which is arranged corresponding to the air inlet hole of the fire strip, and the combustion nozzle can spray gas into the air inlet hole.

[0048] In this technical solution, the burner assembly includes a housing, a flame strip, and a combustion nozzle. A combustion chamber is located within the housing, which is the space where the fuel gas and combustion-supporting gas burn. The other end of the intake pipe in the flame strip is connected to the combustion chamber. Combustible gas enters the intake pipe through the intake hole and then flows along the extension of the intake pipe to the combustion chamber. After being ignited by the ignition unit, the fuel gas and combustion-supporting gas burn.

[0049] In addition, the combustion nozzle is arranged corresponding to the air inlet hole, and the combustion nozzle continuously sprays high-pressure and high-kinetic energy gas into the air inlet hole. On the one hand, under the action of the combustion nozzle, the air in the shell can also flow into the air inlet pipe under the action of negative pressure. The gas will drive the flue gas and gas at the return air port into the air inlet channel, thereby reducing the oxygen content in the gas channel. On the other hand, it can form an airflow from the air inlet hole to the combustion plate, driving the flue gas entering the air inlet pipe from the return air hole to move toward the combustion plate to form an internal circulation.

[0050] In the above technical solution, a smoke channel is formed between the fire row slice and the shell; and / or a smoke channel is formed between any two adjacent fire row slices among the multiple fire row slices.

[0051] In this technical solution, when a fire row piece is provided in the shell, a smoke channel is formed between the fire row piece and the shell, that is, the smoke generated in the combustion process will pass through the smoke channel and enter the air inlet pipe at the return air port; when two or more fire rows are provided in the shell, a smoke channel will be formed between the shell and each fire row piece and between any two adjacent fire row pieces, for the smoke generated in the combustion process to pass through, so as to form an internal circulation of the smoke.

[0052] In addition, the embodiment of the burner assembly provided by the present invention has all the beneficial effects of the above-mentioned first embodiment because it is provided with the fire strip in any of the above-mentioned technical solutions, which will not be repeated here.

[0053] An embodiment of the third aspect of the present invention provides a water heating device, comprising: a shell assembly, in which a water tank is provided; and a burner assembly in any of the above embodiments, which is provided in the shell assembly corresponding to the water tank.

[0054] The water heater proposed in the present invention includes a shell assembly, a water tank and a burner assembly disposed within the shell assembly. Both the water tank and the burner assembly are disposed within the shell assembly. Furthermore, the water tank and the burner assembly are disposed in correspondence with each other, and the water tank can be positioned above, below, or to the side of the burner assembly. The burner assembly heats the water in the water tank, providing hot water for the user at any time.

[0055] In addition, the embodiment of the water heating device provided by the present invention has all the beneficial effects of the above-mentioned first embodiment because it is provided with the burner assembly in any of the above-mentioned technical solutions, which will not be repeated here.

[0056] Additional aspects and advantages of embodiments of the present invention will become apparent in the following description or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It shows a schematic structural diagram of a fire row according to an embodiment of the present invention;

[0058] Figure 2 A schematic structural diagram of a burner assembly according to an embodiment of the present invention is shown;

[0059] Figure 3 It shows a schematic structural diagram of multiple fire strips according to an embodiment of the present invention;

[0060] Figure 4 shows an enlarged structural schematic diagram of an air return hole according to one embodiment of the present invention;

[0061] Figure 5 shows an enlarged structural schematic diagram of an air return hole according to another embodiment of the present invention;

[0062] Figure 6 shows an enlarged structural schematic diagram of an air return hole according to another embodiment of the present invention;

[0063] Figure 7 A schematic structural diagram of a burner assembly according to another embodiment of the present invention is shown;

[0064] Figure 8 Shown Figure 6 A schematic diagram of the enlarged structure of the air return hole with a guide plate;

[0065] Figure 9 A schematic structural diagram of a burner assembly according to another embodiment of the present invention is shown;

[0066] Figure 10 Shown Figure 9 Schematic diagram of the enlarged structure of the middle air return gap;

[0067] Figure 11 shows a top view of a burner assembly according to one embodiment of the present invention;

[0068] Figure 12 A schematic structural diagram of a water heater according to an embodiment of the present invention is shown;

[0069] Figure 13 A schematic structural diagram of a water heater according to an embodiment of the present invention is shown;

[0070] Figure 14 A schematic structural diagram of a water heater according to an embodiment of the present invention is shown;

[0071] Figure 15 A schematic structural diagram of a water heater according to an embodiment of the present invention is shown.

[0072] in, Figures 1 to 15 The corresponding relationship between the reference numerals and component names is as follows:

[0073] 1: Shell; 2: Fire grate body; 3: Combustion plate; 4: Air inlet pipe; 41: Air inlet hole; 42: Return air hole; 43: Air inlet section; 44: Expansion section; 45: Diversion section; 46: Pipe expansion section; 47: Guide platform; 48: Guide plate; 49: Return air gap; 5: Smoke duct; 6: Combustion hole group; 61: Combustion fire hole; 7: Combustion nozzle; 8: Shell assembly; 81: Partition; 82: Air inlet channel; 9: Water tank; 10: Return air pipe; 11 Exhaust pipe; 12: Fan; 13: Combustion chamber. DETAILED DESCRIPTION

[0074] In order to more clearly understand the above-mentioned purposes, features and advantages of the embodiments of the present invention, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features therein can be combined with each other in the absence of conflict.

[0075] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the embodiments of the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0076] Refer to the following Figures 1 to 15The present invention provides a fire strip, a burner assembly and a water heater according to some embodiments of the present invention.

