Burners and gas water heaters

Abstract

The present invention discloses a burner and a gas water heater, wherein the burner comprises a shell and a preheating burner; a premixing chamber, an air preheating chamber and a combustion chamber which are connected in sequence are arranged in the shell, the premixing chamber has an air inlet for receiving air and gas, the air preheating chamber has an air outlet for air to flow into it, the combustion chamber has a smoke outlet and a gas outlet, the gas outlet is used to spray gas into the combustion chamber, so that a high-temperature air combustion reaction is carried out in the combustion chamber; the preheating burner is installed in the air preheating chamber, and the preheating burner is used to ignite the mixed gas discharged from the premixing chamber into the air preheating chamber, and heat the temperature in the air preheating chamber to a preset temperature. The burner of the present invention makes the combustion of the mixed gas in the preheating burner more complete, so that the emission of CO and NOX in the whole combustion process is greatly reduced.

Description

[0001] This application claims priority to Chinese patent application No. 201910992986.8, filed on October 17, 2019, and entitled “BURNER AND GAS WATER HEATER”, the entire text of which is hereby incorporated by reference. Technical Field

[0002] The invention relates to the technical field of high-temperature air combustion, and in particular to a burner and a gas water heater. Background Art

[0003] High temperature air combustion is called "mild and deep low oxygen dilution combustion", or gentle combustion for short. It is a new type of combustion method, also known as MILD combustion. The main characteristics of this combustion are: the chemical reaction mainly occurs in a high temperature and low oxygen environment, the reactant temperature is higher than its natural temperature, and the maximum temperature rise during the combustion process is lower than its auto-ignition temperature, and the oxygen volume fraction is diluted to an extremely low concentration by the combustion products. Compared with conventional combustion, in this combustion state, the pyrolysis of the fuel is suppressed, the flame thickness becomes thicker, and the flame front disappears, so that the temperature of the entire furnace is very uniform during this combustion, and the emissions of pollutants NOx and CO are greatly reduced.

[0004] Although high-temperature air combustion has many advantages as mentioned above, there is currently no professional burner to achieve the above high-temperature air combustion. In the related art, a premixing chamber is defined in the shell so that the gas and air are mixed in the premixing chamber and then sent to the preheating burner for combustion. Therefore, whether the mixed gas in the premixing chamber is mixed evenly determines whether it is completely burned in the preheating burner. Therefore, there is an urgent need for a burner that can achieve high-temperature air combustion and make the preheating burner burn completely.

[0005] The above contents are only used to assist in understanding the technical solution of the invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The main purpose of the present invention is to provide a burner, aiming to solve one or more of the above-mentioned technical problems.

[0007] To achieve the above-mentioned purpose, the burner proposed in the present invention includes a shell and a preheating burner;

[0008] The housing is provided with a premixing chamber, an air preheating chamber and a combustion chamber which are connected in sequence; the premixing chamber has an air inlet for receiving air and gas, the air preheating chamber has an air outlet for air to flow into it, the combustion chamber has a smoke outlet and a gas outlet, and the gas outlet is used to inject gas into the combustion chamber so that a high-temperature air combustion reaction is carried out in the combustion chamber; and

[0009] A preheating burner is installed in the air preheating chamber, and is used to ignite the mixed gas discharged from the premixing chamber into the air preheating chamber, and heat the temperature in the air preheating chamber to a preset temperature.

[0010] In one embodiment, the housing comprises an outer shell and a first cylinder disposed in the outer shell, wherein the combustion chamber is defined in the first cylinder;

[0011] A gas distribution chamber is defined between the first cylinder and the outer shell, the gas outlet is communicated with the gas distribution chamber, and the gas distribution chamber has a gas inlet.

[0012] In one embodiment, there are a plurality of gas outlets, and the plurality of gas outlets are opened on the peripheral wall surface of the first cylinder and are spaced apart along the circumference of the first cylinder.

[0013] In one embodiment, the shell further includes a second cylinder disposed in the outer shell, the air preheating chamber and the premixing chamber are defined in the second cylinder, an air distribution chamber is defined between the second cylinder and the outer shell, the air distribution chamber has an air inlet, and there are multiple air outlets, the multiple air outlets are opened on the peripheral wall surface of the second cylinder, and are arranged at intervals along the circumference of the second cylinder.

[0014] In one embodiment, the premixing chamber, the air preheating chamber, and the combustion chamber are arranged in sequence from bottom to top, the gas outlet is provided at the upper end of the first cylinder, and the gas flow direction of the gas outlet is downward or inclined downward.

[0015] In one embodiment, the burner further comprises a spiral assembly, wherein the spiral assembly is mounted on the premixing chamber so as to form a spiral channel in the premixing chamber, wherein the inlet of the spiral channel is connected to the air inlet, and the outlet of the spiral channel is connected to the air preheating chamber.

[0016] In one embodiment, the spiral assembly includes a center retaining ring and a spiral blade, the inner end of the spiral blade is connected to the center retaining ring, and the outer end of the spiral blade is connected to the inner wall surface of the premixing chamber, so that the spiral channel is defined between the spiral blade, the center retaining ring and the shell.

