A fume hood assembly and water heater

Abstract

The utility model discloses a fume hood assembly and water heater, the fume hood assembly includes: the fume collection cover, the smoke guide pipe and the sound insulation smoke pipe, the upper end of smoke guide pipe is the closed end, and the lateral wall is equipped with a plurality of smoke outlet holes, and the lower end of smoke guide pipe is connected in the fume collection cover, and the sound insulation smoke pipe is located at the outer periphery of smoke guide pipe, and is connected in the fume collection cover, the utility model discloses the upper end of smoke guide pipe is the closed end, and the lateral wall is equipped with a plurality of smoke outlet holes, and the lower end is connected in the fume collection cover, and the sound insulation smoke pipe is located at the outer periphery of smoke guide pipe, when the smoke that fume collection cover gathers enters smoke guide pipe, will along with the smoke outlet hole enter the sound insulation smoke pipe and flow out, has changed the characteristic frequency of whole smoke emission system, has broken the inherent frequency condition of heat release pulsation and pressure pulsation mutual excitation through changing system characteristic frequency, makes both difficult to produce effective coupling effect, has suppressed the generation of helmholtz mode oscillation from the root, and further reduced the abnormal combustion noise that the heat sound oscillation has caused.

Description

Technical Field

[0001] This utility model relates to the field of water heater technology, and in particular to a fume hood assembly and a water heater. Background Technology

[0002] Gas water heaters are widely used in modern households for supplying hot water, and are favored by consumers for their advantages such as instant hot water and ease of use. However, in actual use, gas water heaters often experience abnormal combustion noise during the combustion phase, which not only affects the user experience but may also indicate potential operational safety hazards within the equipment.

[0003] During the combustion process of a gas water heater, its internal structure and combustion characteristics interact to form a complex acoustic-thermodynamic system. Research has found that the structural characteristics of a gas water heater allow it to be approximated as a double-necked Helmholtz resonator during combustion. A Helmholtz resonator is a structure with specific acoustic characteristics that easily undergoes Helmholtz modal oscillations when certain external conditions are met. In the special "double-necked Helmholtz resonator" structure of a gas water heater, the combustion process can trigger such modal oscillations.

[0004] The fundamental mechanism behind this oscillation lies in the coupling between heat release pulsations and pressure pulsations. During gas combustion, the flame is not stable and uniform, but rather exhibits periodic heat release pulsations. These heat release pulsations interact with and influence the pressure pulsations within the combustion chamber. Specifically, the flame's heat release process injects energy into the pressure oscillations, causing the amplitude of the pressure pulsations to continuously increase. As this energy injection continues, the pressure pulsations gradually intensify, ultimately manifesting as a thermoacoustic oscillation phenomenon.

[0005] Thermoacoustic oscillation can have many adverse effects. On the one hand, it can cause strong vibrations and noise inside the gas water heater, which can not only interfere with users' normal lives and reduce their satisfaction with the product, but also cause fatigue damage to the internal components of the gas water heater, shortening the service life of the equipment, and may even lead to more serious safety accidents such as gas leaks and explosions.

[0006] Currently, although the industry is aware of the problem of abnormal combustion noise in gas water heaters, in-depth research into its generation mechanism is still incomplete, and effective and targeted suppression methods are lacking. Most existing solutions only attempt to address the issue from a macroscopic perspective, such as optimizing burner structure and adjusting the gas-air mixing ratio, failing to fundamentally solve the problem of abnormal combustion noise caused by thermoacoustic oscillations. Therefore, in-depth research into the generation mechanism of thermoacoustic oscillations during gas water heater combustion and the development of effective suppression technologies are of significant practical importance for improving the performance of gas water heaters, enhancing user experience, and ensuring safety. Utility Model Content

[0007] The purpose of this utility model is to overcome the shortcomings of the prior art and provide a fume hood assembly and a water heater.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] In a first aspect, this utility model provides a smoke hood assembly, including: a smoke collection hood, a smoke guide pipe, and a soundproof smoke pipe. The upper end of the smoke guide pipe is a closed end, and the side wall is provided with a plurality of smoke outlet holes. The lower end of the smoke guide pipe is connected to the smoke collection hood. The soundproof smoke pipe is disposed on the outer periphery of the smoke guide pipe and connected to the smoke collection hood. Smoke gathered by the smoke collection hood enters the smoke guide pipe, and flows out along the smoke outlet holes into the soundproof smoke pipe.

[0010] In one specific embodiment, the smoke outlet is a circular hole.

[0011] In one specific embodiment, the diameter of the circular hole is greater than 8 mm, and the sum of the areas of all the circular holes is not less than 2826 square millimeters.

