CN117824144A

CN117824144A - Gas water heater and combustion device, thick and thin fire grate thereof

Info

Publication number: CN117824144A
Application number: CN202410142252.1A
Authority: CN
Inventors: 邱步; 段毅; 李智
Original assignee: AO Smith China Water Heater Co Ltd
Current assignee: AO Smith China Water Heater Co Ltd
Priority date: 2018-11-23
Filing date: 2018-11-23
Publication date: 2024-04-05
Also published as: CN109489240B; CN109489240A

Abstract

The application discloses gas water heater and burner, thick and thin fire row thereof relates to hot water equipment field, thick and thin fire row includes: the thick and thin fire row comprises a mixing cavity and a combustion port; the thick fire row and the thin fire row are provided with a first air inlet and a second air inlet; the combustion port comprises a rich side combustion port communicated with the first air inlet and a lean side combustion port communicated with the second air inlet; the concentration of the fuel gas in the gas input by the first gas inlet is greater than that in the gas input by the second gas inlet; the thick side combustion port is positioned at two sides of the thin side combustion port along the length direction perpendicular to the thick and thin fire row. The application can reduce the content of nitrogen oxides in the flue gas exhausted by the gas water heating device.

Description

Gas water heater and combustion device, thick and thin fire grate thereof

The application is a divisional application with the application number of 201811406745.2, the application date of 2018, 11, 23 days and the name of gas water heater.

Technical Field

The application relates to the field of hot water equipment, in particular to a gas hot water device, a combustion device and a thick and thin fire grate thereof.

Background

The gas water heater uses gas as fuel, and transfers heat to cold water flowing through the heat exchanger in a combustion heating mode, so that the purpose of preparing hot water is achieved. The gas water heating device burns gas to form smoke in the working process, and finally the smoke is discharged to the outdoor through the smoke pipe.

Because the flue gas discharged by the gas water heating device has a certain amount of nitrogen oxides, certain pollution is formed to the surrounding environment, and corresponding discharge standards are provided for the gas water heating device in different countries. With the increasing demands of the public on environmental quality, the smoke emission of the current gas water heating device is also put higher demands.

The burner of the existing gas water heater is provided with a plurality of fire rows which are arranged side by side, and a certain amount of gas and air are simultaneously input into the fire rows for premixing. In order to burn completely, an air inlet gap is also arranged between the fire bars, and air is input through the air inlet gap. The air input by the air inlet gap is used for participating in combustion on the combustion surface of the fire grate, so that the aim of complete combustion is fulfilled. However, the flue gas discharged by the gas water heating device with the structure contains higher nitrogen oxides, and environmental quality is easily affected.

Disclosure of Invention

For reducing the content of nitrogen oxides in the flue gas discharged by the gas water heating device, the application provides the following technical scheme:

a light and dark fire row having a first air inlet and a second air inlet; the combustion port comprises a rich side combustion port communicated with the first air inlet and a lean side combustion port communicated with the second air inlet; the concentration of the fuel gas in the gas input by the first gas inlet is greater than that in the gas input by the second gas inlet; the thick side combustion port is positioned at two sides of the thin side combustion port along the length direction perpendicular to the thick and thin fire row.

In a preferred embodiment, the size of the light-side combustion port is 10 square millimeters or less.

As a preferred embodiment, the size of the light side combustion port is 3-8 square millimeters.

As a preferred embodiment, 3-20 light side combustion ports are uniformly distributed in unit square centimeter.

As a preferred embodiment, the light-side combustion port is a honeycomb structure or a honeycomb-like structure.

As a preferred embodiment, the light and shade fire row comprises a core assembly and a shell; the inner core assembly extends along the length direction of the thick and thin fire row; a long-strip-shaped thick-side combustion port is formed between the shell and the inner core assembly; the light side burner port is formed on the inner core assembly.

As a preferred embodiment, the core assembly is formed by press bending or press welding.

As a preferred embodiment, the inner core assembly comprises a plurality of stamping plates, and the stamping grooves of two adjacent stamping plates are aligned to form the light side combustion port.

As a preferred embodiment, the plurality of stamping plates are single stamping plate bodies which are bent to form the inner core assembly, or the two ends of the plurality of stamping plates are fixed together by welding to form the inner core assembly.

As a preferred embodiment, the first air inlet and the second air inlet are arranged up and down.

As a preferred embodiment, the first air inlet is located below the second air inlet, the area of the second air inlet is smaller than that of the first air inlet, and the amount of fuel gas input by the second air inlet is smaller than that input by the first air inlet.

As a preferred embodiment, a plurality of the light-side combustion ports are disposed in close proximity and evenly distributed.

In a preferred embodiment, the plurality of light-side combustion ports form a plurality of rows, the light-side combustion ports in each row being arranged in the longitudinal direction of the thick and light fire row, and the light-side combustion ports in two adjacent rows being offset.

The combustion device comprises a frame body and a plurality of thick and thin fire rows arranged in the frame body.

As a preferred embodiment, more than 85% of the air entering the combustion device enters a plurality of the light-shade fire rows.

