Smoke exhaust device and gas furnace

Abstract

The invention discloses a smoke exhaust device and a gas stove, the smoke exhaust device is used for the gas stove, the smoke exhaust device comprises a fan assembly and a volute assembly, the fan assembly comprises a motor and an impeller, the impeller comprises a plurality of arc-shaped blades, the blades are arranged at intervals in the circumferential direction of the impeller, and the motor is used for driving the impeller to rotate so as to form airflow flowing in the preset direction; the volute assembly forms a containing cavity, an air inlet and an air outlet, the air inlet and the air outlet are communicated with the containing cavity, the impeller is contained in the containing cavity, the rotating center of the impeller is located at the air inlet, and the air outlet is located on one side of the volute assembly in the radial direction of the impeller. Wherein the ratio of the chord length L of the blades to the radius R of the impeller meets the condition that L / R is larger than or equal to 0.49 and smaller than or equal to 0.56; the ratio of the inlet diameter D1 of the impeller to the outlet diameter D2 of the impeller meets the condition that D1 / D2 is larger than or equal to 0.48 and smaller than or equal to 0.62. The ratio of the axial width H of the impeller to the outlet diameter D2 of the impeller meets the condition that H / D2 is larger than or equal to 0.16 and smaller than or equal to 0.26.

Description

Technical Field

[0001] This application relates to the field of household appliance technology, and in particular to a smoke extraction device and a gas stove. Background Technology

[0002] A gas-fired boiler is a heating product that generates high-temperature flue gas by burning natural gas or liquefied petroleum gas, and then uses this flue gas to exchange heat with cold air to heat indoor air. Gas-fired boilers are equipped with exhaust fans that introduce fresh air and exhaust combustion waste gases such as carbon dioxide and water vapor. However, when combined with long flue pipes or strong external convective air interference, resulting in high external static pressure, insufficient airflow or pressure from the exhaust fan can easily trigger the protection mechanism and cause it to stop operating. Therefore, improving the performance of the exhaust fan has become a technical problem that needs to be solved. Summary of the Invention

[0003] This application provides a flue gas exhaust device and a gas furnace, which at least improves the pressure resistance of the flue gas exhaust device.

[0004] This application provides a flue gas exhaust device for a gas furnace. The flue gas exhaust device includes a fan assembly and a volute assembly. The fan assembly includes a motor and an impeller. The impeller includes multiple arc-shaped blades, which are arranged at intervals along the circumference of the impeller. The motor drives the impeller to rotate to form an airflow flowing in a preset direction. The volute assembly has a receiving cavity and an air inlet and an air outlet communicating with the receiving cavity. The impeller is received in the receiving cavity. The rotation center of the impeller is located at the air inlet, and the air outlet is located on one side of the volute assembly along the radial direction of the impeller.

[0005] The ratio of the blade chord length L to the impeller radius R conforms to the following condition: 0.49 ≤ L / R ≤ 0.56.

[0006] The ratio of the impeller inlet diameter D1 to the impeller outlet diameter D2 conforms to the following condition: 0.48≤D1 / D2≤0.62;

[0007] The ratio of the impeller's axial width H to the impeller's outlet diameter D2 conforms to the following condition: 0.16 ≤ H / D2 ≤ 0.26.

[0008] In the smoke exhaust device of this application embodiment, the blades are designed with a large chord length structure, and the ratio of the inlet and outlet diameters and axial width of the impeller is optimized, thereby improving the smoke exhaust device's adaptability to external static pressure, increasing static pressure, and thus improving the high pressure resistance performance of the smoke exhaust fan to adapt to more complex working conditions.

[0009] In some implementations, the exit angle of the blade is an obtuse angle.

[0010] Thus, the blade outlet angle is obtuse, and the impeller is a forward centrifugal impeller. Compared with the backward impeller used in most centrifugal fans, the impeller speed and physical size are smaller under the same flow rate and total pressure, which helps to reduce noise.

[0011] In some embodiments, the exit angle of the blade ranges from 159°±9°, and / or the inlet angle of the blade ranges from 90°±5°.

[0012] In this way, by setting the outlet angle and / or inlet angle of the blades within a reasonable range, the airflow can be smoothly introduced into and discharged from the impeller, reducing resistance loss, increasing air volume, increasing static pressure, and further reducing noise.

[0013] In some embodiments, the impeller includes a chassis and a frame coaxial with the impeller. The chassis is located on one side of the impeller axis and covers the blades. The ends of the blades away from the air inlet extend out of the chassis. The frame is located on the side of the impeller axis opposite to the chassis and covers the ends of the blades away from the air inlet.