[0012] In one specific embodiment, the diameter of the smoke guide pipe is not less than 60 mm, and a ventilation area is formed between the soundproof smoke pipe and the smoke guide pipe, the area of ​​the ventilation area being not less than 2826 square millimeters.

[0013] In one specific embodiment, the top of the soundproof flue is provided with a smoke outlet, and the connection between the smoke outlet and the soundproof flue is inclined.

[0014] In one specific embodiment, the top of the smoke collection hood is provided with an annular protrusion, and the lower end of the smoke guide tube is connected to the annular protrusion.

[0015] In one specific embodiment, the closed end is a downwardly protruding conical end.

[0016] In one specific embodiment, the cone angle of the cone end ranges from 30 degrees to 60 degrees.

[0017] In one specific embodiment, a sealing gasket is also provided between the soundproof smoke pipe and the smoke collection hood.

[0018] The beneficial effects of this utility model's fume hood assembly compared to existing technologies are as follows: By setting the upper end of the smoke guide pipe as a closed end, providing several smoke outlet holes on the side wall, and connecting the lower end to the smoke collection hood, and placing the sound-insulating smoke pipe around the outer periphery of the smoke guide pipe and connecting it to the smoke collection hood, when the smoke gathered by the smoke collection hood enters the smoke guide pipe, it will flow out along the smoke outlet holes into the sound-insulating smoke pipe. This special smoke flow path design changes the characteristic frequency of the entire smoke emission system. By changing the system's characteristic frequency, the inherent frequency conditions of mutual excitation of heat release pulsation and pressure pulsation are successfully broken, making it difficult for the two to generate an effective coupling effect. In this way, the generation of Helmholtz mode oscillation is suppressed from the root, thereby significantly reducing abnormal combustion noise caused by thermoacoustic oscillation, significantly improving the acoustic environment during equipment operation, and improving the overall quietness of the machine.

[0019] Secondly, this utility model provides a water heater, including a fume hood assembly, a heat exchanger, and a combustion chamber as described above, wherein the combustion chamber and the fume hood are respectively connected to the front and rear ends of the heat exchanger.

[0020] Compared with existing technologies, the beneficial effects of this utility model water heater are as follows: By setting up a fume hood assembly and connecting the combustion chamber and the fume collection hood to the front and rear ends of the heat exchanger respectively, when the water heater is burning, the gathered smoke enters the flue pipe through the fume collection hood, then flows out along the smoke outlet into the soundproof flue pipe. This special smoke flow path design changes the characteristic frequency of the entire smoke emission system. By changing the system characteristic frequency, the inherent frequency condition of mutual excitation between heat release pulsation and pressure pulsation is successfully broken, making it difficult for the two to produce an effective coupling effect. In this way, the generation of Helmholtz mode oscillation is suppressed from the root, thereby significantly reducing abnormal combustion noise caused by thermoacoustic oscillation, significantly improving the acoustic environment of the water heater during operation, reducing combustion noise and heat exchange noise, and improving the overall quietness of the unit.

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model, 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of the fume hood assembly provided by this utility model;

[0024] Figure 2 A cross-sectional schematic diagram of the fume hood assembly provided by this utility model;

[0025] Figure 3 An exploded view of the fume hood assembly provided by this utility model;

[0026] Figure 4 A schematic diagram of the structure of the water heater provided by this utility model.

[0027] Figure label:

[0028] Smoke hood 10, annular protrusion 11, smoke guide pipe 20, closed end 21, smoke outlet 22, soundproof smoke pipe 30, smoke outlet 31, heat exchanger 40, combustion chamber 50. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0033] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0036] See Figures 1 to 3 As shown, this utility model discloses a specific embodiment of a smoke hood assembly, including: a smoke collection hood 10, a smoke guide pipe 20, and a soundproof smoke pipe 30. The upper end of the smoke guide pipe 20 is a closed end 21, and the side wall is provided with a plurality of smoke outlet holes 22. The lower end of the smoke guide pipe 20 is connected to the smoke collection hood 10. The soundproof smoke pipe 30 is disposed on the outer periphery of the smoke guide pipe 20 and connected to the smoke collection hood 10. The smoke gathered by the smoke collection hood 10 enters the smoke guide pipe 20, and flows into the soundproof smoke pipe 30 along the smoke outlet holes 22 and flows out.

