CN115183234A

CN115183234A - Gas distribution device, combustor and gas equipment

Info

Publication number: CN115183234A
Application number: CN202110365429.0A
Authority: CN
Inventors: 梁泽锋; 李鑫; 钱晓林; 陆祖安
Original assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Priority date: 2021-04-02
Filing date: 2021-04-02
Publication date: 2022-10-14

Abstract

The invention discloses a gas distribution device, a burner and gas equipment, wherein the gas distribution device comprises: the gas distribution chamber, the air inlet and the air outlet which are respectively communicated with the gas distribution chamber are formed in the shell; and the cooling channel is arranged in the shell, and an input interface and an output interface which are communicated with the cooling channel are formed on the shell. The cooling channel arranged on the gas distribution device is adopted to exchange heat with the shell, and the cooling of the gas flow passing through the gas distribution chamber is realized through the cooling shell, so that the initial temperature of the gas flow output by the gas distribution device is reduced, and the tempering caused by overhigh temperature of the output gas flow is avoided.

Description

Gas distribution device, combustor and gas equipment

Technical Field

The invention relates to the field of gas equipment, in particular to a gas distribution device, a combustor and gas equipment.

Background

In the operation process of the gas water heater, gas is injected into a combustion chamber of the combustor, ignition is carried out through the ignition device, mixed gas in the combustion chamber is ignited to form high-temperature flue gas, and the high-temperature flue gas enters the heat exchanger to exchange heat with the heat exchange tube to form hot water. The low-temperature flue gas formed by heat exchange is discharged from a smoke discharge pipe of the water heater in a specified direction. Because the injected gas burns to form high-temperature flue gas, the part of the injected gas in the combustor is easy to generate high temperature, the temperature of the injected gas is high, and the tempering of the combustor is easy to cause.

Disclosure of Invention

The invention mainly aims to provide a gas distribution device, a burner and gas equipment, aiming at improving the tempering caused by overhigh temperature of the gas sprayed by the existing burner.

In order to achieve the above object, the present invention provides a gas distribution device, including:

the gas distribution device comprises a shell, a gas inlet and a gas outlet, wherein the shell is provided with a gas distribution chamber, and the gas inlet and the gas outlet are communicated with the gas distribution chamber; and

and the cooling channel is arranged in the shell, and an input interface and an output interface which are communicated with the cooling channel are formed on the shell.

Optionally, the housing comprises:

a front wall; and

the rear wall is arranged opposite to the front wall, the cooling channel is a hollow cavity arranged in the front wall and/or the rear wall, and the front wall and the rear wall are enclosed to form the gas distribution chamber.

Optionally, the front wall and the rear wall are respectively provided with the cooling channels, and the cooling channels of the front wall and the rear wall are communicated with each other.

Optionally, the housing comprises:

a front wall;

a rear wall disposed opposite the front wall, the front wall and the rear wall forming the cooling passage therebetween; and

and the inner annular wall penetrates through the cooling channel, and the gas distribution chamber is formed inside the inner annular wall.

Optionally, the housing comprises:

a front wall;

a rear wall disposed opposite the front wall, the front wall and the rear wall forming the gas distribution chamber therebetween; and

a cooling tube disposed through the front wall and/or the rear wall, the cooling tube having the cooling passage formed therein.

Optionally, the gas distribution device further comprises:

the nozzle is located the gas outlet, the quantity of nozzle is a plurality of, and is a plurality of the nozzle interval sets up.

Optionally, the housing comprises:

the main body section is provided with a first end and a second end which are arranged oppositely, and the air inlet is arranged at the first end of the main body section; and

the gas distribution chamber extends from the first end of the main body section to the fourth end of the output section;

the direction from the first end to the second end of the main body section is a first direction, the direction from the third end to the fourth end of the output section is a second direction, and the first direction and the second direction are arranged at an included angle.

Optionally, the cooling channel is disposed proximate to the air outlet.

The invention also proposes a burner for a gas-fired apparatus, said burner comprising:

the combustion chamber comprises a shell, a first combustion chamber and a second combustion chamber, wherein the first combustion chamber and the second combustion chamber are communicated with each other;

the preheating burner is arranged on the shell and used for combusting to form mixed gas so as to heat the air in the first combustion chamber to a preset temperature and convey the air to the second combustion chamber;

the gas distribution device described above is provided in the casing, and injects gas into the second combustion chamber so as to cause a high-temperature air combustion reaction to proceed in the second combustion chamber.