[0014] The ratio of the outer diameter D4 of the chassis to the outlet diameter D2 of the impeller conforms to the following condition: 0.48≤D4 / D2≤0.62.

[0015] Thus, by designing a reasonable ratio between the outer diameter D4 of the chassis and the outlet diameter D2 of the impeller, the strength of the impeller frame and the structural strength of the chassis, as well as the impact on noise, are balanced, achieving a comprehensive effect of better structural strength and lower noise.

[0016] In some implementations, the inner diameter D6 of the frame and the outer diameter D4 of the chassis are related as follows:

[0017] D6≥D4;

[0018] The outer diameter D5 of the frame and the outlet diameter D2 of the impeller have the following relationship:

[0019] 0.98*D2<D5<1.02*D2.

[0020] Thus, the inner diameter D6 of the design frame is greater than or equal to the outer diameter D4 of the chassis, which facilitates mold design, enables one-time demolding, and improves the production efficiency of impeller products. The ratio of the outer diameter D5 of the design frame to the outlet diameter D2 is close to 1:1, resulting in a smaller draft angle and thus reducing the difference between the mold part and the design part.

[0021] In some embodiments, the impeller also includes a fastener that passes through the center of the chassis along the axial direction of the impeller. The chassis includes a protective element that covers the end of the fastener facing the frame.

[0022] In this way, by covering the ends of the fasteners facing the frame with protective parts, the acidic condensate produced after combustion in the gas furnace is prevented from corroding the motor shaft and fasteners.

[0023] In some embodiments, the volute assembly includes a volute body, the volute body includes a curved portion and an outlet portion connecting the curved portion, the curved portion covers the impeller, the outlet portion forms an air outlet, the upper edge of the outlet portion is connected to the top of the curved portion, and the ratio of the vertical distance H1 from the lower edge of the outlet portion to the center of rotation of the impeller to the height H2 of the volute body is: 0.23≤H1 / H2≤0.3.

[0024] In this way, by setting the ratio of H1 from the lower edge of the outlet to the impeller rotation center to the height H2 of the volute body within a reasonable range, the fit between the volute curve and the impeller is improved, which is conducive to the uniform discharge of airflow along the circumference of the impeller and into the receiving cavity, thus achieving a stable and uniform flow effect.

[0025] In some embodiments, the ratio of the opening A of the volute body to the height H2 of the volute body conforms to the following condition: 0.125≤A / H2≤0.145, and the spiral initiation angle θ of the volute body is in the range of 59°<θ<63°.

[0026] Thus, by setting the ratio of the opening degree A of the volute body to the height H2 of the volute body and the spiral starting angle θ of the volute body within a preset range, a volute profile adapted to the impeller is formed, so that the gas is evenly discharged into the receiving cavity along the circumference of the impeller, achieving a stable and uniform flow effect and improving the low-noise and high-efficiency performance of the smoke exhaust device.

[0027] In some embodiments, the volute assembly includes a volute body, on which a pressure tapping structure communicating with the receiving cavity is provided. The pressure tapping structure includes a first end near the air inlet and a second end away from the air inlet, with the first end located near the air inlet.

[0028] Thus, by setting a pressure tapping structure connected to the receiving cavity, pressure is taken from the first end to detect the real-time air pressure, thereby facilitating the control of the motor speed through real-time air pressure.

[0029] In some embodiments, the ratio of the distance R3 between the first end and the impeller rotation center to the impeller outlet diameter D2 is: 0.35≤R3 / D2≤0.39, and the line connecting the first end and the impeller rotation center forms an angle β with the line connecting the first end and the volute tongue of the volute body, the angle β being in the range of: 50°<β<60°.

[0030] In this way, by setting the first end at a reasonable position on the impeller circumference, the position of the airflow is avoided, ensuring that the pressure fluctuation at the pressure tap is small, and the obtained air pressure is not likely to exceed the negative pressure range when the external static pressure fluctuates greatly.

[0031] Secondly, this application provides a gas furnace, which includes a flue gas exhaust device and a burner according to any of the above embodiments. The burner is used to provide a carrier for fuel combustion, and the flue gas exhaust device is used to discharge combustion exhaust gas.

[0032] The gas furnace according to the embodiments of this application, because it includes the exhaust device of any of the above embodiments, has all the beneficial effects of the exhaust device according to the embodiments of this application.

