Combustor and gas water heater

Abstract

The application discloses a burner and a gas water heater. The burner comprises a shell, a preheating burner, an injector and a flow guide. The shell forms a first combustion chamber and a second combustion chamber. The preheating burner is used for connecting gas and air and heating to a preset target temperature, and then providing the second combustion chamber. The injector is used for injecting air or gas or air-fuel mixture into the second combustion chamber, so that a high-temperature air combustion reaction is carried out in the second combustion chamber to form high-temperature flue gas. The flow guide defines a flow guide cavity and a flue gas passage, so that the high-temperature flue gas circulates and flows back in the flow guide cavity and is discharged through the flue gas passage. In the application, the flow guide makes at least part of the high-temperature flue gas circulate and flow back in the flow guide cavity, so that the second combustion chamber can be heat-insulated, and the flue gas in the second combustion chamber can continuously circulate at the preset target temperature, thereby helping to reduce the power requirement of the preheating burner, reduce the combustion burden of the preheating burner and reduce the cost.

Description

Technical Field

[0001] This invention relates to the field of water heater combustion technology, and particularly to a burner and a gas water heater. Background Technology

[0002] High-temperature air combustion (also known as mild and deep low-oxygen dilution combustion) is a novel combustion method. Compared to conventional combustion, under high-temperature air combustion conditions, fuel pyrolysis is suppressed, flame thickness increases, and the flame front disappears. This results in a highly uniform temperature throughout the furnace, significantly reducing NOx and CO emissions. Summary of the Invention

[0003] To apply high-temperature air combustion technology to daily life, a burner is proposed. This burner first preheats the air at high temperature in the combustion chamber using a preheating burner. Combustion is then achieved by injecting a stream of air and / or fuel gas into the combustion chamber through an injector, which entrains the high-temperature flue gas inside the combustion chamber. However, relying solely on the preheating burner to preheat the air results in a large proportion of the preheating burner's power distribution, leading to higher costs.

[0004] This invention provides a burner and a gas water heater, aiming to solve the problem of the large power distribution ratio of the preheating burner in existing burners.

[0005] To achieve the above objectives, the present invention provides a burner comprising:

[0006] The casing has a first combustion chamber and a second combustion chamber connected in sequence.

[0007] A preheating burner, located in the first combustion chamber, is used to receive fuel gas and air and heat them to a preset target temperature before supplying them to the second combustion chamber;

[0008] An injector is used to inject air, fuel gas, or an air-fuel mixture into the second combustion chamber to interact with the flue gas heated to a preset target temperature supplied to the first combustion chamber, thereby causing a high-temperature air combustion reaction in the second combustion chamber and forming high-temperature flue gas; and,

[0009] A flow guide defines a flow guide cavity and a flue gas passage that are interconnected within the second combustion chamber, so that the high-temperature flue gas can circulate back within the flow guide cavity and be discharged through the flue gas passage.

[0010] In one embodiment, the connection between the first combustion chamber and the second combustion chamber constitutes a flue gas outlet;

[0011] The guide member includes a cavity shell forming the guide cavity, the end of the cavity shell facing the flue gas inlet is open, and the flue gas passage is formed between the outer wall of the cavity shell and the inner wall of the second combustion chamber.

[0012] In one embodiment, the cavity shell includes two shell plates, which are arranged at a relative interval to enclose and form the flow guiding cavity;

[0013] The flue gas passage is provided in two corresponding to the two shell plates.

[0014] In one embodiment, the cavity shell is cylindrically disposed in the middle of the second combustion chamber, and the end of the cavity shell away from the flue gas inlet is closed.

[0015] The flue gas passage is arranged in a ring around the outer periphery of the cavity shell.

[0016] In one embodiment, the flow guide further includes a flue shell disposed within the flow guide cavity, the flue shell being disposed through the opening in both directions.

[0017] In one embodiment, the flue shell is cylindrical and located in the middle of the flow guiding cavity.

[0018] In one embodiment, the channel opening near the opening of the flue shell is a smoke inlet, and the smoke inlet is flared in the direction near the opening; and / or,

[0019] The passageway of the flue shell away from the opening is the smoke outlet, and the smoke outlet is flared out in the direction away from the opening.