Optionally, the burner further comprises:

the premixer is arranged on the shell and is used for connecting gas and air to form mixed gas after premixing and conveying the mixed gas to the preheating burner and the gas distribution device.

Optionally, the burner further comprises:

the distributor is arranged on the shell, is connected with the premixer and is used for conveying mixed gas formed by the premixer to the preheating burner and the gas distribution device respectively.

The invention also proposes a gas appliance comprising:

a body;

the combustor is arranged on the machine body; and

and the heat exchanger is arranged on the machine body, is connected with the second combustion chamber and is used for exchanging heat with flue gas generated by combustion reaction of high-temperature air of the combustor.

According to the technical scheme, the cooling channel arranged on the gas distribution device is adopted to exchange heat with the shell, and the cooling of the gas flow flowing through the gas distribution chamber is realized through the cooling shell, so that the initial temperature of the gas flow output by the gas distribution device is reduced, and the tempering caused by overhigh temperature of the output gas flow is avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a front view of one embodiment of the gas distribution device of the present invention;

FIG. 2 is a top view of one embodiment of the gas distribution device of the present invention;

FIG. 3 is a left side view of one embodiment of the gas distribution device of the present invention;

FIG. 4 is a schematic structural diagram of an embodiment of the housing of the present invention;

FIG. 5 isbase:Sub>A sectional view taken along line A-A of FIG. 4;

FIG. 6 is a sectional view taken along line B-B in FIG. 5;

FIG. 7 is a front view of one embodiment of the water heater of the present invention;

FIG. 8 is a right side view of an embodiment of the water heater of the present invention.

The reference numbers illustrate:

reference numerals	Name(s)	Reference numerals	Name(s)
				10	Machine body	11	Heat exchanger
12	Heat exchange tube	13	Smoke collecting hood
				20	Outer cover	21	Preheating burner
22	Premixing device	23	Air inlet
				24	Gas inlet	25	Dispenser
30	Shell body	301	Main body segment
				302	Output section	31	Gas distribution chamber
32	Cooling channel	321	Input interface
				322	Output interface	33	Front wall
34	Rear wall	35	Side wall
				36	Inner ring wall	37	Nozzle with a nozzle body

The implementation, functional features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as upper, lower, left, right, front, rear, 8230; \8230;) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components in a specific posture (as shown in the figure), the motion situation, etc., and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides a fuel gas distribution device which is used for a combustor, and the fuel gas distribution device is provided with a gas inlet and a gas outlet, wherein the gas outlet is communicated with the inside of a combustion chamber of the combustor and is used for spraying fuel gas or a mixture of the fuel gas and air to the inside of the combustor so as to enable the inside of the combustor to be ignited and then combusted to form high-temperature flue gas. The combustor is used for electrical equipment, such as a water heater, heating equipment, a wall-mounted furnace and the like, which heat exchanges through high-temperature flue gas to heat a medium. The following description will be given taking the gas appliance as a gas water heater as an example. Fig. 1 to 8 are corresponding drawings of an embodiment of the present invention.

Referring to fig. 1 to 4, in an embodiment, the gas distribution device includes: a housing 30, wherein the housing 30 is provided with a gas distribution chamber 31 and a gas inlet and a gas outlet which are respectively communicated with the gas distribution chamber 31; the air inlet of the housing 30 may be used for connecting an external air source pipeline or a blower, and air enters the air distribution chamber 31 through the air inlet and is output to the air outlet in the combustor through the air distribution chamber 31.

And a cooling passage 32 provided in the housing 30, wherein an input port 321 and an output port 322 communicating with the cooling passage 32 are formed in the housing 30. The cooling channel 32 is used for circulating a cooling medium, and the cooling medium enters the cooling channel 32 through the input interface 321, and flows along the cooling channel 32 to the output interface 322.

The cooling channel 32 is used for conveying a cooling medium, the cooling medium exchanges heat with the inner wall surface of the cooling channel 32 to further cool the housing 30, and the housing 30 exchanges heat with the gas flowing through the gas distribution chamber 31 to cool the gas, so as to reduce the initial temperature of the gas output from the gas outlet. The cooling medium is water as an example.

