Flat air duct structure and refrigerator

Abstract

This invention discloses a flat air duct structure and a freezer, belonging to the field of refrigeration equipment technology. It includes a first air duct housing a centrifugal fan and an evaporator. The air inlet of the evaporator is opposite to the air outlet of the volute. The impeller is offset from the center of the volute, causing the air outlet of the volute to form a narrow and a wide air outlet area. The sidewall of the volute is composed of three interconnected arc-shaped sidewalls: a first arc-shaped sidewall opposite the narrow air outlet area, a second arc-shaped sidewall opposite the wide air outlet area, and a third arc-shaped sidewall. The curve formed by the vertical projection of the first arc-shaped sidewall is a circular arc of a fixed radius. On the narrow air outlet area side, a guide bend is formed on the inner side of the first arc-shaped sidewall. With the cooperation of the first, second, and third arc-shaped sidewalls, the airflow delivered by the impeller is smoothly redirected and evenly diffused towards the evaporator, ensuring the smoothness and uniformity of airflow dispersion, improving the utilization rate of the evaporator, and preventing frost blockage.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, and in particular to a flat air duct structure and a freezer. Background Technology

[0002] Refrigerators use fans to drive air to exchange heat with the evaporator and circulate the air inside the cabinet to achieve cooling. The layout and design of the air duct and related structural components have a significant impact on the key performance of the freezer, such as volume utilization, cooling efficiency, and equipment lifespan.

[0003] In the prior art, in order to reduce the impact of air duct design on the volume of the freezer, a flat layout is adopted for the fan and evaporator. See Chinese utility model patent with publication number CN221279760U, which discloses an air duct assembly for a refrigeration device, including an air duct, an evaporator inside the air duct, and at least two volutes arranged side by side above the air duct, with a centrifugal fan inside the volute; an air inlet is provided on the back of the volute, and an air outlet is provided at the bottom of the air duct; the outer contour of the volute includes a spiral curve centered on the center of the fan, and a first straight line segment and a second straight line segment tangent to the starting point and the ending point of the spiral curve, respectively, and the first straight line segment and the second straight line segment extend to the upper edge of the air duct to form a downward-opening volute opening.

[0004] When the above solutions are applied, the uniformity of air volume and the smoothness of airflow on both sides of the volute air outlet are not good. A small amount of turbulence is likely to occur on one side. When some airflow passes through the high wind resistance area of ​​the evaporator, it is easy to fail to pass due to the exhaustion of the airflow kinetic energy. Especially when applied in freezers with lower temperatures, the problem of frost blockage is more likely to occur due to poor airflow. Summary of the Invention

[0005] In order to overcome the defects of the existing technology, the present invention provides a flat air duct structure and a freezer.

[0006] The technical solution adopted by this invention to solve its technical problem is: a flat air duct structure, comprising: The first air duct contains a centrifugal fan and an evaporator; The centrifugal fan includes an impeller, a motor, and a volute. The air inlet of the evaporator is opposite to the air outlet of the volute, and the airflow sent out by the impeller will enter the evaporator through the air outlet of the volute. The impeller is offset from the center of the volute casing by a distance not greater than the diameter of the impeller, causing the air outlet of the volute casing to form a narrow and a wide air outlet area. The air outlet direction on the side of the impeller closer to the narrow air outlet area gradually moves away from the evaporator, while the air outlet direction on the side of the impeller closer to the wide air outlet area gradually moves towards the evaporator. The sidewall of the volute casing is composed of three arc-shaped sidewalls, including: The first arc-shaped sidewall, opposite to the narrow air outlet area, forms a curve with a fixed radius circular arc by its vertical projection. On one side of the narrow air outlet area, a guide bend is formed on the inner side of the first arc-shaped sidewall. The second arc-shaped sidewall is opposite to the wide air outlet area; The third arc-shaped sidewall is connected to the first arc-shaped sidewall and the second arc-shaped sidewall at both ends, respectively.

[0007] Preferably, the curve formed by the vertical projection of the second arc-shaped sidewall is an Archimedean spiral, and the curve formed by the vertical projection of the third arc-shaped sidewall is a circular arc with a fixed radius. The circle containing the curve formed by the vertical projection of the third arc-shaped sidewall is tangent to the circle containing the curve formed by the vertical projection of the first arc-shaped sidewall; the circle containing the curve formed by the vertical projection of the third arc-shaped sidewall is tangent to the inner curve formed by the vertical projection of the second arc-shaped sidewall, and the point of tangency is the connection point. The curve formed by the vertical projection of the first arc-shaped sidewall extends tangentially towards the wide air outlet area from the end near the impeller and is tangent to the impeller. The other end of the curve formed by the vertical projection of the first arc-shaped sidewall is tangent to the air inlet direction of the evaporator.