[0020] In one embodiment, the opening of the cavity shell is narrowed in the direction close to the flue gas inlet.

[0021] In one embodiment, the cavity shell has a cavity bottom plate located away from the flue gas inlet;

[0022] The cavity bottom plate is inclined from its periphery to its center, gradually moving away from the flue gas inlet.

[0023] In one embodiment, the burner further includes a premixer for receiving and premixing fuel gas and air, and for supplying the mixed gas to the first combustion chamber.

[0024] In one embodiment, the injector includes a gas distribution rod, the air inlet of which is connected to the premixer, and the gas distribution rod has a plurality of nozzles, which are spaced apart circumferentially along the second combustion chamber and are in communication with the second combustion chamber.

[0025] In one embodiment, the premixer includes a housing, a gas regulating valve, and a fan. The housing forms a gas passage, an air passage, and a mixing passage. The air inlet of the mixing passage is connected to the gas passage and the air passage, respectively.

[0026] The gas regulating valve is located in the gas passage to regulate the gas intake volume of the gas passage, and the fan is located in the mixing passage.

[0027] In one embodiment, the preheating burner includes a combustion assembly and an ignition device for igniting the combustion assembly.

[0028] In one embodiment, the combustion assembly includes a metal fiber mesh, the middle portion of which is recessed along the gas flow direction at its location.

[0029] In addition, to achieve the above objectives, the present invention also provides a gas water heater, including a main body, a heat exchanger and a burner as described above, wherein a heat exchange chamber is provided inside the main body and the heat exchanger is disposed inside the heat exchange chamber.

[0030] In the technical solution provided by this invention, the preheating burner provides the second combustion chamber with flue gas heated to a preset target temperature; the injector injects air, gas, or an air-fuel mixture to entrain the flue gas and achieve high-temperature air combustion; the guide member defines the guide cavity and flue gas passage, so that at least part of the high-temperature flue gas circulates back in the guide cavity, which can keep the second combustion chamber warm and ensure that the flue gas at the preset target temperature is continuously circulated in the second combustion chamber, thereby helping to reduce the power requirement of the preheating burner, reduce the combustion burden of the preheating burner, and reduce costs. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0032] Figure 1 A schematic diagram of the structure of an embodiment of the gas water heater provided by the present invention;

[0033] Figure 2 for Figure 1 A partial cross-sectional view of a gas water heater;

[0034] Figure 3 for Figure 2 A magnified structural diagram of point A in the middle.

[0035] Explanation of icon numbers:

[0036]

[0037]

[0038] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0042] High-temperature air combustion (also known as mild and deep low-oxygen dilution combustion) is a novel combustion method. Compared to conventional combustion, under high-temperature air combustion conditions, fuel pyrolysis is suppressed, flame thickness increases, and the flame front disappears. This results in a highly uniform temperature throughout the furnace, significantly reducing NOx and CO emissions.

[0043] To apply high-temperature air combustion technology to daily life, a burner is proposed. This burner first preheats the air at high temperature in the combustion chamber using a preheating burner. Combustion is then achieved by injecting a stream of air and / or fuel gas into the combustion chamber through an injector, which entrains the high-temperature flue gas inside the combustion chamber. However, relying solely on the preheating burner to preheat the air results in a large proportion of the preheating burner's power distribution, leading to higher costs.

[0044] This invention provides a burner that is applied to gas water heaters and related products and equipment, including gas wall-hung boilers, which use gas combustion to generate high-temperature hot water for home bathing and heating. For ease of understanding, the following example is applied to gas water heaters. Figures 1 to 3 An embodiment of the burner provided by the present invention is applied to a gas water heater.