[0077] Example 1

[0078] like Figure 1 and Figure 2 As shown, a fire block provided by one embodiment of the present invention includes a fire block body 2 and an air inlet pipe 4. A combustion plate 3 is provided on the fire block body 2. Generally speaking, flames burn upward, so the combustion plate 3 is placed on top of the fire block body. This means that the flames generated by the fire block must pass through the combustion plate 3. The combustion plate 3 stabilizes the flames and ensures a more even distribution of the flames.

[0079] In addition, an air intake hole 41 for receiving gas is formed at one end of the air intake pipe 4 within the fire grate body 2, and the other end is connected to the combustion chamber 13 through the combustion plate 3. The air intake hole 41 and the combustion plate 3 are located on opposite sides of the fire grate body 2, that is, the air intake hole 41 is located at the bottom of the fire grate. After the gas and combustion air enter the air intake pipe 4 through the air intake hole 41, they are first premixed, that is, they undergo initial mixing. Due to the continuous injection of gas, the airflow will continuously flow inward along the air intake hole 41, always moving toward the end away from the air intake hole 41, ignited by the ignition part in the fire grate, and then burned in the combustion chamber 13.

[0080] It should be particularly emphasized that since the air inlet hole 41 and the combustion plate 3 are arranged on opposite sides of the fire bar body, the air inlet hole 41 is located at a position of the air inlet pipe 4 away from the combustion plate 3, and the distance between the air inlet hole 41 and the combustion plate 3 can be set to be maximized, which is conducive to gas mixing.

[0081] On the basis that the combustion plate 3 is arranged above the fire grate body, the air inlet 41 is arranged below. The air intake through the bottom can better meet the use scenario of connecting the gas from the bottom and also reduce the length of the pipeline.

[0082] Furthermore, the side wall of the air intake pipe 4 is provided with an air return hole 42 near the air intake hole 41, and the air return hole 42 penetrates the side wall of the air intake pipe 4. As the fuel gas and combustion-supporting air continue to burn in the combustion chamber 13, a large amount of smoke will be generated in the process. Of course, the smoke here includes a portion of the fuel gas and combustion-supporting gas that have not yet burned, another portion is carbon monoxide and other flammable gases or particles derived from incomplete combustion, and another portion is gas or particles with relatively stable chemical properties. These smoke gases can enter the interior of the air intake pipe 4 again through the air return hole 42, mix with the fuel gas and combustion-supporting gas, and then burn again. Since the air return hole 42 is provided on the side wall of the air intake pipe 4, the smoke that flows into the air intake pipe 4 through the air return hole 42 is not discharged to the outside, thereby realizing the internal recirculation of the smoke, that is, the internal circulation. Since the smoke produced by combustion contains very low oxygen, the smoke will reduce the oxygen content of the gas in the intake pipe 4 after entering the intake pipe 4, which will reduce the degree of combustion of the fire slices, and thus reduce the flame temperature of the fire slices. As a result, the flame temperature of the fire slices is reduced, thus reducing the nitrogen oxides (NO X ), thereby reducing the emission of nitrogen oxides from the gas heating components to reduce the pollution of nitrogen oxides to the environment.

[0083] Specifically, the intake pipe 4, which is filled with fuel gas and combustion-supporting gas, is mixed with recycled flue gas, which reduces the oxygen concentration of the combustible mixture. The combustion heat release rate is reduced in low-oxygen combustion, and the phenomenon of instantaneous high-temperature heat release in small volumes in traditional combustion is eliminated. This effectively controls the combustion heat release temperature. Since thermal nitrogen oxides are positively correlated with temperature, a low combustion heat release temperature also reduces the amount of thermal nitrogen oxides generated. Furthermore, in a low-oxygen environment, incomplete combustion may increase, leading to an increase in the amount of carbon monoxide. Since the amount of thermal nitrogen oxides is negatively correlated with the amount of carbon monoxide, the amount of thermal nitrogen oxides generated is reduced. Therefore, by providing the return air hole 42 and utilizing the returned flue gas to place the intake pipe 4 in a low-oxygen environment, the generation of thermal nitrogen oxides can be suppressed to a certain extent, thereby achieving low nitrogen emissions. Furthermore, due to the provision of the return air hole, the flue gas carrying carbon monoxide can be discharged back into the intake pipe 4, so that when it is burned again, the carbon monoxide can be burned to form carbon dioxide, reducing safety hazards.

[0084] Furthermore, since the air return hole 42 is close to the air inlet hole 41, that is, the air return hole 42 is also located at a position of the air inlet pipe 4 away from the combustion plate 3, after the fuel gas and the combustion-supporting gas enter the air inlet pipe 4 through the air inlet hole 41, the smoke will then enter the interior of the air inlet pipe 4 through the air return hole 42, thereby forming a mixed gas with a low oxygen environment at a position of the air inlet pipe 4 close to the air inlet hole 41. Since the air return hole 42 and the air inlet hole 41 are both located at a position away from the combustion plate 3, the fuel gas, the combustion-supporting gas, and the smoke have a longer time to mix, and the mixing is more complete, thereby making it easier to create a low oxygen environment inside the air inlet pipe 4.

[0085] Furthermore, the air return hole 42 is opened through the side wall of the air inlet pipe 4 without any additional structure, and the processing of the air return hole 42 is relatively simple.

[0086] Furthermore, the return air hole 42 is obliquely opened on the side wall of the air inlet pipe 4, and the position of the return air hole 42 at one end of the outer wall of the air inlet pipe 4 is lower than that at one end of the inner wall of the air inlet pipe 4, that is, the return air hole 42 is inclined upward from the outside of the air inlet pipe 4 to the inside, so that after the flue gas enters the interior of the air inlet pipe 4 through the return air hole 42, the flue gas itself will also move toward the end away from the air inlet hole 41, and will not move against the airflow formed by the fuel gas and the combustion-supporting gas.