[0017] In one embodiment, the helix angle of the spiral blade is greater than or equal to 10 degrees and less than or equal to 45 degrees.

[0018] In one embodiment, a ratio of an extended height of the premixing chamber to an extended height of the spiral blade is greater than or equal to 1.2 and less than or equal to 2.

[0019] In one embodiment, the ratio of the inner diameter of the premixing chamber to the outer diameter of the central retaining ring is greater than or equal to 1.5 and less than or equal to 4.

[0020] In one embodiment, the bottom of the central retaining ring is spaced apart from the bottom wall of the premixing chamber.

[0021] In one embodiment, the spiral component includes a spiral coil, and the spiral channel is formed in the spiral coil.

[0022] The present invention also provides a gas water heater, comprising a main body, a heat exchanger and a burner, wherein the burner comprises a shell and a preheating burner;

[0023] The housing is provided with a premixing chamber, an air preheating chamber and a combustion chamber which are connected in sequence, and a high-temperature air combustion reaction is carried out in the combustion chamber; the premixing chamber has an air inlet for receiving air and gas, the air preheating chamber has an air outlet for air to flow into it, and the combustion chamber has a smoke outlet and a gas outlet, and the gas outlet is used to inject gas into the combustion chamber; and

[0024] A preheating burner is installed in the air preheating chamber, and the preheating burner is used to ignite the mixed gas discharged from the premixing chamber into the air preheating chamber;

[0025] Wherein, a heat exchange chamber and a smoke exhaust port connected to the heat exchange chamber are arranged in the main body, the heat exchanger is arranged in the heat exchange chamber, and the smoke outlet of the burner is connected to the heat exchange chamber.

[0026] The burner of the present invention is provided with a premixing chamber, an air preheating chamber and a combustion chamber which are connected in sequence in the shell, and the preheating burner ignites and burns the mixed gas, so as to realize high-temperature preheated air, and then the gas is sprayed through the gas outlet on the combustion chamber to cooperate to produce the entrainment effect, so that the high-temperature flue gas refluxes, on the one hand, to realize heat preservation, so that the gas in the combustion chamber can spontaneously ignite, and on the other hand, the air is diluted, so that the oxygen concentration is lower than a certain value, so as to realize uniform combustion, so that high-temperature air combustion occurs in the combustion chamber. The present invention realizes a specific and feasible burner with high-temperature air combustion function. In addition, the structure of the burner frame can miniaturize the components for realizing high-temperature air combustion, so that it has more application space and value, and in addition, it has low noise, full combustion, and low exhaust gas pollution. When it is applied to gas water heaters and related products and equipment including gas wall-mounted boilers that use gas combustion to generate high-temperature hot water for family bathing and heating, it not only meets the requirements, but also brings the effects of full combustion and low pollutant emissions that the burners in existing water heaters do not have. Moreover, the fuel gas can be injected only by opening a fuel gas outlet on the combustion chamber. The structure is simple and easy to implement, and the structure of the entire burner is more compact and the volume is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 It is a structural schematic diagram of an embodiment of a burner of the present invention;

[0029] Figure 2 for Figure 1 A schematic diagram of the structure of the burner from a top view;

[0030] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the middle line AA;

[0031] Figure 4 for Figure 2 Schematic diagram of the cross-sectional structure along the middle edge BB;

[0032] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure of the middle edge CC.

[0033] Description of Figure Numbers:

[0034] Label name Label name Label name 10 Burner 131 Air Inlet 160 shell 100 case 132 Spiral channel 170 First cylinder 110 Air distribution chamber 140 Air preheating chamber 180 Second cylinder 111 Air Inlet 141 Air outlet 200 Preheat burner 120 Gas distribution room 150 Combustion Chamber 300 Spiral components 121 Gas import 151 Smoke outlet 310 Center retaining ring 130 Premixing room 152 Gas outlet 320 Spiral blade

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text is to include three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or a solution that satisfies both A and B.

[0038] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0039] The purpose of the present invention is to utilize the characteristics of high-temperature air combustion to design a new type of burner and apply it to a gas water heater, so that the gas water heater can effectively reduce the emission of CO and NOx and reduce the noise of the gas water heater.

[0040] The present invention proposes a burner suitable for gas water heaters and related products and equipment including gas wall-mounted boilers that use gas combustion to generate high-temperature hot water for home bathing and heating, etc. For ease of understanding, the following application to gas water heaters is taken as an example.

[0041] In the embodiment of the present invention, Figures 1 to 4 As shown, the burner 10 includes a housing 100 and a preheating burner 200. The housing 100 is formed with a premixing chamber 130, an air preheating chamber 140 and a combustion chamber 150 which are connected in sequence. The premixing chamber 130 has an air inlet 131 for receiving air and gas, and the air preheating chamber 140 has an air outlet 141 for air to flow into it. The combustion chamber 150 has a smoke outlet 151 and a gas outlet 152. The gas outlet 152 is used to inject gas into the combustion chamber 150 so that a high-temperature air combustion reaction is carried out in the combustion chamber 150. The preheating burner 200 is installed in the air preheating chamber 140. The preheating burner 200 is used to ignite the mixed gas discharged from the premixing chamber 130 to the air preheating chamber 140, and heat the temperature in the air preheating chamber 140 to a preset temperature.