[0045] Please see Figures 1 to 3 The burner provided by the present invention includes a housing 100, a preheating burner 200, an injector 300, and a flow guide 400. The housing 100 forms a first combustion chamber 110 and a second combustion chamber 120 connected in sequence. The preheating burner 200 is disposed in the first combustion chamber 110 and is used to supply gas and air, heat them to a preset target temperature, and then supply them to the second combustion chamber 120. The injector 300 is used to inject air, gas, or a mixture of air and gas into the second combustion chamber 120 to interact with the flue gas heated to the preset target temperature supplied by the first combustion chamber 110, causing a high-temperature air combustion reaction to occur in the second combustion chamber 120 and forming high-temperature flue gas. The flow guide 400 defines a flow guide cavity 401 and a flue gas passage 402 connected to each other within the second combustion chamber 120, allowing the high-temperature flue gas to circulate back within the flow guide cavity 401 and be discharged through the flue gas passage 402.

[0046] In the technical solution provided by this invention, the preheating burner 200 provides the second combustion chamber 120 with flue gas heated to a preset target temperature; the injector 300 injects air or gas or a mixture of air and gas, entraining the flue gas to achieve high-temperature air combustion; the guide member 400 defines the guide cavity 401 and the flue gas passage 402, so that at least part of the high-temperature flue gas circulates back in the guide cavity 401, which can keep the second combustion chamber 120 warm and ensure that the flue gas at the preset target temperature is continuously circulated in the second combustion chamber 120, thereby helping to reduce the power requirement of the preheating burner 200, reduce the combustion burden of the preheating burner 200, and reduce costs.

[0047] In this embodiment, the burner generates high-temperature flue gas through combustion, and the burner can produce hot water by directly expelling the high-temperature flue gas and exchanging heat with the heat exchanger; or, in other embodiments, at least a portion of the shell 100 can be made of a thermally conductive material, so the burner can also produce hot water by contacting the heat exchanger for heat exchange.

[0048] This design does not limit the specific form of the housing 100. For example, the shape of the housing 100 can be roughly cylindrical, prismatic, etc.; the cross-sectional shape of the housing 100 can be circular, elliptical, polygonal, or other irregular shapes; the shapes of the first combustion chamber 110 and the second combustion chamber 120 can be set to match the shape of the housing 100 at their respective locations.

[0049] Of course, the specific shapes of the first combustion chamber 110 and the second combustion chamber 120 can be adjusted according to actual needs. In one embodiment, the second combustion chamber 120 includes two chambers connected in sequence in a direction away from the first combustion chamber 110. The connection between the two chambers is in a direction away from the first combustion chamber 110, and the flow area is gradually increased, so that the flow area of ​​the chamber away from the first combustion chamber 110 is greater than the flow area of ​​the chamber close to the first combustion chamber 110.

[0050] The first combustion chamber 110 and the second combustion chamber 120 can each be formed by two shell structures of the housing 100, and these two shell structures can be detachably assembled. There are various ways to assemble the two shell structures, such as screw fixing, snap fixing, or adhesive fixing. Of course, the first combustion chamber 110 and the second combustion chamber 120 can also be formed in a separate area within a single shell structure.

[0051] This design does not restrict the orientation of the first combustion chamber 110 and the second combustion chamber 120. When the burner is equipped with a fan (such as the fan 530 in the attached figure), the flue gas is affected by the intake action of the fan 530. In specific applications, the second combustion chamber 120 can be set downstream of the first combustion chamber 110. That is, the air-fuel mixture is preheated by the first combustion chamber 110 before entering the second combustion chamber 120 for high-temperature air combustion. When the fan 530 is set above for inverted combustion, the first combustion chamber 110 is set above the second combustion chamber 120. When the fan 530 is set below, the first combustion chamber 110 is set below the second combustion chamber 120. To facilitate flue gas removal and further improve the heat exchange efficiency between the flue gas from the burner and the heat exchanger, the downstream section of the second combustion chamber 120 can be set as an open structure to form a larger flue gas outlet. The heat exchanger can be set at least partially close to the injection port of the first combustion chamber 110 or the second combustion chamber 120 so that more flue gas can exchange heat with the heat exchanger.

