EXHAUST DEVICE AND GAS FURNACE

Abstract

An exhaust device includes a fan assembly and a volute assembly. The fan assembly includes an impeller including blades arranged at intervals in a circumferential direction of the impeller and each being of an arc shape, and a motor configured to drive the impeller to rotate to form an air flow. The volute assembly has a receiving cavity, and an air inlet and an air outlet in communication with the receiving cavity. The impeller is received in the receiving cavity. A rotation center of the impeller is located at the air inlet. The air outlet is located at a side of the volute assembly in a radial direction of the impeller. A chord length L of each of the plurality of blades, and a radius R, an inlet diameter D1, an outlet diameter D2, an axial width H of the impeller satisfy: 0.49L/R0.56, 0.48D1/D20.62, and 0.16H/D20.26.

Claims

1. An exhaust device comprising: a fan assembly including: an impeller including a plurality of blades arranged at intervals in a circumferential direction of the impeller, each of the plurality of blades being of an arc shape; and a motor configured to drive the impeller to rotate to form an air flow flowing in a predetermined direction; and a volute assembly having a receiving cavity, and an air inlet and an air outlet in communication with the receiving cavity; wherein: the impeller is received in the receiving cavity, a rotation center of the impeller is located at the air inlet, and the air outlet is located at a side of the volute assembly in a radial direction of the impeller; a ratio of a chord length L of each of the plurality of blades to a radius R of the impeller satisfies: 0.49L/R0.56; a ratio of an inlet diameter D1 of the impeller to an outlet diameter D2 of the impeller satisfies: 0.48D1/D20.62; and a ratio of an axial width H of the impeller to the outlet diameter D2 of the impeller satisfies: 0.16H/D20.26.

2. The exhaust device according to claim 1, wherein an outlet angle of the blade is an obtuse angle.

3. The exhaust device according to claim 2, wherein the outlet angle of the blade ranges from 150 to 168.

4. The exhaust device according to claim 1, wherein an inlet angle of the blade ranges from 85 to 95.

5. The exhaust device according to claim 1, wherein: the impeller includes a base and a frame that are coaxial with the impeller; the base is located at a side of the impeller in an axial direction of the impeller, and covers the plurality of blades, an end of the blade away from the air inlet extends out of the base; and the frame is arranged at a side of the impeller opposite to the base in the axial direction of the impeller, and covers the end of the blade away from the air inlet; and a ratio of an outer diameter D4 of the base to the outlet diameter D2 of the impeller satisfies: 0.48D4/D20.62.

6. The exhaust device according to claim 5, wherein: an inner diameter D6 of the frame and the outer diameter D4 of the base satisfy: D6D4; and an outer diameter D5 of the frame and the outlet diameter D2 of the impeller satisfy: 0.98*D2<D5<1.02*D2.

7. The exhaust device according to claim 5, wherein: the impeller further includes a fastener axially extending through a center of the base; and the base includes a protection part covering an end of the fastener facing towards the frame.

8. The exhaust device according to claim 1, wherein: the volute assembly includes a volute body including a curved member and an outlet member connected to the curved member; the impeller is covered by the curved member, the air outlet is formed at the outlet member, and the outlet member is connected to a top end of the curved member at an upper edge of the outlet member; and a ratio of a vertical distance H1 from a lower edge of the outlet member to the rotation center of the impeller to a height H2 of the volute body satisfies: 0.23H1/H20.3.

9. The exhaust device according to claim 8, wherein: a ratio of an opening degree A of the volute body to the height H2 of the volute body satisfies: 0.125A/H20.145; and a spiral starting angle of the volute body ranges from 59 to 63.

10. The exhaust device according to claim 1, wherein the volute assembly includes a volute body provided with a pressure tapping structure in communication with the receiving cavity, and the pressure tapping structure has a first end close to the air inlet and a second end away from the air inlet.

11. The exhaust device according to claim 10, wherein: a ratio of a distance R3 between the first end and the rotation center of the impeller to the outlet diameter D2 of the impeller satisfies: 0.35R3/D20.39; and an angle between a connection line from the first end to the rotation center of the impeller and a connection line from the first end to a volute tongue of the volute body ranges from 50 to 60.