[0042] The main characteristics of high-temperature air combustion are: the chemical reaction mainly occurs in a high-temperature, low-oxygen environment, the reactant temperature is higher than its natural temperature, and the maximum temperature rise during the combustion process is lower than its natural temperature, and the oxygen volume fraction is diluted to an extremely low concentration by the combustion products. Compared with conventional combustion, in this combustion state, the pyrolysis of the fuel is suppressed, the flame thickness becomes thicker, and the flame front disappears, so that the temperature in the entire furnace is very uniform, the peak combustion temperature is low and the noise is extremely low, and the pollutant NOx and CO emissions are greatly reduced. However, achieving high-temperature air combustion requires certain conditions: it is necessary to ensure that the oxygen concentration at any position in the furnace is lower than a certain value, generally lower than 5% to 10%, to ensure that the gas is fully combusted and burned evenly, and the temperature must be higher than the auto-ignition point of the fuel to maintain auto-ignition.

[0043] In this embodiment, the cross-sectional shape of the housing 100 can be rectangular, circular, elliptical, or irregular, and can be selected and designed according to actual needs, and no specific limitation is made here. The premixing chamber 130, the air preheating chamber 140, and the combustion chamber 150 can be connected in a straight line arrangement (the wind passage is a straight line), or in a turning line arrangement (the wind passage is a broken line), or in a layered surrounding manner (the air flow is blown out from the inside to the outside or from the outside to the inside). Of course, the premixing chamber 130, the air preheating chamber 140, and the combustion chamber 150 can also be arranged in a straight line and surrounded manner, and the premixing chamber 130, the air preheating chamber 140, and the combustion chamber 150 only need to be connected in sequence, and no specific limitation is made here. The cross-sectional shape of the premixing chamber 130, the air preheating chamber 140, and the combustion chamber 150 can be circular, elliptical, annular, rectangular, etc., and can be selected and designed according to the actual shape of the housing 100 and the arrangement of the three.

[0044] In order to make the combustion more complete, the gas entering from the air inlet 131 is a mixed gas of fuel gas and air mixed by the premixer. The external air first enters the air distribution chamber 110 of the housing 100, and then enters the air preheating chamber 140 from the air outlet 141. The air flow can be blown into the air distribution chamber 110 by a blower or other device, and then enters the air preheating chamber 140 relatively evenly through the air outlet 141. It should be noted that the air outlet 141 is arranged at the outlet end of the preheating burner 200. That is, when the mixed gas in the premixing chamber 130 is burned by the preheating burner 200, the high-temperature flue gas enters the air preheating chamber 140, and at the same time, the air enters the air preheating chamber 140 from the air outlet 141, so that the cold air is mixed with the high-temperature flue gas in the air preheating chamber 140, thereby heating the cold air. The heated air and high-temperature flue gas enter the combustion chamber 150 to heat the combustion chamber 150. In order to fully and evenly mix the air with the high-temperature flue gas generated during combustion in the air preheating chamber 140, there can be multiple air outlets 141, and the multiple air outlets 141 are arranged at intervals around the peripheral wall surface of the air preheating chamber 140. The multiple air outlets 141 can comb the air into multiple uniform airflows, so that the air and the high-temperature flue gas burned in the air preheating chamber 140 are mixed more fully and evenly. In order to further stir the cold air and high-temperature flue gas in the air preheating chamber 140, a stirring device can be provided in the air preheating chamber 140 to fully stir and mix the cold air and high-temperature flue gas, so that the air is quickly and evenly heated to a preset temperature.

[0045] The gas in the gas distribution chamber 120 can be controlled by an external gas valve. It is understandable that, since the gas valve has a certain gas pressure when it is opened, the gas in the gas distribution chamber 120 can be sprayed from the gas outlet 152 into the combustion chamber 150. The gas outlet 152 can be an opening opened on the wall of the shell 100, or it can be an airflow outlet of a gas nozzle or a gas nozzle, and the gas should be sprayed from the gas outlet 152 of the gas injection device to achieve a high-speed jet. The high-speed injected gas forms a suction effect in the combustion chamber 150, so that a jet burner and a flue gas recirculation zone are formed in the combustion chamber 150, and the high-temperature flue gas in the combustion chamber 150 circulates rapidly and strongly in the combustion chamber 150, and then the injected gas and the incoming air are fully diluted to form a lower oxygen concentration, reduce the combustion reaction speed, and maintain a higher temperature in the combustion chamber 150, keeping the temperature higher than the auto-ignition point of the fuel to achieve auto-ignition. In this way, this embodiment meets the conditions of high-temperature air combustion (MILD combustion): high-temperature preheated air is combined with high-speed jets to achieve the entrainment of high-temperature flue gas and dilute the ignition air jet, so that the oxygen concentration is lower than a certain value and the temperature is higher than the auto-ignition point of the fuel.