The output interface 322 of the cooling medium can be communicated with the heat exchange pipe 12 of the water heater, and the input interface 321 can be directly communicated with the water inlet valve of the water heater. Cold water enters the cooling channel 32 from the input port 321 and is output by the output port 322. The cooling passage 32 may be provided along a longitudinal direction or a width direction of the gas distribution device, and one or a plurality of the cooling passages 32 may be provided inside the casing 30. When a plurality of the cooling passages 32 are provided, the plurality of the cooling passages 32 may be communicated with each other or may be provided independently of each other.

Referring to fig. 2 and 3, in an embodiment, the gas distribution device further includes: and a plurality of nozzles 37 provided at the air outlet, wherein the plurality of nozzles 37 are provided at intervals. The nozzle 37 is used for communicating with the gas outlet to inject gas. By arranging the nozzle 37, the angle of the nozzle 37 can be adjusted as required to change the jet direction of the air flow, thereby adjusting the direction of the flame. By adjusting the inner diameter of the nozzle 37, the flow and velocity of the air flow can be controlled, thereby changing the combustion state of the flame.

Referring to fig. 3, optionally, in an embodiment, the housing 30 includes: the main body section 301 has a first end and a second end which are opposite to each other, and the air inlet is arranged at the first end of the main body section 301; and an output section 302, the output section 302 having a third end and a fourth end, the third end of the output section 302 being connected to the second end of the main body section 301, the gas outlet being provided at the fourth end of the output section 302, the gas distribution chamber 31 extending from the first end of the main body section 301 to the fourth end of the output section 302; the direction from the first end to the second end of the main body segment 301 is a first direction, the direction from the third end to the fourth end of the output segment 302 is a second direction, and the first direction and the second direction form an included angle.

For example, as shown in fig. 3, the first direction is perpendicular to the second direction, chambers for conveying gas are respectively formed in the main body section 301 and the output section 302, the main body section 301 and the output section 302 are connected to each other, so that the chambers formed by the two sections are communicated with each other to form the gas distribution chamber 31, and the gas flow enters the gas distribution chamber 31 from the gas inlet at the first end of the main body section 301, flows along the main body section 301 to the output section 302, and is output to the combustion chamber for combustion from the gas outlet of the output section 302.

Referring to fig. 5 and 6, the gas outlet is disposed toward the interior of the combustion chamber, the housing 30 is divided into two parts, and the two parts are respectively formed into chambers to form a gas flow channel of the gas distribution chamber 31 in combination, when the gas flow is output along the gas outlet of the output section 302, the gas outlet is spaced from the main body section 301, and when the gas is jetted and combusted to form a flame, the flame is spaced from the main body section 301, so that the main body section 301 is prevented from being rapidly heated, which helps to reduce the heating of the gas flow when the gas flow passes through the main body section 301, and helps to reduce the initial temperature of the gas flow. Since the inner flame temperature of the flame is relatively low during the gas jet combustion, the output section 302 can be used to extend the distance between the outer flame of the flame and the main body section 301, thereby avoiding the influence of the high temperature of the combustion flame on the main body section 301. Under further action of the cooling passage 32, the initial temperature of the airflow output from the output section 302 can be further reduced. Because the first direction with the second direction is the contained angle setting, can change the air current outgoing direction of gas outlet, and then need not receive the space demonstration at the place of combustor, will the casing is as one of them wall of combustor makes the gas orientation that the gas outlet jetted the combustion chamber of combustor, with make full use of combustor inner space. Further through right cooling channel is right the casing cools down, because when the gas combustion that the gas outlet jetted formed flame, the inner flame temperature was lower, and outer flame kept away from the main part section, can further reduce the influence of high temperature flame to the combustor internal wall face, can improve the deformation that the combustor internal wall face leads to owing to long-time high temperature, and then promote the security performance of combustor.

The cooling passage 32 may be a hollow chamber provided inside a wall surface of the housing 30, and the hollow chamber forms the cooling passage 32. A pipe line provided inside the wall surface of the casing 30 or a pipe line penetrating the gas distribution chamber 31 may be used, and the cooling passage 32 may be formed inside the pipe line. The shape and location of the cooling passage 32 may be determined according to the shape of the housing 30.

