CN215723199U

CN215723199U - Combustor and gas equipment

Info

Publication number: CN215723199U
Application number: CN202022498091.XU
Authority: CN
Inventors: 钱晓林; 梁泽锋
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: 2020-10-30
Filing date: 2020-10-30
Publication date: 2022-02-01
Anticipated expiration: 2030-10-30

Abstract

The utility model discloses a combustor and gas equipment. The combustor comprises a combustion main body, an air inlet assembly, an air blowing assembly and a premixer, wherein the combustion main body forms a first combustion chamber and a second combustion chamber, and the combustion main body is used for heating the temperature in the first combustion chamber to a preset temperature; the air inlet assembly is used for connecting gas to the atmospheric combustor; the air blowing component is used for introducing air to the atmospheric burner; the pre-mixer is used for receiving and mixing fuel gas and air, and injecting mixed gas to the second combustion chamber so as to enable the second combustion chamber to carry out high-temperature air combustion. In the utility model, the gas provided by the gas inlet component entrains primary air to the first combustion chamber and ignites the primary air; the air blowing component blows secondary air into the first combustion chamber to generate high-temperature flue gas; the premixer injects mixed gas to the second combustion chamber, so that the mixed gas is matched with the high-temperature flue gas to generate entrainment effect, the high-temperature flue gas flows back, and the purpose of high-temperature air combustion is achieved.

Description

Combustor and gas equipment

Technical Field

The utility model relates to the technical field of high-temperature air combustion, in particular to a combustor and gas equipment.

Background

High temperature air combustion (high temperature air combustion) technology is a MILD combustion mode under low oxygen dilution conditions, also known as MILD combustion. The main combustion characteristics are as follows: low reaction rate, less local heat release, uniform heat flow distribution, low combustion peak temperature, low noise and the like. Because the MILD combustion temperature field is more uniform, the combustion peak temperature is low, the generation of thermal nitrogen oxides is reduced, and compared with a common combustion mode, the emission of pollutants NOx and CO can be greatly reduced.

Although high temperature air combustion has many of the advantages described above, it is currently an industrial application and is not used in everyday life.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims to provide a combustor with a high-temperature air combustion function and gas equipment.

To achieve the above object, the present invention provides a burner comprising:

the combustion body is formed with a first combustion chamber and a second combustion chamber which are sequentially communicated, and the combustion body is ignited in the first combustion chamber so as to heat the temperature in the first combustion chamber to a preset temperature;

the air inlet assembly is used for introducing gas into the atmospheric burner;

the air blowing assembly is used for introducing air to the atmospheric burner; and the number of the first and second groups,

and the premixer is used for introducing and mixing fuel gas and air and injecting mixed gas to the second combustion chamber so as to enable the second combustion chamber to carry out high-temperature air combustion.

In one embodiment, the combustion body comprises:

a housing forming the first combustion chamber and the second combustion chamber; and the number of the first and second groups,

the atmospheric burner is used for igniting in the first combustion chamber so as to heat the temperature in the first combustion chamber to a preset temperature.

In one embodiment, the premixer comprises a casing and a fan, the casing is formed with an air inlet channel, a fuel gas channel and a mixing cavity, an air inlet of the mixing cavity is communicated with the air inlet channel and the fuel gas channel respectively, and an air outlet of the mixing cavity is communicated with the second combustion chamber;

the fan is arranged on the air inlet duct.

In one embodiment, a plurality of injection ports are arranged at intervals on the side part of the second combustion chamber;

the premixer also comprises an air distribution structure, and the mixing cavity is communicated with the plurality of injection ports in a one-to-one correspondence manner through the air distribution structure.

In one embodiment, the gas distribution structure is provided with a gas distribution cavity, the gas distribution cavity comprises a first chamber and a second chamber which are sequentially communicated, the gas inlet of the first chamber is communicated with the mixing cavity, and the gas outlet of the second chamber is communicated with the second combustion chamber;

the second chamber is arranged along the gas flowing direction in a gradually expanding mode.

In one embodiment, two gas distributing structures are arranged on the gas distributing structure corresponding to two opposite sides of the second combustion chamber;

the mixing cavity is respectively communicated with the two gas distributing structures.

In one embodiment, the air intake assembly includes a gas pipe and a gas proportional valve, the gas pipe is respectively communicated with the first combustion chamber and the gas flow passage, and the gas proportional valve is used for respectively regulating gas flow of the first combustion chamber and the gas flow passage.