[0033] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0034] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0035] Figure 1 This is a schematic diagram of the structure of a gas furnace according to certain embodiments of this application;

[0036] Figure 2 This is a schematic diagram of the smoke exhaust device according to some embodiments of this application;

[0037] Figure 3 This is a cross-sectional structural schematic diagram of a smoke exhaust device according to certain embodiments of this application;

[0038] Figure 4 This is an exploded structural diagram of a smoke exhaust device according to certain embodiments of this application;

[0039] Figure 5 This is a schematic diagram of the movement trajectory of the blades in some embodiments of this application;

[0040] Figure 6 This is a schematic diagram of the impeller structure in some embodiments of this application;

[0041] Figure 7 This is a structural schematic diagram of the impeller of some embodiments of this application from a rear-view perspective;

[0042] Figure 8 This is a structural schematic diagram of the impeller of some embodiments of this application from a left-hand view.

[0043] Figure 9 This is a structural schematic diagram of the impeller of some embodiments of this application from a front-view perspective;

[0044] Figure 10 This is a cross-sectional structural diagram of a smoke exhaust device according to certain embodiments of this application, excluding the motor.

[0045] Figure 11 This is a schematic diagram of the structure of the volute body according to certain embodiments of this application;

[0046] Figure 12 This is a schematic diagram showing the position of the impeller within the volute body in some embodiments of this application;

[0047] Figure 13 This is a structural schematic diagram of the volute body of some embodiments of this application from a rear-view perspective;

[0048] Figure 14 This is a structural schematic diagram of the end cap of some embodiments of this application from a frontal view.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1000-Gas furnace; 100-Exhaust device; 10-Fan assembly; 11-Motor; 112-Drive shaft; 12-Impeller; 121-Blade; 122-Chassis; 123-Frame; 124-Fasteners; 125-Protective components; 20-Volume assembly; 201-Receiving cavity; 202-Air inlet; 203-Air outlet; 21-Bracket; 22-Volume body; 221-Curved section; 223-Outlet section; 222-Main body section; 225-Base plate; 226-Enclosure plate; 227-End cover; 30-Pressure tapping structure; 31-First end; 311-Through hole; 32-Second end; 40-Fume pipe; 200-Burner. Detailed Implementation

[0051] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0052] In the description of the embodiments of this application, 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," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the embodiments of this application and simplifying the description, 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, and therefore should not be construed as a limitation on the embodiments of this application. 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 indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0053] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" 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 mechanical connection, an electrical connection, or a connection that allows for communication; 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 the embodiments of this application according to the specific circumstances.

[0054] In embodiments of this application, unless otherwise expressly 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 being 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 being 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.

[0055] The following disclosure provides numerous different embodiments or examples for implementing various structures of the embodiments of this application. To simplify the disclosure of the embodiments of this application, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Reference numerals and / or reference letters may be repeated in different examples of the embodiments of this application; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Furthermore, the embodiments of this application provide examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0056] Please see Figures 1-5 This application provides a flue gas exhaust device 100 for a gas furnace 1000. The flue gas exhaust device 100 includes a fan assembly 10 and a volute assembly 20. The fan assembly 10 includes a motor 11 and an impeller 12. The impeller 12 includes a plurality of arc-shaped blades 121, which are arranged at intervals along the circumference of the impeller 12. The motor 11 is used to drive the impeller 12 to rotate to form an airflow flowing in a preset direction. The volute assembly 20 forms a receiving cavity 201 and an air inlet 202 and an air outlet 203 communicating with the receiving cavity 201. The impeller 12 is received in the receiving cavity 201. The rotation center O1 of the impeller 12 is located at the air inlet 202, and the air outlet 203 is located on one side of the volute assembly 20 along the radial direction of the impeller 12.

[0057] The ratio of the chord length L of blade 121 to the radius R of impeller 12 is: 0.49≤L / R≤0.56;

[0058] The ratio of the inlet diameter D1 to the outlet diameter D2 of impeller 12 conforms to the following condition: 0.48≤D1 / D2≤0.62;

[0059] The ratio of the axial width H of impeller 12 to the outlet diameter D2 of impeller 12 is: 0.16≤H / D2≤0.26.

[0060] In the smoke exhaust device 100 of this application embodiment, the blades 121 are designed with a large chord length structure, and the ratio of the inlet and outlet diameters and axial width of the impeller 12 is optimized, thereby improving the adaptability of the smoke exhaust device 100 to external static pressure, increasing static pressure, and thus improving the high pressure resistance performance of the smoke exhaust fan, adapting to more complex working conditions.