As a preferred embodiment, all air entering the combustion device enters the light-shade fire row; the combustion device is configured such that air cannot enter the combustion space from outside the light-shade fire row.

As a preferred embodiment, a baffle is provided in the frame; the baffle is arranged at the upstream of the thick fire row and the thin fire row; the baffle plate is arranged so that all air entering the combustion device enters the thick and thin fire row, and air cannot enter the combustion space from the outside of the thick and thin fire row.

As a preferred embodiment, the combustion device is provided with a spacing structure that separates a combustion space from an intake space upstream of the combustion space; the interval structure is provided with a communication part for communicating the combustion space with the air inlet space; part of air in the air inlet space can enter the thick and thin fire row, and part of air can enter the combustion space from the outside of the thick and thin fire row through the communication part; the area ratio of the communicating portion to the spacing structure is less than 5%.

As a preferred embodiment, the area ratio of the projection of the communication portion to the partition structure on the horizontal plane is less than 5%.

As a preferred embodiment, the air input by the communicating portion enters the gap between two adjacent thick and thin fire rows, and the area ratio of the communicating portion to the spacing structure is less than 1%.

As a preferred embodiment, the spacing structure includes a baffle plate disposed in the frame; the baffle is arranged at the upstream of the thick fire row and the thin fire row.

As a preferred embodiment, the communicating portion includes an air inlet provided to the baffle plate; the opening rate of the air inlet hole on the baffle plate is below 3%.

As a preferred embodiment, a plurality of the light-shade fire rows and gaps between the light-shade fire rows form a burner; the burner is not provided with the communication part in the projection area of the baffle plate along the vertical direction.

As a preferred embodiment, a plurality of the light-shade fire rows and gaps between the light-shade fire rows form a burner; the communication part is arranged in an area of the burner outside the projection area of the baffle plate along the vertical direction.

As a preferred embodiment, the baffle is a rectangular plate; the air inlet is arranged close to the side edge of the baffle plate.

A gas water heating apparatus comprising: the combustion apparatus of any one of the above.

As a preferred embodiment, the gas water heating device further comprises a heat exchanger and a fan, and the combustion device, the heat exchanger and the fan are arranged in sequence.

As a preferred embodiment, the gas water heating device is provided with a gas supply device for inputting gas into the thick and thin fire bars, and air and the gas provided by the gas supply device enter a fire bar mixing cavity through a first gas inlet and a second gas inlet of the thick and thin fire bars, and are mixed in the mixing cavity and then burnt at the combustion port to form a combustion surface.

In a preferred embodiment, the area ratio of the combustion ports to the combustion surface of the plurality of the light-shade fire rows is greater than 90%.

In a preferred embodiment, a combustion space is provided between the multiple thick and thin fire rows and the heat exchanger, and flames formed by the multiple thick and thin fire rows through the combustion ports are mutually fused to form a complete combustion surface in the combustion space.

As a preferred embodiment, the heat exchanger is a fin type heat exchanger.

The beneficial effects are that:

when the air quantity input by the outside of the fire grate is reduced or the air entering the outside of the fire grate is thoroughly eliminated, the air mainly enters the combustion device through or only through the inlet of the fire grate, so that the airflow speed of the combustion port of the fire grate is increased, the flow speed of high-temperature flue gas generated by combustion is high, the residence time of the flue gas in a high-temperature area is short, the generation reaction of nitrogen oxides is inhibited, and the amount of the nitrogen oxides discharged by the whole gas water heating device is reduced.

In addition, simultaneously, the fan sets up in the low reaches of heat exchanger, and the negative pressure that forms in air inlet space department draws under the effect and evenly gets into in every fire row, is favorable to every fire row to burn and forms uniform flame to form the combustion face of temperature uniformity in the combustion space, reduce the nitrogen oxide content in the burning flue gas.

In addition, when the fin type heat exchanger is used, the fan is positioned at the downstream of the heat exchanger, and the fins of the fin type heat exchanger can play a good role in rectifying and equalizing pressure on the air flow formed by the suction of the fan, so that a space with uniform pressure is formed in the combustion space, a combustion surface with better uniformity and integrity is formed conveniently, the temperature of the combustion surface is distributed uniformly, a local temperature overheating area cannot be generated in the combustion space 7, and the formation of nitrogen oxides is inhibited.

Specific embodiments of the invention are disclosed in detail below with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not limited in scope thereby. The embodiments of the invention include many variations, modifications and equivalents within the spirit and scope of the appended claims.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic view of a gas water heating device according to an embodiment of the present disclosure;

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a schematic view of the combustion apparatus of FIG. 1;

FIG. 4 is a front view of FIG. 3;

FIG. 5 is a top view of the frame of FIG. 1;

FIG. 6 is a schematic view of the fire grate structure of FIG. 1;

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a top view of FIG. 6;

fig. 9 is a schematic view of the core assembly of fig. 6.

Reference numerals illustrate: 100. a housing; 1. a blower; 2. a heat exchanger; 3. a combustion device; 4. a gas supply device; 5. an air intake space; 6. a smoke exhaust pipe; 7. a combustion space; 31. a frame; 32. discharging fire; 33. a first air inlet; 34. a second air inlet; 33a/34a, openings; 35. a baffle; 36. a front side plate; 37. a rear side plate; 38. left and right side plates; 39. a housing; 40. a rich side combustion port; 41. a light side combustion port; 42. a combustion port; 43. an inner core assembly; 44. a stamping plate; 45. and a support structure.

