Premixing unit, fan cover, fan assembly and gas water heater

Abstract

This invention relates to gas water heater devices and discloses a premixing device, including an outer cylinder (1) and an inner cylinder (2). The outer cylinder (1) is fitted onto the inner cylinder (2) to form an integral double-layer cylindrical structure, and the spacer between the two forms a first air inlet channel (3). An air inlet connector (5) is integrally connected to the outer cylinder (1), and the air inlet direction of the air inlet connector (5) is perpendicular to the axial direction of the first air inlet channel (3). The air inlet connector (5) is positioned directly opposite the cylinder wall of the inner cylinder (2). The cylinder cavity of the inner cylinder (2) forms a second air inlet channel (21), and the air outlets of the first air inlet channel (3) and the second air inlet channel (21) are interconnected. This invention also discloses a fan cover, a fan assembly, and a gas water heater. The premixing device of this invention has a simple structure, is easy to install, effectively prevents gas leakage, and reduces material management costs.

Description

Technical Field

[0001] This invention relates to gas water heater devices, specifically to a premixing device, and also to a fan cover, a fan assembly, and a gas water heater. Background Technology

[0002] In gas water heaters, the effectiveness of air-gas mixing directly affects whether the mixture can burn completely, which in turn has a decisive impact on the level of harmful gases emitted from the exhaust gas.

[0003] In existing technologies, premixed combustion technology is widely used. Premixed combustion refers to the process where the fuel gas is fully mixed with air before combustion in the burner, eliminating the need for additional air supply during combustion. Premixed combustion offers advantages such as high combustion intensity, short flame, and low combustion noise.

[0004] Therefore, a mixing device is needed to ensure thorough mixing of gas and air in a gas water heater, achieving combustion under different loads by adjusting the intake air volume and airflow. Currently, such as Figure 1 and Figure 2 As shown, a venturi tube is typically used to connect the air and fuel gas to the premixing connector 1a for initial mixing. However, this method results in a complex structure, numerous parts, and cumbersome installation, increasing material management costs and reducing installation efficiency. Furthermore, it often leads to uneven mixing of the fuel gas and air, resulting in incomplete combustion of the fuel gas in the combustion chamber, causing fuel waste and pollution emissions.

[0005] To address the problem of uneven mixing of fuel gas and air, existing technologies provide a method such as... Figure 3The gas mixer shown includes a hollow mixer housing 1' with a gas inlet 4', an air inlet 10' at one end and a mixed gas outlet 11' at the other end. The mixer housing 1' contains an annular outer cavity housing 2' and an annular inner cavity housing 3'. The outer cavity housing 2' is located between the mixer housing 1' and the inner cavity housing 3', and an outer cavity 7' is formed between the outer cavity housing 2' and the mixer housing 1'. The gas inlet 4'... The inner cavity 8' is formed between the outer cavity 3' and the outer cavity 2' and is connected to the outer cavity 7'. The outer cavity 2' is provided with an inner cavity gas inlet 5' that connects the outer cavity 7' and the inner cavity 8'. The inner cavity 3' surrounds the mixing chamber 12'. The air inlet 10' and the mixing outlet 11' are connected to the mixing chamber 12'. The inner cavity 3' is circumferentially distributed with a plurality of first mixing chamber gas inlets 61' and second mixing chamber gas inlets 62' that connect the inner cavity 8' and the mixing chamber 12'. Because the mixer housing has an annular outer cavity and an annular inner cavity, with the outer cavity spaced apart from the mixer housing to form the outer cavity, and the inner cavity spaced apart from the outer cavity to form the inner cavity, forming a mixing chamber, the gas from the gas inlet first enters the outer cavity, then from the outer cavity into the inner cavity, and finally into the mixing chamber. The pressure of the gas decreases in the inner and outer cavities, resulting in a uniform distribution of the gas in the inner cavity and equal pressure throughout. This allows the gas to enter the mixing chamber evenly, distribute uniformly within it, and mix evenly with the air. However, this gas mixer has a complex structure, significantly increasing production costs.

[0006] In view of the above-mentioned shortcomings of the existing technology, there is a need to design a new type of premixing device. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a premixing device that has a simplified structure while ensuring uniform mixing of air and fuel gas, thereby reducing material management costs.

[0008] A further technical problem to be solved by the present invention is to provide a fan cover that is easier to install.

[0009] A further technical problem to be solved by the present invention is to provide a fan assembly that can ensure that the gas and air are fully mixed.