[0037] Specifically, the smoke hood 10 is installed at a suitable position at the rear end of the gas water heater (or other smoke-generating equipment) to ensure that it completely covers the smoke area generated by the equipment, thus efficiently concentrating the smoke. The smoke hood 10 can be installed using common mechanical connection methods such as screw fixing or snap-fit ​​connection to ensure a secure installation and good seal between it and the equipment, preventing smoke leakage. The lower end of the smoke guide pipe 20 is connected to the smoke hood 10. During connection, sealing gaskets can be placed at the corresponding connection points between the lower end of the smoke guide pipe 20 and the smoke hood 10 to enhance sealing and prevent smoke from escaping from the connection. The smoke guide pipe 20 can be tightly fixed to the smoke hood 10 through welding, threaded connection, or flange connection to ensure smooth communication between the smoke guide pipe 20 and the internal space of the smoke hood 10. A soundproof smoke pipe 30 is fitted around the outer periphery of the smoke guide pipe 20, and its lower end is also connected to the smoke hood 10. The connection method between the soundproof flue 30 and the smoke hood 10 can be similar to that of the smoke guide 20, ensuring the stability and sealing of the connection. A certain gap should be maintained between the soundproof flue 30 and the smoke guide 20 to form an effective ventilation area.

[0038] When gas water heaters and other appliances start operating, the generated smoke rises under the influence of hot airflow and is quickly gathered by the smoke collection hood 10. The large-diameter design of the smoke collection hood 10 increases the smoke collection range and improves smoke collection efficiency. Under the influence of pressure difference, the smoke gathered inside the smoke collection hood 10 enters the smoke guide pipe 20 through the connection between the smoke collection hood 10 and the smoke guide pipe 20. Since the upper end 21 of the smoke guide pipe 20 is a closed end, the smoke can only flow outwards along several smoke outlet holes 22 provided on the side wall of the smoke guide pipe 20 into the space between the smoke guide pipe 20 and the soundproof smoke pipe 30. The size, number, and distribution of the smoke outlet holes 22 can be designed according to the actual smoke flow rate and system requirements to ensure that the smoke can flow out evenly and smoothly. The smoke entering the space between the soundproof smoke pipe 30 and the smoke guide pipe 20 continues to flow upwards along the soundproof smoke pipe 30 and is finally discharged from the outlet of the soundproof smoke pipe 30 to the outside or other designated areas.

[0039] In other words, by setting the upper end of the smoke guide pipe 20 as a closed end 21, providing several smoke outlet holes 22 on the side wall, and connecting the lower end to the smoke collection hood 10, and the soundproof smoke pipe 30 located on the outer periphery of the smoke guide pipe 20 and connected to the smoke collection hood 10, when the smoke gathered by the smoke collection hood 10 enters the smoke guide pipe 20, it will flow along the smoke outlet holes 22 into the soundproof smoke pipe 30 and out. This special smoke flow path design changes the characteristic frequency of the entire smoke emission system. By changing the system's characteristic frequency, the inherent frequency condition of mutual excitation of heat release pulsation and pressure pulsation is successfully broken, making it difficult for the two to produce an effective coupling effect. In this way, the generation of Helmholtz mode oscillation is suppressed from the root, thereby significantly reducing abnormal combustion noise caused by thermoacoustic oscillation, significantly improving the acoustic environment during equipment operation, and improving the overall quietness of the machine. In addition, abnormal combustion noise is often accompanied by strong vibrations inside the equipment, which can cause continuous fatigue damage to the internal components of the equipment. This fume hood assembly reduces the amplitude and frequency of vibrations during equipment operation by suppressing Helmholtz modal oscillations, thereby reducing wear and stress concentration on components caused by vibration. Therefore, it effectively extends the service life of internal components, reduces maintenance and replacement costs, and improves the overall reliability and stability of the equipment. Furthermore, Helmholtz modal oscillations not only cause noise and vibration problems but can also lead to more serious safety hazards. For example, strong vibrations may loosen gas pipeline connections, causing gas leaks; or cause poor contact in internal electrical components, increasing the risk of short circuits and fires. This fume hood assembly eliminates these potential safety hazards at the source by suppressing oscillations, providing users with a safer and more reliable operating environment and protecting their lives and property.

[0040] See Figures 2 to 3 As shown, in one embodiment, the smoke outlet 22 is a circular hole with a diameter greater than 8 mm.