[0052] The main characteristics of high-temperature air combustion are: the chemical reaction needs to occur in a high-temperature, low-oxygen environment; the reactant temperature is higher than its auto-ignition temperature; and the maximum temperature rise during combustion is lower than its auto-ignition temperature. The oxygen volume fraction is diluted to an extremely low concentration by the combustion products. Compared to conventional combustion, under this combustion state, fuel pyrolysis is suppressed, the flame thickness increases, and the flame front disappears, resulting in a very uniform temperature throughout the furnace, a low peak combustion temperature, minimal noise, and a significant reduction in NOx and CO emissions. However, achieving high-temperature air combustion requires certain conditions: the oxygen concentration in most areas of the furnace needs to be below a certain value, generally below 5%–10%, to ensure complete combustion and uniform combustion of the fuel, and the temperature must be higher than the fuel's auto-ignition point to maintain auto-ignition.

[0053] The preheating burner 200 can be an electric preheater or a regenerative preheater. In this embodiment, the preheating burner 200 is a gas-fired preheater, which obtains high-temperature flue gas at the target temperature by mixing and burning a certain proportion of gas and air. The preheating burner 200 is installed in the first combustion chamber 110, and can be specifically installed at the gas inlet of the first combustion chamber 110. The preheating burner 200 ignites the gas mixture in the first combustion chamber 110, causing the gas mixture to burn and forming a preset high temperature in the area, thereby achieving high-temperature preheating and forming high-temperature flue gas.

[0054] The injector 300 injects fuel gas, air, or a mixture of air and fuel gas into the second combustion chamber 120. The fuel gas is ignited by the high-temperature gas and continues to burn in the second combustion chamber 120, forming an injection combustion zone. Furthermore, the fuel gas / or air injected at a preset speed, in combination with the aforementioned high-temperature flue gas, creates an entrainment effect in the second combustion chamber 120, forming a flue gas recirculation zone. This allows some of the high-temperature flue gas (exhaust gas rich in N2 and CO2) to circulate and dilute the reactants within the second combustion chamber 120, thereby fully diluting the injected fuel gas and air to form a lower oxygen concentration, reducing the combustion reaction rate, and maintaining a higher temperature within the second combustion chamber 120. This ensures that the temperature within the second combustion chamber 120 is higher than the auto-ignition point of the fuel, achieving auto-ignition and thus realizing high-temperature air combustion.

[0055] By preheating the air at high temperature and using a high-speed jet to entrain and dilute the high-temperature flue gas, not only can the gas be fully combusted, reducing pollutant emissions, but the combustion in the second combustion chamber 120 is also more uniform, preventing the problem of excessive local combustion and noise.

[0056] As mentioned above, the target temperature for high-temperature preheated air should not be too low, and should ideally not fall below 600 degrees Celsius. Generally, controlling the temperature between 600 and 1200 degrees Celsius ensures good automatic combustion when the high-temperature gas comes into contact with the airflow ejected from the injector 300, eliminating the need for ignition. There are several ways to achieve high-temperature preheated air, such as controlling the heating time, controlling the gas-to-air ratio, providing insulation, and increasing the residence time of the high-temperature gas in the second combustion chamber 120.

[0057] A flow guide 400 is disposed within the second combustion chamber 120, defining a flow guide cavity 401 and a flue gas passage 402 within the second combustion chamber 120. The flow guide cavity 401 and the flue gas passage 402 are respectively connected. After high-temperature preheating and injection entrainment, part of the high-temperature flue gas can be directly discharged through the flue gas passage 402 to exchange heat with the heat exchanger, while the other part continuously circulates back within the flow guide cavity 401, which helps to maintain a higher temperature within the second combustion chamber 120, ensuring that the temperature within the second combustion chamber 120 is higher than the auto-ignition point of the fuel. When the high-temperature flue gas within the second combustion chamber 120 is stable and continuously circulates back, the flue gas within the second combustion chamber 120 is sufficient to meet the preset target temperature, which helps to reduce the combustion power requirements of the preheating burner 200, thereby achieving the purpose of energy saving, consumption reduction, and cost reduction.