[0046] The preheating burner 200 can be specifically a full premixing burner. The preheating burner 200 can be installed in the air preheating chamber 140, or it can be installed at the gas flow port between the premixing chamber 130 and the air preheating chamber 140. The preheating burner 200 is used to ignite the mixed gas discharged from the premixing chamber 130 to the air preheating chamber 140. Specifically, the burner 10 also includes an ignition device arranged in the shell 100 adjacent to the preheating burner 200, and the ignition device is used to ignite the preheating burner 200. In order to ensure uniform combustion, the preheating burner 200 includes a plate-like body and a plurality of air holes arranged in the thickness direction of the plate-like body, and the plurality of air holes are used for the mixed gas to pass through and enter the air preheating chamber 140. The plurality of air holes can be evenly or staggeredly arranged on the plate-like body to ensure uniform combustion. The ignition device can be specifically an electronic igniter or an electric heating wire, so that the power consumption is smaller.

[0047] When the burner 10 is working, the mixed gas is transported from the air inlet 131 to the spiral channel 132 of the premixing chamber 130, and the gas and air are evenly mixed in the spiral channel 132 and then transported to the preheating burner 200. The preheating burner 200 is ignited by the ignition device. After the mixed gas is burned, the high-temperature flue gas enters the air preheating chamber 140. At the same time, the air enters the air preheating chamber 140 from the air distribution chamber 110 through the air outlet 141. The high-temperature flue gas mixes with the cold air to heat the cold air. It can be understood that by controlling the heating temperature, the air in the air preheating chamber 140 can be heated to the target temperature, that is, the preset temperature mentioned above, so that the high-temperature preheating of the air is achieved. Specifically, the burner 10 also includes a temperature measuring device, which is arranged in the air preheating chamber 140. The temperature measuring device is used to detect whether the gas temperature in the air preheating chamber 140 reaches the target temperature. If not, the temperature in the air preheating chamber 140 needs to be increased. The air intake volume can be controlled, or the ratio of gas and air in the premixing chamber 130 can be controlled to achieve temperature regulation. By detecting the temperature, the preheating burner 200 can automatically adjust the heat load according to the amount of air required for the combustion of MILD to achieve the effect of rapid preheating of the air, while ensuring low CO and NOX emissions during the entire combustion process. The temperature measuring device can be a temperature sensor. After the high-temperature preheated air and high-temperature flue gas are transported to the combustion chamber 150, the gas outlet 152 is controlled to spray gas, the gas contacts the high-temperature gas, and the high-temperature gas ignites the gas to achieve MILD combustion in the combustion chamber 150. The heat after combustion is discharged through the flue gas outlet 151, and then it can be heat exchanged with the heat exchanger of the gas water heater to achieve hot water.

[0048] In the embodiment of the present invention, by providing a premixing chamber 130, an air preheating chamber 140 and a combustion chamber 150 which are connected in sequence in the housing 100, the preheating burner 200 ignites and burns the mixed gas, realizing high-temperature preheated air, and then the gas is sprayed through the gas outlet 152 to cooperate and produce the entrainment effect, so that the high-temperature flue gas refluxes, on the one hand, to achieve heat preservation so that the temperature is higher than the auto-ignition point of the fuel, so that the gas in the combustion chamber can self-ignite, and on the other hand, the air is diluted by jet entrainment, so that the oxygen concentration is lower than a certain value, and uniform combustion is achieved, so that high-temperature air combustion occurs in the combustion chamber 150. In other words, the technical solution of this embodiment is conducive to achieving these two conditions at the same time, and high-temperature air combustion is smoothly achieved. Moreover, the structure of the burner frame can miniaturize the components for high-temperature air combustion, so that it has more application space and value. In addition, it has low noise, complete combustion, and low exhaust gas pollution. When applied to gas water heaters and related products and equipment including gas wall-mounted boilers that use gas combustion to generate high-temperature hot water for family bathing and heating, it not only meets the requirements, but also brings the effects of complete combustion and low pollutant emissions that the burners in existing water heaters do not have. And only by opening the gas outlet 152 on the combustion chamber 150 can the gas be injected, which has a simple structure and is easy to implement, and makes the structure of the entire burner 10 more compact and smaller.

[0049] In the above embodiment, in order to better obtain a mixed gas of gas and air, the premixer includes a housing, a fan and a gas switch valve, the housing is formed with an air inlet duct, a gas flow channel and a mixing channel, the mixing channel is connected with the air inlet duct and the gas flow channel respectively, the fan is arranged in the air inlet duct, the gas switch valve is arranged in the gas flow channel, and the mixing channel is connected with the air inlet 131 of the mixed gas distribution chamber. When mixed gas is needed, the fan is controlled to work and the gas switch valve is controlled to open according to the preset air inlet and gas ratio, so as to obtain a mixed gas with a certain gas / air ratio in the housing.

[0050] In one embodiment, please refer to Figure 3 and Figure 4 The shell 100 includes an outer shell 160 and a first cylinder 170 disposed in the outer shell 160. A combustion chamber 150 is defined in the first cylinder 170. A gas distribution chamber 120 is defined between the first cylinder 170 and the outer shell 160. The gas distribution chamber 120 has a gas inlet 121 and a plurality of gas outlets 152. The plurality of gas outlets 152 are opened on the peripheral wall surface of the first cylinder 170 and are arranged at intervals along the circumference of the first cylinder 170.