In one embodiment, the atmospheric burner comprises a combustion unit formed with an airflow channel, a combustion assembly arranged at an air outlet of the airflow channel, and an ignition device arranged in the first combustion chamber and used for igniting the combustion assembly.

In one embodiment, the gas flow channel is arranged in a curved manner along the flow direction of the mixed gas.

In one embodiment, the airflow passage has an intake passage section near an intake port of the airflow passage;

the gas inlet channel section is arranged in a way of flaring after necking along the flowing direction of the mixed gas.

In one embodiment, a plurality of the combustion units are arranged in the first combustion chamber side by side at intervals;

the gas inlet assembly comprises a gas pipeline and a gas distributing rod, and the gas pipeline is communicated with a plurality of gas flow channels of the combustion monomers in a one-to-one correspondence mode through the gas distributing rod.

In an embodiment, the burner further includes a control device and a flame sensing device, and the control device is electrically connected to the flame sensing device and the blowing assembly, so as to control the blowing assembly to operate when the flame sensing device senses that the combustion body is ignited.

In addition, in order to achieve the above purpose, the present invention further provides a gas appliance, which includes a heat exchanger and the burner as described above, wherein the heat exchanger produces hot water by using heat generated by the burner.

In an embodiment, the gas appliance comprises a gas water heater or a gas wall-hanging stove.

In the technical scheme provided by the utility model, the gas provided by the gas inlet assembly sucks primary air to the atmospheric burner and is ignited; secondary air is blown into the blowing component, and the combustion main body burns to generate high-temperature flue gas; after the premixer mixes air and fuel gas, mixed gas is injected into the second combustion chamber, so that the mixed gas is matched with high-temperature flue gas to generate entrainment effect, the high-temperature flue gas flows back, the heat preservation effect can be realized on the second combustion chamber, the temperature in the second combustion chamber is higher than the spontaneous combustion point of the fuel, and the spontaneous combustion of the fuel is realized; and dilution air can be sucked by jet flow, so that the oxygen concentration in the second combustion chamber is lower than a certain value, uniform combustion is realized, and the aim of high-temperature air combustion is fulfilled.

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 schematic front view of an embodiment of a combustor provided by the present invention;

FIG. 2 is an enlarged schematic view of the structure at A in FIG. 1;

FIG. 3 is a schematic longitudinal sectional view of the burner of FIG. 1;

fig. 4 is an enlarged schematic view of a portion B in fig. 3.

The reference numbers illustrate:

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

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below 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.

The utility model aims to design a novel burner by utilizing the combustion characteristic of high-temperature air and apply the novel burner to gas equipment, so that the gas equipment can effectively reduce the emission of CO and NOx and reduce the noise of the gas equipment.

The utility model provides a burner which is applied to gas equipment and related products and equipment such as a gas wall-mounted boiler and the like which are used for household bathing, heating and the like by using high-temperature hot water generated by gas combustion. Fig. 1 to 4 show an embodiment of a burner according to the present invention.

Referring to fig. 1 to 4, the burner provided by the present invention includes a combustion body, an air intake assembly 120, an air blowing assembly 130 and a pre-mixer 140, wherein the combustion body is formed with a first combustion chamber 101 and a second combustion chamber 102 which are sequentially communicated, and the combustion body is ignited in the first combustion chamber 101 to heat the temperature in the first combustion chamber 101 to a predetermined temperature; the air intake assembly 120 is used for introducing gas into the atmospheric burner 110; the blower assembly 130 is used for supplying air to the atmospheric burner 110; the premixer 140 is configured to receive and mix fuel gas and air, and inject the mixed gas into the second combustion chamber 102, so as to perform high-temperature air combustion in the second combustion chamber 102.

In the technical scheme provided by the utility model, the gas provided by the gas inlet component 120 entrains primary air to the atmospheric burner 110 and is ignited; the blowing assembly 130 blows secondary air, and the combustion main body burns to generate high-temperature flue gas; after the premixer 140 mixes the air and the fuel gas, the mixed gas is injected into the second combustion chamber 102, so that the mixed gas is matched with the high-temperature flue gas to generate a entrainment effect, the high-temperature flue gas flows back, a heat preservation effect can be realized on the second combustion chamber 102, the temperature in the second combustion chamber 102 is higher than the self-ignition point of the fuel, and the self-ignition of the fuel is realized; and dilution air can be sucked through jet flow, so that the oxygen concentration in the second combustion chamber 102 is lower than a certain value, uniform combustion is realized, and the purpose of high-temperature air combustion is achieved.