[0058] There are various specific solutions for the guide member 400 to achieve the above-mentioned objectives. In one embodiment, the connection between the first combustion chamber 110 and the second combustion chamber 120 constitutes a flue gas outlet. The guide member 400 includes a cavity shell 410 forming the guide cavity 401. The end of the cavity shell 410 facing the flue gas outlet has an opening 411, and the outer wall of the cavity shell 410 and the inner wall of the second combustion chamber 120 form the flue gas passage 402. The opening 411 of the cavity shell 410 is spaced apart from and connected to the flue gas outlet, so that the high-temperature flue gas discharged through the flue gas outlet can directly enter the guide cavity 401 and the flue gas passage 402 through the gap between the opening 411 and the flue gas outlet.

[0059] The opening 411 forms the air inlet of the guide cavity 401. In one embodiment, the flow area of ​​the air inlet of the guide cavity 401 can be further set to be larger than the flow area of ​​the air inlet of the flue gas passage 402, so that a larger portion of the high-temperature flue gas discharged through the flue gas passage enters the guide cavity 401 for circulation and recirculation.

[0060] There are several specific designs for the housing 410 to define the guide cavity 401 and the flue gas passage 402 within the second combustion chamber 120:

[0061] In one embodiment, the cavity shell 410 includes two shell plates, which are arranged at a relative interval to form the flow guiding cavity 401; the flue gas passage 402 is formed between the outer wall of the two shell plates and the inner wall of the heat exchanger.

[0062] When the two shell plates extend to both sides and abut against the two side walls of the second combustion chamber 120, the two shell plates 410 and the two side walls of the second combustion chamber 120 together form a flow guide cavity 401; the remaining part of the second combustion chamber 120, excluding the flow guide cavity 401, forms a flue gas passage 402, which helps to simplify the structure of the cavity shell 410.

[0063] The two shell plates can also be configured to be spaced apart from the side wall of the second combustion chamber 120 (that is, the inner wall of the cavity surrounding the heat exchanger), that is, to form a flow guide cavity 401 between the outer periphery of the flow guide cavity 410 and the heat exchange tube.

[0064] The connection method between the two shell plates and the side wall of the second combustion chamber 120 is not limited. It can be integrally formed or fixed by means of bonding, adsorption, fastening, etc. The specific shape of the two shell plates is not limited. At least one of the two shell plates can be a straight plate, an arc plate, or a folded plate formed by at least one bending.

[0065] The end of the guide cavity 401 away from the opening 411 is the bottom of the guide cavity 401. The bottom of the guide cavity 401 can be directly connected to the flue gas passage 402. However, in order to enhance the circulation and backflow of high-temperature flue gas in the guide cavity 401, the bottom of the guide cavity 401 is set to be closed, or some through holes are set at the bottom of the guide cavity 401 to communicate with the flue gas passage 402.

[0066] In another embodiment, the cavity shell 410 is cylindrically disposed in the middle of the second combustion chamber 120, and the end of the cavity shell 410 away from the flue gas inlet is closed; the flue gas passage 402 is annularly disposed around the outer periphery of the cavity shell 410.

[0067] When the cavity shell 410 is cylindrical, it can directly enclose the flow guide cavity 401. Based on this, the cavity shell 410 can be detachably assembled with the inner wall of the second combustion chamber 120, so that the cavity shell 410 of different shapes and sizes can be disassembled and replaced as needed.

[0068] The flue gas passage 402 is arranged in a ring around the outer periphery of the cavity shell 410, which helps the high-temperature flue gas to be evenly distributed and circulated in the second combustion chamber 120.

[0069] In one embodiment, the flow guide 400 further includes a flue shell 420 disposed within the flow guide cavity 401, the flue shell 420 being disposed through-through in the direction approaching and away from the opening 411. An inner channel is formed at the through-through location of the flue shell 420, and an outer channel is defined by the outer wall of the flue shell 420 and the inner wall of the cavity shell 410. The inner channel and the two outer channels on both sides together constitute the flow guide cavity 401. Each outer channel communicates with the inner channel and defines an annular channel, which allows for continuous recirculation of high-temperature flue gas.

