Fire grate, burner and water heater

Abstract

The application discloses a fire grate, a burner and a water heater, and relates to the technical field of water heaters. The fire grate comprises a fire grate body, the fire grate body is provided with a mixing cavity, a first injection flow channel and a second injection flow channel, the mixing cavity is provided with a fire port, the air inlet end of the first injection flow channel is provided with a first injection port, the air outlet end of the first injection flow channel is provided with an air outlet, the air inlet end of the second injection flow channel is provided with a second injection port, the second injection port is in communication with the air outlet and the external environment respectively, the air outlet end of the second injection flow channel is in communication with the mixing cavity, the first injection port is used for conveying fuel gas and air to the first injection flow channel, the second injection port is used for conveying air and fuel gas from the air outlet to the second injection flow channel, and air from the external environment, the mixing cavity is provided with a second diverging section, the second diverging section is in communication with the fire port, and the flow area of the second diverging section is arranged to increase from the second injection flow channel to the fire port. The technical scheme can reduce the generation of thermal nitrogen oxides.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water heaters, in particular to a fire grate, a burner and a water heater. BACKGROUND

[0002] The burner of the conventional gas water heater often has insufficient primary air coefficient when air is introduced, and the gas and air are not mixed sufficiently before combustion, and the local temperature of the flame is high during combustion, resulting in a large amount of thermal nitrogen oxides being generated. SUMMARY

[0003] The main purpose of the present application is to provide a fire grate, a burner and a water heater, which aims to reduce the generation of thermal nitrogen oxides during combustion.

[0004] To achieve the above-mentioned purpose, the fire grate provided by the present application comprises a fire grate body, the fire grate body has a mixing cavity, a first ejector flow channel and a second ejector flow channel, the mixing cavity is provided with a fire port, the air inlet end of the first ejector flow channel is provided with a first ejector port, the air outlet end of the first ejector flow channel is provided with an air outlet, the air inlet end of the second ejector flow channel is provided with a second ejector port, the second ejector port is respectively communicated with the air outlet and the external environment, the air outlet end of the second ejector flow channel is communicated with the mixing cavity, the first ejector port is used for conveying gas and air to the first ejector flow channel, the second ejector port is used for conveying air and gas from the air outlet to the second ejector flow channel, and is also used for conveying air from the external environment to the second ejector flow channel.

[0005] The mixing cavity has a second diverging section, the second diverging section is communicated with the fire port, and the flow area of the second diverging section is arranged to increase from the second ejector flow channel to the fire port.

[0006] In an embodiment, the first ejector flow channel has a first converging section, the first converging section is communicated with the air outlet, and the flow area of the first converging section is arranged to decrease from the first ejector port to the air outlet.

[0007] In an embodiment, the second ejector flow channel has a second converging section, the second converging section is arranged close to the second ejector port, and the flow area of the second converging section is arranged to decrease from the second ejector port to the air outlet end of the second ejector flow channel.

[0008] In an embodiment, the first converging section and the second converging section are arranged to extend along a first direction.

[0009] In an embodiment, the maximum flow area of the first converging section is greater than the maximum flow area of the second converging section.

[0010] And / or, the minimum flow area of the first tapered section is smaller than the minimum flow area of the second tapered section.

[0011] In an embodiment, the second tapered section has two first inner wall surfaces oppositely arranged along a third direction, and two second inner wall surfaces oppositely arranged along a second direction, the two first inner wall surfaces and the two second inner wall surfaces enclosing the second tapered section, the second direction and the third direction being intersected.

[0012] In a direction from the second injection port to an exhaust end of the second injection passage, the two second inner wall surfaces are arranged away from each other, and the two first inner wall surfaces are arranged close to each other.

[0013] In an embodiment, the second injection passage further has a second throat section and a first diverging section, the second throat section connecting the second tapered section and the first diverging section, the flow area of the first diverging section being arranged to increase from the second throat section to the exhaust end of the second injection passage.

[0014] In an embodiment, the first injection passage further has a first intake section, the first intake section being located between the first injection port and the first tapered section, and connecting the first injection port and the first tapered section.

[0015] And / or, the second injection passage further has a second intake section, the second intake section being located between the second injection port and the second tapered section, and connecting the second injection port and the second tapered section.

[0016] In an embodiment, the firebox body comprises a first flow portion and a second flow portion, the first flow portion being internally configured with the first injection passage, the second flow portion being internally configured with the second injection passage, the first flow portion and the second flow portion being arranged in sequence along a first direction.

[0017] An outer surface of the first flow portion is provided with a first flow guide surface, the first flow guide surface being used to guide ambient air to flow toward the second injection port, the first flow guide surface being arranged to tilt from an outer periphery of the exhaust port to a center of the exhaust port in an extending direction toward the second injection port.

[0018] In an embodiment, the exhaust port has a smaller diameter than the second injection port.

[0019] The exhaust port and the second injection port are arranged to be nested inside and outside each other, or the exhaust port is located inside the second injection passage.

[0020] In one embodiment, the mixing chamber has a second expanding section that connects to the ignition port, and the flow cross-sectional area of ​​the second expanding section increases from the second ejector channel toward the ignition port.