[0087] Alternatively, the air return hole 42 is a conical hole, and the large end of the conical hole is on the outer wall of the air inlet pipe 4, and the small end is on the inner wall of the air inlet pipe 4, that is, the aperture of the conical hole gradually decreases from the outside of the air inlet pipe 4 to the inside of the air inlet pipe 4. Since the flow rate is inversely proportional to the cross-sectional area, the flow rate of the flue gas gradually becomes faster in the process of entering the interior of the air inlet pipe 4 through the air return hole 42, which is conducive to the mixing of the flue gas, the fuel gas and the combustion-supporting gas.

[0088] In another embodiment, the combustion plate 3 can be arranged on the side of the fire bar body, and the air inlet 41 can be arranged on the other side. For example, the two are arranged on the left and right sides or the front and back sides respectively, which can also meet different usage scenarios and be flexibly arranged according to actual needs.

[0089] In another embodiment, there may be multiple air return holes 42 so that more flue gas can enter the air inlet pipe 4 at the same time and mix with the fuel gas and the combustion-supporting gas.

[0090] Example 2

[0091] like Figure 2As shown, a burner assembly provided by one embodiment of the present invention includes a shell 1, a fire row piece in the above embodiment, and a combustion nozzle 7. Among them, a combustion chamber 13 is provided in the shell 1, and the combustion chamber 13 is a space for combustion of fuel gas and combustion-supporting gas. A fire row piece is provided, and is detachably connected to the inside of the shell 1. The other end of the air intake pipe 4 in the fire row piece is connected to the combustion chamber 13, and the combustible gas enters the air intake pipe 4 through the air intake hole 41, and then flows to the combustion chamber 13 along the extension direction of the air intake pipe 4. After ignition by the ignition part, the fuel gas and combustion-supporting gas are burned. A smoke channel 5 is formed between the fire row piece and the shell 1, that is, the smoke formed during the combustion process will pass through the smoke channel 5 and enter the air intake pipe 4 at the return air hole 42.

[0092] In addition, the combustion nozzle 7 is arranged corresponding to the air inlet hole 41, and the combustion nozzle 7 continuously sprays high-pressure and high-kinetic energy fuel gas into the air inlet hole 41. On the one hand, under the action of the combustion nozzle 7, the air in the shell 1 can also flow into the air inlet pipe 4 under the action of negative pressure. The fuel gas will drive the flue gas and fuel gas at the return air hole 42 into the air inlet pipe 4, thereby reducing the oxygen content in the air inlet pipe 4. On the other hand, an airflow can be formed from the air inlet hole 41 to the combustion plate 3, driving the flue gas entering the air inlet pipe 4 from the return air hole 42 to move toward the combustion plate 3 to form an internal circulation.

[0093] As the fuel gas and combustion-supporting air continue to burn in the combustion chamber, a large amount of flue gas is generated. This flue gas, of course, includes some fuel gas and combustion-supporting gas that have not yet burned, some carbon monoxide and other flammable gases or particles derived from incomplete combustion, and some chemically stable gases or particles. This flue gas can re-enter the interior of the intake pipe 4 through the return air hole 42, where it mixes with the fuel gas and combustion-supporting gas and then burns again, thus achieving internal circulation.

[0094] Furthermore, since the return air hole 42 is close to the air inlet hole 41, that is, the return air hole 42 is also located at a position of the air inlet pipe 4 away from the combustion plate 3, after the flue gas enters the air inlet pipe 4 from the return air hole 42, it can be more fully mixed with the fuel gas and the combustion-supporting gas under the drive of the airflow, that is, the entire air inlet pipe 4 is in an environment with a low oxygen concentration, so that not only the heat release rate is low during combustion, but also the generation of thermal nitrogen oxides can be effectively suppressed; and in a low-oxygen environment, sufficient fuel will increase incomplete combustion, that is, the generation of carbon monoxide will increase. Since carbon monoxide and nitrogen oxides are negatively correlated, the increase in the amount of carbon monoxide can also inhibit thermal nitrogen oxides to a certain extent, thereby achieving low nitrogen emissions.

[0095] The above-mentioned flue gas includes a part of the fuel gas and combustion-supporting gas that have not yet had time to burn, another part is carbon monoxide and other derived combustible gases or particles produced by incomplete combustion, and another part is gas or particles with relatively stable chemical properties. These flue gases can enter the interior of the intake pipe again through the return air hole to mix with the fuel gas and combustion-supporting gas and then burn again. Since the return air hole is provided on the side wall of the intake pipe, the flue gas flowing into the intake pipe through the return air hole is not discharged to the outside, thus realizing the internal reflux of the flue gas, that is, internal circulation. Since the oxygen content in the flue gas produced by combustion is very low, the oxygen content of the gas in the intake pipe will be reduced after entering the intake pipe, which will reduce the degree of combustion of the burner during combustion, thereby reducing the flame temperature of the burner. In addition, since the flame temperature of the burner is reduced, the nitrogen oxides (i.e. NO X ), thereby reducing the emission of nitrogen oxides from the gas heating components to reduce the pollution of nitrogen oxides to the environment.

[0096] Furthermore, the multiple air return holes 42 are all cylindrical holes, and the axis of each air return hole 42 is perpendicular to the axis of the air inlet pipe 4 .

[0097] It should be noted that the fire bar body 2 and the shell 1 can be detachably connected by a flange connection.

[0098] In another embodiment, the fire strip is fixedly connected to the housing 1 .

[0099] In another embodiment, Figure 3 As shown, two or more fire bars are provided in the shell 1, and a smoke channel 5 is formed between the shell 1 and each fire bar and between any two adjacent fire bar plates for the smoke generated during the combustion process to pass through, so as to form an internal circulation of the smoke.