[0070] Similarly to the cavity shell 410 described above, in one embodiment, the flue shell 420 can also be composed of two single plates arranged at intervals. The two single plates and the cavity shell 410 together define an inner channel and two outer channels. In this case, the two outer channels are separated by the inner channel. Alternatively, in another embodiment, the flue shell 420 is cylindrical and located in the middle of the guide cavity 401. In this case, the two outer channels are interconnected to form an annular structure surrounding the inner channel, which is equivalent to forming multiple annular channels in the circumferential direction of the inner channel, thereby enhancing the circulation and recirculation of high-temperature flue gas in the guide cavity 401.

[0071] The direction of the high-temperature flue gas recirculation within the annular channel is not limited; it can flow from the inner channel to the outer channel or from the outer channel to the inner channel. In one embodiment, the channel opening of the flue shell 420 near the opening 411 is the flue gas inlet 421. The flue gas inlet 421 is flared in the direction near the opening 411. This flared design creates a larger flow area, allowing more high-temperature flue gas to enter. At the same time, the flared design forms a guide surface, directing the high-temperature flue gas to the inner channel of the flue shell 420, so that the high-temperature flue gas flows from the inner channel to the outer channel, forming a circulation.

[0072] And / or, in one embodiment, the channel opening of the flue shell 420 away from the opening 411 is a smoke outlet 422, and the smoke outlet 422 is flared out in the direction away from the opening 411. The flared design of the smoke outlet 422 can form a larger flow area, allowing more high-temperature flue gas to flow out. At the same time, the flared design can form a guide surface, guiding the high-temperature flue gas from the inner channel to the outer channel, forming a circulation.

[0073] Furthermore, in one embodiment, the opening 411 of the cavity shell 410 is narrowed in the direction near the flue gas inlet, which can guide the high-temperature flue gas in the outer channel to the inner channel, which is beneficial to the recirculation of the high-temperature flue gas.

[0074] In addition, in one embodiment, the cavity shell 410 has a cavity bottom plate 412 that is away from the flue gas inlet; the cavity bottom plate 412 is inclined from its periphery to its center, gradually moving away from the flue gas inlet, which can guide the high-temperature flue gas in the inner channel to the outer channel, and is also conducive to the recirculation of high-temperature flue gas.

[0075] In addition, the preheating burner 200 can be directly connected to gas and air and perform combustion; or, the burner may also include a premixer 500, which is used to connect gas and air and perform premixing, and to provide mixed gas to the first combustion chamber 110.

[0076] It is understood that the premixer 500 generally includes a housing 510, which forms a gas passage 511, an air passage 512, and a mixing passage 513. The air inlet of the mixing passage 513 is connected to the gas passage 511 and the air passage 512 respectively, and the air outlet of the mixing passage 513 is connected to a plurality of combustion chambers respectively. The gas passage 511 is used to receive external gas, the air passage 512 is used to receive external air, and the received gas and air are mixed in the mixing passage 513.

[0077] In the mixed gas formed by premixing in the premixer 500, the ratio of fuel gas to air needs to be set within a suitable range to ensure that the burner can achieve full and efficient combustion in the mixed gas environment.

[0078] Based on this, in a further embodiment, the premixer 500 may be equipped with proportional valves at the gas passage 511 and / or the air passage 512. For distinction, the proportional valve at the gas passage 511 can be defined as a gas proportional valve, and the proportional valve at the air passage 512 as an air proportional valve. By operating the gas proportional valve and / or the air proportional valve, the gas intake and / or air intake in the premixer 500 can be adjusted, thereby obtaining the required proportion of mixed gas. In this embodiment, a gas proportional valve is provided at the gas passage 511, and the gas intake can be adjusted accordingly by adjusting the opening degree of the gas proportional valve.

[0079] Furthermore, the premixer 500 may also be equipped with a fan 530, which drives the airflow of gas and / or air within the premixer 500, allowing the airflow to enter each combustion chamber approximately in the desired direction and at the desired speed. In specific applications, the fan 530 may be located in the air passage 512 to accelerate airflow, cooperating with the gas proportional valve to achieve separate control of the air intake and gas intake; alternatively, the fan 530 may be located in the mixing passage 513, which not only drives the flow of gas, air, and the mixed gas, but also allows the gas and air to be dispersed by the rotating blades of the fan 530 for more thorough mixing.