[0061] Specifically, the smoke exhaust device 100 is generally volute-shaped, and the inner wall of the volute assembly 20 forms a receiving cavity 201. The motor 11 can be mounted on the volute assembly 20 and located on the side opposite to the air inlet 202. The motor 11 includes a drive shaft 112, which connects to the impeller 12 and forms the rotation center O1 of the impeller 12. The drive shaft 112 passes through the wall of the volute assembly 20 along the axial direction of the impeller 12 toward the air inlet 202, so that the end of the drive shaft 112 extends into the volute assembly 20.

[0062] Optionally, the volute assembly 20 also includes a bracket 21, which is fixedly connected to the motor 11 to stably mount the motor 11 on the volute assembly 20.

[0063] Along the circumference of the impeller 12, the surface of the blade 121 protrudes into an arc-shaped curved surface, and the direction of rotation of the impeller 12 is opposite to the direction of the arc-shaped protrusion of the blade 121. The arc-shaped curved surfaces of two adjacent blades 121 are opposite to each other and spaced apart along the circumference of the impeller 12, and the shape and size of the interval between each two adjacent blades 121 are the same.

[0064] With the impeller 12 in a horizontal position, Figure 5 The image shows a projection of a blade 121 along a horizontal direction, with the projection plane being a vertical plane perpendicular to the axis of the impeller 12. The profile shape of the blade 121 can be as follows: Figure 5 The dot shown is part of the circle O1. The chord length L of blade 121 is the straight-line distance between the tip A and the tail B of blade 121. Along the radial direction of impeller 12, the tip A of blade 121 is located in the inner periphery of impeller 12, and the tail B of blade 121 is located in the outer periphery of impeller 12. The tip A of blade 121 is closer to the rotation center O1 of impeller 12 than the tail B.

[0065] When the motor 11 drives the impeller 12 to rotate, a negative pressure is formed at the air inlet 202. The airflow enters the receiving cavity 201 from the air inlet 202 along the axial direction of the impeller 12, and is discharged from the air outlet 203 along the radial direction of the impeller 12. The tip A and tail B of the blades 121 respectively form... Figure 5 The motion trajectories shown are I and II. Both motion trajectories I and II are circular and concentric, with their centers both being the rotation center O1 of impeller 12. It is easy to understand that the diameter of motion trajectory I is the inlet diameter D1 of impeller 12, and the diameter of motion trajectory II is the outlet diameter D2 of impeller 12; the radius of motion trajectory II is the radius R of impeller 12, which is also the distance between the rotation center O1 of impeller 12 and its tail end B.

[0066] For example, the ratio of the chord length L of the blade 121 to the radius R of the impeller 12 can be 0.49, 0.5, 0.52, 0.55, or 0.56. Similarly, the value of D1 / D2 can be 0.48, 0.5, 0.56, 0.57, 0.6, or 0.62. And the value of H / D2 can be 0.16, 0.18, 0.21, 0.225, or 0.26. In a preferred embodiment, the ratios of the chord length L of the blade 121 to the radius R of the impeller 12, the inlet diameter D1 of the impeller 12 to the outlet diameter D2 of the impeller 12, and the axial width H of the impeller 12 to the outlet diameter D2 of the impeller 12 can be L / R = 0.53, D1 / D2 = 0.545, and H / D2 = 0.22, respectively.

[0067] Optionally, the number of blades 121 ranges from 51 to 67, for example, the number of blades 121 can be 51, 53, 56, 65, or 67. In a preferred embodiment, the number of blades 121 is 61.

[0068] Please see Figure 5 and Figure 6 In some embodiments, the exit angle α1 of the blade 121 is an obtuse angle.

[0069] Thus, the outlet angle α1 of the blade 121 is an obtuse angle, and the impeller 12 is a forward centrifugal impeller 12. Therefore, compared with the backward impeller 12 used in most centrifugal fans, the impeller 12 has a smaller rotational speed and physical size under the same flow rate and total pressure, which is beneficial to reducing noise.

[0070] Specifically, such as Figure 5 As shown, the exit angle α1 of blade 121 is the angle between the outer extension of blade 121 at tail end B and the opposite direction of the tangent to the rotation direction of tail end B. The exit angle α1 is an obtuse angle, that is, the angle between the outer extension of blade 121 at tail end B and the opposite direction of the tangent to the rotation direction is greater than 90°.

[0071] Please see Figure 5 In some embodiments, the exit angle α1 of the blade 121 ranges from 159°±9°, and / or the inlet angle α2 of the blade 121 ranges from 90°±5°.

[0072] Thus, by setting the outlet angle α1 and / or inlet angle α2 of the blade 121 within a reasonable range, the airflow can be smoothly introduced into and discharged from the impeller 12, thereby reducing resistance loss, increasing air volume, increasing static pressure, and further reducing noise.