[0041] Specifically, the water heater system can be viewed as a double-necked Helmholtz resonator. When heat release pulsations and pressure pulsations mutually excite each other, Helmholtz vibrations are generated, leading to vibration noise. The pressure pulsation period is inversely related to the characteristic frequency of the water heater system, i.e., pressure pulsation period = 1 / characteristic frequency of the water heater system. When the pressure pulsation period > hysteresis time, the system is prone to the phenomenon of heat release pulsations promoting pressure pulsations, causing the pressure pulsation amplitude to continuously increase, thus triggering abnormal vibration noise. By opening multiple circular smoke outlets 22 with a diameter greater than 8 mm on the flue pipe 20, the acoustic characteristics of the water heater system can be changed, increasing the system's characteristic frequency. When the system's characteristic frequency increases, the pressure pulsation period (pressure pulsation period = 1 / characteristic frequency of the water heater system) will change accordingly, thereby avoiding the situation where the pressure pulsation period > hysteresis time, effectively suppressing the phenomenon of heat release pulsations promoting pressure pulsations, and reducing abnormal vibration noise generated during water heater combustion. In addition, the porous structure has the effect of scattering and absorbing sound waves acoustically. When noise generated by the water heater during operation propagates to the smoke outlet 22 area of ​​the flue pipe 20, the sound waves undergo reflection, refraction, and interference between multiple smoke outlets 22, resulting in the dissipation and dispersion of some sound wave energy. Simultaneously, friction and vibration at the edges of the smoke outlets 22 convert some sound energy into heat or other forms of energy, thereby reducing the intensity of noise propagation. Furthermore, the circular smoke outlets 22 with a diameter greater than 8 mm provide a larger smoke passage area, reducing resistance within the flue pipe 20. The porous structure allows smoke to be evenly discharged from multiple directions, preventing localized smoke accumulation and ensuring smoother smoke emission. Additionally, the circular smoke outlet design reduces stress concentration, improving the structural strength of the flue pipe 20. Simultaneously, the porous structure helps reduce localized high temperatures and pressures, minimizing damage to the flue pipe 20 from thermal and mechanical stresses.

[0042] In one embodiment, the diameter of the smoke guide tube 20 is not less than 60 mm, and the sum of the areas of all the circular holes is not less than 2826 square millimeters.

[0043] Specifically, according to design requirements, the diameter of the flue pipe 20 should be no less than 60 mm. In actual production, based on the specific model, power, and expected smoke emission of the water heater, a suitable flue pipe 20 diameter is selected from the specification series that meets the standard of no less than 60 mm. For example, for water heaters with higher power and greater smoke emission, a flue pipe 20 with a diameter of 70 mm or 80 mm can be selected to ensure sufficient space for smoke flow. Furthermore, the flue pipe 20 is made of high-temperature resistant and corrosion-resistant materials, such as stainless steel. It is manufactured using processes such as pipe rolling and welding. During the pipe rolling process, the parameters of the rolling equipment are precisely controlled to ensure that the diameter of the flue pipe 20 meets the design requirements. During welding, the weld quality is ensured to prevent problems such as air leakage and deformation. Additionally, it is known that the total area of ​​all circular holes is no less than 2826 square millimeters. Assuming the circular holes are uniformly distributed, the diameter of the circular holes can be set first, and then the total area formula S = n × π × (d / 2) can be used. 2 (Where S is the total area, n is the number of circular holes, and d is the diameter of the circular holes), calculate the required number of circular holes. For example, if the diameter of the circular hole is set to 10 mm, then the area of ​​a single circular hole is π × (d / 2). 2 If the area is 78.5 square millimeters, then the minimum number of circular holes needed is n = 2826 / 78.5 = 36. The diameter and number of circular holes can be adjusted according to the actual situation, as long as the total area is not less than 2826 square millimeters.

[0044] In other words, the diameter of the flue pipe 20 is no less than 60 mm. Compared to flue pipes with smaller diameters, this provides a larger ventilation cross-section, reducing resistance to smoke flow within the flue pipe 20. This allows smoke to pass through the flue pipe 20 more smoothly, improving smoke emission efficiency, reducing the residence time of smoke inside the water heater, and decreasing the accumulation of oil and impurities within the flue pipe 20, thereby extending the water heater's lifespan. Furthermore, the total area of ​​all the circular holes is no less than 2826 square millimeters, which is no less than the ventilation area of ​​a standard φ60 mm diameter flue pipe, ensuring sufficient smoke emission capacity. During water heater combustion, this allows for timely exhaust of the generated smoke, avoiding problems such as backflow and incomplete combustion caused by insufficient ventilation area, thus improving the water heater's combustion and thermal efficiency. Additionally, the larger diameter of the flue pipe 20 and the sufficient ventilation area of ​​the circular holes make the smoke flow within the flue pipe 20 more stable, reducing airflow turbulence and disturbances. Stable airflow helps reduce noise and vibration caused by airflow impact and eddies, improving the smoothness and quietness of the water heater's operation. The porous structure effectively disperses pressure during smoke emission, preventing excessive localized pressure. As smoke exits through the circular orifices, pressure is evenly distributed, reducing vibration and noise caused by sudden pressure changes and further improving the water heater's acoustic performance. Furthermore, the design of the flue pipe 20's diameter and the total area of ​​the circular orifices adapts to the water heater's operational needs under varying power levels and environmental conditions. Whether operating under high or low loads, effective smoke emission is guaranteed, enhancing the water heater's adaptability and stability. The rational structural design and sufficient ventilation area reduce the risk of malfunctions caused by smoke accumulation and excessive pressure within the flue pipe 20, improving the water heater's reliability and safety, and lowering maintenance costs and operational risks.