The specific expression of the combustion body is not limited in the present design, but for the sake of understanding, in the following embodiments, the combustion body includes a housing 100 and an atmospheric burner 110, wherein the housing 100 forms the first combustion chamber 101 and the second combustion chamber 102; the atmospheric burner 110 is used for igniting in the first combustion chamber 101 to heat the temperature in the first combustion chamber 101 to a preset temperature.

It is understood that the atmospheric burner 110 includes a combustion unit 111, the combustion unit 111 has a gas flow channel 112 for passing the combustion gas, in a specific application, the combustion unit 111 can be accommodated in the first combustion chamber 101, and the gas flow channel 112 of the combustion unit 111 is communicated with the first combustion chamber 101. The air intake assembly 120 provides the gas to the atmospheric burner 110, and when the gas directly enters the gas flow channel 112 or enters the gas flow channel 112 through the first combustion chamber 101, the gas sucks up part of the primary air in the indoor environment or in the first combustion chamber 101, and sufficient mixed gas is formed in the gas flow channel 112, so that the combustion unit 111 can be ignited.

Then, the blowing assembly 130 blows external air into the first combustion chamber 101 or the airflow channel 112, accelerates the circulation of the air, so that the single combustion unit 111 obtains more and continuous secondary air, realizes the continuous combustion of the single combustion unit 111, and can heat the temperature in the first combustion chamber 101 to a preset temperature, thereby realizing high-temperature preheating of the air. After the blowing assembly 130 blows external air into the first combustion chamber 101 or the airflow passage 112, dispersion of the air in the first combustion chamber 101 and the airflow passage 112 is facilitated, mixing of the air and the gas is facilitated, and thus stable combustion of the combustion body is facilitated. The blower assembly 130 may be disposed below the first combustion chamber 101, for example, at the bottom of the combustion body.

The premixer 140 receives outside air and outside gas, respectively, and after they are sufficiently mixed to form a mixed gas, injects the mixed gas into the second combustion chamber 102. Specifically, the premixer 140 may be provided with a nozzle communicating with the second combustion chamber 102, and the purpose of injecting the mixed gas into the second combustion chamber 102 can be achieved by providing a reduction in the flow area from the main structure of the premixer 140 to the nozzle, or by providing an increase in the pressure provided by the main structure of the premixer 140 to the nozzle, thereby achieving a high-speed jet.

After the mixed gas is injected into the second combustion chamber 102, the mixed gas is matched with the high-temperature preheated air in the second combustion chamber 102 to generate a entrainment effect, so that the high-temperature flue gas continuously flows back in the second combustion chamber 102. The circulating reflux of the high-temperature flue gas can play a role in heat preservation of the second combustion chamber 102, so that the temperature in the second combustion chamber 102 is higher than the spontaneous combustion point of the fuel, and the spontaneous combustion of the fuel is realized; the circulation reflux of the high-temperature flue gas can also entrain and dilute air through jet flow, so that the oxygen concentration in the second combustion chamber 102 is lower than a certain value, uniform combustion is realized, and the purpose of high-temperature air combustion is achieved.

It should be noted that, the structure of the above-mentioned burner frame can miniaturize the components for realizing high-temperature air combustion, so that more application space and value are provided, the noise is low, the combustion is sufficient, the pollution of discharged waste gas is small, when the burner frame is applied to related products and equipment such as gas wall-mounted furnaces and the like which use high-temperature hot water generated by gas combustion to perform household bathing, heating and the like, the requirements are met, and the effects of sufficient combustion and low pollutant discharge which cannot be provided by the burner in the existing water heater are also brought.

It can be understood that the target temperature of the high-temperature preheated air cannot be too low, and cannot be lower than 600 ℃, and generally, the target temperature is controlled to be 600-1200 ℃, so that when the high-temperature gas contacts with the fuel gas in the combustion chamber, better automatic combustion is realized, and ignition are not needed any more. The scheme for implementing high-temperature preheating of air can be various, and can be implemented by controlling the heating time, controlling the ratio of fuel gas to air, performing heat preservation, increasing the residence time of high-temperature gas in the second combustion chamber 102, and the like.