[0073] Specifically, in combination Figure 4The inlet angle α2 is the angle between the gas and the normal to the surface of the impeller 12 when the gas enters the impeller 12 in the exhaust device 100. In a preferred embodiment, the outlet angle α1 and the inlet angle α2 of the blade 121 are designed to be α1 = 159° and α2 = 90°, respectively.

[0074] Please see Figures 6-9 In some embodiments, the impeller 12 includes a chassis 122 and a frame 123 coaxial with the impeller 12. The chassis 122 is located on one side of the impeller 12 axis and covers the blades 121. The end of the blades 121 away from the air inlet 202 extends out of the chassis 122. The frame 123 is located on the side of the impeller 12 axis opposite to the chassis 122, and the frame 123 covers the end of the blades 121 away from the air inlet 202.

[0075] The ratio of the outer diameter D4 of the chassis 122 to the outlet diameter D2 of the impeller 12 is: 0.48≤D4 / D2≤0.62.

[0076] Thus, by designing a reasonable ratio between the outer diameter D4 of the chassis 122 and the outlet diameter D2 of the impeller 12, the strength of the impeller 12 frame 123 and the structural strength of the chassis 122, as well as the impact on noise, are balanced, achieving a comprehensive effect of better structural strength and lower noise.

[0077] Specifically, the chassis 122 and the frame 123 are both annular, the blades 121 are all fixedly connected to the chassis 122, and multiple blades 121 are evenly spaced and arranged circumferentially on the chassis 122. A through hole is formed in the center of the chassis 122 for installing a bushing.

[0078] The frame 123 is a thin ring, covering only a portion of the end face of the blade 121. The frame 123 strengthens the structural integrity of the blade 121 and simultaneously prevents the airflow from the outlet 203 from flowing back to the inlet 202. The inner and outer diameters of the frame 123 are close to the outlet diameter D2 of the blade 121. The end of the blade 121 furthest from the outlet 203 extends beyond the chassis 122; that is, the outlet diameter D2 of the blade 121 is greater than the outer diameter D4 of the chassis 122, where D2 > D4.

[0079] It should be noted that as the outer diameter of the chassis 122 decreases, the noise will increase, while as the inner diameter of the frame 123 increases, the strength of the frame 123 will decrease. Therefore, it is necessary to rationally design the ratio between the outer diameter D5 and inner diameter D6 of the frame 123, the outer diameter of the chassis 122, and the outlet diameter of the blade 121 to balance the overall effect of structural strength and noise.

[0080] In a preferred embodiment, D4 / D2 = 0.545.

[0081] Please see Figures 6-9In some embodiments, the inner diameter D6 of the frame 123 and the outer diameter D4 of the chassis 122 have the following relationship:

[0082] D6≥D4;

[0083] The outer diameter D5 of frame 123 and the outlet diameter D2 of impeller 12 have the following relationship:

[0084] 0.98*D2<D5<1.02*D2.

[0085] Thus, the inner diameter D6 of the frame 123 is greater than or equal to the outer diameter D4 of the chassis 122, which facilitates mold design, enables one-time demolding, and improves the production efficiency of the impeller 12. The ratio of the outer diameter D5 of the frame 123 to the outlet diameter D2 is close to 1:1, resulting in a smaller draft angle and thus reducing the difference between the mold part and the designed part.

[0086] Specifically, the outer diameter D5 of the frame 123 is slightly larger than the inner diameter D6 of the frame 123, so there is a relationship: D5>D6≥D4.

[0087] In a preferred embodiment, the outer diameter D5 of the frame 123 is equal to the outlet diameter D2 of the impeller 12, that is, D5 = D2. In this embodiment, D2 = D5 > D6 ≥ D4.

[0088] Please see Figure 10 In some embodiments, the impeller 12 further includes a fastener 124, which passes through the center of the chassis 122 along the axial direction of the impeller 12. The chassis 122 includes a protective member 125 that covers the end of the fastener 124 facing the frame 123.

[0089] Thus, by covering the end of the fastener 124 facing the frame 123 with the protective element 125, the acidic condensate generated after combustion in the gas furnace 1000 is prevented from corroding the motor 11 shaft and the fastener 124.

[0090] Specifically, fastener 124 can be a fastening nut, which passes through a hole in the center of chassis 122. Protective component 125 can be made of a material with good covering properties and corrosion resistance, such as plastic.