[0021] The present invention also proposes a burner comprising the fire bar as described above.

[0022] The present invention also proposes a water heater, including the burner described above.

[0023] The technical solution of this invention involves configuring a burner including a burner body, the burner body having a mixing chamber, a first ejector channel, and a second ejector channel, the mixing chamber having a burner opening for combustion, the first ejector channel having a first ejector port and an exhaust port, the second ejector channel having a second ejector port communicating with the exhaust port and the external environment, and the exhaust end of the second ejector channel communicating with the mixing chamber. Combustion gas and air are supplied to the first ejector channel through the first ejector port, and air and combustion gas from the exhaust port, as well as air from the external environment, are supplied to the second ejector channel through the second ejector port. Thus, combustion gas and air can be supplied through the first ejector port and the second ejector channel. The injector repeatedly introduces air to mix with the combustion gas, increasing the primary air coefficient of the burner intake and preventing overall high temperatures during combustion at the burner location. The mixing chamber is equipped with a second gradually expanding section connected to the burner, with the cross-sectional area of ​​this section increasing from the second injector channel towards the burner. This allows for multiple mixing of the combustion gas and air through the first and second injector channels and the mixing chamber, improving gas mixing uniformity and resulting in a more balanced proportion of combustion gas injected into each area of ​​the burner. This leads to a more uniform flame distribution in each area, preventing localized high temperatures during combustion and significantly reducing the generation of thermal nitrogen oxides, thus lowering harmful emissions. Attached Figure Description

[0024] 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.

[0025] Figure 1 A schematic diagram of the structure of an embodiment of the fire briquette provided by the present invention;

[0026] Figure 2 for Figure 1 A structural diagram of the center burner from another angle;

[0027] Figure 3 for Figure 2 Partial sectional view at AA;

[0028] Figure 4 As Figure 1 Structure diagram of the fire grate from another angle;

[0029] Figure 5 As Figure 4 Partial sectional view at B-B;

[0030] Figure 6 As Figure 4 Partial sectional view at C-C;

[0031] Figure 7 As Figure 1 Partial sectional view of the fire grate from another angle.

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] 100, fire grate; 10, fire grate body; 101, mixing cavity; 101a, fire hole; 1011, second diverging section; 1012, third converging section; 1013, first throat section; 1014, third air inlet section; 102, first ejector flow channel; 102a, first ejector port; 102b, exhaust port; 1021, first converging section; 1022, first air inlet section; 103, second ejector flow channel; 103a, second ejector port; 1031, second converging section; 1031a, first inner wall surface; 1031b, second inner wall surface; 1032, second throat section; 1033, first diverging section; 1034, second air inlet section; 11, third throat section; 12, first flow guide part; 121, first flow guide surface; 13, second flow guide part.

[0034] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0036] It should be noted that if the embodiments of the present application 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 condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0037] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0038] With the increasingly stringent emission standards, the nitrogen oxide emission of gas water heater is paid more and more attention. The low nitrogen performance of the existing gas water heater cannot meet the standard due to the insufficient air entraining capacity of the burner, the uneven mixing and the like, and therefore it is urgent to develop a low nitrogen type fire grate suitable for the gas water heater.

[0039] The present application provides a fire grate 100.

[0040] Please refer to Figures 1 to 7 In an embodiment of the present application, the fire grate 100 comprises a fire grate body 10, the fire grate body 10 has a mixing chamber 101, a first entraining flow channel 102 and a second entraining flow channel 103, the mixing chamber 101 is provided with a fire port 101a, the air inlet end of the first entraining flow channel 102 is provided with a first entraining port 102a, the air outlet end of the first entraining flow channel 102 is provided with an air outlet 102b, the air inlet end of the second entraining flow channel 103 is provided with a second entraining port 103a, the second entraining port 103a is respectively communicated with the air outlet 102b and the external environment, the air outlet end of the second entraining flow channel 103 is communicated with the mixing chamber 101, the first entraining port 102a is used for conveying the fuel gas and air to the first entraining flow channel 102, the second entraining port 103a is used for conveying the air and fuel gas from the air outlet 102b to the second entraining flow channel 103, and conveying the air from the external environment to the second entraining flow channel 103;

[0041] The mixing chamber 101 has a second diverging section 1011, the second diverging section 1011 is communicated with the fire port 101a, and the flow area of the second diverging section 1011 is increased from the second entraining flow channel 103 to the fire port 101a.