In the above, the oxygen concentration in the second combustion chamber 102 needs to be lower than a certain value, and specifically, may be set to be lower than 5% to 10%. The oxygen concentration in the second combustion chamber 102 can be achieved by adjusting the ratio of the fuel gas to the air in the premixer 140, for example, when the fuel gas amount is constant, the oxygen concentration in the second combustion chamber 102 can be adjusted by adjusting the real-time intake air amount in the second combustion chamber 102, thereby achieving the control of the ratio of the fuel gas to the air. The magnitude of the oxygen concentration in the second combustion chamber 102 may be controlled based on the size of the second combustion chamber 102 and the rate of control injection.

In one embodiment, the premixer 140 includes a casing and a blower 141, the casing is formed with an air inlet channel 142, a gas flow channel 143 and a mixing chamber 144, an air inlet of the mixing chamber 144 is communicated with the air inlet channel 142 and the gas flow channel 143, respectively, and an air outlet of the mixing chamber 144 is communicated with the second combustion chamber 102; the fan 141 is disposed in the air inlet duct 142. The fan 141 can accelerate the circulation of air in the air inlet duct 142, increase the flow rate of air, and contribute to high-speed jet. In the actual use process, if the fan 141 is arranged in the mixing cavity 144, in order to improve the safety, a special explosion-proof fan 141 needs to be selected, which increases the cost of the premixer 140 to a certain extent; in this embodiment, the fan 141 is disposed at the air inlet duct 142, which is helpful for reducing the specification requirement of the fan 141, thereby saving the cost. The setting of the fan 141 can adjust the specific air intake of the air intake duct 142 by adjusting the rotation speed of the fan blades in the fan 141, thereby adjusting the ratio of the fuel gas and the air in the mixing chamber 144.

Next, in an embodiment, a plurality of injection ports are arranged at intervals on the side of the second combustion chamber 102; where the premixer 140 further includes a nozzle, the nozzle may be arranged to be installed at the injection port, or the communication between the nozzle and the second combustion chamber 102 may directly constitute the injection port.

The specific arrangement mode of the plurality of injection ports is not limited, and in specific application, the plurality of injection ports can be arranged at intervals along the circumferential direction of the second combustion chamber 102, so that high-speed jet flow can be performed on the high-temperature flue gas in the second combustion chamber 102 from multiple directions, and the circulating reflux of the high-temperature flue gas is enhanced; or after the plurality of injection ports form one injection port group, at least two injection port groups are arranged on two opposite sides of the second combustion chamber 102, so that the airflow is injected oppositely to intensify the convection of the flue gas in the second combustion chamber 102.

The opening orientation of each of the plurality of ejection ports is also not limited. According to actual needs, the opening orientations of the plurality of injection ports may be arranged identically or at least partially differently. In one embodiment, when the plurality of injection ports are arranged at intervals in the circumferential direction of the second combustion chamber 102, the openings of all the injection ports may be arranged to face the central axis of the second combustion chamber 102; alternatively, all the injection ports may be arranged obliquely along the same side of the second combustion chamber 102 in the circumferential direction, so that the airflow injected from the plurality of injection ports is in a spiral shape, and the high-temperature flue gas returning after entrainment is in a spiral shape, which is beneficial to extending the returning path of the high-temperature flue gas, enhancing the circulating and returning effect of the flue gas in the second combustion chamber 102, and realizing good heat preservation in the second combustion chamber 102.

In view of the above, the burner further includes a gas distribution structure 145, and the mixing passage communicates with the plurality of injection ports in a one-to-one correspondence via the gas distribution structure 145. Synchronous and homogeneous jet flow of a plurality of jet ports is realized.

Further, in one embodiment, the gas distribution chamber includes a first chamber 145a and a second chamber 145b which are communicated in sequence, the gas inlet of the first chamber 145a is communicated with the premixer 140, and the gas outlet of the second chamber 145b is communicated with the second combustion chamber 102; wherein the second chamber 145b is disposed in a diverging manner along the gas flowing direction. It will be appreciated that the smaller flow area of the first chamber 145a than the second chamber 145b helps to increase the flow rate of the gas stream from the premixer 140 into the distribution chamber; the second chamber 145b is the gradually-expanding setting along the gas flow direction, and the flow area of the second chamber 145b is gradually increased along the gas flow direction, so that the flow rate of the mixed gas in the second chamber 145b is gradually gentle and gradually dispersed, and the mixed gas sprayed by each nozzle is uniform and stable.