12. A gas furnace comprising: a burner configured for fuel combustion; and a exhaust device configured to discharge combustion exhaust gas and including: a fan assembly including: an impeller including a plurality of blades arranged at intervals in a circumferential direction of the impeller, each of the plurality of blades being of an arc shape; and a motor configured to drive the impeller to rotate to form an air flow flowing in a predetermined direction; and a volute assembly having a receiving cavity, and an air inlet and an air outlet in communication with the receiving cavity; wherein: the impeller is received in the receiving cavity, a rotation center of the impeller is located at the air inlet, and the air outlet is located at a side of the volute assembly in a radial direction of the impeller; a ratio of a chord length L of each of the plurality of blades to a radius R of the impeller satisfies: 0.49L/R0.56; a ratio of an inlet diameter D1 of the impeller to an outlet diameter D2 of the impeller satisfies: 0.48D1/D20.62; and a ratio of an axial width H of the impeller to the outlet diameter D2 of the impeller satisfies: 0.16H/D20.26.

13. The gas furnace according to claim 12, wherein an outlet angle of the blade is an obtuse angle.

14. The gas furnace according to claim 13, wherein the outlet angle of the blade ranges from 150 to 168.

15. The gas furnace according to claim 12, wherein an inlet angle of the blade ranges from 85 to 95.

16. The gas furnace according to claim 12, wherein: the impeller includes a base and a frame that are coaxial with the impeller; the base is located at a side of the impeller in an axial direction of the impeller, and covers the plurality of blades, an end of the blade away from the air inlet extends out of the base; and the frame is arranged at a side of the impeller opposite to the base in the axial direction of the impeller, and covers the end of the blade away from the air inlet; and a ratio of an outer diameter D4 of the base to the outlet diameter D2 of the impeller satisfies: 0.48D4/D20.62.

17. The gas furnace according to claim 16, wherein: an inner diameter D6 of the frame and the outer diameter D4 of the base satisfy: D6D4; and an outer diameter D5 of the frame and the outlet diameter D2 of the impeller satisfy: 0.98*D2<D5<1.02*D2.

18. The gas furnace according to claim 16, wherein: the impeller further includes a fastener axially extending through a center of the base; and the base includes a protection part covering an end of the fastener facing towards the frame.

19. The gas furnace according to claim 12, wherein: the volute assembly includes a volute body including a curved member and an outlet member connected to the curved member; the impeller is covered by the curved member, the air outlet is formed at the outlet member, and the outlet member is connected to a top end of the curved member at an upper edge of the outlet member; and a ratio of a vertical distance H1 from a lower edge of the outlet member to the rotation center of the impeller to a height H2 of the volute body satisfies: 0.23H1/H20.3.

20. The gas furnace according to claim 19, wherein: a ratio of an opening degree A of the volute body to the height H2 of the volute body satisfies: 0.125A/H20.145; and a spiral starting angle of the volute body ranges from 59 to 63.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and/or additional aspects and advantages of the present disclosure will become more apparent and more understandable from the following description of embodiments taken in conjunction with the accompanying drawings, in which:

[0029] FIG. 1 is a schematic structural view of a gas furnace according to some embodiments of the present disclosure.

[0030] FIG. 2 is a schematic structural view of an exhaust device according to some embodiments of the present disclosure.

[0031] FIG. 3 is a schematic cross-sectional structural view of an exhaust device according to some embodiments of the present disclosure.

[0032] FIG. 4 is a schematic exploded structural view of an exhaust device according to some embodiments of the present disclosure.

[0033] FIG. 5 is a schematic view of a movement trajectory of a blade according to some embodiments of the present disclosure.

[0034] FIG. 6 is a schematic structural view of an impeller according to some embodiments of the present disclosure.

[0035] FIG. 7 is a schematic structural view of an impeller in a rear view according to some embodiments of the present disclosure.

[0036] FIG. 8 is a schematic structural view of an impeller in a left view according to some embodiments of the present disclosure.

[0037] FIG. 9 is a schematic structural view of an impeller in a front view according to some embodiments of the present disclosure.

[0038] FIG. 10 is a schematic cross-sectional structural view of an exhaust device without a motor according to some embodiments of the present disclosure.

[0039] FIG. 11 is a schematic structural view of a volute body according to some embodiments of the present disclosure.