[0042] The fire grate 100 of the present application can be used in a gas water heater. The fire grate 100 can include a fire grate body 10 and a combustion head, a mixing cavity 101 of the fire grate body 10 can be provided with a fire opening 101a, and the combustion head can be arranged at the fire opening 101a and can be used for the fire grate body 10 to inject mixed gas of fuel gas and air for combustion. The first and second injection flow channels 102 and 103 of the fire grate body 10 can be arranged along the length direction of the fire grate body 10. The first and second injection flow channels 102 and 103 can be arranged as Venturi flow channels, or the first injection flow channel 102 only includes the converging section and the throat section of the Venturi flow channel, and the second injection flow channel 103 is arranged as a Venturi flow channel. The exhaust port 102b of the first injection flow channel 102 and the second injection port 103a of the second injection flow channel 103 can be arranged in opposition and at intervals, the exhaust port can be arranged inside the second injection flow channel, or arranged outside the second injection flow channel. Alternatively, the exhaust port and the second injection port are arranged in nested relationship inside and outside, and the distance between them is zero. In order to ensure that the exhaust port transports the mixed gas of fuel gas and air into the second flow channel, and gas leakage occurs, the diameter of the exhaust port can be smaller than the diameter of the second injection port, and the exhaust port can be arranged inside the second injection port, or arranged inside the second injection flow channel.

[0043] The fire grate body can include a first flow guide portion and a second flow guide portion, the first flow guide portion is internally provided with the first injection flow channel, and the second flow guide portion is internally provided with the second injection flow channel.

[0044] When the exhaust port 102b is arranged at the throat section of the first injection flow channel 102, the flow area of the exhaust port 102b is the smallest compared with other flow areas of the first injection flow channel 102, the negative pressure generated here is the largest, and the gas flow rate is the fastest. When the exhaust port 102b transports the mixed gas of fuel gas and air to the second injection port 103a, since the second injection port 103a is connected to the external environment, under the action of the negative pressure of the exhaust port 102b, the second injection port 103a also generates a certain negative pressure, so that the gas flow rate in the open flow area outside the second injection port 103a is relatively fast, and the internal negative pressure in the open flow area is relatively large, so that the second injection port 103a can suck the air in the open flow area into the mixed gas from the exhaust port 102b. When the mixed gas of fuel gas and air is transported to the first injection flow channel 102 through the first injection port 102a, the second injection port 103a can suck the air in the external environment into the open flow area again, increase the air ratio in the mixed gas, and thus improve the primary air coefficient when the fire grate body 10 inhales air.

[0045] In addition, when the first ejector flow channel 102 introduces air and gas, and the gas and air are accelerated through the exhaust port 102b, strong disturbance can be generated at the exhaust port 102b, so that the gas and the initially introduced air can be fully mixed. Between the open airflow areas outside the second ejector port 103a, the high-speed flow of the mixed gas guides the air of the open airflow area to be quickly supplemented, so that the introduced air can be mixed with the mixed air again while the primary air coefficient is improved. At the same time, the uniformity of the mixed gas and the air introduced again can be initially improved. When the second ejector flow channel 103 adopts a Venturi flow channel, the air of the open airflow area is introduced from the position of the second ejector port 103a to mix with the mixed gas. The mixed gas can be further mixed through the acceleration-deceleration process of the internal structure of the second ejector flow channel 103, so as to ensure the mixing uniformity of the mixed gas after the primary air coefficient is improved. Therefore, when the fire row 100 is combusted through the combustion head, the overall combustion temperature of the combustion head is reduced, the proportion of the gas sprayed by each part of the combustion head tends to be more balanced and consistent, the combustion of each part of the combustion head is more balanced, and local high temperature is avoided. Therefore, the overall combustion high temperature can be prevented by improving the primary air coefficient, and the local combustion high temperature can be prevented by uniformly mixing the gas and the air, so that the generation of thermal nitrogen oxides can be greatly reduced, and the emission of harmful substances can be reduced.

[0046] Alternatively, in another embodiment, a gas pump or a fan can be used to inject the mixed gas of air and gas from the first ejector port 102a to the first ejector flow channel 102. In other embodiments, the exhaust port 102b and the second ejector port 103a can be connected and communicated, and an air inlet communicating with the external environment can be arranged between the exhaust port 102b and the second ejector port 103a to realize the air and gas from the exhaust port 102b to the second ejector flow channel 103 through the second ejector port 103a, and the air from the external environment to the second ejector flow channel 103. Herein, no specific limitation is made.

[0047] The second diverging section 1011 can be provided in plurality, and the plurality of second diverging sections 1011 are arranged at intervals along the height direction of the fire row 100. The flow area of each second diverging section 1011 can be gradually expanded towards the fire port 101a along the height direction of the fire row body 10. Adjacent two second diverging sections 1011 can be connected through the third air inlet section 1014. The flow area of each part of the third air inlet section 1014 in the height direction of the fire row body 10 can be substantially equal.

[0048] It can be understood that the second diverging section 1011 increases the flow area from the second ejector flow channel 103 to the fire port 101a, which can gradually reduce the mixed gas flow rate and increase the pressure. When the mixed gas passes through the second diverging section 1011 each time, the turbulence generated by the increase in flow area will further disturb the mixed gas of the fuel gas and air. After multiple alternating treatments, the mixed gas can achieve deep and uniform mixing before entering the fire port 101a, avoiding local high gas concentration and high combustion temperature leading to thermal nitrogen oxides. Moreover, after the mixed gas flow passes through the multiple alternating second diverging sections 1011, the gas flow velocity and pressure reaching the fire port 101a are more stable, preventing the gas flow from being too fast to cause flame fluctuation or too slow to cause backfire, and improving the combustion stability.