[0045] See Figure 2 As shown, in one embodiment, a ventilation area is formed between the soundproof smoke pipe 30 and the smoke guide pipe 20, and the area of ​​the ventilation area is not less than 2826 square millimeters.

[0046] Specifically, firstly, it is determined that the diameter of the smoke guide duct 20 should not be less than 60 mm. Based on this, the inner diameter of the soundproof smoke duct 30 is designed. To ensure that the ventilation area is not less than 2826 square millimeters, it is assumed that the diameter of the smoke guide duct 20 is D1 (D1≥60 mm), and the inner diameter of the soundproof smoke duct 30 is D2. The ventilation area is annular, and its area formula is S=π×(D2 / 2). 2 -π×(D1 / 2) 2 For example, if the diameter of the smoke duct 20 is D1 = 60 mm, to ensure that the ventilation area S ≥ 2826 square millimeters, then π × (D2 / 2) 2 -π×(60 / 2) 2≥2826, solving the equation yields D2≥80 mm. Therefore, during the design phase, the minimum inner diameter of the soundproof flue 30 can be calculated using the above formula based on the actual diameter of the flue 20, ensuring that the ventilation area meets the requirements. The soundproof flue 30 is made of materials with good sound insulation properties, such as multi-layer composite sound insulation materials. Its outer layer can be metal to ensure strength, and the inner layer is a sound-absorbing material, such as fiberglass or polyester fiber, which can effectively absorb and reflect sound waves. The flue 20 is made of high-temperature resistant and corrosion-resistant metal materials, such as stainless steel, to withstand the high temperatures and smoke corrosion generated during the operation of the water heater.

[0047] In other words, because a closed or relatively closed ventilation area is formed between the soundproof flue 30 and the flue 20, the smoke, after being discharged from the flue 20, is confined within a certain space by the soundproof flue 30 and flows upward along the ventilation area, effectively preventing the smoke from dissipating into the surrounding environment. This not only improves the efficiency of smoke emission but also reduces pollution to the indoor environment. Furthermore, a sufficient ventilation area (not less than 2826 square millimeters) ensures that the smoke has enough space to flow, avoiding the problems of smoke accumulation and poor emission caused by an insufficient ventilation area. During high-load operation of the water heater, the smoke generated by combustion can be discharged in a timely manner, ensuring the normal operation of the water heater. Additionally, the ventilation area between the soundproof flue 30 and the flue 20 increases the noise propagation path. Combustion noise generated by gas combustion in the combustion chamber and heat exchange noise generated by heat exchange in the heat exchanger undergo multiple reflections, refractions, and absorptions within the ventilation area during propagation. Sound waves continuously interact with the inner wall of the soundproof flue 30 and the outer wall of the flue 20 during propagation, gradually consuming energy and thus reducing the intensity of noise propagation. The sound-absorbing material used in the soundproof flue 30 effectively absorbs and reflects sound waves. When noise propagates to the inner wall of the soundproof flue 30, the sound-absorbing material absorbs some of the sound wave energy, converting the sound energy into heat energy and other forms of energy. Simultaneously, the reflection effect of the multi-layer composite material causes the sound waves to attenuate continuously during propagation, further reducing the noise level transmitted from the exhaust pipe. Furthermore, the reasonable ventilation area design and the structure of the soundproof flue 30 can adapt to the operating needs of the water heater under different power and environmental conditions. Whether operating under high or low load, it ensures effective smoke discharge and effective noise reduction, improving the adaptability and stability of the water heater. In addition, the good ventilation and sound insulation structure reduces the risk of malfunctions caused by smoke accumulation and excessive noise, extending the service life of the water heater and reducing maintenance costs and usage risks.

[0048] See Figures 1 to 4 As shown, in one embodiment, the top of the soundproof smoke pipe 30 is provided with a smoke outlet 31, and the connection between the smoke outlet 31 and the soundproof smoke pipe 30 is inclined.

[0049] Specifically, the connection between the smoke outlet 31 and the soundproof smoke pipe 30 is inclined, which can better guide and concentrate the gas discharged from the smoke guide pipe 20, and then discharge it through the smoke outlet 31. Preferably, the smoke outlet 31 and the soundproof smoke pipe 30 are integrally formed, which has high strength and is easy to manufacture.