Detailed Description

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, shall fall within the scope of the invention.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Please refer to fig. 1 to 9. Embodiments of the present application provide a gas water heating device, including but not limited to a gas water heater and a wall-mounted boiler, which is not limited to the present application. The gas water heating device comprises: the combustion device 3, the heat exchanger 2 and the fan 1 are arranged in sequence. The combustion device 3 includes a frame 31 and a plurality of fire rows 32 provided in the frame 31. The gas water heater is provided with a gas supply device 4 for supplying gas to the fire grate 32. The fire row 32 includes mixing chambers and combustion ports 42. Air and fuel gas supplied from the fuel gas supply device 4 enter the mixing chamber of the fire row 32 through air inlets (such as a first air inlet 33 and a second air inlet 34 described below) of the fire row 32, and are mixed in the mixing chamber and then burnt at the combustion port 42 to form a combustion surface.

In the embodiment of the present application, the fan 1, the heat exchanger 2, and the combustion device 3 are installed in the housing 100 of the gas water heating device. The fan 1 can be a variable frequency fan to provide wind conditions under different powers so as to adapt to different firepower. The heat exchanger 2 may preferably be a fin type heat exchanger. Among them, the fin type heat exchanger has a better pressure equalizing effect so as to form uniform pressure in the combustion space. The downstream of the fan 1 is communicated with a smoke exhaust pipe 6, and the fan 1 finally discharges the sucked smoke outwards through the smoke exhaust pipe 6. The gas supply device 4 may be a distributor. The gas outlet of the distributor corresponds to the inlet of the fire row 32.

Between the plurality of fire rows 32 and the heat exchanger 2 there is a combustion space 7, which combustion space 7 may also be referred to as a combustion chamber. As shown in fig. 1 to 4, the frame 31 may include a wall plate surrounding the combustion space 7. The combustion space 7 is a rectangular space (rectangular in cross section). The fire grate 32 is capable of forming combustion in the combustion space 7 under the supplied fuel gas and air and forming high temperature flue gas. The high-temperature flue gas is sucked by the fan 1 and flows through the finned tubes of the heat exchanger 2, and exchanges heat with the heat exchanger 2 to heat cold water in the heat exchanger 2.

Below the baffle 35 there is an air intake space 5. The intake space 5 supplies air to the combustion device 3. Wherein the air intake space 5 mainly supplies air to the inside of the fire row 32 to be mixed with the fuel gas supplied from the fuel gas supply means 4. In this embodiment, the fire row 32 is a shade fire row. The same fire row 32 has a rich side combustion port 40 and a lean side combustion port 41. Wherein, the density and the light are different in concentration of fuel gas in the burnt gas. The rich side combustion port 40 is larger in the concentration of the fuel gas in the combustion gas than the lean side combustion port 41.

The combustion device 3 is provided with a spacing structure separating the combustion space 7 from the intake space 5. The spacing structure may be a baffle 35 disposed upstream of the fire row 32. As shown in fig. 4 and 5, the baffle 35 is located below the fire row 32, and the plate body is parallel to the horizontal plane. The baffle 35 is fixed in the frame 31, wherein the baffle 35 may be a part of the frame 31 or may be an additional component, and the present application is not limited thereto. Specifically, the baffle 35 may have a rectangular structure, forming a horizontally disposed rectangular plate.

In the present embodiment, the combustion space 7 has a rectangular parallelepiped structure as a whole, and the frame 31 surrounds the combustion space 7. The frame 31 includes opposite front and rear side plates 36, 37, and opposite left and right side plates 38. Of the two ends of the fire row 32 in the length direction, one end is erected on a support structure 45, and the support structure 45 is located below the front side plate 36. The support structure 45 may be integral with the baffle 35 to form a "Z" shaped plate, although this is not precluded as a separate structure. The fire row 32 is supported by a horizontal access plate (indicated by reference numeral 45), and a vertical connection plate connects the horizontal access plate with a horizontally placed baffle 35, and openings 33a, 34a provided in the vertical connection plate corresponding to air inlets (e.g., first air inlet 33, second air inlet 34) of the fire row 32 are provided.

In the embodiment of the application, the fan 1 is arranged at the downstream of the heat exchanger 2, and air is injected into the fire row 32 through negative pressure to be mixed with fuel gas and enter the combustion device 3. The fan 1 is arranged at the downstream of the heat exchanger 2, the negative pressure formed at the air inlet space 5 is low (generally between minus 10 and minus 20 Pa), correspondingly, as the air flow of the fuel gas entering the fire row 32 is slow, the fuel gas and the air can be uniformly mixed as far as possible before reaching the combustion port 42 of the fire row 32 for combustion, the stability of combustion is ensured, the uniformity of a combustion surface is formed, and the nitrogen oxide content in the combustion flue gas is reduced.