[0049] In addition, the mixing chamber 101 also has a third converging section 1012 and a first throat section 1013, the first throat section 1013 communicates the third converging section 1012 and the second diverging section 1011, and the third converging section 1012 communicates the second ejector flow channel 103. Among them, the flow area of the third converging section 1012 is gradually reduced from the second ejector flow channel 103 to the first throat section 1013, and the third converging section 1012 can be extended in the height direction of the fire row body 10 and towards the fire port 101a. It can be understood that the third converging section 1012 can be extended in the height direction of the fire row body 10 and towards the fire port 101a, while the second ejector flow channel 103 extends in the length direction of the fire row body 10, and the two cross each other. Therefore, when the gas flow changes direction from the second ejector flow channel 103 to the mixing chamber 101, the third converging section 1012 and the first throat section 1013 are arranged to accelerate the gas flow through the converging design of the third converging section 1012 and generate strong turbulence in the first throat section 1013 to disturb the mixed gas again, avoiding uneven distribution of the gas flow in the mixing chamber 101 due to sudden change of direction.

[0050] The technical scheme of the present application sets the fire grate 100 to include a fire grate body 10, sets the fire grate body 10 to have a mixing cavity 101, a first injection flow channel 102 and a second injection flow channel 103, sets the mixing cavity 101 to have a fire opening 101a for combustion, sets the first injection flow channel 102 to have a first injection opening 102a and an exhaust opening 102b, sets the second injection flow channel 103 to have a second injection opening 103a in communication with the exhaust opening 102b and the external environment, and the exhaust end of the second injection flow channel 103 is in communication with the mixing cavity 101, the first injection flow channel 102 is fed with gas and air through the first injection opening 102a, the second injection flow channel 103 is fed with air and gas from the exhaust opening 102b and air from the external environment through the second injection opening 103a, and thus air can be introduced multiple times through the first injection opening 102a and the second injection opening 103a, mixed with gas, the primary air coefficient of the fire grate 100 is improved, the overall high temperature when the fire opening 101a is combusted is avoided, and the mixing cavity 101 is set to have a second diverging section 1011 in communication with the fire opening 101a, the flow area of the second diverging section 1011 is set to increase from the second injection flow channel 103 to the fire opening 101a, so that the gas and air can be mixed multiple times through the first injection flow channel 102, the second injection flow channel 103 and the mixing cavity 101, the gas mixing uniformity is improved, the proportion of gas injected by each region of the fire opening 101a is more balanced, the combustion flame distribution of each region is more uniform, and the local high temperature combustion is avoided, so that the generation of thermal nitrogen oxides is greatly reduced, and the emission of harmful substances is reduced.

[0051] As shown in Figure 3 In an embodiment, the first injection flow channel 102 has a first converging section 1021 in communication with the exhaust opening 102b, and the flow area of the first converging section 1021 is set to decrease from the first injection opening 102a to the exhaust opening 102b.

[0052] The flow area of the first converging section 1021 can be set to taper from the first injection opening 102a to the exhaust opening 102b, and the exhaust opening 102b can be formed by the end edge position of the first converging section 1021. Alternatively, a third throat section 11 is further arranged between the first converging section 1021 and the exhaust opening 102b, and the flow area of the third throat section 11 is substantially equal to the flow area of the exhaust opening 102b.

[0053] Understandably, when the cross-sectional area of ​​the first tapering section 1021 is gradually reduced, the velocity of the gas-air mixture flowing from the first tapering section 1021 to the exhaust port 102b gradually increases, reaching its maximum at the exhaust port 102b, forming a high-speed, low-pressure zone. This allows more ambient air to be drawn in between the exhaust port 102b and the second ejector port 103a, supplementing the primary air and increasing the primary air coefficient. Furthermore, the gradual increase in velocity in the first tapering section 1021 enhances the disturbance between the gas and initial air, enabling them to mix initially and uniformly within the first tapering section 1021. The high-speed gas mixture exiting the exhaust port 102b forms a stable jet, providing a continuous and uniform airflow input to the second ejector channel 103.

[0054] like Figure 3 As shown, in one embodiment, the second ejector channel 103 has a second tapering section 1031, which is disposed near the second ejector port 103a. The flow cross-sectional area of ​​the second tapering section 1031 decreases from the second ejector port 103a toward the exhaust end of the second ejector channel 103.

[0055] The second ejector port 103a can be formed at the air inlet end of the second ejector channel 103, or the second ejector port 103a can be connected to the air inlet end of the second ejector channel 103 through the second air inlet section 1034. The flow cross-sectional area of ​​the second air inlet section 1034 can be approximately equal to the flow cross-sectional area of ​​the second ejector port 103a. The flow cross-sectional area of ​​the second tapering section 1031 can be gradually tapered from the second ejector port 103a to the exhaust end of the second ejector channel 103.