[0050] See Figures 2 to 3 As shown, in one embodiment, the top of the smoke collection hood 10 is provided with an annular protrusion 11, and the lower end of the smoke guide pipe 20 is connected to the annular protrusion 11.

[0051] Specifically, based on factors such as the overall dimensions of the water heater, the flue gas volume, and the installation space, the shape and size of the smoke collection hood 10 and the dimensions of the annular protrusion 11 are designed. The height of the annular protrusion 11 is typically set between 8-18 mm, and its outer diameter is slightly smaller than the inner diameter of the lower end of the flue pipe 20, generally 2-4 mm smaller, to ensure it can be smoothly fitted into the inner side of the lower end of the flue pipe 20 while ensuring a tight connection. Furthermore, external threads are machined on the outer wall of the annular protrusion 11, and internal threads are machined on the lower end of the flue pipe 20. The flue pipe 20 and the annular protrusion 11 are connected together by the engagement of the threads. Threaded connections offer advantages such as strong connections and easy disassembly, facilitating subsequent maintenance and repair. Flanges are installed at the lower ends of the annular protrusion 11 and the flue pipe 20, respectively, and the two flanges are connected together using bolts and nuts. Flange connections are suitable for larger diameter flue pipes 20, capable of withstanding greater pressure and torque, and offer high connection reliability. For applications requiring high sealing performance, welding connections can be used. Align the lower end of the smoke guide pipe 20 with the annular protrusion 11, and then weld the two together using a suitable welding method (such as argon arc welding). Welded connections have the advantages of good sealing and high connection strength, but disassembly after welding is relatively difficult.

[0052] In other words, the connection between the annular protrusion 11 and the lower end of the flue pipe 20 effectively improves the sealing performance of the connection. Threaded connections, through the tight fit of the threads and the action of sealant, prevent smoke leakage from the connection; flange connections achieve reliable sealing through the tightening force of gaskets and bolts; and welded connections form a completely sealed structure through the fusion of metals. This excellent sealing performance ensures that all smoke can be discharged through the flue pipe 20, reducing smoke pollution to the indoor environment. Furthermore, the improved sealing performance reduces smoke leakage and eddy currents at the connection, lowers the resistance to smoke emission, and improves smoke emission efficiency. This results in more complete combustion of the water heater, improved thermal efficiency, and reduced energy loss due to smoke leakage. Additionally, the design of the annular protrusion 11 guides and gathers the smoke discharged from the combustion chamber or heat exchanger. When smoke encounters the annular protrusion 11, it flows upward along the inner wall of the protrusion and enters the flue pipe 20, preventing smoke diffusion and turbulence within the smoke collection hood 10, thus ensuring smoother smoke emission. The well-designed annular protrusion 11 reduces airflow turbulence during smoke emission. Stable airflow helps reduce noise and vibration caused by airflow impact and eddies, improving the smoothness and quietness of the water heater's operation. Furthermore, the annular protrusion 11 provides accurate positioning and support for the flue pipe 20. During installation, the flue pipe 20 can be easily connected to the annular protrusion 11, ensuring accurate installation. Simultaneously, the annular protrusion 11 can withstand the weight of the flue pipe 20 and the pressure generated during smoke emission, improving the structural stability of the entire smoke exhaust system.

[0053] In one embodiment, the closed end 21 is a downwardly protruding conical end.

[0054] Specifically, the cone angle at the end of the flue gas system is determined based on factors such as flow rate, pressure, and overall structural space. Generally, a cone angle between 30 and 60 degrees is suitable. A smaller cone angle can guide the smoke flow more smoothly, but may increase the length of the cone end; a larger cone angle can shorten the length of the cone end, but may result in less smooth smoke flow guidance. Computational fluid dynamics (CFD) simulations are used to analyze the smoke flow under different cone angles to select a cone angle that effectively reduces exhaust resistance, turbulence, and vortices while conforming to the overall structural layout of the water heater.