Meanwhile, the fan 1 is arranged at the downstream of the heat exchanger 2, and the air quantity entering each fire row under the negative pressure injection effect formed at the air inlet space 5 is the same, so that each fire row is combusted to form uniform flame, a combustion surface with uniform temperature is formed in the combustion space, and the nitrogen oxide content in the combustion flue gas is reduced.

The combustion device 3, the heat exchanger 2 and the fan 1 can be arranged in sequence along the flow direction of the flue gas formed by the combustion device 3. Specifically, the fan 1, the heat exchanger 2 and the combustion device 3 may be sequentially arranged from top to bottom. In other embodiments, the fan 1, the heat exchanger 2, and the combustion device 3 may be sequentially disposed from bottom to top, which is not limited in this application.

The fan 1 is located the low reaches of heat exchanger 2, and the fin of heat exchanger 2 can play better rectification pressure equalizing effect to the air current that fan 1 suction formed, is favorable to forming the combustion face that homogeneity, wholeness are better, and the temperature distribution of combustion face is even to can not produce the overheated region of local temperature in combustion space 7, inhibit the formation of nitrogen oxide.

In a preferred embodiment of the present application, more than 85% of the air entering the combustion device 3 enters the plurality of fire rows 32. Air entering the fire row 32, which is mixed with the fuel gas and burned at the burner ports 42 of the fire row 32.

In this embodiment, the amount of air entering from outside the fire row 32 may be reduced to zero so that the entire amount of air enters the plurality of fire rows 32. In this embodiment, an air amount of 15% or less is introduced from outside the plurality of banks 32, or no air is introduced from outside the banks 32. The air entering the combustion device 3 outside the fire row 32 may cool the wall plate of the combustion space or may participate in combustion in a small amount, which is not limited in this application.

In this embodiment, when the air amount input from the outside of the fire grate 32 is reduced or the air entering from the outside of the fire grate 32 is completely eliminated, the air mainly enters the combustion device 3 through or only through the inlet of the fire grate 32, so that the airflow speed of the combustion ports 42 of the fire grate 32 is increased, the flow speed of high-temperature flue gas generated by combustion is high, the residence time of the flue gas in the high-temperature area is short, the generation reaction of nitrogen oxides is inhibited, and the amount of nitrogen oxides discharged by the whole gas water heating device is reduced.

The flames formed by the combustion ports 42 of the fire rows 32 are mutually fused to form a complete combustion surface in the combustion space 7, so that the combustion uniformity is good, the content of nitrogen oxides generated in the combustion process is reduced, the generation probability of combustion resonance can be reduced, the combustion noise is reduced, and the user experience is improved. Wherein the area ratio of the combustion ports 42 of the plurality of fire rows 32 to the combustion surface is greater than 90%.

In a preferred embodiment, to reduce the nitrogen oxide content of the exhaust flue gas, a combustion surface is formed with a uniform temperature, and at least a part of the combustion openings are smaller than 10 square millimeters. In this embodiment, the fire row 32 is a thick and thin fire row, and in this embodiment, the thin side combustion ports 41 and the thick side combustion ports 40 are simultaneously present on the single fire row 32 of the thick and thin fire row 32.

On the fire row 32, 3-20 light side combustion ports 41 are uniformly provided per square centimeter. Since the light-side combustion ports 41 are uniformly distributed, it is possible to distribute the mixed gas (mixed gas of fuel gas and air) input from the second air intake port 34 into each of the light-side combustion ports 41. Therefore, the combustion surface (a part of the entire combustion surface) formed at the light-side combustion port 41 can be regarded as being formed by a uniform small flame, and the combustion temperature of the combustion surface is more uniform, so that the amount of nitrogen oxides generated during combustion is reduced.

In this embodiment, the light side combustion ports 41 may be circular holes, polygonal holes, or irregular holes, and in this embodiment, the light side combustion ports 41 are regular hexagonal holes, and a plurality of light side combustion ports 41 are arranged to form a honeycomb structure. The honeycomb-like structure is formed when the light-side combustion ports 41 are arranged in a honeycomb-like topological structure (as shown in fig. 9) when they are circular holes, quasi-circular holes, triangular holes, elliptical holes, square holes, rectangular holes, pentagonal holes, trapezoidal holes, or other polygonal holes.

The plurality of light-side combustion ports 41 are disposed in close proximity and evenly distributed. The light side combustion ports 41 are arranged in a plurality of rows, the light side combustion ports 41 in each row are arranged along the length direction of the fire row 32, and the light side combustion ports 41 in two adjacent rows can be staggered.

The light and shade fire row 32 has a first air inlet 33 and a second air inlet 34. The combustion ports 42 include a rich side combustion port 40 communicating with the first intake port 33, and a lean side combustion port 41 communicating with the second intake port 34. The concentration of the fuel gas in the gas input from the first gas inlet 33 is greater than the concentration of the fuel gas in the gas input from the second gas inlet 34. The rich side combustion ports 40 are located on both sides of the lean side combustion ports 41 in a direction perpendicular to the length direction of the rich and lean fire row 32.