[0040] FIG. 12 is a schematic view showing a position of an impeller in a volute body according to some embodiments of the present disclosure.

[0041] FIG. 13 is a schematic structural view of a volute body in a rear view according to some embodiments of the present disclosure.

[0042] FIG. 14 is a schematic structural view of an end cover in a front view according to some embodiments of the present disclosure.

[0043] Description of reference numerals:

[0044] 1000, gas furnace; 100, exhaust device; 10, fan assembly; 11, motor; 112, transmission shaft; 12, impeller; 121, blade; 122, base; 123, frame; 124, fastener; 125, protection part; 20, volute assembly; 201, receiving cavity; 202, air inlet; 203, air outlet; 21, support; 22, volute body; 221, curved member; 223, outlet member; 222, main body; 225, bottom plate; 226, enclosing plate; 227, end cover; 30, pressure tapping structure; 31, first end; 311, through hole; 32, second end; 40, fume pipe; 200, burner.

DETAILED DESCRIPTION

[0045] The embodiments of the present disclosure will be described in detail below with reference to examples thereof as illustrated in the accompanying drawings, throughout which same or similar elements, or elements having same or similar functions, are denoted by same or similar reference numerals. The embodiments described below with reference to the drawings are illustrative only, and are intended to explain, rather than limiting, the embodiments of the present disclosure.

[0046] In the description of the embodiments of the present disclosure, it should be understood that, the orientation or the position indicated by terms such as center, longitudinal, lateral, length, width, thickness, over, below, front, rear, left, right, vertical, horizontal, top, bottom, inner, outer, clockwise, and counter-clockwise should be construed to refer to the orientation and the position as shown in the drawings, and is only for the convenience of describing the embodiments of the present disclosure and simplifying the description, rather than indicating or implying that the pointed device or element must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the embodiments of the present disclosure. In addition, the terms first and second are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features associated with first and second may explicitly or implicitly include at least one of the features. In the description of the embodiments of the present disclosure, plurality of means at least two, such as two, three, etc., unless otherwise specifically defined.

[0047] In the description of the embodiments of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, terms such as install, connect, connect to, and the like should be understood in a broad sense. For example, it may be a fixed connection or a detachable connection or connection as one piece; mechanical connection or electrical connection or connection enabling mutual communication; direct connection or indirect connection through an intermediate; internal communication of two components or the interaction relationship between two components. For those skilled in the art, the specific meaning of the above-mentioned terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0048] In the embodiments of the present disclosure, unless expressly stipulated and defined otherwise, the first feature on or under the second feature may mean that the first feature is in direct contact with the second feature, or the first and second features are in indirect contact through an intermediate. Moreover, the first feature above the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply mean that the level of the first feature is higher than that of the second feature. The first feature below the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply mean that the level of the first feature is smaller than that of the second feature.

[0049] Various embodiments or examples for implementing different structures of the embodiments of the present disclosure are provided below. In order to simplify the description of the embodiments of the present disclosure, components and configurations of specific examples are described below. These specific examples are merely for the purpose of illustration, rather than limiting the present disclosure. Further, the same reference numerals and/or reference letters may appear in different examples of the embodiments of the present disclosure for the purpose of simplicity and clarity, instead of indicating a relationship between different embodiments and/or the discussed configurations. In addition, the embodiments of the present disclosure provide examples of various specific processes and materials. However, applications of other processes and/or the use of other materials are conceivable for those of ordinary skill in the art.

[0050] Referring to FIG. 1 to FIG. 5, the present disclosure provides an exhaust device 100 for a gas furnace 1000. The 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 blades 121 arranged at intervals in a circumferential direction of the impeller 12. Each of the plurality of blades 121 is of an arc shape. The motor 11 is configured to drive the impeller 12 to rotate to form an air flow flowing in a predetermined direction. The volute assembly 20 has a receiving cavity 201, an air inlet 202, and an air outlet 203. Each of the air inlet 202 and the air outlet 203 is in communication with the receiving cavity 201. The impeller 12 is received in the receiving cavity 201. A rotation center O1 of the impeller 12 is located at the air inlet 202, and the air outlet 203 is located at a side of the volute assembly 20 in a radial direction of the impeller 12.