[0080] In one embodiment, the injector 300 includes a gas distribution rod 310, the air inlet of which is connected to the premixer 500. The gas distribution rod 310 has multiple nozzles 311, which are spaced apart circumferentially along and connected to the corresponding second combustion chamber 120. When the injector 300 further includes multiple nozzles 311, the multiple nozzles 311 of the gas distribution rod 310 are arranged in a one-to-one correspondence. The gas distribution rod 310 directly obtains the mixed gas from the premixer 500. The arrangement of the gas distribution rod 310 provides a balanced and stable mixed gas to the multiple nozzles 311 in each second combustion chamber 120, thereby achieving a uniform and consistent entrainment effect throughout the circumference of the second combustion chamber 120.

[0081] Next, in one embodiment, the preheating burner 200 includes a combustion component 210 and an ignition device 220 for igniting the combustion component 210. When the mixed gas passes through and accumulates to a certain extent at the combustion component 210, the mixed gas at the combustion component 210 is ignited by operating the ignition device 220, thereby achieving the purpose of preheating the air at high temperature.

[0082] The specific selection of the combustion component 210 is not limited in this design. For example, in one embodiment, the combustion component 210 includes a plate-shaped body, and multiple gas passage holes are provided in the thickness direction of the plate-shaped body for the mixed gas to pass through, which is beneficial to the uniform combustion of the mixed gas.

[0083] Please see Figures 1 to 3In one embodiment, the combustion assembly 210 includes a metal fiber mesh 211, the middle portion of which is recessed along the gas flow direction at its location. The metal fiber mesh 211 is generally plate-shaped and covers the air inlet of the first combustion chamber 110; the mesh of the metal fiber mesh 211 forms the aforementioned plurality of air passage holes; the middle portion of the metal fiber mesh 211 is recessed along the gas flow direction at its location, that is, the metal fiber mesh 211 gradually protrudes towards the second combustion chamber 120 from its edge to its center, so as to accumulate a certain amount of mixed gas and achieve continuous and stable combustion of the combustion assembly 210.

[0084] Furthermore, this invention also provides a gas water heater, specifically a gas wall-hung boiler. The gas water heater includes a heat exchanger and a burner as described above. It also includes a main body containing a heat exchange chamber and a flue gas outlet connected to the heat exchanger. The heat exchanger is located within the heat exchange chamber, and the burner has a flue gas outlet, for example, a flue gas outlet in a second combustion chamber 120 located away from the first combustion chamber 110, and this outlet is connected to the heat exchanger. The heat exchanger is connected to an external water source, such as tap water. The high-temperature flue gas entering the heat exchange chamber through the burner's flue gas outlet carries sufficient heat to continuously heat the water within the heat exchanger, raising the water temperature to the desired level to produce hot water.

[0085] The burner can be installed independently of the main body of the gas wall-hung boiler, and can be connected and fixed to the main body of the gas wall-hung boiler by means of screw fixing, snap fixing, etc., which facilitates disassembly and replacement at any time; of course, the burner can also be an integral component of the main body of the gas wall-hung boiler, integrally formed with the main body, which is easy to process and makes the overall structure more compact.

[0086] The combustion chamber and heat exchange chamber can be set up independently. After sufficient combustion is achieved in the combustion chamber to produce enough combustion flue gas, the combustion flue gas is discharged into the heat exchange chamber through the connection between the combustion chamber and the heat exchange chamber to achieve the purpose of heat exchange. Of course, the combustion chamber and heat exchange chamber can also be set up as one unit. The combustion chamber can constitute at least part of the heat exchange chamber, and at least part of the heat exchange tubes can be directly set in the combustion chamber to achieve better heat exchange effect.

[0087] In addition, since the high-temperature flue gas generated by the burner condenses and produces acidic condensate when it passes through the heat exchanger, it needs to be neutralized by acid and alkali before being discharged in order to meet emission standards. Therefore, the gas water heater also includes a condensate neutralizer, which is installed at the condensate outlet of the gas water heater.