[0100] Example 3

[0101] like Figure 6 As shown, a burner assembly provided by one embodiment of the present invention includes a shell 1, a fire row piece in any of the above embodiments, and a combustion nozzle 7. A combustion chamber 13 is provided in the shell 1, and the combustion chamber 13 is a space for combustion of fuel gas and combustion-supporting gas. A fire row piece is provided, and is detachably connected to the inside of the shell 1. The other end of the air intake pipe 4 in the fire row piece is connected to the combustion chamber 13, and the combustible gas enters the air intake pipe 4 through the air intake hole 41, and then flows to the combustion chamber 13 along the extension direction of the air intake pipe 4. After ignition by the ignition part, the fuel gas and combustion-supporting gas are burned. A smoke channel 5 is formed between the fire row piece and the shell 1, that is, the smoke generated during the combustion process will pass through the smoke channel 5 and enter the air intake pipe 4 at the return air hole 42.

[0102] In addition, the combustion nozzle 7 is arranged corresponding to the air inlet hole 41, and the combustion nozzle 7 continuously sprays high-pressure and high-kinetic energy fuel gas into the air inlet hole 41. On the one hand, under the action of the combustion nozzle 7, the air in the shell 1 can also flow into the air inlet pipe 4 under the action of negative pressure. The fuel gas will drive the flue gas and fuel gas at the return air hole 42 into the air inlet pipe 4, thereby reducing the oxygen content in the air inlet pipe 4. On the other hand, an airflow can be formed from the air inlet hole 41 to the combustion plate 3, driving the flue gas entering the air inlet pipe 4 from the return air hole 42 to move toward the combustion plate 3 to form an internal circulation.

[0103] Furthermore, a plurality of return holes 42 are provided on the side wall of the intake pipe 4 near the intake hole 41, allowing smoke generated in the combustion chamber to flow into the intake pipe 4 through the return holes 42. A smoke channel 5 is formed between the fire grate body 2 and the shell 1, allowing smoke generated during the combustion process to pass through the smoke channel 5 and enter the intake pipe 4 at the return holes 42.

[0104] Among them, the return air hole 42 is a conical hole, and the large end of the conical hole is on the outer wall of the intake pipe 4, and the small end is on the inner wall of the intake pipe 4, that is, the aperture of the conical hole gradually decreases from the outside of the intake pipe 4 to the inside of the intake pipe 4. Since the flow rate is inversely proportional to the cross-sectional area, the flow rate of the flue gas gradually becomes faster in the process of entering the interior of the intake pipe 4 through the return air hole 42, which is conducive to the mixing of the flue gas, fuel gas and combustion-supporting gas.

[0105] Example 4

[0106] like Figure 5 As shown, a burner assembly provided by one embodiment of the present invention includes a shell 1, a fire row piece in any of the above embodiments, and a combustion nozzle 7. A combustion chamber 13 is provided in the shell 1, and the combustion chamber 13 is a space for combustion of fuel gas and combustion-supporting gas. A fire row piece is provided, and is detachably connected to the inside of the shell 1. The other end of the air intake pipe 4 in the fire row piece is connected to the combustion chamber 13, and the combustible gas enters the air intake pipe 4 through the air intake hole 41, and then flows to the combustion chamber 13 along the extension direction of the air intake pipe 4. After ignition by the ignition part, the fuel gas and combustion-supporting gas are burned. A smoke channel 5 is formed between the fire row piece and the shell 1, that is, the smoke generated during the combustion process will pass through the smoke channel 5 and enter the air intake pipe 4 at the return air hole 42.

[0107] In addition, the combustion nozzle 7 is arranged corresponding to the air inlet hole 41, and the combustion nozzle 7 continuously sprays high-pressure and high-kinetic energy fuel gas into the air inlet hole 41. On the one hand, under the action of the combustion nozzle 7, the air in the shell 1 can also flow into the air inlet pipe 4 under the action of negative pressure. The fuel gas will drive the flue gas and fuel gas at the return air hole 42 into the air inlet pipe 4, thereby reducing the oxygen content in the air inlet pipe 4. On the other hand, an airflow can be formed from the air inlet hole 41 to the combustion plate 3, driving the flue gas entering the air inlet pipe 4 from the return air hole 42 to move toward the combustion plate 3 to form an internal circulation.

[0108] Furthermore, a plurality of return holes 42 are provided on the side wall of the intake pipe 4 near the intake hole 41, allowing smoke generated in the combustion chamber to flow into the intake pipe 4 through the return holes 42. A smoke channel 5 is formed between the fire grate body 2 and the shell 1, allowing smoke generated during the combustion process to pass through the smoke channel 5 and enter the intake pipe 4 at the return holes 42.

[0109] Among them, the return air hole 42 is obliquely opened on the side wall of the air inlet pipe 4, and the position of the return air hole 42 at one end of the outer wall of the air inlet pipe 4 is lower than the position of the end at the inner wall of the air inlet pipe 4, that is, the return air hole 42 is inclined upward from the outside of the air inlet pipe 4 to the inside, so that after the flue gas enters the inside of the air inlet pipe 4 through the return air hole 42, the flue gas itself will also move toward the end away from the air inlet hole 41, and will not move against the airflow formed by the fuel gas and the combustion-supporting gas.