[0055] In other words, the downward-protruding conical end design allows for a smooth transition of smoke as it enters the soundproof flue 30 from the flue 20. Compared to straight or abrupt end designs, the sloping structure of the conical end guides the smoke to gradually accelerate and change its flow direction, avoiding local pressure loss caused by abrupt changes in cross-section, thereby reducing exhaust resistance. The shape of the conical end allows for uniform distribution of smoke during flow, reducing local resistance increases caused by uneven airflow distribution and improving exhaust smoothness. Furthermore, the conical end shape guides the smoke to flow in a predetermined direction, reducing disordered airflow within the exhaust pipe. Turbulence and vortices often lead to energy loss and increased noise, while the conical end design effectively reduces these adverse effects by optimizing the airflow path. Reducing turbulence and vortices means reducing energy loss during smoke flow, making the exhaust system more efficient. This not only improves exhaust efficiency but also reduces the energy consumption of the water heater. Additionally, due to the reduced exhaust resistance and the decrease in turbulence and vortices, smoke can be discharged more quickly through the exhaust system, increasing exhaust speed. Efficient smoke extraction ensures that combustion smoke is discharged promptly, preventing smoke accumulation inside the water heater and guaranteeing complete and stable combustion, thereby improving the water heater's thermal efficiency. Furthermore, reduced turbulence and vortices decrease the impact and friction of airflow within the exhaust pipe, thus reducing noise. The conical end design makes the smoke flow smoother, reducing noise sources caused by airflow turbulence.

[0056] In one embodiment, a sealing gasket is also provided between the soundproof smoke pipe 30 and the smoke collection hood 10.

[0057] Specifically, sealing gaskets can be made of rubber, such as nitrile rubber, which has good oil resistance, wear resistance, and aging resistance. It is suitable for general water heater exhaust environments and can effectively withstand small amounts of oil and temperature changes that may occur during exhaust. Its operating temperature range is typically between -30℃ and 120℃, meeting the exhaust requirements of most household water heaters. Alternatively, silicone gaskets can be used: they have excellent high-temperature resistance, with an operating temperature range of -60℃ to 250℃, and good chemical stability, exhibiting good resistance to various chemicals. If the water heater exhaust temperature is high or corrosive substances are present in the exhaust environment, silicone sealing gaskets are a better choice. Fluororubber gaskets can also be used: they have excellent high-temperature resistance, corrosion resistance, and oil resistance, suitable for high-temperature, high-pressure, and highly corrosive exhaust environments, such as some industrial water heaters or exhaust systems under special conditions.

[0058] In other words, the sealing gasket fills the tiny gap between the soundproof flue 30 and the smoke collection hood 10, preventing smoke from leaking from the connection. During the operation of the water heater, the smoke produced by combustion contains a large number of harmful substances, such as carbon monoxide and nitrogen oxides. If this smoke leaks into the room, it will cause serious harm to human health. The use of the sealing gasket effectively reduces the risk of smoke leakage and ensures indoor air quality. Good sealing performance can prevent outside air from entering the smoke exhaust system, avoiding problems such as poor smoke exhaust and unstable combustion caused by air entering. At the same time, it can also reduce pressure fluctuations inside the smoke exhaust system, improving the stability and reliability of the entire smoke exhaust system. In addition, the soundproof flue 30 itself has a certain sound insulation effect, but if the connection is not sealed tightly, the airflow noise generated during smoke exhaust may leak out from the gap. The sealing gasket can effectively prevent the leakage of airflow noise, enhance the sound insulation performance of the soundproof flue 30, and reduce the impact of smoke exhaust noise on the indoor environment. During the operation of the water heater, the smoke exhaust system may vibrate, and the vibration will be transmitted to the surrounding structure through the connection, generating noise. Sealing gaskets possess a certain degree of elasticity, serving as a buffer and vibration damper to reduce the transmission of vibration noise and further lower exhaust noise. Additionally, they prevent external moisture, dust, and corrosive substances from entering the exhaust system, reducing corrosion of the soundproof flue 30 and smoke hood 10. Exhaust systems operate in high-temperature, humid environments and are susceptible to corrosion; the use of sealing gaskets effectively extends equipment lifespan and reduces maintenance and replacement costs. Good sealing performance reduces wear on connection points caused by airflow impact and vibration within the exhaust system, protecting the connection structure of the soundproof flue 30 and smoke hood 10 and ensuring normal equipment operation.

[0059] See Figure 4 As shown, this utility model also discloses a water heater, including the fume hood assembly, heat exchanger 40 and combustion chamber 50 as described above, wherein the combustion chamber 50 and the fume hood 10 are respectively connected to the front and rear ends of the heat exchanger 40.