The first air inlet 33 and the second air inlet 34 are arranged up and down. In the present embodiment, the first air inlet 33 is located below the second air inlet 34, the area of the second air inlet 34 is smaller than the area of the first air inlet 33, and the amount of fuel gas input to the second air inlet 34 is smaller than the amount of fuel gas input to the first air inlet 33.

At least a portion of the number of the combustion ports 42 are of a honeycomb or honeycomb-like structure. The honeycomb-like structure of the combustion ports 42 is uniformly distributed to facilitate uniform distribution of the inlet gas to the fire grate 32 and thus to facilitate formation of a combustion surface of uniform temperature. In the present embodiment, the light-side combustion port 41 has a honeycomb structure. Correspondingly, the combustion ports 42 of the honeycomb structure are uniformly distributed, and the cross section of each combustion port 42 is of a regular hexagonal structure or a circular-like structure. The light side combustion port 41 is honeycomb or honeycomb-like.

In this embodiment, the light and shade fire row 32 includes a core assembly 43 and a shell 39. The core assembly 43 extends along the length of the array of light and shade fires 32. The housing 39 is sandwiched on both sides of the core assembly 43. An elongated rich side burner 40 is formed between the shell 39 and the core assembly 43.

The light side burner 41 is formed on the inner core assembly 43. The inner core assembly 43 is provided with a plurality of light side combustion ports 41, specifically, the size of the light side combustion ports 41 is 3-8 square millimeters, so that a stable and complete combustion surface can be provided, the temperature of the combustion surface is uniform, and the content of nitrogen oxides in the formed flue gas is low. Further, the size of the light side combustion port 41 is 6-8 mm square, and the effect of suppressing the formation of nitrogen oxides is improved.

The core assembly 43 is formed by press bending or press welding. Wherein the core assembly 43 may include a plurality of stamping plates 44. The punched grooves of adjacent two punch plates 44 are aligned to form the light side burner 41. The plurality of stamping plates 44 may be formed by bending a single stamping plate body, or two ends of the plurality of stamping plates 44 may be fixed together by welding to form the core assembly 43.

In other embodiments of the present application, the light-shade fire row 32 may have various embodiments, and is not limited to the above-described structure, for example: the thick and thin fire rows 32 may include thick fire rows 32 and thin fire rows 32 that are alternately arranged, wherein the concentration of fuel gas in the gas burned by the thick fire rows 32 is greater than the concentration of fuel gas in the gas burned by the thin fire rows 32.

In another possible embodiment of the present application, the partition structure is provided with a communication portion that communicates the combustion space 7 and the intake space 5. The intake space 5 is located upstream of the combustion space 7. Part of the air in the intake space 5 can enter the fire row 32 and part of the air can enter the combustion space 7 from outside the fire row 32 through the communication portion. Specifically, under the drive of the blower fan 1, part of the air that enters the intake space 5 enters the combustion space 7 from outside the fire row 32 through the communication portion, and part of the air enters the fire row 32.

The spacing structure may be disposed between adjacent fire rows 32, upstream of the fire rows 32, or even on a side wall of the fire rows 32. The intake space 5 and the combustion space 7 may be partitioned by a partition structure such that air of the intake space 5 mainly enters the inside of the fire row 32. The communication part is arranged on the interval structure, and the air in the air inlet space 5 can enter the combustion space 7 to participate in combustion or cooling and the like without passing through the inner part of the fire row 32 through the communication part under the drive of the fan 1.

In this embodiment, the area ratio of the communicating portion to the spacing structure is less than 5%, so that the content of nitrogen oxides in the output flue gas can be reduced to a better effect. Specifically, the area ratio of the projection of the communication part and the spacing structure on the horizontal plane is less than 5%. By reducing the proportion of the communicating portions in the spacing structure, air can be made to enter the combustion apparatus 3 mainly or only through the inlet of the fire row 32, which increases the air flow speed of the combustion ports 42 of the fire row 32, the flow speed of high-temperature flue gas generated by combustion is high, the residence time of the flue gas in the high-temperature region is short, the generation reaction of nitrogen oxides is suppressed, and the amount of nitrogen oxides discharged by the whole gas water heating apparatus is reduced.

The following table shows the effect of the opening ratio on the rectangular baffle 35 on the nitrogen oxide discharge amount:

percentage of open hole (%)	NOx(3％O ₂ ，ppm)
		15	80
10	60
		5	30
2	20
		1	16

From the above table, it can be seen that the amount of nitrogen oxides in the flue gas discharged by the air inlet when the aperture ratio of the air inlet on the baffle 35 is below 5% is lower than 30ppm, the nitrogen oxides content is low, and the flue gas discharge effect is good.

Further, to better reduce the content ratio of nitrogen oxides in the discharged flue gas, the air input by the communicating portion enters the gap between two adjacent fire rows 32, and the area ratio of the communicating portion to the spacing structure is less than 1%. Thus, the air quantity entering the gaps between the fire rows 32 can be effectively restrained, the combustion effect is better, and the content of nitrogen oxides in the discharged flue gas is lower.