[0008] Preferably, the polar coordinate equation of the curve formed by the vertical projection of the second arc-shaped sidewall is: r = |480-341θ|; The range of θ is: 0 ≤ θ ≤ 5 / 18π.

[0009] Preferably, to avoid excessive energy loss of the airflow between the impeller and the third arc-shaped sidewall during the output process, the curve formed by the vertical projection of the third arc-shaped sidewall is not concentric with the impeller. Along the third arc-shaped sidewall, from the first arc-shaped sidewall to the second arc-shaped sidewall, the gap between the outer side of the impeller and the third arc-shaped sidewall gradually widens into an arc-shaped funnel shape. This creates a high-pressure dynamic pressure zone at the narrow front end of the arc-shaped funnel shape and a low-pressure dynamic pressure zone at the rear end. As the arc-shaped funnel shape gradually expands, the static pressure of the airflow gradually increases, improving the smoothness of the flow field and increasing the wind speed. As a result, the airflow is further evenly diffused by the guidance of the second arc-shaped sidewall.

[0010] Preferably, the junction of the first arc-shaped sidewall and the third arc-shaped sidewall forms an acute angle, and the acute angle is rounded.

[0011] Preferably, depending on the size and specifications of the evaporator, at least two sets of centrifugal fans are arranged side by side. In order to enable adjacent centrifugal fans to supplement each other's air volume, a gap is left between the air outlet of the volute and the front end of the evaporator, and the gap ranges from 10 to 30 mm.

[0012] Preferably, in order to improve the uniformity of air intake in the evaporator, the gaps between the front ends of at least a number of fins of the evaporator and the air outlet of the volute are not the same.

[0013] Preferably, the evaporator fins consist of alternating long and short fins.

[0014] A freezer includes a cabinet body having the aforementioned flat air duct structure, wherein the flat air duct structure is disposed at the top of the inner cavity of the cabinet body, and the air inlet of the volute is located at the top of the inner cavity of the cabinet body.

[0015] Preferably, the cabinet interior cavity is provided with a back panel, and a second air duct is formed between the back panel and the back side wall of the cabinet interior cavity from top to bottom. The second air duct is connected to the air outlet of the first air duct. The back panel is provided with multiple sets of exhaust vents at intervals from top to bottom, and the density of the exhaust vents gradually increases from top to bottom.

[0016] The beneficial effects of this invention are: compared with the prior art, the cooperation of the first arc-shaped sidewall, the second arc-shaped sidewall and the third arc-shaped sidewall can smoothly reverse and evenly diffuse the airflow delivered by the impeller to the evaporator, ensuring that the airflow can smoothly and evenly enter the evaporator, improving the utilization rate of the evaporator and avoiding frost blockage. Attached Figure Description

[0017] Figure 1 Fluid simulation renderings of a volute structure constructed using existing technologies; Figure 2 The centrifugal fan and evaporator in the embodiments of the present invention are three-dimensional. Figure 1 ; Figure 3 The centrifugal fan and evaporator in the embodiments of the present invention are three-dimensional. Figure 2 (The bottom plate of the volute is omitted); Figure 4 This is a bottom view of the centrifugal fan and evaporator in an embodiment of the present invention (the bottom plate of the volute is omitted). Figure 5 This is a bottom view of the impeller and volute in an embodiment of the present invention. Figure 1 (The bottom plate of the volute is omitted); Figure 6 This is a bottom view of the impeller and volute in an embodiment of the present invention. Figure 2 (The bottom plate of the volute is omitted, and auxiliary schematic lines are shown.) Figure 7 This is a perspective view of the volute in an embodiment of the present invention (the bottom plate of the volute is omitted). Figure 8 This is a partial cross-sectional view of the freezer in an embodiment of the present invention; Figure 9 This is a cross-sectional structural diagram of the freezer in an embodiment of the present invention; Figure 10 This is a schematic diagram of the assembly of the flat air duct structure and the back plate in an embodiment of the present invention; Figure 11This is a fluid simulation diagram of the volute in an embodiment of the present invention.