[0010] Furthermore, the technical problem to be solved by the present invention is to provide a gas water heater that can reduce the content of harmful gases in exhaust emissions.

[0011] To address the aforementioned technical problems, the first aspect of the present invention provides a premixing device, comprising an outer cylinder and an inner cylinder. The outer cylinder is fitted onto the inner cylinder to form an integral double-layer cylindrical structure, and the spacer between the two forms a first air intake channel. An air intake connector is integrally connected to the outer cylinder, the air intake direction of the air intake connector being perpendicular to the axial direction of the first air intake channel, and the air intake connector being disposed directly opposite the cylinder wall of the inner cylinder. The cylinder cavity of the inner cylinder forms a second air intake channel, and the air outlets of the first air intake channel and the second air intake channel are interconnected.

[0012] Preferably, it also includes a pressure tapping structure for detecting the pressure inside the inner cylinder.

[0013] Specifically, the pressure tapping structure includes a detection channel that passes through the outer cylinder and the inner cylinder and is in communication with the inner cylinder.

[0014] More specifically, the pressure tapping structure further includes a pressure tapping channel located inside the inner cylinder and parallel to the inner wall of the inner cylinder, and the detection channel is connected to the pressure tapping channel to form a bent structure.

[0015] Furthermore, the pressure tapping structure is located adjacent to the air inlet of the second air intake channel.

[0016] Preferably, the outer cylinder, the inner cylinder, and the pressure tapping structure are cast as a single integral part.

[0017] Preferably, the first air intake channel and the second air intake channel are arranged in parallel.

[0018] Preferably, the wall of the air outlet of the outer cylinder extends beyond the wall of the air outlet of the inner cylinder.

[0019] Preferably, the edge of the air inlet of the inner cylinder is connected to the outer cylinder to form a first flange.

[0020] Typically, an air inlet grille is installed on the first flange.

[0021] More preferably, the air outlet end of the outer cylinder is provided with a second flange along the circumferential direction.

[0022] A second aspect of the present invention provides a fan cover plate, comprising a premixing device and a cover plate as described in any one of the first aspects of the technical solution above, wherein the air outlet of the outer cylinder is sealed to a through hole on the cover plate.

[0023] Preferably, the premixing device and the cover plate are cast as a single piece.

[0024] A third aspect of the present invention provides a fan assembly, comprising a fan cover plate and a fan assembly as described in any one of the second aspects of the technical solutions above, wherein the premixing device is mounted on the fan assembly via the cover plate.

[0025] Typically, the fan assembly includes a volute housing and a fan mounted on the volute housing, with a cover plate connected to the volute housing to form a cavity, and the second air intake channel and the first air intake channel respectively communicating with the cavity.

[0026] A fourth aspect of the present invention provides a gas water heater, including the fan assembly described in any one of the third aspects of the technical solution above.

[0027] The beneficial effects of the present invention through the above technical solution are as follows:

[0028] The premixing device of the present invention has a double-layer cylindrical structure. The outlets of the first and second air inlet channels are connected to each other, so that air and gas can be well mixed at the outlets of both channels. Specifically, the second air inlet channel can generally be selected as the air inlet channel, and the gas enters the first air inlet channel through the air inlet connector. Since the air inlet direction of the air inlet connector is perpendicular to the axial direction of the first air inlet channel and the air inlet connector is set directly opposite the inner cylinder wall, the inner cylinder wall can disperse the gas, making the gas more evenly distributed in the annular space formed by the first air inlet channel, and promoting the full mixing of air and gas at the outlets of the first and second air inlet channels. Moreover, the air inlet connector, outer cylinder and inner cylinder are integrated into one unit, which helps to reduce the amount of materials in the production process and reduce material management costs. The overall structure is relatively simple.

[0029] Furthermore, the edge of the air inlet of the inner cylinder is connected to the outer cylinder to form a first flange, which closes this end of the outer cylinder. Through this structural design, the gas can only flow to the air outlet, preventing gas leakage and providing a high level of safety.

[0030] The fan cover plate of the present invention, by setting the premixing device and the cover plate as a cast integral part, can further reduce the amount of materials, reduce material management costs, improve installation efficiency, and, with no connecting gaps, effectively prevent gas leakage and improve equipment safety.