[0091] Please see Figures 10-12 In some embodiments, the volute assembly 20 includes a volute body 22, which includes a curved portion 221 and an outlet portion 223 connecting the curved portion 221. The curved portion 221 covers the impeller 12, and the outlet portion 223 forms an air outlet 203. The upper edge of the outlet portion 223 is connected to the top of the curved portion 221. The ratio of the vertical distance H1 from the lower edge of the outlet portion 223 to the rotation center O1 of the impeller 12 to the height H2 of the volute body 22 is: 0.23≤H1 / H2≤0.3.

[0092] Thus, by setting the ratio of H1 from the lower edge of the outlet 223 to the rotation center O1 of the impeller 12 to the height H2 of the volute body 22 within a reasonable range, the fit between the volute curve and the impeller 12 is improved, which is conducive to the uniform discharge of airflow along the circumference of the impeller 12 and into the receiving cavity 201, thereby achieving a stable and uniform flow effect.

[0093] Specifically, when the exhaust device 100 is placed vertically, the impeller 12 remains horizontal along its axis, and the direction from the upper edge of the outlet 223 to the lower edge (as shown in the figure, the vertical direction) is vertical. The height of the impeller 12 and the volute assembly 20 is measured along the vertical direction. In a preferred embodiment, H1 / H2 = 0.27.

[0094] Combination Figure 2 and Figure 3 The outer contour of the curved section 221 is spiral-shaped, and the outlet section 223 is approximately cylindrical. Both the curved section 221 and the outlet section 223 are hollow structures and interconnected. The curved section 221 forms a receiving cavity 201 and an air inlet 202. The impeller 12 is housed within the curved section 221. An air inlet 202 is formed on one side of the curved section 221 along the axial direction of the impeller 12, and a motor 11 is provided on the other side. The drive shaft 112 of the motor 11 passes through one side wall of the curved section 221 and extends into the receiving cavity 201.

[0095] It should be noted that the curved portion 221 and the main body portion 222 are two parts with different outlines of the volute body 22, and should not be considered as two separate parts. The curved portion 221 and the main body portion 222 can be connected as one piece, or they can be assembled from several separate parts. For example, the volute body 22 includes a separate main body portion 222 and an end cap 227. The main body portion 222 forms an opening on one side along the axial direction of the impeller 12, and the end cap 227 covers the opening of the main body portion 222. The main body portion 222 includes a base plate 225 opposite to the end cap 227 along the axial direction of the impeller 12 and a surrounding plate 226 connecting the end cap 227 and surrounding the impeller 12 circumferentially. Parts of the outlines of the main body portion 222 and the end cap 227 are helical, and the helical part of the main body portion 222 and the end cap 227 together form the curved portion 221.

[0096] Please see Figure 12 In some embodiments, the ratio of the opening degree A of the volute body 22 to the height H2 of the volute body 22 is: 0.125≤A / H2≤0.145, and the spiral initiation angle θ of the volute body 22 is in the range of 59°<θ<63°.

[0097] Thus, by setting the ratio of the opening degree A of the volute body 22 to the height H2 of the volute body 22 and the spiral starting angle θ of the volute body 22 within a preset range, a volute profile adapted to the impeller 12 is formed, so that the gas is evenly discharged into the receiving cavity 201 along the circumference of the impeller 12, achieving a stable and uniform flow effect and improving the low-noise and high-efficiency performance of the smoke exhaust device 100.

[0098] Specifically, when the smoke exhaust device 100 is placed vertically, the axial direction of the impeller 12 remains horizontal. As shown in the figure, the vertical direction is the up and down direction. The spiral center of the volute body 22 and the rotation center O1 of the impeller 12 overlap along the projection in the horizontal direction. The spiral starting angle θ is the angle between the starting section of the volute profile and the up and down direction.

[0099] The opening A is the width of the final section, where the final section of the volute profile is the outlet section of the gas leaving the impeller 12. For example... Figure 12 As shown, the opening A can also be taken as the cross-sectional width at the junction of the spiral line of the curved part 221 and the outlet part 223.

[0100] In a preferred embodiment, A / H2 = 0.136 and θ = 61°. The volute body 22 guides the gas leaving the impeller 12 to the outlet 203 and converts part of the gas's kinetic energy into static pressure. By optimizing the opening A of the final section and the design of the initial section, the flow loss of the gas can be reduced, and the aerodynamic performance of the impeller 12 can be improved.

[0101] Please see Figure 10 and Figure 13 In some embodiments, the volute assembly 20 includes a volute body 22, on which a pressure-taking structure 30 communicating with the receiving cavity 201 is provided. The pressure-taking structure 30 includes a first end 31 near the air inlet 202 and a second end 32 away from the air inlet 202. The first end 31 is located near the air inlet 202.