[0088] It should be noted that the detailed structure of the burner in the gas water heater can be referred to the above-described burner embodiments, and will not be repeated here. Since the above-described burner is used in the gas water heater of the present invention, the embodiments of the gas water heater of the present invention include all the technical solutions of all the above-described burner embodiments, and the technical effects achieved are exactly the same, and will not be repeated here.

[0089] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A burner, characterized in that, include: The casing has a first combustion chamber and a second combustion chamber connected in sequence. A preheating burner, located in the first combustion chamber, is used to receive fuel gas and air and heat them to a preset target temperature before supplying them to the second combustion chamber; An injector is used to inject air, fuel gas, or an air-fuel mixture into the second combustion chamber to interact with the flue gas heated to a preset target temperature delivered to the first combustion chamber, thereby causing a high-temperature air combustion reaction to occur in the second combustion chamber and forming high-temperature flue gas. A flow guide is provided, which defines a flow guide cavity and a flue gas passage that are interconnected in the second combustion chamber, so that the high-temperature flue gas can circulate back in the flow guide cavity and be discharged through the flue gas passage. The connection between the first combustion chamber and the second combustion chamber forms a flue gas outlet; The flow guide includes a cavity shell forming the flow guide cavity, the cavity shell being open at one end facing the flue gas inlet, and the flue gas passage being formed between the outer wall of the cavity shell and the inner wall of the second combustion chamber; The cavity shell is cylindrical and disposed in the middle of the second combustion chamber, with the end of the cavity shell away from the flue gas inlet being closed. The flue gas passage is arranged in a ring around the outer periphery of the cavity shell; The flow guide also includes a flue shell disposed within the flow guide cavity, the flue shell being disposed in a through manner in the direction approaching and away from the opening; The cavity shell has a cavity bottom plate that is away from the flue gas inlet; the cavity bottom plate is inclined from its periphery to its center away from the flue gas inlet.

2. The burner as claimed in claim 1, characterized in that, The cavity shell includes two shell plates, which are arranged at a relative interval to enclose and form the flow guiding cavity; The flue gas passage is provided in two corresponding to the two shell plates.

3. The burner as described in claim 1, characterized in that, The flue shell is cylindrical and located in the middle of the flow guiding cavity.

4. The burner as claimed in claim 1, characterized in that, The channel opening near the opening in the flue shell is a smoke inlet, and the smoke inlet is flared out in the direction near the opening; and / or, The passageway of the flue shell away from the opening is the smoke outlet, and the smoke outlet is flared out in the direction away from the opening.

5. The burner as claimed in claim 1, characterized in that, The opening of the cavity shell is narrowed in the direction near the flue gas inlet.

6. The burner as claimed in claim 1, characterized in that, The burner also includes a premixer for receiving and premixing fuel gas and air, and for supplying the mixed gas to the first combustion chamber.

7. The burner as claimed in claim 6, characterized in that, The injector includes a gas distribution rod, the air inlet of which is connected to the premixer, and the gas distribution rod has multiple nozzles, which are spaced apart circumferentially along the second combustion chamber and are connected to the second combustion chamber.

8. The burner as claimed in claim 6, characterized in that, The premixer includes a housing, a gas regulating valve, and a fan. The housing forms a gas passage, an air passage, and a mixing passage. The air inlet of the mixing passage is connected to the gas passage and the air passage, respectively. The gas regulating valve is located in the gas passage to regulate the gas intake volume of the gas passage, and the fan is located in the mixing passage.

9. The burner as claimed in claim 1, characterized in that, The preheating burner includes a combustion assembly and an ignition device for igniting the combustion assembly.

10. The burner as claimed in claim 9, characterized in that, The combustion assembly includes a metal fiber mesh, the middle of which is recessed along the gas flow direction at its location.

11. A gas water heater, characterized in that, It includes a main body, a heat exchanger, and a burner as described in any one of claims 1 to 10, wherein a heat exchange chamber is provided within the main body, and the heat exchanger is disposed within the heat exchange chamber.

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