[0051] A ratio of a chord length L of each of the plurality of blades 121 to a radius R of the impeller 12 satisfies: 0.49L/R0.56.

[0052] A ratio of an inlet diameter D1 of the impeller 12 to an outlet diameter D2 of the impeller 12 satisfies: 0.48D1/D20.62.

[0053] A ratio of an axial width H of the impeller 12 to the outlet diameter D2 of the impeller 12 satisfies: 0.16H/D20.26.

[0054] In the exhaust device 100 according to the embodiments of the present disclosure, by designing the blade 121 into a large chord length structure and optimizing the ratio of the inlet diameter to the outlet diameter of the impeller 12 as well as the ratio of the axial width to the outlet diameter of the impeller 12, adaptability of the exhaust device 100 to an external static pressure is improved, the static pressure is increased, and high pressure resistance performance of an exhaust fan is further improved, enabling the exhaust fan to adapt to more complex operating conditions.

[0055] In an exemplary embodiment of the present disclosure, the exhaust device 100 is in a volute shape as a whole. An inner wall surface of the volute assembly 20 encloses the receiving cavity 201. The motor 11 may be arranged on the volute assembly 20 and located at a side opposite to the air inlet 202. The motor 11 includes a transmission shaft 112 connected to the impeller 12 and forming the rotation center O1 of the impeller 12. The transmission shaft 112 penetrates a wall surface of the volute assembly 20 in an axial direction of the impeller 12 towards the air inlet 202, which allows an end of the transmission shaft 112 to extend into the volute assembly 20.

[0056] In another exemplary embodiment of the present disclosure, the volute assembly 20 further includes a support 21 fixedly connected to the motor 11, to stably mount the motor 11 on the volute assembly 20.

[0057] In the circumferential direction of the impeller 12, a surface of the blade 121 protrudes into an arc-shaped curved surface, and a rotation direction of the impeller 12 is opposite to a protruding direction of the arc-shaped surface of the blade 121. Arc-shaped curved surfaces of two adjacent blades 121 are opposite and spaced in the circumferential direction of the impeller 12. Moreover, a shape and size of a spacing between every two adjacent blades 121 are the same.

[0058] When the axial direction of the impeller 12 is horizontal, FIG. 5 shows a projection of one blade 121 in a horizontal direction, and a projection plane is a vertical plane perpendicular to the axial direction of the impeller 12. A contour shape of the blade 121 may be a part of a circle with a center point O1 as shown in FIG. 5. The chord length L of the blade 121 is a straight-line distance between a top end A and a tail end B of the blade 121. In the radial direction of the impeller 12, the top end A of the blade 121 is located at an inner periphery of the impeller 12, and the tail end B of the blade 121 is located at an outer periphery of the impeller 12. The top end A of the blade 121 is closer to the rotation center O1 of the impeller 12 than the tail end B.

[0059] When the impeller 12 is driven by the motor 11 to rotate, a negative pressure is formed at the air inlet 202. The air flow enters the receiving cavity 201 from the air inlet 202 in the axial direction of the impeller 12 and is discharged from the air outlet 203 in the radial direction of the impeller 12. The top end A and the tail end B of the blade 121 form a movement trajectory and a movement trajectory as shown in FIG. 5, respectively. Both the movement trajectory and the movement trajectory are circular and are concentric circles with the rotation center O1 of the impeller 12 as their center points. It is easy to understand that a diameter of the movement trajectory is the inlet diameter D1 of the impeller 12, and a diameter of the movement trajectory is the outlet diameter D2 of the impeller 12. A radius of the movement trajectory is the radius R of the impeller 12, i.e., a distance between the rotation center O1 of the impeller 12 and the tail end B.

[0060] Exemplarily, the ratio of the chord length L of the blade 121 to the radius R of the impeller 12 may be 0.49, 0.5, 0.52, 0.55, or 0.56. For another example, D1/D2 may be 0.48, 0.5, 0.56, 0.57, 0.6, or 0.62. For another example, H/D2 may be 0.16, 0.18, 0.21, 0.225, or 0.26. In one embodiment, the ratio of the chord length L of the blade 121 to the radius R of the impeller 12, the ratio of the inlet diameter D1 of the impeller 12 to the outlet diameter D2 of the impeller 12, and the ratio of the axial width H of the impeller 12 to the outlet diameter D2 of the impeller 12 may be set to L/R=0.53, D1/D2=0.545, and H/D2=0.22, respectively.