Optionally, the cooling channel 32 is disposed proximate to the air outlet. The cooling channel 32 is configured to cool the air flow output from the air outlet, so as to reduce an initial temperature of the air flow output from the air outlet. When the housing 30 includes the main body section 301 and the output section 302, the cooling passage 32 may be provided in the output section 302. The output section 302 is in a state of keeping the airflow output position away from the main body section 301, and because the air outlet of the output section 302 is used for outputting the airflow, the flame generated by airflow jet combustion is closer to the fourth end of the output section 302, and the influence of high-temperature flame on the output section 302 is greater. The air current along in the main part section 301 flow process, can take away the heat of main part section 301, when the air current was taken the heat to output section 302, cooling channel 32 can be right output section 302 is cooled down, avoids output section 302 and air current carry out the heat exchange and lead to the problem that emergent air current temperature rose, and the realization is right simultaneously main part section 301 cools down. Because the cooling channel 32 can directly act on the air flow flowing through the air outlet for cooling, the cooling capacity of the cooling medium directly acts on the air flow flowing through the output section 302, and the utilization rate of the cooling capacity is further improved.

In one embodiment, the housing 30 includes: a front wall 33; and a rear wall 34 disposed opposite to the front wall 33, wherein the cooling channel 32 is a hollow chamber disposed in the front wall 33 and/or the rear wall 34, and the front wall 33 and the rear wall 34 enclose the gas distribution chamber 31.

The housing may further comprise side walls 35 for connecting the front and rear walls to enclose a chamber.

The front wall 33 and the rear wall 34 are two wall surfaces disposed opposite to each other, and a gap between the front wall 33 and the rear wall 34 forms the gas distribution chamber 31. The cooling channels 32 are arranged through the front wall and/or the rear wall 34 for heat exchange with the front wall 33 and/or the rear wall 34 for reducing the temperature of the gas flow in the gas distribution chamber 31.

In order to improve the cooling efficiency, optionally, the front wall 33 and the rear wall 34 are respectively provided with the cooling channels 32, and the cooling channels 32 of the front wall 33 and the rear wall 34 are communicated with each other, so that a cooling medium circulation channel is formed in the housing 30, and the input interface 321 and the output interface 322 are conveniently provided.

When the housing 30 is molded, the cooling channel 32 is formed inside the housing 30, so that the cooling channel 32 and the gas distribution chamber 31 are isolated from each other, and the gas flow is cooled without affecting the gas flow delivery of the gas distribution chamber 31.

When the housing 30 includes the main body section 301 and the output section 302, the ends of the front wall 33 and the rear wall 34 near the gas outlet may be bent toward the inside of the burner, so that the end of the gas outlet of the gas distribution chamber 31 forms the output section 302 protruding toward the inside of the burner. The cooling passage 32 may extend from the main body section 301 to the output section 302 in the front wall 33 and/or the rear wall 34 to increase the area of the cooling passage 32, or the cooling passage 32 may be provided only at one end of the front wall 33 and/or the rear wall 34 near the output section 302 to concentrate the cooling medium on the air flow at the air outlet.

Referring to fig. 5 and 6, in another embodiment, the housing 30 includes: a front wall 33; a rear wall 34 disposed opposite the front wall 33, the front wall 33 and the rear wall 34 forming the cooling passage 32 therebetween; and an inner annular wall 36 penetrating the cooling passage 32, the inner annular wall 36 forming the gas distribution chamber 31 therein. A cavity for accommodating the inner annular wall 36 is formed between the front wall 33 and the rear wall 34, a hollow chamber is formed inside the inner annular wall 36, the hollow chamber forms the gas distribution chamber 31, the inner annular wall 36 has a first surface facing the front wall 33, the first surface and an inner wall surface of the front wall 33 form the cooling channel 32 therebetween, and/or the inner annular wall 36 has a second surface facing the rear wall 34, the second surface and the inner wall surface of the rear wall 34 form the cooling channel 32 therebetween.

The inner annular wall 36 corresponds to the shape of the housing 30 and serves to divide a separate space for the flow of the transport gas in the cooling channel 32 formed between the front wall 33 and the rear wall 34 to form the gas distribution chamber 31. The inner annular wall 36 may be a plurality of tubes independently disposed within the cooling gallery 32 or may be a shell-like structure conforming to the interior shape of the cooling gallery 32 of the housing 30.

In yet another embodiment, the housing 30 includes: a front wall 33; a rear wall 34 disposed opposite to the front wall 33, the front wall 33 and the rear wall 34 forming the gas distribution chamber 31 therebetween; and a cooling pipe inserted through the front wall 33 and/or the rear wall 34, the cooling pipe having the cooling passage 32 formed therein. The cooling pipe is a pipe penetrating the front wall 33 and/or the rear wall 34 for heat exchange with the front wall 33 and/or the rear wall 34.