[0110] Example 5

[0111] A burner assembly provided by one embodiment of the present invention includes a shell 1, a fire row piece in any of the above embodiments, and a combustion nozzle 7. A combustion chamber 13 is provided in the shell 1, and the combustion chamber 13 is a space where the fuel gas and the combustion-supporting gas burn. One fire row piece is provided and is detachably connected to the inside of the shell 1. The other end of the air intake pipe 4 in the fire row piece is connected to the combustion chamber 13, and the combustible gas enters the air intake pipe 4 through the air intake hole 41, and then flows to the combustion chamber 13 along the extension direction of the air intake pipe 4. After ignition by the ignition part, the fuel gas and the combustion-supporting gas burn. A smoke channel 5 is formed between the fire row piece and the shell 1, that is, the smoke formed during the combustion process will pass through the smoke channel 5 and enter the air intake pipe 4 at the return air hole 42.

[0112] In addition, the combustion nozzle 7 is arranged corresponding to the air inlet hole 41, and the combustion nozzle 7 continuously sprays high-pressure and high-kinetic energy fuel gas into the air inlet hole 41. On the one hand, under the action of the combustion nozzle 7, the air in the shell 1 can also flow into the air inlet pipe 4 under the action of negative pressure. The fuel gas will drive the flue gas and fuel gas at the return air hole 42 into the air inlet pipe 4, thereby reducing the oxygen content in the air inlet pipe 4. On the other hand, an airflow can be formed from the air inlet hole 41 to the combustion plate 3, driving the flue gas entering the air inlet pipe 4 from the return air hole 42 to move toward the combustion plate 3 to form an internal circulation.

[0113] Furthermore, a plurality of return holes 42 are provided on the side wall of the intake pipe 4 near the intake hole 41, allowing smoke generated in the combustion chamber to flow into the intake pipe 4 through the return holes 42. A smoke channel 5 is formed between the fire grate body 2 and the shell 1, allowing smoke generated during the combustion process to pass through the smoke channel 5 and enter the intake pipe 4 at the return holes 42.

[0114] Among them, such as Figure 9 and Figure 10 As shown, the return air hole 42 extends to the end face of the air inlet hole 41 to form a return air notch 49, which increases the channel for the flue gas to enter the air inlet pipe 4, so that the flue gas generated during the combustion process can more easily enter the air inlet pipe 4 to form an internal circulation, so that the mixed gas in the air inlet pipe 4 can be maintained in a low-oxygen environment.

[0115] Example 6

[0116] A burner assembly provided by one embodiment of the present invention includes a shell 1, a fire row piece in any of the above embodiments, and a combustion nozzle 7. A combustion chamber 13 is provided in the shell 1, and the combustion chamber 13 is a space where the fuel gas and the combustion-supporting gas burn. One fire row piece is provided and is detachably connected to the inside of the shell 1. The other end of the air intake pipe 4 in the fire row piece is connected to the combustion chamber 13, and the combustible gas enters the air intake pipe 4 through the air intake hole 41, and then flows to the combustion chamber 13 along the extension direction of the air intake pipe 4. After ignition by the ignition part, the fuel gas and the combustion-supporting gas burn. A smoke channel 5 is formed between the fire row piece and the shell 1, that is, the smoke formed during the combustion process will pass through the smoke channel 5 and enter the air intake pipe 4 at the return air hole 42.

[0117] In addition, the combustion nozzle 7 is arranged corresponding to the air inlet hole 41, and the combustion nozzle 7 continuously sprays high-pressure and high-kinetic energy fuel gas into the air inlet hole 41. On the one hand, under the action of the combustion nozzle 7, the air in the shell 1 can also flow into the air inlet pipe 4 under the action of negative pressure. The fuel gas will drive the flue gas and fuel gas at the return air hole 42 into the air inlet pipe 4, thereby reducing the oxygen content in the air inlet pipe 4. On the other hand, an airflow can be formed from the air inlet hole 41 to the combustion plate 3, driving the flue gas entering the air inlet pipe 4 from the return air hole 42 to move toward the combustion plate 3 to form an internal circulation.

[0118] Furthermore, a plurality of return holes 42 are provided on the side wall of the intake pipe 4 near the intake hole 41, allowing smoke generated in the combustion chamber to flow into the intake pipe 4 through the return holes 42. A smoke channel 5 is formed between the fire grate body 2 and the shell 1, allowing smoke generated during the combustion process to pass through the smoke channel 5 and enter the intake pipe 4 at the return holes 42.

[0119] like Figure 7 and Figure 8 As shown, a guide plate 48 is provided on the outer wall of the intake pipe 4. The guide plate 48 is annular and truncated in a cone shape, that is, the guide plate 48 is sleeved on the outer wall of the intake pipe 4. The small end of the truncated cone-shaped guide plate 48 is located above the large end, and the small end is arranged corresponding to the return air hole 42. Before the smoke generated by combustion flows back into the intake pipe 4 through the return air hole 42, the guide plate 48 first converges the smoke. The guide plate 48 then guides the smoke along the inner wall of the guide plate 48 from bottom to top, through the return air hole 42, and into the interior of the intake pipe 4, forming an internal recirculation.

[0120] Example 7

[0121] like Figure 1 、 Figure 2 、 Figure 7 and Figure 9 As shown, the air intake pipe 4 includes an air intake portion 43, an expansion portion 44, and an expansion section 46. The end of the air intake portion 43 away from the combustion plate 3 is connected to the air intake hole 41, and the other end of the air intake portion 43 is connected to the expansion portion 44. The direction from the air intake portion 43 to the expansion portion 44 is perpendicular to the combustion plane.