[0018] In the diagram, 10 is the first air duct; 20 is the centrifugal fan; 21 is the impeller; 22 is the volute; 23 is the first arc-shaped sidewall; 24 is the guide bend; 25 is the second arc-shaped sidewall; 26 is the third arc-shaped sidewall; 27 is the narrow air outlet area; 28 is the wide air outlet area; 30 is the evaporator; 40 is the cabinet; 41 is the back panel; 42 is the exhaust vent; and 50 is the second air duct. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] As attached Figure 1 The figure shows a fluid simulation effect diagram of constructing a volute in the prior art. The simulation software used is SolidWorks Flow Simulation (CFD computational fluid dynamics simulation). The speed of the centrifugal fan is set to 1800 rad / s. Referring to the fluid simulation effect diagram, it is obvious that the streamline distribution on both sides of the air outlet is not uniform. That is, the air volume on both sides of the air outlet is not uniform. Turbulence is more likely to occur on the side with larger air volume.

[0021] As attached Figure 2-10 As shown, the present invention provides a flat air duct structure, comprising: The first air duct 10 is equipped with a centrifugal fan 20 and an evaporator 30. Centrifugal fan 20 includes impeller 21, motor and volute 22; The air inlet of the evaporator 30 is opposite to the air outlet of the volute 22. The air inlet of the volute 22 is located on the bottom plate of the volute 22. The airflow sent out by the impeller 21 will enter the evaporator 30 through the air outlet of the volute 22. The impeller 21 is offset from the center of the volute 22, and this offset distance is no greater than the diameter of the impeller 21, so that the air outlet of the volute 22 forms a narrow and a wide air outlet area. The air outlet direction of the impeller 21 near the narrow air outlet area 27 gradually moves away from the evaporator 30, while the air outlet direction of the impeller 21 near the wide air outlet area 28 gradually moves towards the evaporator 30. The sidewall of the volute 22 is composed of three arc-shaped sidewalls, including: The first arc-shaped sidewall 23 is opposite to the narrow air outlet area 27. The curve formed by its vertical projection is a circular arc with a fixed radius. On one side of the narrow air outlet area, a guide bend 24 is formed on the inner side of the first arc-shaped sidewall 23. The second arc-shaped sidewall 25 is opposite to the wide air outlet area 28; The third arc-shaped sidewall 26 is smoothly connected at both ends to the first arc-shaped sidewall 23 and the second arc-shaped sidewall 25, respectively.

[0022] Specifically, when the motor drives the impeller 21 to rotate, it drives the external air to enter the volute 22 through the air inlet on the bottom surface of the volute 22. Under the push of the impeller 21, the air is transported to the surrounding area of ​​the impeller 21 and forms a dispersed airflow. Among them, the airflow flowing towards the third arc-shaped sidewall 26 and the second arc-shaped sidewall 25 will be smoothly reversed and evenly dispersed under the guidance of the third arc-shaped sidewall 26 and the second arc-shaped sidewall 25 and transported to the evaporator 30 from the wide air outlet area 28 side. Meanwhile, the airflow flowing toward the first arc-shaped sidewall 23, under the guidance of the guide bend 24, will also smoothly change direction and be evenly dispersed from the narrow air outlet area 27 to the evaporator 30. Compared with existing technologies, the cooperation of the first arc-shaped sidewall 23, the second arc-shaped sidewall 25 and the third arc-shaped sidewall 26 can smoothly reverse and evenly diffuse the airflow delivered by the impeller 21 to the evaporator 30, ensuring that the airflow can smoothly and evenly enter the evaporator 30, improving the utilization rate of the evaporator 30 and avoiding frost blockage.

[0023] Furthermore, in order to improve the smoothness of airflow reversal and the uniformity of diffusion, the curve formed by the vertical projection of the second arc-shaped sidewall 25 is an Archimedean spiral, and the curve formed by the vertical projection of the third arc-shaped sidewall 26 is a circular arc with a fixed radius. As attached Figure 6 As shown, the circle containing the curve formed by the vertical projection of the third arc-shaped sidewall 26 (see attached diagram). Figure 6 The circle shown by the dashed line on the right side of the middle section), and the circle containing the curve formed by the vertical projection of the first arc-shaped sidewall 23 (see attached diagram). Figure 6 The circle formed by the vertical projection of the third arc-shaped sidewall 26 is tangent to the curve formed by the vertical projection of the second arc-shaped sidewall 25, and the point of tangency is the connection point. The curve formed by the vertical projection of the first arc-shaped sidewall 23, and the tangential extension line near the impeller 21 (see attached image). Figure 6 (As shown by the dashed straight line) extends towards the wide air outlet 28 and is tangent to the impeller 21. The other end of the curve formed by the vertical projection of the first arc-shaped sidewall 23 is tangent to the air inlet direction of the evaporator 30.