When the housing 30 includes the main body section 301 and the output section 302, the cooling pipe may be provided in the main body section 301 and/or the output section 302, or the cooling pipe may be provided only in the output section 302.

The invention also provides an embodiment of the burner, and the burner is used for gas equipment.

Referring to fig. 7 and 8, in an embodiment, the burner includes: a housing 20, in which a first combustion chamber and a second combustion chamber communicating with each other are formed; a preheating burner 21, disposed in the housing 20, for burning to form a mixed gas, so as to heat the air in the first combustion chamber to a preset temperature, and delivering the heated air to the second combustion chamber; the gas distribution device according to any one of the above embodiments is provided in the casing 20, and is configured to inject gas into the second combustion chamber so as to cause a high-temperature air combustion reaction to proceed in the second combustion chamber.

The gas distribution device is used for inputting gas or mixed gas of gas and air into the second combustion chamber. When the burner is operated, a cooling medium enters the cooling channel 32 from the input port to cool the gas flow of the gas distribution device, so that the initial temperature of the gas flow output by the gas distribution device is reduced, and the problem of backfire in the gas combustion in the second combustion chamber is avoided. The gas distribution device may further be provided with a control valve for controlling the flow of gas into the gas distribution chamber 31 to adjust the gas flow according to the combustion load of the burner.

Optionally, the burner further comprises: the premixer 22 is arranged in the housing 20, and is used for introducing gas and air for premixing to form mixed gas and conveying the mixed gas to the preheating burner 21 and the gas distribution device. The premixer 22 has an air inlet 23 and a gas inlet 24 for introducing air and gas, respectively, mixed to form a mixture and delivered to the preheating burner 21 and the gas distribution device. The premixer 22 performs gas premixing, which can improve the uniformity of gas and contribute to improving the combustion efficiency of gas.

Further optionally, the burner further comprises: and a distributor 25 disposed in the casing 20, connected to the premixer 22, and configured to deliver the mixed gas formed by the premixer 22 to the preheating burner 21 and the gas distribution device, respectively. The distributor 25 has an inlet end connected to the premixer 22 and an outlet end connected to the preheating burner 21 and the gas distribution device, respectively, to achieve predistribution of the gas.

Preheating burner 21 is used for the burning to form the mist of high temperature, the mist of high temperature with air mixture in the first combustion chamber, so that air heating in the first combustion chamber is to predetermineeing the temperature and carry extremely the second combustion chamber is detected first combustion chamber carries extremely when gas in the second combustion chamber reaches and predetermines the temperature, the gas distributor to injection gas in the second combustion chamber, gaseous is in carry out the high temperature air burning in the second combustion chamber, form the high temperature flue gas.

And the second combustion chamber carries out high-temperature air combustion reaction. During the combustion reaction of the high-temperature air, the chemical reaction needs to occur in a high-temperature low-oxygen environment, the temperature of reactants is higher than the autoignition temperature of the reactants, the maximum temperature rise in the combustion process is lower than the autoignition temperature of the reactants, and the volume fraction of oxygen is diluted to an extremely low concentration by combustion products. Compared with the conventional combustion, in the combustion state, the pyrolysis of the fuel is inhibited, the flame thickness is thickened, the flame front surface disappears, so that the temperature of the whole second combustion chamber is very uniform, the combustion peak temperature is low, the noise is extremely low, and the emission of pollutants of nitrogen oxide and carbon monoxide is greatly reduced. However, achieving high temperature air combustion requires certain conditions: the oxygen concentration in most areas in the furnace is required to be ensured to be lower than a certain value, generally lower than 5% -10%, the gas is ensured to be fully combusted and uniformly combusted, the temperature is higher than the self-ignition point of the fuel, and the self-ignition is maintained. The preset temperature of the mixed flue gas reaches the autoignition temperature of the fuel gas injected by the fuel gas distribution device, so that the fuel gas injected by the fuel gas distribution device can maintain autoignition in the second combustion chamber.

Since the air in the first combustion chamber can supplement the combustion of the gas injected by the preheating burner 21, the oxygen concentration in the mixed smoke is relatively low, and the high-temperature air combustion reaction is suitable for being carried out in the second combustion chamber. When the gas injected by the gas distribution device is subjected to high-temperature air combustion, the energy consumption required for combustion is reduced. A fan may be provided outside the burner to supply air into the first combustion chamber, or another structure may be provided outside the burner to supply air into the first combustion chamber.