[0051] In this embodiment, the shape of the shell 160 can be many. In order to maintain the overall consistency and make the overall structure of the burner 10 more compact, the shell 160 can be set in a cylindrical shape as a whole. The gas inlet 121 is connected to a gas inlet pipe, which is connected to the gas source to input the gas. A plurality of gas outlets 152 are provided on the peripheral wall surface of the first cylinder 170, so that the gas can be sprayed from the gas distribution chamber 120 into the combustion chamber 150 through the gas outlets 152, meeting the high-speed jet condition of the gas. And the plurality of gas injection ports make the gas in the combustion chamber 150 more evenly mixed, so that the combustion is slower and more complete. The gas outlet 152 can be provided at the upper end of the first cylinder 170, and the outflow direction corresponding to the gas outlet 152 can be downward, or the gas outlet 152 can be provided at the lower end of the first cylinder 170, and the outflow direction corresponding to the gas outlet 152 can be upward.

[0052] Furthermore, the housing 100 further includes a second barrel 180 disposed in the outer shell 160, and an air preheating chamber 140 and a premixing chamber 130 are defined in the second barrel 180. An air distribution chamber 110 is defined between the second barrel 180 and the outer shell 160. The air distribution chamber 110 has an air inlet 111 and a plurality of air outlets 141. The plurality of air outlets 141 are provided on the peripheral wall surface of the second barrel 180 and are arranged at intervals along the circumference of the second barrel 180. The air inlet 111 is connected to an air intake pipe, which is connected to an air source and can be input with air through a blower or the like. Only by disposing the first barrel 170 and the second barrel 180 in the outer shell 160, the gas distribution chamber 120, the air distribution chamber 110, the air preheating chamber 140, the combustion chamber 150 and the premixing chamber 130 can be defined respectively. The overall structure is simple and the design is ingenious, so that the entire burner 10 has a small volume, occupies a small space and has a beautiful appearance.

[0053] On the basis of the above embodiments, further, Figure 3 and Figure 4 As shown, the premixing chamber 130, the air preheating chamber 140, and the combustion chamber 150 are arranged in sequence from bottom to top, and the gas outlet 152 is arranged at the upper end of the first cylinder 170, and the airflow direction of the gas outlet 152 is downward or tilted downward. In this way, the air intake direction of the entire burner 10 is from bottom to top, which conforms to the airflow flow characteristics, making the airflow flow smoother. The first cylinder 170 is located above the second cylinder 180, and the outer shell 160 surrounds the first cylinder 170 and the second cylinder 180, maintaining the overall consistency of the appearance, and the layout is more compact and reasonable. The gas outlet 152 is arranged at the upper end of the first cylinder 170, and the airflow of the gas outlet 152 is downward or tilted downward, then the gas is ejected downward from the gas outlet 152, forming a suction effect in the combustion chamber 150, making the gas mixing more uniform, and the combustion slower and more complete.

[0054] Specifically, Figure 1 , Figure 3 and Figure 4 As shown, the upper end of the first cylinder 170 is gradually tapered from bottom to top. In this way, the upper end of the first cylinder 170 is tapered from bottom to top. When the gas outlet 152 is arranged at the upper end of the first cylinder 170, the gas outlet 152 is arranged obliquely downward, and the multiple gas outlets 152 arranged at intervals in the circumferential direction all spray gas obliquely downward toward the middle of the air preheating chamber 140, so that the gas in the combustion chamber 150 can be mixed more evenly and the combustion can be slower and more complete.

[0055] In one embodiment, please refer to Figures 3 to 5 The burner 10 further includes a spiral assembly 300 , which is installed in the premixing chamber 130 so that a spiral channel 132 is formed in the premixing chamber 130 , the inlet of the spiral channel 132 is connected to the air inlet 131 , and the outlet of the spiral channel 132 is connected to the air preheating chamber 140 .

[0056] In the present embodiment, the spiral assembly 300 may include a spiral blade 320, and the spiral blade 320 extends in an axial spiral direction of the premixing chamber 130, so that the spiral blade 320 and the inner wall surface of the premixing chamber 130 are enclosed to form a spiral channel 132. In one embodiment, the spiral assembly 300 includes a spiral coil, and a spiral channel 132 is formed in the spiral coil. By forming the spiral channel 132 in the spiral coil, the structure is simple and easy to implement. It should be noted that the spiral channel 132 means that the channel extends in a spiral shape, and when the airflow flows through the spiral channel 132, the flow path of the airflow is also spiral. By installing the spiral assembly 300 in the premixing chamber 130 to form the spiral channel 132, compared with the premixing chamber 130 without the spiral assembly 300, the flow path of the airflow is longer, and the airflow is caused to generate a rotation direction in the spiral channel 132. Therefore, when the gas and air enter the spiral channel 132 from the air inlet 131, they are fully and evenly mixed in the spiral channel 132, and then transported from the outlet of the spiral channel 132 to the preheating burner 200 for combustion, which makes the combustion more complete, and the pollutant emissions and noise during the combustion process are low.