[0102] Thus, by setting a pressure-taking structure 30 that communicates with the receiving cavity 201, pressure is taken from the first end 31 to detect the real-time air pressure, thereby facilitating the control of the motor 11 speed through the real-time air pressure.

[0103] Specifically, the pressure tapping structure 30 can be a hollow tube, with its first end 31 connected to one side of the volute body 22 and communicating with the receiving cavity 201, and its second end 32 extending outside the volute body 22. The pressure tapping structure 30 is connected to a negative pressure detection device (not shown) through its second end 32 to provide feedback on the real-time air pressure in the receiving cavity 201. The motor 11 can adjust its speed based on the real-time air pressure obtained from the pressure tapping structure 30 to ensure stable airflow, thereby enabling the motor 11 to adapt to external static pressure.

[0104] Optionally, in one example, the volute body 22 includes a base plate 225, an end cap 227, and a surrounding plate 226. The base plate 225 and the end cap 227 are opposite each other along the axial direction of the impeller 12. The surrounding plate 226 connects the base plate 225 and the end cap 227 and surrounds the impeller 12 circumferentially. An air inlet 202 is formed at the center of the end cap 227, and a perforation is formed at the center of the base plate 225. The drive shaft 112 of the motor 11 passes through the perforation and extends into the volute body 22 and is connected to the impeller 12. A pressure-taking structure 30 is provided on the end cap 227, and a through hole 311 is formed at the first end 31 and extends through the end cap 227 along the thickness direction of the end cap 227.

[0105] Please see Figure 14 In some embodiments, the ratio of the distance R3 between the first end 31 and the rotation center O1 of the impeller 12 to the outlet diameter D2 of the impeller 12 is: 0.35≤R3 / D2≤0.39, and the line m connecting the first end 31 and the rotation center O1 of the impeller 12 and the line n connecting the first end 31 and the volute tongue of the volute body 22 form an angle β, the range of which is: 50°<β<60°.

[0106] In this way, by setting the first end 31 at a reasonable position on the circumference of the impeller 12, the position of the airflow is avoided, ensuring that the pressure fluctuation at the pressure tapping point is small, and the obtained air pressure is not likely to exceed the negative pressure range when the external static pressure fluctuates greatly.

[0107] Specifically, such as Figure 14 As shown, when the impeller 12 is placed vertically, the axial direction of the impeller 12 remains horizontal (the direction through the paper), and the vertical direction is vertical. The volute tongue of the volute body 22 refers to the transition fillet between the starting point of the spiral line of the volute body 22 and the cylindrical outline forming the air outlet 2033, that is, the connection between the curved part and the lower edge of the outlet part. The distance R3 between the first end 31 and the rotation center O1 of the impeller 12 is the length of the line segment connecting the center of the through hole 311 formed on the end cover 227 of the first end 31 and the rotation center O1 of the impeller 12. The position of the first end 31 on the volute body 22 is determined by the ratio R3 / D2 of the distance R3 and the outlet diameter D2 of the impeller 12, and the angle β formed by the connecting line m and the vertical line n, that is, the point at which the pressure tapping structure 30 taps pressure in the receiving cavity 201 is determined.

[0108] In a preferred embodiment, the ratio of the distance R3 between the first end 31 and the rotation center O1 of the impeller 12 to the outlet diameter D2 of the impeller 12 is R3 / D2 = 0.3725, and β = 56°.

[0109] Please refer to it again. Figure 1This application provides a gas furnace 1000, which includes a flue gas exhaust device 100 and a burner 200 according to any of the above embodiments. The burner 200 is used to provide a carrier for fuel combustion, and the flue gas exhaust device 100 is used to discharge combustion exhaust gas.

[0110] The gas furnace 1000 of this application embodiment has all the beneficial effects of the smoke exhaust device 100 of any of the above embodiments because it includes the smoke exhaust device 100 of the present application embodiment.

[0111] Specifically, the gas furnace 1000 is a type of heating device that generates hot air through the combustion of fuels such as natural gas, which then exchanges heat with the environment. The exhaust device 100 introduces fresh air into the gas furnace 1000 and exhausts the combustion exhaust gas after heat exchange. Typically, the exhaust outlet 203 of the exhaust device 100 is connected to the flue pipe 40, through which the combustion exhaust gas is discharged outdoors. When the exhaust outlet of the flue pipe 40 is exposed to strong winds or the flue pipe 40 is long, the external static pressure of the exhaust device 100 is relatively high. The exhaust device 100 of this embodiment adopts a forward centrifugal impeller 12 and optimizes the impeller 12 parameters, thereby improving the pressure resistance of the exhaust device 100 and increasing the external static pressure. This expands the operating range of the gas furnace 1000, ensures safe and efficient combustion of the gas furnace 1000, and simultaneously reduces noise.