[0024] Furthermore, the polar coordinate equation of the curve formed by the vertical projection of the second arc-shaped sidewall 25 is: r = |480-341θ|; The range of θ is: 0 ≤ θ ≤ 5 / 18π.

[0025] Furthermore, to avoid excessive energy loss in the airflow between the impeller 21 and the third arc-shaped sidewall 26 during the output process, the curve formed by the vertical projection of the third arc-shaped sidewall 26 is not concentric with the impeller 21. Along the third arc-shaped sidewall 26, from the first arc-shaped sidewall 23 to the second arc-shaped sidewall 25, the gap between the outer side of the impeller 21 and the third arc-shaped sidewall 26 gradually widens into an arc-shaped funnel shape. This creates a high-pressure dynamic pressure zone at the narrow front end of the arc-shaped funnel shape and a low-pressure dynamic pressure zone at the rear end. As the arc-shaped funnel shape gradually expands, the static pressure of the airflow gradually increases, improving the smoothness of the flow field and increasing the wind speed. Thus, guided by the second arc-shaped sidewall 25, the airflow is further diffused evenly.

[0026] Furthermore, in order to avoid turbulence at the junction of the first arc-shaped sidewall 23 and the third arc-shaped sidewall 26 and to improve the airflow diversion effect at that point, the junction of the first arc-shaped sidewall 23 and the third arc-shaped sidewall 26 forms an acute angle, and the acute angle is rounded.

[0027] Furthermore, according to the size specifications of the evaporator 30, at least two sets of centrifugal fans 20 are arranged side by side. In order to enable adjacent centrifugal fans 20 to supplement each other's air volume, a gap is left between the air outlet of the volute 22 and the air inlet at the front end of the evaporator 30. The gap ranges from 10 to 30 mm. In this example, the gap is 13.5 mm. That is, the air volume of the wide air outlet area 28 of the volute 22 can supplement the air volume of the narrow air outlet area 27 of the adjacent volute 22 to a certain extent, making up for the problem of the small air volume in the narrow air outlet area 27.

[0028] It should be noted that when the centrifugal fans 20 are arranged side by side, if the air outlet of the volute 22 is close to the air inlet at the front end of the evaporator 30, the air volume of the two sets of centrifugal fans 20 cannot complement each other at adjacent locations. In the evaporator 30 area opposite the narrow air outlet area 27 of the volute 22, frost blockage is likely to occur due to the small air volume at lower temperatures.

[0029] Furthermore, in order to improve the uniformity of airflow into the evaporator 30, the gaps between the front ends of at least multiple sets of fins in the evaporator 30 and the air outlets of the volute 22 are not the same. That is, multiple sets of dispersing channels are formed between adjacent fins, and converging channels are formed at the front ends of the multiple sets of dispersing channels. When the airflow enters the evaporator 30 through the air outlet of the volute 22, it first enters the converging channels separately. In the converging channels, it is then diverted by multiple sets of fins and enters different dispersing channels, thereby further improving the uniformity of airflow dispersion and improving the utilization rate of the evaporator 30.

[0030] Furthermore, the fins of the evaporator 30 are composed of alternating long and short fins. By alternating long and short fins of different lengths, the gap between the front end of the fins and the air outlet of the volute 22 can be controlled.

[0031] As attached Figure 11 The figure shown is a fluid simulation diagram of the volute 22 in this invention. The simulation software used is SolidWorks Flow Simulation (CFD). The rotational speed of the centrifugal fan 20 is set to 1800 rad / s. Referring to the fluid simulation diagram, the streamline distribution inside the volute 22 is obviously more uniform and smoother. After the airflow direction is corrected by the first arc-shaped sidewall 23, the second arc-shaped sidewall 25 and the third arc-shaped sidewall 26, the airflow direction is more parallel to the air outlet of the volute 22, and the airflow is smoother. That is, it is more parallel to the air inlet of the evaporator 30, and the air inlet is smoother.

[0032] A freezer includes a cabinet body 40 with the aforementioned flat air duct structure. The flat air duct structure is located at the top of the inner cavity of the cabinet body 40, and the air inlet of the volute 22 is located at the top of the inner cavity of the cabinet body 40. Due to the physical phenomenon that cold air sinks and hot air rises, placing the flat air duct structure at the top of the inner cavity of the cabinet body 40 and having the air inlet of the volute 22 facing downwards can effectively improve the efficiency of the hot and cold air circulation within the inner cavity of the cabinet body 40 and increase the volume utilization rate of the freezer.