[0057] In one embodiment, please refer to Figures 3 to 5 The spiral assembly 300 includes a center retaining ring 310 and a spiral blade 320 , the inner end of the spiral blade 320 is connected to the center retaining ring 310 , and the outer end of the spiral blade 320 is connected to the inner wall surface of the premixing chamber 130 , so that a spiral channel 132 is defined between the spiral blade 320 , the center retaining ring 310 and the shell 100 .

[0058] In this embodiment, it can be understood that the center retaining ring 310 is a columnar structure and a closed structure, so as to prevent the mixed air flow from entering the center retaining ring 310 and affecting the mixing effect of the gas and air. The center retaining ring 310 is arranged in the middle of the premixing chamber, and the extension direction of the center retaining ring 310 is consistent with the extension direction of the premixing chamber 130. Then the spiral blade 320 extends along the axis of the center retaining ring 310, that is, the spiral blade 320 extends along the axis of the premixing chamber 130. The spiral blade 320 can be fixedly connected with the center retaining ring 310 and the shell 100 by welding or integral molding. By connecting the inner end of the spiral blade 320 to the center retaining ring 310 and the outer end to the inner wall surface of the shell 100, a spiral channel 132 is defined between the outer wall surface of the spiral blade 320, the center retaining ring 310 and the inner wall surface of the premixing chamber 130. The structure of the spiral blade 320 plus the center retaining ring 310 forms a spiral channel 132 in the premixing chamber 130 . The structure is simple and easy to manufacture. Compared with forming the spiral channel 132 in a spiral coil, the space in the premixing chamber 130 can be fully utilized, thereby maximizing the air flow area of ​​the spiral channel 132 and effectively improving the gas mixing rate and flow rate of the premixing chamber 130 .

[0059] On the basis of the above embodiments, further, Figure 3 and Figure 4 As shown, the helical angle of the spiral blade 320 is greater than or equal to 10 degrees and less than or equal to 45 degrees. Specifically, the helical angle of the spiral blade 320 can be 10 degrees, 15 degrees, 18 degrees, 20 degrees, 25 degrees, 27 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, etc. If the helical angle of the spiral blade 320 is less than 10 degrees, the path of the spiral channel 132 is too long, the airflow loss is large, and the time for a single delivery of the mixed gas becomes longer, then the gas flow rate of the premixing chamber 130 becomes low, so that the mixed gas in the premixing chamber 130 cannot meet the use requirements. When the helical angle of the spiral blade 320 is greater than 45 degrees, the path of the spiral channel 132 is too short, so that the gas and air cannot be fully mixed after entering the spiral channel 132. By making the helical angle of the spiral blade 320 greater than or equal to 10 degrees and less than or equal to 45 degrees, the gas flow rate of the premixing chamber 130 is improved and the airflow loss is reduced on the premise that the gas and air can be fully mixed.

[0060] In combination with the above embodiment in which the spiral assembly 300 includes the spiral blade 320, further, the ratio of the extended height of the premixing chamber 130 to the extended height of the spiral blade 320 is greater than or equal to 1.2 and less than or equal to 2. Specifically, the ratio of the extended height of the premixing chamber 130 to the extended height of the spiral blade 320 can be 1.2, 1.3, 1.5, 1.8, 2, etc.

[0061] It should be noted that the extended height of the spiral blade 320 refers to the overall height of the spiral blade 320, that is, the height from the bottom to the top of the spiral blade 320 along the axial direction of the spiral blade 320. The extended height of the premixing chamber 130 refers to the height of the premixing chamber 130 along its axial direction. When the ratio of the extended height of the premixing chamber 130 to the extended height of the spiral blade 320 is less than 1.2, the spiral blade 320 is too long, filling the entire premixing chamber 130, or extending out of the premixing chamber 130, so that the mixed airflow output from the outlet of the spiral channel 132 does not have enough space for buffering, and directly enters the preheating burner 200 for combustion. Since the wind area of ​​the outlet of the spiral channel 132 is relatively small, the mixed airflow cannot cover the entire preheating burner 200, and thus the best combustion effect cannot be achieved. When the ratio of the extension height of the premixing chamber 130 to the extension height of the spiral blade 320 is greater than or equal to 2, the entire spiral blade 320 occupies a relatively small proportion in the premixing chamber 130, and the length of the spiral channel 132 is relatively short, so that the effect of fully mixing the gas and the air cannot be achieved. By making the ratio of the extension height of the premixing chamber 130 to the extension height of the spiral blade 320 greater than or equal to 1.2 and less than or equal to 2, the gas and the air can be fully mixed in the spiral channel 132, and the mixed gas flow blown out from the outlet of the spiral channel 132 has enough space in the premixing chamber 130 for buffering, and the mixed gas transported from the premixing chamber 130 to the preheating burner 200 can cover the entire preheating burner 200, thereby enabling the preheating burner 200 to achieve the best combustion effect.