[0056] Understandably, when the second ejector channel 103 is positioned near the second ejector port 103a with a second tapering section 1031, while a high-speed jet is input into the second ejector channel 103 through the exhaust port 102b to draw in ambient air, the second tapering section 1031 accelerates the mixed airflow within the second ejector channel 103, creating a local low-pressure zone. This allows the second ejector port 103a to draw in more air from the ambient environment, further increasing the primary air coefficient. Furthermore, the acceleration of the mixed airflow by the second tapering section 1031 generates strong turbulent disturbances, ensuring thorough mixing of the air-fuel mixture from the first ejector channel 102 with the ambient air. This eliminates localized differences in fuel concentration, improves the uniformity of the mixture, and enhances the combustion uniformity of the combustion head, preventing excessively high local temperatures that could lead to the formation of large amounts of thermal nitrogen oxides.

[0057] And, the acceleration effect of the second tapered section 1031 can integrate the air from the external environment, the air from the first ejector flow channel 102 and the gas to be inhaled, so that the dispersed air flow is concentrated to form a stable continuous air flow, ensuring that the air flow input to the second ejector port 103a to the second ejector flow channel 103 is smooth and continuous, which is beneficial to the uniform combustion of the combustion head.

[0058] As shown in Figure 1 , Figure 3 in an embodiment, the first tapered section 1021 and the second tapered section 1031 are arranged along the first direction.

[0059] The first direction can be the length direction of the fire row body 10, and the combustion head at the fire opening 101a can have a plurality of fire holes arranged along the first direction. The exhaust port 102b and the second ejector port 103a can be arranged along the first direction, the exhaust port 102b can face the second ejector port 103a, and the flow area of the exhaust port 102b is smaller than the flow area of the second ejector port 103a.

[0060] It can be understood that when the first tapered section 1021 and the second tapered section 1031 are arranged along the first direction, the flow path of the air flow between the first tapered section 1021 and the second tapered section 1031 can be kept consistent without direction mutation, which can reduce the pressure loss of the air flow. The high-speed air flow discharged from the exhaust port 102b can be directly delivered to the second tapered section 1031, avoiding air flow dispersion and turning loss, thereby enhancing the ejecting effect of the second ejector port 103a, and further improving the air suction amount of the open air flow area. When the flow area of the exhaust port 102b is smaller than the flow area of the second ejector port 103a, the diameter of the exhaust port 102b is smaller than the diameter of the second ejector port 103a, which can avoid the air-gas mixture flow output from the exhaust port 102b to the external environment, so that the second ejector port 103a cannot concentrate the air flow from the first ejector flow channel 102.

[0061] And, the first ejector flow channel 102 can be arranged along the first direction as a whole, and the second ejector flow channel 103 can be arranged along the first direction as a whole near the second tapered section 1031, so that the flow paths of the air flow in the first ejector flow channel 102 and the second ejector flow channel 103 are basically consistent.

[0062] As shown in Figure 3 in an embodiment, the maximum flow area of the first tapered section 1021 is greater than the maximum flow area of the second tapered section 1031;

[0063] And / or, the minimum flow area of the first tapered section 1021 is smaller than the minimum flow area of the second tapered section 1031.

[0064] Understandably, when the maximum flow cross-sectional area of ​​the first tapering section 1021 is greater than that of the second tapering section 1031, the inlet cross-sectional area of ​​the first tapering section 1021 is relatively larger, which can accommodate more of the gas-air mixture entering the first ejector channel 102 from the first ejector port 102a, providing sufficient basic airflow for subsequent acceleration ejection. Setting the minimum flow cross-sectional area of ​​the first tapering section 1021 to be smaller than that of the second tapering section 1031 allows for a faster gas velocity at this location compared to other areas, facilitating the formation of a high-speed jet within the second ejector channel 103 to inject the gas mixture from the first ejector channel 102 into the second ejector channel 103. Furthermore, a faster airflow velocity at this location compared to other areas results in a stronger negative pressure, allowing the open airflow area to more effectively draw in air from the external environment, replenishing the primary air volume and improving the primary air coefficient.

[0065] Furthermore, when the minimum flow cross-sectional area of ​​the second tapering section 1031 is large, it can accommodate a larger flow rate of mixed gas after two air replenishments, avoiding excessive pressure loss or airflow turbulence due to an excessively small cross-section, while maintaining a suitable flow velocity and turbulence level to ensure deep mixing of the gas and air, providing a stable and uniform airflow for the mixing chamber 101.

[0066] In this way, a relay mechanism can be formed by the first tapering section 1021 and the second tapering section 1031, which first provides sufficient air intake and strong negative pressure injection, and then quickly converges and stabilizes the mixture. This ensures sufficient replenishment of primary air and achieves efficient and uniform mixing of the mixture, ultimately reducing the combustion temperature and avoiding local high-temperature areas, thereby reducing the generation of nitrogen oxides.

[0067] like Figure 5 , Figure 7 As shown, in one embodiment, the second tapering segment 1031 has two first inner wall surfaces 1031a disposed opposite to each other along a third direction, and two second inner wall surfaces 1031b disposed opposite to each other along a second direction. The two first inner wall surfaces 1031a and the two second inner wall surfaces 1031b enclose each other to form the second tapering segment 1031, and the second direction and the third direction intersect each other.