[0112] In a preferred embodiment, the external static pressure can be increased from 230Pa to 600Pa, and the maximum speed n of the fan assembly 10 is ≤3500rpm, ensuring the structural strength of the impeller 12. At the same time, the noise is reduced by 7-16dB(A) compared to the exhaust fan with the same air volume, further reducing noise pollution and improving the user experience.

[0113] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer 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.

[0114] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A flue gas extraction device for a gas-fired furnace, characterized in that, The smoke extraction device includes: A fan assembly, comprising a motor and an impeller, wherein the impeller comprises a plurality of arc-shaped blades arranged at intervals along the circumference of the impeller, and the motor is used to drive the impeller to rotate to form an airflow flowing in a preset direction; A volute assembly forms a receiving cavity and an air inlet and an air outlet communicating with the receiving cavity. An impeller is housed in the receiving cavity, the rotation center of the impeller is located at the air inlet, and the air outlet is located on one side of the volute assembly along the radial direction of the impeller. The ratio of the chord length L of the blade to the radius R of the impeller conforms to the following: 0.49≤L / R≤0.56 The ratio of the impeller inlet diameter D1 to the impeller outlet diameter D2 conforms to the following: 0.48≤D1 / D2≤0.62, The ratio of the axial width H of the impeller to the outlet diameter D2 of the impeller conforms to the following: 0.16≤H / D2≤0.

26.

2. The smoke extraction device according to claim 1, characterized in that, The exit angle of the blade is an obtuse angle.

3. The smoke extraction device according to claim 2, characterized in that, The exit angle of the blade is in the range of 159°±9°, and / or the inlet angle of the blade is in the range of 90°±5°.

4. The smoke extraction device according to claim 1, characterized in that, The impeller includes a chassis and a frame coaxial with the impeller. The chassis is located on one side of the impeller axis and covers the blades. The ends of the blades away from the air inlet extend out of the chassis. The frame is located on the side of the impeller axis opposite to the chassis and covers the ends of the blades away from the air inlet. The ratio of the outer diameter D4 of the chassis to the outlet diameter D2 of the impeller is: 0.48≤D4 / D2≤0.

62.

5. The smoke extraction device according to claim 4, characterized in that, The inner diameter D6 of the frame and the outer diameter D4 of the chassis have the following relationship: D6≥D4; The outer diameter D5 of the frame and the outlet diameter D2 of the impeller have the following relationship: 0.98*D2<D5<1.02*D2.

6. The smoke extraction device according to claim 4, characterized in that, The impeller also includes a fastener that passes through the center of the chassis along the axial direction of the impeller. The chassis includes a protective member that covers the end of the fastener facing the frame.

7. The smoke extraction device according to claim 1, characterized in that, The volute assembly includes a volute body, the volute body includes a curved portion and an outlet portion connecting the curved portion, the curved portion covers the impeller, the outlet portion forms the air outlet, and the upper edge of the outlet portion is connected to the top of the curved portion; The ratio of the vertical distance H1 from the lower edge of the outlet to the center of rotation of the impeller to the height H2 of the volute body is: 0.23≤H1 / H2≤0.

3.

8. The smoke extraction device according to claim 7, characterized in that, The ratio of the opening degree A of the volute body to the height H2 of the volute body conforms to the following condition: 0.125≤A / H2≤0.145, and the spiral initiation angle θ of the volute body is in the range of 59°<θ<63°.

9. The smoke extraction device according to claim 1, characterized in that, The volute assembly includes a volute body, on which a pressure-taking structure communicating with the receiving cavity is provided. The pressure-taking structure includes a first end near the air inlet and a second end away from the air inlet, with the first end located near the air inlet.

10. The smoke extraction device according to claim 9, characterized in that, The ratio of the distance R3 between the first end and the rotation center of the impeller to the outlet diameter D2 of the impeller is: 0.35≤R3 / D2≤0.39, and the line connecting the first end and the rotation center of the impeller forms an angle β with the line connecting the first end and the volute tongue of the volute body, wherein the angle β is in the range of: 50°<β<60°.

11. A gas-fired stove, characterized in that, The gas furnace includes a flue gas exhaust device and a burner as described in any one of claims 1-10, wherein the burner is used to provide a carrier for fuel combustion, and the flue gas exhaust device is used to discharge combustion exhaust gases.

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