[0031] The premixing device described above can be conveniently installed on the fan assembly of the present invention through a cover plate. Since the premixing device is located at the front of the fan, the air and gas are mixed once at the outlet of the premixing device, and then mixed again by the fan, so that the air and gas are more fully mixed and the emission of harmful gases is reduced.

[0032] Other advantages of the present invention and the technical effects of preferred embodiments will be further described in the following detailed description. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a hybrid device in the prior art;

[0034] Figure 2 This is a schematic diagram of the longitudinal cross-sectional structure of a hybrid device in the prior art;

[0035] Figure 3 This is a schematic diagram of the structure of a gas mixer in the prior art;

[0036] Figure 4 This is a partial cross-sectional view of a premixing device according to a first specific embodiment of the present invention, wherein the premixing device is connected to a cover plate.

[0037] Figure 5 This is one of the structural schematic diagrams of the fan cover plate according to the second specific embodiment of the present invention;

[0038] Figure 6 This is the second schematic diagram of the structure of the fan cover plate according to the second specific embodiment of the present invention;

[0039] Figure 7 This is the third structural schematic diagram of the fan cover plate according to the second specific embodiment of the present invention;

[0040] Figure 8 This is the fourth structural schematic diagram of the fan cover plate according to the second specific embodiment of the present invention;

[0041] Figure 9 This is a three-dimensional structural schematic diagram of the premixing device according to the third specific embodiment of the present invention;

[0042] Figure 10 yes Figure 9 A partial sectional view;

[0043] Figure 11 This is a front view of the premixing device according to the third specific embodiment of the present invention;

[0044] Figure 12 yes Figure 11 A bottom view;

[0045] Figure 13 yes Figure 11 The left view;

[0046] Figure 14 yes Figure 11 Longitudinal cross-section;

[0047] Figure 15 This is a three-dimensional assembly drawing of the fan assembly according to a specific embodiment of the present invention;

[0048] Figure 16 This is a three-dimensional structural diagram of the fan assembly according to a specific embodiment of the present invention.

[0049] Explanation of reference numerals in the attached figures

[0050] 1 outer cylinder 2 inner cylinder

[0051] 21 Second intake channel 3 First intake channel

[0052] 41 Detection channel 42 Pressure tapping channel

[0053] 5. Intake connector 6. Cover plate

[0054] 71 volute casing 72 fan

[0055] 8 First flange 9 Second flange

[0056] 1a Premix connector 1' Mixer housing

[0057] 2' Outer shell 3' Inner shell

[0058] 4' Gas inlet 5' Inner cavity gas inlet

[0059] 61' First mixing chamber gas inlet 62' Second mixing chamber gas inlet

[0060] 7' External cavity 8' Internal cavity

[0061] 10' Air inlet 11' Mixed gas outlet

[0062] 12' Mixing Gas Chamber Detailed Implementation

[0063] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0064] 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0065] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral 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 invention according to the specific circumstances.

[0066] It should be understood that, for ease of description and simplification, the terms "air inlet," "air outlet," "outer," and "inner" are based on the premixing device itself. For example, the air inlet mesh is installed at the air inlet of the inner cylinder 2, and the other end of the inner cylinder 2 is the air outlet. The surface of the outer cylinder 1 connected to the cover plate 6 is the outer, and the opposite surface of the outer cylinder 1 is the inner. The terms are based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Moreover, the orientation terms for the premixing device of the present invention should be understood in conjunction with the actual installation state.

[0067] like Figures 4 to 14 As shown, the premixing device of the basic embodiment of the present invention includes an outer cylinder 1 and an inner cylinder 2. The outer cylinder 1 is fitted onto the inner cylinder 2 to form an integral double-layer cylindrical structure, and the spacer between the two forms a first air intake channel 3. An air intake connector 5 is integrally connected to the outer cylinder 1. The air intake direction of the air intake connector 5 is perpendicular to the axial direction of the first air intake channel 3, and the air intake connector 5 is positioned directly opposite the cylinder wall of the inner cylinder 2. The cylinder cavity of the inner cylinder 2 forms a second air intake channel 21, and the air outlets of the first air intake channel 3 and the second air intake channel 21 are connected to each other.

[0068] In practical use, the second air intake channel 21 of the inner cylinder 2 is usually selected to introduce air, and the first air intake channel 3 is selected to introduce fuel gas. Of course, the second air intake channel 21 can also be used to transport fuel gas, and correspondingly, the first air intake channel 3 can also be used to transport air. To simplify the description, the following mainly uses the second air intake channel 21 to transport air and the first air intake channel 3 to transport fuel gas as an example.