[0068] The second direction can be the width direction of the burner body 10, and the third direction can be the height direction of the burner body 10. Two first inner wall surfaces 1031a are spaced apart along the height direction of the burner body 10 and can extend along the length direction of the burner body 10. Two second inner wall surfaces 1031b are spaced apart along the width direction and can extend along the length direction of the burner body 10. Thus, the two first inner wall surfaces 1031a and the two second inner wall surfaces 1031b can enclose and form a second tapering section 1031 extending along the length direction of the burner body 10.

[0069] Optionally, in the direction from the second injection port 103a to the exhaust end of the second injection channel 103, the two second inner wall surfaces 1031b are arranged away from each other, and the two first inner wall surfaces 1031a are arranged close to each other.

[0070] In the direction from the second injection port 103a to the exhaust end of the second injection channel 103, it can be the first direction extending to the exhaust end of the second injection channel 103. In this direction, the cross-sectional area of the second converging section 1031 is arranged to be converging as a whole, when the two first inner wall surfaces 1031a are arranged close to each other and the two second inner wall surfaces 1031b are arranged away from each other, the second converging section 1031 is expanded in the width direction of the fire grate body 10, and the second converging section 1031 is converging in the height direction of the fire grate body 10.

[0071] In this way, the airflow can be accelerated in the height direction by arranging the two first inner wall surfaces 1031a close to each other, and the airflow can be diffused in the width direction by arranging the two second inner wall surfaces 1031b away from each other. The asymmetric cross-sectional change of the second converging section 1031 breaks the laminar flow state of the airflow, generates a complex three-dimensional turbulent flow field, promotes the deep mixing of the gas and air by improving the turbulent intensity, eliminates local concentration differences, avoids local high temperature caused by uneven mixture during combustion, and reduces the generation of nitrogen oxides.

[0072] The second injection channel 103 will be further introduced as follows, as shown in Figure 3 , Figure 4 , Figure 5 In an embodiment, the second injection channel 103 further has a second throat section 1032 and a first diverging section 1033, the second throat section 1032 communicates the second converging section 1031 and the first diverging section 1033, and the cross-sectional area of the first diverging section 1033 is arranged to increase from the second throat section 1032 to the exhaust end of the second injection channel 103.

[0073] It can be understood that the second throat section 1032, as the narrowest area in the second injection channel 103, receives the accelerated airflow of the second converging section 1031, always maintains the highest flow rate, and can continuously generate negative pressure, thereby increasing the injection capacity of the second converging section 1031 to the ambient air, ensuring the improvement of the primary air coefficient, and because the gas flow rate of the second throat section 1032 is relatively the fastest, strong turbulence can be formed, so that the mixed gas from the first injection channel 102 and the air from the ambient environment are disturbed violently, facilitating the mixing of the airflow.

[0074] The flow area of the first diverging section 1033 can gradually increase, so that the gas flow rate gradually decreases, the mixed gas has a longer mixing time in the first diverging section 1033, the gas and air are deeply mixed, the gas pressure gradually increases in the first diverging section 1033, and the mixed gas can be delivered to the mixing chamber 101 at a stable pressure, which is beneficial to the stable combustion of the combustion head and ensures the uniformity of the combustion flame.

[0075] As shown in the drawings, Figure 3 In an embodiment, the first injection channel 102 further has a first inlet section 1022 located between the first injection port 102a and the first converging section 1021 and communicating the first injection port 102a and the first converging section 1021.

[0076] The flow area of the first inlet section 1022 can be substantially equal to the flow area of the first injection port 102a, so that the gas flow can smoothly transition between the first injection port 102a and the first converging section 1021, buffer the instantaneous fluctuations of the gas flow at the first injection port 102a, and make the gas flow rate and pressure entering the first converging section 1021 more stable, so that the converging section can continuously and efficiently accelerate the gas flow to the exhaust port 102b, maintain the stability of the high-speed jet flow of the exhaust port 102b, enhance the injection capacity of the external air, and the like.

[0077] Continuing to refer to Figure 3 In an embodiment, the second injection channel 103 further has a second inlet section 1034 located between the second injection port 103a and the second converging section 1031 and communicating the second injection port 103a and the second converging section 1031.

[0078] The flow area of the second inlet section 1034 can be substantially equal to the flow area of the second injection port 103a. It can be understood that, in the case that the exhaust port 102b and the second injection port 103a are nested inside and outside each other and are located in the same plane, the airflow entering the second injection port 103a contains mixed gas from the exhaust port 102b of the first injection flow channel 102 and air from the external environment. By arranging the second inlet section 1034 between the second converging section 1031 and the second injection port 103a, the airflow of different sources can be uniformly mixed through molecular diffusion and turbulent flow in the second inlet section 1034 with stable flow area, which provides a basis for subsequent accelerated mixing in the second converging section 1031 and helps the mixing of subsequent gas. In addition, the airflow of the second injection port 103a can change instantaneously due to the fluctuation of the jet flow of the first injection flow channel 102 or the instability of the intake of external air. The arrangement of the second inlet section 1034 can buffer the fluctuation of the airflow, so that the flow rate and pressure of the airflow entering the second converging section 1031 are more stable, and the second converging section 1031 can continuously and efficiently complete the acceleration of the airflow.