[0062] In one embodiment, please refer to Figure 5 , the ratio of the equivalent inner diameter of the premixing chamber 130 to the equivalent outer diameter of the center retaining ring 310 is greater than or equal to 1.5 and less than or equal to 4. Specifically, the ratio of the equivalent inner diameter of the premixing chamber 130 to the equivalent outer diameter of the center retaining ring 310 can be 1.5, 1.8, 2, 2.5, 3, 3.5, 4, etc.

[0063] It is understood that when the cross-sectional shape of the premixing chamber 130 is a polygon, such as a rectangle, the equivalent inner diameter of the premixing chamber 130 is the diameter of the inscribed circle of the polygon. When the cross-sectional shape of the premixing chamber 130 is an ellipse, the equivalent inner diameter of the premixing chamber 130 is the length of the minor axis of the ellipse. When the cross-sectional shape of the premixing chamber 130 is a circle, the equivalent inner diameter of the premixing chamber 130 is the diameter of the circle. The cross-sectional shape of the center retaining ring 310 can be a circle, a rectangle, an ellipse, etc. Then, when the cross-sectional shape of the center retaining ring 310 is a circle, the equivalent outer diameter of the center retaining ring 310 is the diameter of the circle. When the cross-sectional shape of the center retaining ring 310 is an ellipse, the equivalent outer diameter of the center retaining ring 310 is the length of the major axis of the ellipse. When the cross-sectional shape of the center retaining ring 310 is a polygon, such as a rectangle, the equivalent outer diameter of the center retaining ring 310 is the diameter of the circumscribed circle of the polygon. For ease of understanding, the following detailed description will be given assuming that the cross-sectional shape of the premixing chamber 130 and the cross-sectional shape of the center retaining ring 310 are both circular.

[0064] When the ratio of the equivalent inner diameter of the premixing chamber 130 to the equivalent outer diameter of the center retaining ring 310 is less than 1.5, the diameter of the center retaining ring 310 is too large, so that the inner diameter of the spiral passage is too small, the amount of mixed gas delivered at a single time becomes smaller, and the gas flow rate of the premixing chamber 130 becomes low, so that the mixed gas in the premixing chamber 130 cannot meet the use requirements. When the ratio of the equivalent inner diameter of the premixing chamber 130 to the equivalent outer diameter of the center retaining ring 310 is greater than 4, the diameter of the center retaining ring 310 is too small, and the overall area and weight of the spiral blade 320 are large, the strength of the center retaining ring 310 is small, and it is not enough to support the connection of the spiral blade 320, so when the mixed gas flows through the spiral channel 132, the center retaining ring 310 will shake, thereby generating noise, or the connection between the spiral blade 320 and the center retaining ring 310 will be broken. By making the ratio of the equivalent inner diameter of the premixing chamber 130 to the equivalent outer diameter of the center retaining ring 310 greater than or equal to 1.5 and less than or equal to 4, the gas flow rate and the amount of mixed gas in the premixing chamber 130 can meet the use requirements while ensuring the connection stability between the spiral blade 320 and the center retaining ring 310, thereby effectively reducing noise.

[0065] Furthermore, if Figure 3 and Figure 4 As shown, the bottom of the center retaining ring 310 is spaced apart from the bottom wall of the premixing chamber 130. By making the bottom of the center retaining ring 310 spaced apart from the bottom wall of the premixing chamber 130, the center retaining ring 310 is suspended and fixed to the housing 100 through the spiral blades 320. In this way, when the mixed airflow flows through the spiral channel 132, the vibration of the center retaining ring 310 can be prevented from being transmitted to the bottom wall of the premixing chamber 130, thereby effectively reducing noise.

[0066] The present invention also provides a gas water heater, including a main body, a heat exchanger and a burner 10, wherein a heat exchange chamber and a smoke exhaust port connected to the heat exchange chamber are arranged in the main body, the heat exchanger is arranged in the heat exchange chamber, and the smoke outlet 151 of the burner 10 is connected to the heat exchange chamber. It should be noted that the gas of the gas distribution chamber 120 can be provided through an external gas pipeline, and a gas proportional valve is arranged on the gas pipeline for control, and the air of the air distribution chamber 110 is controlled by an independent fan, which is independent of the fan of the premixer.

[0067] The detailed structure of the burner 10 can refer to the embodiment of the above-mentioned burner 10, which will not be repeated here; it can be understood that since the above-mentioned burner 10 is used in the gas water heater of the present invention, the embodiment of the gas water heater of the present invention includes all technical solutions of all embodiments of the above-mentioned burner 10, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0068] In combination with the above-mentioned embodiment of the burner 10, the working principle of the burner 10 of the present invention applied to a gas water heater is described:

[0069] When the water heater is started, the gas switch valve of the premixer and the fan provide the air and gas mixed in a certain proportion to the premixing chamber 130 through the air inlet 131. After being stirred and fully mixed by the turbulence device, the air and gas are provided to the preheating burner 200. The ignition device ignites, and combustion begins in the combustion zone of the air preheating chamber 140. The fan corresponding to the air distribution chamber 110 also operates to inhale the air required for combustion. The cold air and the high-temperature flue gas generated by the combustion of the preheating burner 200 are mixed in the air preheating chamber 140 to form high-temperature gas. When the temperature measuring device detects that the temperature of the high-temperature gas reaches the temperature required for MILD combustion, the gas valve provides gas to the gas distribution chamber 120, and the gas required for MILD combustion is sprayed from the gas outlet 152 to the combustion chamber 150 to combine with the high-temperature gas, and the high-temperature gas ignites the gas to achieve MILD combustion in the combustion chamber 150. Since the gas is sprayed through the gas outlet 152, an entrainment effect is formed in the combustion chamber 150, so that a jet combustion zone and a flue gas recirculation zone are formed in the combustion chamber 150, so that part of the flue gas circulates strongly in the combustion chamber 150, and then the injected gas and air are fully diluted to form a lower oxygen concentration, reduce the combustion reaction speed, and maintain a higher temperature in the combustion chamber 150 to ensure that the temperature is higher than the auto-ignition point of the fuel, so as to achieve auto-ignition. In this way, this embodiment meets the conditions of high-temperature air combustion (MILD combustion): high-temperature preheated air and high-speed jets are used to achieve entrainment of high-temperature flue gas and dilute the ignition air jet, so that the oxygen concentration is lower than a certain value, and the temperature is higher than the auto-ignition point of the fuel. The heat after combustion can be exchanged with the heat exchanger of the gas water heater and then discharged to the outside to produce hot water.

[0070] It can be understood that, since the burner 10 is used in the gas water heater, the gas water heater can effectively reduce the emission of CO and NOx and reduce the noise of the gas water heater.

[0071] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A burner, characterized in that: include: a shell, wherein a premixing chamber, an air preheating chamber and a combustion chamber are sequentially connected to each other, the premixing chamber has an air inlet for receiving air and gas, the air preheating chamber has an air outlet for air to flow into the premixing chamber, the combustion chamber has a smoke outlet and a gas outlet, and the gas outlet is used to inject gas into the combustion chamber so that a high-temperature air combustion reaction is carried out in the combustion chamber; as well as a preheating burner installed in the air preheating chamber, the preheating burner being used to ignite the mixed gas discharged from the premixing chamber into the air preheating chamber and heat the temperature in the air preheating chamber to a preset temperature; The burner further comprises a spiral assembly, which is mounted on the premixing chamber so that a spiral channel is formed in the premixing chamber, the inlet of the spiral channel is communicated with the air inlet, and the outlet of the spiral channel is communicated with the air preheating chamber; The preheating burner includes a plate-like body and a plurality of air holes arranged through the thickness direction of the plate-like body. The plurality of air holes are used for allowing the mixed gas to pass through and enter the air preheating chamber.

2. The burner according to claim 1, characterized in that The housing comprises an outer shell and a first cylinder disposed in the outer shell, wherein the combustion chamber is defined in the first cylinder; A gas distribution chamber is defined between the first cylinder and the outer shell, the gas outlet is communicated with the gas distribution chamber, and the gas distribution chamber has a gas inlet.

3. The burner according to claim 2, characterized in that There are multiple gas outlets, which are opened on the peripheral wall surface of the first cylinder and are arranged at intervals along the circumference of the first cylinder.

4. The burner according to claim 2, characterized in that The shell also includes a second cylinder arranged in the outer shell, the air preheating chamber and the premixing chamber are defined in the second cylinder, an air distribution chamber is defined between the second cylinder and the outer shell, the air distribution chamber has an air inlet, and there are multiple air outlets, the multiple air outlets are opened on the peripheral wall surface of the second cylinder, and are arranged at intervals along the circumference of the second cylinder.

5. The burner according to claim 4, characterized in that The premixing chamber, the air preheating chamber, and the combustion chamber are arranged in sequence from bottom to top, the gas outlet is arranged at the upper end of the first cylinder, and the gas flow direction of the gas outlet is arranged downward.

6. The burner according to claim 1, characterized in that The spiral assembly includes a central retaining ring and a spiral blade, wherein the inner end of the spiral blade is connected to the central retaining ring, and the outer end of the spiral blade is connected to the inner wall surface of the premixing chamber, so that the spiral channel is defined between the spiral blade, the central retaining ring and the shell.

7. The burner according to claim 6, characterized in that The helical angle of the spiral blade is greater than or equal to 10 degrees and less than or equal to 45 degrees.

8. The burner according to claim 6, characterized in that The ratio of the extended height of the premixing chamber to the extended height of the spiral blade is greater than or equal to 1.2 and less than or equal to 2.

9. The burner according to claim 6, characterized in that The ratio of the inner diameter of the premixing chamber to the outer diameter of the central retaining ring is greater than or equal to 1.5 and less than or equal to 4.

10. The burner according to claim 6, characterized in that The bottom of the central retaining ring is spaced apart from the bottom wall of the premixing chamber.

11. A gas water heater, characterized in that: It comprises a main body, a heat exchanger and a burner as claimed in any one of claims 1 to 10, wherein a heat exchange chamber and a smoke exhaust port connected to the heat exchange chamber are arranged in the main body, the heat exchanger is arranged in the heat exchange chamber, and the smoke outlet of the burner is connected to the heat exchange chamber.

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