[0069] In the above basic technical solution, the gas enters the first intake channel 3 through the intake connector 5. Since the intake direction of the intake connector 5 is perpendicular to the axial direction of the first intake channel 3, and the intake connector 5 is positioned directly opposite the wall of the inner cylinder 2, this structural design causes the gas to collide with the wall of the inner cylinder 2 after entering the first intake channel 3. This causes the gas to diffuse rapidly in the circumference of the first intake channel 3. In addition, since gas molecules are inherently randomly moving, the gas can easily diffuse evenly in the first intake channel 3, resulting in a basically uniform gas output at each position when it reaches the outlet of the first intake channel 3. Because of the ceaseless and random movement of gas molecules, the macroscopic effect is disorder. Therefore, based on the uniform gas output from the first intake channel 3, it can easily mix evenly with the air from the second intake channel 21 at the outlet.

[0070] Generally, the first air intake channel 3 and the second air intake channel 21 are arranged in parallel, which makes the gas flow smoother and the gas easier to diffuse evenly.

[0071] Furthermore, the outer cylinder 1 and inner cylinder 2 can be integrally cast, and the air inlet connector 5 is also integrally set with the outer cylinder 1. This facilitates reducing the amount of materials used in the production process, lowering material management costs, and resulting in a simpler overall structure. Moreover, installation is convenient; such as... Figure 4 As shown, the air inlet of the inner cylinder 2 is connected to the port of the outer cylinder 1 to form a closed end to the outer cylinder 1. This closed end forms the first flange 8, which can be used to install the air inlet mesh plate or to connect to the air duct; of course, other connection methods can also be used, such as threaded connection.

[0072] Generally, the outer cylinder 1 and the inner cylinder 2 are preferably cylindrical, which provides better safety. Compared with square cylinders, cylindrical cylinders have no inflection points and allow for smoother gas flow. Compared with other curved cylinders (such as cylinders with elliptical cross-sections), gas can diffuse more evenly. Of course, pipes with rectangular or other shapes can also be used.

[0073] As one embodiment of air intake through the first air intake channel 3, the air intake connector 5 is perpendicular to the wall of the inner cylinder 1. For convenient connection to gas supply equipment (such as gas pipelines or gas cylinders), it can be connected using radial or axial sealing methods such as threaded connections, snap-fit ​​connections, or pin connections. Further, as... Figure 4 or Figure 10 As shown, the inner diameter of the outer end of the air inlet connector 5 is larger than the inner diameter of the inner end. The reduced inner diameter of the air inlet pipe increases the air intake speed, resulting in more intense collisions between the gas and the inner cylinder 1 and outer cylinder 2, thus facilitating more uniform diffusion within the first air intake channel 4. Furthermore, the larger outer end facilitates connection and installation with gas supply equipment. A slope or arc surface is formed between the large inner diameter end and the small inner diameter end (i.e., they are not connected at a right angle) to ensure smooth gas flow.

[0074] In order to monitor the intake pressure of the second intake channel 21 to determine whether the air pressure is abnormal, and to effectively control the input of gas and air, a pressure tapping structure can be set up to detect the pressure of air or gas, thereby adjusting the input of gas and air.

[0075] Specifically, the pressure tapping structure can be a small-hole pipe, with a section of the pipe serving as a detection channel 41. One end of the detection channel 41 passes through the outer cylinder 1 and the inner cylinder 2, and is connected to the second air intake channel 21 inside the inner cylinder 2. The other end of the detection channel 41 is connected to a pressure detection device, such as a gas pressure sensor, to detect the air pressure inside the inner cylinder 2. Alternatively, another detection channel 41 can be provided, with one end passing through the outer cylinder 1 and connected to the first air intake channel 3, to detect the gas pressure inside the outer cylinder 1.

[0076] Preferably, the detection channel 41 can extend a section of pipe to serve as a pressure tapping channel 42. The pressure tapping channel 42 is axially parallel to the inner wall of the inner cylinder 2, meaning that the pressure tapping channel 42 and the detection channel 41 are connected to form a bent structure. Even when the wind speed is low, changes in air pressure can be detected sensitively, resulting in high detection sensitivity. Furthermore, the pressure tapping port of the pressure tapping channel 42 faces the air outlet of the second air inlet channel 21, which can prevent excessive air from entering and monitor air pressure more accurately. More preferably, the pressure tapping channel 42 and the detection channel 41 form an L-shaped structure. Of course, the angle between the detection channel 41 and the pressure tapping channel 42 can be set according to the needs of the installation position to adapt to different installation environments.