The preheating burner 21 rapidly preheats the air in the first combustion chamber through the first combustion chamber, so that the heat load ratio in the first combustion chamber is adjusted to be within the range of 20-50%, and the emission of nitrogen oxides and carbon monoxide in the mixed flue gas formed by the first combustion chamber is controlled to be about 10 ppm. Because the high-temperature air combustion is volume combustion or dispersion combustion, the reaction rate is low, the local heat release is less, the heat flow distribution is uniform, the combustion peak temperature is low, and the noise is extremely low.

Compared with the traditional local high-temperature combustion in a small area, the high-temperature air combustion of the 16L gas water heater with the combustor in the embodiment has the advantages that the reaction is carried out in a large area or even in the whole second combustion chamber, and the flame front in the second combustion chamber disappears; the generation of pollutants such as nitrogen oxides, carbon monoxide and the like is obviously reduced; the overall temperature of the second combustion chamber is increased, and the radiation heat transfer is enhanced. The second combustion chamber is combusted to form high-temperature flue gas, and the heat load of the second combustion chamber is 50-80%. The heat load ratio of the second combustion chamber is controlled in the range, so that the soft combustion is achieved in the second combustion chamber, the purpose of low-noise combustion is achieved, the combustion noise of the gas water heater can be reduced, and the environmental pollution caused by the fact that high-temperature smoke generated by high-temperature air combustion is rich in nitrogen and carbon dioxide is relatively reduced.

The invention also provides an embodiment of the gas equipment.

Referring to fig. 7 and 8, the gas appliance includes: a body 10; the burner according to any of the above embodiments, provided in the machine body 10; and the heat exchanger 11 is arranged on the machine body 10, is connected with the second combustion chamber, and is used for exchanging heat with flue gas generated by combustion reaction of high-temperature air of the combustor. The gas equipment can be equipment for forming heat through gas combustion and carrying out heat transfer for water heaters, wall-mounted furnaces and the like.

The heat exchanger 11 has a preset heat load range according to a required working condition, and high-temperature air of the combustor is combusted to generate high-temperature flue gas to exchange heat with the heat exchange tube 12 of the heat exchanger 11, so that hot water is generated. The water heater can also comprise a smoke collecting hood 13 and a smoke exhaust pipe, and cooling smoke generated by heat exchange of the heat exchanger 11 is exhausted to the smoke exhaust pipe through the smoke collecting hood 13 so as to exhaust the smoke to a preset direction and a preset position.

Claims

1. A gas distribution device, characterized in that it comprises:

the gas distribution chamber, the air inlet and the air outlet which are respectively communicated with the gas distribution chamber are formed in the shell; and

2. The gas distribution device of claim 1, wherein the housing comprises:

a front wall; and

3. The gas distribution device as defined in claim 2, wherein said front wall and said rear wall are provided with said cooling passages, respectively, and the cooling passages of said front wall and said rear wall are in communication with each other.

4. The gas distribution device of claim 1, wherein the housing comprises:

a front wall;

5. The gas distribution device of claim 1, wherein the housing comprises:

a front wall;

a cooling tube inserted through the front wall and/or the rear wall, the cooling tube having the cooling passage formed therein.

6. The gas distribution device of claim 1, further comprising:

7. A gas distribution device according to any one of claims 1 to 6, wherein said housing comprises:

an output section having a third end and a fourth end, the third end of the output section being connected to the second end of the main body section, the gas outlet being provided at the fourth end of the output section, the gas distribution chamber extending from the first end of the main body section to the fourth end of the output section;

8. The gas distribution device of claim 7, wherein said cooling channel is disposed adjacent said gas outlet.

9. A burner for a gas-fired appliance, the burner comprising:

the gas distribution device according to any one of claims 1 to 8, provided in the casing, for injecting a gas into the second combustion chamber to cause a high-temperature air combustion reaction in the second combustion chamber.

10. The burner of claim 9, further comprising:

the premixer is arranged on the shell and used for being connected with gas and air to form mixed gas after premixing and conveying the mixed gas to the preheating burner and the gas distribution device.

11. The burner of claim 10, further comprising:

12. A gas-fired appliance, comprising:

a body;

a burner as claimed in any one of claims 9 to 11, provided in the body; and

and the heat exchanger is arranged on the machine body, is connected with the second combustion chamber and is used for exchanging heat with the flue gas generated by the combustion reaction of the high-temperature air of the combustor.