[0061] In another exemplary embodiment of the present disclosure, the number of blades 121 is in a range from 51 to 67. For example, the number of blades 121 may be 51, 53, 56, 65, or 67. In one embodiment, the number of blades 121 is 61.

[0062] Referring to FIG. 5 and FIG. 6, in some embodiments, an outlet angle 1 of the blade 121 is an obtuse angle.

[0063] In this way, since the outlet angle 1 of the blade 121 is the obtuse angle, and the impeller 12 is a forward centrifugal impeller 12. Compared with backward impellers 12 used in most centrifugal fans, under one flow rate and total pressure, a rotation speed and a physical size of the impeller 12 are smaller, which is beneficial to a reduction in noise.

[0064] In an exemplary embodiment of the present disclosure, as shown in FIG. 5, the outlet angle 1 of the blade 121 is an angle between an extending line of the blade 121 at the tail end B towards the outer periphery and a reverse direction of a tangent to a rotation direction of the tail end B. The outlet angle 1 being the obtuse angle means that the angle between the extending line of the blade 121 at the tail end B and the reverse direction of the tangent to the rotation direction is greater than 90.

[0065] Referring to FIG. 5, in some embodiments, the outlet angle 1of the blade 121 ranges from 150 to 168; and/or an inlet angle 2 of the blade 121 ranges from 85 to 95.

[0066] In this way, by setting the outlet angle 1 and/or the inlet angle 2 of the blade 121 within a reasonable range, a smooth inflow of the air flow into the impeller 12 and smooth discharge of the air flow out of the impeller 12 are ensured, which reduces resistance loss, improves an air volume and the static pressure, and can further reduce the noise.

[0067] In an exemplary embodiment of the present disclosure, referring to FIG. 4, the inlet angle 2 is an angle between the gas and the normal to a surface of the impeller 12 when the gas enters the impeller 12 in the exhaust device 100. In one embodiment, the outlet angle 1 and the inlet angle 2 of the blade 121 are designed to be 1=159 and 2=90, respectively.

[0068] Referring to FIG. 6 to FIG. 9, in some embodiments, the impeller 12 includes a base 122 and a frame 123. Both of the base 122 and the frame 123 are coaxial with the impeller 12. The base 122 is located at a side of the impeller 12 in an axial direction of the impeller 12 and covers the plurality of blades 121. An end of the blade 121 away from the air inlet 202 extends out of the base 122. The frame 123 is arranged at a side of the impeller 12 opposite to the base 122 in the axial direction of the impeller 12, and covers the end of the blade 121 away from the air inlet 202.

[0069] A ratio of an outer diameter D4 of the base 122 to the outlet diameter D2 of the impeller 12 satisfies: 0.48D4/D20.62.

[0070] In this way, by designing a reasonable ratio of the outer diameter D4 of the base 122 to the outlet diameter D2 of the impeller 12, a strength of the frame 123 of the impeller 12, a structural strength of the base 122, and an impact on the noise are balanced, achieving a comprehensive effect of a better structural strength and lower noise.

[0071] In an exemplary embodiment of the present disclosure, both the base 122 and the frame 123 are annular. The blades 121 are each fixedly connected to the base 122. The plurality of blades 121 are arranged at uniform intervals in a circumferential direction on the base 122. A via hole is formed at a center of the base 122, allowing for mounting of a shaft sleeve.

[0072] The frame 123 is in the shape of a thin ring and only covers end surfaces of a part of the blades 121. The frame 123 is configured to improve a structural strength of the blade 121, while preventing the air flow discharged from the air outlet 203 from flowing back to the air inlet 202. Both an inner diameter and an outer diameter of the frame 123 are close to the outlet diameter D2 of the blade 121. An end of the blade 121 away from the air outlet 203 extends out of the base 122, i.e., the outlet diameter D2 of the blade 121 is greater than the outer diameter D4 of the base 122, where D2>D4.