[0077] During equipment operation, detection channel 41 serves as a connection port, connected to a pressure sensor. The pressure sensor monitors the air pressure through a pressure tapping structure and transmits the signal to the main controller to determine if the air pressure is abnormal. In existing technology, the pressure sensing components used in gas appliances such as gas water heaters and dual-purpose hot water / heating water heaters typically employ a pressure switch with a single activation value. When external air pressure causes blockage in the flue, causing the air pressure at the fan sampling point to exceed this activation value, the diaphragm in the pressure switch moves, thus achieving the switching purpose. However, since the pressure switch usually only has a preset activation value, it only serves a switching protection function, significantly impacting the continuity and performance of the gas appliance. This invention connects a pressure sensor to the connection port of detection channel 41, constantly monitoring the air pressure value and feeding it back to the water heater's main controller. The main controller can readjust the fan speed based on the current air pressure value, reducing the impact of flue blockage caused by external air pressure on the water heater's performance. Because the water heater's performance does not decrease, it can operate continuously without affecting user experience.

[0078] To ensure the accuracy of air pressure monitoring, the pressure tapping structure is located near the air inlet of the second air inlet channel 3, so as to monitor the air pressure at the air inlet of the second air inlet channel 21 as much as possible. The air pressure at this location is closer to the air pressure of the gas before entering the second air inlet channel 21, which allows for more intuitive and accurate monitoring of the air pressure entering the air, so as to adjust the fan speed.

[0079] More preferably, such as Figure 4 As shown, the detection channel 41 is the first flange 8 that passes through the air inlet of the outer cylinder 1 and the air inlet of the inner cylinder 2. Compared with directly passing through the outer cylinder 1 and the inner cylinder 2, it is easier to ensure the sealing between the detection channel 41 and the outer cylinder 1 and the inner cylinder 2.

[0080] By setting up the aforementioned pressure tapping structure, the pressure of air or fuel gas can be easily detected, thereby adjusting the input of air or fuel gas and controlling the air and fuel gas mixture within a certain mixing ratio range, reducing the content of harmful gases in combustion exhaust emissions. Furthermore, since the pressure tapping channel 42 is fixed in position, the pressure tapping data has good consistency, avoiding data deviations caused by assembly differences. Moreover, the pressure tapping structure can be integrally formed on the inner cylinder 1 and outer cylinder 2, making the inner cylinder 1, outer cylinder 2, and pressure tapping structure a unified whole. This structure is stable, provides accurate pressure tapping, and eliminates the need for assembly, reducing assembly defects and improving installation efficiency.

[0081] In addition, to better protect the equipment, an air inlet mesh plate can be installed at the air inlet of the inner cylinder 2. Specifically, an air inlet mesh plate is installed on the first flange 8 at the air inlet of the inner cylinder 2 to prevent foreign objects from entering the equipment and reduce the failure rate.

[0082] Based on the aforementioned premixing device, it is adapted to general fans; for example, referring to Figures 9 to 14 As shown, a second flange 9 can be installed on the outer cylinder 1 near the air outlet, along the circumference of the outer cylinder 1. The premixing device is then installed on the blower via the second flange 9. Specifically, the air outlet of the outer cylinder 1 is connected to the air inlet of the blower. A sealing gasket is installed between the second flange 9 and the blower to ensure a tight seal. Alternatively, the premixing device can also be applied to other equipment requiring gas mixing via the second flange 9. For example, ... Figures 4 to 8 As shown, the premixing device is connected to the cover plate 6 to form a fan cover plate, and the air outlet of the outer cylinder 1 is sealed to the through hole on the cover plate 6; furthermore, the premixing device and the cover plate 6 are integrally set, that is, the outer cylinder 1, the inner cylinder 2, the pressure tapping structure and the cover plate 6 are cast as one piece, which further reduces the amount of materials in the production process and reduces material management costs.

[0083] To facilitate understanding of the premixing device of the present invention, the following further describes a fan assembly incorporating the above-described premixing device, which can relatively specifically describe the structural form of the premixing device of the present invention adapted to a general fan.