[0060] Specifically, the installation position of the heat exchanger 40 inside the water heater is determined based on the overall structure and design requirements of the water heater. Typically, the heat exchanger 40 is installed in a relatively central and stable area inside the water heater to ensure it can withstand the pressure and vibration from subsequent connecting components. Suitable fixing devices, such as bolts and brackets, are used to securely install the heat exchanger 40 onto the water heater casing. During installation, the horizontal and vertical alignment of the heat exchanger 40 must be ensured to avoid affecting the connection of subsequent components and the performance of the water heater due to installation deviations. The combustion chamber 50 is connected to the front end of the heat exchanger 40 via a flange connection or welding. If a flange connection is used, first install the corresponding flange at the connection point between the combustion chamber 50 and the heat exchanger 40, then place a sealing gasket between the flanges, and finally tighten the two flanges together with bolts to ensure a tight connection and prevent leakage of combustion gases. If welding is used, appropriate welding processes and materials must be selected to ensure welding quality, making the combustion chamber 50 and the heat exchanger 40 a single unit. The fume hood 10 is installed at the rear end of the heat exchanger 40, ensuring that its opening completely covers the exhaust port of the heat exchanger 40 to effectively collect the smoke generated after combustion. The connection between the fume hood 10 and the rear end of the heat exchanger 40 is similar to the connection between the combustion chamber 50 and the heat exchanger 40, and can be achieved using a flange connection or welding. During the connection process, care must be taken to ensure the airtightness between the fume hood 10 and the heat exchanger 40 to prevent smoke leakage. Simultaneously, the angle and position of the fume hood 10 should be adjusted to ensure smooth connection with other exhaust components such as the soundproof flue 30.

[0061] In other words, Helmholtz modal oscillation is a resonance phenomenon that occurs at a specific frequency due to the interaction of acoustics and hydrodynamics. In water heaters, if the heat release and pressure pulsations generated by combustion match the system's characteristic frequency, Helmholtz modal oscillations can be triggered, leading to abnormal vibrations and noise in the system. By increasing the characteristic frequency of the water heater system and decoupling it from the heat release and pressure pulsations, the conditions for oscillation generation are disrupted, thus effectively preventing the occurrence of Helmholtz modal oscillations. By setting up a fume hood assembly and connecting the combustion chamber 50 and the fume hood 10 to the front and rear ends of the heat exchanger 40 respectively, when the water heater is burning, the gathered smoke enters the flue pipe 20 through the fume hood 10, then flows out along the smoke outlet 22 into the soundproof flue pipe 30. This special smoke flow path design changes the characteristic frequency of the entire smoke emission system. By changing the system's characteristic frequency, the inherent frequency conditions of mutual excitation between heat release pulsation and pressure pulsation are successfully broken, making it difficult for the two to generate an effective coupling effect. In this way, the generation of Helmholtz mode oscillation is suppressed from the root, thereby significantly reducing abnormal combustion noise caused by thermoacoustic oscillation, significantly improving the acoustic environment during water heater operation, reducing combustion noise and heat exchange noise, and improving the overall quietness of the unit.

[0062] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this technical solution are within the protection scope of this utility model.

Claims

1. A smoke hood assembly, characterized in that, include: The system includes a smoke hood, a smoke guide pipe, and a soundproof smoke pipe. The upper end of the smoke guide pipe is closed, and its side wall has several smoke outlet holes. The lower end of the smoke guide pipe is connected to the smoke hood. The soundproof smoke pipe is located on the outer periphery of the smoke guide pipe and is connected to the smoke hood. The smoke gathered by the smoke hood enters the smoke guide pipe, flows through the smoke outlet holes into the soundproof smoke pipe, and then flows out.

2. The smoke hood assembly according to claim 1, characterized in that, The smoke outlet is a circular hole.

3. The smoke hood assembly according to claim 2, characterized in that, The diameter of the circular hole is greater than 8 mm, and the sum of the areas of all the circular holes is not less than 2826 square millimeters.

4. The smoke hood assembly according to claim 1, characterized in that, The diameter of the smoke guide pipe is not less than 60 mm, and a ventilation area is formed between the soundproof smoke pipe and the smoke guide pipe, the area of ​​which is not less than 2826 square millimeters.

5. The smoke hood assembly according to claim 1, characterized in that, The top of the soundproof flue is provided with a smoke outlet, and the connection between the smoke outlet and the soundproof flue is inclined.

6. The smoke hood assembly according to claim 1, characterized in that, The top of the smoke collection hood is provided with an annular protrusion, and the lower end of the smoke guide tube is connected to the annular protrusion.

7. The smoke hood assembly according to claim 1, characterized in that, The closed end is a downward-protruding conical end.

8. The smoke hood assembly according to claim 7, characterized in that, The cone angle at the end of the cone ranges from 30 degrees to 60 degrees.

9. The smoke hood assembly according to claim 1, characterized in that, A sealing gasket is also provided between the soundproof smoke pipe and the smoke collection hood.

10. A water heater, characterized in that, It includes the fume hood assembly, heat exchanger, and combustion chamber as described in any one of claims 1-9, wherein the combustion chamber and the fume hood are respectively connected to the front and rear ends of the heat exchanger.

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