[0073] It should be noted that as the outer diameter of the base 122 decreases, the noise increases; while as the inner diameter of the frame 123 increases, the strength of the frame 123 decreases. Therefore, it is needed to reasonably design a ratio of the outer diameter D5 to the inner diameter D6 of the frame 123 and a ratio of the outer diameter of the base 122 to the outlet diameter of the blade 121, to balance the comprehensive effect of the structural strength and the noise.

[0074] In one embodiment, D4/D2=0.545.

[0075] Referring to FIG. 6 to FIG. 9, in some embodiments, an inner diameter D6 of the frame 123 and the outer diameter D4 of the base 122 satisfies: D6D4.

[0076] An outer diameter D5 of the frame 123 and the outlet diameter D2 of the impeller 12 satisfies: 0.98*D2<D5<1.02*D2.

[0077] In this way, by designing the inner diameter D6 of the frame 123 to be greater than or equal to the outer diameter D4 of the base 122, mold design is facilitated, one-time demolding is realized, and production efficiency of the impeller 12 product is improved. By designing the ratio of the outer diameter D5 of the frame 123 to the outlet diameter D2 to be close to 1:1, a draft angle is made relatively small, reducing a difference between the mold part and the designed part.

[0078] In an exemplary embodiment of the present disclosure, the outer diameter D5 of the frame 123 is slightly greater than the inner diameter D6 of the frame 123. Therefore, D5>D6D4.

[0079] In one embodiment, the outer diameter D5 of the frame 123 is equal to the outlet diameter D2 of the impeller 12, i.e., D5=D2. In this embodiment, D2=D5>D6D4.

[0080] Referring to FIG. 10, in some embodiments, the impeller 12 further includes a fastener 124 axially extending through a center of the base 122. The base 122 includes a protection part 125 covering an end of the fastener 124 facing towards the frame 123.

[0081] In this way, by covering the end of the fastener 124 facing towards the frame 123 with the protection part 125, corrosion of a motor 11 shaft and the fastener 124 by acidic condensed water generated after combustion in the gas furnace 100 is prevented.

[0082] In an exemplary embodiment of the present disclosure, the fastener 124 may be a fastening nut extending through the via hole at the center of the base 122. The protection part 125 may be made of a material with good covering and corrosion resistance, such as plastic.

[0083] Referring to FIG. 10 to FIG. 12, in some embodiments, the volute assembly 20 includes a volute body 22. The volute body 22 includes a curved member 221 and an outlet member 223 connected to the curved member 221. The impeller 12 is covered by the curved member 221. The air outlet 203 is formed at the outlet member 223, and the outlet member 223 is connected to a top end of the curved member 221 at an upper edge of the outlet member 223. A ratio of a vertical distance H1 from a lower edge of the outlet member 223 to the rotation center O1 of the impeller 12 to a height H2 of the volute body 22 satisfies: 0.23H1/H20.3.

[0084] In this way, by setting the ratio of H1 from the lower edge of the outlet member 223 to the rotation center O1 of the impeller 12 to the height H2 of the volute body 22 within a reasonable range, adaptability between a volute curve and the impeller 12 is improved, which is beneficial to uniform discharge of the air flow in the circumferential direction of the impeller 12 and an uniform inflow of the air flow into the receiving cavity 201, achieving an effect of stable and uniform flow.

[0085] In an exemplary embodiment of the present disclosure, when the exhaust device 100 is placed vertically, the axial direction of the impeller 12 remains horizontal. A direction from the upper edge to the lower edge of the outlet member 223 (an up-down direction as shown in the drawings) is a vertical direction. Heights of the impeller 12 and the volute assembly 20 are measured in the up-down direction. In one embodiment, H1/H2=0.27.

[0086] With reference to FIG. 2 and FIG. 3, an outer contour of the curved member 221 is a spiral profile. The outlet member 223 is approximately cylindrical. Both the curved member 221 and the outlet member 223 are hollow structures and in communication with each other. The curved member 221 forms the receiving cavity 201 and the air inlet 202. The impeller 12 is received in the curved member 221. One of two sides of the curved member 221 in the axial direction of the impeller 12 has the air inlet 202, and another one of the two sides of the curved member 221 in the axial direction of the impeller 12 is provided with the motor 11. The transmission shaft 112 of the motor 11 passes through a side wall surface of the curved member 221 and extends into the receiving cavity 201.