[0084] like Figure 15 and Figure 16 As shown, the premixing device of the present invention is mounted on the fan assembly via a cover plate 6, referring to... Figure 3 As shown, the air outlet of the outer cylinder 1 of the premixing device passes through the through hole on the cover plate 6, and the outer cylinder 1 is sealed to the cover plate 6.

[0085] Specifically, to effectively prevent gas leakage, the outer wall of the outer cylinder 1 is connected to the cover plate 6 as a single unit. Overall, the outer cylinder 1, inner cylinder 2, pressure tapping structure, and cover plate 6 are integrally formed. This structural design, without connecting gaps, effectively prevents gas leakage and improves equipment safety. Furthermore, integrating them into a single component reduces the number of materials, lowers material management costs, and improves installation efficiency. Of course, simple modifications can be made, such as threaded connection between the outer cylinder 1 and cover plate 6, with an annular protrusion extending from the outer circumference of the outer cylinder 1 to compress the sealing gasket between the outer cylinder 1 and cover plate 6 to achieve a seal; or welding the connection between the outer wall of the outer cylinder 1 and the through hole of the cover plate 6 to achieve a seal, etc.

[0086] Generally, the cover plate 6 is connected to the volute housing 71. Figure 15 An example of a flange connection between the cover plate 6 and the volute housing 71 is shown. Of course, the cover plate 6 and the volute housing 71 can also be connected by radial or axial sealing methods such as snap-fit ​​connection or pin connection. A cavity is formed between the cover plate 6 and the volute housing 71, and the outer cylinder 1 and the inner cylinder 2 communicate with the cavity. A fan 72 is installed on the volute housing 71, and an air outlet is also provided on the volute housing 71.

[0087] Reference Figure 4 or Figure 10 As shown, the wall of the outlet of the outer cylinder 1 extends beyond the wall of the outlet of the inner cylinder 2, allowing the air and fuel gas to mix once at the front of the fan. Then, under its own pressure and the suction force of the fan, the fuel gas enters the first intake channel 3 from the intake structure. At the junction of the two, it collides with the wall of the inner cylinder 2 and diffuses to the periphery of the first intake channel 3, flowing towards the outlet. At the outlet, it merges with the air that has been drawn in and is drawn into the fan assembly, completing the secondary mixing process of air and fuel gas. This allows for a more thorough mixing of air and fuel gas, reducing the content of harmful gases in the exhaust emissions.

[0088] like Figures 4 to 16As shown, the fan assembly of the preferred embodiment of the present invention includes a premixing device, a cover plate 6, a volute housing 71, and a fan 72 mounted on the volute housing 71. The premixing device includes an outer cylinder 1, an inner cylinder 2, and a pressure tapping structure. The outer cylinder 1 is sleeved outside the inner cylinder 2, and the edge of the air inlet of the inner cylinder 2 is connected to the edge of the air inlet of the outer cylinder 1, thus sealing that end of the outer cylinder 1. This sealing structure forms a first flange 8. Through this structural design, the gas can only flow to the outlet, preventing gas leakage. An air inlet mesh plate is installed on the first flange 8 to prevent foreign objects from entering the inner cylinder 2, reducing the failure rate. The detection channel 41 of the pressure tapping structure penetrates the first flange 8 and extends a pressure tapping channel 42 inside the inner cylinder 2. The pressure tapping channel 42 is parallel to the inner wall of the inner cylinder 2 along the axial direction. The detection channel 41 and the pressure tapping channel 42 form an L-shaped structure. The port of the pressure tapping channel 42 faces the air outlet of the inner cylinder 2, which has high sensitivity for detecting air pressure. The inner cylinder 2 and the outer cylinder 1 form a first air inlet channel 3 at an interval, and the outer cylinder 1 is provided with an air inlet connector 5, which is connected to the first air inlet channel 3. The air outlet of the outer cylinder 1 is connected to the cover plate 6 and communicates with the cavity formed between the cover plate 6 and the volute housing 71. The cover plate 6 and the volute housing 71 are connected by a flange seal. Among them, the outer cylinder 1, the inner cylinder 2, the pressure tapping structure and the cover plate 6 are cast as one piece, which reduces the number of materials, reduces material management costs and improves installation efficiency.

[0089] Based on the above-mentioned technical solution for the fan assembly, it can be adapted to the structure of a general gas water heater.