In this embodiment, the communicating portion includes an air inlet provided to the baffle 35. The air inlet hole communicates the upper space and the lower space of the baffle 35, and the air of the inlet air flows out through the air inlet hole under the negative pressure suction effect of the fan 1. In this embodiment, the aperture ratio of the air inlet hole in the baffle 35 is 3% or less. The baffle 35 is a rectangular plate for better nitrogen oxide suppression. The air inlet is arranged close to the side edge of the baffle 35.

In one embodiment, a plurality of the fire rows 32 and gaps between the fire rows 32 form a burner. The burner is not provided with the communication portion in the projection area of the baffle 35 in the vertical direction. So can effectively avoid the too much air that participates in the burning to the clearance input between the fire row 32, can effectively make the surplus air of light side combustion port 41 supply the oxygen that rich side combustion port 40 fuel-rich burning required in flame downstream to form stable burning classification, guarantee the stability of burning and the homogeneity of combustion face temperature, thereby can't form local overheated in combustion space 7, effectively restrain the production of nitrogen oxide, thereby reduce the content of nitrogen oxide in the flue gas that discharges.

In another embodiment, a plurality of the fire rows 32 and gaps between the fire rows 32 form a burner. The communication portion is provided in an area of the burner other than the projection area of the baffle 35 in the vertical direction. The air input in the area outside the burner may form cooling air between the fire row 32 and the wall of the combustion space 7, preventing the flame from burning towards the wall of the combustion space 7, facilitating the cooling of the wall of the combustion space 7.

Of course, the air input in the area other than the projection area is not excluded from the present embodiment to participate in combustion. Accordingly, the air input outside the fire grate 32 in this embodiment may be partially involved in combustion and partially used for cooling, which is not limited to this application.

In a preferred embodiment, all of the air entering the combustion device 3 enters the fire row 32; the combustion device 3 is configured such that air cannot enter the combustion space 7 from outside the fire row 32. Accordingly, the air in the air intake space 5 driven by the fan 1 is entirely introduced into the fire row 32 and mixed with the fuel gas in the mixing chamber.

In this embodiment, a baffle 35 is provided in the housing 31. The baffles 35 are mounted upstream of the fire row 32; the baffle 35 is arranged such that all air entering the combustion device 3 enters the fire row 32 and no air can enter the combustion space 7 from outside the fire row 32. No air inlet is arranged on the baffle 35, and correspondingly, the aperture ratio on the baffle 35 is zero.

For the rich-lean flame row 32, the rich-side combustion ports 40 are located on both sides of the lean-side combustion ports 41, and the surplus air of the lean-side combustion ports 41 downstream of the flame can supplement the oxygen required for the rich-side combustion ports 40 to output the gas rich in fuel gas for combustion, so that the combustion is staged (similar to staged combustion). However, when a large amount of air is supplied to the gap between the banks, on the one hand, the oxygen content of the combustion device 3 increases at the same rotation speed, and at the same time, too much air supplied to the gap between the banks causes the gas in the rich side combustion port 40 to burn out rapidly, which results in a temperature increase in the rich side combustion port 40 and worsens the emission of nitrogen oxides (NOx).

By reducing the amount of air input by the fire exhaust gap and even removing the air input by the fire exhaust gap, the excessive air of the light side combustion port 41 can effectively supplement the oxygen required by the fuel-rich combustion of the rich side combustion port 40 at the downstream of the flame, so that stable combustion grading is formed, the stability of combustion and the uniformity of the temperature of a combustion surface are ensured, and thus, local overheating cannot be formed in the combustion space 7, the generation of nitrogen oxides is effectively inhibited, and the content of the nitrogen oxides in the discharged flue gas is reduced.

When the air quantity input by the fire exhaust gap is reduced or no air inlet hole is formed, air mainly enters the combustion device 3 through or only through the inlet of the fire exhaust 32, so that the air flow speed of the outlet (the thick side combustion port 40 and the thin side combustion port 41) of the fire exhaust 32 is increased, the flow speed of high-temperature flue gas generated by combustion is high, the residence time of the flue gas in a high-temperature area is short, the generation reaction of nitrogen oxides is inhibited, and the quantity of nitrogen oxides discharged by the whole gas water heating device is reduced.

Please continue to refer to fig. 1-9. In a preferred embodiment of the present application, a gas water heating apparatus is provided comprising: the combustion device 3, the heat exchanger 2 and the fan 1 are arranged in sequence. The heat exchanger 2 is a fin type heat exchanger. The combustion device 3 includes a frame 31 and a plurality of fire rows 32 provided in the frame 31. The gas water heating device is provided with a gas supply device 4 for inputting gas into the fire grate. The fire row 32 includes mixing chambers and combustion ports 42. Air and fuel gas provided by the fuel gas supply device 4 enter a fire row mixing cavity through an air inlet of the fire row 32, and are mixed in the mixing cavity and then burnt at the combustion port to form a combustion surface.

In this embodiment, the fire row 32 is a shade fire row. The thick and thin fire row 32 has a thin side combustion port 41 and a thick side combustion port 40. The long thick side combustion ports 40 are distributed on both sides of the thin side combustion port 41. The light side burner 41 is honeycomb or honeycomb-like. Wherein, 8-20 light side combustion ports 41 are uniformly arranged on the fire row 32 in unit square centimeter. Specifically, the size of the light side combustion port is 3-8 square millimeters.