[0087] It should be noted that the curved member 221 and the main body 222 are two parts of the volute body 22 with different contour profiles, and should not be regarded as two separate parts. The curved member 221 and the main body 222 may be integrally connected or assembled from a plurality of separate components. For example, the volute body 22 includes a main body 222 and an end cover 227 arranged separately. A side of the main body 222 in the axial direction of the impeller 12 has an opening, and the end cover 227 covers the opening of the main body 222. The main body 222 includes a bottom plate 225 opposite to the end cover 227 in the axial direction of the impeller 12 and an enclosing plate 226. The enclosing plate 226 is connected to the end cover 227 and surrounds the impeller 12 for a full circle in the circumferential direction of the impeller 12. Partial contours of the main body 222 and the end cover 227 are spiral profiles. The parts of the main body 222 and the end cover 227 with spiral profiles together form the curved member 221.

[0088] Referring to FIG. 12, in some embodiments, a ratio of an opening degree A of the volute body 22 to the height H2 of the volute body 22 satisfies: 0.125A/H20.145, and a spiral starting angle of the volute body 22 ranges from 59 to 63.

[0089] In this way, 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 of the volute body 22 within predetermined ranges, a volute profile adapted to the impeller 12 is formed, which allows gas to be uniformly discharged along a circumference of the impeller 12 and to enter the receiving cavity 201, achieving the effect of stable and uniform flow, and improving low-noise and high-efficiency performance of the exhaust device 100.

[0090] In an exemplary embodiment of the present disclosure, when the exhaust device 100 is placed vertically, the axial direction of the impeller 12 remains horizontal. The up-down direction as shown in the drawings is the vertical direction. A spiral center of the volute body 22 overlaps with a projection of the rotation center O1 of the impeller 12 in the horizontal direction. The spiral starting angle is an angle of a starting cross-section of the volute profile with respect to the up-down direction.

[0091] The opening degree A refers to a width of a final cross-section. The final cross-section of the volute profile is an outlet cross-section for gas leaving the impeller 12. As shown in FIG. 12, the opening degree A may also be a width of a cross-section where the spiral profile of the curved member 221 is connected to the outlet member 223.

[0092] In one embodiment, A/H2=0.136 and =61. The volute body 22 guides the gas leaving the impeller 12 to the air outlet 203 and converts part of kinetic energy of the gas into the static pressure. By optimizing the design of an opening degree A of the final cross-section and the starting cross-section, flow loss of the gas can be reduced, and aerodynamic performance of the impeller 12 can be improved.

[0093] Referring to FIG. 10 and FIG. 13, in some embodiments, the volute assembly 20 includes a volute body 22 provided with a pressure tapping structure 30 in communication with the receiving cavity 201. The pressure tapping structure 30 has a first end 31 close to the air inlet 202 and a second end 32 away from the air inlet 202. The first end 31 is arranged close to the air inlet 202.

[0094] In this way, by arranging the pressure tapping structure 30 in communication with the receiving cavity 201, a real-time air pressure is detected through pressure tapping from the first end 31, facilitating control of a rotation speed of the motor 11 through the real-time air pressure.

[0095] In an exemplary embodiment of the present disclosure, the pressure tapping structure 30 may be a hollow tube. The first end 31 is connected to a side of the volute body 22 and in communication with the receiving cavity 201. The second end 32 may extend out of the volute body 22. The pressure tapping structure 30 is connected to a negative pressure detection device (not shown) through the second end 32 to feed back the real-time air pressure in the receiving cavity 201. The motor 11 may adjust its rotation speed based on the real-time air pressure obtained by the pressure tapping structure 30 to ensure a stable air volume, further realizing self-adaption of the motor 11 to the external static pressure.

[0096] In another exemplary embodiment of the present disclosure, in an example, the volute body 22 includes a bottom plate 225, an end cover 227, and an enclosing plate 226. The bottom plate 225 is opposite to the end cover 227 in the axial direction of the impeller 12. The enclosing plate 226 is connected to the bottom plate 225 and the end cover 227, and surrounds the impeller 12 for a full circle in the circumferential direction of the impeller 12. An air inlet 202 is formed at a center of the end cover 227, and a through opening is formed at a center of the bottom plate 225. The transmission shaft 112 of the motor 11 passes through the through opening, extends into the volute body 22, and is connected to the impeller 12. The pressure tapping structure 30 is arranged on the end cover 227. The first end 31 has a through hole 311 formed thereon, and penetrates the end cover 227 in a thickness direction of the end cover 227.