[0079] As shown in Figure 3 , Figure 5 In an embodiment, the diameter of the exhaust port 102b is smaller than that of the second injection port 103a, and the exhaust port 102b and the second injection port 103a are nested inside and outside each other. Alternatively, the exhaust port 102b is located in the second injection flow channel 103.

[0080] It can be understood that, when the exhaust port 102b is nested in the second injection port 103a and the exhaust port 102b and the second injection port 103a are located in the same plane, the exhaust port 102b will not leak fuel gas to the external environment when the exhaust port 102b delivers fuel gas and air to the second injection flow channel 103 because the distance between the exhaust port 102b and the second injection flow channel 103 is close enough. Alternatively, the exhaust port 102b can be arranged in the second injection flow channel 103 to ensure that there is a gap between the first injection flow channel 12 and the second injection flow channel 103, so that the second injection port 103a can introduce air from the external environment, and the exhaust port 102b is located in the second injection flow channel 103. Therefore, when the exhaust port 102b delivers fuel gas and air to the second injection flow channel 103, the exhaust port 102b will not leak fuel gas to the external environment. When the exhaust port 102b is located in the second injection flow channel 103, the distance between the exhaust port 102b and the second injection port 103a can be set to be between 3 mm and 5 mm, so that the exhaust port 102b is located in the second inlet section 1034, and the exhaust port 102b does not extend too deep into the second injection port 103a, which can cause insufficient negative pressure near the second injection port 103a and difficulty in absorbing air from the external environment.

[0081] AsFigure 1 As shown in the embodiment, the outer surface of the first flow guide part 12 is further provided with a second flow guide surface, one end of the second flow guide surface is connected to the first flow guide surface 121, and the other end of the second flow guide surface is located in the second suction port 103a.

[0082] The second flow guide surface can be annularly arranged, and the second flow guide surface can form a third throat section 11 of the first suction flow channel 102 inside, and the exhaust port 102b can be arranged at one end of the third throat section 11 of the first suction flow channel 102 away from the first tapered section 1021.

[0083] As shown in the embodiment, the fire grate body 10 includes a first flow guide part 12 and a second flow guide part 13, the first flow guide part 12 is internally provided with the first suction flow channel 102, the second flow guide part 13 is internally provided with the second suction flow channel 103, and the first flow guide part 12 and the second flow guide part 13 are sequentially arranged along the first direction. Figure 1 The first flow guide part 12 can be two groups of sheet metal parts arranged along the width direction of the fire grate body 10, the two groups of sheet metal parts are spliced, and the first suction flow channel 102 is formed between the two groups of sheet metal parts. The second flow guide part 13 can also be two groups of sheet metal parts arranged along the width direction of the fire grate body 10, and the second suction flow channel 103 is formed by splicing the two groups of sheet metal parts. Alternatively, the fire grate body 10 is spliced by two sheet metals, and the first flow guide part 12 and the second flow guide part 13 can be formed by stamping the two sheet metals in a local area. The first flow guide part 12 and the second flow guide part 13 are sequentially arranged, which can be that the first flow guide part 12 and the second flow guide part 13 are spaced apart, or the first flow guide part 12 and the second flow guide part 13 are inlaid and nested, part of the first flow guide part 12 extends into the second flow guide part 13, that is, the exhaust port 102b is located in the second suction flow channel 103.

[0084] The first flow guide part 12 will be further introduced as follows, as shown in the embodiment, the outer surface of the first flow guide part 12 is provided with a first flow guide surface 121, the first flow guide surface 121 is used to guide the ambient air to flow to the second suction port 103a, and the first flow guide surface 121 is inclined from the outer periphery of the exhaust port 102b to the center of the exhaust port 102b in the extension direction towards the second suction port 103a.

[0085] Figure 1

[0086] ​​It can be understood that when the exhaust port 102b inputs the mixed gas to the second suction port 103a, the gas flow rate near the exhaust port 102b is the fastest in the open airflow area between the exhaust port 102b and the second suction port 103a, and the negative pressure formed in this area is greater, and the ambient air is more easily supplemented from this area to the second suction flow channel 103.

[0087] When the first flow guide part 12 is provided with the first flow guide surface 121, and the first flow guide surface 121 is inclined from the outer periphery of the exhaust port 102b to the center of the exhaust port 102b in the direction extending toward the second suction port 103a, the first flow guide surface 121 is tapered in the direction toward the second suction port 103a, guiding the air to flow along the tapered path, which can avoid air flow dispersion or vortex, reduce flow resistance, and make the air more smoothly enter the high-speed negative pressure area near the exhaust port 102b, ensuring that the ambient air in the open airflow area is efficiently supplemented from the second suction port 103a to the second suction flow channel 103. In addition, the inclination direction of the first flow guide surface 121 matches the jet direction of the exhaust port 102b, which can further amplify the negative pressure field in this area, enhance the suction force on the surrounding air, supplement more primary air, and improve the primary air coefficient.