Among the plurality of injection ports, a plurality of injection ports may form an injection port group, and at least two injection port groups are disposed on opposite sides of the second combustion chamber 102, wherein, taking the example that two injection port groups are disposed, two gas distribution structures 145 are disposed corresponding to the opposite sides of the second combustion chamber 102; the pre-mixer 140 is connected with the two gas distribution structures 145 through a connecting pipe, so that the purpose that the same pre-mixer 140 simultaneously provides mixed gas for the two gas distribution structures 145 synchronously is achieved, and the mixed gas ejected by each injection port is ensured to be approximately the same.

In an embodiment, the air intake assembly 120 includes a gas conduit 121 and a gas proportional valve 122, the gas conduit 121 is respectively communicated with the first combustion chamber 101 and the gas flow channel 143, and the gas proportional valve 122 is used for respectively adjusting gas flow rates of the first combustion chamber 101 and the gas flow channel 143. The gas inlet of the gas pipeline 121 is used for communicating with a gas source, the gas outlet of the gas pipeline 121 is respectively communicated with the first combustion chamber 101 and the gas flow channel 143, and the gas proportional valve 122 can adjust the respective gas flow rates of the first combustion chamber 101 and the gas flow channel 143, so that the gas flow rates in the first combustion chamber 101 and the gas flow channel 143 can be adjusted, and the ratio of gas to air can be adjusted and controlled.

In view of the above, the atmospheric burner 110 includes a combustion unit 111 having an air flow channel 112, a combustion module 113 provided at an air outlet of the air flow channel 112, and an ignition device 114 provided in the first combustion chamber 101 and configured to ignite the combustion module 113. The combustion assembly 113 is disposed at the air outlet of the air flow channel 112, so that after the air and the gas are substantially mixed in the air flow channel 112, the air and the gas are ignited by the ignition device 114 at the combustion assembly 113, and continuous and uniform combustion is realized.

The specific expression of the combustion assembly 113 is not limited in this design, and in an embodiment, the combustion assembly 113 includes a plate-shaped body covering the air outlet of the air flow channel 112, and a plurality of air vents penetrating along the thickness direction of the plate-shaped body. A plurality of vents can pass through mist to realize the evenly distributed of mist on platelike body face, thereby be favorable to mist's even combustion.

In one embodiment, the gas flow channel 112 is curved along the flowing direction of the mixed gas. The curved gas flow channel 112 helps to extend the length of the flow path of the mixed gas as much as possible in the limited space inside the housing of the combustion unit 111, thereby promoting sufficient mixing of the mixed gas, and making the mixed gas flow to the combustion assembly 113 for more sufficient combustion.

In one embodiment, the airflow passage 112 has an intake passage section 112a near an intake port of the airflow passage 112; the gas inlet passage section 112a is arranged in a way of necking and flaring along the flowing direction of the mixed gas. Specifically, the aperture of the air inlet passage section 112a is larger, which is helpful for increasing the flow rate of the gas, so that more gas can enter the air flow passage 112 more quickly; then, the cross-sectional area of the air inlet passage section 112a is gradually reduced, so that the fuel gas and the air are gathered together in a concentrated manner, and the fuel gas and the air are mixed quickly to form mixed gas; finally, the cross-sectional area of the gas inlet passage section 112a is gradually increased, which helps to gradually reduce the flow rate of the mixed gas, so that the state of the mixed gas is gradually gentle, and sufficient time can be reserved for the mixed gas to be fully mixed.

In an embodiment, a plurality of the combustion units 111 are arranged in the first combustion chamber 101 at intervals side by side; the air intake assembly 120 includes a gas pipe 121 and a gas distributing rod 123, and the gas pipe 121 is communicated with the plurality of gas flow channels 112 of the plurality of combustion units 111 through the gas distributing rod 123 in a one-to-one correspondence manner. Through the arrangement of the gas distributing rod 123, the same gas pipeline 121 can simultaneously provide approximately equivalent gas for the plurality of the combustion units 111, so that the combustion effects of the plurality of the combustion units 111 are basically the same and consistent.