[0122] Furthermore, the intake pipe includes an intake portion and an expansion portion connected to each other, and the intake hole is located at an end of the intake portion away from the combustion plate. The diameter of the expansion portion can be larger than the diameter of the intake portion, that is, the cross-sectional area of ​​the expansion portion relative to the normal plane of the intake pipe axis is larger than the cross-sectional area of ​​the intake portion. Under the condition that the gas flow rate remains unchanged, according to the formula that the flow rate is equal to the flow rate divided by the area, the flow rate of the gas after entering the expansion portion will be lower than the flow rate in the intake portion. The lower flow rate not only helps the gas to diffuse evenly onto the combustion plate, but also improves the mixing efficiency between air and fuel gas, so that the mixed gas can be maintained in a low-oxygen environment. By controlling the temperature and increasing the amount of carbon monoxide, the generation of thermal nitrogen oxides is suppressed, thereby achieving low nitrogen emissions.

[0123] Furthermore, the expanded section 46 is provided in one section and is disposed at an end of the air inlet portion 43 away from the expansion portion 44. Specifically, the cross-sectional area of ​​at least a portion of the expanded section 46 is larger than the cross-sectional area of ​​the air inlet portion 43, and the diameter of at least a portion of the expanded section 46 gradually decreases from the air inlet portion 43 toward the expansion portion 44.

[0124] When the gas flow rate remains unchanged, according to the formula that flow rate is equal to flow rate divided by area, the flow velocity of the gas after entering the expansion section 46 will be lower than the flow velocity in the air intake section 43. The reduced flow velocity helps the gas to be more fully mixed while diffusing, so that the mixed gas can be maintained in a low-oxygen environment. By controlling the temperature and increasing the amount of carbon monoxide, the generation of thermal nitrogen oxides is suppressed, thereby achieving low nitrogen emissions.

[0125] In another embodiment, the number of the expanded pipe sections 46 is two.

[0126] In another embodiment, the number of the expanded pipe section 46 is multiple.

[0127] In another embodiment, the direction from the air intake portion 43 to the expansion portion 44 is not perpendicular to the plane of the combustion plate 3, that is, the air intake pipe 4 is bent and extended, increasing the length of the pipe, so that the fuel gas, combustion-supporting gas and flue gas can be better mixed, so that the mixed gas is in a low-oxygen environment.

[0128] Example 8

[0129] like Figure 1 、 Figure 2 、 Figure 7 and Figure 9 As shown, a diverter 45 is provided within the expansion portion 44. The diverter 45 has a triangular cross-section parallel to the axis of the air inlet 41, with the base of the triangle close to the combustion plate 3. As a result, when the gas flows toward the diverter 45, it flows along the sidewalls of the diverter 45, and the gas diffusion range is expanded after passing through the diverter 45. By providing the diverter 45, the flow path of the gas from the air inlet 43 to the expansion portion 44 is changed, thereby expanding the range of the flame formed.

[0130] In another embodiment, two expansion portions 44 are provided, and the diameter of each expansion portion 44 is larger than the diameter of the air inlet portion 43 .

[0131] In another embodiment, a plurality of expansion portions 44 are provided.

[0132] In another embodiment, Figure 1 As shown, the cross section of the diverter portion 45 parallel to the axis of the air inlet hole 41 is V-shaped, with the tip facing the air inlet hole 41 .

[0133] Example 9

[0134] like Figure 4 、 Figure 5 、 Figure 6 、 Figure 8 and Figure 10 As shown, a guide platform 47 is further provided in the air inlet portion 43 , and the guide platform 47 is provided at a position of the air inlet portion 43 close to the air inlet hole 41 , and the diameter of the guide platform 47 gradually decreases along the direction from the air inlet portion 43 to the expansion portion 44 .

[0135] Specifically, the combustion nozzle 7 continuously sprays gas toward the air inlet 41. After the gas passes through the air inlet 41, the flow velocity is inversely proportional to the cross-sectional area when the gas flow rate remains constant. As a result, the diameter of the guide platform 47 continuously decreases, which increases the flow velocity of the gas passing through the guide platform 47. As the gas flows through the guide platform 47, the guide platform 47 not only converges the gas but also accelerates the flow velocity, meaning that the gas quickly flows through the guide platform 47 and enters the air inlet 43. This prevents the gas from flowing out of the air inlet 41 through the return hole 42 to a certain extent, preventing the smoke from entering the air inlet 41.

[0136] Example 10

[0137] like Figure 11 As shown, a plurality of combustion hole groups 6 are provided on the side of the combustion plate 3 away from the fire bar body 2. Each combustion hole group 6 includes a plurality of combustion fire holes 61. The combustion fire holes 61 are rectangular in shape. Each fire bar body 2 is provided corresponding to at least one combustion hole group 6.

[0138] Example 11

[0139] like Figure 1 、 Figure 2 、 Figure 7 and Figure 9 As shown, the burner is a T-type burner, which has a simple structure, low cost, is easy to manufacture, and can meet the needs of large-area flames.

[0140] Example 12

[0141] like Figure 12 As shown, this embodiment provides a water heating device, comprising a shell assembly 8, a water tank 9, and the burner of any of the above embodiments, wherein the burner and the water tank 9 are both arranged inside the shell assembly 8. The burner is arranged below the water tank 9, and the water tank 9 is heated by the burner and then supplied to the user.

[0142] In another embodiment, the water tank 9 is disposed below or at the side of the burner.

[0143] In addition, the water heater may include a heat exchanger, which is located within the combustion chamber of the gas heating assembly. The heat exchanger has a water inlet and a water outlet at each end. Water enters the heat exchanger through the water inlet, exchanges heat with the high-temperature flue gas in the combustion chamber, and then flows out of the water outlet to provide hot water for the user.