[0088] The first flow guide surface 121 can form a guiding relay toward the second suction port 103a, guiding the external ambient air to flow obliquely toward the second suction port 103a, and the guiding path can match the flow path of the open airflow area, thereby greatly increasing the amount of air sucked by the second suction port 103a.

[0089] In addition, stable air supplement can reduce airflow fluctuations in the second suction flow channel 103, making the acceleration and mixing process of the mixed gas in the subsequent flow channel more stable, thereby realizing uniform combustion and avoiding the generation of a large amount of thermal nitrogen oxides caused by local high temperature.

[0090] The present application also provides a burner, which comprises the fire grate 100, and the specific structure of the fire grate 100 is referred to the above-mentioned embodiments. Since the burner adopts all the technical solutions of the above-mentioned embodiments, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here. The burner can further comprise a frame and a fan, and the fire grate 100 is arranged in the frame. The fire grate 100 can be arranged in multiple, and the multiple fire grates 100 can be arranged side by side. The fan can be arranged on the frame in an overlying manner to suck out the high-temperature flue gas generated by combustion.

[0091] The application further provides a water heater comprising the burner.

[0092] The above merely illustrates the embodiments of the present application, and is not intended to limit the protection scope of the present application. Any equivalent structure transformation based on the technical concept of the present application, or direct / indirect application in other related technical fields, which is made according to the content of the present application and the drawings, is included in the protection scope of the present application.

Claims

1. A fire grill, characterized in that, The device includes a burner body, which has a mixing chamber, a first ejector channel, and a second ejector channel. The mixing chamber is provided with a burner opening. The first ejector channel has a first ejector port at its air inlet end and an exhaust port at its air outlet end. The second ejector channel has a second ejector port at its air inlet end. The second ejector port is connected to the exhaust port and the external environment, respectively. The exhaust port of the second ejector channel is connected to the mixing chamber. The first ejector port is used to supply fuel gas and air to the first ejector channel. The second ejector port is used to supply air and fuel gas from the exhaust port to the second ejector channel, and to supply air from the external environment to the second ejector channel. The mixing chamber has a second gradually expanding section that connects to the ignition port, and the flow cross-sectional area of ​​the second gradually expanding section increases from the second ejector channel toward the ignition port. The first ejector channel has a first tapering section, which connects to the exhaust port, and the flow cross-sectional area of ​​the first tapering section decreases from the first ejector port to the exhaust port. The second ejector channel has a second tapering section, which is located close to the second ejector port. The flow cross-sectional area of ​​the second tapering section decreases from the second ejector port toward the exhaust end of the second ejector channel. The second tapering section has two first inner wall surfaces arranged opposite each other along a third direction, and two second inner wall surfaces arranged opposite each other along a second direction. The two first inner wall surfaces and the two second inner wall surfaces enclose the second tapering section, and the second direction and the third direction intersect each other. In the direction from the second ejector port to the exhaust end of the second ejector channel, the two second inner wall surfaces are arranged far apart from each other, and the two first inner wall surfaces are arranged close to each other.

2. The fire grill as described in claim 1, characterized in that, The first tapering segment and the second tapering segment are provided to extend along a first direction.

3. The fire grill as described in claim 1, characterized in that, The maximum flow cross-sectional area of ​​the first tapering section is greater than the maximum flow cross-sectional area of ​​the second tapering section. And / or, the minimum flow cross-sectional area of ​​the first tapering section is smaller than the minimum flow cross-sectional area of ​​the second tapering section.

4. The fire grill as described in claim 1, characterized in that, The second ejector channel also has a second throat and a first diverging section. The second throat connects the second contracting section and the first diverging section. The flow cross-sectional area of ​​the first diverging section increases from the second throat toward the exhaust end of the second ejector channel.

5. The fire grill as described in claim 1, characterized in that, The first ejector channel also has a first air intake section, which is located between the first ejector port and the first tapering section, and connects the first ejector port and the first tapering section. And / or, the second ejector channel further has a second air intake section, which is located between the second ejector port and the second tapering section and connects the second ejector port and the second tapering section.

6. The fire grill as described in claim 1, characterized in that, The fire briquette body includes a first drainage section and a second drainage section. The first drainage section has a first ejector channel inside, and the second drainage section has a second ejector channel inside. The first drainage section and the second drainage section are arranged sequentially along a first direction. The outer surface of the first drainage part is provided with a first guide surface, which is used to guide the ambient air to flow towards the second ejector. The first guide surface is inclined from the outer periphery of the exhaust port to the center of the exhaust port in the direction extending towards the second ejector.

7. The fire rack according to any one of claims 1 to 6, characterized in that, The diameter of the exhaust port is smaller than that of the second ejector port; The exhaust port is nested inside and outside the second ejector port, or the exhaust port is located inside the second ejector channel.

8. A burner, characterized in that, Includes the fire rack as described in any one of claims 1 to 7.

9. A water heater, characterized in that, Includes the burner as described in claim 8.

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