In the present embodiment, a baffle 35 is provided upstream of the plurality of fire rows 32. The baffle 35 is horizontally disposed and has a rectangular structure. The baffle 35 may be provided with or without an air inlet hole communicating up and down. When the baffle is provided with an air inlet, the aperture ratio of the air inlet on the baffle is below 3%.

In this embodiment, when the air amount input from the outside of the fire grate 32 is reduced or the air entering from the outside of the fire grate is completely eliminated, the air enters the combustion device mainly through or only through the inlet of the fire grate 32, so that the airflow speed of the combustion port 42 of the fire grate is increased, the flow speed of high-temperature flue gas generated by combustion is high, the residence time of the flue gas in the high-temperature area is short, the generation reaction of nitrogen oxides is inhibited, and the amount of nitrogen oxides discharged by the whole gas water heating device is reduced.

In addition, simultaneously, fan 1 sets up in heat exchanger 2's low reaches, and the negative pressure that forms in the air inlet space draws under the effect and evenly gets into in every fire row 32, is favorable to every fire row 32 burning to form uniform flame to form the even combustion surface of temperature in combustion space 7, reduce the nitrogen oxide content in the burning flue gas.

In addition, when the fin type heat exchanger 2 is used, the fan 1 is located at the downstream of the heat exchanger 2, and the fins of the fin type heat exchanger can play a good role in rectifying and equalizing pressure on the air flow formed by the suction of the fan 1, so that a space with uniform pressure is formed in the combustion space 7, a combustion surface with better uniformity and integrity is formed conveniently, the temperature of the combustion surface is distributed uniformly, a local temperature overheating area cannot be generated in the combustion space 7, and the formation of nitrogen oxides is reduced.

Further, since the light-side combustion ports 41 are small in pore diameter and uniformly distributed, which can uniformly distribute the mixed gas inputted from the fire grate (the mixed gas of the fuel gas and the air) into each light-side combustion port 41, the combustion surface (a part of the entire combustion surface) formed at the light-side combustion ports 41 can be regarded as being formed by uniform small flames, the combustion temperature of the combustion surface is more uniform, so that the amount of nitrogen oxides generated in the combustion process is reduced.

In the gas water heating device in the embodiment, the fan 1 is arranged at the downstream of the heat exchanger 2, so that air entering an air inlet space uniformly enters each fire row 32 to form primary uniformity; the thick and thin fire rows with honeycomb structures or honeycomb-like structures are adopted to form a combustion surface with uniform temperature, so that secondary uniformity is formed; and then, a space with uniform pressure is formed in the combustion space 7 by utilizing the rectification and pressure equalizing effects of the fin type heat exchanger, and three times of uniformity is formed, so that the content of nitrogen oxides in the flue gas is reduced.

In addition, when the air quantity input from the outside of the fire row 32 is reduced or the air entering from the outside of the fire row is thoroughly eliminated, the air mainly enters the combustion device through or only through the inlet of the fire row 32, so that the probability of resonance generated during combustion of the fire row can be reduced, combustion noise is reduced, and the use experience of a user is improved.

Any numerical value recited herein includes all values of the lower and upper values that increment by one unit from the lower value to the upper value, as long as there is a spacing of at least two units between any lower value and any higher value. For example, if it is stated that the number of components or the value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, more preferably from 30 to 70, then the purpose is to explicitly list such values as 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc. in this specification as well. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be explicitly recited in this description, and all possible combinations of values recited between the lowest value and the highest value are believed to be explicitly stated in the description in a similar manner.

Unless otherwise indicated, all ranges include endpoints and all numbers between endpoints. "about" or "approximately" as used with a range is applicable to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30," including at least the indicated endpoints.

All articles and references, including patent applications and publications, disclosed herein are incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not substantially affect the essential novel features of the combination. The use of the terms "comprises" or "comprising" to describe combinations of elements, components, or steps herein also contemplates embodiments consisting essentially of such elements, components, or steps. By using the term "may" herein, it is intended that any attribute described as "may" be included is optional.

Multiple elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, component, section or step is not intended to exclude other elements, components, sections or steps.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated herein by reference for the purpose of completeness. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to forego such subject matter, nor should the inventors regard such subject matter as not be considered to be part of the disclosed subject matter.

Claims

1. The thick and thin fire grate is characterized by comprising a mixing cavity and a combustion port; the thick fire row and the thin fire row are provided with a first air inlet and a second air inlet; the combustion port comprises a rich side combustion port communicated with the first air inlet and a lean side combustion port communicated with the second air inlet; the concentration of the fuel gas in the gas input by the first gas inlet is greater than that in the gas input by the second gas inlet; the thick side combustion port is positioned at two sides of the thin side combustion port along the length direction perpendicular to the thick and thin fire row.

2. The shade fire row of claim 1, wherein: the size of the light side combustion port is below 10 square millimeters.

3. The shade fire row of claim 2, wherein: the size of the light side combustion port is 3-8 square millimeters.

4. A fire grate as claimed in any one of claims 1 to 3 wherein: 3-20 light side combustion ports are uniformly distributed in unit square centimeter.