[0144] Example 13

[0145] like Figures 13 to 15 As shown, this embodiment provides a gas heating device for hot water, including a shell assembly 8 and a burner and a fan 12 arranged in the shell assembly 8, and the burner includes a shell 1, a fire grate body 2, a combustion plate 3 and an air inlet pipe 4. Among them, a combustion chamber is provided in the shell 1, and the combustion chamber is a space for gas mixing and combustion. The fire grate body 2 is provided with a, and is detachably connected to the inside of the shell 1, and the combustion plate 3 is arranged on the top of the shell 1, that is, the combustion plate 3 is above the fire grate body 2. In addition, the air inlet pipe 4 is arranged in the inside of the fire grate body 2, and an air inlet hole 41 for receiving gas is formed at one end of the air inlet pipe 4 away from the combustion plate 3, and the other end of the air inlet pipe 4 is connected to the combustion chamber, that is, the air inlet hole 41 and the combustion plate 3 are on opposite sides of the fire grate body 2.

[0146] Furthermore, a plurality of return holes 42 are provided on the side wall of the intake pipe 4 near the intake hole 41, allowing smoke generated in the combustion chamber to flow into the intake pipe 4 through the return holes 42. A smoke channel 5 is formed between the fire grate body 2 and the shell 1, allowing smoke generated during the combustion process to pass through the smoke channel 5 and enter the intake pipe 4 at the return holes 42.

[0147] When the burner burns in the combustion chamber, it produces a certain amount of flue gas. This flue gas then enters the intake pipe 4 through the air return hole 42 and mixes with the fuel gas and air in the intake pipe 4. Since the flue gas produced by combustion has a very low oxygen content, it will reduce the oxygen content of the gas in the intake pipe 4 after entering the intake pipe 4, reducing the degree of combustion efficiency during the burner combustion, thereby lowering the burner flame temperature.

[0148] Since the flame temperature of the burner is reduced, the nitrogen oxides (NO X ), thereby reducing the emission of nitrogen oxides from the gas heating components to reduce the pollution of nitrogen oxides to the environment.

[0149] Since the nitrogen oxides produced by the burner combustion are reduced, the harm of nitrogen oxides to the human body is reduced, making it safer and more reliable for users to use the gas heating components, thereby improving the safety of the use of gas heating components.

[0150] The air return holes 42 provided on the fire bar body 2 enable internal circulation of flue gas within the gas heating assembly without the need for additional structural components, thereby reducing nitrogen oxide emissions, simplifying the structure of the gas heating assembly, and lowering the cost of the gas heating assembly. Furthermore, since no additional structural components are required, the volume of the gas heating assembly is reduced, reducing the space occupied by the gas heating assembly.

[0151] Specifically, over 90% of the nitrogen oxides produced by burners are thermal nitrogen oxides, formed at high temperatures. Temperature and air are the primary factors influencing thermal nitrogen oxides, and their relationship is approximately linear. Therefore, adding flue gas to the intake duct reduces the oxygen concentration of the combustible mixture. Low-oxygen combustion reduces the heat release rate, eliminating the instantaneous, high-temperature heat release in small volumes seen in traditional combustion, thereby suppressing the formation of thermal nitrogen oxides.

[0152] Before the flue gas is mixed into the intake pipe 4, the concentration of nitrogen oxides generated by the burner after combustion is between 80ppm (parts per million) and 100ppm. After the flue gas is introduced into the intake pipe 4, the emission of nitrogen oxides is below 36mg / kWh (milligrams per kilowatt-hour), meeting the European standard of nitrogen oxide emissions less than or equal to 56mg / kWh and the national standard of nitrogen oxide emissions less than or equal to 70ppm.

[0153] After the flue gas is mixed into the air inlet pipe 4, the flame temperature is controlled between 1350 degrees and 1500 degrees. Experimental verification shows that when the flame temperature is less than 1350 degrees, the amount of carbon monoxide produced by the burner combustion increases sharply. When the flame temperature is greater than 1500 degrees, the amount of nitrogen oxides produced by the burner combustion may also increase sharply. Therefore, controlling the flame temperature of the burner between 1350 degrees and 1500 degrees can prevent the burner from producing a large amount of nitrogen oxides and a large amount of carbon monoxide.

[0154] In addition, there will be a certain amount of carbon monoxide in the flue gas. Due to the setting of the return air hole 42, the flue gas carrying carbon monoxide can be discharged back into the intake pipe 4, so that the carbon monoxide can be burned to form carbon dioxide when it burns again, reducing the emission of carbon monoxide and reducing safety hazards.

[0155] Example 14

[0156] like Figure 13 and Figure 14As shown, this embodiment provides a gas heating device for hot water, including a shell assembly 8 and a burner and a fan 12 arranged in the shell assembly 8, and the burner includes a shell 1, a fire grate body 2, a combustion plate 3 and an air inlet pipe 4. Among them, a combustion chamber is provided in the shell 1, and the combustion chamber is a space for gas mixing and combustion. The fire grate body 2 is provided with a, and is detachably connected to the inside of the shell 1, and the combustion plate 3 is arranged on the top of the shell 1, that is, the combustion plate 3 is above the fire grate body 2. In addition, the air inlet pipe 4 is arranged in the inside of the fire grate body 2, and an air inlet hole 41 for receiving gas is formed at one end of the air inlet pipe 4 away from the combustion plate 3, and the other end of the air inlet pipe 4 is connected to the combustion chamber, that is, the air inlet hole 41 and the combustion plate 3 are on opposite sides of the fire grate body 2.

[0157] Furthermore, a plurality of return holes 42 are provided on the side wall of the intake pipe 4 near the intake hole 41, allowing smoke generated in the combustion chamber to flow into the intake pipe 4 through the return holes 42. A smoke channel 5 is formed between the fire grate body 2 and the shell 1, allowing smoke generated during the combustion process to pass through the smoke channel 5 and enter the intake pipe 4 at the return holes 42.