In an embodiment, the burner further includes a control device and a flame sensing device 150, wherein the control device is electrically connected to the flame sensing device 150 and the blowing assembly 130, so as to control the operation of the blowing assembly 130 when the flame sensing device 150 senses that the combustion body is ignited. The flame sensing device 150 is used for detecting the flame of the burning subject to determine whether the atmospheric burner 110 is in a burning state. The control device may be an independent control unit provided independently of the control system unique to the gas plant, or may be a simple modification of the control system unique to the gas plant. When the air intake assembly 120 is used for introducing gas into the atmospheric burner 110, the gas entrains partial primary air, so that the atmospheric burner 110 is ignited to generate combustion flame; flame induction system 150 sends signal to controlling means when sensing the burning flame, and controlling means control air blast subassembly 130 work for under air blast subassembly 130's effect, in time mend secondary air, realize atmospheric burner 110's continuous burning, realize that high temperature air preheats.

In addition, the utility model also provides a gas device, which can be a gas water heater or a gas wall-mounted furnace, and comprises a heat exchanger 200 and the burner as described above, and of course, the gas device also comprises a main structure, wherein a heat exchange chamber and a smoke outlet communicated with the heat exchanger 200 are arranged in the main structure, the heat exchanger 200 is arranged in the heat exchange, the burner is provided with a smoke outlet, and the smoke outlet of the burner is communicated with the heat exchange chamber. The heat exchanger 200 is connected to an external water source, such as tap water, and the high-temperature flue gas entering the heat exchange chamber through the flue gas outlet of the burner carries enough heat to continuously exchange heat with the water in the heat exchanger 200, so that the temperature of the water is increased to be required, and hot water is prepared.

It should be noted that, the detailed structure of the burner in the gas appliance may refer to the above-mentioned embodiment of the burner, and is not described herein again; because the burner is used in the gas equipment, the embodiment of the gas equipment comprises all technical schemes of all embodiments of the burner, and the achieved technical effects are completely the same, which are not described again.

Claims

1. A burner, comprising:

the gas inlet assembly is used for connecting gas to the first combustion chamber;

the air blowing assembly is arranged on one side of the first combustion chamber, which is far away from the second combustion chamber, and is used for blowing air into the first combustion chamber; and the number of the first and second groups,

2. The burner of claim 1, wherein the combustion body comprises:

3. The burner of claim 1, wherein the premixer includes a casing and a blower, the casing is formed with an air intake duct, a gas flow duct, and a mixing chamber, an air inlet of the mixing chamber is communicated with the air intake duct and the gas flow duct, respectively, and an air outlet of the mixing chamber is communicated with the second combustion chamber;

the fan is arranged on the air inlet duct.

4. The burner of claim 3, wherein a plurality of injection ports are arranged at intervals on the side of the second combustion chamber;

5. The burner of claim 4, wherein the gas distribution structure is provided with a gas distribution cavity, the gas distribution cavity comprises a first chamber and a second chamber which are communicated in sequence, the gas inlet of the first chamber is communicated with the mixing cavity, and the gas outlet of the second chamber is communicated with the second combustion chamber;

6. The burner of claim 5, wherein there are two of said gas distribution structures corresponding to opposite sides of said second combustion chamber;

7. The burner of claim 3, wherein the intake assembly includes a gas conduit in communication with the first combustion chamber and the gas flow passage, respectively, and a gas proportional valve for regulating gas flow to the first combustion chamber and the gas flow passage, respectively.

8. The burner of claim 2, wherein the atmospheric burner comprises a combustion unit formed with an air flow channel, a combustion assembly disposed at an air outlet of the air flow channel, and an ignition device disposed in the first combustion chamber for igniting the air intake assembly.

9. The burner of claim 8, wherein the gas flow channel is curved in a direction of flow of the mixture gas.

10. The burner of claim 8, wherein the airflow passage has an intake passage section proximate to an intake port of the airflow passage;

11. The burner of claim 8, wherein a plurality of said combustion units are arranged in said first combustion chamber at intervals side by side;

12. The burner of claim 1, further comprising a control device and a flame sensing device, wherein the control device is electrically connected to the flame sensing device and the blower assembly to control the blower assembly to operate when the flame sensing device senses the ignition of the combustion body.

13. A gas-fired appliance comprising a heat exchanger and a burner as claimed in any one of claims 1 to 12, the heat exchanger producing hot water from heat generated by the burner.

14. The gas appliance of claim 13, wherein the gas appliance comprises a gas water heater or a gas wall-hanging stove.