5. The shade fire row of claim 1, wherein: the light side combustion port is of a honeycomb structure or a honeycomb-like structure.

6. The shade fire row of claim 1, wherein: the thick and thin fire row comprises an inner core assembly and a shell; the inner core assembly extends along the length direction of the thick and thin fire row; a long-strip-shaped thick-side combustion port is formed between the shell and the inner core assembly; the light side burner port is formed on the inner core assembly.

7. The shade fire row of claim 6, wherein: the inner core assembly is formed by stamping, bending or stamping, welding.

8. The shade fire row of claim 7, wherein: the inner core assembly comprises a plurality of stamping plates, and grooves formed by stamping of two adjacent stamping plates are aligned to form the light side combustion port.

9. The shade fire row of claim 8, wherein: the stamping plates are single stamping plate bodies which are bent to form the inner core assembly, or the two ends of the stamping plates are fixed together through welding to form the inner core assembly.

10. The shade fire row of claim 1, wherein: the first air inlet and the second air inlet are arranged up and down.

11. The shade fire row of claim 10, wherein: the first air inlet is positioned below the second air inlet, the area of the second air inlet is smaller than that of the first air inlet, and the amount of fuel gas input by the second air inlet is smaller than that input by the first air inlet.

12. The shade fire row of claim 1, wherein: the plurality of light side combustion ports are arranged in close proximity and are uniformly distributed.

13. The shade fire row of claim 12, wherein: the light side combustion ports in each row are distributed along the length direction of the thick and light fire row, and the light side combustion ports in two adjacent rows are staggered.

14. A combustion apparatus comprising a housing and a plurality of the light-shade fire rows of any one of claims 1 to 12 disposed within the housing.

15. The combustion apparatus of claim 14 wherein more than 85% of the air entering said combustion apparatus enters a plurality of said light-shade fire rows.

16. The combustion apparatus of claim 14 wherein all of the air entering the combustion apparatus enters the light-shade fire row; the combustion device is configured such that air cannot enter the combustion space from outside the light-shade fire row.

17. The combustion apparatus of claim 16 wherein a baffle is provided in said housing; the baffle is arranged at the upstream of the thick fire row and the thin fire row; the baffle plate is arranged so that all air entering the combustion device enters the thick and thin fire row, and air cannot enter the combustion space from the outside of the thick and thin fire row.

18. The combustion apparatus of claim 14 wherein said combustion apparatus is provided with a spacing structure separating a combustion space from an intake space upstream of said combustion space; the interval structure is provided with a communication part for communicating the combustion space with the air inlet space; part of air in the air inlet space can enter the thick and thin fire row, and part of air can enter the combustion space from the outside of the thick and thin fire row through the communication part; the area ratio of the communicating portion to the spacing structure is less than 5%.

19. The combustion apparatus of claim 18, wherein: the area ratio of the projection of the communication part and the interval structure on the horizontal plane is less than 5%.

20. The combustion apparatus of claim 18, wherein: the air input by the communicating part enters a gap between two adjacent thick and thin fire rows, and the area ratio of the communicating part and the interval structure is less than 1%.

21. The combustion apparatus of claim 18, wherein: the interval structure comprises a baffle plate arranged in the frame body; the baffle is arranged at the upstream of the thick fire row and the thin fire row.

22. The combustion apparatus of claim 21, wherein: the communication part comprises an air inlet hole arranged on the baffle plate; the opening rate of the air inlet hole on the baffle plate is below 3%.

23. The combustion apparatus of claim 21, wherein: gaps between the plurality of shade fire rows and the shade fire rows form a burner; the burner is not provided with the communication part in the projection area of the baffle plate along the vertical direction.

24. The combustion apparatus of claim 21, wherein: gaps between the plurality of shade fire rows and the shade fire rows form a burner; the communication part is arranged in an area of the burner outside the projection area of the baffle plate along the vertical direction.

25. The combustion apparatus of claim 22, wherein: the baffle is a rectangular plate; the air inlet is arranged close to the side edge of the baffle plate.

26. A gas water heating apparatus, comprising: a combustion device according to any one of claims 14 to 25.

27. The gas water heating apparatus of claim 26, further comprising a heat exchanger and a fan, wherein the combustion apparatus, the heat exchanger and the fan are arranged in sequence.

28. The gas water heater as claimed in claim 27, wherein the gas water heater is provided with a gas supply means for supplying gas to the thick and thin fire grate, and air and gas supplied from the gas supply means enter the grate mixing chamber through the first and second gas inlets of the thick and thin fire grate, and are mixed in the mixing chamber and combusted at the combustion port to form a combustion surface.

29. A gas water heating apparatus as claimed in claim 28 wherein the area ratio of said combustion ports to said combustion surfaces of said plurality of light and dark fire rows is greater than 90%.

30. A gas water heating apparatus as claimed in claim 29, wherein a combustion space is provided between said plurality of said light and dark fire rows and said heat exchanger, and flames of said plurality of light and dark fire rows passing through said combustion ports are mutually fused to form a complete combustion surface in said combustion space.

31. The gas water heating apparatus as recited in claim 27, wherein the heat exchanger is a fin heat exchanger.