[0090] The gas inlet connector 5 can be connected to an external gas pipeline, the gas inlet of the inner cylinder 2 is connected to an external air pipeline, the detection channel 41 of the pressure tapping structure is connected to an external pressure detection device, such as a gas pressure sensor, and the gas outlet of the volute housing 71 is connected to the burner of the gas water heater. During operation, the fan 72 starts, and the gas enters the first air inlet channel 3 from the air inlet structure under its own pressure and the suction force of the fan 72. At the junction of the two, it collides with the outer wall of the inner cylinder 2 and diffuses to various parts of the first air inlet channel 3, and flows towards the gas outlet. At the gas outlet, it merges with the air drawn in from the air inlet of the second air inlet channel 21 of the inner cylinder 2. The gas is first mixed at the gas outlet of the outer cylinder 1 and the inner cylinder 2, and then it is drawn into the fan assembly. The air and gas are mixed again in the cavity formed between the cover plate 6 and the volute housing 71. Then, it enters the burner of the gas water heater from the gas outlet of the volute housing 71 to achieve combustion. During equipment operation, the detection channel port of the pressure tapping structure is connected to a pressure sensor. The pressure sensor monitors the air pressure inside the inner cylinder 2 through the pressure tapping structure and transmits the signal to the main controller to determine if the air pressure is abnormal. This allows for adjustment of the air or fuel gas input, ensuring thorough mixing and combustion of air and fuel gas, and reducing the content of harmful gases in exhaust emissions. The main controller is an existing controller, such as a PLC or microcontroller.

[0091] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A premixing device, comprising an outer cylinder (1) and an inner cylinder (2), characterized in that, The outer cylinder (1) is fitted onto the inner cylinder (2) to form an integral double-layer cylindrical structure, and the spacer between the two forms a first air intake channel (3). An air intake connector (5) is integrally connected to the outer cylinder (1). The air intake direction of the air intake connector (5) is perpendicular to the axial direction of the first air intake channel (3), and the air intake connector (5) is set facing the cylinder wall of the inner cylinder (2). The cylinder cavity of the inner cylinder (2) forms a second air intake channel (21). The air outlets of the first air intake channel (3) and the second air intake channel (21) are connected to each other. The premixing device also includes a pressure tapping structure for detecting the pressure inside the inner cylinder (2). The pressure tapping structure includes a detection channel (41), which passes through the outer cylinder (1) and the inner cylinder (2) and is connected to the second air inlet channel (21). The outer cylinder (1), the inner cylinder (2) and the pressure tapping structure are cast as a single piece. The pressure tapping structure further includes a pressure tapping channel (42), which is located inside the inner cylinder (2) and parallel to the cylinder wall of the inner cylinder (2). The detection channel (41) is connected to the pressure tapping channel (42) to form a bent structure. The pressure tapping structure is located near the air inlet of the second air inlet channel (21); The detection channel (41) is a first flange (8) that passes through the air inlet of the outer cylinder (1) and the air inlet of the inner cylinder (2). The bottom wall of the first flange (8) seals the cylinder wall of the inner cylinder (2) and the cylinder wall of the outer cylinder (1) to form the first air inlet channel (3). The pressure tapping channel (42) is formed between the inner wall of the first flange (8) and the inner wall of the inner cylinder (2). The first air intake channel (3) is arranged in parallel with the second air intake channel (21); The wall of the air outlet of the outer cylinder (1) extends beyond the wall of the air outlet of the inner cylinder (2).

2. The premixing device according to claim 1, characterized in that, An air inlet mesh plate is installed on the first flange (8).

3. The premixing device according to claim 2, characterized in that, The outer cylinder (1) has a second flange (9) circumferentially arranged at the air outlet end.

4. A fan cover plate, characterized in that, Includes a premixing device and a cover plate (6) according to any one of claims 1 to 3, wherein the air outlet of the outer cylinder (1) is sealed to the through hole on the cover plate (6).

5. The fan cover plate according to claim 4, characterized in that, The premixing device and the cover plate (6) are cast as a single unit.

6. A fan assembly, characterized in that, Including the fan cover and fan assembly according to claim 4 or 5, the premixing device is mounted on the fan assembly via the cover (6).

7. The wind turbine assembly according to claim 6, characterized in that, The fan assembly includes a volute housing (71) and a fan (72) mounted on the volute housing (71). The cover plate (6) is connected to the volute housing (71) to form a cavity. The second air intake channel (21) and the first air intake channel (3) are respectively connected to the cavity.

8. A gas water heater, characterized in that, Includes the wind turbine assembly according to any one of claims 6 or 7.

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