[0158] Furthermore, the bottom wall of the housing 1 and the partition 81 enclose an air inlet passage 82, into which the fan 12 delivers air, thereby improving the combustion efficiency of the burner. While maintaining the same heating efficiency, the burner volume can be effectively reduced, thereby reducing the space occupied by the gas heating component.

[0159] In a specific embodiment, Figure 15 As shown, an exhaust port is provided at the top of the shell 1, an exhaust pipe 11 is installed at the exhaust port, and a heat exchanger is provided between the burner and the exhaust port, so that part of the flue gas generated by the burner flows back to the return air hole 42, and the other part is discharged from the water heater after heat exchange with the heat exchanger.

[0160] The return air pipe 10 is mounted outside the exhaust pipe 11, and the exhaust pipe 11 is located inside the return air pipe 10, thereby reducing the space occupied by the water heater. The space inside the exhaust pipe 11 is used to discharge the exhaust gas generated by the burner; the gap between the return air pipe 10 and the exhaust pipe 11 is used to introduce air from the outside or the flue.

[0161] In a specific embodiment, Figure 15 As shown, a fan 12 is provided at the exhaust pipe 11. The fan 12 blows air outward to create a negative pressure within the shell assembly 8, thereby allowing external air to flow into the burner through the intake pipe 4. According to embodiments of the burner and water heater of the present invention, by providing a return air hole in the intake pipe near the air inlet hole, the return flue gas is used to create a low-oxygen environment in the intake pipe, thereby suppressing the generation of thermal nitrogen oxides to a certain extent and thereby achieving low nitrogen emissions.

[0162] In summary, through the embodiments of the present invention, by opening a return air hole near the air inlet hole in the air intake pipe and using the returned flue gas to place the air intake pipe in a low-oxygen environment, the generation of thermal nitrogen oxides can be suppressed to a certain extent, thereby achieving low nitrogen emissions.

[0163] In the present invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "plurality" refers to two or more, unless expressly limited otherwise. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a detachable connection, or an integral connection; "connected" can mean a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0164] In the description of the present invention, it should be understood that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0165] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0166] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A fire row film, characterized in that: include: A fire grate body, wherein a combustion plate is provided on the fire grate body; An air inlet pipe is provided in the fire grate body, and one end of the air inlet pipe forms an air inlet hole for receiving the gas, and the other end is connected to the combustion chamber through the combustion plate, and the air inlet hole and the combustion plate are provided on opposite sides of the fire grate body. A return air hole is provided on a side wall of the intake pipe at one end thereof close to the intake hole, and passes through the side wall. The smoke generated in the combustion chamber can flow into the intake pipe through the return air hole. The return air hole is a tapered hole, and the diameter of the tapered hole decreases from the outside of the intake pipe to the inside of the intake pipe. The fire row piece also includes: A guide plate, one end of which is arranged corresponding to the return air hole, and the other end of which is bent outward and extends radially along the intake pipe. The guide plate is sleeved on the outer wall of the intake pipe. Before the smoke generated by combustion flows back to the intake pipe through the return air hole, the guide plate will first converge the smoke.

2. The fire strip according to claim 1, characterized in that: The air intake pipe comprises: An air inlet portion, wherein the air inlet hole is formed at one end of the air inlet portion away from the combustion plate; an expansion portion connected to the air inlet portion, The fuel gas flows from the intake portion into the intake pipe and flows through the expansion portion into the combustion chamber.

3. The fire row sheet according to claim 2, characterized in that: Also includes: The diverter is provided in the expansion portion, and the diverter can separate the flow path of the gas flowing from the air inlet portion to the expansion portion.

4. The fire strip according to claim 2, characterized in that: The direction from the air inlet portion to the expansion portion is perpendicular to the plane where the combustion plate is located.

5. The fire strip according to claim 2, characterized in that: An expansion section is provided at one end of the air inlet portion away from the expansion portion, and a cross-sectional area of ​​at least a portion of the expansion section is larger than a cross-sectional area of ​​the air inlet portion.

6. The fire strip according to claim 5, characterized in that: The diameter of at least part of the expanded pipe section gradually decreases in a direction from the air inlet portion to the expansion portion.

7. The fire strip according to claim 2, characterized in that: The air intake pipe further comprises: The guide platform is arranged in the air inlet portion and is close to the air inlet hole. Wherein, the pipe diameter of the guide platform gradually decreases along the direction from the air inlet portion to the expansion portion.

8. The fire strip according to any one of claims 1 to 7, characterized in that: The air return hole extends to the end surface of the air inlet hole to form an air return gap.

9. The fire strip according to any one of claims 1 to 7, characterized in that: There are multiple air return holes.

10. The fire strip according to any one of claims 1 to 7, characterized in that: The combustion plate is arranged on the top of the fire grate body, and a combustion hole group is provided on a side of the combustion plate away from the air inlet pipe.

11. The fire strip according to claim 10, characterized in that: The combustion hole group includes at least one combustion fire hole, and the combustion fire hole is rectangular in shape.

12. A burner assembly, characterized in that: include: a housing, wherein a combustion chamber is provided in the housing; A plurality of fire strips according to any one of claims 1 to 11, wherein the other end of the air inlet pipe of the fire strip is connected to the combustion chamber through the combustion plate; The combustion nozzle is arranged corresponding to the air inlet hole of the fire row piece, and the combustion nozzle can spray gas into the air inlet hole.

13. The burner assembly according to claim 12, wherein: A smoke channel is formed between the fire row piece and the shell; and / or A smoke channel is formed between any two adjacent fire row slices among the plurality of fire row slices.

14. A water heating device, characterized in that: include: Shell assembly, wherein the shell assembly is provided with a water tank ； The burner assembly according to claim 12 or 13 is arranged in the shell assembly corresponding to the water tank.

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