[0033] Furthermore, in order to ensure that the airflow can be evenly delivered downwards, a back panel 41 is provided in the inner cavity of the cabinet 40. A second air duct 50 is formed between the back panel 41 and the back side wall of the inner cavity of the cabinet 40, running from top to bottom. The second air duct 50 is connected to the air outlet of the first air duct 10. Multiple sets of exhaust ports 42 are provided on the back panel 41 from top to bottom, and the density of the exhaust ports 42 gradually increases from top to bottom.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A flat duct structure, characterized by, include: The first air duct (10) is equipped with a centrifugal fan (20) and an evaporator (30). The centrifugal fan (20) includes an impeller (21), a motor, and a volute (22); The air inlet of the evaporator (30) is opposite to the air outlet of the volute (22); The impeller (21) is offset from the center of the volute (22), so that the air outlet of the volute (22) forms a narrow and a wide air outlet area respectively. The side wall of the volute (22) is composed of three arc-shaped side walls, including: The first arc-shaped sidewall (23) is opposite to the narrow air outlet area (27). The curve formed by its vertical projection is a circular arc with a fixed radius. On one side of the narrow air outlet area, a guide bend (24) is formed on the inner side of the first arc-shaped sidewall (23). The second arc-shaped sidewall (25) is opposite to the wide air outlet area (28); The third arc-shaped sidewall (26) is connected to the first arc-shaped sidewall (23) and the second arc-shaped sidewall (25) at both ends respectively.

2. The flat duct structure according to claim 1, characterized by The curve formed by the vertical projection of the second arc-shaped sidewall (25) is an Archimedean spiral, and the curve formed by the vertical projection of the third arc-shaped sidewall (26) is a circular arc of a fixed radius; The circle containing the curve formed by the vertical projection of the third arc-shaped sidewall (26) is tangent to the circle containing the curve formed by the vertical projection of the first arc-shaped sidewall (23); the circle containing the curve formed by the vertical projection of the third arc-shaped sidewall (26) is tangent to the curve formed by the vertical projection of the second arc-shaped sidewall (25), and the point of tangency is the connection point. The curve formed by the vertical projection of the first arc-shaped sidewall (23) extends tangentially towards the wide air outlet area (28) from the end near the impeller (21) and is tangential to the impeller (21).

3. The flat duct structure according to claim 2, characterized by The polar equation of the curve formed by the vertical projection of the second arc-shaped sidewall (25) is: r = |480-341θ|; The range of θ is: 0 ≤ θ ≤ 5 / 18π.

4. The flat duct structure according to claim 2, wherein The curve formed by the vertical projection of the third arc-shaped sidewall (26) is not concentric with the impeller (21). Along the third arc-shaped sidewall (26) and from the first arc-shaped sidewall (23) to the second arc-shaped sidewall (25), the gap between the outer side of the impeller (21) and the third arc-shaped sidewall (26) is an arc-shaped funnel that gradually widens.

5. The flat duct structure according to claim 1, wherein The first arc-shaped sidewall (23) and the third arc-shaped sidewall (26) form an acute angle at their connection point, and the acute angle is rounded.

6. The flat duct structure according to claim 1, wherein At least two sets of centrifugal fans (20) are arranged side by side, and a gap is left between the air outlet of the volute (22) and the front end of the evaporator (30), the gap being 10-30mm.

7. The flat duct structure according to claim 1 or 6, characterized by The gaps between the front ends of at least a number of fins of the evaporator (30) and the air outlet of the volute (22) are not the same.

8. The flat air duct structure according to claim 7, characterized in that, The evaporator (30) has fins consisting of alternating long and short fins.

9. A freezer, comprising a cabinet (40), characterized in that, The device has a flat air duct structure as described in any one of claims 1 to 8, wherein the flat air duct structure is disposed at the top of the inner cavity of the cabinet (40), and the air inlet of the volute (22) is located at the top of the inner cavity of the cabinet (40).

10. The freezer according to claim 9, characterized in that, The cabinet (40) has a back panel (41) in its inner cavity. A second air duct (50) is formed between the back panel (41) and the back side wall of the inner cavity of the cabinet (40) from top to bottom. The second air duct (50) is connected to the air outlet of the first air duct (10). The back panel (41) is provided with multiple sets of exhaust ports (42) from top to bottom, and the density of the exhaust ports (42) gradually increases from top to bottom.

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