[0097] Referring to FIG. 14, in some embodiments, a ratio of a 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 satisfies: 0.35R3/D20.39. Moreover, an angle is formed between a connection line m from the first end 31 to the rotation center O1 of the impeller 12 and a connection n line from the first end 31 to a volute tongue of the volute body 22. The angle ranges from 50 to 60.

[0098] In this way, by setting the first end 31 at a reasonable position on the circumference of the impeller 12, a position where the air flow is relatively turbulent is avoided, a pressure fluctuation at a pressure tapping position is ensured to be small, and the obtained air pressure is not easy to exceed a negative pressure range when the external static pressure fluctuates greatly.

[0099] In an exemplary embodiment of the present disclosure, as shown in FIG. 14, when the impeller 12 is placed vertically, its axial direction remains horizontal (a direction passing through the paper), and the up-down direction is the vertical direction. The volute tongue of the volute body 22 refers to a transition fillet between a starting point of the spiral profile of the volute body 22 and a cylindrical contour line forming the air outlet 203, i.e., a connection between the curved member and the lower edge of the outlet member. The distance R3 between the first end 31 and the rotation center O1 of the impeller 12 is a length of a connection line segment from a center of the through hole 311 formed by the first end 31 on the end cover 227 and the rotation center O1 of the impeller 12. The position of the first end 31 on the volute body 22, i.e., a pressure tapping point of the pressure tapping structure 30 in the receiving cavity 201 is determined by the ratio R3/D2 of the distance R3 to the outlet diameter D2 of the impeller 12 and the angle formed between the connection line m and the vertical line n.

[0100] In one embodiment, the ratio R3/D2 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 0.3725, where =56.

[0101] Referring to FIG. 1, the present disclosure provides a gas furnace 1000. The gas furnace 1000 includes the exhaust device 100 according to any of the above embodiments and a burner 200. The burner 200 is configured to provide a carrier for fuel combustion, and the exhaust device 100 is configured to discharge combustion exhaust gas.

[0102] The gas furnace 1000 according to the embodiments of the present disclosure, because it includes the exhaust device 100 according to any one of the above embodiments, has all the beneficial effects of the exhaust device 100 according to the embodiments of the present disclosure.

[0103] In an exemplary embodiment of the present disclosure, the gas furnace 1000 is a type of heating device that generates hot air through combustion of fuels such as natural gas to exchange heat with the environment. The exhaust device 100 may introduce fresh air into the gas furnace 1000 and discharge the combustion exhaust gas after the heat exchange. Typically, the air outlet 203 of the exhaust device 100 is connected to a fume pipe 40. The combustion exhaust gas is discharged to the outside through the fume pipe 40. When an exhaust port of the fume pipe 40 is directly blown by strong wind or the fume pipe 40 is long, the external static pressure of the exhaust device 100 is relatively high. The exhaust device 100 according to the embodiments of the present disclosure adopts a forward centrifugal impeller 12 and optimizes parameters of the impeller 12, which improves pressure resistance performance of the exhaust device 100 and increases the external static pressure. Therefore, an operating condition range of the gas furnace 1000 is expanded, ensuring safe and efficient combustion of the gas furnace 1000, while reducing the noise.

[0104] In one embodiment, the external static pressure may be increased from 230 Pa to 600 Pa, and a maximum rotation speed n of the fan assembly 10 is 3500rpm, which ensures a structural strength of the impeller 12. Meanwhile, compared with exhaust fans with the same air volume, the noise is reduced by 7 dB(A) to 16 dB(A), further reducing noise pollution and improving the user experience.

[0105] In the description of this specification, descriptions with reference to the terms an embodiment, some embodiments, schematic embodiments, examples, specific examples, or some examples, etc. mean that specific features, structure, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner.

[0106] Although the embodiments of the present disclosure according to the present disclosure have been shown and described, it would be appreciated by those skilled in the art that the above embodiments are illustrative and cannot be construed to limitation on the present disclosure, and changes, alternatives, modifications, and variations can be made in the above embodiments without departing from scope of the present disclosure.